US3595564A

US3595564A - Apparatus for handling sheets

Info

Publication number: US3595564A
Authority: US
Inventors: Raymond J De Young
Original assignee: North American Rockwell Corp
Current assignee: Boeing North American Inc
Priority date: 1968-05-15
Filing date: 1968-05-15
Publication date: 1971-07-27
Anticipated expiration: 1988-07-27

Abstract

Apparatus for successively cutting a plurality of similar sheets from the leading end of a web which is being fed forwardly, the apparatus including means for pulling the sheets forwardly from the cutting station, means for forming the travelling sheets into a shingled stream of sheets with the leading end of each sheet overlying the trailing end of the previously fed sheet, means for turning the thus shingled sheets over while they continue their travel, and means for forwarding the turned over shingled sheets to a stacker which is fed from the bottom of the stack. The apparatus of the invention is so constructed that it can be readily adapted to the handling of sheets of different lengths.

Description

D United States Patent llll 3,595,564

[72] Inventor Raymond J. De Young 2.172.646 4/ N45 Barnby l98/l65 Woodctifl Lake, NJ. 2.852.256 9/1958 Faulls 27l/74 [2| I Appl No 729,191 1255.652 b/l966 Linden 83/88 :3: I giled d M ay FOREIGN PATENTS atente .Iu y r In] Assign Norm American Rockne" Corporation l,056,497 l/ I967 Great Britain 271/74 Pittsburgh, Pa. Primary ExaminerRichard E. Aegerter AttorneysDale A. Bauer, .lohn Lv Seymour and Bauer and Seymour [54] APPARATUS FOR HANDLING SHEETS 2] Claims, 12 Drawing Figs.

U.S. t v t t a t Ap aratus for successively culling 3 pluralhy of 33/88 similar sheets from the leading end ofa web which is being fed l llli- CI a r r r r r 365k forwardly, the apparatus including means for pulling the 1365b 29/12 sheets forwardly from the cutting station, means for forming l Search 27l/3. v the travelling sheets into a shingled stream of sheets with the lov45- 75, 79; gs/I65; leading end of each sheet overlying the trailing end of the 226/193; 33/88 previously fed sheet, means for turning the thus shingled sheets over while the continue their travel, and means for for- [561 Rem-mm and warding the turned gver shingled sheets to a stacker which is UNITED STATES PATENTS fed from the bottom of the stack. The apparatus of the inven- 2,498,06l 2/ I950 271/76 tion is so constructed that it can be readily adapted to the han- 2,Bl9,079 1/ i958 Beaulieu r. 271/76 dling of sheets of different lengths.

PATENTED JUL27 IEIYI SHEET 1 0F 6 PATENTED JUL27 IQTI SHEET 2 BF 6 INVENTOR Raymond J. De Young BY 3M amd/ ATTORN 5 PATENTEH JUL2 1 IQTI SHEET 3 OF 6 INVENTOR Raymond J. De Young BY 5w $551M PATENTEB JULZ'IISTI 3,595,564

SHEET l 0F 6 INVENTOR soymond J. De Young amamd J ATToRi Zg PATENTEUJUL21 ism SHEET 5 BF 6 q R Q INVENTOR Raymond J. De Young BY MMJ ATTOR YS PATENTEUJULZTIHYI 3,595,564

sum 5 or 6 INVENTOR Raymond J. De Young APPARATUS FOR HANDLING SHEETS This invention relates to an apparatus for handling sheets of paper. More particularly. it relates to an improvement upon the apparatus disclosed and claimed in the patent to Linden. U.S. Pat. No. 3.255.652. issued June 14, I966, which is assigned to the assignee of the present invention. In such prior apparatus. a web of material such as paper is fed to a shearing means so as to cut sheets of predetennined length from the leading end of the web. The tltus cut sheets are first conveyed at high speed in sequential. spaced relationship away from the shearing zone. and are then slowed in their travel so that they are brought into overlapping, shingled relationship while travelling in the some direction. The sheets are slowed from their initial high speed to their subsequent slow speed by being dropped from a first. upper. high-speed conveyor onto a second. lower, low speed conveyor. The successive transfer of sheets from the first to the second conveyor causes the leading end of a subsequently fed sheet to overlap the trailing end of the last previously fed sheet.

In the described prior apparatus. first the leading end of the sheet, and then progressively more and more of the intermediate portion of the sheet rest upon the lower speed conveyor. while the remainder of the sheet rests upon the highspeed conveyor. This causes the sheet to tend to wrinkle or bunch up. since the trailing end of the sheet is travelling at a higher speed than its leading end during the time that the sheet is being transferred from the first to the second conveyor. Such tendency of the sheets to wrinkle is particularly pronounced when the sheets are of light. thin stock.

The apparatus of the present invention overcomes such difficulty. It effects the transfer of sheets travelling at a high speed on one conveyor to a low speed on another conveyor by grasping the leading end of a sheet by an upper. high-speed conveyor. and by permitting the trailing end and intermediate portions of the sheet progressively to fall upon a lower. slowspeed conveyor while the leading end of the sheet remains grasped by the high-speed conveyor so as to travel therewith. Upon the releue of the leading end ol'the sheet from the highspeed conveyor. periodically actuated presser members such as rolls engage the leading end ofthe sheet to reduce its speed to that of the low speed conveyor. thereby reducing the tendency of the sheet to wrinkle. and allowing the sheet to flatten to remove any wrinkles which may have formed in it.

The apparatus of the present invention is also capable of handling sheets having lengths which vary over a very substantial range. the machine requiring only a few simple adjustments when the length of sheet to be processed is changed. As a result. the machine of the invention may be quickly and accurately changed to form and handle sheets of different lengths.

The invention has among it objects the provision of an improved. more facilely adjusted and operated apparatus for forming sheets of various lengths by shearing them from the leading end of a travelling web. forming them into a travelling stream of sheets in shingled relationship with the leading end of each sheet overlying the trailing end of the previously fed sheet. and turning the shingled sheets over while they travel in the direction of their lengths.

Another object of the present invention is the provision. in a machine of the described character. of improved mechanism for slowing sheets from a first, higher speed to a second. slower speed in such manner as markedly to reduce the tendency of the sheets to wrinkle.

A further object of the invention is the provision. in the above-indicated combination. of mechanism whereby sheets of various desired lengths may be more effectively formed and handled while maintaining the speed of the web-shearing means constant.

A still furtberobject ofthe invention is the provision. in the described apparatus. of a first conveyor downstream of the shearing mechanism. which may be adjusted to vary the Ion gitudinal position of its grasping the leading end of a sheet. a

second conveyor. fed by the first conveyor. and means for varying the timing between the first and second conveyors as required by different lengths of sheets being processed.

Yet another object of the invention is the provision of a novel second conveyor having sheet-grasping means wherein the position of such sheet-grasping means thereon may be adjusted in accordance with the length of sheet being handled.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood. however. that the drawings are for the purpose of illustration only. and are not intended as a definition of the limits of the invention.

In the drawings. wherein like reference characters refer to like pans throughout the several views.

FIG. I is a schematic view in side elevation of apparatus in accordance with the invention, the figure showing means for feeding a web. means for cutting off the leading end of the web to form sheets. and sheet handling and conveying mechanism in accordance with the invention;

FIG. 2 is a view in side elevation of the sheet handling and conveying portion of the system of FIG. I;

FIG. 3 is a view in plan of the apparatus shown in FIG. 2;

FIG. 4 is a fragmentary. somewhat schematic exploded view in perspective of the apparatus shown in FIGS. 2 anda. thc figure also showing schematically the means for driving and adjusting the conveyors of the apparatus relative to the webleeding means. the apparatus shown in the main being that above the section line 4-4 of FIG. 3;

FIG. 5 is a view in perspective of one of the oogged belts of the second, upper high-speed conveyor ofthe apparatus;

FIG. 6 is an exploded view in perspective of the portion of the apparatus which lies upwardly beyond the section line 6-6 of FIG. 3. certain of the parts of the apparatus being broken away;

FIG. 7 is a fragmentary view partially in end elevation and partially in vertical transverse section of the portion of the apparatus in the vicinity of the turnover roll. the section being taken along the broken section line 7-7 of FIG. 3;

FIG. 8 is a view in vertical section through the first. high speed conveyor at the nip-forming mechanism therein. the section being taken along the line 8-8 of FIG. 3. certain of the parts being shown in elevation;

FIG. 9 is a fragmentary view in vertical longitudinal section on an enlarged scale through the apparatus in the vicinity of the exit end of the first conveyor and the entrance ends of the second high speed conveyor and of the third, low speed conveyor. the section being taken along the line 9-9 of FIG. 3;

FIG. 10 is a fragmentary view in vertical longitudinal section through the apparatus in the vicinity of the exit end of the second. upper high speed conveyor and of the drop rolls which overlie the turnover roll. the section being taken along the line 10-10 of FIG. 3;

(For simplicity of illustration. only one sheet being fed is shown in FIGS. 9 and 10.)

FIG. 11 is a fragmentary view in vertical transverse section through the apparatus and showing the manner of support of the rear end of a vacuum chamber from the vacuum manifold, the section being taken along the line "-1! of FIG. 9; and

FIG. I2 is a fragmentary view in vertical longitudinal section through the apparatus at the location of one end of the nip forming device associated with the first conveyor. the section being taken along the line 12-12 of FIG. I.

GENERAL CONSTRUCTION AND OPERATION OF THE APPARATUS The general construction and manner of operation of the apparatus of the invention will best be understood by referring to FIG. I, wherein the apparatus is schematically shown. In such figure. a web of material to such as paper is fed from a supply roll ll thereof through variable-speed feeding means II which is shown as including opposed pinch rolls which are driven by a constant-speed motor 13 having a drive shaft [4 through the medium of a variable-speed gearing :ievice IS. The device I5, once adjusted. holds the w -rewarding speed of the feeding means I2 within close l mits. The supply roll I] may be provided with a brake eonnolled by a dancer roll engaging the web in advance ofthe feeding means l2. Between the feeding means 12 and the supply roll I]. the web may travel through a conventional decurler section. Since the webtensioning means and decurler section are well known and are not part of the present invention. they are not here illustrated.

The web-feeding means 12 forwards the web to a shearing means to which in this instance has a fixed bed knife [7 and a rotary knife cooperating therewith, knife 20 being mounted upon a rotatable knife support l9 which is driven at constant speed by motor shaft 14, as schematically indicated. The knife support [9 isspaced from the fitted bed knife 17 sufficiently for the web I0 to travel freely therebetwcen except when it is being engaged and sheared by the knives I7, 20. Thus the length ofsheet 26 which is cut from the web 10 by the shearing means is determined by the speed at which the web is forwarded to the sear by the web-feeding means I2.

The leading end of the web is graspingly engaged by a first conveyor 2] which travels at a speed which is substantially greater than that of the speed of travel of the web 10. Conveyor 2|, which has an upper belt made up of a plurality of laterally spaced tapes 23 and a lower belt made up of a plurality of tapes 24 disposed in the longitudinal planes of the respective tapes 23, is provided with a longitudinally adjustable device which determines the position of the nip between the upper and lower tapes at which the leading end of a sheet is initially grasped by the first conveyor. Means 25 is adjusted so that the first conveyor 21 grips the sheet 26 at the instant that the shearing operation by which the sheet is cut from the web is completed. As is set forth in the detailed description to follow, the nip between the tqses 23 and 24 of the upper and lower conveyors is not necessarily located exactly at the nipadjusting device 25; the nip may, for example, be at the location where the upper belts sag into substantial contact with the lower belts.

Alter being initially positively grasped by the conveyor 21 rt the location of the nip-forming means 25, sheet 26 is fed forwardly in flat condition between the

tapes

23, 24 and at the same speed a such tapes into the rear or entrance end of a second, upper conveyor 27 which is aligned with conveyor 21 and which travels at the same speed as conveyor 2| Conveyor 27 is provided with an upper belt which is actually composed of a plurality (three shown) of equally laterally spaced cogged or timing belts 29. Each of the belts 29 is disposed at the bottom of an elongated longitudinally disposed vacuum chamber 95 so as substantially to seal the open lower end of the chamber. Each belt 29 is provided with at least one vacuum operated sheet-grasping station thereon which is so located longitudinally of the belt as to grasp the leading end of a sheet 26 which has been forwarded thereto by the conveyor 2|. The belts 29 of the second conveyor are spaced somewhat vertically above the upper surface of the tapes 32 of a third, slowspeed conveyor 30 so that the leading end of the sheet 26 grasped by the belts 29 is elevated and the trailing end thereof sags downwardly into engagement with the tapes 31, as is illustrated in H0. 10.

As the sheet 26 reaches the forward end of the effective length of the vacuum belts 29, the grasping of such leading end a terminated by cutting of! the vacuum thereto so that the sheet as a whole falls downwardly upon the stream of sheets upon the tapes of the third slow-speed conveyor 30. The speed of conveyor 30 may be. for example, a small fraction of the speed of

conveyors

21 and 27. As a result, subsequently fed sheet. as its forward end is rdeased by the second conveyor 27, will be deposited upon the previously fed sheet with the leading end of the later fed sheet overlying the trailing end of the previously fed sheet.

The tapes 32 of the lower, slow-speed conveyor 30, at their forward ends pas partially about a relatively large diametered turnover drum 34. The thus shingled sheets, which continue to travel forwardly and now form a stream of sheets designated 38, pass to and partially around drum 34, the stream being generally retained against the tapes 32 running over the drum by nrcuate outer guides 33 (FIG. 2) spaced from the drum.

in order both positively to feed the stream of sheets in synchronism with the turnover drum and to relieve the sheets of wrinkles which may be caused by their handling by th previous conveyors and/or the shingling operation on th slow-speed conveyor 30, there is provided a plurality of idle drop rails 36 (three shown) which are spaced equally laterally of the conveyor 30 and cooperate with the turnover drum 34 and the tapes 32 entrained theneover which form parts of the third conveyor 30.

The drop rolls 36 are all affixed to a cross-shaft so as to move a: the same time and in the same manner with respect to the turnover drum 34. The cross-shaft mounting the drop rolls is operated by a cam and cam follower means generally designated 37, the cam being driven in synchronism with the conveyor 27. Such cam is of such configuration and so oriented with respect to the driving train for the apparatus that the leading end of a sheet 26 travels between the nip of the drop rolls and the turnover drum, the drop rolls then being in raised position to allow the leading end of the sheet to pass freely into such nip. The drop rolls are lowered to engage the sheet just rearwardly of its forward end so as to slow the sheet, which is still travelling at a relatively high velocity, to the slower speed of the tapes 32 at the turnover drum 34. Because of such rapid decrease in velocity of the sheet. parts of the sheet rearwardly of the nip between the drop rolls and the tapes 32 at the drum are apt to wrinkle. The drop rolls are now lifted to free the sheet and to allow whatever wrinkles that have formed in it to smooth out. The drop rolls again are lowered so that the forward end of conveyor 30 drives the stream of shingled sheets 38 around the turnover drum and down a further, inclined conveyor 39 to a stacking station 40. The drop rolls remain in lowered position until the leading end of the next sheet approaches them.

At such stacking station there are provided a horizontal conveyor 4! and an end stop 42. The turned over shingled sheets forwarded to the stacking station have the trailing end of the first or uppermost sheet overlying the leading end of the next sheet. The continual travel of the conveyor 40 toward the stop 42 causes the sheets to be formed into a stack 44 which is continually replenished from the bottom. the sheets in the stack being edge aligned by the end stop 42. Such stack 44 has its upper end free for the removal of the uppermost sheet therefrom as by engagement with such sheet of a vacuum feeding means such as that shown in the above-referred-to Linden patent.

DETAILED DESCRlFI'lON OF THE SHEET-HANDLING APPARATUS Turning now to FIGS. 2-4, inclusive, it will be seen that the illustrative apparatus is provided with two parallel, laterally spaced, horizontal longitudinal

side frame members

45 and 46 which are mounted on suitable supports (not shown) and held in spaced relationship by a number of crossmembers connected to them. In the embodiment shown, the first conveyor 2| is disposed at the left and the

conveyors

27 and 30 are disposed at the right, the sheets 26 being formed and processed travelling from left to right. Such conveyors, as well as further conveyors to be described, are driven from the motor shaft [4 (FIG. 4). the drive proceeding from a sprocket on the motor shaft to a first gearbox 50 through the medium of a chain 5t which is entrained over a sprocket $2 on the driven input shaft 53 of the gearbox S0. A clutch 49 adjustably connecta the sprocket 52 to the input draft 53 of gearbox 50; when the clutch is disengaged, the conveyor system thcrebeyond may be manually adjusted to bring the vacuum shut-grasping station: 146, I47 on belts 29 of conveyor 27 into the correct position relative to the web-feeding means I2 to permit the apparatus to handle sheets 26 of the desired length. Connected to the output shaft of the gearbox 50 through the medium of a coupling as shown is a longitudinally extending drive shaft 54 which is journaled in pillow blocks affixed to the frame member 46. Shaft 54 drives a second gearbox 55, such gearbox having a driven shaft 56 which is connected by a coupling 57 to the end of a cross-shaft 59 which drives the upper tapes 23 of the first conveyor 21. The coupling 57, as well as a gear 62 which is afiixed to the shaft 59, is disposed outwardly of an arm 60 which is secured to the inner face of the frame member 46 and carries a bearing in which such end of the shaft 59 is journaled. Keyed to the driven shaft 59 and uniformly spaced from each other along its length is a plurality of pulleys 61 over which the forward ends of the upper tapes 23 of the conveyor 2| are entrained.

The gear 62, as more clearly shown in FIGS. 2 and 4, meshes with an idle gear 64 which, in turn, meshes with a similar idle gear 65, both such gears being journaled upon stub shafts projecting laterally inwardly from the frame member 46. Gear 65 meshes with a gear 67, the latter gear being affixed to a cross-shaft 66, which is disposed below and forwardly of shaft 59 and which drives the lower belt or plurality of tapes 24 of the lower portion of the conveyor 2|. It will be seen that the

gear train

62, 64, 65, 67 causes the shaft 66 to rotate in the opposite direction from shaft 59. The tapes of the upper and lower portions of conveyor 2| travel at the same speed in the sheet-feeding direction, from left to right as the apparatus is shown in FIGS. |4, inclusive.

The

tapes

23, 24 constituting the upper and lower belts of conveyor 21 are entrained at their left-hand ends over

pulleys

70 and 73 on the upper and lower shafts 71 and 72, as shown in FIGS. 2 and 3.

Pulleys

70 and 73 are both in the form of elongated rolls which are journaled on their supporting shafts 71 and 72 by bearings interiorly of the rolls. Such shafts are held from rotation and affixed to the

frame members

45 and 46 and thus constitute cross tie members holding the

frame members

45 and 46 together. Because the

tapes

23, 24 constituting the upper and lower belts of the conveyor 21 are driven by the pulleys 61 and 69, the confronting, sheet-feeding runs of such tapes are pulled forwardly and thus are maintained under tension and free from wrinkles. The conveyor 2| may be provided with tighteners (not shown) for the

tapes

23 and 24, such tighteners engaging the runs or reaches of the tapes which are opposite the confronting, sheet-engaging runs thereof.

As shown, the upper, operative run of the lower tapes 24 of conveyor 21 is flat and horizontal and extends somewhat to the left of the left-hand ends of the upper tapes 23. Such lefthand end portion of the lower tapes is disposed close to the delivery end of the sheet-forming cutter 17, 20 so that the leading end of the web, which subsequently becomes a sheet 26, enters smoothly onto the lower tapes 24 of the first conveyor 21. The lower run of the upper tapes 23 upon leaving the pulley 70 travel downwardly to the nip-forming means 25 so that there is formed a V-shaped space converging to the right between such runs of the tapes; this permits the leading end of the web being cut to enter freely between the upper and

lower tapes

23, 24.

As above stated, the nip-forming means 25 is adjustable longitudinally of the conveyor 21, so that the operative runs of the confronting

tapes

23, 24 of conveyor 21 may grip the lead ing end of the sheet being formed at substantially the instant that the web-cutting operation is completed. The nip-forming means 25, which is particularly shown in FIGS. 4, II, and 12, includes a lower cross-shaft 74 which extends between

frame members

45 and 46 and outwardly through a horizontal longitudinally extending slot 75 in the frame member 45. An elongated roll 76, which is joumaled upon the shafi 74 by bearings disposed interiorly of the roll, constitutes the lower pinch roll of the nip-forming means 25. The roll 76 is of such diameter and the other parts are so constructed and arranged that the upper run of the lower tapes 24 of conveyor 21 just engages the upper surface of the roll 76 as such run of the tapes travels horizontally from left to right. A second horizontal cross-shaft 77 disposed above and parallel to the shaft 74 has journaled thereon a second, upper roll 79 which constitutes the second pinch roll of the nip-forming means 25.

As shown in FIGS. 4 and 8, roll 79 lies above the lower operative run of the upper tapes 23 of conveyor 2|. The ends of the

shafts

74 and 77 are carried by the longitudinally adjustable housings 80, in the manner shown in FIG. 8, the upper shaft 77 extending through vertical slots 83 in the housings. Vertical screws 81, the lower ends of which are threadedly connected at 82 to shaft 77 as shown in FIG. 12, pass freely through vertical holes in the upper end of the respective housings 80. Nuts 84 on screws 81 overlie the upper ends of the housings 80. The shaft 77, and thus the roll 79 thereon, are thrust by gravity toward the lower roll 76. The lower terminus of travel of shaft 77 and roll 79 is adjusted by screwing the nuts 84 along the screws 8| so that the nuts support the shaft 77 and roll 79 in the desired vertical position.

As above pointed out, the sheetengaging nip between the upper and

lower tapes

23, 24 need not be located exactly at the rolls 76, 79, but may, if desired, be disposed somewhat downstream from such rolls. Thus the nuts 84 may be adjusted, if desired, so that the confronting surfaces of the

tapes

23, 24 are almost in contact but are spaced slightly apart at the location of rolls 76, 79, the tapes converging to the right, as the upper tapes sag toward the lower tapes.

The housings are adjusted longitudinally by means including elongated rack gears 85 which are fixedly mounted upon the

respective frame members

45 and 46, there being a spur gear 86, received in a recess in the respective housing 80, affixed to the shaft 74 and meshing with the respective rack gear. Thus the housing is provided with a generally circular recess which receives the spur gear 86, and with a groove 9| which receives the rack gear 85. The shaft 74 is turned by a hand wheel 87, which is splined to and slidable axially of shaft 74, thus to drive the housings 80 in the desired direction longitudinally of the apparatus to adjust the nip between the upper and lower tapes 23, 2A of conveyor 2| either to the right or left. The housing 80 are held in such adjusted position by a lock wheel 89 which is threadedly mounted upon the outer end of shaft 74, wheel 89 when tightened thrusting a washer interposed between wheel 87 and the outer surface of frame member 45 against the frame member to lock the shaft 74 against rotation.

As disclosed above, the second conveyor 27 is disposed forwardly or to the right of the first conveyor 21. Conveyor 27 is constructed as follows. A vacuum manifold 92, which in the embodiment shown is of rectangular section, spans the distance between the

side frame members

45 and 46 and is fixedly connected to them at its opposite ends. The interior of the manifold 92 is connected to an appropriate vacuum source (not shown) through a connection 94 as shown in FIGS. 2 and 3. The vacuum belts of conveyor 27, of which three are used in the illustrative embodiment, are each provided with an elongated vacuum chamber 95 which is disposed longitudinaily of the machine and above the lower operative run of the respective belt 29 of conveyor 27. Each vacuum chamber is adjustably supported at its left or rear end upon the manifold 92 through the medium of bracket means, such bracket means also providing support for the rear lower and rear upper belt pulleys of the conveyor.

Thus as particularly shown in FIGS. 6 and 9, affixed to each side of the vacuum box 95 as by being bolted thereto are two parallel similar plate brackets 96, the plate brackets having a rectangular cutout portion in their forward edge, such cutout portion receiving the vacuum manifold 92 therein, as shown in FIG. 9. The two similar plate brackets 96, which are held together in spacedparallel relationship by crossbolts and the axle 97 for the pulley 99, are secured to the manifold 92 by clamping means including an upper clamping shoe 102 (FIGS. 9 and 11). Shoe [02 is thrust downwardly by a screw 10] threaded into a crossmember 103 disposed between and secured to opposed bracket plates 96. Thus, upon the loosening of the shoe 102 by turning screw 10! by thumb wheel 104, the plate brackets 96 and the rear end of the vacuum box or chamber may be adjusted to a desired position laterally of the machine.

Rising from the rear of each of plate brackets 96 and inclined somewhat forwardly is an arm 106, the two such arms at the rear of each vacuum chamber 95 being parallel and at their upper end joumaling a pulley 107 over which the vacuum belt 29 runs. The arms 106 are pivoted upon a cross stud 109 extending through the plate brackets 96, a bolt 110 extending through the lower end of the arms 106 being mounted in arcuate slots 111 in the plate brackets. The arms 106 may thus be swung about the shaft 109 to tighten the belt 29, being held in such position by tightening a nut upon bolt 110.

Adjacent the forward ends of the vacuum chambers 95 is a transverse bar 114 which is affixed to the

frame members

45 and 46 of the machine. The forward end of each of the vacuum chambers 95 is carried by crossbar 114 through the medium of two similar parallel bracket plates 115 which are affixed to the forward end of the vacuum chamber outwardly of the sidewalls thereof. The rear ends of the bracket plates I15 carry a horizontal block 116 which is affixed to such plates, the block overlying the crossbar 114, as shown in FIGS. 6 and 10. The block 116 and thus the forward end of the vacuum chamber are held in position upon the crossbar 114 by a depending pin 117 on bar 116, the pin engaging the rear surface of the bar 114 midway between the plate brackets 115. .Ioumaled in the brackets 115 adjacent the forward edge of the block 116 is an eccentric 119 mounted to swing about a horizontal axis, the eccentric being selectively tightened into engagement with the crossbar 114 to lock the forward end of the vacuum chamber in place upon the crossbar or to loosen it therefrom through the medium ofa handle 120.

A pulley 121 over which the forward end of the belt 29 is entrained is mounted upon and connected by a key 124 to a cross-shafi 122 which is journaled in the

frame members

45 and 46. Each of pulleys 121, which are mounted between the plate brackets 115 of the respective vacuum chamber support, is slidable along the shaft 122 as the vacuum chamber is adjusted laterally of the machine. Shaft 122 is driven by the drive train extending along the outer side of frame member 46, there being a further longitudinal shaft 125 which extends from the gearbox 55 to a gearbox 126, the driven shaft of the latter gearbox being connected to shaft I22 through the medi um of a coupling 127. Coupling 127 is mounted outboard of an L-shaped supporting bracket affixed to the inner face of frame member 46, as shown.

Connection between the vacuum manifold 92 and each of the vacuum chambers 95 is effected by a flexible hose 132 which is connected at one end to a fitting 134 on the manifold 92 and at the other to a fitting 135 on the rear end of the respective vacuum chamber. Means is provided at each of the vacuum chambers 95 for adjusting the effective length of the vacuum chamber, that is, the length of travel of the sheets during which they are grasped by the vacuum belts. Such means takes the form of a downwardly open broad U-shaped member 136 which is made of such width and height as accurately to fit within and slide longitudinally of the vacuum chamber with the lower surfaces of the end walls 137 and 139 just engaging the upper or inner surfaces of the cogs on belt 29. The rear wall 137 of member 136 is provided with holes 138 therethrough whereby the interior of member 136 communicates with the interior of the vacuum chamber 95 proper. The lower face of the upper wall 133 of member 136 is provided with an internally threaded hollow boss 140 which receives a clamping screw 141 which extends through a rear slot 142 in the upper wall 143 of the vacuum chamber 95 proper. A screw 148, threaded into the upper wall 133 of 7 member 136, extends upwardly through a forward slot 144 in the upper wall 143 of the vacuum chamber 95 to maintain member 136 in proper alignment. Upon loosening the screw 141 by its thumb nut 145, the box 136 may be adjusted through ut the length of the slot 142.

As shown in lFIG. 5, the vacuum belt 29 in the illustrative embodiment is provided with two sheet-grasping

stations

146 and 147, such two stations being spaced equally about the length of the belt 29. At each such station there is provided at least one hole 149, such hole being preferably disposed through a thinner or valley portion of the belt between successive ridges or cogs 152 thereon. In the embodiment shown, there are six pairs of holes 149 at each

station

146, 147, the pairs of holes being spaced longitudinally of the belt. When the interior of the manifold 92 is subjected to vacuum, air is drawn into the vacuum chambers through the holes in the then operative one of

zones

146, 147 of the belts 29, which are synchronized by their driving means so that the

zones

146, 147 of the respective belts travel in lateral alignment longitudinally of the belts 29. The

vacuum stations

146, 147 act alternately to pick up successive sheets 26. Air passes into the chambers 95 through the holes 149 in the respective belt 29 when the holes in the respective belt 29 lie between the rear wall 150 of the vacuum chamber 95 and the forward wall 139 of the member 136. Thus the belts 29 of the conveyor 27 grasp a sheet 26 which underlies them throughout the distance from wall 150 to wall 139.

The positions of the

vacuum stations

146, 147 as they travel are critical and must be time, for each sheet cutoff length, so as to pick up the leading end of each sheet 26 as the sheet is delivered to a respective station by the conveyor 21. The conveyor 21 is driven at a speed which is fixed with respect to that of the shear 16. When the sheet cutoff length is changed, the leading end of subsequent sheets are delivered to the vacuum belts 29 so that they initially engage zones of belts 29 which are different from those previously engaged by previous sheets. The above-described clutch 49 is disconnected to permit the vacuum belts 29 to be driven manually while the shear 16 is held from rotation, following which the clutch is engaged so that the vacuum stations may be timed to pick up the leading ends of sheets having the desired new, different length.

As shown most clearly in FIG. 11, the lower edges of the sidewalls of the vacuum chamber 95 are in the form of horizontal flanges 150 which extend horizontally of the chamber and laterally inwardly toward each other for a short distance. The cogged or inner surface of the belt 29 is provided with rabbets 151 which receive the flanges 150' and make substantial seals therewith as the belt travels longitudinally of the chamber. As shown in FIG. 10, the rear and forward end walls 137, 139 of element 136 have their lower edges substantially engaging the upper surfaces of the cogs 152 on the inner surface of the belt 29.

The tapes 32 of the lower, slower speed conveyor 30 at their forward ends run over the above-mentioned turnover drum 34, which is keyed to a cross-shaft 154 extending between and joumaled upon the

side frame members

45 and 46. At their rear ends the tapes 32 run over an elongated small diametered roll 155 which is joumaled by bearings interiorly of the roll 1S5 upon a cross-shaft 156 which extends between and is fixed to the

frame members

45 and 46. The conveyor 30 is provided with an adjustable belt tightener 157, whereby the upper straight runs of the tapes 32 are maintained taut. The relative diameters of the rolls 34, I55 and the location of their axes is such that the upper runs of the tapes 32 inclines forwardly and upwardly toward the lower horizontal operative runs of the vacuum belts 29, tapes 32 lying close to but separated from the forward ends of the belts 29 at the forward end of the conveyor 27 beneath pulleys 121.

As shown perhaps most clearly in FIG. 4, the gearbox 126 has a further driven output shaft to which a first, small gear 159 is affixed. Gear 159 meshes with a second, larger gear 160 which is connected to the input shaft of a further gearbox 161, the output shaft 162 of which has a sprocket 164 affixed thereto. Sprocket 164 drives the shaft 154, upon which the turnover roll 34 is mounted, through the medium of a chain 165 entrained over sprocket 164 and a sprocket 166 on shaft 154.

Spanning the

frame members

45 and 46 and joumaled at its ends in bearings on such members is a horizontal rock shaft I69 upon which there is mounted a plurality of brackets I70 mounting the above-described drop rolls 36. The brackets and the drop rolls carried thereby are shown disposed in alignment with the vacuum belts 29 of conveyor 27, being held in position longitudinally of the rock shaft I69 by clamping means I71 on each bracket I70. A longitudinally extending key 173 on the shaft 169 fits within a groove in the clamping means 171 to maintain the brackets 170 from rotation with respect to the shaft. The described mounting of the brackets I70 on shaft 169 permits the drop rolls 36 to be adjusted laterally of the machine as desired.

The drop rolls 36 are periodically advanced toward the respective tapes 32 of the lower conveyor 30 and are retracted therefrom by means including an arm 172 which is afiixed to the shaft 169 and projects forwardly therefrom at one end of the shaft, as shown in FIGS. 4 and I0, and a cam follower roll I74 which is joumaled upon the outer end of the arm 172. Cam follower I74 rides upon the peripheral surface of a cam 175 which in this instance is made of two generally similar cams which are mounted for adjustment about their common axis so as to adjust the contour of the cam to vary the timing of the movements of the drop rolls 36 with respect to the movement of the other elements of the apparatus. The cam [75 is mounted upon a stub shaft I76 projecting laterally inwardly of the frame member 45, and is driven through the medium of a sprocket I77 affixed to the shaft 154, a sprocket I79 affixed to the shaft 176 and a chain I80 entrained over both such sprockets. The cam follower [74 is maintained in contact with the periphery of cam 175 by a coil tension spring I81, as sanewhat schematically shown in FIG. 10.

As shown in FIG. 10, the cam [75 is of generally circular cylindrical configuration having a main part I83 of its peripheral surface coaxial with the shaft 176, a first curved recess or lower zone 187 and a second recess I88 therein, the two recesses being separated by a lobe 191 having a radially outer zone of circular cylindrical contour. As shown in FIG. 10, the leading end of a sheet 26 is approaching the nip between the turnover drum 34 and the drop rolls 36, the drop rolls then being in lowered position. Just before the leading end of sheet 26 engages the nip, the recess [87 of cam 175 is presented to the cam follower roll I74, permitting the drop rolls 36 to be lifted by the spring I81. The leading end of the sheet 126 thus enters freely between the drum 34 and the drop rolls 36, following which the presentation of the lobe 19] of the cam to the cam follower roll 174 causes the drop rolls to be lowered to the sheet 26 between them and tapes 32. Such forward end of the sheet is thus brought to the speed of the tapes 32 of conveyor 30. Upon further rotation of the cam 175, the cam follower roll 174 drops into the second recess I88 which again permits the drop rolls 36 to rise, so that the sheet 26 will flatten so as to remove any wrinkles which may have formed in it by reason of its reduction in speed to that of the tapes 32. The drop rolls are again lowered by engagement of the main circular cylindrical portion of the cam 175 with cam follower roll 174, the drop rolls remaining in their lowered sheet-gripping position until a sheet 26 has passed by them and the leading end of the next sheet 26 is approaching them.

The machine is provided with further sheet-guiding and edge-aligning means as follows. As shown in FIGS. 2 and 9, bridging the gap between the forward exit end of he lower tapes 24 of the first conveyor 2] and the entering end of the third, slow-speed conveyor 30 is a plurality of flat guide mem bers 182, which are disposed laterally between the

tapes

24, 32 with their upper surfaces spaced at short distance below the lower surfaces of the belts 29 of conveyor 27. Guides 182 are secured respective C-clarnp members 185 which are mounted upon a crossbar 184 extending between

side frame members

45 and 46 of the machine. A further crossbar 189 extends between

side frame members

45 and 46. Upon such crossbar through the medium of C-clamps 190 there are mounted two opposed edge guides 186 for the sheets 26 travelling therebetween. The above-mentioned curved wire guides 35 are mounted upon a third crossbar 193 through the medium of C-clarnp members 197 which are secured to the guides 35. The edge guides 186 and the guide member 35 may thus be adjusted laterally of the machine as required.

The sheets in shingled form travel over the drum 34, being maintained in substantial contact therewith by the curved guide members 35. Forwardly and beneath the drum 34 there is disposed a downwardly and rearwardly inclined further conveyor 39, such further conveyor having a plurality of laterally spaced tapes I94 entrained over a forward upper horizontal roll I92 and a lower horizontal roll 195. The tapes I94 are maintained with their upper runs taut by an adjustable belt or tape tightener as shown. The lower rear roll serves also as the support and driving means for the forward ends of a plurality of tapes 4] of the lower, stacking conveyor 40. Roll 195 is driven by a chain (not shown) which runs over a sprocket affixed to the forward shaft 122 of the vacuum belt conveyor. The tapes 4! of conveyor 40 extend rearwardly with the upper run of such tapes disposed horizontally so as to carry the now turned over stream of shingled sheets to the stacking station. At the rear end of such station the sheets encounter an adjustable end stop 42 which forms the sheets into a stack which is continually replenished by sheets which are fed to the bottom of the stack by conveyor tapes 4]. As above disclosed, such manner of stacking of the sheets leaves them free for successive feeding from the top of the stack to sheet-processing apparatus such as a printing press.

The manner of cooperation of a sheet 26 with

conveyors

21, 27, and 30 is particularly shown in FIGS. 9 and 10. As shown in FIG. 9, a sheet 26 has been forwarded to conveyor 27 by the upper and lower tapes of conveyor 21, the leading end of the sheet having just been grasped by the vacuum-powered grasping station 46 of the belts (one shown) 29 of the conveyor 27. The leading end 199 of sheet 26 extends slightly forward of .the'forwardmost holes [49 through belt 27; portions of the sheet between belts 29 slide along the upper surfaces of guides 182. The sheet travels forwardly, with its leading end pulled by belts 29 at the same speed as the body and trailing end thereof are fed by conveyor 21, until the trailing end of the sheet has left tapes 24 of the first conveyor, afier which the sheet is fed forwardly only by conveyor 27. The body and trailing end of the sheet, after having passed the forward ends of the fixed guides [82, sag downwardly upon and are dragged along the tapes 32 of conveyor 30, which travels at a speed which is markedly less than that of conveyor 27.

In FIG. 10, for the purpose of simplicity of illustration, there is shown a single sheet 26 which is being fed forwardly by the conveyor 27, the intermediate and trailing portions of the sheet being shown as directly engaging the tapes 32 of conveyor 30. it will be understood that in the actual operation of the apparatus, except for the first sheet which is fed through it, the intermediate portion and trailing end of a subsequently fed sheet will rest upon one or more previously fed sheets supported on tapes 32. in FIG. 10 a sheet 26 is shown as having travelled so that its body and trailing end lie upon and are being pulled along the slower travelling tapes 32, its forward end having been released from all but the rearmost pair of holes 149 in belt 29, and such rearmost pair of holes 149 being about to be cut off from the vacuum source by their passage forwardly past the forward wall 139 of the device 136 in the vacuum chamber 95.

As the sheet 26 reaches the forward end of the effective length of the vacuum belts 29, the portion of the sheet 26, which is shown as being upwardly bulged at 200, will be released by the belts 29 so that the sheet as a whole falls upon the stream of sheets upon the tapes 32 of the conveyor 30. The speed of conveyor 30 may be, for example, a small fraction of the speed of the

conveyors

21 and 27. As a result, a subscquently fed sheet, as its forward end is released by the conveyor 27, will be deposited upon the previously fed sheet with the leading end of the later fed sheet overlying the trailing end of the previously fed sheet.

The drop rolls 36 cooperate with turnover drum 34 and the tapes 32 entrained thereover positively to feed the stream of sheets 26 in synchronism with the turnover drum, to decrease the speed of the last-fed sheet to that of the conveyor 30, and to relieve the last-fed sheet of wrinkles. The drop rolls 36 are raised just before the leading end of the last-fed'sheet 26 reaches them. The drop rolls are then lowered to engage the sheet just rearwardly of its forward end so as to slow the sheet, which is still travelling at a relatively high velocity, to the slower speed of the tapes 32 at the turnover drum 34. Because of such rapid decrease in velocity of the sheet, parts of the sheet rearwardly of the nip between the drop rolls and the tapes 32 at the drum are apt to wrinkle. The drop rolls are now lifted to free the sheet and to allow whatever wrinkles that have formed in it to smooth out. The drop rolls again are lowered so that the forward end of conveyor 30 drives the stream of shingled sheets 38 around the turnover drum and down a further, inclined conveyor 39 to a stacking station 40. The drop rolls remain in lowered position until the leading end of the next sheet approaches them.

Most of the advantages of the apparatus of the invention over prior art apparatus of the same general type will be apparent from the above. The present apparatus may be readily adjusted to form and handle sheets having lengths which may be varied over a very substantial range. As above explained the length of sheet produced is changed by changing the speed of feed rolls 12 by adjustment of the variable-speed gearing device is. Thereupon, the nip forming means 25 is suitably adjusted longitudinally of conveyor 21, the clutch 49 is disengaged to permit the

conveyors

21, 27, and 30 to be driven by hand to bring one of the vacuum-powered sheet-gripping stations I46, 147 into the correct phase relationship relative to the cutter of the shearing means I6, following which the clutch 49 is engaged.

The apparatus of the invention may be adjusted to handle sheets of various widths by suitably adjusting the vacuum chambers 95 with their conveyor belts 29 laterally of the apparatus, and adjusting the

guides

35, 182, and 186 accordingly. If desired, the assemblies of conveyor 27 may be adjusted so as to lie at a small angle relative to the ath of travel of the sheets, for example, so that the two laterally outer conveyor assemblies diverge slightly in a forward direction. This causes the sheets to be tensioned crosswise as they travel, thereby to hold them from lateral wrinkling.

Although only one embodiment of the invention has been illustrated in the accompanying drawings and described in the foregoing specification, it is to be especially understood that various changes, such as in the relative dimensions of the parts, materials used, and the like, as well as the suggested manner of use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention, as will now be apparent to those skilled in the art.

lclaim:

I. In a sheet-handling apparatus, sheet-delivering means, a first sheet-gripping conveyor driven to successively feed said sheets forwardly at a faster speed than the speed at which the same are delivered by said means, said first conveyor including means spaced downstream from said first-named means for forming a nip in the first conveyor at which the sheets are initially gripped by the first conveyor, a second conveyor downstream of said first conveyor, disposed above the path of travel of the sheets carried by the first conveyor, and driven at the same speed and direction as such first conveyor for receiving sheets from said first conveyor, said second conveyor having periodically operated means thereon for grasping and pulling forward the leading end of each sheet while pennitting the trailing end of the sheet to sag downwardly appreciably, and a third conveyor partially overlapping the second conveyor and disposed substantially below the level of the sheetgrasping means for receiving sheets released by the sheetgrasping means at the forward end of the second conveyor, said third conveyor being driven to forward sheets at a speed which is appreciably lower than the sheet-forwarding speed of the first and second conveyors, whereby there is formed on the third conveyor a stream of overlapped sheets in shingled relationship with the leading end of each sheet lying above the trailing end of the previously fed sheet.

1. Sheet-handling apparatus according to claim 1, wherein the first conveyor comprises opposed synchronously driven belts with opposed sheet-engaging runs, the ends of the belts rearwardly of said runs being appreciably spaced from each other, and the nip-forming means comprises means for pressing the opposed runs of the belts toward each other at a location forwardly of the rear ends of the belts.

3. Sheethandling apparatus according to claim 2, wherein the nip-forming means comprises opposed rolls disposed with their axes transverse to the lengths of the opposed sheet'engaging runs of the belts, said rolls engaging the surfaces of the respective belts which are opposite the sheet-engaging sur' faces thereof.

4. Sheet-handling apparatus according to claim I, wherein the second conveyor comprises a belt having said sheet-grasping means thereon at one zone thereof, and comprising drive means for the belt which positively maintains it in synchronism and in phase with the sheet-delivering and the first conveyor.

5. Sheet-handling apparatus according to claim 4, wherein the belt of the second conveyor has spaced cogs thereon, and comprising sprockets which mate with said cogs over which the belt is entrained, and wherein the means to drive said belt comprises means for driving at least one of said sprockets.

6. Sheet-handling apparatus according to claim 4, comprising means for selectively disconnecting the drive means for the belt of the second conveyor, whereby to permit the adjustment of the position of the sheet-grasping means thereon relative to the sheet-delivering means.

7. Sheet-handling apparatus according to claim 1, wherein the second conveyor comprises an elongated vacuum chamber extending along and above the path of travel of the sheets, said vacuum chamber having a hollow body with spaced side and end walls forming an enclosure with an open lower end, and a belt having a longitudinally extending run thereof bridging and substantially closing the lower end of the vacuum chamber, the belt being driven so that said run of the belt travels downstream, wherein said sheet-grasping means comprises at least one opening through the belt providing communication between the interior of the vacuum chamber and the underside of said run of the belt, and comprising means to subject the interior of the vacuum chamber to reduced pressure.

8. Sheet-handling apparatus according to claim 7, comprising drive means for the belt of the second conveyor which positively maintains said belt in synchronism and in phase with the sheet-delivering and the first conveyor.

9. Sheet-handling apparatus according to claim 8, wherein the belt has spaced cogs thereon and said drive means comprises sprockets which mate with said cogs over which the belt is entrained.

l0. Sheet-handling apparatus according to claim 9, wherein the cogs on the belt are on the surface thereof which is opposite its sheet engaging surface.

ll. Sheet-handling apparatus according to claim 7, comprising means for adjusting the length of the path through which the sheet-grasping means is operative to retain the forward end of a sheet being fed thereby.

12. Sheet-handling apparatus according to claim ll, wherein the means for adjusting the length of the path through which the sheet-grasping means is operative comprises means forming a transverse partition closing the forward end of the vacuum chamber, and means to adjust said partition longitudinally of the main body of the vacuum chamber.

13. Sheet-handling apparatus according to claim 7, comprising a plurality of similar generally parallel vacuum chambers each having a belt cooperating therewith, and comprising means mounting the vacuum chambers and belts for adjustment laterally toward and away from each other to accommodate the apparatus to the handling of sheets of different widths.

14. Sheet-handling means according to claim 13, wherein the means for mounting the vacuum chambers is so constructed and arranged as to permit the laterally outer vacuum chambers and belts to be adjusted so that they diverge in a downstream direction, whereby the forward ends of sheets fed by the belts may be laterally tensioned by the laterally outer belts.

l5. Sheet-handling apparatus according to claim 1 wherein the third conveyor comprises means at its forward end for supporting the overlapped sheets while they continue to travel,

and at least one drop roll disposed above the supporting means selectively to form a nip therewith, and means periodically to raise the drop roll from engagement withthe overlapped sheets as they travel therepast and to lower the drop roll into engagement with such sheets.

16. Sheet-handling apparatus according to claim I5, wherein the means to raise and lower the drop roll comprises means to lower the drop roll into momentary engagement with the leading edge of each sheet as it travels therepast, to raise the drop roll from the sheet immediately thereafter, shortly thereafter again to lower the drop roll into momentary engagement with the sheet, and thereafter to raise the drop roll until the leading edge of the next successive sheet is presented thereunder, whereby to eliminate wrinkles from the sheets.

17. Sheet-handling apparatus according to claim I6, wherein the means to raise and lower the drop roll comprises cam means driven in synchronism with the third conveyor, cam follower means connected to the means mounting the drop roll, the cam and cam follower means cooperating to raise the drop roll, and spring means retaining the cam follower means in engagement with the cam and periodically advancing the drop roll toward said sheet-supporting means.

18. Apparatus for handling sheets, comprising a first, higher speed conveyor, means on the first conveyor for grasping and holding elevated the leading end of a sheet and pulling the sheet forward by its leading end, a second, lower speed conveyor disposed below the first conveyor, the second conveyor being so spaced vertically from the first conveyor that the trailing end of the sheet is supported by the second conveyor, means for releasing the sheet from the first conveyor and depositing the sheet upon the second conveyor after at least the leading end and a substantial part of the intermediate portion of the sheet overlie the second conveyor, and means for slowing down the released sheet to the speed of the second conveyor, said last-named means comprising at least one drop roll cooperating with the second conveyor and drop roll controlling means including means for periodically first raising the drop roll to receive the leading end of the sheet between it and the second conveyor and means for thereafter lowering the drop roll into engagement with the sheet closely adjacent its leading end.

19. Apparatus according to claim 18, wherein the drop roll controlling means comprises means for again raising the drop roll after its initial engagement with the sheet and thereafter again lowering the roll and maintaining it in engagement with the intermediate portion of the sheet for a substantial time.

20. Apparatus for handling sheets, comprising a first, higher speed conveyor for forwarding a plurality of sheets in flat condition in spaced relationship, a second conveyor travelling at substantially the speed of the first conveyor receiving sheets in sequence from the first conveyor, means on the second conveyor for grasping and holding elevated the leading ends of the sheets as they are presented to the second conveyor and pulling successive sheets forward by their leading ends, a third, lower speed conveyor disposed below the second conveyor, the third conveyor being so spaced vertically from the second conveyor that the trailing end of each grasped sheet is supported by the third conveyor, means for releasing the leading end of each sheet from the second conveyor and depositing it upon the third conveyor after a substantial part of the sheet overlies the third conveyor, so as to form a shin led stream of sheets on the thlrd conveyor wherein the lea mg endof each sheet as released overlies the trailing end of each previously released sheet, means including a drum at the forward end of the third conveyor for turning over the shingled stream of sheets, and means for slowing down each sheet last deposited on said shingled stream to the speed of the shingled stream of sheets, said last-named means comprising at least one drop roll overlying the turnover drum and drop roll controlling means including means for periodically first raising the drop roll to receive the leading end of the last-deposited sheet therebeneath and means for thereafter lowering the drop roll into engagement with the last-deposited sheet closely adjacent its leading end.

21. Apparatus according to claim 20, wherein the drop roll controlling means comprises means for again raising the drop roll after its initial engagement with the last-deposited sheet and thereafter again lowering the roll and maintaining it in engagement with the last-deposited sheet for a substantial time whereby the shingled stream of sheets in its travel is pressed between the turnover drum and the drop roll.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. Dated July 27 1. 71

Imyvmn" J De Young Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

lolfl wm g), lino sear" ehould row? shear sutrrr 1710 comminricr't; :1.

lino Column 3, line 2H,

mum 11 10 I'flm: him-2d Column 9, line 67, after voouroj nr or'iz to Column 12, line 22, after "sheet- H-[ZllVJIIU'IPI insert moans line 51, after "qheotlnliv rrin t" insert means Signed and sealed this 25th day of January 1972.

(SEAL) Attest:

EDWARD M.FLE'TCHER,JR. ROBERT GUTTSCHALK Attasting Officer Commissioner of Patents U 5 GOVERNMENT PRINYING OFFICE: IBIQ O-Ji-5Jl

Claims

1. In a sheet-handling apparatus, sheet-delivering means, a first sheet-gripping conveyor driven to successively feed said sheets forwardly at a faster speed than the speed at which the same are delivered by said means, said first conveyor including means spaced downstream from said first-named means for forming a nip in the first conveyor at which the sheets are initially gripped by the first conveyor, a second conveyor downstream of said first conveyor, disposed above the path of travel of the sheets carried by the first conveyor, and driven at the same speed and direction as such first conveyor for receiving sheets from said first conveyor, said second conveyor having periodically operated means thereon for grasping and pulling forward the leading end of each sheet while permitting the trailing end of the sheet to sag downwardly appreciably, and a third conveyor partially overlapping the second conveyor and disposed substantially below the level of the sheet-grasping means for receiving sheets released by the sheet-grasping means at the forward end of the sEcond conveyor, said third conveyor being driven to forward sheets at a speed which is appreciably lower than the sheet-forwarding speed of the first and second conveyors, whereby there is formed on the third conveyor a stream of overlapped sheets in shingled relationship with the leading end of each sheet lying above the trailing end of the previously fed sheet.

2. Sheet-handling apparatus according to claim 1, wherein the first conveyor comprises opposed synchronously driven belts with opposed sheet-engaging runs, the ends of the belts rearwardly of said runs being appreciably spaced from each other, and the nip-forming means comprises means for pressing the opposed runs of the belts toward each other at a location forwardly of the rear ends of the belts.

3. Sheet-handling apparatus according to claim 2, wherein the nip-forming means comprises opposed rolls disposed with their axes transverse to the lengths of the opposed sheet-engaging runs of the belts, said rolls engaging the surfaces of the respective belts which are opposite the sheet-engaging surfaces thereof.

4. Sheet-handling apparatus according to claim 1, wherein the second conveyor comprises a belt having said sheet-grasping means thereon at one zone thereof, and comprising drive means for the belt which positively maintains it in synchronism and in phase with the sheet-delivering and the first conveyor.

10. Sheet-handling apparatus according to claim 9, wherein the cogs on the belt are on the surface thereof which is opposite its sheet engaging surface.

11. Sheet-handling apparatus according to claim 7, comprising means for adjusting the length of the path through which the sheet-grasping means is operative to retain the forward end of a sheet being fed thereby.

12. Sheet-handling apparatus according to claim 11, wherein the means for adjusting the length of the path through which the sheet-grasping means is operative comprises means forming a transverse partition closing the forward end of the vacuum chamber, and means to adjust said partition longitudinally of the main body of the vacuum chamber.

15. Sheet-handling apparatus according to claim 1, wherein the third conveyor comprises means at its forward end for supporting the overlapped sheets while they continue to travel, and at least one drop roll disposed above the supporting means selectively to form a nip therewith, and means periodically to raise the drop roll from engagement with the overlapped sheets as they travel therepast and to lower the drop roll into engagement with such sheets.

16. Sheet-handling apparatus according to claim 15, wherein the means to raise and lower the drop roll comprises means to lower the drop roll into momentary engagement with the leading edge of each sheet as it travels therepast, to raise the drop roll from the sheet immediately thereafter, shortly thereafter again to lower the drop roll into momentary engagement with the sheet, and thereafter to raise the drop roll until the leading edge of the next successive sheet is presented thereunder, whereby to eliminate wrinkles from the sheets.

17. Sheet-handling apparatus according to claim 16, wherein the means to raise and lower the drop roll comprises cam means driven in synchronism with the third conveyor, cam follower means connected to the means mounting the drop roll, the cam and cam follower means cooperating to raise the drop roll, and spring means retaining the cam follower means in engagement with the cam and periodically advancing the drop roll toward said sheet-supporting means.

20. Apparatus for handling sheets, comprising a first, higher speed conveyor for forwarding a plurality of sheets in flat condition in spaced relationship, a second conveyor travelling at substantially the speed of the first conveyor receiving sheets in sequence from the first conveyor, means on the second conveyor for grasping and holding elevated the leading ends of the sheets as they are presented to the second conveyor and pulling successive sheets forward by their leading ends, a third, lower speed conveyor disposed below the second conveyor, the third conveyor being so spaced vertically from the second conveyor that the trailing end of each grasped sheet is supported by the third conveyor, means for releasing the leading end of each sheet from the second conveyor and depositing it upon the third conveyor after a substantial part of the sheet overlies the third conveyor, so as to form a shingled stream of sheets on the third conveyor wherein the leading end of each sheet as released overlies the trailing end of each previously released sheet, means including a drum at the forward end of the third conveyor for turning over the shingled stream of sheets, and means for slowing down each sheet last deposited on said shingled stream to the speed of the shingled stream of sheets, said last-named means comprising at least one drop roll overlying the turnover drum and drop roll controlling means including means for periodically first raising the drop roll to receive the leading end of the last-deposited sheet therebeneath and means for thereafter lowering the drop roll into engagement with the last-deposited sheet closely adjacent its leading end.