US2140986A - Printing press - Google Patents

Description

Dec. 20, 19,38." f-fjpgvX-.a'cil. ""zyfl'aae PRINTING PRESS V AFiled Aug. 1e, 19u38r 6 sheets-sheet 1j llllllllllf ulhrJHHlhHnu.

ndemlor B, Les l Kegrl) Dec- 20, 1938-4 Y L'. v. BEARING 2,140,986

` y PRINTING PRESS Filed Aug. 16, 1938 6 SheetsSheet 2 gorie? .5.

L. V. DEARING -PRINTING PRESS Dec. 20, 1938.

Filed Aug. 16, 1938 6 Sheets-Sheet 3 Dec. 20, 1938.y A 1 v. BEARING 2,140,986

PRINTING PRESS Filed Aug. 16, 1938 6 Sheets-Sheet 4 Dec. 20, 1938. L. v. BEARING 2,140,986

PRINTING PRESS Filed Aug. 16, 1938 6 Sheets-Sheet 5 Dec. 20, 1938.

1 v. BEARING PRINTING PRESS Filed Aug. 16, 1938 6 Sheets-Sheet 6 lzzle/zL/Or' Les fer Vearzllgg 'BVM W c Patented Dec. 20, 1938 PATENT oFF-ics PRINTING PRESS e Lester V. Dearing, Milwaukee,v Wis., assigner to Automatic Unit Corporation, Milwaukee, Wis., a corporation of Wisconsin 1 a f application anni 1s, 193s, sex-lain. 225,129

14 Claims.

.This'invention relates to printing presses and more` particularly tocylinder presses having a rotating impression cylinder `for carrying the paper and areciprocating bed or platen which carries type matter or plates under the cylinder for printing on'the 9949er;4

'I'he present` invention isparticularly adapted for use with any type of. reciprocating bed press. However, it is especially adaptable in connection "with so-oalied 'two-revolution cylinder presses which are often usedfor multi-color printing and in which'the registration in ysuccessive.'printing operations must bevery accurate. Furthermore, it is desirable tooperate these presses at very high speed for` quantity production 'and vstill maintainthe necessary accuracy vin registration, particularly for multiple printing operations.. In presses of this type itis,4 of course,.necessary to provide a comparatively heavy, rigid bedwhich must bereciprocated over a .comparatively long cycle of movement, and it is desirable to maintain a constanthigh speed over that portion of theA cycle during whichthe printing operation takes place and during the return o! the table after the printing stroke. 'I'he bed is heavy in order to pro-vide the necessary rigidity and maintain the required printing contactl and therefore thereversal of bed'motion at each` end ofthe stroke presents a serious problem, as lit is desir- 30 able to accomplish the reversal as smoothly and quietly as possible and with a minimum amount of lostmotion in the transmission at the revers- `ing ends of the stroke;

The tracks and guides for the bed must necessarily be very accurate in order to-prevent any lateralmotionandto maintain. accurate registration and vuniform pressure in printing, and any excessive jar or blow or lost` motion in controlling the table at the reversing ends of the cycle tends to reduce the eiliciency o( the press and cause wear and inaccuracy and.` shorten the effective life of the machine as a whole.

It has been common practice lin the past to 45 `provide dashpots at each end'of vthe tablewith co-operating pistons on the bed, whereby to absorb the shock ofr stopping 4the bed atthe end of the stroke as the drive gears are released and other gears are then engaged to perform the reverse stroke of the cycle. Also, certain gearing devices have been used, lsuch as the so`called Napier bed motion, in which a rack'is 'provided onnthe bed and `a. drive gear rotating constantly in one direction operates first on one side of the rack and then on the other, the gear being moved (ci. lol-282) i around the endsy of the rack by means of al cam cri-operating with a roller on the gear.

. Certain` other devices have been' used in' which `two or more 'racks have been provided and the drivegear operates on ilrst one and then another rack in order to provide a reverse drive.' Also, a. drive gear is sometimes shifted laterally to engage. ilrst one rack` and then another. All of these mechanisms have certain objections in that more or less' lost motion is always present in the iiexiblefconnections and other parts Lof the transmission, and particuiarlyin 'the bodily movable gears, and it has been impossible torreverse the. bed motion without considerable shock and jar, with consequent wear on the gears, tracks, `and, rollers, and other parts of the mechanisml. The present invention provides a "continuous power` drive throughout the entire cycle, including the reversingv portions thereof and` with `iixed gears so arranged that s. positive drifveis main- "tained, at all `times. and an advantageous ,har-

monic movement is obtained during deceleration and acceleration when reversing from` themaximumconstant speed in one direction to the maximum constant speed inthe opposite directionf;

, It is an important object ofithe present invention to provide a simplified construction in which the rack on the bed is in constant mesh .with the `driving gear and is at all timespositively driven iromthepowershaft.` p l.

A further object is theprovision of l.a press vof the class described in which the operating parts will cause no suddenlshocksor jarsorfclashing `of gears and vall operating parts `will maintain their accuracy over long-periods of user.

Y Another yobject is the provision ota'reclpro-"U rthe air resistance may automatically beadjusted` 40 relative to the speed of the" press and .in which the airresistance' may be relative to the decelera tion curve of the reversing transmission to lthereby assist in preventing back'lashin the trans`y mission gears." f Itis a further object toprovide-a positively driven constant speed movement of; the bed. throughfintermediate portions ofthe cycle and a positively driven harmonic movement-through `the reversing portions. Also theA invention vcon-l templates the use of momentum resisting; energy storing means whichv mayautomatica'lly be controlled relative to the speed oi' the press and will operate during the reversing portionsv of the cycle to equalize the positive driving force over the reversing portion of the cycle.

It is also an object to provide a bed mounting which will provide a freedom of movement which is particularly adaptable for use in connection with the positive drive transmission and which will maintain accurate longitudinal alignment and registration throughout the cyjcle.

Further objects will be apparent from the speciiication and the appended claims.

In the drawings:

Fig. 1 isa top plan view of a cylinder press and illustrates one embodiment of the invention.

Fig. 2 is a front end elevation oi.' the embodiment illustrated in Fig. 1. t

Fig. 3 is a fragmentary side view of the embodiment illustrated in Figs.,1 and 2 andtillustrates that portion of the driving mechanism on the left-hand side of the machine as shown in Fig. 2.

Fig. 4 is a. side elevation of the opposite side of the vpress from thatshown in Fig. 3. Y f

Fig. 5 is 1a Afragmentary sectional view through l the b ed and` supporting frame andtaken on a line sub'stazitially` corresponding to line 5-5 of Fig. 2. v Y

`Fig. 6 is aperspective view of a portion of the A, driving and reversing transmission and illustrates the' position of the 'gears and associated parts when the bed is at the end of its constant speed stroke in one direction and at bthe beginning of its decelerating movement toward the pointof reversal. I A' Y Q Fig. rI is a perspective viewsirnilar to Fig-6, but illustrates the position of the gears and associated partsjwhen the bed is at the point of re.- VerSal'and at the start of the accelerating movement inthe reverse direction. Fig. 8 is a perspective view similar to Figs. 6 and '1, but illustrates the elements after reversal and acceleration and at the point of starting the constant speed stroke inthe opposite direction from that shown in Fig. '6.

Fig. V9 is a similar perspective view, but illustrates the position of the elements at the start of the decelerating portion of the cycle at the op-l posite end of the stroke fromthat shown in Figs. 6, '1, and 8. i

Fig..10 is a fragmentary perspective View and illustrates the position ofthe rack and segment transmission at the reversing point of the movement illustrated in Fig. 9. 1

Fig.` 11 is an enlarged side elevation of the cylinder controlling mechanism. y

Fig. 12 is a top view of a portion of the cylinder controlling mechanism with the eccentric conv nectingrod shown in section ona line substantially corresponding to line |2-I2 of Figpll.

Fig. 13 isa longitudinal sectional view through one of the dash-pots or so-called air springs.

Fig. 14 is a transverse sectional view through the air cylinder shown in Fig. 13'and is taken on a line substantially corresponding to line il-H thereof. l

Fig. 15 is a diagrammatic View f the variable drive mechanism and automatic control for simultaneously controlling the speed of the bed and varying thecharacteristics of the air springs.

Fig. 16 is a fragmentary side elevation of the bed guide rollers and associated track. y

Fig. 17 is a transverse section through the guide rollers and taken on a line substantially conformv ing to line IIS-I6 of Fig. 16.

Referringto the drawings in detail. the embodiment illustrated comprises a heavy rectangular frame 2l which is preferably formed of heavy which a bed orplaten- 26 is mounted for reciprocation. Suitable so-called sliders 21 are provided between the bed and the tracks, and these sliders n comprise a plurality of spaced rollers 28 which are secured together and held in spaced relation by means ofside bars 29 (Fig. 1). The rollers rest upon the tracks on the frame, and the bed 26 is providedv with co-operating tracks 30 which restupon the rollers 2B. The slider members may be of theusual construction and provide the. equivalent of a roller bearing for free longitudinal movement of the bed 26.

Each of the sliders 21 is provided with an idler pinion 3| mounted on one of the side bars (Figs. 2 and 5). Each pinion meshes with a fixed rack 32 mounted on the associated track member. Each pinion also meshesv with a rack 33 on the table 2E. The rack and pinion arrangement between the'frame and bed maintains the slidersin proper relative position `thereto and assures a free and easy-'movement of the bed during its reciprocating cycle. The rollers and tracks are,

of course,l hardened to prevent Wear and provide the required accurate alignment.

The inner tracks 25 rare provided with opposed inwardly extending and angularly disposed track -are used on vthe bed and each bracket preferably supports two of the rollers 35, as illustrated particularly in Figs. 16 and 1'7. This construction is particularly desirable in that it eliminates the usual lateral guide-ways for the `bed 26 `and not only prevents lateral misalignment of the bed but-also retains it snugly on the rollers 28 on the sliders.' vIt has Abeen found that this construction enables veryhigh speed operation of the press while at the same time maintaining accurate registration of the printing surface and the cylinder.

Heretofore lateral and horizontal guideways have been provided between the bed and frame and, as a running clearance has been necessary in these guides, as well as constant lubrication,

f the reciprocating bed whereby a positive driving K connection is maintained throughout the entire cycle, includingY reversal, and without lateral shifting 4or other bodily movement ofthe gears. This transmission comprises a transverse drive shaft 31 mounted in suitable fixed bearings in the' frame'and having a iiy-Wheel 38 secured thereto. A transverse shaft 39 is also mounted in suitable iixed bearings and may be parallel with the shaft lnately driven in opposite `segment gears 43 and. 44l respectively. "These segment gears 437 and to gears 45 and 46,{ which latter are mounted for n 9,140,986 `31,and isprovided, preferably at `the median line of the bed, lwith a gear 40iln constant' mesh with 'arack'4i secured to the'bottom of the bed 26, as shown particularly inFlg.-2. f

Y A Icomparatively wide-faced gear 42 is secured to theend'ofthe' shaft 39 and4 this gear is alterdirections by means of 4`4` aresecured. respectively,

rotation in opposite directions on a stub shaft 41.

` The gears145 and 46 and the segments 4,3 and 44 are'constantly driven inopposite directions by the; main driveshaft 31,-the gear 45 being constantly driven in one direction bymeans of a pinion 48 on the main drive shaft meshing directly Y therewith, and the gear 45 being constantly driven in' the opposite direction a'tthe' same speedy by means of a pinion 49` on the drives'haft and operating through an idler pinion 50 in mesh with the gear 46; By thismeans; the gears the same speed and `the segments alternately, mesh `with the wide-faced gear 42 for driving the bed throughout the intermediate constant spee'd portion-of the'cycle in each direction. The segments and244 are less than 180 degree segments and are so positioned that they are` substantially oppositely disposed at each end of the bed stroke. Therefore, during the reversing' portion offthe` cycle at each end of the stroke these segments 'are out of kmesh with the wide-faced gear 42and'the out-of-mesh l"period is utilized for the bed-reversing operation.

VInl order to maintain a positive drive throughout,` the entire cycle, including reverse, a decelerating and accelerating mechanism is `pro vided for reversing the table while constantlyy maintaining a positive" drive transmission from the main drive shaft 31 to the `bed 26. This mechanism provides a harmonic motion and comframe or yoke Astroke of the bed in the prisesv a' gear 5I (Figs. 4 Vand"6) secured to the opposite end of the main drive shaft 31 and in mesh with a gear 52 mounted Yon a stub shaft 5?y extending from the frame I. "The gear 52 is provided with a crank pin .54 having a suitable bearing block 55 thereon, which block is slidably positioned in a verticalslot 56in a' slidablehrack 51, whichis, in turn, mounted on suitable tways 58. It will, therefore, `be apparent `thatgwith each revolution of the gear 52, the rack f frame51 will be reciprocated.

The frame or yoke' 51 is provided with arearwardlyextending'rack 59 arranged to mesh with a reversing segment gear A60g-,secured to the end of i `the transverse bed-driving shaft 39.' t The vtransmission gear's are of such ratio that one revolution ofthe bed-driving shaft '39 and'gear 4U thereon `may be equivalent tothe acceleration to constant speed;` the intermediate constant speed same direction and the deceleration in the same direction to the reversal point. In `other words', a complete reciprocating of the segment 60 s to slightly more than cycle of the bed requires two revolutions ofthe shaft 39 and gear '40. Thedr'iving segments 43 and 44` are each equivalent to slightly more than the exact mathematical lengthyof the constant speed stroke of the bed, whilethe meshing time with the rack 59 is "equivalent l the exact mathematical lengthof the decelerating, reversing, and accelerating movement 'of the tabler at each end of the stroke. The meshing engagement of one of the ldriving segments 43or44 'always overlaps, and is overlapped by, the meshing engagement of the vthe reversing segment is also moving in the 45 and'46. `and the segments thereon are constantly'rotated in opposite directions at *mesh with the gear position ready to' reverse.

at one end of the bed :reversing point will be reversing segment ofthe intermediate constant-speed portion vof the stroke of the bed in either direction.V `fis soon, however, as the reversing'segment B0 is operatively inmesh with the rack 5S; the constant speed drivf of mesh; in other words, 60 meshes in thev rack l59 slightly before the disengagement ofone of the ing segment moves out `main driving segments and moves out ofk mesh slightly after meshing of the other driving seg -.ment. l

i Fig. 6 illustrates the p ositiony of the gears and rack when the table `drive shaft is running ini the direction of 1 the arrow and the bed has reached the end of the constant speed portion of the stroke in one direction." `.itthis moment the crank pin 54 direction of the arrowand, due to its position at the bottom of its stroke, and dueto the ratio of gears used, the rack isl travelling in the direction of the arrow. at thelsame speed as the pitch line of the drivingjseg'ment gear 43. vIt will, therefore, .be apparent'that at thispoint of the crank-pinstroke the rack 59` and reversing segment 60 may `he in vpositive vmesh `before the driving segment 43 .is completely out of mesh with the wide-'faced gear 42. l

The overlapping engagement ofthe-gear teeth I offthe driving segments and gear and' the reverslpin, the shaft 39 will be rotating at the requiredv constant speed and the driving segment 44,will

' 42 at the intermediate constant speed rate and before the reversing'segment is out of mesh with the rack 56.

*In Fig 7 the' driving segments are completely` out of meshl and the reversing rack 59 isat the extreme end of its stroke and the bed is `in` stop In Fig. fthe bed has been reversed, the reversing rack 59 is travelling at itshighest speed, which corresponds to the constantv speed 'of the bed, and one ofthe driving segments is in rmesh for continuing the constant speedmovemen't of the bed.

`The, gear ratio for the reversing mechanism may be designed toV correspond to a predetermined ,v

length of stroke `of `the'bed'but, in any event, at'the start of the reversing portion ofthe cycle stroke.' the reversing segment 60 and rack 59 will be in the position shown in Fig. Sand at the end of thejbed stroke at the inA the `position shownfin Fig. '7, in which the segment r60 is at the exact point of reversal 'and ready to start a complete revolution in the opposite direction. f

Fig.. 8 illustrates the position ofy the vpara after.

acceleration toV maximum constant speed in the opposite direction from that shown in Fig. 6.

n In Fig.` 9 thesegment 60has made a "complete revolution fromthe position'shown in Fig; 8 and has just engaged the rack 59 for another decelerating', reversing, and accelerating movementat the' opposite end of the bed stroke.

Fig. 10 illustrates the position of the parts at i the reversing point at the saidfopposite end of "the bed stroke. It should beV noted that, at one end of the bedstroke, the segment 6D meshes with the teeth at one end of therack 59, while atthe opposite end of the bed stroke the segment meshes with the opposite end of the rack, and in both cases 'the segment starts to mesh at the center of the rack at the maximum speed and the reversal points are at opposite ends of the rack. In order to accomplish this alternate meshing vat oppositeends of the rack, the gear .52 driving the rackmay make at least one .revolution while thesegment 80 is out of mesh. The movement of the crank pin and rack may .thereby be synchronized with the movement of the bed and provide advantageous deceleration and accelera- The mechanism llust `described provides a constarrt,A positive .drive transmission between the main drive 'shaft and-the bed at all times. There is no shifting of gears and the meshing of all of the: segments takes place at the maximum pitch linespeed and maximum bed speed. Therefore, there is no clashing ofgears at any time and the table is smoothly and easily decelerated, reversed; and accelerated without shock, andwith the d'rive at all times comparable to a direct positive gear connection. s 1 .As previously stated, thebed is comparatively heavy and may be operated at high speed. lIt is, therefore, desirable to provide a novel type of compensatingdash-pots or so-called air springs comprising energy storing devices to assist in reducing the momentum of the table and to eliminategthe possibility of excessive shock andstress inthe mechanism and to equalize theA positive power application during deceleration and acceleration. InY order `.to ,accomplish this, suitable open end air cylinders El are provided at each end of the frame andeach cylinder is mounted on` a suitable bracket on the frame and arranged to receive a piston 62, which latter is mounted on a piston rod` 63 rigidly secured to the bed 26. These pistons and cylinders are so positioned that the pistons may enter the cylinders substantially at the end of each constant speed portion of a. cycle and .compress the air in the cylinders and are so proportioned that the momentum of the table is overcome sufficiently to enable positive drive deceleration and a smooth reversal and acceleration by the combined action of the air springs and thetransmission without undesirable jars or strains. l

Each cylinder 6l isl provided with a floating piston Sla` whichmaybe provided witha short piston rod `Blb and .on which is mounted a guide member Ble in the form of a perforated disc arranged to maintain the floating piston in alignment. The cylinders contain oil or other liquid, preferablyofa typenot materially affected by temperaturechanges, and each of the cylinders v1s connected to a master 011 cynnder :i4-(F1515) by means of a suitable conduit 6 5. The master cylinder is 'provided with a piston 65,' and means is provided whereby this piston may automatically be positioned relative to a corresponding bed speed. In other words, varying Vthe position of the piston 66 in the master-.cylinder I4 will position the. auxiliary piston 6l to vary the amount of fluid in the cylindersso that the characteristics of the air springs will be relative to the momentum of the bed of the press and also may be relative to the decelerating rate of the reversing transmission to prevent back. lash.

The main drive shaft 31 oi' the press may be driven from any suitable power source through a variable4 speed transmission. In the present embodiment, a variable speed Atransmission 61 (Fig. v1S driven by means of a motor 6l. and this transmission drives vthe main drive shaft 31 by means of suitable gears 69 and a driven gear 10 on the shaft 31. The variable speed transmission 61- may be of any suitable type, preferably of the type having belt-driven cones which are ,adjustable by means of a hand wheel 1I on a suitable shaft 'l2v which controls the disposition of i the cones within the variable speed mechanism. By rotation ofthe hand wheel, the cones may be adjusted to vary the speed as desired.

Al transmission is provided between the hand wheel shaft 12 andthe piston 66 of the master cylinder .64, whereby any variation of the variable speed `transmission will provide'aI relative variation of the piston 66 in the cylinder 64, whereby a predetermined amount of fluid is injected into or withdrawn from the cylinders to thereby determine the positions of the floating pistons therein. d i In the present embodiment the automatic control comprises a threaded shaft13 on the piston 66 and thisshaft is provided with a pinion 14 in mesh with a gear 15 on a shaft 16. The shaft 16 is connected to the shaft 12 of the variable speed transmission control by means of a chain 11and suitable sprockets. By this construction, whenever the variable speed transmission is adjusted by means of hand wheel 1|, the dash-pots or vairV springs will automatically be adjusted, whereby the resistance of the dash-pots is always proportional to the momentum of the printing bed.

As previously stated, the present invention is more particularly concerned with a so-called two-revolution pressthat is, wherein the cylinder 23 makes two revolutions for each cycle of lbed operation. However, it will be apparent that the cylinder may be operated in any suitable relationship which is consistent with the functioning of the reciprocating bed. Also, one or more cylinders may be used with duplicate mechanisms properlytimed to drive them and raise and lower them in proper synchronism with the movement of the bed. f

In the present embodiment, the cylinder 23 performs one revolution while the bed is moving in one direction and a second revolution while the bed is returning to its original position, in which position a paper sheet may be fed to the cylinder by any suitable feeding mechanism. As shown in Figs.v l to 5, inclusive, a vertical shaft 18 may be supported in suitable bearings adjacent the paper-feeding end of the machine, and this may provide the drive shaft for any suitable type of paper-feeding mechanism. The shaft may be driven from a horizontal shaft 18 mounted in suitable bearings on the frame of the machine and connected in driving relation to the drive shaft 18 by means of suitable spiral gears 80. The shaft 19 may be drivenfrom any suitable power source, preferably from one of the tabledriving shafts, through anyvsuitable transmission, whereby the feeding mechanism-is synchronized with the bed and cylinder movement. The particular mechanism for accomplishing Athis result is not shown, as it is well known in the art.

The paper-feeding mechanism is, of course, also synchronized with the cylinder 23, which latter is provided with a gear 8| (Fig. 4) secured to the projecting end 8,2 of the shaft on which the cylinder is mounted.' The gear 8| and cylinder secured thereto is constantly driven from the mainvdrive shaft 31 by means of the gear 5| on `thel drive shaft and an intermediate gear 33, which .,vlatter'is ln mesh with thecylindergear 0|, these gears, of course, being of a proper'ratio to producethe desired speed of the cylinder relative to .the printing'bed. As previously stated, the cylinder- 23 is raised after everyprinting stroke of vwithout further contactwiththefcylinder.. 'I'his 1 the bed, so, that the bed may complete its cycle -raising ofthe cylinder is accomplishedby means ;of -rnovable eccentric bearings which are so` arv i ranged that thetransmission gears tothel cylin- .yder are always in mesh substantially at the y-The mechanism for accomplishing this `result pitch line and in any raised or Vlowered position of the cylinder.

` y isfillustrated in detail in Figs. 1l and 12.-v The l, shaft |52` of the `cylinder lsmountedin eccentric bearings 84 which are oscillatablysupported in ,the upwardlyextending portions 22 of the frame.

2o e 'Ihese bearings Blare provided-with rearwardly qextending arms 85, -each arm being-connected is supported in suitable bearings inthe frame 2|.

.90 is moved tothe left ,from its `position shownl in Fig. 11, the eccentrics` willbe rotated to raise the cylinder 23 anda vreturnrrnovernent ofthe segment` tothe positionshown will lower the cyld kinder to its printing position. The segmentY 90 link 95, which latter is, in turn, pivoted to the isvprovided with-an outwardly extending pin or roller92which is normallyengaged by a hook or latchf93. -This rlatch is pivoted at 9lto a jwfr'aile atea. Thereforaif this latch sa is oscil- `lated, it will rotate the shaft 88 and through the aiectihgthe, pitch lineirelationship of the drive i lng gears. V

f i is provided with a roller 91 operating ina cam In order Vto 4oscillatethev 93,` the, liniel 95 slot` 98v in` agear 99.` This combined gear and" means of a transmission; comprising a pinion (Fig. 4) `on thedriveshaft 31 and the intermediate j i gears |0| and |02 rotatably mounted on astub shaft; |03. The variouszmechanisms `are so syn- Ichrenized that the cylinder-is in raised position i so when the paper is fed to the machine, and, if for any reason a sheet of paper is not `fed to the machine ate-the `propertime,` a suitable mechanism is provided so that the latchi93 willbe released -from the pin 94 and the cylinder will not be lowered, during at least one cycle ofthe printingbed. e The mechanism forreleasing the latch 93 comprises an oscillatable shaft |704 (Fig. 11i) having an` arm` |05 secured thereto and providedA with a laterally extending `pin `|06 positioned under the latch'lOS. The oscillatable shaft |04 andthe ,is `consecutively fed to the printing press in the trippingarm thereon are normally retained in the position shown in Fig. 11 as long as the paper properltimed relation. "Ihe shaft and triparm ,104. thereon .may lbe controlled from the paperfeeding `mechanism b y any suitable tripping device, not shown, the mechanism of which is well known, andit is believed unnecessary to describe it in detail. In order that the latch |03may only be raised when the lcylinder is in the raised pof sition,vfthe pin 92 on the-latchis provided with a eccentric transmission .twill raise and lower the d cylinder 23, as indicated by dotted lines in Fig. 11,

and this will be accomplishedJwithout ,materially fiat side m1 and the co-operating slot lds in the latchv |03 is of such dimension-that the llatch may only beraised and lreleased from the pin whenthe pin is in the dotted-line position Fig.

. 11)',in which position the cylinder 23 is in raised position. i ,i f f r The usual paper-feed trippingvrnechanismis so constructed that the latch |03 will remain in lowered position as longl as paper is fed consecutively in proper `timed relation to the press, and whenever paper-isnot properly fed thereto the latch.

automatically `will ,raise and will remain iny the raised position-until a sheet ofpaper isv again properly `fed to the machine.

Modifications may be made without departing from the spirit of the invention. -It sdesired, therefore, that theinvention be limitedonly by the prior art and the lscope of the appended claims.

' Having thusiiescribed this invention, what is claimed'and ldesired to be secured by Letters Patentisz-`` e v 1. In a printing press 1having,areciprocating bed with constant speed throughout an intermediate portion oftthe cycle ink each direction,

the combination with a. pair ofgearsegments positivelydriven in opposite directions and a posi itive gear connection `betweeno'ne` of lsaid segments and said bed during each intermediate movement of said bed comprising asinglerack carried by the bed and apinion constantly in mesh therewith, of ya reciprocating racl; and geardecelerating, reversing, `and accelerating movements, said` segments being'related4 toprovide alternate positive drives throughout "the,v entire cycle.

2. In a printing press havinga reciprocating bed with constant speed throughout an intermediate portion of the cycle in each'direction, a

, segment transmission to lsaid pinion fordriving saidpinion and consequentlythebed through the drive shaft,"two gear-segments positively driven inopposite directions by 'said shaft, a positive gear connection ysuccessively between said segments and said'bedduring alternate intermediate movements of said bed comprising a single racl` carried bythe bed and a pinion constantlyl in mesh Awith said rack. a rack and gear-segment transmission to said pinion' for the decelerating,

` reversing; and accelerating movements of the bed, and a positive drive transmissionv between said drive shaft and said rack, the meshing engagement of said segments beingrelated tovprovvide a positive drive from said drive shaft to the Abed throughout `the entire cycle.

3. In a printing press having a reciprocating bed, a power shaft, an oscillatable shaft, a constantly meshed rack and pinion connection between said oscillatable shaft and thebed, `a gear i secured to said oscillatable shaft.` a pair of concentric segments positively driven in opposite di- -rections from the power'shaft and arrangedto alternately mesh with said gear to positively drive the bed through a'fconstant speedintermediate portion of its cycle of motion in each direction, a

thev oscillatable shaft for positively driving the bedthrough the reversing portions of` the cycle, a reciprocating rack positively driven from the power shaft and arranged to intermittentlymesh @with said reversing gear-segment in vsuch timed relation to the operation of the oppostely turning pairrof segment-s asto positivelydrive the bed throughthe reversing portions ofthe cycle, the meshing of said reversing gear-segment and its ,65 reversing gear-segment operatively connected to.

' rack occurring betweenihe periods of meshing of the concentric segments with the gear on the oscillatable shaft and having an overlapping timed relationship with the' operation of said concentric segments so that at least one segment is always in positive mesh` to drive the bed through the entire cycle. f

4. In a printing press having a reciprocating bed, a power shaft, an oscillatable bed-driving shaft, a rack carried by the bed, a pinion xed on the oscillatable bed-driving shaft and in mesh with said rack throughout all motion of the bed and whereby all motion of the bed is`imparted thereto by the pinion on the bed-driving shaft meshing with said rack, a transmission between said power shaft and said oscillatable shaft comprising a gear secured to said oscillatable shaft,A j

a pair of concentric gear-segments arranged to alternately mesh with said oscillatable shaft gear, a constant mesh gear transmission for driving said segments in opposite directions at the same y throughout the entire reciprocating cycle of the' speed for positively driving said bed through the intermediate portion of the cycle in each direcition, a reversing gear-segment secured to said oscillatable shaft, a reciprocating rack for intermittent engagement with said reversing segment, and `a varying speed transmission from said power shaft for reciprocating said rack in timed relationship to the movement of said reversing segment whereby the meshing of said rack and segment is initiated at the highest speed of said oscillating shaft at an intermediate point on said rack when the segment is moving in either ldirection, said concentric segments and said reversing segment overlapping in driving mesh whereby at least one segment is always in driving mesn bed.

5. In a printing press having a reciprocating bed with constant speed throughout an intermediate portion of the bed motion in each direci tion, the combination of, a single rack carried by the bed, a single pinion meshing'with the rack at alltimes and throughout all portions of the bed motion, a power driven constant speed drive transmission to said pinion including a pair of oppositely turning gear-segments positively driv- Y ingly connected with said pinion throughout the intermediate portion 'of the bed motion, and a variable speed power Adriven drive transmission positively drivingly connected with said pinion during the end portions of the bed motion.

6. In a printing press having a reciprocating bed, an oscillatable shaft transverse to the linear motion of thebed, a single driving connection between said shaft and the bed operative continuously throughout the entire cycle of bed motion, a constant speed drive transmission to the oscillatable shaft for moving the bed at constant speed through the intermediate portion of its motion comprising a pair of gear-segments continuously driven in opposite directions and alternately positively acting on said oscillatable shaft at spaced intervals, a harmonic motion positive drive transmission acting on the oscillatable shaft Yduring the interim between the periods of action of said pair of gear-segments to drive the bed at the ends of its motion, and a single 'power source permanently connected with both of said drive transmissions, said drive f transmissions overlapping in their actions on the oscillatable shaft to provide an uninterrupted positive drive to said oscillatable shaft.

7. In a printing press having a reciprocating bed, an oscillatable shaft transverse to the linear motion of the bed, a single driving connection between said shaft and the bed operative continuously throughout the entire cycle of bed motion, a. constant .speed drive transmission to the oscillatable shaft .for moving the bed at constant speed through the intermediate portion of its motion comprising Aa pair of gear-segmentsV continuously driven in opposite directions and alternately positively `acting on said oscillatable shaft at spaced intervals, a reversing gear-segment fixed to the oscillatable shaft, a harmonic motion positive drive transmission acting directlyon said reversing gear segment during the interim betweenv the periods of action of said pair of gearsegmentsto drive the bed at the ends of its motion, and `a single power source permanently connected with both of said drive transmissions, said drive transmissions overlapping in their actions on the oscillatable shaft to provide anun- 'interrupted positive drive to said oscillatable shaft. i

8. In `a printing press having'a reciprocating bed with constant speed throughout an intervduring thevinterims between intervals at which said pair of gear-segments are operativato drive the bed at the ends of its motion.

9. In a printing press having a reciprocating bed, resilientmeans for resisting the momentum of said bed, and means for simultaneously varying the speed of said press and'the/ characteristics of said momentum resisting means.

l0. In a printing press having a reciprocating bed, resilientmeans forresisting the momentum of said bed, and a single manually operable means for varying the velocity of said bed and the resilience of said resisting means. i

11. In a printing press having a reciprocating bed, a variable speed mechanism for driving said press, pneumatic springs for resisting the momentum of said bed, hydraulic means for varying the pneumatic characteristics of said springs, and a single' manual `control for varying said speed mechanisml and said hydraulic means.

l2. In a printing press having a reciprocating bed and a variable speedy control mechanism, opposed air spring cylinders for opposite 'strokes of said bed, pistons controlled by said bed for co-operation with said cylinders to resist the momentum of said bed, means for varying the .f eiective air capacity of said cylindersand means for simultaneous relative adjustment of press speed and cylinder volume.

l 13. In a cylinder printing press having a reciprocating bed, a power source, a transmission from said power source to positively drive said bed through a constant speed intermediate portion of its stroke in each direction, a second 'transmission' for Vpositively driving said bed through the decelerating, reversing, and accelerating portions of its stroke whereby a' positive drive is maintained throughout the entire cycle,

a variable speed mechanism for said transmisthe extreme portions of the cycle, the positive' sions. energy storing means `effective to resist momentum to thereby assist deceleration and to assist acceleration after reversal, and means to automatically maintain the eifective characteristics of said last means relative to the driving rate of said second transmission.

14. In a printing press having a reciprocating bed. a constantspeed positive drive transmissionY for said bed .throughy intermediate portions of the stroke in each direction. a harmonic motion positive drive transmission for said bed throughout driving engagement of said transmissions overlapping at the constant speed rate to provide an uninterrupted positive drive throughout the entire cycle. and variable energy storing momentum resisting means operative during said extreme portions of the cycle andv tending to equalize the applied energy of said harmonic transmission during its positive driving engagement.

LESTER V. BEARING.

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