CA1233443A - Gripper arm and method of operation - Google Patents
Gripper arm and method of operationInfo
- Publication number
- CA1233443A CA1233443A CA000480288A CA480288A CA1233443A CA 1233443 A CA1233443 A CA 1233443A CA 000480288 A CA000480288 A CA 000480288A CA 480288 A CA480288 A CA 480288A CA 1233443 A CA1233443 A CA 1233443A
- Authority
- CA
- Canada
- Prior art keywords
- gripper arm
- jaw member
- machine
- actuating means
- jaw
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Manipulator (AREA)
- Feeding Of Articles By Means Other Than Belts Or Rollers (AREA)
- Sheets, Magazines, And Separation Thereof (AREA)
- Container Filling Or Packaging Operations (AREA)
- Controlling Sheets Or Webs (AREA)
- Collation Of Sheets And Webs (AREA)
Abstract
GRIPPER ARM AND METHOD OF OPERATION
ABSTRACT OF THE DISCLOSURE
A gripper arm includes jaw members (24,26) between which articles are engaged and from which engaged articles are released in precise placement upon a transport means. Jaw (26) is actuated by solenoid actuating means (28) acting through linkage means 130) to perform the engagement and release operations. The activation of the solenoid actuating means (28) is controlled to be dependent upon the operating speed of a machine in conjunction with which the gripper arm is used. The solenoid actuating means (28) is assisted by biasing means (122) which is preloaded to facilitate the application of a desired holding force on articles engaged between the jaw members (24,26). The jaw member (24) has a piece (162) of high coefficient of friction material embedded in a surface oriented to contact articles engaged between the jaws (24,26).
ABSTRACT OF THE DISCLOSURE
A gripper arm includes jaw members (24,26) between which articles are engaged and from which engaged articles are released in precise placement upon a transport means. Jaw (26) is actuated by solenoid actuating means (28) acting through linkage means 130) to perform the engagement and release operations. The activation of the solenoid actuating means (28) is controlled to be dependent upon the operating speed of a machine in conjunction with which the gripper arm is used. The solenoid actuating means (28) is assisted by biasing means (122) which is preloaded to facilitate the application of a desired holding force on articles engaged between the jaw members (24,26). The jaw member (24) has a piece (162) of high coefficient of friction material embedded in a surface oriented to contact articles engaged between the jaws (24,26).
Description
GRIPPER ARM AND METHOD OF OP~RA~ION
BACKGROUND OF THE INVENTION
Thls invention pQr~ains to gripper arm structures, and particularly to grlpper arm sultable S for use with insertion machine and the like.
Gripper arms have long been used with insertion machines ox the type deplcted in U.S. Patent
BACKGROUND OF THE INVENTION
Thls invention pQr~ains to gripper arm structures, and particularly to grlpper arm sultable S for use with insertion machine and the like.
Gripper arms have long been used with insertion machines ox the type deplcted in U.S. Patent
2,325,455 to A. H. William3 which is commonly assiqned herewith ~Q~. Prior art gripper arms typlcally each have flxed and movable jaw members. The fixed jaw member is usually integral with the gr;pper arm while the movable jaw is selectively operated so that articles, ah a documents or inverts, can be engaged between and released from the two jaws.
Prior art gripper arms have traditionally been mounted on two elongated shafts which extend above and along an insert track. The firs or upper shaft, which osclllates once per machine cycle, has an upper portion of the gripper arm keyed thereto so that the gripper arm osclllates toward and away from a corresponding lnsertion supply station in timed relationship with the other operations occuring at the station. The second shaft also oscillates once during each machine cycle to actuate the movable jaw member into and out of engagement with the fixed jaw membec in timed relationship with the oscillation of the gripper I, ~3~f~3 arm about the first shaft and with the rest of the machine. A cam keyed to the second 6haft act upon a connecting rod which in turn move the movable jaw member away from the ixed jaw member against the action of a ten3ion spring. The jaws are held apart in this manner until thy gripper arm it oscillated toward the corresponding in~er~ion station whereat the movable jaw i8 portioned above and the fixed jaw it po~ltloned below an inaert. The second shaft then oscillates Jo clo e the movable jaw against the fixed jaw to ngage and grip the inert the first shafk thereupon swing awry from the invert station, pulling the selected insert therefrom in a direction toward the insert track. Over the insert track the second shaft iB
osalllated to move the movable jaw member away from the mixed jaw and thereby release the insert, permltting the insert to fall onto the table of the insertion transporting mechanism.
Although only one gripper arm atructure ha been de~crlbed above, a plurality of such gripper arm are provided with an insertion machine, each gripper arm being positioned in relation to corresponding invert statlons linearly arranged along an invert track. The area above the inset track is rather dense wlth mechanical parts including the two shaf tB which run through each gripper aem, as well as the associated cams and connecting rods for each gripper arm. It is a cumbersome operation to remove or replace an individual gripper arm since the arm must be removed from two shafts, each of which run the entire length ox the insert track. Moreover, dellcate mechanical ad~u~tment~ are required or each gripper arm 50 that thP movable jaw member associated therewith can be opened properly by gradual cam action taking into consideratlon the thickness ox the insert material in the hopper of the corresponding insert station.
--l i %3~ ,3 Insertlon machine of the tylpe described above can operate through a range of ~peed~O An operator may at a lower end o the ope.rational speed range "step" or "jog" the maahine through a machlne S cycle at a very slow speed a l u~ful in the aase o settlng up the machlne with new materi,al. At high operational speeds the insertion machine may operate at a rote in the neighborhood ox 10,000 cycle per hour.
In setting up an insertion maahine, the operator mutt be cognizant ox the fact that each lnGert must be released at a preclse location along the invert track, usually wlthln 1/8 inch of a specified precise location. The time delay associated with the actuation of the movable jaw member thus becomes a factor in determinlng where on the insert track the lnsert will be released. It the delay time in actuating the movably jaw member it constant regardless of the operational speed of the m~chine~ siynlficant error can occur in placement of the inert on the insert track.
For example, a delay ox 20 to 25 m~lllseconds in actuating the movable jaw member when the insertion machine it operating at 10,000 cycles per hour results ln the gripper arm travelling approximately one inch..
Thus, a given magnitude of time delay in actuating the movable jaw member in the jog mode or a low speed is not suitable for higher operational speeds and can, when the machine is operated at higher speeds r regult in significant misplacement of the insert on the insert track.
In view of the oregoing, it is an object of the present invention to provide a gripper arm whereln the magnitude of delay involved in actuating a movabla jaw member ls related to the operational speed of the insertion machlne in conjunction wlth which the gripper arm is employed
Prior art gripper arms have traditionally been mounted on two elongated shafts which extend above and along an insert track. The firs or upper shaft, which osclllates once per machine cycle, has an upper portion of the gripper arm keyed thereto so that the gripper arm osclllates toward and away from a corresponding lnsertion supply station in timed relationship with the other operations occuring at the station. The second shaft also oscillates once during each machine cycle to actuate the movable jaw member into and out of engagement with the fixed jaw membec in timed relationship with the oscillation of the gripper I, ~3~f~3 arm about the first shaft and with the rest of the machine. A cam keyed to the second 6haft act upon a connecting rod which in turn move the movable jaw member away from the ixed jaw member against the action of a ten3ion spring. The jaws are held apart in this manner until thy gripper arm it oscillated toward the corresponding in~er~ion station whereat the movable jaw i8 portioned above and the fixed jaw it po~ltloned below an inaert. The second shaft then oscillates Jo clo e the movable jaw against the fixed jaw to ngage and grip the inert the first shafk thereupon swing awry from the invert station, pulling the selected insert therefrom in a direction toward the insert track. Over the insert track the second shaft iB
osalllated to move the movable jaw member away from the mixed jaw and thereby release the insert, permltting the insert to fall onto the table of the insertion transporting mechanism.
Although only one gripper arm atructure ha been de~crlbed above, a plurality of such gripper arm are provided with an insertion machine, each gripper arm being positioned in relation to corresponding invert statlons linearly arranged along an invert track. The area above the inset track is rather dense wlth mechanical parts including the two shaf tB which run through each gripper aem, as well as the associated cams and connecting rods for each gripper arm. It is a cumbersome operation to remove or replace an individual gripper arm since the arm must be removed from two shafts, each of which run the entire length ox the insert track. Moreover, dellcate mechanical ad~u~tment~ are required or each gripper arm 50 that thP movable jaw member associated therewith can be opened properly by gradual cam action taking into consideratlon the thickness ox the insert material in the hopper of the corresponding insert station.
--l i %3~ ,3 Insertlon machine of the tylpe described above can operate through a range of ~peed~O An operator may at a lower end o the ope.rational speed range "step" or "jog" the maahine through a machlne S cycle at a very slow speed a l u~ful in the aase o settlng up the machlne with new materi,al. At high operational speeds the insertion machine may operate at a rote in the neighborhood ox 10,000 cycle per hour.
In setting up an insertion maahine, the operator mutt be cognizant ox the fact that each lnGert must be released at a preclse location along the invert track, usually wlthln 1/8 inch of a specified precise location. The time delay associated with the actuation of the movable jaw member thus becomes a factor in determinlng where on the insert track the lnsert will be released. It the delay time in actuating the movably jaw member it constant regardless of the operational speed of the m~chine~ siynlficant error can occur in placement of the inert on the insert track.
For example, a delay ox 20 to 25 m~lllseconds in actuating the movable jaw member when the insertion machine it operating at 10,000 cycles per hour results ln the gripper arm travelling approximately one inch..
Thus, a given magnitude of time delay in actuating the movable jaw member in the jog mode or a low speed is not suitable for higher operational speeds and can, when the machine is operated at higher speeds r regult in significant misplacement of the insert on the insert track.
In view of the oregoing, it is an object of the present invention to provide a gripper arm whereln the magnitude of delay involved in actuating a movabla jaw member ls related to the operational speed of the insertion machlne in conjunction wlth which the gripper arm is employed
-3~-An advantage ox the present invention ifl the provlsion of a gripper arm having a movable jaw member capable o engaging articles regardless o the thickness of the articles.
Another advantage ox the present invention is the provlsion of a gripper axm which is easily manufactured, in~talledt and removed for serviaeability reason.
Yet another advantage of the present l invention i5 the provision of a gripper arm which has few moving part, low mass, few lubrication poln~, and few point of frictlon and wear.
A further advantage of the present lnvention is the provision of a gripper arm wherein the coefflclent o friction between an insert and a jaw member it increased, thereby increaslng the force available to pull an insert from a hopper of a corresponding insert station but wlth less strain on the gripper arm.
Still another advantage of the present invention it the provision of a gripper arm having a movable jaw member which tightly grip inserts regardless of insert thickness Yet another advantage of the present invention is the provision of a gripper arm which, when installed in an insertion machine, facilitates easy acces3 to and around an invert track s~f the insertion machine .
SUMMARY
A gripper arm include3 jaw members between which articles are engaged and from which engaged articles are released in precise placement upon a transport means. Actuating means preferably in the form of solenoid means is used to selectively move a 3!i 5econd jaw member toward and away from a if jaw member in connectlon with the engagement and release 3Æ~3 operations. In view of the act that the actuating means mutt be activated for diferent lengths o time when the gripper arm it operated at d1f~ering peed in order to result in precise placement a,f an article upon the transport means, the timing of the activation of the actuating means 1R controlled to be dependent upon the operating speed of a machine in conjunction with which the gripper arm it used.
In the above regard, jaw actuator control means includes first sensor means or determining a machine cycle rate; second sensor means for determining when during each machine cycle the actuating means should be selectively enabled and disabled; and, meanR
fur determining a suitable machine cycle rate-dependent delay interval between the determlnation made by the econd sensor means and the actual selective enablement and disablement of the iaW actuating means. In a preferred embodiment, the delay determining means comprise an up/down counter enabled to count up pulses prom a clock1ng means and, when allowed to do so by the second 3ensor means, to count down pulses geneeated ln accordance with the second sensor mean.
In another embodiment a jaw member ha a piece of high coefficient of friction material embedded in a surface oriented to contact articles engaged between the jaws, BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and advantages of the inven~lon we 11 be apparent f rom the following more particular descript1On o the 5 preferred embodiment a illustrated in the accompanying drawing in whlch reference character refer to the same parts throughout the varlou~ view.
the drawing are not nece3~arily to scale, emphasis instead belng placed upon illustrating the prlnciples 10 of the invention.
FIG. 1 is a d{ agrammatical view of portion of an insertlon machine according to an embodiment of the inventlon;
FIG. lA is a rear view of a gripper arm according to an embodiment of the invention;
FIG. lB it a side view taken along the lone O of the gr$pper arm of ~19. lA;
. FIG 2 l an exploded view of the gripper arm of another emb~dlment o the invention;
FIG 3 is a cirault diagram showing actuator control mean3 according to an embodiment of the invention;
FIG. 4 is a graph showing various parameters as functions of machine cycles when a machine is operating at 4t500 cycles per hour;
FIG. 5 is a graph showing various parameter a function of machine cycle3 when a machine 1 operating at 10~000 cycles per hour;
FIGS. 6A and 6B are rear and side vlews, respectively, of a Hall Effect device according to an embodlment of the invention;
IGS. 7A and 7B are front and side views respectively, of magnetic mean according to an embodiment of the inventlon;
~233~
FIG. 8 is an illustrative b1ock diagram of mistake cletector fc)r a plurality of griLpper arm according to an embodiment of the inventiorl;
FIG. 8A is a schematic dlagram depicting 5 electrical circuitry included in the mistake detector of Fig. 8;
F IG . 9 i s a g r aph how i ng ou tpu t vol tag e f rom a Hall Efe~t ~en~or as a junction of insert thickness according to an embodiment of the invention FIG. 10 it a schema~cic diagram depicting the relationship of jaw members and magnetic means relative to a p1vot point;
FIG. 11 is a detailed view of a portion of the gripper arm of Fig. lA;
FIG. 12A is a detailed rear view o a portlon of the gripper arm of Fog. lA;
FIG. 12B is a detailed view of a portion of the gripper arm of Fig. 12A cut along the line ED";
FIG. 13 it a wide sectional vlew showing first sensor means and second sensor means mounted in relation~h~p to main drive hat means;
FIG, 14 it an end view of an actuator timing disc included in a second tensor means; and, FIG. 15 it a graph showing solenoid force requirements and spring force requirements as functions both of solenoid and upper jaw member positions according to an embodiment ox the invention.
DETAILED DESCRIPTION OF THE DR~INGS
Referring to Fig. 1, there is shown an insertion machine 10 which collects a plurality of inert into a pile and transport what pile to an inverting station IS; conveya an open envelope to inserting station IS; and, then insert3 the pile of lnserts into the envelope. Turing steps unillustrated ~'J
~3~3 .
~6--in Fig. 1 the insertion machine 10 later seal the envelope and pro~e~e~ the envelope or malling. It wlll be appreclated that the operation ox machine 10 ls timed in accordance with a machlne cycle. In this respect, an indlvidual envelope require several machine cycles to be processed. With the exception of a few initlal or start-up machlne cycle, a pile of inserts it inverted into an awalting corresponding envelope at the end ox each machine cy¢le.
In order for insertlon machlne 10 to collect a pile of insert at inverting 3tation IS, there ar,e provided therein a plurality of insert stack stations or hoppers Sly S2, and S3 and a plurallty of corresponding gripper arms 161, 162, and 163 each mounted to a shaft 17 which extends over an insert raceway 18. Insert statlon Sl, gripper arm 161, and shaft 17 serve to wlthdraw one insert from the tack ox insert and drop that in~er~ onto'raceway 18r More particularly, invert station Sl holds a tack of inserts Il on a manner whereby the bottommost invert i8 separable from the rest of the tack Gripper arm 161 is connected to shaft 17 which oscillates once during a portion of each machine cycle in order to rotate arm 161 toward and away from the tack of inserts While rotating toward the stack5 the jaws of gripper arm 16 are opened to allow the art to engage the bottQmmost insert When the shaft 17 stops moving arm 161 toward the stack, the jaws are closed to engage the bot0mmo3t insert. Shaft 17 then rotates gripper arm 161 away 3G rom the tack, thereby withdrawing the invert from the bottom of the stack. Gripper arm 161 then opens its jaws to release the insert which fall3 onto invert raceway 18. Thus, insert station 51; gripper arm 161, and shaft 17 cooperate to withdraw one lnsert from the tack and drop that insert onto raceway 18.
Insert raceway 18 include a pIurallty of palrs ox pusher pins P which are mounted on a palr of chalns snot shown) whlch are perlodlcally drlven by machine 10. The chains are drlven once during a portion of each machine cycle and move the pusher pins P to the next lnser~ stat;on. Ater the ju~t-described dropping of an insert from station Sl onto raceway 18, for example, pin P push the insert to the vicinity of the lnsert talon S2 and top.
In view of the foregoing, it wlll be teen that invert ~tation~Sl, gripper arm 161, shalt 17, and raceway 18 cooperate to withdraw one insert from the stack and convey that in ert to station S2. It will be appreciated that for the embodiment 3hown one insert from station Sl is conveyed to statlon S2 each machine cycle.
Insert station S2, grlpper arm 162, and shaft 17 cooperate in a similar manner insert ~tatiun Sl, gripper arm 161, and shaft 17 and serve to withdraw one 2~ invert from the stack o inserts at talon S2 and drop that insert onto raceway 18~ More particularly, insert stack station So holds a stack of inserts I2 in manner whereby the bottommost insert is separable from the rest of the ~tackO Gripper arm 162, which is also connected to oscillating shaft 17, rotates toward the bottommo~ insert; grab that insert; rotates away from the stack; and, then releases the lnsert. This insert fall ontb insert raceway 18 which already contains an insert Il. Pusher pins P of raceway 18 advance this pile to the next insert station. thus, during another machine cycle, invert station S2, gripper arm 162, shaft 17, and raceway l cooperate to add an insert I2 to insert Il and convey the pile to station S3.
Invert station S3, gripper arm 163, and shaft 17 cooperate in a similar manner as insert station 51 --8~
and S2, grlpper arm 16~ and 162, and shaft 17 and verve to wlthdraw one insert from the tack o 1nserts at stat10n S3 and drop thaw inert onto raceway l Invert stack station S3 separates the bottommo~t invert rom the rest of a tack of inverts I3. Gripper arm 163 rotate Howard the bottommost inse!rt; grabs that insert; rotate3 away from the stacks and, releases the lnsert onto inserts Il and ~2 on raceway lB. This thereby completes the pile of inserts. ~acsway 18 then conveys the completed pile Jo inserting statlon IS.
Thus, during a thLrd machine cycle inert 3tation S3, gripper arms 163, shaft 17, and raceway 18 cooperate to add an invert I3 to a pile of insert and convey 'che pile to inserting station IS.
In view ox the foregoing, it will be seen that insert stack stations Sl, S2, and S3, respective gripper arm 161, 162, and 163, and insert raceway lB
cooperate to collect a pile of hefts and convey that pile to nserting station IS in three machine cycle .
A mentioned above, insertion machine 10 convey an open envelope to inverting station IS. To this end there are provided an envelope tack ~atlon ES; an envelope flap opening ~tatlon ~0; a flap hold down bar 19; and, an envelope raceway 21~ Envelope stack statlon ES holds a stack of envelopes; separates the bottommo~t envelope from the rest of the stack;
and, feeds the envelope to a clamp C in envelope raceway 21. Envelope raceway 21 includes clamp C which is mounted on a chain snot shown) which is periodically drlven by machine 10. The chain iB driven once during a portion oE each machine cycle and moves the envelope to an enYelope flap opening station EO. At station EO, a sucker cup (not shown) rotates toward the closed flap of an envelope, applies a vacuum to the flap and rotates away f rom the envelope in order to open the ~33~3 _9_ flap ox the envelope. The raceway 21 then moves the envelope to the inserting sta~1on IS while the flap of the envelope ls held down by bar 190 When an envelope and a pile o inserts are at inserting station IS, insertion machine 10 inserts the pile of 1nserts into the opened envelope. .To this end, there are provided in machlne 10, a pusher arm PA and a vacuum bar VB. The vacuum bar VB lifts up the back (top) wide of the envelope end shaft 17 rotates and thereby moves pusher arm PA toward tha opened envelope As a result, the pile of inverts will be pushed ho the envelope. Thua, pusher arm PA and vacuum bar VB cooperate to invert a pile ox inverts into an opened envelope at inserting station IS, although Fig. 1 shows an insertion machine with three insert stack stations Sl, S2, and S3, it should ye understood that the number of lnsert stack stations 13 not critical Jo the prevent 1nven~ion and what In other embodiments fewer or more such invert station are employed along a suitable raceway.
A discussed hereinbefore, during the operation ox machine 10 it i8 highly d~irable to provide an indication when one of the gripper arms grips too few or too many inserts. Insertion machine 10 includes an improved double/miss detector which is relatively easy to calibrate and adjust and which is described in detail below.
In additionJ it should be appreciated that it is desirable to provide a reliable gripper armO
Insertion machlne 10 includes a reliable gripper arm which will now be described.
~L~3;~ 3 GRIPPER ARM MECHANICAL STRUCTURE
Each grlpper arm 16 according to an embodiment of the invention includes a houslng 20;
securing means 22 for securiny the grlpper arm to osclllating drlve means such as heft 17~ A fist article-contacting or jaw member 24; a second article-contacting or jaw member 26S jaw actuation means, suGh as solenoLd actuation mean 28; and, linkage means 30. Flgs. lA and lB (as well as Figs. 11, 12A, end 12~) show a gripper arm ac¢ord~ng to one embodiment of the inventivn while Fig. 2 shows a gripper arm of a second embodiment which is generally similar Jo the embodiment of Figs. l but which includes different structure for ~t3 linkage means. Structural element common to the embodiment of Fig. lA and lB and Fig 2 ar¢ assigned the tame reference numeral3 for description purpose3 hereinafter.' Gripper arm housing 20 has a distal end 32 and a proxlmal end 34. The means 22 for securing the gripper arm to the oscillating drive shaft 17 include (l) a aemi-cylindrlcal recess 3~ at the top of the proximal end 34 of the gripper arm housing 20, and (2) a clamp member 3B. The recess surface 36 is contlguou~
with flanges 40 on either s$de o the recess 36~ The flanges are generally parallel to the major cylindrical axis of the recess 36. The clamp member 38 mates with the proxlmal end 34 of the housing 20. The clamp 38 it formed with comparable flanges 42 which mate with the flanges 40 of housing 20. The clamp 38 has a cylindrical sector portion 44 which forms a semi-cylindrical recess 46. Each ox the 1anges 40 and 42 have two threaded apertures thereln appropriately aligned to receive threaded fasteners 48. In this respect, flanges 40 have aperture 50 and flange 42 ~3~ 3 have aperture3 52. The fa~ener~ 4~ secure clamp 38 to the proximal end 34 of the housing 20 so that the gripper arm is clamped onto the oscillating drive shaft 17. Each threaded fastener 48 extends through the aligned aperture 50,52 and the housing flange 40 and the clamp flange 4~, respectlvely.
The gripper arm housing 20 comprises opposing side panels 54 which extend the helght 5f the gripper arm. The two side panel 54 define a space therebetween. At the proximal end 34 of the gripper arm housing 20 the wide panels 54 are parallel and separated by a distance A as shown ln Fig. lA. it the mid-section o the gripper arm hou~i~g the slde panels 54 begin to converge to one another but separate beore dolng so and continue in parallel manner to the do stal end 34 o the housing 20. A thy distal end ox the housing the 3ide panel 54 are spaced apart at a dl~tanc:e B whlch i le3~3 than distance A a shown in Fig . lay, .
In the region where the wide panel 54 are separated by the distance A, a fronk panel 56 it integral with the wide panels 54. In this region where the wide panel 54 are separated by the dis'cance A, each side panel 54 has at its back a perpendicularly extending flange 58. Each flange 58 has two threaded aperture 60 therethrough, as well a3 a vertically extending channel 6~ at the intersection of the plane which includes the lnterior surface of the hou~ing-side panel 54 and the plane which includes the flange 58.
The gripper arm housing 20 also includes a backplate 64 which has a back member 66 and a base member 68 perpendlcular thereto The back member 66 has four aperture 70. Two of the apertures 70 are on each side of the back member 66, each aperture 70 being aligned with apertures 60 on the ~id0 panel flanges 58 ~33~
when the back member is a sembled to housing 20.
Threaded fastener 72 extend through the aperture 70 of backplate 64 and through the aperture 60 o the side panel flange 58 to aecurs the backplate 64 to the geipper arm housing 20. The base member 68 ox the backplate 64 is adapted for placement between the side panels 54 in an area where the 3ide panels begin Jo ¢onverge~
As described above, the side panels 54, front plate 56, back member surface 56, and backplate base member 58 generally refine a hollow volume 74. Volume 74 ls not totally confined, however, inasmuch as the base member 68 of the backplate 64 ha an aperture 76 thereon and the height of the back member 66 of backplate 64 $~ such as to leave an essentially rectangular gap 78 above the backplate 64.
Volume 54 houses the jaw actuatiny meana which, ln the illustrated embodlmént; it solenoid means 28. The solenoid mean 28 has an essentially 2~ cylindrical casing 80. Solenoid cawing 80 has a mounting plate 82 secured thereto. In the embodlment shown, the mounting plate 82 has protrusions 84 thereon adapted to fit into the channel 62 of the side panel flanges 58. As shown in Fig. 2, electrical leads 86 extend from the interior ox the solenoid casing 80 and are included in a ribbon-type cable 907 Although not shown a5 such ln Flg. lA, it should be underskood that the ribbon cable 90 extends from the volume 74 out through the rectangular gap 78 on the back of the tripper arm and is connected Jo appropriate circuitry including the type of circuit shown in Fig. 3, the circuitry to which the ribbon cable 90 l connected resides on a circuit board or the like situated elsewhere on the particuiar machine in conjunctlon with which the gripper arm of the invention operatesO
33~3 Toe ~oleno~d mean 28 alto compr1se~ a plunger means 92. Near it bate plunger mean 92 ha an annular groove about which C-clamp rleta1ner 96 f lt~o the lower end o the plunger 92 'ha a slot 98 S therein through the diameter o the plunger 92. The plunger 92 alto has an aperture 100 extending therethrough along a diameter of the plunger 92 which is transverse to the slot 98. The plunger aperture :L00 it adapted to receive a rollpin 102.
Turning now to the embodlment of Fig. 2, the llnkage mean 30' comprises a biasing means and a connecting rod 120. The biasing means includes a cylindrically coiled inner spring or extension sprung 12?. having coils formed generally in planes perpendicular to the major axis of the cylinder. The ~nnee ping 122 has flr~t and second ends formed in ~ing-llke fashion, the end ring being formed ln plane ln which the axis of the cylinder lie (that iB, the planes of the end rings are generally perpendlcular to the planes of the coil included on inner spring 122~. Ring 124 at the upper end of the inner spring 122 is adapted to receive pin 102 therethrough when the ring 124 it inserted into the slot 98 of the plunger 92. Ring 126 at the lower end of the inner spring 122 i8 adapted to receive a pln 128. Lower ring 126 receives pin 128 whey the lower ring 126 is inverted into a tran~ver~e slot 130 formed in a irst end of end cap 132. End cap 132 has an aperture 134 through the diameter whereof which intersect the lo 130 ln perpendicular ~a~hion in a manner similar to the slot 98 on apertures 100 ox the plunger 92.
End cap 132 has an annular shoulder 136 near its mid3ection BO that an outer pring 13~ can be confined between the shoulder 136 and the base member 68 of the backplate 64. Thus, the outer ~prlng 138 ls ~L~33~
ox greater diameter hart toe inner spring 122 and fits ln concentric Eashion over the inner sprlng 122. the outer spring 138, according to one mode of the lnven~ion, preloads the inner expansion spring 122 by S stretching spring 122 a desired distance 50 that spring 122 cause jaw 26 to exert a force of a desired magnitude on insets engaged between jaws 24 and 26.
A further seen in Fig. 2, the lower end ox the end cap 13~ receives a threaded top 1~0 of the connecting rod 120. The connecting rod 120 extends between planes ln which the do panel 54 are lncluded downwardly toward the distal end 32 o the housing 20. The rod crooks outwardly to the side at polnt 142 as it extends downwardlyl and when bend inwardly to have a por~lon 144 in horizontal orientation at the lowest extent of its travel. the lower end 144 of the rod is adapted to receive a lock member, such as C-clamp retainer 146.
The dial end 32 of the gripper arm housing 30 has, in the Fog. 2 embodiment shown, a first jaw member 24 which i6 formed lntegral with the housing 20 a a lower jaw member. A rectangular recess 160 ig Çormed in a surface of the jaw 24 which is oriented to contact an article to be engaged by the gripper arm.
rrhe recess 160 is adapted to receive a piece of high coeficient of friction material, such as a piece of urethane 162.
The second jaw member 26 as shown in Fig. 2 comprises a block 170 insertable in a space defined by the separated lower ends of the side panel 54. The block 170 has a protruding curved member 172 extendlng therefrom, the underneath surface of which contacts article to be engaged by the grlpper arm. Block 170 also has two aperture 174 and 1~6 extending therethrough. The aperture 174 l adapted to receive a ~%33~
-lS-pivot pln 17B so that the second jaw member 26 can pivot about the pln 17~. rrhe 0econd aperture 176 it adapted to receive the horizontally extending lower end portion 144 of the connectins rod 122.
The pivot pin 17~ i5 received not only through aperture 174 in the jaw member 26, but also through aligned apertures 180 ln the distal end of the slde panels 54. Thus, when the seaond jaw member 26 is lnserted in the space between the side panel 5~ near lQ the dl~tal end 3~ of the gripper arm houzing 20, the aperture 174 and 180 are aligned BO that the pivot pln 178 can freely fit therethrough. The plvot pin 178 it retained in position by a set screw 181 so that the plot pin 178 rotates in bearing-like end cap5 182.
lS The embodiment of Figs. lA and lB differs tightly from the embodiment of Flg. 2, ln the configuratlon of the partlcular linkage means utilizedO Whlle the embodiment of Figs. lA and lBj like that o Fig. 2, ha an inner spring 122, the inner spring 122 of the embodlment of Fig. lA and lB i5 positioned ln a cylindrical spacer or sousing 202. As ¦ in the Fig. 2 embodlment, the upper ring 124 of the l inner sprlng 122 it secured by plunger pin 102 to the I solenoid plunger ~2. The top of the cylindrical 251 housing 202 abuts the lower end of the plunger 92.
! The lower end of cylindrical houslng 202 abuts a retaining rung 203. The re~alning ring 203 is carrled ln an annular rece 5 on a clevis-type end cap 204. The pin 128 extends radially through the end cap 20~ in a manner understood from the description of the end cap 132 of Flg. 2. End cap 204 axially receive a ; pin 205 which has an upper exterlor portion thereof ! threaded or engagement in an axial aperture of end cap 1 204. An upper end o a cable 206 is connected to the 35 1 lower end of pin 205. Cable 206 extends rom the pin 'I
205 to the distal end 32 of the grlpper jAW. At it lower end the table 206 ha a ball 208 fixedly attached thereto.
Located in the cylindrical housing 202 in the manner described above, the inner spring 12~ of Flgs.
lA and lB i3 held so that it it generally extended about D.25 inches beyond i~B length a rest. The spring 122 is thua preloaded to h~Ye a desired sprung force For the embodiment of Fig. lA and lB and 11, the upper jaw member 26 comprlses a block member 210 and a curved protrusion 212. The underside of the protrusion l used to contact articles engaged by the gripper arm. The block member 210 ha a narrow slit 214 at the back thereof through which the lower portion ox cable 20~ extends. At the bate of the slit 214 it an essentially square chamber ~15. Chamber 215 hove ball 2n80 When cable 206 pulled upwardly the ball 208 thereon, having a greater d~ama~er than the wLdth of the slit 214, bears agalnst the top interlor surace of the chamber 215, causing the upper jaw member 26 to pivot 50 that the upper jaw member 26 approaches the lower jaw member 24 Jo that the jaw esqent~ally closes.
The block member 210 of second jaw 26 also has three apertures 216, 218, and 220 extending therethrough. The central aperture aperture 218) accommodates a pivot pin 222 about which the jaw member 26 pivot.
The embodlment of Fig. lA and lB and 11 further comprises means or biasing the jaw member in an open posi~icnO The biasing means includes torsion spring 230 (seen in Figs. 12A and 12B). An intermediate portion of the torsion spring 230 has a helical shape whlch is concentric wlth and its over on ~;23~3 exposed end of plvot pln 222, the end olE pln 222 protruding beyond a side panel (the left ode panel a seen on Fog. 12~) of the gripper arm. A it exposed, protruding end the pivot pin ~22 has a head 232 formed thereonO A disc 234 is secured on the plvot pin 222 just inside its head 232. The helical portlon of the torsion spring extend between the disc 234 and the left side panel oP the gripper arm, A one ox it end the torsion spring 230 departs from it8 helical configuration and a~Rumes a linear shape as it extencls upwardly to a retaining pin 236 against a side of which it bear (Lee jig. 12~). At it other end the torslon spring 230 extend through a square notch 238 formed on the circumference of the disc 234. The portion of the torsion spring 230 that extend through the disc 234 bears against a corner 2~0 of the notch 238. Spring 230 bears against corner 240 to exert a biasing force on the disc 234 and the pivot pin 222 whereby the upper jaw member 26 i8 normally held open in the absence ox application of tension to the cable 206. When cable 206 and ball 208 thereon are urged upwardly, however, ball 208 bears against the upper interior surface of the chamber 215 and exert a force on block 210 which overcome3 the biasing force of the torsion spring 230 so that block 210 pivots about pin 22~, thus causing jaw 26 to clove.
GRIPPE A~M-ASSOCIATED
OPTO/ELECTRICAL STRUCTURE
Fig. 3 shows circuitry utilized in connection with the gripper jaw actuating control mean3 according to an embodiment of the invention. An encoder disc 260 and an actuator timlng disc 262 are mounted to rotat2 on a main drive shaft 263 of a machlne, such a an ~3~ 3 lnsertlon machinel in connection w1th which the gripper arm 16 of the inventiorl operates. The maln drive ~haf t rotate once per machine cycle and ha various tlming and drive means rigidly coupled thereto for power tran~mi3slon, quch a the aforementioned 03cillating driva mean 17, or example. The encoder disc 260 is a 64-tooth disc. The actuator timlng disc 262 ha us clrcumference configured to allow the passage o light (in a direction perpendicular to the plane ox the disc) about a disc central angle 266 corresponding to portion3 of a machine cycle during which the actuation means of the gripper arm it to be actuated 50 that the second jaw it either in contacting relation with the ~ir~t jaw or ha an article gripped between the first jaw and the second jaw.
Fig. 3 shows an encoder disc sensor 300 including the above-mentioned encoder disc 260 positioned to cause pa~age ox light from an LED 302 to be periodically incldent on circumferential teeth of the encoder dl c. If the light from TED 302 impinge on a tooth of the dlsc, then the light it not transmitted to receiver 304. If 2 circumferentlal space between the teeth on the encoder dlsc it allgned with a beam of light from LED 302, then the receiver 304 detect the light. An actuator timing disc sensor 306 also includes the above-mentioned actuator timing di c 262 with an ED 308 and a photoreceiver 310 similarly arranged about the ackuator timing dlsc.
The opto-interrupt receiver 304 it connected to two inverting drivers 312,314 in serles with one another. The output ox thé inverting driver 314 it connected to both input terminals vf a N~ND 316, the output ox which it connected to both i nput termlnals of a second NAND 318. The output of NAND 318 ig connected to two other NAND~ ~NAND~ 320 and 322).
I' i ~3~3 The clrculk of Fig. 3 also includes a clock or timer 324 having its clock output pin spin 3) connected to a ~ir~t input of a NAND 326. The NAND3 320 and 326 have their output terminals ¢onnected to respective input terminals of a fal~e-actuated 0~ gate 328. The output terminal ox OR gate 328 is connected to a clock input pin (pin 15) ox a delay determination means, such ag a pre~ettable up/down binary counter 33~.
.~ Up/down counter 330 ha its reset input pin connected to an output terminal and an EON gate 332.
One input of the EOR 332 is connected to ~12 volts; the other input terminal it connected to the output of RAND
3~2~
i5 The up/down directlon pin spin 10) o the counter 330 i3 connected to the Q output of a "Do Ellp-flop 3340 The set and reqet input pin3 of the flip-slop 334 are grounded. The "D" or data input pin of the fllp-~lop 334 is connected to a compare signal in the manner hereinafter described The clock input pln spin 11) of the flip-10p 334 i8 connected to the output of NAND 318.
The data input pin (pins 4, 12, 13d end 3) and pin 5 of counter 330 are grounded. Output pins 6 and 14 of the counter 330 are connected to respective input terminal of a NAND 336. The output terminal of NAND 336 Lo connected to the reset terminal (pin 4) of k timer 324~
The carry~out terminal (pin 7~ of counter 330 is connected to a first input terminal ox a NAND 338.
The second input terminal of NAND 33B it connected to an appropriate voltage eor setting initial condition for machine start-up. The output of NAND 338 it connected to a first input kerminal of an EOR 340, the other input terminal of the EOR 340 being connected to I? V
~L233~3 a ~l2 volt3~ The output ox the EOR 340 18 connected to a clock lnput pin (pin 3) o a "DN flip-flop 342, Flip-lop 342 ha its reset and jet ~erminal3 spins 4 and 6, respectively) connected to ground. Thy "Do or data terminal it connected to thlo output of inverting driver 344 and 346 which are connected in series between the receiver 310 and the fllp-flop 3~2. The Q output terminal spin l) of the flip-flop 342 it connected both to the first input terminal of an EOR gate 350 and to two inverting drivers 352 and 354 ln cries The other input termlnal of the Eon 35D Ls connected through the in~ertlng driver 344 and 346 to the re¢eiver 310 o the actuator timing do 306.
The output terminal of the EOR 350 is connected to an inverting driver 356~ The outpu termlnal of the inverting driver is in turn connected both to the data input pin spin 9) of flip~flop 334 and to the second input terminal of NAND 322.
The Q output terminal of slip flop 334 it alto connected both to the second input terminal of NAND 326 and to a f$rst input terminal o an EOR gate 358. the other input termlnal of toe EOR gate 358 it connected Jo +12 volts. the output terminal of the EQR
gate 358 is connected to thy second lnput terminal of In the illustrated embodiment, NAN~s 316, 318, 320, 322, 326, 336, 338, and false-activated OR
328 are included in a single integrated circuit chip such as a QUAD-2 Input NAND Schmitt Trigger. Counter 330 it a presettable up/down binary counter. EOR gate 332t 340, 350, and 358 are included in a quad Exclusive OR gate. Flip-flop~ 334 and 342 are lncluded in a Dual "D" Fl~p-Flop Chip. Clock 324 is a linear timer.
Inverter driver 312, 314, 344, 346, 352, 354, and 356 are included ln a 7-channel PMOS Input Driver.
~21 For the embodiment of Flg. 3, by way ox example, re~3istance values are g1ven Jo the resistors and capacitance values are given to the capacLtance~ aa shown on l:he hollowing chart:
RES I STANCES
Rl = R2 - R3 = R4 = lK
:~5 5K variable) ~6 R7 8 ~8 - 1. 2R
R9 ye R10 lûOK
Rll R12'~ ~13 - R14 = 10 R15 = 470 Ohm CAPACITANCES
Cl 0.1 F
C2 = 0.001 F
C3 1.0 C4 0~47 F
~5 - 0.01 MIgTAKE DETECTOR
A mentioned above, lnsertion machine 10 includes an improved double~mi~ mistake detector.
This double/miss detector indicates when owe of gripper arms 161, 162, or 163 qrip too ew or too many in~ertsO More particularly, a3 shown in Fig 8, there is provided a double/miss detector for each ox the gripper arms i.e., a detector 364/ 374, and 384 for lndicating when gripper arms 161, 162, and 163, respectively, grip the wrong number o inserts. Since detectors 364, 374, and 384 are substantially imilar, only detector 364 will be described in detail and it will be understood that detectors 374 and 384 wlll operate in a similar manner under simllar conditions.
~23~ L3 Detector 354 serves to detect when grlpper jaw 161 ha gripped too few or too many inserts. To this end, there are provided in deteatoL 364, a jaw displacement tensing means 366 and a mi.stake 1ndicating circuit 365. Jaw dlsp1acement sensing means 366 it mounted on the gripper ~aw~ ox arm 161 a hereinafter descrlbed and serve to generate an e1e!ctrica1 signal propor~lonal to the relative d~sp1acem~nt between the grlpper jaw. When a proper number of inserts aye known to be gripped between the gripperljaw~, a witch is closed and a Bet pu1se 1B provided to mistake indicating circuit 365 which then serves to convert the electrical signal proportional to jaw displacement to a stored reference slgna1. ThiB stored reference signal is u6ed by indicating circuit 365 during a preselected time ox a machine cycle to determine if thy electrical signal generated by ~en~ing device 366 is wlthin predetermined 1imits.
It will be appreciated that the jaws of the gripper arm are forced open prior to grabbing the insert and the jaws are forced open in order to release the in3ert~ Since Sensing means 366 continuously generates an electrlcal signal proportional to jaw displacement, it is desirable to indicate a mistake condition only during the portion of the machine cycle when the gripper jaws are holding the insert, i.e., when the inserts are being pulled from the tack. In the present embodiment, a timing signa1 is applied to indicating circuit 365 shortly after the gripper arm 30 has pulled the insert from the stack and circuit 365 indicates a mistake condition only during this enabling signal. Thus, although sensing means 366 continuously yenerates an electrical signal proportional to jaw displacement indicating circuit 365 indicates a mistake condition only when the jaws are displaced by the inserts.
To the end that mistake indicating circuit 365 may swore a reference slgnal and indicate when a proper number ox documents is not grlpped by the gripper jaws, there are provided in indicator 365, a signal generating means 367; a comparing means 368; a storing means 369; a transmission gate 370; and, a mistake ind1cator/alarm means 372. signal generating 10 jeans 367 l connected to ~en~ing means 366 and generate three electrical signals which are proportional to the signal generated by sensiny means 366. The first signal generated is proportional to the signal generated by sensing means 366 and is applled to a input of storing means 3690 The second signal generated it a 1xed percentage greater than the flr~t eignal and correspond to the lower llmit oÇ acceptable jaw displacement. the thlrd 3ignal generated i5 a fixed percentage less than the ir~t 3~gnal and corresponds to the upper limit o acceptable jaw displacement. Storing jeans 369 tore the first electrical signal from generating mean 367 during the detector set-up or calibration time and thereafter applies that stored reference to comparing mean 368.
Comparing mean 368 compares the second and third signals from generating means 367 with the stored reference slgnal from storing means 369 and generate a first electrical signal when the results ox the comparison indicate that too few inserts have been grabbed by the gripper jaw and a second electrical signal when the results of the comparison indicate that too many inserts have been grabbed by the gripper jaw. The results o comparing means 368 are applied to the input o a transmission gate 370 which Q~
~33~3 provides a mistake indicatis:n only after the gripper jaw pulls the invert from the tack.
MIST~E DETE:CT0~ SENS0~ STRUCTURE
Figs. 6A and 6B show a sensor means 400 5 which, as shown in Figs. lA and lB, is mounted near khe distal end 32 of the gripper arm 16. The sensor means 400 it included in the jaw dlsplace~en~ sensing means such as ~en~ing mean 366 of Fig 8. The sensor mean 40û include a housing block 402 havlng a rectangular channel 404 wormed on its front surface. The rectangular channel qO4 has only one edge 406 thereof extending to an edge of the housing block 402~ rrwo fastener 40B having their shats flush wlth the channel 40~ extend through the housing block 402 to secure the sen or means 400 to the gripper arm in the location depicted in Fix. lA and lB.
The Yen~or mean ~00 further include3 a aover plats 410 which as teen in the rear view of Fog. 6A has rectangular dlmen~ion~ comparable to the front rectangular dimensions of the houslng block 402. The cover plate 410 i6 secured onto the housing block 402 by an epoxy adhesive material. A sensor element 412 ls accommodated in the rectangular cavity defined by the housing block 402 and the cover plate 410. Sensor element 412 serves to sense the flux density of a .
generated field and generates an output signal proportional thereto. In one embod1ment the sensor element 412 comprises a current-carrylng electrical conductor across which a voltage is generated when the conductor it in a magnetic fîeld, the magnitude of the generated voltage being proportional to the magnetic field flux intensity. on example o this embod.~ment of sensor element 412 is a Hall Effect sensor element.
! `J
cable 413 comprislng three leads 414, 416, and 41B
extends from the sensoe element 412 to the circult of Fig. 8A as hereinafter described.
Figs. 7A and 7B show a magnetic means 420 which is included in the jaw displacement senslng mean ~uah as mean 366 and which cooperate with the senBor means 400. The magnetic means 420 includes two rare earth magnets 422 and 424, each being essentially disc shaped. Each disc-shaped magnet 422,424 is mounted in corresponding circular aperture formed in a disc-shaped holder 426 having a dlameter at least greater than the sum of the diameter of the magnets A seen in Fig. 7A, magnet 422 has it North pole exposed while magnet 424 ha lts South pole exposed. The clrcumerences of the two disc-~haped magnets come clo3e to touching on a line 428 which connects their centers.
The magnet holder 426 it further mounted on a mountlng bracket 430. Mounting bracket 430 is a thln sheet of a re~llient metal such a Spring Temper Bra. Bracket 430 it bent along a line 432 which ~epara~e an upper beacke~ portion from a lower bracket portion. In its natural state (i.e., not installed in the gripper arm 80 that no external mechanical forcez are acting on the upper portion of the bracket 430), the upper bracket portion bends away from the lower bracket portion at an angle alpha which is approx1mately 15 degrees. The upper bracket portion has the magnet holder 426 mounted therein. The lower bracket portion has three apertures extending therethrough. A central aperture 434 i9 sized to accommodate the pin 222 which functions as the pivot point about which the second jaw member pivot with respect to the first jaw member. The central aperture 434 is po~ltioned so that an imaginary line 436 3~3 --2~--extending through the diameter ox aperture 434 and con~truc~ed perpendicular to line ~28 intersect line 428 midway between the centers of magnet:s 422 and 424. The point of lntersection of the lmaginary line 436 and the llne 428 bisected thereby it; taken us the center of the magnetic f ield and labeled as point X it the drawing. Apertures 438 on either side of central aperture 434 are adapted to receive fastener3 440 which, as seen in Fig. lA, secure the magnet means 420 and particularly mounting bracket 430 of the imaginary line 436 and the lint 428 blsected whereby i8 taken as the center of the magnetic field and labeled as point:
on the drawing Apertures 438 on either slde of central aperture 434 are adapted to receive fastener }S 440 which, as seen in Flg. lA, secure the magnet meanY
420 and particularly mounting bracket 430 thereof to the second jaw means 26.
As shown in FigO lB, thé màgnetic means 420 i3 sandwiched between a gripper arm side panel on itB
one ~lde and the Be~SOr mean zoo on the other gripper arm ~lde panel on its other side. In order to be hela in the position shown in Fig. lB the resllient bracket 430 must be deflected to an essentially planar configuration rather than the configuration of Fig. 7B
which shows a bending of the upper bracket portion about an angle alpha from the lower bracket portion.
When in the assembled configuration of Fig. lBJ it i8 to be understood that the spr~ng~like resilient biasing properties of the bracket 430'urge the e~senti~lly planar ace of the disc-shaped magnet holder 426 against the essentially planar cover plate 410 of the sensor 400. As seen hereinafter w1th respect to Fig.
lB, movement of the second jcaw member 26 about pivot point 222 causes the magnetic means 420 to slide across J
~3~
the sensor mean 400, thereby changing the magnetlc yield flux detected by the sensor element 412 MISTAKE DETECTOR CIRCVITRY
As mentioned above, cable 413 extending from s the sensor mean 400 includes the leads 414, 416, and 418 which are connected to the circuit of Fig. 8A, The circult of Fig. 8A is not located on the gripper arm it~l, but on a circuit board remote from the gripper arm.
As shown in Fix, 8A, leads 414 and 418 are connected to ~12 volt and round, re~pectlvely. read 416 iB connected to a node 450 of the slgnal generating means 367. Signal generating means 367 includes a voltage division network which comprises resistor Rl6, lS ~17 and Rl8. In the voltage division network a nod 451 occur between the connection of re~istor~ R16 and Rl7 and a node 452 occurs between the connection of resistors R17 and Rl8. Node 450 is connected by a capacitor C6 to ground.
The low side of resistor Rl~ (node 451) is connected by a lead 453 to storing means 369 illustrated as a sample and hold circuit, and particularly to a non-inverting input terminal of a llnear operatlonal amplifier 4S6 included thereln. The sample and hold circuit further comprise NAND gates 458 and 460; a 14-stage binary counter 462; and, an operational ampliier 464~ The inverting input terminal of the OP AMP 4S6 is connected both to the output terminal of the OP AMP 464 and through a resistor Rl9 to the inverting input terminal of the OP
UP 464. The output terminal of the OP AMP 456 is connected to a first input terminal of the NAN 45~
The second input terminal of the NAND 458 is connected ( 3~3 by resistor R20 and capacltor C7 in 3erles both to the output terminal of NAND 460 and Jo the clock input pin of the counter 462. The second input t:erminal of the NAND 45~ s also connected to both the output terminal of NAND 458 and to a first input termirlal of NAND 460 through resistors R20 and ~21. second input terminal of NAND 460 is connected through a leacl 46~ to a lead 468 and a selectlvely closable calibration switch 467. Lead ~68, which carries a clocklng signal, i connected to a reset pin ox the counter 462 through the calibratlon switch 4~7.
Output pin 1, 2, 4-7, and 12-15 of counter 462 are each connected by one of the resistors R22 to a voltage dlvislon network. The voltage division network comprises nine resistors R23 arranged in series, tha low side of each resistor connected (through a resistor R22) to a corresponding output pin of the counter 462 and the hlgh wide connected (through a resl~tor R22) to a neighboring output pin of the counter 462. Output 20. pin 2 ox the counter 462 is connected through its associated resistor R22 to the non-inverting input terminal of OP AMP 464 and through the resl~tor ~22 and capacitor C8 to ground.
The circuit of ~19~ 8A also illustrates ln more detail thy comparing means 368; the transmission gate 370; and the mistake indicator/alarm mean 372.
In this respect, the comparlson means 368 comprises both double" comparison means (such as operational amplifier 470) and Miss" comparison means such a operational amplifier 4~0). Similarly, the transmission gate 370 comprises a "double" mistake gate (including a multivibrator such a ~Dn-type Elip flop 472) and a Miss" mistake gate (including a similar multivibra~or 482). the indicator alarm mean 372 J `J
3~3 ?
-2~
includes lnverting drivers ~74 and ~4 and respective LED3 such a "double" hED 476 and "mi0~" LED 486, th respect to clrcuit elements used to detect a l'double", the nvn-lnverting input terminal o S the OP AMP 470 is connected Jo the low wide of resistor ~17 (node 452) while the inverting input terminal of OP
AMP 470 i 8 connected to the calibrated reference slgnal occurring at the output terminal of the OP AMP 464.
the output terminal of the OP AMP 470 is connected to the data input pin of the flip~1Op 472. The set terminal of the flip~flop 47Z 18 grounded, but lt termlnal l connected to the input terminal ox the inverting driver 474. The clock pin of flip-~lop 472 i8 ultimately connected to a lead 468 which carries a tlming pulse indicatlve of the point in tlme of a machine cycle when the flip-f.lop 472 i8 to transmit the comparison result to the indicator alarm means 372 to the point in time in whirh the separation of the gripper jaw member 24 and 26 is to b* detected. The reset pin o the flip-flop 472 is connected to a lead 477 which 3electively carries a reset pulse.
The output terminal o the driver 474 is connected (1) through a re~i~tor R24 Jo t24 volts D.C.;
(2) Jo the cathode of LED 476 and through resistor ~2 to ~24 volts D.C.; and, (3) to the cathode of a diode 478, the anode of which is connected to a lead 479 which carries a signal indicative of a detected mistake to unillustrated portions of the system which have need to know of the mistake.
With the exception of the input terminals of the OP AMP 483, the element 480, 482, 484, 486, and 488 used to detect a "miss" are connected in analogous manner with the elements 470, 472, 474, 476, and 478 as described above. however, the non-inv~r~ing lnput terminal of the OP ASP 480 it connected Jo the r 3~3 -3~
callbrated reference signal occurrlng at the output ~ermlnal of the OP AMP 464 while the inverting lnput term$nal of OP AMP 480 is connected to the node 450 ~th~ high side of ee~is~or R16).
For the embodiment of the elPctrical circuitry associated with the Hall ~f~c~ sensor 400 a3 shown in Fig. 8~, operational ampliflers ~56, 464, 470, and 480 are lncluded on a quad OP AMP chip; NAND gate3 458 and 460 are included on a quad 2-inpu~ NAND Schmltt 10 trlgger chip; and, flip-flops 472 and 4a2 are included on a Dual "D" flip-flop chip. The resistor and capacitor shown in the embodiment of Fig. 8A have the values shown on the following charts:
Resistors R16 - 100 ohm R17 - 100 ohm R18 = 4.7 K
Rl9 100 X
R21 = 10 K
R22 = 200 R23 = 100 X
R24 = 10 K
R25 = 1.8 R
R26 = 10 K
-Capacitors C6 = 1 microF
C7 = 0.003 microF
C8 - 500 pico~
OPERATION
The operation ox the gripper arm and the ~3~3 mistake detector are hereinafter described. the first general phase of operation de~aribed h~rein~fter i8 khe opening ox the gripper jaw such a takes place when an insert is released for dropping onto thle raceway 18.
5 The second general phase of operation dlescribed heeeinafter l$ the closing of the gripper jaws to engage anotber insert between the gripper jaw 50 as to pull the invert from its tack at thy insert ~tation~
The third general phase of operatlon described hereinafter l the operation o the mi~t~ke detector which determines whether the proper number of inverts are engaged between the cloyed gripper jaws.
For the most part the ensuing ~iscu~sion o the operation of the gripper arm and the mi take detector a~ume~ that the normal operatlons of the insertion machine are currently on-going and that inltializatLon or set-up of the insertion machine has already taken place. what is, k operation of the insertion mach$ne is descrlbed herein a being for the most part in the middle of a job. Where appropriate, however, operating ~ep~ or re3ults that have impact or pertain to machine set-up or calibratlon are also de~crlbed. In this respect; from Flg. 4 and portion of the ensuing discussion it is understood that the operation ox a slow jog mode such as used in machine jet up isO except for matter of timing, similar to the on-going operation. Also, following the description of the operation of the mistake detector the calibration operatlon of the mistake detector it also described.
GRIPPER JAW OPENING OPERATION
At an apprvpriate point in the machine cycle when the gripper jaws 24 and 26 are engaging an invert, light from the LED 302 o opto-interrupter ox encoder ~33~3 disc sensor 300 radiates through spaces between the teeth on the encoder disc qo as to be incident upon recelver 304, caving the recelver 304 to outpuk a true signal to the inverting driver 312. Inverting driver 312 inverts the true signal to a false signa} for appllcation to inverting driver 314. Invertlng driver 314 in turn inverts the false siynal to a true signal. When the teeth of the encoder disc interrupt the light between the LED 302 and the receiver 304, a false signal appears at the output of the inverting driver 314. Thus, a the encoder di3c rotates, a series of pulses is produced. In the series o encoder pulses generated by the 6~-tooth disc, the machlne man shaft rotates 5~625 of the machine cycle (5.6~5 DMC) between the leading edges ox consecutive true signalsO The graphs ox encoder pulse trains generated in this manner appear in Figs. 4 and 5, The encoder pulse train is applied to NAND 316 and 318 ox the -circuit shown in Fig. 3.
During operation the clock 324 is generatln~
clock pulses at a frequency determined by the manner in whlch the pin of the clock 324 are connected. When connected in the manner shown in Fig. 3 and de3cribed herein, the clock 324 generates pulses at a 178 rate. Trains ox pulses from the clock 324 are shown in Figs. 4 and SO Note that in Fig. 4 there are more clock pulses relatlve to the number ox encoding pulses than shown in Fig. 5. In Fig. 4I the machine is operating at 4,500 machine cycles (MC) per hour whereas in Fig. 5 the machine is approaching 10,000 MC.
The clock pulses from clock 324 are applled to the first input terminal of NAND 326. Whenever the second input terminal of the N~ND 326 is also true, a ealse signal is applied from the NAND 326 to the false-,1 ~33~
actuated OR gate 328. When the other input terminal of the false-aGtuated OR 328 i3 true, then pulses from the OR 328 are applied to the clock lnput pin of the prese~ta~le up/down counter 330.
Counter 330 counts up when pin 10 the directional pin) is true and counts down when the directional pin i3 ale The clock pulses of carry out pin 7 of the counter 330 are seen i.n Fig. 4 and 5. In relation to the clock pulses from clock 324, the fading edge of the output pulae~ prom the counter 330 oscur sub~tant1ally at the tame time the leading edge of clock pulseR from the clock 324.
cot pin 1 of the counter 330 it ultimately connected to the encoder disc ~ensar 300, so that the 15 reset pin of counter 330 receives a train of pulses the frequency of which is related to the number of machine cycles occuring per hour. The leading edge o a pulse in this encoder traln from the EON 332 causes the counter to be feet thereby termlna~lng the output pulse from the counter 330~ Thus, a seen in Fig. 4, when the machine i5 operating relatively 510wly at a rate of 4,500 MC per hour, the counter 330 can count up a greater number of clock pulses beore it is reset by the leading edge ox an encoded pulse from the EOR
332. In the graph of Fig. 5 on the other hand, the counter 330 has sufficient time only to count up one clock pulse before b ing reset.
The above descrlption of the operation assu~e~ that the actuator timing disc mounted on the 30 machine drive shaft is ln a position to permit the passage of light prom the LED 308 to the receiver 310. Under such circumstances the actuator is activated, and hence the 11nkage 30 causes the second jaw member 26 to be urged toward a contacting relationship with the first jaw member 24. The ~33~3 -3~-actuator timing disc has patterns on its circumference to obstruct the position of light from the LED 308 to the receiver 310 at points in the machine cycle in which It is desired for the second jaw 26 to open with respect to the jaw 24 as a result of the actuator activation. When this occurs, the absence Oe light at the receiver 310 causes output from the inverting driver 346 Jo go alse. This false signal is applied to the second input of the EOR 350. The first input terminals of the OR 350 still receive a true slgnal from the flip-flop 342 since no clock pulse has been applled to the flip-flop 342 to cause the flip~flop 342 to be effected by the false signal appearing at the ED"
pin (pin 5) of the flip-~lop 342. The true gnat from the Q output of the flip-flop 342 keep3 the solenoid drive at a true level meaning that the solenoid 28 18 activated and that the jaws 24,26 retain together Since the EON 350 now receives a true signal erom the flip-flop 342 and a false slgnal from the inverting drLver 346, the output of the EON 350 goes true. This true signal is inverted by the inverting driver 356 to be false. The false signal Erom the inverter 356 i5 seen in Figs. 4 and 5 as dropping to a false level in the portion of the graph labeled compare Output".
The false signal from the inverting driver 356 li.e. the "compare output" signal) is used in two ways. First, it is used to reverse the direction of the counting of the counter 330. In this regard, the 3~ false signal from inverter 356 l applled to the data input pin (pin 9) Oe the flip-flop 334 which causes the Q output pin to go false when the next enco.ler pulse s received at the clock input pLn oÇ the flip-flop 334.
The false output Oe flip-~lop 334 at the Q terminal causes the counter 330 to change direction that is, to ~33~3 count down). Second, the false signal from the inverting driver 356 is used to keep the EON 332 prom resetting the counter 334 while the counter 334 is counting down.
As mentioned above, the false signal from the inverting driver 356 causes the Q output terminal of the flip-flop 334 to go false. This false signal is also applied to the NAND 326 and the EOR 358. A false signal applled to NAND 3~6 keeps the false-actuated EOR
328 rom pasting clock pulses Jo the counter 330 while the counter is counting down. A false signal appIied to the OR 358 allows the EOR 328 to pass encoder pulses to toe counter 330 rather than clock pulses.
Thus, when the direction of the counter 330 it changed so that the counter 330 counts down, the counter 330 no longer counts clock pulses but encoder pulses. When the number of encoder pulses counted down equals the number ox clock pulses counted up, the carry-out pin (pin 7) ox the counter 330 causes a gignal to be applied to the clock terminal of the slip 10p ~42 so the Çalse signal appearing at the ~D~ pun i9 clocked through the fllp-10p 342 and a false signal appears at the output terminal. false signal at the Q output terminal of the fllp-flop 342 deactivate the jaw actuator 2~. Deactivation of the jaw actuator means that the plunger 92 is free to Hall downwardly, as does the linkage 30. Downward action of thy linkage 30 causes the second jaw member 26 to pivot about pivot pin 178 in a direction away from the first jaw member 3G 24~ The false signal at the Q output terrninal of flip-flop 342 also, when coupled with the false signal from the inverting driver 346, causes the compare signal (the output of the inverting driver 356) to again go true, thus enabling the clock 330 to start counting in 'J
~L~33 an up direction and enabling the EOR 328 to pass clock pul8es to the counter 330 rather than encoder pulses.
From the foregoing it is seen that an advantage of the invention is making thle time at whlch 5 the jaw actuator it selectively activatled and deac~iva~ed dependent upon the speed in con~unation with which the grlpper arm operate. A Rhown in Flg.
Another advantage ox the present invention is the provlsion of a gripper axm which is easily manufactured, in~talledt and removed for serviaeability reason.
Yet another advantage of the present l invention i5 the provision of a gripper arm which has few moving part, low mass, few lubrication poln~, and few point of frictlon and wear.
A further advantage of the present lnvention is the provision of a gripper arm wherein the coefflclent o friction between an insert and a jaw member it increased, thereby increaslng the force available to pull an insert from a hopper of a corresponding insert station but wlth less strain on the gripper arm.
Still another advantage of the present invention it the provision of a gripper arm having a movable jaw member which tightly grip inserts regardless of insert thickness Yet another advantage of the present invention is the provision of a gripper arm which, when installed in an insertion machine, facilitates easy acces3 to and around an invert track s~f the insertion machine .
SUMMARY
A gripper arm include3 jaw members between which articles are engaged and from which engaged articles are released in precise placement upon a transport means. Actuating means preferably in the form of solenoid means is used to selectively move a 3!i 5econd jaw member toward and away from a if jaw member in connectlon with the engagement and release 3Æ~3 operations. In view of the act that the actuating means mutt be activated for diferent lengths o time when the gripper arm it operated at d1f~ering peed in order to result in precise placement a,f an article upon the transport means, the timing of the activation of the actuating means 1R controlled to be dependent upon the operating speed of a machine in conjunction with which the gripper arm it used.
In the above regard, jaw actuator control means includes first sensor means or determining a machine cycle rate; second sensor means for determining when during each machine cycle the actuating means should be selectively enabled and disabled; and, meanR
fur determining a suitable machine cycle rate-dependent delay interval between the determlnation made by the econd sensor means and the actual selective enablement and disablement of the iaW actuating means. In a preferred embodiment, the delay determining means comprise an up/down counter enabled to count up pulses prom a clock1ng means and, when allowed to do so by the second 3ensor means, to count down pulses geneeated ln accordance with the second sensor mean.
In another embodiment a jaw member ha a piece of high coefficient of friction material embedded in a surface oriented to contact articles engaged between the jaws, BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and advantages of the inven~lon we 11 be apparent f rom the following more particular descript1On o the 5 preferred embodiment a illustrated in the accompanying drawing in whlch reference character refer to the same parts throughout the varlou~ view.
the drawing are not nece3~arily to scale, emphasis instead belng placed upon illustrating the prlnciples 10 of the invention.
FIG. 1 is a d{ agrammatical view of portion of an insertlon machine according to an embodiment of the inventlon;
FIG. lA is a rear view of a gripper arm according to an embodiment of the invention;
FIG. lB it a side view taken along the lone O of the gr$pper arm of ~19. lA;
. FIG 2 l an exploded view of the gripper arm of another emb~dlment o the invention;
FIG 3 is a cirault diagram showing actuator control mean3 according to an embodiment of the invention;
FIG. 4 is a graph showing various parameters as functions of machine cycles when a machine is operating at 4t500 cycles per hour;
FIG. 5 is a graph showing various parameter a function of machine cycle3 when a machine 1 operating at 10~000 cycles per hour;
FIGS. 6A and 6B are rear and side vlews, respectively, of a Hall Effect device according to an embodlment of the invention;
IGS. 7A and 7B are front and side views respectively, of magnetic mean according to an embodiment of the inventlon;
~233~
FIG. 8 is an illustrative b1ock diagram of mistake cletector fc)r a plurality of griLpper arm according to an embodiment of the inventiorl;
FIG. 8A is a schematic dlagram depicting 5 electrical circuitry included in the mistake detector of Fig. 8;
F IG . 9 i s a g r aph how i ng ou tpu t vol tag e f rom a Hall Efe~t ~en~or as a junction of insert thickness according to an embodiment of the invention FIG. 10 it a schema~cic diagram depicting the relationship of jaw members and magnetic means relative to a p1vot point;
FIG. 11 is a detailed view of a portion of the gripper arm of Fig. lA;
FIG. 12A is a detailed rear view o a portlon of the gripper arm of Fog. lA;
FIG. 12B is a detailed view of a portion of the gripper arm of Fig. 12A cut along the line ED";
FIG. 13 it a wide sectional vlew showing first sensor means and second sensor means mounted in relation~h~p to main drive hat means;
FIG, 14 it an end view of an actuator timing disc included in a second tensor means; and, FIG. 15 it a graph showing solenoid force requirements and spring force requirements as functions both of solenoid and upper jaw member positions according to an embodiment ox the invention.
DETAILED DESCRIPTION OF THE DR~INGS
Referring to Fig. 1, there is shown an insertion machine 10 which collects a plurality of inert into a pile and transport what pile to an inverting station IS; conveya an open envelope to inserting station IS; and, then insert3 the pile of lnserts into the envelope. Turing steps unillustrated ~'J
~3~3 .
~6--in Fig. 1 the insertion machine 10 later seal the envelope and pro~e~e~ the envelope or malling. It wlll be appreclated that the operation ox machine 10 ls timed in accordance with a machlne cycle. In this respect, an indlvidual envelope require several machine cycles to be processed. With the exception of a few initlal or start-up machlne cycle, a pile of inserts it inverted into an awalting corresponding envelope at the end ox each machine cy¢le.
In order for insertlon machlne 10 to collect a pile of insert at inverting 3tation IS, there ar,e provided therein a plurality of insert stack stations or hoppers Sly S2, and S3 and a plurallty of corresponding gripper arms 161, 162, and 163 each mounted to a shaft 17 which extends over an insert raceway 18. Insert statlon Sl, gripper arm 161, and shaft 17 serve to wlthdraw one insert from the tack ox insert and drop that in~er~ onto'raceway 18r More particularly, invert station Sl holds a tack of inserts Il on a manner whereby the bottommost invert i8 separable from the rest of the tack Gripper arm 161 is connected to shaft 17 which oscillates once during a portion of each machine cycle in order to rotate arm 161 toward and away from the tack of inserts While rotating toward the stack5 the jaws of gripper arm 16 are opened to allow the art to engage the bottQmmost insert When the shaft 17 stops moving arm 161 toward the stack, the jaws are closed to engage the bot0mmo3t insert. Shaft 17 then rotates gripper arm 161 away 3G rom the tack, thereby withdrawing the invert from the bottom of the stack. Gripper arm 161 then opens its jaws to release the insert which fall3 onto invert raceway 18. Thus, insert station 51; gripper arm 161, and shaft 17 cooperate to withdraw one lnsert from the tack and drop that insert onto raceway 18.
Insert raceway 18 include a pIurallty of palrs ox pusher pins P which are mounted on a palr of chalns snot shown) whlch are perlodlcally drlven by machine 10. The chains are drlven once during a portion of each machine cycle and move the pusher pins P to the next lnser~ stat;on. Ater the ju~t-described dropping of an insert from station Sl onto raceway 18, for example, pin P push the insert to the vicinity of the lnsert talon S2 and top.
In view of the foregoing, it wlll be teen that invert ~tation~Sl, gripper arm 161, shalt 17, and raceway 18 cooperate to withdraw one insert from the stack and convey that in ert to station S2. It will be appreciated that for the embodiment 3hown one insert from station Sl is conveyed to statlon S2 each machine cycle.
Insert station S2, grlpper arm 162, and shaft 17 cooperate in a similar manner insert ~tatiun Sl, gripper arm 161, and shaft 17 and serve to withdraw one 2~ invert from the stack o inserts at talon S2 and drop that insert onto raceway 18~ More particularly, insert stack station So holds a stack of inserts I2 in manner whereby the bottommost insert is separable from the rest of the ~tackO Gripper arm 162, which is also connected to oscillating shaft 17, rotates toward the bottommo~ insert; grab that insert; rotates away from the stack; and, then releases the lnsert. This insert fall ontb insert raceway 18 which already contains an insert Il. Pusher pins P of raceway 18 advance this pile to the next insert station. thus, during another machine cycle, invert station S2, gripper arm 162, shaft 17, and raceway l cooperate to add an insert I2 to insert Il and convey the pile to station S3.
Invert station S3, gripper arm 163, and shaft 17 cooperate in a similar manner as insert station 51 --8~
and S2, grlpper arm 16~ and 162, and shaft 17 and verve to wlthdraw one insert from the tack o 1nserts at stat10n S3 and drop thaw inert onto raceway l Invert stack station S3 separates the bottommo~t invert rom the rest of a tack of inverts I3. Gripper arm 163 rotate Howard the bottommost inse!rt; grabs that insert; rotate3 away from the stacks and, releases the lnsert onto inserts Il and ~2 on raceway lB. This thereby completes the pile of inserts. ~acsway 18 then conveys the completed pile Jo inserting statlon IS.
Thus, during a thLrd machine cycle inert 3tation S3, gripper arms 163, shaft 17, and raceway 18 cooperate to add an invert I3 to a pile of insert and convey 'che pile to inserting station IS.
In view ox the foregoing, it will be seen that insert stack stations Sl, S2, and S3, respective gripper arm 161, 162, and 163, and insert raceway lB
cooperate to collect a pile of hefts and convey that pile to nserting station IS in three machine cycle .
A mentioned above, insertion machine 10 convey an open envelope to inverting station IS. To this end there are provided an envelope tack ~atlon ES; an envelope flap opening ~tatlon ~0; a flap hold down bar 19; and, an envelope raceway 21~ Envelope stack statlon ES holds a stack of envelopes; separates the bottommo~t envelope from the rest of the stack;
and, feeds the envelope to a clamp C in envelope raceway 21. Envelope raceway 21 includes clamp C which is mounted on a chain snot shown) which is periodically drlven by machine 10. The chain iB driven once during a portion oE each machine cycle and moves the envelope to an enYelope flap opening station EO. At station EO, a sucker cup (not shown) rotates toward the closed flap of an envelope, applies a vacuum to the flap and rotates away f rom the envelope in order to open the ~33~3 _9_ flap ox the envelope. The raceway 21 then moves the envelope to the inserting sta~1on IS while the flap of the envelope ls held down by bar 190 When an envelope and a pile o inserts are at inserting station IS, insertion machine 10 inserts the pile of 1nserts into the opened envelope. .To this end, there are provided in machlne 10, a pusher arm PA and a vacuum bar VB. The vacuum bar VB lifts up the back (top) wide of the envelope end shaft 17 rotates and thereby moves pusher arm PA toward tha opened envelope As a result, the pile of inverts will be pushed ho the envelope. Thua, pusher arm PA and vacuum bar VB cooperate to invert a pile ox inverts into an opened envelope at inserting station IS, although Fig. 1 shows an insertion machine with three insert stack stations Sl, S2, and S3, it should ye understood that the number of lnsert stack stations 13 not critical Jo the prevent 1nven~ion and what In other embodiments fewer or more such invert station are employed along a suitable raceway.
A discussed hereinbefore, during the operation ox machine 10 it i8 highly d~irable to provide an indication when one of the gripper arms grips too few or too many inserts. Insertion machine 10 includes an improved double/miss detector which is relatively easy to calibrate and adjust and which is described in detail below.
In additionJ it should be appreciated that it is desirable to provide a reliable gripper armO
Insertion machlne 10 includes a reliable gripper arm which will now be described.
~L~3;~ 3 GRIPPER ARM MECHANICAL STRUCTURE
Each grlpper arm 16 according to an embodiment of the invention includes a houslng 20;
securing means 22 for securiny the grlpper arm to osclllating drlve means such as heft 17~ A fist article-contacting or jaw member 24; a second article-contacting or jaw member 26S jaw actuation means, suGh as solenoLd actuation mean 28; and, linkage means 30. Flgs. lA and lB (as well as Figs. 11, 12A, end 12~) show a gripper arm ac¢ord~ng to one embodiment of the inventivn while Fig. 2 shows a gripper arm of a second embodiment which is generally similar Jo the embodiment of Figs. l but which includes different structure for ~t3 linkage means. Structural element common to the embodiment of Fig. lA and lB and Fig 2 ar¢ assigned the tame reference numeral3 for description purpose3 hereinafter.' Gripper arm housing 20 has a distal end 32 and a proxlmal end 34. The means 22 for securing the gripper arm to the oscillating drive shaft 17 include (l) a aemi-cylindrlcal recess 3~ at the top of the proximal end 34 of the gripper arm housing 20, and (2) a clamp member 3B. The recess surface 36 is contlguou~
with flanges 40 on either s$de o the recess 36~ The flanges are generally parallel to the major cylindrical axis of the recess 36. The clamp member 38 mates with the proxlmal end 34 of the housing 20. The clamp 38 it formed with comparable flanges 42 which mate with the flanges 40 of housing 20. The clamp 38 has a cylindrical sector portion 44 which forms a semi-cylindrical recess 46. Each ox the 1anges 40 and 42 have two threaded apertures thereln appropriately aligned to receive threaded fasteners 48. In this respect, flanges 40 have aperture 50 and flange 42 ~3~ 3 have aperture3 52. The fa~ener~ 4~ secure clamp 38 to the proximal end 34 of the housing 20 so that the gripper arm is clamped onto the oscillating drive shaft 17. Each threaded fastener 48 extends through the aligned aperture 50,52 and the housing flange 40 and the clamp flange 4~, respectlvely.
The gripper arm housing 20 comprises opposing side panels 54 which extend the helght 5f the gripper arm. The two side panel 54 define a space therebetween. At the proximal end 34 of the gripper arm housing 20 the wide panels 54 are parallel and separated by a distance A as shown ln Fig. lA. it the mid-section o the gripper arm hou~i~g the slde panels 54 begin to converge to one another but separate beore dolng so and continue in parallel manner to the do stal end 34 o the housing 20. A thy distal end ox the housing the 3ide panel 54 are spaced apart at a dl~tanc:e B whlch i le3~3 than distance A a shown in Fig . lay, .
In the region where the wide panel 54 are separated by the distance A, a fronk panel 56 it integral with the wide panels 54. In this region where the wide panel 54 are separated by the dis'cance A, each side panel 54 has at its back a perpendicularly extending flange 58. Each flange 58 has two threaded aperture 60 therethrough, as well a3 a vertically extending channel 6~ at the intersection of the plane which includes the lnterior surface of the hou~ing-side panel 54 and the plane which includes the flange 58.
The gripper arm housing 20 also includes a backplate 64 which has a back member 66 and a base member 68 perpendlcular thereto The back member 66 has four aperture 70. Two of the apertures 70 are on each side of the back member 66, each aperture 70 being aligned with apertures 60 on the ~id0 panel flanges 58 ~33~
when the back member is a sembled to housing 20.
Threaded fastener 72 extend through the aperture 70 of backplate 64 and through the aperture 60 o the side panel flange 58 to aecurs the backplate 64 to the geipper arm housing 20. The base member 68 ox the backplate 64 is adapted for placement between the side panels 54 in an area where the 3ide panels begin Jo ¢onverge~
As described above, the side panels 54, front plate 56, back member surface 56, and backplate base member 58 generally refine a hollow volume 74. Volume 74 ls not totally confined, however, inasmuch as the base member 68 of the backplate 64 ha an aperture 76 thereon and the height of the back member 66 of backplate 64 $~ such as to leave an essentially rectangular gap 78 above the backplate 64.
Volume 54 houses the jaw actuatiny meana which, ln the illustrated embodlmént; it solenoid means 28. The solenoid mean 28 has an essentially 2~ cylindrical casing 80. Solenoid cawing 80 has a mounting plate 82 secured thereto. In the embodlment shown, the mounting plate 82 has protrusions 84 thereon adapted to fit into the channel 62 of the side panel flanges 58. As shown in Fig. 2, electrical leads 86 extend from the interior ox the solenoid casing 80 and are included in a ribbon-type cable 907 Although not shown a5 such ln Flg. lA, it should be underskood that the ribbon cable 90 extends from the volume 74 out through the rectangular gap 78 on the back of the tripper arm and is connected Jo appropriate circuitry including the type of circuit shown in Fig. 3, the circuitry to which the ribbon cable 90 l connected resides on a circuit board or the like situated elsewhere on the particuiar machine in conjunctlon with which the gripper arm of the invention operatesO
33~3 Toe ~oleno~d mean 28 alto compr1se~ a plunger means 92. Near it bate plunger mean 92 ha an annular groove about which C-clamp rleta1ner 96 f lt~o the lower end o the plunger 92 'ha a slot 98 S therein through the diameter o the plunger 92. The plunger 92 alto has an aperture 100 extending therethrough along a diameter of the plunger 92 which is transverse to the slot 98. The plunger aperture :L00 it adapted to receive a rollpin 102.
Turning now to the embodlment of Fig. 2, the llnkage mean 30' comprises a biasing means and a connecting rod 120. The biasing means includes a cylindrically coiled inner spring or extension sprung 12?. having coils formed generally in planes perpendicular to the major axis of the cylinder. The ~nnee ping 122 has flr~t and second ends formed in ~ing-llke fashion, the end ring being formed ln plane ln which the axis of the cylinder lie (that iB, the planes of the end rings are generally perpendlcular to the planes of the coil included on inner spring 122~. Ring 124 at the upper end of the inner spring 122 is adapted to receive pin 102 therethrough when the ring 124 it inserted into the slot 98 of the plunger 92. Ring 126 at the lower end of the inner spring 122 i8 adapted to receive a pln 128. Lower ring 126 receives pin 128 whey the lower ring 126 is inverted into a tran~ver~e slot 130 formed in a irst end of end cap 132. End cap 132 has an aperture 134 through the diameter whereof which intersect the lo 130 ln perpendicular ~a~hion in a manner similar to the slot 98 on apertures 100 ox the plunger 92.
End cap 132 has an annular shoulder 136 near its mid3ection BO that an outer pring 13~ can be confined between the shoulder 136 and the base member 68 of the backplate 64. Thus, the outer ~prlng 138 ls ~L~33~
ox greater diameter hart toe inner spring 122 and fits ln concentric Eashion over the inner sprlng 122. the outer spring 138, according to one mode of the lnven~ion, preloads the inner expansion spring 122 by S stretching spring 122 a desired distance 50 that spring 122 cause jaw 26 to exert a force of a desired magnitude on insets engaged between jaws 24 and 26.
A further seen in Fig. 2, the lower end ox the end cap 13~ receives a threaded top 1~0 of the connecting rod 120. The connecting rod 120 extends between planes ln which the do panel 54 are lncluded downwardly toward the distal end 32 o the housing 20. The rod crooks outwardly to the side at polnt 142 as it extends downwardlyl and when bend inwardly to have a por~lon 144 in horizontal orientation at the lowest extent of its travel. the lower end 144 of the rod is adapted to receive a lock member, such as C-clamp retainer 146.
The dial end 32 of the gripper arm housing 30 has, in the Fog. 2 embodiment shown, a first jaw member 24 which i6 formed lntegral with the housing 20 a a lower jaw member. A rectangular recess 160 ig Çormed in a surface of the jaw 24 which is oriented to contact an article to be engaged by the gripper arm.
rrhe recess 160 is adapted to receive a piece of high coeficient of friction material, such as a piece of urethane 162.
The second jaw member 26 as shown in Fig. 2 comprises a block 170 insertable in a space defined by the separated lower ends of the side panel 54. The block 170 has a protruding curved member 172 extendlng therefrom, the underneath surface of which contacts article to be engaged by the grlpper arm. Block 170 also has two aperture 174 and 1~6 extending therethrough. The aperture 174 l adapted to receive a ~%33~
-lS-pivot pln 17B so that the second jaw member 26 can pivot about the pln 17~. rrhe 0econd aperture 176 it adapted to receive the horizontally extending lower end portion 144 of the connectins rod 122.
The pivot pin 17~ i5 received not only through aperture 174 in the jaw member 26, but also through aligned apertures 180 ln the distal end of the slde panels 54. Thus, when the seaond jaw member 26 is lnserted in the space between the side panel 5~ near lQ the dl~tal end 3~ of the gripper arm houzing 20, the aperture 174 and 180 are aligned BO that the pivot pln 178 can freely fit therethrough. The plvot pin 178 it retained in position by a set screw 181 so that the plot pin 178 rotates in bearing-like end cap5 182.
lS The embodiment of Figs. lA and lB differs tightly from the embodiment of Flg. 2, ln the configuratlon of the partlcular linkage means utilizedO Whlle the embodiment of Figs. lA and lBj like that o Fig. 2, ha an inner spring 122, the inner spring 122 of the embodlment of Fig. lA and lB i5 positioned ln a cylindrical spacer or sousing 202. As ¦ in the Fig. 2 embodlment, the upper ring 124 of the l inner sprlng 122 it secured by plunger pin 102 to the I solenoid plunger ~2. The top of the cylindrical 251 housing 202 abuts the lower end of the plunger 92.
! The lower end of cylindrical houslng 202 abuts a retaining rung 203. The re~alning ring 203 is carrled ln an annular rece 5 on a clevis-type end cap 204. The pin 128 extends radially through the end cap 20~ in a manner understood from the description of the end cap 132 of Flg. 2. End cap 204 axially receive a ; pin 205 which has an upper exterlor portion thereof ! threaded or engagement in an axial aperture of end cap 1 204. An upper end o a cable 206 is connected to the 35 1 lower end of pin 205. Cable 206 extends rom the pin 'I
205 to the distal end 32 of the grlpper jAW. At it lower end the table 206 ha a ball 208 fixedly attached thereto.
Located in the cylindrical housing 202 in the manner described above, the inner spring 12~ of Flgs.
lA and lB i3 held so that it it generally extended about D.25 inches beyond i~B length a rest. The spring 122 is thua preloaded to h~Ye a desired sprung force For the embodiment of Fig. lA and lB and 11, the upper jaw member 26 comprlses a block member 210 and a curved protrusion 212. The underside of the protrusion l used to contact articles engaged by the gripper arm. The block member 210 ha a narrow slit 214 at the back thereof through which the lower portion ox cable 20~ extends. At the bate of the slit 214 it an essentially square chamber ~15. Chamber 215 hove ball 2n80 When cable 206 pulled upwardly the ball 208 thereon, having a greater d~ama~er than the wLdth of the slit 214, bears agalnst the top interlor surace of the chamber 215, causing the upper jaw member 26 to pivot 50 that the upper jaw member 26 approaches the lower jaw member 24 Jo that the jaw esqent~ally closes.
The block member 210 of second jaw 26 also has three apertures 216, 218, and 220 extending therethrough. The central aperture aperture 218) accommodates a pivot pin 222 about which the jaw member 26 pivot.
The embodlment of Fig. lA and lB and 11 further comprises means or biasing the jaw member in an open posi~icnO The biasing means includes torsion spring 230 (seen in Figs. 12A and 12B). An intermediate portion of the torsion spring 230 has a helical shape whlch is concentric wlth and its over on ~;23~3 exposed end of plvot pln 222, the end olE pln 222 protruding beyond a side panel (the left ode panel a seen on Fog. 12~) of the gripper arm. A it exposed, protruding end the pivot pin ~22 has a head 232 formed thereonO A disc 234 is secured on the plvot pin 222 just inside its head 232. The helical portlon of the torsion spring extend between the disc 234 and the left side panel oP the gripper arm, A one ox it end the torsion spring 230 departs from it8 helical configuration and a~Rumes a linear shape as it extencls upwardly to a retaining pin 236 against a side of which it bear (Lee jig. 12~). At it other end the torslon spring 230 extend through a square notch 238 formed on the circumference of the disc 234. The portion of the torsion spring 230 that extend through the disc 234 bears against a corner 2~0 of the notch 238. Spring 230 bears against corner 240 to exert a biasing force on the disc 234 and the pivot pin 222 whereby the upper jaw member 26 i8 normally held open in the absence ox application of tension to the cable 206. When cable 206 and ball 208 thereon are urged upwardly, however, ball 208 bears against the upper interior surface of the chamber 215 and exert a force on block 210 which overcome3 the biasing force of the torsion spring 230 so that block 210 pivots about pin 22~, thus causing jaw 26 to clove.
GRIPPE A~M-ASSOCIATED
OPTO/ELECTRICAL STRUCTURE
Fig. 3 shows circuitry utilized in connection with the gripper jaw actuating control mean3 according to an embodiment of the invention. An encoder disc 260 and an actuator timlng disc 262 are mounted to rotat2 on a main drive shaft 263 of a machlne, such a an ~3~ 3 lnsertlon machinel in connection w1th which the gripper arm 16 of the inventiorl operates. The maln drive ~haf t rotate once per machine cycle and ha various tlming and drive means rigidly coupled thereto for power tran~mi3slon, quch a the aforementioned 03cillating driva mean 17, or example. The encoder disc 260 is a 64-tooth disc. The actuator timlng disc 262 ha us clrcumference configured to allow the passage o light (in a direction perpendicular to the plane ox the disc) about a disc central angle 266 corresponding to portion3 of a machine cycle during which the actuation means of the gripper arm it to be actuated 50 that the second jaw it either in contacting relation with the ~ir~t jaw or ha an article gripped between the first jaw and the second jaw.
Fig. 3 shows an encoder disc sensor 300 including the above-mentioned encoder disc 260 positioned to cause pa~age ox light from an LED 302 to be periodically incldent on circumferential teeth of the encoder dl c. If the light from TED 302 impinge on a tooth of the dlsc, then the light it not transmitted to receiver 304. If 2 circumferentlal space between the teeth on the encoder dlsc it allgned with a beam of light from LED 302, then the receiver 304 detect the light. An actuator timing disc sensor 306 also includes the above-mentioned actuator timing di c 262 with an ED 308 and a photoreceiver 310 similarly arranged about the ackuator timing dlsc.
The opto-interrupt receiver 304 it connected to two inverting drivers 312,314 in serles with one another. The output ox thé inverting driver 314 it connected to both input terminals vf a N~ND 316, the output ox which it connected to both i nput termlnals of a second NAND 318. The output of NAND 318 ig connected to two other NAND~ ~NAND~ 320 and 322).
I' i ~3~3 The clrculk of Fig. 3 also includes a clock or timer 324 having its clock output pin spin 3) connected to a ~ir~t input of a NAND 326. The NAND3 320 and 326 have their output terminals ¢onnected to respective input terminals of a fal~e-actuated 0~ gate 328. The output terminal ox OR gate 328 is connected to a clock input pin (pin 15) ox a delay determination means, such ag a pre~ettable up/down binary counter 33~.
.~ Up/down counter 330 ha its reset input pin connected to an output terminal and an EON gate 332.
One input of the EOR 332 is connected to ~12 volts; the other input terminal it connected to the output of RAND
3~2~
i5 The up/down directlon pin spin 10) o the counter 330 i3 connected to the Q output of a "Do Ellp-flop 3340 The set and reqet input pin3 of the flip-slop 334 are grounded. The "D" or data input pin of the fllp-~lop 334 is connected to a compare signal in the manner hereinafter described The clock input pln spin 11) of the flip-10p 334 i8 connected to the output of NAND 318.
The data input pin (pins 4, 12, 13d end 3) and pin 5 of counter 330 are grounded. Output pins 6 and 14 of the counter 330 are connected to respective input terminal of a NAND 336. The output terminal of NAND 336 Lo connected to the reset terminal (pin 4) of k timer 324~
The carry~out terminal (pin 7~ of counter 330 is connected to a first input terminal ox a NAND 338.
The second input terminal of NAND 33B it connected to an appropriate voltage eor setting initial condition for machine start-up. The output of NAND 338 it connected to a first input kerminal of an EOR 340, the other input terminal of the EOR 340 being connected to I? V
~L233~3 a ~l2 volt3~ The output ox the EOR 340 18 connected to a clock lnput pin (pin 3) o a "DN flip-flop 342, Flip-lop 342 ha its reset and jet ~erminal3 spins 4 and 6, respectively) connected to ground. Thy "Do or data terminal it connected to thlo output of inverting driver 344 and 346 which are connected in series between the receiver 310 and the fllp-flop 3~2. The Q output terminal spin l) of the flip-flop 342 it connected both to the first input terminal of an EOR gate 350 and to two inverting drivers 352 and 354 ln cries The other input termlnal of the Eon 35D Ls connected through the in~ertlng driver 344 and 346 to the re¢eiver 310 o the actuator timing do 306.
The output terminal of the EOR 350 is connected to an inverting driver 356~ The outpu termlnal of the inverting driver is in turn connected both to the data input pin spin 9) of flip~flop 334 and to the second input terminal of NAND 322.
The Q output terminal of slip flop 334 it alto connected both to the second input terminal of NAND 326 and to a f$rst input terminal o an EOR gate 358. the other input termlnal of toe EOR gate 358 it connected Jo +12 volts. the output terminal of the EQR
gate 358 is connected to thy second lnput terminal of In the illustrated embodiment, NAN~s 316, 318, 320, 322, 326, 336, 338, and false-activated OR
328 are included in a single integrated circuit chip such as a QUAD-2 Input NAND Schmitt Trigger. Counter 330 it a presettable up/down binary counter. EOR gate 332t 340, 350, and 358 are included in a quad Exclusive OR gate. Flip-flop~ 334 and 342 are lncluded in a Dual "D" Fl~p-Flop Chip. Clock 324 is a linear timer.
Inverter driver 312, 314, 344, 346, 352, 354, and 356 are included ln a 7-channel PMOS Input Driver.
~21 For the embodiment of Flg. 3, by way ox example, re~3istance values are g1ven Jo the resistors and capacitance values are given to the capacLtance~ aa shown on l:he hollowing chart:
RES I STANCES
Rl = R2 - R3 = R4 = lK
:~5 5K variable) ~6 R7 8 ~8 - 1. 2R
R9 ye R10 lûOK
Rll R12'~ ~13 - R14 = 10 R15 = 470 Ohm CAPACITANCES
Cl 0.1 F
C2 = 0.001 F
C3 1.0 C4 0~47 F
~5 - 0.01 MIgTAKE DETECTOR
A mentioned above, lnsertion machine 10 includes an improved double~mi~ mistake detector.
This double/miss detector indicates when owe of gripper arms 161, 162, or 163 qrip too ew or too many in~ertsO More particularly, a3 shown in Fig 8, there is provided a double/miss detector for each ox the gripper arms i.e., a detector 364/ 374, and 384 for lndicating when gripper arms 161, 162, and 163, respectively, grip the wrong number o inserts. Since detectors 364, 374, and 384 are substantially imilar, only detector 364 will be described in detail and it will be understood that detectors 374 and 384 wlll operate in a similar manner under simllar conditions.
~23~ L3 Detector 354 serves to detect when grlpper jaw 161 ha gripped too few or too many inserts. To this end, there are provided in deteatoL 364, a jaw displacement tensing means 366 and a mi.stake 1ndicating circuit 365. Jaw dlsp1acement sensing means 366 it mounted on the gripper ~aw~ ox arm 161 a hereinafter descrlbed and serve to generate an e1e!ctrica1 signal propor~lonal to the relative d~sp1acem~nt between the grlpper jaw. When a proper number of inserts aye known to be gripped between the gripperljaw~, a witch is closed and a Bet pu1se 1B provided to mistake indicating circuit 365 which then serves to convert the electrical signal proportional to jaw displacement to a stored reference slgna1. ThiB stored reference signal is u6ed by indicating circuit 365 during a preselected time ox a machine cycle to determine if thy electrical signal generated by ~en~ing device 366 is wlthin predetermined 1imits.
It will be appreciated that the jaws of the gripper arm are forced open prior to grabbing the insert and the jaws are forced open in order to release the in3ert~ Since Sensing means 366 continuously generates an electrlcal signal proportional to jaw displacement, it is desirable to indicate a mistake condition only during the portion of the machine cycle when the gripper jaws are holding the insert, i.e., when the inserts are being pulled from the tack. In the present embodiment, a timing signa1 is applied to indicating circuit 365 shortly after the gripper arm 30 has pulled the insert from the stack and circuit 365 indicates a mistake condition only during this enabling signal. Thus, although sensing means 366 continuously yenerates an electrical signal proportional to jaw displacement indicating circuit 365 indicates a mistake condition only when the jaws are displaced by the inserts.
To the end that mistake indicating circuit 365 may swore a reference slgnal and indicate when a proper number ox documents is not grlpped by the gripper jaws, there are provided in indicator 365, a signal generating means 367; a comparing means 368; a storing means 369; a transmission gate 370; and, a mistake ind1cator/alarm means 372. signal generating 10 jeans 367 l connected to ~en~ing means 366 and generate three electrical signals which are proportional to the signal generated by sensiny means 366. The first signal generated is proportional to the signal generated by sensing means 366 and is applled to a input of storing means 3690 The second signal generated it a 1xed percentage greater than the flr~t eignal and correspond to the lower llmit oÇ acceptable jaw displacement. the thlrd 3ignal generated i5 a fixed percentage less than the ir~t 3~gnal and corresponds to the upper limit o acceptable jaw displacement. Storing jeans 369 tore the first electrical signal from generating mean 367 during the detector set-up or calibration time and thereafter applies that stored reference to comparing mean 368.
Comparing mean 368 compares the second and third signals from generating means 367 with the stored reference slgnal from storing means 369 and generate a first electrical signal when the results ox the comparison indicate that too few inserts have been grabbed by the gripper jaw and a second electrical signal when the results of the comparison indicate that too many inserts have been grabbed by the gripper jaw. The results o comparing means 368 are applied to the input o a transmission gate 370 which Q~
~33~3 provides a mistake indicatis:n only after the gripper jaw pulls the invert from the tack.
MIST~E DETE:CT0~ SENS0~ STRUCTURE
Figs. 6A and 6B show a sensor means 400 5 which, as shown in Figs. lA and lB, is mounted near khe distal end 32 of the gripper arm 16. The sensor means 400 it included in the jaw dlsplace~en~ sensing means such as ~en~ing mean 366 of Fig 8. The sensor mean 40û include a housing block 402 havlng a rectangular channel 404 wormed on its front surface. The rectangular channel qO4 has only one edge 406 thereof extending to an edge of the housing block 402~ rrwo fastener 40B having their shats flush wlth the channel 40~ extend through the housing block 402 to secure the sen or means 400 to the gripper arm in the location depicted in Fix. lA and lB.
The Yen~or mean ~00 further include3 a aover plats 410 which as teen in the rear view of Fog. 6A has rectangular dlmen~ion~ comparable to the front rectangular dimensions of the houslng block 402. The cover plate 410 i6 secured onto the housing block 402 by an epoxy adhesive material. A sensor element 412 ls accommodated in the rectangular cavity defined by the housing block 402 and the cover plate 410. Sensor element 412 serves to sense the flux density of a .
generated field and generates an output signal proportional thereto. In one embod1ment the sensor element 412 comprises a current-carrylng electrical conductor across which a voltage is generated when the conductor it in a magnetic fîeld, the magnitude of the generated voltage being proportional to the magnetic field flux intensity. on example o this embod.~ment of sensor element 412 is a Hall Effect sensor element.
! `J
cable 413 comprislng three leads 414, 416, and 41B
extends from the sensoe element 412 to the circult of Fig. 8A as hereinafter described.
Figs. 7A and 7B show a magnetic means 420 which is included in the jaw displacement senslng mean ~uah as mean 366 and which cooperate with the senBor means 400. The magnetic means 420 includes two rare earth magnets 422 and 424, each being essentially disc shaped. Each disc-shaped magnet 422,424 is mounted in corresponding circular aperture formed in a disc-shaped holder 426 having a dlameter at least greater than the sum of the diameter of the magnets A seen in Fig. 7A, magnet 422 has it North pole exposed while magnet 424 ha lts South pole exposed. The clrcumerences of the two disc-~haped magnets come clo3e to touching on a line 428 which connects their centers.
The magnet holder 426 it further mounted on a mountlng bracket 430. Mounting bracket 430 is a thln sheet of a re~llient metal such a Spring Temper Bra. Bracket 430 it bent along a line 432 which ~epara~e an upper beacke~ portion from a lower bracket portion. In its natural state (i.e., not installed in the gripper arm 80 that no external mechanical forcez are acting on the upper portion of the bracket 430), the upper bracket portion bends away from the lower bracket portion at an angle alpha which is approx1mately 15 degrees. The upper bracket portion has the magnet holder 426 mounted therein. The lower bracket portion has three apertures extending therethrough. A central aperture 434 i9 sized to accommodate the pin 222 which functions as the pivot point about which the second jaw member pivot with respect to the first jaw member. The central aperture 434 is po~ltioned so that an imaginary line 436 3~3 --2~--extending through the diameter ox aperture 434 and con~truc~ed perpendicular to line ~28 intersect line 428 midway between the centers of magnet:s 422 and 424. The point of lntersection of the lmaginary line 436 and the llne 428 bisected thereby it; taken us the center of the magnetic f ield and labeled as point X it the drawing. Apertures 438 on either side of central aperture 434 are adapted to receive fastener3 440 which, as seen in Fig. lA, secure the magnet means 420 and particularly mounting bracket 430 of the imaginary line 436 and the lint 428 blsected whereby i8 taken as the center of the magnetic field and labeled as point:
on the drawing Apertures 438 on either slde of central aperture 434 are adapted to receive fastener }S 440 which, as seen in Flg. lA, secure the magnet meanY
420 and particularly mounting bracket 430 thereof to the second jaw means 26.
As shown in FigO lB, thé màgnetic means 420 i3 sandwiched between a gripper arm side panel on itB
one ~lde and the Be~SOr mean zoo on the other gripper arm ~lde panel on its other side. In order to be hela in the position shown in Fig. lB the resllient bracket 430 must be deflected to an essentially planar configuration rather than the configuration of Fig. 7B
which shows a bending of the upper bracket portion about an angle alpha from the lower bracket portion.
When in the assembled configuration of Fig. lBJ it i8 to be understood that the spr~ng~like resilient biasing properties of the bracket 430'urge the e~senti~lly planar ace of the disc-shaped magnet holder 426 against the essentially planar cover plate 410 of the sensor 400. As seen hereinafter w1th respect to Fig.
lB, movement of the second jcaw member 26 about pivot point 222 causes the magnetic means 420 to slide across J
~3~
the sensor mean 400, thereby changing the magnetlc yield flux detected by the sensor element 412 MISTAKE DETECTOR CIRCVITRY
As mentioned above, cable 413 extending from s the sensor mean 400 includes the leads 414, 416, and 418 which are connected to the circuit of Fig. 8A, The circult of Fig. 8A is not located on the gripper arm it~l, but on a circuit board remote from the gripper arm.
As shown in Fix, 8A, leads 414 and 418 are connected to ~12 volt and round, re~pectlvely. read 416 iB connected to a node 450 of the slgnal generating means 367. Signal generating means 367 includes a voltage division network which comprises resistor Rl6, lS ~17 and Rl8. In the voltage division network a nod 451 occur between the connection of re~istor~ R16 and Rl7 and a node 452 occurs between the connection of resistors R17 and Rl8. Node 450 is connected by a capacitor C6 to ground.
The low side of resistor Rl~ (node 451) is connected by a lead 453 to storing means 369 illustrated as a sample and hold circuit, and particularly to a non-inverting input terminal of a llnear operatlonal amplifier 4S6 included thereln. The sample and hold circuit further comprise NAND gates 458 and 460; a 14-stage binary counter 462; and, an operational ampliier 464~ The inverting input terminal of the OP AMP 4S6 is connected both to the output terminal of the OP AMP 464 and through a resistor Rl9 to the inverting input terminal of the OP
UP 464. The output terminal of the OP AMP 456 is connected to a first input terminal of the NAN 45~
The second input terminal of the NAND 458 is connected ( 3~3 by resistor R20 and capacltor C7 in 3erles both to the output terminal of NAND 460 and Jo the clock input pin of the counter 462. The second input t:erminal of the NAND 45~ s also connected to both the output terminal of NAND 458 and to a first input termirlal of NAND 460 through resistors R20 and ~21. second input terminal of NAND 460 is connected through a leacl 46~ to a lead 468 and a selectlvely closable calibration switch 467. Lead ~68, which carries a clocklng signal, i connected to a reset pin ox the counter 462 through the calibratlon switch 4~7.
Output pin 1, 2, 4-7, and 12-15 of counter 462 are each connected by one of the resistors R22 to a voltage dlvislon network. The voltage division network comprises nine resistors R23 arranged in series, tha low side of each resistor connected (through a resistor R22) to a corresponding output pin of the counter 462 and the hlgh wide connected (through a resl~tor R22) to a neighboring output pin of the counter 462. Output 20. pin 2 ox the counter 462 is connected through its associated resistor R22 to the non-inverting input terminal of OP AMP 464 and through the resl~tor ~22 and capacitor C8 to ground.
The circuit of ~19~ 8A also illustrates ln more detail thy comparing means 368; the transmission gate 370; and the mistake indicator/alarm mean 372.
In this respect, the comparlson means 368 comprises both double" comparison means (such as operational amplifier 470) and Miss" comparison means such a operational amplifier 4~0). Similarly, the transmission gate 370 comprises a "double" mistake gate (including a multivibrator such a ~Dn-type Elip flop 472) and a Miss" mistake gate (including a similar multivibra~or 482). the indicator alarm mean 372 J `J
3~3 ?
-2~
includes lnverting drivers ~74 and ~4 and respective LED3 such a "double" hED 476 and "mi0~" LED 486, th respect to clrcuit elements used to detect a l'double", the nvn-lnverting input terminal o S the OP AMP 470 is connected Jo the low wide of resistor ~17 (node 452) while the inverting input terminal of OP
AMP 470 i 8 connected to the calibrated reference slgnal occurring at the output terminal of the OP AMP 464.
the output terminal of the OP AMP 470 is connected to the data input pin of the flip~1Op 472. The set terminal of the flip~flop 47Z 18 grounded, but lt termlnal l connected to the input terminal ox the inverting driver 474. The clock pin of flip-~lop 472 i8 ultimately connected to a lead 468 which carries a tlming pulse indicatlve of the point in tlme of a machine cycle when the flip-f.lop 472 i8 to transmit the comparison result to the indicator alarm means 372 to the point in time in whirh the separation of the gripper jaw member 24 and 26 is to b* detected. The reset pin o the flip-flop 472 is connected to a lead 477 which 3electively carries a reset pulse.
The output terminal o the driver 474 is connected (1) through a re~i~tor R24 Jo t24 volts D.C.;
(2) Jo the cathode of LED 476 and through resistor ~2 to ~24 volts D.C.; and, (3) to the cathode of a diode 478, the anode of which is connected to a lead 479 which carries a signal indicative of a detected mistake to unillustrated portions of the system which have need to know of the mistake.
With the exception of the input terminals of the OP AMP 483, the element 480, 482, 484, 486, and 488 used to detect a "miss" are connected in analogous manner with the elements 470, 472, 474, 476, and 478 as described above. however, the non-inv~r~ing lnput terminal of the OP ASP 480 it connected Jo the r 3~3 -3~
callbrated reference signal occurrlng at the output ~ermlnal of the OP AMP 464 while the inverting lnput term$nal of OP AMP 480 is connected to the node 450 ~th~ high side of ee~is~or R16).
For the embodiment of the elPctrical circuitry associated with the Hall ~f~c~ sensor 400 a3 shown in Fig. 8~, operational ampliflers ~56, 464, 470, and 480 are lncluded on a quad OP AMP chip; NAND gate3 458 and 460 are included on a quad 2-inpu~ NAND Schmltt 10 trlgger chip; and, flip-flops 472 and 4a2 are included on a Dual "D" flip-flop chip. The resistor and capacitor shown in the embodiment of Fig. 8A have the values shown on the following charts:
Resistors R16 - 100 ohm R17 - 100 ohm R18 = 4.7 K
Rl9 100 X
R21 = 10 K
R22 = 200 R23 = 100 X
R24 = 10 K
R25 = 1.8 R
R26 = 10 K
-Capacitors C6 = 1 microF
C7 = 0.003 microF
C8 - 500 pico~
OPERATION
The operation ox the gripper arm and the ~3~3 mistake detector are hereinafter described. the first general phase of operation de~aribed h~rein~fter i8 khe opening ox the gripper jaw such a takes place when an insert is released for dropping onto thle raceway 18.
5 The second general phase of operation dlescribed heeeinafter l$ the closing of the gripper jaws to engage anotber insert between the gripper jaw 50 as to pull the invert from its tack at thy insert ~tation~
The third general phase of operatlon described hereinafter l the operation o the mi~t~ke detector which determines whether the proper number of inverts are engaged between the cloyed gripper jaws.
For the most part the ensuing ~iscu~sion o the operation of the gripper arm and the mi take detector a~ume~ that the normal operatlons of the insertion machine are currently on-going and that inltializatLon or set-up of the insertion machine has already taken place. what is, k operation of the insertion mach$ne is descrlbed herein a being for the most part in the middle of a job. Where appropriate, however, operating ~ep~ or re3ults that have impact or pertain to machine set-up or calibratlon are also de~crlbed. In this respect; from Flg. 4 and portion of the ensuing discussion it is understood that the operation ox a slow jog mode such as used in machine jet up isO except for matter of timing, similar to the on-going operation. Also, following the description of the operation of the mistake detector the calibration operatlon of the mistake detector it also described.
GRIPPER JAW OPENING OPERATION
At an apprvpriate point in the machine cycle when the gripper jaws 24 and 26 are engaging an invert, light from the LED 302 o opto-interrupter ox encoder ~33~3 disc sensor 300 radiates through spaces between the teeth on the encoder disc qo as to be incident upon recelver 304, caving the recelver 304 to outpuk a true signal to the inverting driver 312. Inverting driver 312 inverts the true signal to a false signa} for appllcation to inverting driver 314. Invertlng driver 314 in turn inverts the false siynal to a true signal. When the teeth of the encoder disc interrupt the light between the LED 302 and the receiver 304, a false signal appears at the output of the inverting driver 314. Thus, a the encoder di3c rotates, a series of pulses is produced. In the series o encoder pulses generated by the 6~-tooth disc, the machlne man shaft rotates 5~625 of the machine cycle (5.6~5 DMC) between the leading edges ox consecutive true signalsO The graphs ox encoder pulse trains generated in this manner appear in Figs. 4 and 5, The encoder pulse train is applied to NAND 316 and 318 ox the -circuit shown in Fig. 3.
During operation the clock 324 is generatln~
clock pulses at a frequency determined by the manner in whlch the pin of the clock 324 are connected. When connected in the manner shown in Fig. 3 and de3cribed herein, the clock 324 generates pulses at a 178 rate. Trains ox pulses from the clock 324 are shown in Figs. 4 and SO Note that in Fig. 4 there are more clock pulses relatlve to the number ox encoding pulses than shown in Fig. 5. In Fig. 4I the machine is operating at 4,500 machine cycles (MC) per hour whereas in Fig. 5 the machine is approaching 10,000 MC.
The clock pulses from clock 324 are applled to the first input terminal of NAND 326. Whenever the second input terminal of the N~ND 326 is also true, a ealse signal is applied from the NAND 326 to the false-,1 ~33~
actuated OR gate 328. When the other input terminal of the false-aGtuated OR 328 i3 true, then pulses from the OR 328 are applied to the clock lnput pin of the prese~ta~le up/down counter 330.
Counter 330 counts up when pin 10 the directional pin) is true and counts down when the directional pin i3 ale The clock pulses of carry out pin 7 of the counter 330 are seen i.n Fig. 4 and 5. In relation to the clock pulses from clock 324, the fading edge of the output pulae~ prom the counter 330 oscur sub~tant1ally at the tame time the leading edge of clock pulseR from the clock 324.
cot pin 1 of the counter 330 it ultimately connected to the encoder disc ~ensar 300, so that the 15 reset pin of counter 330 receives a train of pulses the frequency of which is related to the number of machine cycles occuring per hour. The leading edge o a pulse in this encoder traln from the EON 332 causes the counter to be feet thereby termlna~lng the output pulse from the counter 330~ Thus, a seen in Fig. 4, when the machine i5 operating relatively 510wly at a rate of 4,500 MC per hour, the counter 330 can count up a greater number of clock pulses beore it is reset by the leading edge ox an encoded pulse from the EOR
332. In the graph of Fig. 5 on the other hand, the counter 330 has sufficient time only to count up one clock pulse before b ing reset.
The above descrlption of the operation assu~e~ that the actuator timing disc mounted on the 30 machine drive shaft is ln a position to permit the passage of light prom the LED 308 to the receiver 310. Under such circumstances the actuator is activated, and hence the 11nkage 30 causes the second jaw member 26 to be urged toward a contacting relationship with the first jaw member 24. The ~33~3 -3~-actuator timing disc has patterns on its circumference to obstruct the position of light from the LED 308 to the receiver 310 at points in the machine cycle in which It is desired for the second jaw 26 to open with respect to the jaw 24 as a result of the actuator activation. When this occurs, the absence Oe light at the receiver 310 causes output from the inverting driver 346 Jo go alse. This false signal is applied to the second input of the EOR 350. The first input terminals of the OR 350 still receive a true slgnal from the flip-flop 342 since no clock pulse has been applled to the flip-flop 342 to cause the flip~flop 342 to be effected by the false signal appearing at the ED"
pin (pin 5) of the flip-~lop 342. The true gnat from the Q output of the flip-flop 342 keep3 the solenoid drive at a true level meaning that the solenoid 28 18 activated and that the jaws 24,26 retain together Since the EON 350 now receives a true signal erom the flip-flop 342 and a false slgnal from the inverting drLver 346, the output of the EON 350 goes true. This true signal is inverted by the inverting driver 356 to be false. The false signal Erom the inverter 356 i5 seen in Figs. 4 and 5 as dropping to a false level in the portion of the graph labeled compare Output".
The false signal from the inverting driver 356 li.e. the "compare output" signal) is used in two ways. First, it is used to reverse the direction of the counting of the counter 330. In this regard, the 3~ false signal from inverter 356 l applled to the data input pin (pin 9) Oe the flip-flop 334 which causes the Q output pin to go false when the next enco.ler pulse s received at the clock input pLn oÇ the flip-flop 334.
The false output Oe flip-~lop 334 at the Q terminal causes the counter 330 to change direction that is, to ~33~3 count down). Second, the false signal from the inverting driver 356 is used to keep the EON 332 prom resetting the counter 334 while the counter 334 is counting down.
As mentioned above, the false signal from the inverting driver 356 causes the Q output terminal of the flip-flop 334 to go false. This false signal is also applied to the NAND 326 and the EOR 358. A false signal applled to NAND 3~6 keeps the false-actuated EOR
328 rom pasting clock pulses Jo the counter 330 while the counter is counting down. A false signal appIied to the OR 358 allows the EOR 328 to pass encoder pulses to toe counter 330 rather than clock pulses.
Thus, when the direction of the counter 330 it changed so that the counter 330 counts down, the counter 330 no longer counts clock pulses but encoder pulses. When the number of encoder pulses counted down equals the number ox clock pulses counted up, the carry-out pin (pin 7) ox the counter 330 causes a gignal to be applied to the clock terminal of the slip 10p ~42 so the Çalse signal appearing at the ~D~ pun i9 clocked through the fllp-10p 342 and a false signal appears at the output terminal. false signal at the Q output terminal of the fllp-flop 342 deactivate the jaw actuator 2~. Deactivation of the jaw actuator means that the plunger 92 is free to Hall downwardly, as does the linkage 30. Downward action of thy linkage 30 causes the second jaw member 26 to pivot about pivot pin 178 in a direction away from the first jaw member 3G 24~ The false signal at the Q output terrninal of flip-flop 342 also, when coupled with the false signal from the inverting driver 346, causes the compare signal (the output of the inverting driver 356) to again go true, thus enabling the clock 330 to start counting in 'J
~L~33 an up direction and enabling the EOR 328 to pass clock pul8es to the counter 330 rather than encoder pulses.
From the foregoing it is seen that an advantage of the invention is making thle time at whlch 5 the jaw actuator it selectively activatled and deac~iva~ed dependent upon the speed in con~unation with which the grlpper arm operate. A Rhown in Flg.
4, when the machine it operating at ~,500 MC per houry a delay of 15 DO occurs between an indication from the actuator timing disc that the actuator it to be deactivated and the actual deac~lvation. In F1g. 5 where the machine operates at 10,000 MC per hour, on the other hand, the delay is 7 DMC. Lets delay for deactivation of the actuator 1g required at higher machine operating speeds than lower machine operating speeds for the gripper arm to carry out operations that result in precise placement of an article engaged and released by a gripper arm. By making the ~lme o the deact1vation of the jaw actuator dependent upon the speed oE tha machlne, an operator can jet up a machine in a 810w jog mode for a gripper arm to depos1t an article a a precise location on tran~por~ mean with confidence that when the machine 1s operating at a higher speed essentially the same precise placement of the article will occur.
GRIPPER ARM JAW CLOSING OPERATION
It ha been described above how the second jaw member 26 opens with respect Jo jaw member 24 after the jaw3 24,26 had previously been in contacting relation. The preced$ng di~cu~sion provides the man kited in the art with ample understanding of how, once the jaw ~6 has been opened relative to the jaw 24, the jaw 26 again closes to engage whatever article may `--33~L3 ~37-be between the jaws 24 and 260 Hence9 the ollowing d~scuRsion of the closing of jaw 26 doe not lnclude features analogous to those already described, but rather the relationship of solenoid force requirements and spring force requirement involved in the closing of jaw 26.
When the actuator timing diva it again in a position Jo permit l~ght.to pa3s from l,ED 308 to receiver 310, the input Jo the solenoid 28 goes true to activate the solenoid 2S. The act1vation of solenoid 28 creates a force on cable 206 Jo move cable 206 in an upwards direction. The amount of force created by the solenoid depend upon such factors as the force curve for the particular solenoid used and lts duty cycle The force curve for the pull-type solenoid described herein is shown by line 500 in Fig. 15 for a solenoid operating for a duty cycle f=l/4 (f - non" time divided by the sum of Non" and "off' time. For the solenoid shown, a voltage of 54 volt DC it applied upon activatlon or lO0 milliseconds. When the ~ol~noid is seated the voltage it reduced to 27 volt DC with a r@sultant holding force of 9 pounds .
The graph of jig. 15 shows solenoid force and spring force plotted as functions of both the solenoid 25 position (upper X axis) and the position of the upper jaw (lower X ' axis) . The X axis oP Fig . 15 refers to the extension of the plunger 92 of the olenoid 28, the Nero posi~cion of the X axis being the seated position of plunger 92, the X' axis oE Fig. 15 reers to the distance 3epara~ing the lower jaw member 24 and the upper jaw member 26. The zero of axis X' is offset by about û.05 inch with respect to the zero of axis X,.
this offset occurs because after the upper jaw 2~
contacts the lower jaw 24 the solenoid plunger 92 35 . travels another 0.50 inch before seatlng. Though J
~233~3 off~e~, the acales for the axe3 X and X' are the same wince the distance rom pivot point 222 to the polnt where cable 206 attached to pin 205 ~g substantially Q~ual to the di~tanc~ from the pivot point 222 to the position of jaw 26 which selectively con~act~ jaw 24.
AGcordingly, and.in view of t:he relationship described above, for jaw 26 to contact the jaw 24 the plunger 92 must be retracted 0~125 inches. When an invert it to be engaged between jaws 24 and 26~ the plunger need be retracted 0.125 inches less the thickness of thy ~nser~. Thus, for an insert 0.005 inch thick a shown by line 502 ln the graph ox Fig.
15, the plunger 92 must be retracted 0.125 înch - 0O005 inch = 0.120 inch. Further, if it be desired that the ~ns~rt be held by a holding force of 6 pounds, for example, the plunger 92 must be retracted a further amount which will extend the expansion spring 122 sufficiently Jo that the 6pring 1~2 will cause the 1nsert to yea a 6 pound holding force A~uming, for example, that the spring 122 ha a 20 pound per inch spring rate, if the spring 122 were not preloaded the spring 122 would have to be extended 0.3 inches Jo achieve the 6 pound holding force. The distance of retraction of the plunger 92 to both move the 0.120 inch to displace jaw 26 and the 0.3 inch required to extend the spring 122 requires a total retraction of the plunger 92 on the order of 0.42 inch. Plunger retraction for such a great distance requires considerable time and result in lower solenoid forces. According Jo the prevent invention, however, the plunger 92 need not be retracted a,3 inch to extend spring 122. As described hereinbefore, housing 202 preloads the spring 122 of jigs. } 80 that the spring 122 is already extended Jo provide a ~tartins force of 5 pounds. Thus, when the solenoid is ~2~3~a~3 actuated the plunger is retracted approximately 0.120 lnch Jo thaw jaws 26 and 24 engage therebetween on invert ox ~h~cknes~ 0.005 inch, and then retracted further an additional 0.05 inch in order to extend the expansion spring 122 an amount suficient to gain an additional 1 pound holdlng force. The 0105 lnch further expansion of springs 122 (equivalent to 1 pound force) and i~3 preloaded expansion equivalent to 5 pounds force) give a total 6 pound holding for2e.
..
MISTAKE DETECTOR OPERATION
Fig. 12A show the relat$ve position of the second jaw member 26 and the tnagnetic means 420, partlcularly magnets 42~ and 424, wlth respect to the pivot point 222. As the formerly open second jaw member 26 pivoted About the pivvt point 222 to assume the position of the jaw 26' shown by phantom lines in Fig. 10, thereby closing upon the invert It the magnetic mean 420 likewise pivoted about point 222 to assume the position ox magnet holder ~26' (also shown in phantom line3). Due to the Hall Efect, aR the magnets q22 and 424 carried by holder 426 pivoted in the plane of their exposed polar faces about the pivot point 222, the flux denslty of their magnetic field as detected by the sensor 412 changed. A the sensed flux of the resultant magnetic field changed, the voltage generated by the Hall Efect tensor 400 changed proportionally. In this reyard~ it is recalled that the sensor element 412 has a constant current appl$ed ~here~o whereby the voltage generated across the electrical conductor included in the tensor element is proportlonal to the magnetic field flux in accordance with the well-known Hall Effect. The magnet 422 end 424, positionally biased by virtue of the resilient TV
~3~
bracket 430, slid acro~ the SenSQr 400 ln accordance with a ~lide-by mode. on sliding by the sensor rather than approaching the sensor in a head-orl moder a constant ~patlal relationshlp 13 maintained between the plane of the exposed magnetic poles and the plane oE
the sensor element The biasing unc~ion performed by the re~ilien~ bracket 430 provides numerous advantage.
For example, the bracket keep the magn~s 422 and 42.4 at a uniform spacing away from the sensor 412. If a uniform pacing were not mai~tainea~ the magnetlc let experienced by the sensor 412 would not be uniform.
The biasing of the bracket 430 against the magnets 422 and 424 alto help to keep out foreign particle3 such 15 as dust Moreover, the biasing overcome3 problems which might axise due to the gripplng of inert ox different dimens$onal tolerances.
A shown in Fig. 10, the pivoting of magne'c holder 426 as the second jaw member 26 clover tv engage an invert cue the imaginary line 436 to pivot to assume the position 436'. Recall that imaginary line 436 extends from the pivot po~n~ 222 to perpendicularly bisect the line 428 connecting the centers ox magnets 422 and 424. Upon a~sumin~ the pivotal po~ltion in FigO 10 as shown by the phantom lines, the point X
(the center of the magnetic field) at the intersection of lines 428' and 426' is displaced along the Y axis of Fig. lO by a distance y prom its prior position K Nat the intersection of lines 42~ and 426~ when the second jaw member was open with respect to the first jaw member The distance y i3 related to the distance x separating the firs and second jaw members by the expression 3~
\
, ,f "I , Jo !~
~41-x /AA~
_ fl _ y EBB
where A it the distance rom the pivot point 2Z2 to the center of the magnetic field (point X and where BB
l the dlstance rom the pivot point 222 to the polnt of the potential contact o the ~lrst and second jaw members. The value of the ratio x:y is thus a non-linear function of the ratio AA:~B~ For the 3peclal case lllu~trated in Fig. 10 wherein the magnet 422 and 424 are arranged immediately next to one another (i.e.
the magnet Dave edge practically touching at thy point K) the above relationship becomes essentially linear over a portlon ox it range Jo thats AA
x I _ y BB
Thus, the positioning of the magnets ~22 and 424 relative to one another it a actor in deter~4ning thy nature of thy rela~ion~hip.
In Yig. 9 the analog voltage output of thy Hall effect sensor 412 is teen a3 a function of insert thickness (i.e. the distance x separating the flrst and second jaw members at their point of potential contact). When the irst jaw member 24 and the ~e~ond jaw member 26 contact one another to the jaw is "zlosed" with no insert engaged therebetween), the analog Yolta9e output is slightly le~5 than 2 volts.
~5 When the distance x separating the jaw members 24 and 26 it about 0.1 inches, the sensor output voltage i5 in khe neighborhood of 5.5 volts. From the graph nf Fig.
9 it can be seen that a .004 inch change in insert thickne~8 result in about a 200 milivolt increa5e in tensor output. The analog voltage output o the tensor 412 it applied on lead 416 to the circuit of Fig. 8.
The analog voltage output of sensor 412 on ~%~3~:~3 lead 416 it applied to the mistake indicating cirauit 365. In thi~ regard, the voltage output on lead 416 i8 applied both to the slgnal generating mleans 367 the voltaye di~tlder network compri~lng resls~ors R16, R17,
GRIPPER ARM JAW CLOSING OPERATION
It ha been described above how the second jaw member 26 opens with respect Jo jaw member 24 after the jaw3 24,26 had previously been in contacting relation. The preced$ng di~cu~sion provides the man kited in the art with ample understanding of how, once the jaw ~6 has been opened relative to the jaw 24, the jaw 26 again closes to engage whatever article may `--33~L3 ~37-be between the jaws 24 and 260 Hence9 the ollowing d~scuRsion of the closing of jaw 26 doe not lnclude features analogous to those already described, but rather the relationship of solenoid force requirements and spring force requirement involved in the closing of jaw 26.
When the actuator timing diva it again in a position Jo permit l~ght.to pa3s from l,ED 308 to receiver 310, the input Jo the solenoid 28 goes true to activate the solenoid 2S. The act1vation of solenoid 28 creates a force on cable 206 Jo move cable 206 in an upwards direction. The amount of force created by the solenoid depend upon such factors as the force curve for the particular solenoid used and lts duty cycle The force curve for the pull-type solenoid described herein is shown by line 500 in Fig. 15 for a solenoid operating for a duty cycle f=l/4 (f - non" time divided by the sum of Non" and "off' time. For the solenoid shown, a voltage of 54 volt DC it applied upon activatlon or lO0 milliseconds. When the ~ol~noid is seated the voltage it reduced to 27 volt DC with a r@sultant holding force of 9 pounds .
The graph of jig. 15 shows solenoid force and spring force plotted as functions of both the solenoid 25 position (upper X axis) and the position of the upper jaw (lower X ' axis) . The X axis oP Fig . 15 refers to the extension of the plunger 92 of the olenoid 28, the Nero posi~cion of the X axis being the seated position of plunger 92, the X' axis oE Fig. 15 reers to the distance 3epara~ing the lower jaw member 24 and the upper jaw member 26. The zero of axis X' is offset by about û.05 inch with respect to the zero of axis X,.
this offset occurs because after the upper jaw 2~
contacts the lower jaw 24 the solenoid plunger 92 35 . travels another 0.50 inch before seatlng. Though J
~233~3 off~e~, the acales for the axe3 X and X' are the same wince the distance rom pivot point 222 to the polnt where cable 206 attached to pin 205 ~g substantially Q~ual to the di~tanc~ from the pivot point 222 to the position of jaw 26 which selectively con~act~ jaw 24.
AGcordingly, and.in view of t:he relationship described above, for jaw 26 to contact the jaw 24 the plunger 92 must be retracted 0~125 inches. When an invert it to be engaged between jaws 24 and 26~ the plunger need be retracted 0.125 inches less the thickness of thy ~nser~. Thus, for an insert 0.005 inch thick a shown by line 502 ln the graph ox Fig.
15, the plunger 92 must be retracted 0.125 înch - 0O005 inch = 0.120 inch. Further, if it be desired that the ~ns~rt be held by a holding force of 6 pounds, for example, the plunger 92 must be retracted a further amount which will extend the expansion spring 122 sufficiently Jo that the 6pring 1~2 will cause the 1nsert to yea a 6 pound holding force A~uming, for example, that the spring 122 ha a 20 pound per inch spring rate, if the spring 122 were not preloaded the spring 122 would have to be extended 0.3 inches Jo achieve the 6 pound holding force. The distance of retraction of the plunger 92 to both move the 0.120 inch to displace jaw 26 and the 0.3 inch required to extend the spring 122 requires a total retraction of the plunger 92 on the order of 0.42 inch. Plunger retraction for such a great distance requires considerable time and result in lower solenoid forces. According Jo the prevent invention, however, the plunger 92 need not be retracted a,3 inch to extend spring 122. As described hereinbefore, housing 202 preloads the spring 122 of jigs. } 80 that the spring 122 is already extended Jo provide a ~tartins force of 5 pounds. Thus, when the solenoid is ~2~3~a~3 actuated the plunger is retracted approximately 0.120 lnch Jo thaw jaws 26 and 24 engage therebetween on invert ox ~h~cknes~ 0.005 inch, and then retracted further an additional 0.05 inch in order to extend the expansion spring 122 an amount suficient to gain an additional 1 pound holdlng force. The 0105 lnch further expansion of springs 122 (equivalent to 1 pound force) and i~3 preloaded expansion equivalent to 5 pounds force) give a total 6 pound holding for2e.
..
MISTAKE DETECTOR OPERATION
Fig. 12A show the relat$ve position of the second jaw member 26 and the tnagnetic means 420, partlcularly magnets 42~ and 424, wlth respect to the pivot point 222. As the formerly open second jaw member 26 pivoted About the pivvt point 222 to assume the position of the jaw 26' shown by phantom lines in Fig. 10, thereby closing upon the invert It the magnetic mean 420 likewise pivoted about point 222 to assume the position ox magnet holder ~26' (also shown in phantom line3). Due to the Hall Efect, aR the magnets q22 and 424 carried by holder 426 pivoted in the plane of their exposed polar faces about the pivot point 222, the flux denslty of their magnetic field as detected by the sensor 412 changed. A the sensed flux of the resultant magnetic field changed, the voltage generated by the Hall Efect tensor 400 changed proportionally. In this reyard~ it is recalled that the sensor element 412 has a constant current appl$ed ~here~o whereby the voltage generated across the electrical conductor included in the tensor element is proportlonal to the magnetic field flux in accordance with the well-known Hall Effect. The magnet 422 end 424, positionally biased by virtue of the resilient TV
~3~
bracket 430, slid acro~ the SenSQr 400 ln accordance with a ~lide-by mode. on sliding by the sensor rather than approaching the sensor in a head-orl moder a constant ~patlal relationshlp 13 maintained between the plane of the exposed magnetic poles and the plane oE
the sensor element The biasing unc~ion performed by the re~ilien~ bracket 430 provides numerous advantage.
For example, the bracket keep the magn~s 422 and 42.4 at a uniform spacing away from the sensor 412. If a uniform pacing were not mai~tainea~ the magnetlc let experienced by the sensor 412 would not be uniform.
The biasing of the bracket 430 against the magnets 422 and 424 alto help to keep out foreign particle3 such 15 as dust Moreover, the biasing overcome3 problems which might axise due to the gripplng of inert ox different dimens$onal tolerances.
A shown in Fig. 10, the pivoting of magne'c holder 426 as the second jaw member 26 clover tv engage an invert cue the imaginary line 436 to pivot to assume the position 436'. Recall that imaginary line 436 extends from the pivot po~n~ 222 to perpendicularly bisect the line 428 connecting the centers ox magnets 422 and 424. Upon a~sumin~ the pivotal po~ltion in FigO 10 as shown by the phantom lines, the point X
(the center of the magnetic field) at the intersection of lines 428' and 426' is displaced along the Y axis of Fig. lO by a distance y prom its prior position K Nat the intersection of lines 42~ and 426~ when the second jaw member was open with respect to the first jaw member The distance y i3 related to the distance x separating the firs and second jaw members by the expression 3~
\
, ,f "I , Jo !~
~41-x /AA~
_ fl _ y EBB
where A it the distance rom the pivot point 2Z2 to the center of the magnetic field (point X and where BB
l the dlstance rom the pivot point 222 to the polnt of the potential contact o the ~lrst and second jaw members. The value of the ratio x:y is thus a non-linear function of the ratio AA:~B~ For the 3peclal case lllu~trated in Fig. 10 wherein the magnet 422 and 424 are arranged immediately next to one another (i.e.
the magnet Dave edge practically touching at thy point K) the above relationship becomes essentially linear over a portlon ox it range Jo thats AA
x I _ y BB
Thus, the positioning of the magnets ~22 and 424 relative to one another it a actor in deter~4ning thy nature of thy rela~ion~hip.
In Yig. 9 the analog voltage output of thy Hall effect sensor 412 is teen a3 a function of insert thickness (i.e. the distance x separating the flrst and second jaw members at their point of potential contact). When the irst jaw member 24 and the ~e~ond jaw member 26 contact one another to the jaw is "zlosed" with no insert engaged therebetween), the analog Yolta9e output is slightly le~5 than 2 volts.
~5 When the distance x separating the jaw members 24 and 26 it about 0.1 inches, the sensor output voltage i5 in khe neighborhood of 5.5 volts. From the graph nf Fig.
9 it can be seen that a .004 inch change in insert thickne~8 result in about a 200 milivolt increa5e in tensor output. The analog voltage output o the tensor 412 it applied on lead 416 to the circuit of Fig. 8.
The analog voltage output of sensor 412 on ~%~3~:~3 lead 416 it applied to the mistake indicating cirauit 365. In thi~ regard, the voltage output on lead 416 i8 applied both to the slgnal generating mleans 367 the voltaye di~tlder network compri~lng resls~ors R16, R17,
5 and R18) and to the comparing mean 368 (i.e. to the non-inverting input terminal of OP IMP 480). Signal generating means 367 generake~ a f lr~t analog voltage aignal on line 453 which l proportional Jo the analog voltage on lewd 4}69 ~lgnal generating mean 367 al~30 10 produces a ~ecorld analog voltage signal a ns:)de 450 which ~3 a f lxed percentage greater than the voltage on line 453 and a third analog voltage ~lgnal at node 452 which is a flxed percentage let Han the voltage on lone 453. As teen hereinafter, voltages at node 450 and 452 are respectively used by the OP AMP 480 [to determine lf none or too Jew articles (a "missn) are engaged by the gripper arm] and by the QP IMP 470 lto determine it zoo many articles pa "double" ) are engaged by the gril?per arm In this r~39ard, the non-lnverting 20 input terminal of OP AMP 47û receive the analog voltage slgnal from node 45~ which l a fixed percentage lest than the voltage on line 4531 and the lnverting input terminal of OP AMP 480 receive the analog voltage signal f rom node 450 (which it a f ixed percentage greater than the voltage on line 453).
The Miss OP AMP 480 compares the calibrated analog reference voltage generated by the sample and hold circuit 369 to the voltage signal at node 450 (which is a flxed percentage greater than the voltage gnat on line 453). The voltage signal at node 450 corresponds to a lower limit of acceptable jaw displaGement. If the output voltage at node 450 i6 less than the reference voltage, the output terminal ox OP AMP 480 goes true to indicate that too few inse.rts have been grabbed.
The "double" OP AMP 470 compares the calibrated analog reference voltage to the voltage signal at node ~52 which l a flxed percentage lets than the voltage signal on lLne 453). The voltage signal at node 452 corresponds to an upper limit of acceptabl.e jaw dlsplacement. If the voltag2 at node 452 exceed the reference voltage (by reason of zoo great a dls~ance ~epara~ing the gripper jaw 24 and 26), then the output terminal of OP ~M~ 470 goes trule to indicate that too many in~er~ have been grabbed.
The value of resl~ors R16 and ~17 are so choeen that the voltage at nodes 450 and 452 are at fix d percentages above and below, respectively, the voltage signal on line 453 to provide an acceptable tolcrance lS range for insert thicknesses.
At a point in the machine cycle at which the distance x separating the grlpper jaw member 24 and 26 iB to be checked (and thu6 the thlckness of the insert/in~ert~ engaged therebetween), a timing pulse lo applied on lead 486 to the ~lip=flops 472 and 482. If either flip-flop 47~ or 482 it receiving a true slgnal at its data input pin when a timing pulse it received, the Q output pln of the re~pectlve fllp-flop goes true ~0 2S to ultimately activate an appropriate LED
indicative of the detected condition If, for example, OP AMP 470 had a true output when flip-flop 472 receive a timing pulse, the Q output pin goes true so that a true signal is applied to inverting driver 474. The output oP driver 474 goes false, so that LED
476 is activated to give a visible indication that a "double" occurred. Once the mî~take indicator is observed and rectifled, the operator can reset the flip-flop by causing a reset pulse to be applied on lead 477.
~3~3 It has been mentioned earlier that the sample and hold circuit 369 generates a calibrated analog voltage signal or application to the OP AMPs 470 and 480. The calibrated reverence voltage ls generated when an operator (1) verities (during al portion of the machine cycle in which the gripper arm of the insert station is to grab an insert) thaw the gripper jaw element 24 and 26 are separated by the proper distance x (kaking into consideration the number of insert to be engaged and thy thickness of each engagëd insert (2) closes the calibration switch 467; and, ~3~ then opens the calibration wick 467. When the switch 467 ia closed the voltage signal at node 451 is applied to the non-inverting terminal of OP AMP 456. the circuit 369 hold the voltage at node 451 in binary form but provide an analog output from OP AMP 464 which it used as the calibrated analog reference voltage until the switch 467 is again closed for another calibratlon.
thus, the present invention provides a mistake detector that can be very eagily and accurately calibrated.
From the foregoing it 8 seen that the present lnventlon provides a method of easily calibrating the mLstake detectors a~ociated with eaah of the plurality of gripper arms positioned along a raceway of a multl-station insertion machine. In this respect, a lay operator who need not be a skilled technician can simply and quickly calibrate the mistake detectors for each grlpper arm. The lay operator need only approach insert statlon Sl; load the desired type 30 of insert3 into the hopper associated with insert station Sl; jog the insertion machine 10 through a portion of machine cycle during which tlme the operator can verify whether gripper arm 161 is properly engaging an appropriate number of insert Il at station Sl (meaning that gripper jaw elements 24 and 26 are 3~
.. .
separated my the proper distance during a portion of the machine cycle wherein the jaws engage the proper number of inserts), close the calibration switch 467;
end, then open the calibration 3wl~ch 467. The lay operator then move to insert station S2; loads the desired type of inserts into the hopper associated with 1nsert station S2; jogR the machine 10 through a second machine cycle to verify the engagement of grlpper arm 162 of a proper number of insert I2; closes the calibration switch associated ~herew~th; and, closes the a~ociated calibration switch. the lay operator then move Jo invert station ~3 whereat analogous lop are performed, and so on according to the number of invert stations provided with the particular machine being used.
An alternative approach for callbrating the miatake detectors a~soclated with each of the plurality o gripper arms is for the lay operator to load each insert station AL, S2, and S3 with it respective inserts. The operator then jogs the ln~ertion machine through a portion of the machine cycle durlng which time each gripper arm engages it re pectlve invert.
The operator then stops the machine and inspects Mach gripper arm to verify that a proper number o inRerts are engaged by each gripper arm. If all gripper arms are engaging the proper number of inserts, the operator then close3 a master calibration switch (~CS) which loses the calibration switch for each insert station Sl, S2, and S3. A sequence of closing and then opening the matter cali~ra~ion switch enable each sample and hold circuit to hold its calibrated analog reference voltage until another calibration operation occurs.
While the invention has been particularly shown and described with reference to the preferred ~3~3 ,. .
--46~
embodiments thereof, it will be under~t:ood by those skilled in t:he art that varlou~ al~cerations ln form and detail may ye made thereln wi~chout departing from the spirit and scope of the inventlon.
The Miss OP AMP 480 compares the calibrated analog reference voltage generated by the sample and hold circuit 369 to the voltage signal at node 450 (which is a flxed percentage greater than the voltage gnat on line 453). The voltage signal at node 450 corresponds to a lower limit of acceptable jaw displaGement. If the output voltage at node 450 i6 less than the reference voltage, the output terminal ox OP AMP 480 goes true to indicate that too few inse.rts have been grabbed.
The "double" OP AMP 470 compares the calibrated analog reference voltage to the voltage signal at node ~52 which l a flxed percentage lets than the voltage signal on lLne 453). The voltage signal at node 452 corresponds to an upper limit of acceptabl.e jaw dlsplacement. If the voltag2 at node 452 exceed the reference voltage (by reason of zoo great a dls~ance ~epara~ing the gripper jaw 24 and 26), then the output terminal of OP ~M~ 470 goes trule to indicate that too many in~er~ have been grabbed.
The value of resl~ors R16 and ~17 are so choeen that the voltage at nodes 450 and 452 are at fix d percentages above and below, respectively, the voltage signal on line 453 to provide an acceptable tolcrance lS range for insert thicknesses.
At a point in the machine cycle at which the distance x separating the grlpper jaw member 24 and 26 iB to be checked (and thu6 the thlckness of the insert/in~ert~ engaged therebetween), a timing pulse lo applied on lead 486 to the ~lip=flops 472 and 482. If either flip-flop 47~ or 482 it receiving a true slgnal at its data input pin when a timing pulse it received, the Q output pln of the re~pectlve fllp-flop goes true ~0 2S to ultimately activate an appropriate LED
indicative of the detected condition If, for example, OP AMP 470 had a true output when flip-flop 472 receive a timing pulse, the Q output pin goes true so that a true signal is applied to inverting driver 474. The output oP driver 474 goes false, so that LED
476 is activated to give a visible indication that a "double" occurred. Once the mî~take indicator is observed and rectifled, the operator can reset the flip-flop by causing a reset pulse to be applied on lead 477.
~3~3 It has been mentioned earlier that the sample and hold circuit 369 generates a calibrated analog voltage signal or application to the OP AMPs 470 and 480. The calibrated reverence voltage ls generated when an operator (1) verities (during al portion of the machine cycle in which the gripper arm of the insert station is to grab an insert) thaw the gripper jaw element 24 and 26 are separated by the proper distance x (kaking into consideration the number of insert to be engaged and thy thickness of each engagëd insert (2) closes the calibration switch 467; and, ~3~ then opens the calibration wick 467. When the switch 467 ia closed the voltage signal at node 451 is applied to the non-inverting terminal of OP AMP 456. the circuit 369 hold the voltage at node 451 in binary form but provide an analog output from OP AMP 464 which it used as the calibrated analog reference voltage until the switch 467 is again closed for another calibratlon.
thus, the present invention provides a mistake detector that can be very eagily and accurately calibrated.
From the foregoing it 8 seen that the present lnventlon provides a method of easily calibrating the mLstake detectors a~ociated with eaah of the plurality of gripper arms positioned along a raceway of a multl-station insertion machine. In this respect, a lay operator who need not be a skilled technician can simply and quickly calibrate the mistake detectors for each grlpper arm. The lay operator need only approach insert statlon Sl; load the desired type 30 of insert3 into the hopper associated with insert station Sl; jog the insertion machine 10 through a portion of machine cycle during which tlme the operator can verify whether gripper arm 161 is properly engaging an appropriate number of insert Il at station Sl (meaning that gripper jaw elements 24 and 26 are 3~
.. .
separated my the proper distance during a portion of the machine cycle wherein the jaws engage the proper number of inserts), close the calibration switch 467;
end, then open the calibration 3wl~ch 467. The lay operator then move to insert station S2; loads the desired type of inserts into the hopper associated with 1nsert station S2; jogR the machine 10 through a second machine cycle to verify the engagement of grlpper arm 162 of a proper number of insert I2; closes the calibration switch associated ~herew~th; and, closes the a~ociated calibration switch. the lay operator then move Jo invert station ~3 whereat analogous lop are performed, and so on according to the number of invert stations provided with the particular machine being used.
An alternative approach for callbrating the miatake detectors a~soclated with each of the plurality o gripper arms is for the lay operator to load each insert station AL, S2, and S3 with it respective inserts. The operator then jogs the ln~ertion machine through a portion of the machine cycle durlng which time each gripper arm engages it re pectlve invert.
The operator then stops the machine and inspects Mach gripper arm to verify that a proper number o inRerts are engaged by each gripper arm. If all gripper arms are engaging the proper number of inserts, the operator then close3 a master calibration switch (~CS) which loses the calibration switch for each insert station Sl, S2, and S3. A sequence of closing and then opening the matter cali~ra~ion switch enable each sample and hold circuit to hold its calibrated analog reference voltage until another calibration operation occurs.
While the invention has been particularly shown and described with reference to the preferred ~3~3 ,. .
--46~
embodiments thereof, it will be under~t:ood by those skilled in t:he art that varlou~ al~cerations ln form and detail may ye made thereln wi~chout departing from the spirit and scope of the inventlon.
Claims (29)
1. A gripper arm for selectively engaging and retrieving articles from a station proximate the gripper arms, said gripper arm comprising a gripper arm housing having a first end and a second end;
means at the second end of said housing for securing said gripper arm to oscillating drive means;
a first jaw member proximate said first end of said gripper arm housing;
a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member for the engagement of articles therebetween;
a solenoid mounted to said gripper arm housing, said solenoid having a plunger associated therewith, said plunger being actuatable to a first position when an electrical signal is supplied to said solenoid and to a second position in the absence of said electrical signal;
linkage means for connecting said plunger of said solenoid to said movable second jaw member whereby said movable second jaw is selectively moved toward and away from said first jaw member in response to the position of said plunger means of said solenoid;
biasing means connected intermediate said plunger of said solenoid and said second jaw member for biasing said second jaw member with respect to said first jaw member;
and, means for applying a preloading force on said biasing means.
means at the second end of said housing for securing said gripper arm to oscillating drive means;
a first jaw member proximate said first end of said gripper arm housing;
a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member for the engagement of articles therebetween;
a solenoid mounted to said gripper arm housing, said solenoid having a plunger associated therewith, said plunger being actuatable to a first position when an electrical signal is supplied to said solenoid and to a second position in the absence of said electrical signal;
linkage means for connecting said plunger of said solenoid to said movable second jaw member whereby said movable second jaw is selectively moved toward and away from said first jaw member in response to the position of said plunger means of said solenoid;
biasing means connected intermediate said plunger of said solenoid and said second jaw member for biasing said second jaw member with respect to said first jaw member;
and, means for applying a preloading force on said biasing means.
2. The gripper arm of claim 1, wherein at least one of said jaw members has a recess formed on a surface thereof oriented to contact an article to be engaged by said gripper arm, and wherein said recess has a high friction coefficient member accommodated therein.
3. The gripper arm of claim 2, wherein said high friction coefficient member is comprised of urethane.
4. The gripper arm of claim 1, wherein said means for applying a preloading force to said biasing means serves to facilitate the application of a predetermined force upon an article engaged between said first and second jaw members.
5. The gripper arm of claim 4, wherein said biasing means comprises a first spring connected intermediate said plunger of said solenoid and said second jaw member, and wherein said means for applying a preloading force serves to extend said first spring a desired distance whereby said spring causes said second jaw member to exert a predetermined force on articles engaged between said first and second jaw members.
6. The gripper arm of claim 5, wherein said means for applying a preloading force comprises a second spring concentrically mounted with respect to said first spring.
7. A gripper arm in combination with an insertion machine, said gripper arm being adapted for selective engagement and retrieval of articles from a station proximate the gripper arm in timed relationship with a machine cycle according to which said insertion machine operates, said machine being operable at a plurality of machine cycle rates and operable at any given time at a current machine cycle rate, said gripper arm combination comprising:
a gripper arm housing having a first end and a second end;
means at the second end of said housing for securing said gripper arm to oscillating drive means;
a first jaw member proximate said first end of said gripper arm housing;
a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member for the engagement of articles therebetween;
actuating means for selectively actuating the movement of said second jaw member with respect to said first jaw member;
control means for controlling said actuating means whereby the timing of the selective operation of said actuating means occurring during a machine cycle is dependent upon the machine cycle rate at which said machine is currently operating; and, linkage means for connecting said actuating means to said movable second jaw member whereby said movable second jaw is selectively moved with respect to said first jaw member in response to the operation of said actuating means.
a gripper arm housing having a first end and a second end;
means at the second end of said housing for securing said gripper arm to oscillating drive means;
a first jaw member proximate said first end of said gripper arm housing;
a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member for the engagement of articles therebetween;
actuating means for selectively actuating the movement of said second jaw member with respect to said first jaw member;
control means for controlling said actuating means whereby the timing of the selective operation of said actuating means occurring during a machine cycle is dependent upon the machine cycle rate at which said machine is currently operating; and, linkage means for connecting said actuating means to said movable second jaw member whereby said movable second jaw is selectively moved with respect to said first jaw member in response to the operation of said actuating means.
8. The gripper arm combination of claim 7, wherein said control means comprises:
first sensor means for determining said machine cycle rate;
second sensor means for determining when during each machine cycle said actuating means should be selectively operated; and, means for determining a suitable delay interval between said determination made by said second sensor means and the actual selective operation of said actuating means.
first sensor means for determining said machine cycle rate;
second sensor means for determining when during each machine cycle said actuating means should be selectively operated; and, means for determining a suitable delay interval between said determination made by said second sensor means and the actual selective operation of said actuating means.
9. The gripper arm combination of claim 8, wherein said first sensor means comprises means for generating pulses related to said machine cycle rate.
10. The gripper arm combination of claim 9, wherein said means for determining a suitable delay interval comprises:
up-down counter means, said up/down counter means being adapted to (1) count up pulses from a clocking means when enabled to count in and up direction and (2) to count down pulses from said means for generating pulses related to said machine cycle rate when enabled to count in a down direction; and, multivibrator means triggerable when said up/down counter has counted down a number of pulses equal to the number of pulses counted up, whereby when triggered said multivibrator means selectively operates said actuating means.
up-down counter means, said up/down counter means being adapted to (1) count up pulses from a clocking means when enabled to count in and up direction and (2) to count down pulses from said means for generating pulses related to said machine cycle rate when enabled to count in a down direction; and, multivibrator means triggerable when said up/down counter has counted down a number of pulses equal to the number of pulses counted up, whereby when triggered said multivibrator means selectively operates said actuating means.
11. The gripper arm combination of clam 10, wherein said multivibrator means when triggered changes the directions of counting by said counter.
12. The gripper arm combination of claim 7, whereby said actuating means comprises a solenoid, said solenoid having a plunger associated therewith, said plunger being actuable to a first position when a signal is applied to said solenoid and to a second position in the absence of said signal.
13. The gripper arm combination of claim 7, wherein the selective operation of said actuating means includes the selective enablement of said actuating means.
14. The gripper arm combination of claim 7, wherein the selective operation of said actuating means includes the selective disablement of said actuating means.
15. A method of operating a gripper arm in combination with an insertion machine, said gripper arm being adapted for selective engagement and retrieval of articles from a station proximate the gripper arm in timed relationship with a machine cycle according to which said insertion machine operates, said machine being operable at a plurality of machine cycle rates and operable at any given time at a current machine cycle rate, said gripper arm combination including a gripper arm housing having a first end and a second end with means at the second end of said housing for securing said gripper arm to oscillating drive means, said gripper arm also including a first jaw member proximate said first end of said gripper arm housing and a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member in response to the operation of actuating means for the engagement of articles between said first and second jaw members, said second jaw member being connected to said actuating means by linkage means; said method comprising the steps of:
controlling said actuating means so that said actuating means is selectively operated during a machine cycle after a time delay, the magnitude of said time delay being dependent upon the machine cycle rate at which said machine is currently operating;
selectively operating said actuation means; and, moving said second jaw member selectively with respect to said first jaw member.
controlling said actuating means so that said actuating means is selectively operated during a machine cycle after a time delay, the magnitude of said time delay being dependent upon the machine cycle rate at which said machine is currently operating;
selectively operating said actuation means; and, moving said second jaw member selectively with respect to said first jaw member.
16. The method of claim 15, wherein said step of controlling said actuation means comprises the steps of:
using first sensor means for determining said machine cycle rate;
using second sensor means for determining when during each machine cycle said actuating means should be operated;
and, determining a suitable delay interval between said determination made by said second sensor means and the actual selective operation of said actuating means.
using first sensor means for determining said machine cycle rate;
using second sensor means for determining when during each machine cycle said actuating means should be operated;
and, determining a suitable delay interval between said determination made by said second sensor means and the actual selective operation of said actuating means.
17. The method of claim 16, wherein said step of using first sensor means comprises generating pulses related to said machine cycle rate.
18. The method of claim 17, wherein the step of determining a suitable delay interval comprises:
using up/down counter means, said up/down counter means being adapted to (1) count up pulses from a clocking means when enabled to count in and up direction and (2) to count down pulses from said means for generating pulses related to said machine cycle rate when enabled to count in a down direction; and, using multivibrator means triggerable when said up/down counter has counted down a number of pulses equal to the number of pulses counted up, whereby when triggered said multivibrator means selectively operates said actuating means.
using up/down counter means, said up/down counter means being adapted to (1) count up pulses from a clocking means when enabled to count in and up direction and (2) to count down pulses from said means for generating pulses related to said machine cycle rate when enabled to count in a down direction; and, using multivibrator means triggerable when said up/down counter has counted down a number of pulses equal to the number of pulses counted up, whereby when triggered said multivibrator means selectively operates said actuating means.
19. The method of claim 18, wherein said step of using multivibrator means further comprises the step of changing the direction of counting by said counter when said multivibrator means is triggered.
20. The method of claim 15, wherein said step of selectively operating said actuation means includes the step of selectively enabling said actuation means.
21. The method of claim 15, wherein said step of selectively operating said actuation means includes the step of selectively disabling said actuation means.
22. A gripper arm in combination with an insertion machine, said gripper arm being adapted for engagement and retrieval of articles from a station proximate the gripper arm and for disengagement and deposition of said articles on a track proximate said station, said gripper arm being operable in timed relationship with a machine cycle according to which said insertion machine operates, said machine being operable at any given time at one of a plurality of machine cycle rates, said gripper arm combination comprising:
a gripper arm housing having a first end and a second end;
means for securing said gripper arm housing to oscillating drive means;
a first jaw member proximate said first end of said gripper arm housing;
a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member for the engagement of articles therebetween;
actuating means for selectively actuating the movement of said second jaw member with respect to said first jaw member;
linkage means for connecting said actuating means to said movable second jaw member whereby said movable second jaw is selectively movable toward and away from said first jaw member in response to the operation of said actuating means;
means for determining a reference point in a machine cycle at which said actuating means can be operable; and, means for determining a time interval between said reference point and a point in said machine cycle at which said actuating means is to be actually operated, the magnitude of said time interval between said referenced point and said actual operation point in a given machine cycle being related to the number of machine cycles currently being executed by said insertion machine per unit time, whereupon said actuating means is actually operated in a manner whereby articles disengaged from between said jaw means are deposited at essentially the same location on said track regardless of the number of machine cycles being executed per unit time.
a gripper arm housing having a first end and a second end;
means for securing said gripper arm housing to oscillating drive means;
a first jaw member proximate said first end of said gripper arm housing;
a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member for the engagement of articles therebetween;
actuating means for selectively actuating the movement of said second jaw member with respect to said first jaw member;
linkage means for connecting said actuating means to said movable second jaw member whereby said movable second jaw is selectively movable toward and away from said first jaw member in response to the operation of said actuating means;
means for determining a reference point in a machine cycle at which said actuating means can be operable; and, means for determining a time interval between said reference point and a point in said machine cycle at which said actuating means is to be actually operated, the magnitude of said time interval between said referenced point and said actual operation point in a given machine cycle being related to the number of machine cycles currently being executed by said insertion machine per unit time, whereupon said actuating means is actually operated in a manner whereby articles disengaged from between said jaw means are deposited at essentially the same location on said track regardless of the number of machine cycles being executed per unit time.
23. The gripper arm combination of claim 22, wherein said time interval occurs between said reference point and a point in said machine cycle whereat said actuating means is actually operated to move said second jaw member toward said first jaw member.
24. The gripper arm combination of claim 22, wherein said time interval occurs between said reference point and a point in said machine cycle whereat said actuating means is actually operated to move said second jaw member away from said first jaw member.
25. The gripper arm combination of claim 22, wherein said means for determining a reference point determines both a first reference point at which said actuating means can be operable to move said second jaw member toward said first jaw member and a second reference point at which said actuating means can be operable to move said second jaw member away from said first jaw member, and wherein said time interval occurs both between said first reference point and a point in said machine cycle at which said actuating means is actually operated to move said second jaw member toward said first jaw member and between said second reference point and a point in said machine cycle at which said actuating means is actually operated to move said second jaw member away from said first jaw member.
26. A method of operating a gripper arm in combination with an insertion machine, said gripper arm being adapted for engagement and retrieval of articles from a station proximate the gripper arm and for disengagement and deposition of said articles on a track proximate said station, said gripper arm being operable in timed relation-ship with a machine cycle according to which said insertion machine operates, said machine being operable at any given time at one of a plurality of machine cycle rates, said gripper arm combination including a gripper arm housing having a first end and a second end with means for securing said gripper arm housing to oscillating drive means, said gripper arm also including a first jaw member proximate said first end of said gripper arm housing and a second jaw member proximate said first end of said gripper arm housing, said second jaw member being selectively movable with respect to said first jaw member in response to the operation of actuating means for the engagement of articles between said first and second jaw members; said method comprising the steps of:
determining a reference point in a machine cycle at which said actuating means can be operable;
determining a time interval between said reference point and a point in said machine cycle at which said actuating means is to be actually operated, the magnitude of said time interval between said reference point and said actual operation point in a given machine cycle being related to the number of machine cycles being executed by said insertion machine per unit time; and, operating said actuating means whereby articles disengaged from between said jaw means are deposited at essentially the same location on said track regardless of the number of machine cycles being executed per unit time.
determining a reference point in a machine cycle at which said actuating means can be operable;
determining a time interval between said reference point and a point in said machine cycle at which said actuating means is to be actually operated, the magnitude of said time interval between said reference point and said actual operation point in a given machine cycle being related to the number of machine cycles being executed by said insertion machine per unit time; and, operating said actuating means whereby articles disengaged from between said jaw means are deposited at essentially the same location on said track regardless of the number of machine cycles being executed per unit time.
27. The method of claim 26, wherein said time interval occurs between said reference point and a point in said machine cycle whereat said actuating means is actually operated to move said second jaw member toward said first jaw member.
28. The method of claim 26, wherein said time interval occurs between said reference point and a point in said machine cycle whereat said actuating means is actually operated to move said second jaw member away from said first jaw member.
29. The method of claim 26, wherein said step of determining a reference point comprises the step of determining both a first reference point at which said actuating means can be operable to move said second jaw member toward said first jaw member and a second reference point at which said actuating means can be operable to move said second jaw member away from said first jaw member, and wherein said time interval occurs both between said first reference point and a point in said machine cycle at which said actuating means is actually operated to move said second jaw member toward said first jaw member and between said second reference point and a point in said machine cycle at which said actuating means is actually operated to move said second jaw member away from said first jaw member.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US64839184A | 1984-09-07 | 1984-09-07 | |
US648,391 | 1984-09-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1233443A true CA1233443A (en) | 1988-03-01 |
Family
ID=24600601
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000480288A Expired CA1233443A (en) | 1984-09-07 | 1985-04-29 | Gripper arm and method of operation |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPS6169642A (en) |
CA (1) | CA1233443A (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01174372U (en) * | 1988-05-30 | 1989-12-12 | ||
JPH02261768A (en) * | 1989-03-31 | 1990-10-24 | Hiroshi Kobayashi | Gathering hold detector in collator |
JPH03104834U (en) * | 1990-02-09 | 1991-10-30 | ||
US7748517B2 (en) * | 2004-02-04 | 2010-07-06 | Goss International Americas, Inc. | Signature transport device |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4936304A (en) * | 1972-08-05 | 1974-04-04 | ||
US3967358A (en) * | 1975-08-11 | 1976-07-06 | Globe-Union Inc. | Control system for battery plate stacking apparatus |
JPS5853746B2 (en) * | 1975-10-03 | 1983-12-01 | 松下電器産業株式会社 | Ion activity measurement electrode |
JPS591661A (en) * | 1982-06-25 | 1984-01-07 | Sumitomo Metal Ind Ltd | Manufacture of pure titanium plate with little anisotropy in yield strength |
-
1985
- 1985-04-29 CA CA000480288A patent/CA1233443A/en not_active Expired
- 1985-07-30 JP JP16964785A patent/JPS6169642A/en active Pending
Also Published As
Publication number | Publication date |
---|---|
JPS6169642A (en) | 1986-04-10 |
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