US2942878A - Sheet delivery slowdown - Google Patents

Description

June 28, 1960 v. N. YINGLING ETAL 2,942,873

SHEET DELIVERY sLowDowN 4 Sheets-Sheet 1 Filed Oct. 4. 1956 June 28, 1960 v. N. Y|NGL|NG ET AL 2,942,878

SHEET DELIVERY sLowDowN Filed oct. 4. 1956 4 sheets-sheet 2 Ulla v Y El i Q f L wxga@ @f 0%, ,wz ff j, Arran/v ya June 28, 1960 v. N. YINGLING ETAL SHEET DELIVERY SLOWDOWN A 4 Sheets-Sheet I5 Filed O01. 4, 1956 rllll J www .d 7- TOP/YEAS' June 28, 1960 v. N. YINGLING ETAL 2,942,878

SHEET DELIVERY sLownowN Filed oct. 4. 195s 4 sheets-sheet 4 56.13 mi )Q $5 MQW/@4.4M

r raaf/Sys Patented June 28,v 1960 SHEET DELIVERY SLOWD OWN Victor N. Yingling, Cleveland, and Howard J. Seel,

Chagrin Falls, Ohio, assignors to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed Oct. 4, 1956, Ser. No. 613,9l5

26 Claims. (Cl. 271--79} This invention relates to improvements in sheet delivery slowdowns, that is to say means for slowing down the rate of travel of a sheet being deposited upon a delivery pile by a delivery mechanism employed in connection with a high speed printing press. Sheets of large size moving rapidly possess considerable inertia, and reducing them to zero speed in vthe very short interval available presents a difficult problem.

One method presentlyused with considerable success on paper sheets is disclosed in Patent 2,657,052 to T. l. Elliott in which the tail end of a sheet is dragged over vacuum wheels revolving at a speed slower than sheet speed. Two difficulties have arisen in the operation of this device when used in the delivery of a rotary offset press. First, Where cardboard sheets are being handled they do not conform tothe curved sui-face of the suction wheels, and thus the suction is not as effective as upon lighter weight stock, and second, the openings in the suction wheel become clogged with offset powder and lint reducing the suction.

Another method used for assisting in the depositing of sheets onto the delivery pile is shown in Patents 2,208,978 to Harrold et al. and 2,130,841 to Eckhard. ln both of these patented devices, metal suckers are used. ln the former patent, sheets are iirst dragged across the suction mouths, vacuum is next applied to the suckers, and then the suckers travel at a decelerating speed to deposit the sheets on the pile. In the latter patent, the suckers tirst travel with the sheet while vacuum is on, they next stop abruptly and remain in stopped position Va short while, and then move vertically downward. lt cannot be determined from the patent -at what speed the suckers are traveling while both they and grippers hold a sheet but it is a fair presumption that some slippage is present between the suckers and a sheet, due either to a difference in sheet and sucker speed or to the inertia 'of the sheet when the suckers abruptly stop before they begin moving down. Due to this slippage, it has heretofore been impossible as a practical matter to use any material for the suckers other than one capable of withstanding wear, eg., metal. For this reason, the patented devices are unable to effectively slow down relatively stiff, heavy sheet material such as cardboard, since the metal suckers are unable to readily conform to the sheets to positivel;l grip them. Furthermore, the thicker the sheets, the stiffer and heavier they become. It can be seen therefore that the problem becomes more acute with an increase in the thickness of the sheet material handled.

lt is therefore an object of this invention to provide a method and mechanism for slowing down and gently depositing sheets onto a pile regardless of the thickness, stiffness, or weight of such sheets.

Another object of the invention is to provide such slowdown mechanism with rubber stickers, and to so operate such mechanism that wear of the rubber suckers is kept to a minimum.

A further object'of the invention is to provide suckers in a delivery slowdown mechanism, which suckers 'are capable of conforming to the sheet material being delivered.

Another object of the invention is to provide sheet slowdown mechanism having suckers engageable with the tails of sheets to gently deposit them onto a pile, said slowdown mechanism being operated by a rotary drive and moving said suckers in a continuous path free of any stopping period.

Still another object of the invention is to provide sheet jogging mechanism along the rear of a pile adjacent the slowdown mechanism, both said jogging and slowdown mechanisms being driven from a common rotary shft on an axis fixed relative to said mechanisms.

Another object' of the invention is the provision of suction means' for slowing down the movement of a sheet in a delivery 'which shall be maintained free of olset powder and other foreign matter.

Another object -is the provision of a sucker which travels at a speed at least as great as sheet speed when it grips the sheet o that there isA no slippage` between the sucker and shee and correspondingly little wear upon' the sucker. l

Another object 'ofthe inventionis to provide that' the slowdown mechanism move the suckers in a generally arcuate path 'meeting the sheet path, means also being provided for maintaining the sheets in their path' for proper reception 1bythe suckers.

Still anotherobje'et of the invention is to provide the combination of stationary suction means of metal or the like acting on the underside of a sheet being movedvover a pile by gripper conveyors so as tomaintain the sheet relatively taut, and movable suction meansl of rubber or the like engageable with the sheet while traveling at least as fast as sheet speed and decelerating the sheet-after release by the grippers to deposit it on the pile.

Another object is the provision of air blast means for positively disengaging the tail of a sheet from the slowdown sucker, preferably by having the blast work through the sucker mouth itself.

Other objects and features of novelty vwill appear as we proceed with `the-description of that embodiment of the invention which, for the purposes of the present applica'- tion, we have illustrated in the accompanying drawings, in which:

Fig. l is a sidel elevational view of a sheet delivery embodying the invention.

Fig. 2 is a plan view on a larger scale of the slowdown mechanism, taken looking in the direction of line 2 of Fig. 3.

Fig. 3 is an elevational view of the slowdown, taken looking in the direction of line 3 of Fig. 2.

Fig. 4 is a f-ragxnental elevational view on a still larger scale showing the suction plates and slowdownsuckers.

Fig. 5 is a sectional view taken substantially on the line 5 5 of Figs. 3 and 4.

Fig. 6 is a sectionall view taken substantially on the line 6 6 of Fig. 3 but on a larger scale.

I Fig. 7 is a sectional view taken substantially on the line 7 7 of Fig. 4.

Fig. 8 is a front view of driving gears, the view being taken substantially on the line 8 8 of Fig. 7.

Fig. 9 is a sectional view taken substantially on the line 9 9 of Fig. 3 but on a larger scale.

Figs. l0, 1l and l2 are diagrammatic views showing three different sucker positions.

Fig. I3 is a diagrammatic view showing four different positions of sucker movement and indicating the relative speed of movement of the sucker at different points in its travel.

Fig. 14 is a view partly in section of a rotary fourway valve for controlling the application of suction and compressed air to the sucker and a blowdown pipe, the view being taken substantially on the line 14-14 of Fig. 15, and

" Fig. 15 `is aisectional view showing the driving means 23 of a chain delivery as the bars move over a skeleton cylinder 21. One of the two delivery chains is shown at 22. Grippers on the gripper bars 23 take the sheets from the impression cylinder and carry them forward on the lower run of the chain conveyor until the gripper's are operated by a stationary cam 24 to release the sheets. The gripper bars are spaced apart a distance somewhat greater than the length of maximum sheet which the delivery is designed to handle. At about the time the forward end of each sheet drops onto the delivery pile 25, a sucker slowdown indicated generally at 26 takes hold of the tail end of the sheet while the sucker is traveling at or slightly above sheet speed. The sucker thereafter decelerates rapidly, slowing down the sheet movement suiciently to cause the sheet to settle quietly onto the pile.

The slowdown mechanism 26 is adjustable back and -forth as a whole to accommodate Ait to sheets of dierent lengths less than that of the maximum sheet for which the machine is designed. When once adjusted for sheets of a given length however, the major part of the slowdown mechanism is fixed and rigid.

The slowdown comprises two relatively fixed transversely disposed pipes 28 and 29 which are mounted at their ends in frame members 30 adapted to move back and forth for adjustment purposes upon tracks 31 and -32 which have racks on their lower surfaces engaged by pinions 33 and 34 which are xed to a transverse shaft 35 that canbe rotated manually by any suitable means for adjusting the whole slowdown mechanism. Upper and lower tracks 36, 37 are illustrated in Fig. 3, between which tracks each chain 22 runs for guiding its movement in at least the horizontal portion of its travel above the delivery pile. Y The frame of the slowdown 26 comprises two outer brackets 38 having holes therethrough for the reception of pipes 28 and 29, these brackets being attached to the pipes by suitable means. In addition there are two somewhat similar brackets 39 and 40 spaced apart a short distance and mounted on the pipes 28, 29 near the middle of the slowdown. On the upper ends of each of the brackets 39 and 40 and also of the brackets 38 there aro suction plates 41, each of which has a suction port 42 at its upper surface. As shown more particularly in Figs. 5 andv 6 these ports connect with passages 43 in the brackets 38, 39 and 40 and with the pipe 28 to conneet the bore of that pipe with the upper surfaces of the suction plates. On each of the brackets 39 and 40 there is a boss 45. A bar 46 extends through aligned openings in these bosses and is secured therein by setscrews illustrated in Figs. 4 and 5 to accurately space the brackets 39 and 40.

In bearings in the brackets 39 and 40 there are two short shafts 48, 49, one directly above the other. Each of these shafts projects a short distance beyond the brackets 39 and 40. These shafts have gears 50 and 51 keyed thereto between the brackets 39 and 40 in staggered relation. Both of these gears mesh with a wide gear 52. The latter gear is keyed to a drive shaft 53 which may be driven at one end by a gear 54 secured thereto and rotated in one to one relation with the press so as to turn once for each cycle. As indicated in Fig. 7 the gears 50, 51 and 52 are of the same diameter and the gears S and 51 turn in the same direction. Preferably the gears 50 and 51 are mounted upon or are integral with hubs 4 of a length to tit with only slight clearance between the brackets 39 and 40.

On short shaft 49 outwardly of the brackets 39 and 40 there are disks 56 secured to the shaft by keys and setscrews 57. Similarly on the short shaft 48 outwardly of the brackets 39 and 40 there are disks 58 secured to the shaft by keys and setscrews 59. The disks 56 and 58 are of the same diameter substantially as the pitch circles of gears 50 and 51. The two disks 56 are identical except for rights and lefts and the same is true of the two disks 58. Outwardly of the disks 56 and 58 on each side of the center there is a suction arm 6l), these arms being identical also except for rights and lefts. Each of these arms carries a resilient suction cup 61 preferably of rubber, at the upper end of the arm, each cup having a flat face or mouth and being connected by a passage 62 with a nipple 63 extending laterally outward at an intermediate point of the arm. Near its lower end each arm is connected with the adjacent disk 56 by a pivot 64 constituting a crank on the disk. On the inner side of each arm 60 there is a lengthwise guide groove 65 in which runs an antifriction cam roller or crank 66 carried on a stud 68 which passes through a reduced thickness portion 67 of the disk 58.

Spaced laterally outwardly a substantial distance from each of the sucker arms 60 there is a bracket 70 supported upon the pipes 28 and 29. Within each of these brackets and connected with the bore of pipe 29 there is a passage 71 which extends up toward the top of the bracket and connects with a nipple 72 mounted in the bracket and projecting horizontally toward the center of the mechanism. Between the nipples 63 and 72 on each side of -the center there lis a flexible conductor 73 by means of which the bore of pipe 29 is continuously connected with the passages 62 of the sucker arms throughout the movement of-those arms.

On the forward face of each bracket 70 there is a plate 75 with guide grooves on its sides which receive a plate 76 that constitutes a stop for the rearward edges of the sheets, these plates being movable vertically to a limited extent.

The shaft 53 is journaled in all of the brackets 38, 39 and 40. Adjacent each of the brackets 38 there are eccentrics 77 on the shaft which operate connecting rods 78 the outer ends of which are pivotally connected at 79 with jogger plates 80 which are pivotally mounted at 81 upon the brackets. The eccentrics are so disposed` angularly that directly after each sheet moves forward. the jogger plates swing toward the dotted line position of Fig. 6 to insure the proper positioning of the sheet against stops 82 at the front of the pile.

Mounted in the frame of the slowdown mechanism is an overhead pipe 83 which `may be termed a blowdownpipe and which has ports in its lower side from which air blasts may be discharged downwardly at timed intervals against the sheet to help to hold it against the suction plates 41 and toward the suckers 61. The upper pipe 28 is exposed to constant vacuum or suction through a connection 84 to lany suitable means for producing suction. Pipe 29 on the other hand is subjected to alternating suction and air pressure as is also pipe 83'.

This alternating effect of suction and pressure is accomplished by means of a rotary four-way valve having a casing 85 and a rotor 86. From the casing 85 a conductor 87 leads to a source of suction and an oppositely disposed conductor 88 leads to air under pressure. At right angles to conductors 87 and 88 there are two conductors 89 and 90, conductor 89 leading to pipe 29 while conductor 90 leads to pipe 83. The shaft 91 for operating the rotor 86 is driven byv suitable means, as by a chain running over a sprocket 92, at half the speed of the press. The rotor has two approximately semi-annular grooves 93 and 94. When it is in the position of Fig. 14 conductor 89, pipe 29 and the suckers are connected to conductor S7 and vac- .83. which are eiective at that time.

At-the same time air under pressure from conductor 88 passes out through conductor 90 to pipe 83to cause air blasts to impinge upon the sheet passing over the slowdown mechanism. When the rotor 86 is turned to a position at right angles to that illustrated in Fig. 14, conductor -89 will be connected to conductor 88 and air under pressure will thereby be ejected through the sucker cups. At the same'time suction will be conveyed from conductor 87 to conductor 90 and thence to pipe 83. The suction exerted through pipe 83 will perform no benecial action. However it will do no harm at that time.

To state briey the operation of the device, the suckers 61 move forward in a substantially vertical arc which touches the sheet path, grasp the rear end of the sheet while traveling at sheet speed or a trie faster than sheet speed, decelerate to substantially zero speed, discharge the sheet at substantially the forward end of the sucker travel and return at a level below that of the sheet path. The path of sucker travel is indicated in Fig. 13, where each dot in the loop indicates a point of travelV from the preceding dot. The points at which the air blast comes on and at which the suction comes on are marked in the ligure, being approximately 180 apart in timing, as called for by the rotation of the .rotor 86 -of therair and suction valve. That valve turns at one-half press speed and makes a complete reversal at every 9(1" angle. In other words there is an air blast Aperiod and asuction period in each 180 of rotation of the valve and in each complete travel of the suckers through their loop path. As indicated by the spacing of thedots in Fig. 13, the` forward movement of the suckers fromfthe rearmost position P. to the intermediate high position IH is atan accelerating rate. of speed until the top' of the arc is reached, and thereafter at a decelerating rate until the forward position F is reached, whileY in lthe, return travel the. sucker moves at a. relatively low rate of speed through its intermediate low. position lL back to position. R. i

.The arc of movement of the suckers in their forward travel preferably extends slightly above the surface of suction plates 41. The ports in plates 41 are continuously under suction from the pipe 28, which places a drag upon the sheet as. it isv pulled` forward by the grippers on a gripper bar 23. Movement of the suckers 61 is timed so that they take a sheet just as the tail end of sheet opens the ports42 in the. plates 41. The sheet therefore tensioned until the suckers 61 grip it. The gripping, is assisted by the blasts from the ports in pipe These blasts also assist the suckers 61 in graspingl the sheet. Since the suckers 61 move at sheet speed or faster when they come into. contact withsthe rear end of the sheet, there is. no sliding of the sheet on the suckers and hence no wear upon. them. After they thus firmly grasp the sheet. they are decelerated rapidly, slowing downthe travel of the sheet-as it moves into the desired position above the pile 25, the grippers on the gripper bar having been operated. in properly timed relation to release the sheet at about theV time the suckers take hold. Ther rotary valve is timed to cause an air blast tobe ejected from the suckers against the bottom. of the sheet, which insures its release from the suckers. While the air blast through the-.suckers is on, vacuum is present in the blowdown pipe 83,4 but it does no harm at that time and the blast in batck on again when suction is returned to the suckersV 61.

The successive positions of each sucker as it moves through its loop travel me illustrated in Figs. 5, 10, 11 and l2. The cranks 64. and 66 are positioned.v in their disks 56 and 58,l 180 apart angularly. In Fig. 5 crank 64 is at the bottom. and crank 66 at the top. Next they move to the positions of Fig.k 110 which points the sucker diagonally upward toward the. right. This requires about 135" of angular movement of the disks 56 and 58. The

il? parts then begin their movement -to the position of Fig. 11, when the cranks'64 and 66 are in vertical alignment. This requires an angular movement of the disks S6 and S8 through only 45 approximately. The suckers in that movement must therefore travel at a relatively high rate of speed. Similarly, in their decelerating movement from the Fig. 11 position to that of Fig. 12 the disks 5'6 and 58 move angularly throughanother 45 rotation, while in moving from the Fig. 12 `position to that of Fig. 5 the disks must turn throughanother 135 angle which means that the sucker vtravels slowly until it reaches the Fig. 5 position after which the cycle is repeated. Thus the desired rapid deceleration. in the forward upper part of the loop is accomplished'effectively by the simple mechanism illustrated.

Having thus described our invention, we claim:

l. in a sheet delivery slowdown, a sucker having a back and forth travel beneath the sheet path in a direction parallel to the direction of sheet travel,A means for exerting suction in the sucker at the time of taking the sheet, means for causing the sucker after it takes a sheet to move forward first in a downward arc while decelerating gradually and evenly to approximately zero speed, theny to move rearwardly at low speed and a different level, and then toV move forwardly again in an arc approaching the sheet path while accelerating gradually and' evenly to sheet speed approximately, means to break suction in said; sucker at about the time the forward movement of the sucker reaches zero and to resume suction in the sucker at the time. the sucker again moves forward to take the next succeeding sheet.

2. In a sheet delivery slowdown, a sucker traveling below the sheet in a generally horizontally elongated arc shaped loop having. upper forward and lower return runs, means for causing the sucker to take the sheet. during its forward run at approximately the top of said loop while traveling at sheet speed substantially, to decelerate to ap- Y proximately zero speedA at the front end of the loop,ft0 release the sheet, to return at relatively low speed through the lower run of said loop, to reverse its travel at the rear end of the loop to enter the upper forward run and to accelerate during that run to sheet speed prepara.- tory to taking the next succeeding sheet during the -next cycle of the machine.

3. A sheet delivery slowdownV as dedned in claim. l., comprising means for reversing the llow oi air through said sucker at substantially the forward end of its, travel to blow the sheet loose from the sucker mouth, and to expel foreign matter.

4. A sheet delivery slowdown according to claim 3, comprising a valve having, connections to. a source of vacuum and a source of compressed air., and having also an outlet to said sucker, and means for operating said valve once for each cyclerto connect the sucker with suction for enabling it to take. the sheet and for 'cutting oti suction` and directing compressed air into the sucker mouth when it reaches the. front end of its travel after being decelerated to blow the sheet loose, from thevsucke mouth and expel foreign matter. Y

5. l'n a sheet delivery slowdown, stationary suction platesf mounted below the path of sheet travel, adapted to tension a sheet, means for drawing the sheet forward over the platesonto a delivery pile, said plates each having a snctionport therethrough thatV is uncovered as thetail end ot'V the sheet passesv over it, a plurality of previously activated suckersY disposed beneath the sheet path which rise into proximity with the tail of the sheet as it clears saidsuction port-s in the suction. plates, means for moving the suckers forwardly at approximately sheet speed at the time they approach and grip the tensioned sheet and then decelerating rapidly butA gradually and evenly to slow down the sheet,.and means for braking the. suction to the suckers thereafter to cause the. sheet to settle on the delivery pile.

6. A sheet delivery slowdown as defined in claim 5 com- Y prisingV means for causing the suckers at the .timethey take a sheet totravel forward at a level above the"level means VVincluding eccentrics on saidY shaft for swinging Y 1saidijogger',platesrback and forth `during each'cycle.

'8.In'a1sheetdelivery slowdown, a* sucker arranged: to engagegthe Vtail end of asheet and dccelerate the sheet continuously and progressively from sheet speed to zero speed Vto cause. it to drop quietlyVv onto Va delivery pile,"a suckerarm carrying said sucker at its upperend, and

ln1ea`i'1s`for moving said sucker forwardfat a high levelV andrearward at a lower level comprising a pair of disks mounted one vabove the other for rotation about their axes, saidsucker'arm having a uid connection intermedi- Y moving forward atV sheet'spee'd to lgrasp the tailgend-y of Y ,claim i3, comprising means for eausingfa blast. vofairfto be `ejected through theY sucker mouthv at the forwarden'd of the sucker movement after the suction isfctmotY to Y ate'its ends and a lengthwise guide, the lowerdisk having f' a crank connected with the Vlower 'end of saidsucker arm and the'upper.v disk VVhaving a crank slidable withinV said lengthwise guide,` and means ifor rotatingsaid disks in `the saine direction .at the same speed l V9.`A sheet delivery slowdown as defined in'claim 8, V comprising'means for causing both cranks simultaneously to be disposed in the verticalplane angularly spacedj180 twice foreach cycle, and for causing the sucker when movingforward'at said high level to accelerate and de- `celerate rapidly and when moving rearward .at Ysaid lowerv Y level to travel ata relatively slow rateof speed. 10. In V a sheet delivery slowdown, two stationary brackets spaced vapart transverselyof the sheet path, a pair of Y jupper and lower disks rotatably mounted one .above the other. in said brackets on the outer side of each bracket, y,

Yrneans between said brackets for rotatingY all of said-disks,-

continuously'in the same direction at the same rate ofV i jsp'eedya` sucker.V arm disposed outwardlyof'each pair of disks, each sucker armfhaving a sucker mouth atvits n upper end and having a lengthwiseguide groove, each lowerV disk having a crank connectedwith therlower end of the; adjacent sucker arm and eachupper diskfhaving a crank'slidablewithinrthe lengthwise guide Vgroove of Vthe adjacent sucker'arm, said arms having fluidV passages leading Vto theirVV respective suckermouths,tieXible-conductors ,leading to said passages, the cranks' of the upper disks and the cranks of the 'lower disks being oppositely Y .disposed andangularly spaced 180 ywhen they stand in Vvertical planes, whereby the suckers move at a high level inone .direction while accelerating and decelerating V"rapidlyand, move relativelyslowly at aV lower level in the Vopposite direction.Y e

l1. A sheetgdelivery slowdown as Ydefinedv inrclaim Yl0,

vcomprising a fixed transverse pipe, a second setof brackets Y vmounted ,thereon spaced laterally from said iirstnamed brackets, the outer'endsof Vsaid ilexible conductors being operatively connected through vsaid second brackets with vthe bore of said pipe, and means for inducing suction Ain said pipe once` for each cycle.

v1,2,."A sheet deliveryV slowdown as deiined'in claim` 170,'y

. whereineachof said brackets has va'horiz'o'ntal suction Y plate'at its'upper end and wherein said suckers in traveling forward move through an arcextending at one point slightvrly aboverthe'surfaces Vof saidsuctionplates, comprising AVtwo fixed transverse pipes upon whichsaid brackets are tally spaced suction plates havingjat upper surfaces'con- Yr taining suction openings, gripperswadaptedlto graspethe forwardV end' ofY each 'sheet and drag itI forward yover 4said suction plates', atleast one sucker disposedbe'neath the sheet Ypath and'between saidsuction plates adapted while the sheet just before ity leaves said suction plates, meansvfor causing the Vgrippers tore'leas the sheet, and means for deceleratirig the sucker continuously and progressively vfromcsheet speed to zeroY speed and cutting ot its'suction to release the sheetv and for. causing'the suckerrt'o move Y Y rearwardly at`a lower level when said Vzeroespeped is Y `reached preparatory to again rising and movingf'o'rward totake the next succeeding sheet."

14. A f delivery f slowdown substantially kas l defined release the sheetand blow'it upwardly'from the, sucker mouth.

l5. In a pile delivery mechanism, conveyingineansj :Y passing overa pile of sheets, sheet grippers carried ,by said conveying means adapted toreceive sheetsv from a sheet handling machine and transport them inV a generally ho'rifV zontallpathabove the top -of said pile, sheet slowdown means adjacent the 4top of thepilealong that'edgeth'ereof from whichfsheets' conveyed to the pile approachgfsaid slowdown means comprising a rubber suckerrv moving `atsheet speed substantially whenit vtakes the sheet,- Ar'neans Y intermittently Y'communicating suction thereto, and means moving said suckerY in the direction of sheet travelin a Y path atleast a portion .of'which generally coincides'w'ith the i sheet path, said sucker `taking hold of the tailV of 'a sheetwhile the paths generally coincide and while the forwardfend of the sheet is held by the, sheet grippers, means Yoperating thejsheetV grippers to release the sheet -`after-f the suckerV has taken it, said sucker moving meansibeing,

' operatedaat a varying speedrand deceleratingto a' speed near zero speed to decrease theV speed of thesheet held thereby and being adapted upon release of suction to said Y sucker `to reverse the direction of travel of said sucker.

Y down means adjacent lthe 'top `ofthe pile along that edge 16. Mechanism accordingY to claim=15 whereinair pressure creating lmeans is provided and wherein air'under pressure is'communicated to said sucker upon releaseof a sheet whereby the air Vpressurefejects the sheet l'and maintains it spaced fromthe sucker as the sucker'beg'ins Vits reverse travel.

`17.*InV a pile delivery mechanism, conveying means` passing over a pileof sheets, sheet g'rippersrcar'ried by saidconveying means adapted to Yreceive'sheets from a sheet handling machine and V transport them'in a generally horizontal path abovethe top of said pile, lsheetrslow-Y thereof ,from which sheets approach the pile, ,said slowdown means comprising a pair of Vsuckers Vengageable with the tailv of each sheet, meansl intermittently communicat-Y Y ingsuction'tosaid suckers, meansrincluding a rotating supported'said brackets having passages extending'from Y the bore' of Ythe first of said pipes to the surfaces of said suctionplates, the outer ends of said flexibleconductors being operatively connected with the bore ofthe second pipe, vmeans for maintaining suction continuously in said iirstpipe and means for inducing suction and pressure alternately in said second pipe'during each cycle.V

i Y 13. ,In a sheet delivery slowdown, a pair of horizon- 'shaft on'a iixedaxis operativelyYV connected to and Fcarusing oscillation of said suckers inthev direction Vof sheet travel -in a path at least a portion ofY whichg'e'nerally Y coincides With thesheet path, said'sucker-taking hold Yof the tail'of a sheet while -it'isjheld by the sheet grippers, 'Y 'means'operating thesheet grippers to release theg'sheet Vafter it has been taken by the suckers', ajo'gger plate Yen- Y gageable with that edge of the pile'adjacent the slowj down means and extending above and below Ythe topof the VVpile, .and means Yoperatively connectingl the joggen'V plate and the rotating shaft forimoving said jogger plate,V Y into'engagement with'the Vpilejafter'release of asheet byV said suckers whereby said sheet is brought into v`alig'rnnent with the remaining sheets on said pile.

18.V A piledelivery mechanism according to claim ".17 j

wherein the meansV for moving the joggerV plate comprises' aneccentric carried on said rotating shaft, VVand a connect# 'ing rod iutermediatesaid eccentric and saidjogger'plate.

19. n a pile delivery mechanism, conveying means passing over a pile of sheets, sheet grippers carried by said conveying means adapted to receive sheets from a sheet handling machine and transport them in a generally horizontal path above the top of the pile, sheet slowdown means adjacent the top of the pile along that edge thereof from which sheets conveyed to the pile approach, said slowdown means having vacuum communicated thereto and being operated to grip sheets with vacuum on their undersides, decelerate them continuously and progressively from sheet speed to zero speed, and assist in depositing them gently upon the top of a pile, and valve means connecting the slowdown means irst to a source of vacuum while slowing down a sheet and then connecting the slowdown means to a source of air under pressure to expel any foreign matter gaining entrance into the slowdown means or connections thereto, and to disconnect the sheet from the slowdown means as the latter begins its reverse travel.

20. Mechanism according to claim 19 including an air pipe spaced substantially vertically above the slowdown means and transverse to the sheet path, said air pipe being connected to said valve means and having ports along its length directed toward the slowdown means in order to impinge air under pressure toward said slowdown means to assist holding sheets held thereby against the slowdown means, said valve means comprising a rotor having two diametrically opposed circumferential slots on it speriphery each extending at least 90 therearound and both lying in the same plane perpendicular to the axis of the rotor, a valve casing having a cylindrical opening for the rotor, a connection from the source of air pressure to the cylindrical opening, a connection from the source of vacuum to the opening but spaced therearound 180 from the air pressure connection, the connections to the slowdown means and to the air pipe being diametrically opposed and at right angles to the air pressure and vacuum connections, all of said connections being in the path of movement of said slots whereby when vacuum is communicated to said slowdown means air pressure is communicated to the air pipe, and when air pressure is communicated to the slowdown means vacuum is communicated to the air pipe.

21. The method of depositing sheets onto the top of a pile thereof, comprising the steps of gripping and moving sheets in a generally horizontal path spaced above the top of said pile, moving a rubber suction mouth in the direction of sheet travel in a path at least a portion of which generally coincides with the sheet path, taking hold of the tail of a sheet with the suction mouth while the paths generally coincide and while the speed of the mouth is at least as great as sheet speed, releasing the initial grip on the sheet, decelerating the speed of travel of said mouth continuously and progressively to gradually decrease the speed of the sheet held thereby to zero speed, releasing the hold of said mouth to release the sheet and permit it to settle onto the pile, and returning the suction mouth to its original position while relatively separating the sheet and suction mouth paths during such return to prevent said resilient suction mouth from dragging on the next sheet to be deposited.

22. The method according to claim 21 including the Step of maintaining the sheets in their path by supporting them from below and applying a jet of air from above at least during the time the suction mouth takes the sheets.

23. 'Ihe method of depositing sheets onto the top of a pile thereof comprising the steps of gripping and moving sheets in a generally horizontal path spaced above the top of said pile, moving a rubber suction mouth in the direction of sheet travel in the path of an arc having acceleration to the middle point of the arc and then deceleration, at least a portion of the sucker path generally coinciding with the sheet path, taking hold of the tail of a sheet with the suction mouth while the paths generally coincide, said suction mouth traveling at a speed slightly faster than sheet speed during such taking, releasing the initial grip on the sheet, decreasing the speed of said mouth to gradually and evenly decrease the speed of the sheet held thereby continuously and progressively to zero speed, releasing the hold of said mouth to release the sheet and permit it to settle onto the pile, and returning the suction mouth along a path removed from the sheet path to prevent engagement of said mouth and the next sheet to be deposited.

24. 'I'he method according to claim 23 including the additional step of providing a jet of air from said suction mouth as each sheet is released by the mouth to eject said settling sheet to prevent its dragging across the suction mouth as the latter begins its return stroke.

25. The method of depositing sheets onto the top of a pile thereof, comprising the steps of gripping and moving the sheets in a generally horizontal path above the top of said pile, moving a pair of rubber suckers in the direction of sheet travel in a substantially vertical arcuate path below the sheet path and tangential with the sheet path, connecting said suckers to a source of suction, taking hold of the tail of a sheet with the suckers when the sheet and sucker paths coincide at said tangential point, releasing the initial grip on said sheet, reducing the speed of travel of said suckers gradually and evenly to decrease the sheet speed continuously and progressively, disconnecting the suckers from the suction source and connecting them with a source of air under pressure when the speed of the sheet has been reduced to a speed near zero to cause said suckers to eject the sheet and simultaneously clear the suckers of any foreign matter, and returning the suckers along a path removed from the sheet path to prevent engagement of said suckers and the next sheet during such return stroke, and the first part of the forward travel of the suckers before they grasp the next sheet.

26. The method according to claim 25 including maintaining the sheets in their path by supporting them from below and applying an air jet from above at least during the time the suckers take the sheet, and producing suction in the sheet supports to create a drag on the underside of each sheet and thereby maintain the sheets relatively taut for facilitating taking by the suckers.

References Cited in the file of this patent UNITED STATES PATENTS 2,106,199 Wormser Jan. 25, 1938 2,130,841 Eckhard Sept. 20, 1938 2,167,470 West July 25, 1939 2,282,224 Harrold May 5, 1942 2,657,052 Elliott Oct. 27, 1953

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