US3635386A

US3635386A - Strip feed mechanism

Info

Publication number: US3635386A
Application number: US5528A
Authority: US
Inventors: Karl J Kallenberg
Original assignee: ELECTRONIC SYSTEMS ENGINEERING
Current assignee: ELECTRONIC SYSTEMS ENGINEERING; ELECTRONIC SYSTEMS ENGINEERING Co
Priority date: 1970-01-26
Filing date: 1970-01-26
Publication date: 1972-01-18
Anticipated expiration: 1989-01-18

Abstract

A strip feed mechanism for precisely feeding preselected lengths of a strip material, such as a paper used in photographic printing, in response to a predetermined signal. The drive includes positive stop mechanism for precise feeding of selected lengths, and adjustable means to permit feeding different lengths as desired. The length of feed is measured precisely, and the unit includes stop means that releases to stop the feeding mechanism at an exact position. The stop signal is dependent upon the length actually fed and is not affected by inertia or time lag in the starting of drive motors.

Description

United States Patent Kallenberg [4 1 Jan. 18, 1972 [54] STRIP FEED MECHANISM 3,352,468 11/1967 Shoemaker ..226/l34 X l t l K [72] nven or Kar J allenberg, Minneapolis, Minn Primary Examiner Richard A. Schacher [73] Assignee: Electronic Systems Engineering Co., Cush- Anome -Dugger, Peterson, Johnson & Westman ing, Okla.

221 Filed: Jan. 26, 1970 [571 ABSTRACT [21] APPLNOJ 5,528 A strip feed mechanism for precisely feeding preselected lengths of a strip material, such as a paper used in photographic printing, in response to a predetermined signal. The

U-S. drive in ludes o itive stop mechanism for precise feeding of F. Id S h ..B65h 17/22 l t d l ths and adjustable means to permit feeding dif- 1 l6 0 earc ..222266/ll35t]ll362, 141, I ferent lengths as desired. The length of feed is measured 3 133 precisely, and the unit includes stop means that releases to [56] Reterences Cited stop the feeding mechanism at an exact position. The stop UNITED STATES PATENTS Stansell ..226/l35 X signal is dependent upon the length actually fed and is not affected by inertia or time lag in the starting of drive motors.

15 Claims, 8 Drawing Figures PATENTEDJANIBIQYZ 3.635386 SHEET 2 OF 4 FIG. 5

@ ll 1% all 197 INVENTOR A4421 1 xuzzvasz 4 frown/75 PATENTEUJAN IHYZ EJ635386 SHEET 3 [IF 4 STRIP FEED MECHANISM BACKGROUND OF THE INVENTION l Field of the Invention The present invention has relation to intermittent drive feed I mechanisms for feeding elongated material.

2. Prior Art In the feeding of strip material, such as used for photographic printing machines, it has been known to utilize measured feeding devices. However, these usually employ some type of a continuously running drive motor that is periodically engaged through a clutch mechanism to drive or feed rollers. In the usual case, some type of mechanism electrically disengages the clutch mechanism used when feeding is complete. This type of device is shown in U.S. Pat. No. 3,161,342, is-

sued to the present inventor. A fly back" arm is utilized in a this device. While the device works satisfactorily, it becomes somewhat complex to manufacture.

A second type of device is shown in U.S. Pat. No. 3,460,732 also issued to the present inventor. I-Iere small magnetic members are carried on a constantly rotating wheel, and means are provided for releasing the magnetic members when the paper drive is tobe initiated or is initiated at the same time the clutch mechanism to the paper drive is engaged. The magnetic members then are used for breaking the circuit to the clutch drive mechanism after they have traveled a preselected distance.

Again, the device shown in the U.S. Pat. No. 3,460,732 works satisfactorily, but in certain instances the cost of manufacture becomes quite high, the device uses a number of small parts, and also necessitates the use of an electrically actuated clutch mechanism between the drive motor and the paper or strip drive wheels.

SUMMARY OF THE INVENTION The present invention relates to a feeding mechanism which is extremely simple in operation and does not necessitate hav ing a constantly running drive motor or power means but still gives precise feeding. The present invention as shown has a drive means that is initiated in response to release of a feeding latch and which then drives the feed. When the feed means has rotated a preselected amount, the latch is dropped to stop the feed and turn off the drive motor or power means. The latch positively stops the feed at the end of each cycle and resets the mechanism for the next cycle.

A latch wheel having cogs is used and carries settable stop pins that engage a switch for breaking a circuit to stop the unit. The circuit breaking switch is on a movable arm and can be adjusted so that the amount of rotation of the latch wheel for each feeding cycle can be changed in increments, to change the length 'of material fed during each cycle.

The unit is extremely simple to manufacture, low in cost, and utilizes a minimum number of parts. Additionally, the drive means for the feed mechanism does not have to be constantly running.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary schematic side elevational view of a strip feeding device including mechanism made according to the present invention;

FIG. 2 is a fragmentary side elevational view of the exterior of the case showing the means for adjusting strip-feed length;

FIG. 3 is a fragmentary top sectional view of thestrip'feed mechanism made according to the present invention and taken as on line 3-3 in FIG. 1;

FIG. 4 is an enlarged sectional view taken as on line 4-4 in FIG. 2'

]FIG. 5 is a sectional view taken as on line 5-5 in FIG. 4;

FIG. 6 is a fragmentary sectional view taken as on line 6-6 in FIG. 2;

FIG. 7 is a fragmentary sectional view taken as on line 7--7 in FIG. 6; and

FIG. 8 is a schematic diagram of an electrical circuit used for controlling the strip feed mechanism of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A photographic printer 10, for example, of the same type that is shown in U.S. Pat. No. 3,460,732, is shown schematically for-purposes of illustration. The unit includes a housing 11 that forms a frame for the various components. The printing section or work station is in the center, for example between lines 12. A roll 13 of photographic printing paper forming a strip supply is positioned at one end of the housing, and a takeup roll 14 for photographically printed paper or strip material is positioned at the other end of the machine 10. The strip feed mechanism is illustrated generally at 15 and is positioned adjacent the takeup roll. In other words, the feed mechanism 15 is on the opposite side of the printing station 12 from the supply roll 13. The strip of paper being fed illustrated at 16, which extends across the printing station 12, remains under tension in the work station.

The supply roll 13 is mounted on a pair of idler rollers 17 and 18 which are rotatably mounted on the frame, and the strip 16 passes from this supply roll l3undemeath an inertia takeup roller 19, over a guide roller 21, through the printing station 12, and then over a guide roller 22 on the opposite side of the printing station. The paper strip 16 is pinched against the outer surface of this guide roller 22 with a pair of spaced apart resilient pinch-drive rollers 23 mounted onto a common pinch roller shaft 24. The guide roller 22 is mounted onto a shaft that extends across the frame, and is rotatably mounted thereon. The pinch roller shaft 24 is rotatably mounted onto brackets 25 that are spring loaded with springs 26 fastened to the sides of the frame as at 27. The paper strip 16 passes from between the guide and pinch rollers, and underneath a tension control roller 30. The tension control roller 30 is mounted on arms 31, that are pivoted and are spring loaded with a spring 32 to put a controlled tension on the strip of material, and to cushion the starting and stopping shocks when the paper is being fed. The paper takeup roll 14 is supported on an idler roller 33, and a takeup drive roller 34. The takeup roll is cradled on the

rollers

33 and 34, which are rotatably mounted on the frame. The roller 34 is driven with a sprocket 35 through a chain 36 from a drive sprocket 37 on a paper takeup drive motor 38. The drive to the roller 34 is energized whenever the tension in strip 16 reduces to permit the arms 31 to drop. A switch 38A having an actuator 38B is closed by an arm 31 when the feeding starts, because the roll 30 and arms 31 drop. The motor 38 then starts to run, driving the takeup roll and it will continue to run until the roll 30 is lifted clearing the finger 38B. Usually this is after the feed has stopped and the takeup roll tensions the strip 16 to cause roll 30 and arms 31 to raise. The roller 30 and the roller 19 provide some cushion so that the inertia of the supply roll 13 does not cause the strip to be torn when it is initially fed, and insures that the feeding will be v made without having the paper strip tear.

The brackets 25 for mounting the pinch rollers permit the spring 26 to pull the pinch roll shaft in direction to wedge the pinch roll against the guide roll 22, with the strip 16 between the roll surfaces. I

The strip 16 of paper or other material is fed intemiittently in response to predetermined signals. The feed drive occurs whenever a latch on the drive is released and a feed motor 40, is energized (see FIG. 3). The motor 40 has an output shaft 41 driving a sprocket 42 that in turn drives a chain 43. The chain 43 drives another sprocket that drives through a friction clutch 44 to drive a strip drive wheel 45. The clutch 44 is a friction slip clutch having two metal plates with a friction plate between. The drive plate for the slip clutch is connected to the drive sprocket and is rotatably mounted with respect to the drive wheel 45 on the shaft 46 for wheel 45. The second plate or inner plate (next to the wheel 45) is fixed or drivably attached with respect to the wheel. The wheel itself is drivably mounted on shaft 46. A spring is utilized for urging the first or outer plate of the friction clutch 44 toward the second plate so there is force on the friction disc. Shaft 46 extends across the housing and is mounted in suitable bearings on the frame. A second drive wheel 47 is also drivably mounted to the shaft 46 on the opposite end thereof from wheel 45, adjacent the other sidewall of the frame or housing 11. It should be noted that the arms 31 are mounted on this shaft 46 and thus that the roller 30 pivots about the axis of the shaft 46.

The drive or feed

wheels

45 and 47 are used to drive the pinchfeed rollers 23. As can be seen, the shaft 24 at its ends adjacent the brackets 25, carries short rollers 50. These rollers 50 are urged against the surfaces of the

feed wheels

45 and 47 under the tension from the springs 26. The brackets 25 are arranged so that the rollers 50 are jammed against the surfaces of the feed rolls 45 and 47 and at the same time these pinch rolls 23 are forced against the surface of the roll 22. Thus the shaft carrying the

rolls

23 and 50 is wedged under spring pressure against the roll 22 and

wheels

45 and 47. The spring pressure from the springs 26 insures that the pinch rolls bear against the paper strip 16 to pinch the strip against the guide roller 22 and also insures that the rolls 50 are firmly urged against the surfaces of the

wheels

45 and 47 so that a positive drive results. The outer surfaces of

wheels

45 and 47 can be of a rough surface and rolls 50 may be of high friction coefficient material.

The shaft 46 extends through a sidewall 51 of the housing 11 (see FIG. 4), and a latch ratchet wheel assembly 52 is drivably mounted onto the outer end of the shaft. The latch wheel assembly 52 actually is made up in two segments, and is used for positively controlling the amount of feed of the strip 16. A desired length of strip to be fed can be preselected. The latch wheel assembly 52 as shown, has a first cog ratchet wheel section 53 which comprises a latch section. As shown, the outer periphery of the ratchet wheel 53 has a plurality of receptacles 54 defining latch receptacles. A second portion of the wheel assembly 52 comprises a housing 55 which houses a plurality of axially extending pins 56. There is one pin 56 aligned with each of the receptacles 54. The pins 56 are detented pins. Each pin has a pair of annular recesses around its periphery. A garter spring 57 is placed in a provided groove around the periphery of the wheel and partially enters receptacles for the pins 56 so that the spring will engage one or the other of the annular recesses on each of the pins 56. The spring 57 thus will retain the pins 56 either retracted as shown at the bottom position of the wheel in FIG. 4 or in a set position as shown at the top of the wheel in FIG. 4. The pins 56 are moved from this retracted position wherein they are flush with the side surface 60 of the latch wheel, to their set position where they protrude outwardly beyond this side surface 60 each time the latch is used to stop the feeding.

The strip feed device has a latch mechanism illustrated generally at 61 adjacent the bottom of the latch wheel assembly, and operating in conjunction with the latch ratchet wheel portion of the latch wheel assembly to positively stop the feeding of the strip 16 at a preselected position. The latch mechanism includes a latch dog 62 that is mounted in a slot in a bracket 63 so that it will pivot with respect to this bracket (see FIGS. 4, 6 and 7) and also will slide in and out (in axial direction of the shaft 46) as shown in FlGS. 4 and 7 in response to movement of a rotary-type solenoid 64. The bracket 63 and solenoid 64 are mounted to a bracket 81 that is fastened to the wall 51. The solenoid 64 has a rotor 78 carrying an output pin 65 that rotates slightly about a central axis when the solenoid is energized. The solenoid is shown in energized position in FIG. 4. The dotted line position of pin 65 shows the solenoid in its relaxed position. The solenoid 64 is spring loaded to its relaxed position.

The latch dog 62 extends laterally from the solenoid through provided openings in wall 51 and has cutout portions in the center part thereof. The latch dog 62 has a slot defined therein which rides over a guide-stop bar 66 attached to the sidewall 51 of the housing,.and as shown in H6. where the latch wheel is partially broken away, the guide bar 66 has an upright end portion 67 that acts as a stop to intercept movement of the latch dog along this guide bar in direction as indicated by the arrow 71 after the latch has moved to a preselected position in this direction. The latch dog has a cutout portion 72, which has a bottom edge positioned to clear the periphery of the cogged wheel. The recess also forms a shoulder 73 aligned with the inner side surface of the cogged wheel 53, and of size so that it will slide into the receptacles 54 and will hold the latch wheel from turning because the cogs will stop against the latch dog when the dog is in its relaxed position.

In addition, the latch dog has an upright end member 74 with a bent over tab which is positioned to engage the pin 56 aligned with or corresponding to the receptacle 54 which the latch dog enters. When the latch dog 62 is moved to its at rest" or latched position, the end member 74 will push the corresponding one of .the pins 56 from its neutral position to its set position protruding outwardly beyond the surface 60. This is done at the same time that the shoulder 73 enters one of the receptacles 54 to positively stop the wheel 53 when the latch dog collides against the upright member 67 to positively stop the cogged wheel at this rotational position and thus stop the paper feed. The latch dog is also spring loaded to pivot in bracket 63 in direction opposite that from indicated by the arrow 71 through the use of an elongated pin or bolt 75 which is attached to the latch dog, and a spring 76 that in turn is attached to the bolt 75 and to a pin 77 which is fixed to a bracket 81 attached to wall 51. The spring 76 will insure that the latch dog 62 pivots so that it is back and set for stopping the latch wheel. The latch will slide in axial direction along pin 65 a short distance.

ln addition, the latch dog includes a switch actuating lug 79 extending downwardly therefrom and adapted to engage and actuate a switch 80 mounted onto bracket 81. The bracket 81 is U" shaped, as shown.

The bracket 81 has an upright wall and is used for mounting a select assembly for selecting and controlling the lengths of paper to be fed. The select assembly includes a shaft 85 rotatably mounted in the upright wall of bracket 81 and a selector wheel 86 and control knob 87 are both drivably mounted onto the shaft. The shaft 85 can be slid in axial direction as well as rotated. A hub 88 is mounted onto the sidewall of the bracket 81, and the shaft 85 is rotatably mounted therein. A control lug 91 is drivably mounted on the shaft 85 on the inner end thereof and a spring 92 is positioned over the hub 88, and between the inner surfaces of the upright wall of bracket 81 and the lug so that the knob and shaft 85 are urged in direction as indicated by the arrow 92A. The wheel 86 has a plurality of holes therein, as can perhaps best be seen in FIG. 2, and the holes are of size to fit over a small stud 93 that is fixed to the wall of bracket 81. By pulling the knob in direction opposite from arrow 92A against the action of the spring 88, the wheel 86 can be released from the stud 93 and rotated to a desired position.

At the same time, therefore, the lug 91 will be rotated. As shown, the lug 91 has an arm 94 drivably mounted thereon and the arm in turn carries a switch 95 thereon. A switch actuator wheel 96 is rotatably mounted about the axis of a pin 97 mounted on a support plate 100 which is mounted on the outer end of arm 94. The switch actuator wheel is a star shaped wheel, as perhaps can be best seen in FIG. 3, and a switch actuator finger 101 is positioned so that it will be moved by the lugs on the star wheel when the wheel rotates. In other words, when the finger is in a central position between the lugs and the star wheel, the switch will be in its open position, and when the wheel rotates the lugs move the finger to actuate the switch 95. The star wheel actually rotates an amount equal to one lug spacing each time it is actuated, so that the switch 95 will be momentarily actuated and then released again.

The plate 100 also carries a pin return guide block 106 mounted thereon. The guide block is made of material having a low coefficient of friction and has a rounded end portion that engages a set pin as the wheel turns past the plate and pushes it back to its retracted or neutral position. Thus. only one pin will be set, and it is retracted as soon as it has operated switch 95 to stop strip feed.

The strip drive unit is controlled through a holding relay. When a momentary electrical signal is given for the unit to feed, for example by depression of a pushbutton 107 momentarily, the signal energizes a holding relay 105 which "looks on" through its own contacts to power coming through switch 95, and operates the solenoid 64. The solenoid 64 goes to its by the block 106 when the wheel 52 moves past the block.

energized position (solid lines in-FlG. 4) and releases the latch shoulder 73 from the receptacle 54 of the wheel 53. The shoulder 73 is withdrawn from the receptacle 54 in which it was placed. it should be noted that the pin 56 corresponding to this receptacle 54 holding the latch dog -will have been moved to its set position when the latch dog had entered that receptacle, so that the pin 56 corresponding to that receptacle will be protruding beyond the outersurface 60 of the wheel. When the latch dog is moved to its wheel release position (the solenoid is energized), the lug 79 will move away from the switch 80, actuating the switch and then in turn causing the motor 40 to be energized. The motor 40 has a small brake 102 thereon acting against a wheel 103 that is directly connected to the shaft of the motor. The brake is solenoid operated and at the same time that the-motor 'is energized, the brake 102 will be released by withdrawing the brake shoe 104 from the wheel 103 and permitting the motor 40 to start. The motor will start, driving the chain 43 and in turn driving through the friction clutch 44 to the wheel 45, shaft 46 and wheel 47. These

wheels

45 and 47 will in turn drive against the rolls 50, driving the pinch rollers through the shaft 24 and positively feeding paper. Because the latch dog shoulder 73 has been withdrawn, feeding can occur.

The control signal is momentary, but the power to the solenoid is carried through a holding relay 105 that in turn is locked on through arm switch 95. The unit will thus continue to drive, until the wheel 53 hasrotated a sufficient amount so that the protruding pin 56 (set by the latch dog at the end of the previous cycle) will engage one of the lugs on the star control wheel 96 causing the switch control wheel to rotate about its upright axis one space, thereby opening the switch 95. Opening switch 95 breaks the holding circuit to the holding relay 105 and thus to solenoid 64. When the circuit is broken, the latch dog 62 will be pulled back into a preselected one of the receptacles 54 so that the shoulder 73 will enter a receptacle 54 on the cog wheel, and the tab or lug 79 will open switch 00, stopping motor 40 and setting the brake on the motor 40. At the same time, the pin 56 corresponding to this receptacle 54 will be pushed out into its set position. When the latch dog is released, spring 76 acts to pull the latch toward rotor 78 to take up any pivoting movement of the latch and move it in direction opposite from arrow 71 to the solid line position of FIG. 7. Then the cog wheel can coast until the latch dog comes to the stop against the upright member 67. The latch dog thus will move a short distance in direction indicated by arrow 71 after the dog has entered a receptacle54. The feed will be positively stopped when the latch dog stops against this upright member 67. A precise length of strip material thus has been fed. The feed motor 40 is deenergized. The take up motor 38 will continue to run until the tension in strip 16 lifts roller 30 and arms 31 from the switch actuator 38B thereby opening switch 38A and stopping the motor 38.

However, the coasting or inertia of the feed mechanism will continue to move the wheel 52 so that the latch dog will positively come against its stop member 67 in a precise preselected position. lf a different length of strip is to be fed, the knob and control wheel 86 are reset so that a difi'erent hole is positioned with the stud 93. This will move the entire arm 94, switch 95 and its control wheel 96 to a different angular position meaning that the control wheel assembly will have to rotate a different number of degrees beforethe set pin '56 engages the star wheel 96, opens switch 95 and breaks the cir- The term strip material" has been used, and of course, this includes sheets, rods or other elongated forms of material. Further the principles are not limited merely to rotary feeding mechanisms, but can be employed with linear feeding devices.

1 claim:

1. A mechanism for feeding preselected lengths of material comprising feed means for said material including power means and latch means, said latch means including an element movable between a normal feed-permitting and a feed posi-v tion, control means to hold said element in said feed-permitting position in response to a predetermined signal, said element including an actuator, means controlled by said actuator to energize said power means when said element moves to feed-stopping feed-permitting position, and disabling means to disable said control means when said feed means has fed a preselected amount of strip material.

2. A mechanism for feeding preselected lengths of elongated material comprising a supply of material, elongated feed means for removing said material from said supply, and drive means for said feed means, said feed means including latch means, said latch means having a latch ratchet movable with said feed means, and a latch dog, said latch dog being movable between a first normal position engaging said latch ratchet thereby preventing movement of said feed means to a second position spaced from said latch ratchet, means to urge said latch ratchet to its first position, control means activated by said latch dog in its second position to energize said drive means, means to move said latch dog to said second position and retain said latch dog in said second position in response to a predetermined signal, and disabling means to disable said means holding said latch dog in its second position after said feed means has fed a preselected amount of material thereby to deenergize said drive means.

3. The combination as specified in claim 2 wherein said drive means includes a rotary element and said latch ratchet comprises a wheel member having a plurality of receptacles therein, said latch dog entering one of said receptacles whenever said dog moves to its first position.

4. The mechanism of claim 3 wherein said disabling means comprises means positioned adjacent the path of movement of said latch ratchet, and spaced from said latch dog, a plurality of settable members carried by said latch ratchet, one corresponding to each of the holding positions of said latch dog, said settable members being movable from a retracted position to a set position, means on said latch dog to set a settable pin corresponding to the position on the latch ratchet of said latch dog when said latch dog moves to its first position, said members being positioned to actuate said disabling means when said members are in said set position and are moved past said disabling means by said latch ratchet during operation of said feed means, and means to move said pins to their neutral positions when they have passed said switch.

5. The combination as specified in claim 4 and means mounting a portion of said disabling means for movement adjacent the path of travel of said latch ratchet with respect to said latch dog, and stop means for selectively holding said portion in a desired position adjacent the path of travel of said latch ratchet.

6. The combination as specified in claim 3 wherein said latch dog moves laterally from said wheel member to be withdrawn from a receptacle as said latch dog is moved to said second position, and said latch ratchet also is moved generally in opposite direction of movement of said wheel member as said latch dog moves to said second position after said latch dog has been withdrawn from said receptacles, said disabling means releasing said latch dog from its second position and said latch dog first moving laterally to engage a receptacle in said wheel member and deenergize said power means prior to reaching said first position, and said latch dog moving with said wheel member under inertial forces to said first position after said power means has been deenergized by movement of said latch dog away from its second position, and positive stop means engaging said latch dog in position in a receptacle in said wheel to prevent movement of said wheel when said dog has reached its first position.

7. The combination as specified in claim 3 wherein said means to hold said latch dog in its second position comprises a rotary solenoid having an axis substantially normal to axis of movement of said wheel member, a pin mounted on and driven in rotational direction by said rotary solenoid and spaced from the axis of said solenoid, said latch dog being mounted for movement on said pin in direction of the axis of rotation of said'solenoid also being moved with said pin laterally to the plane of movement of said wheel when said solenoid is operated to withdraw said dog from a receptacle in said wheel when said latch dog is first moved toward said second position, and bias means to slide said latch dog on said pin in opposite direction from direction of movement of said wheel member after said latch dog has moved laterally as said latch dog moves to its second position, said latch dog first moving laterally to engagea receptacle in said wheel member and deenergizing said power means and subsequently moving along said pin under influence of said wheel member to said latch dog first position after said disabling means has operated.

8. The combination as specified in claim 2 'wherein said means for holding said latch dog in its second position comprises solenoid means operated in response to an electrical signal.

9. The combination as specified in claim 2, and means to mount said latch dog for limited movement with said latch ratchet as said latch dog moves from said second position toward said first position, said latch dog first moving to engage said latch ratchet after disabling means has been activated whereby said latch ratchet can coast with said latch dog engaged in said latch ratchet until the latch dog reaches its first position.

10. A mechanism for feeding preselected lengths of strip material comprising a supply of material in strip form, feed means for removing said strip material from said supply, and drive means for said feed means including a drive motor and a rotatable element, latch means for said rotatable element, said latch means including a latch ratchet comprising a wheel member having a plurality of receptacles defined therein and a latch dog, means to move said latch dog between a first position engaging one of the receptacles of said latch ratchet thereby preventing movement of said rotatable element to a second position spaced from said latch ratchet, means to hold said latch dog spaced from said latch ratchet in response to a predetermined signal, and disabling means to disable said means holding said latch dog spaced from said latch ratchet after said feed means has traveled a preselected amount, said disabling means comprising electrical circuit holding means switch means positioned adjacent the path of movement of said wheel for disabling said circuit holding means, a plurality of pins carried by said wheel member, one pin corresponding to each of the receptacles in said wheel member, said pins beingmovable from a retracted position to a set position, means on said latch dog to set a pin corresponding to the receptacle said latch dog enters when said latch dog moves to its first position, said pins being positioned to actuate said switch means when a pin is in said set position and a pin in set position is moved by said wheel member past said switch, and means to move each set pin to its neutral position after said set pin has moved past said switch.

11. The combination as specified in claim 10, means mounting said switch means for movement about the axis of rotation of said wheel, and stop means for selectively holding said switch means in an angular position about said axis of movement of said wheel.

12. The combination as specified in claim 10 and means including switch means actuated by movement of said latch dog to its second position to energize said motor for said feed means.

13. The combination as specified in claim 12 and friction clutch means between said motor and said drive means.

14. The combination as specified in claim 12 wherein said means for holding said latch dog in its second position comprises solenoid means operated in response to an electrical signal.

15. The combination as specified in claim 14 and spring means urging said latch dog toward its first position, said solenoid means overcoming the force of said spring means.

@2 3 UNITED STATES PATENT oEETcE CERTIFICATE 0F CORRECTWN Patent No. 3 $3 5,386 Dated January 18, 1972 Karl J. Kal'lenberg Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

"* Column 8, Line 33 (clash 13, line 1) "Claim 12 Column 8, Line 35 (Claim 14, line 1) should be--Cl-aim lO--; "Claim 12'' should be--Claim lO--.

Signed and sealed this 26th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

1. A mechanism for feeding preselected lengths of material comprising feed means for said material including power means and latch means, said latch means including an element movable between a normal feed-permitting and a feed position, control means to hold said element in said feed-permitting position in response to a predetermined signal, said element including an actuator, means controlled by said actuator to energize said power means when said element moves to feed-stopping feedpermitting position, and disabling means to disable said control means when said feed means has fed a preselected amount of strip material.

7. The combination as specified in claim 3 wherein said means to hold said latch dog in its second position comprises a rotary solenoid having an axis substantially normal to axis of movement of said wheel member, a pin mounted on and driven in rotational direction by said rotary solenoid and spaced from the axis of said solenoid, said latch dog being mounted for movement on said pin in direction of the axis of rotation of said solenoid also being moved with said pin laterally to the plane of movement of said wheel when said solenoid is operated to withdraw said dog from a receptacle in said wheel when said latch dog is first moved toward said second position, and bias means to slide said latch dog on said pin in opposite direction from direction of movement of said wheel member after said latch dog has moved laterally as said latch dog moves to its second position, said latch dog first moving laterally to engage a receptacle in said wheel member and deenergizing said power means and subsequently moving along said pin under influence of said wheel member to said latch dog first position after said disabling means has operated.

8. The combination as specified in claim 2 wherein said means for holding said latch dog in its second position comprises solenoid means operated in response to an electrical signal.

10. A mechanism for feeding preselected lengths of strip material comprising a supply of material in strip form, feed means for removing said strip material from said supply, and drive means for said feed means including a drive motor and a rotatable element, latch means for said rotatable element, said latch means including a latch ratchet comprising a wheel member having a plurality of receptacles defined therein and a latch dog, means to move said latch dog between a first position engaging one of the receptacles of said latch ratchet thereby preventing movement of said rotatable element to a second position spaced from said latch ratchet, means to hold said latch dog spaced from said latch ratchet in response to a predetermined signal, and disabling means to disable said means holding said latch dog spaced from said latch ratchet after said feed means has traveled a preselected amount, said disabling means comprising electrical circuit holding means, switch means positioned adjacent the path of movement of said wheel for disabling said circuit holding means, a plurality of pins carried by said wheel member, one pin corresponding to each of the receptacles in said wheel member, said pins being movable from a retracted position to a set position, means on said latch dog to set a pin corresponding to the receptacle said latch dog enters when said latch dog moves to its first position, said pins being positioned to actuate said switch means when a pin is in said set position and a pin in set position is moved by said wheel member past said switch, and means to move each set pin to its neutral position after said set pin has moved past said switch.