US2684241A - Sheet stacking device - Google Patents

Description

H. E. PEYREBRUNE ET AL SHEET STACKING DEVICE July 20, 1954 5 Sheets-Sheet 1 Filed March 22, 1950 INVENTORS Henri E. Peyrebrune By Bruno 5. Pasqu/nel/i July 20, 1954 Filed March 22. 1950 H. E. PEYREBRUNE ETAL 2,

SHEET STACKING DEVICE 5 Sheets-Sheet 2,

INVENTORS Henr/ 1f Peyrebrune BY Bruno 5. Pasqurhel/i wwzgmwz y 1954 H. E. PEYREBRUNE ET AL 2,684,241

SHEET S-TACKING DEVICE 5 Sheets-Sheet 5 Filed March 22, 1950 B u 6 on f vm mm hm N PM m u 9 MN F e .1 mww mi FEW. WW 18p 0 Z M5 V. B

y 1954 H. E. PEYREBRUNE ET AL 2,634,241

SHEET STACKING DEVICE 5 Sheets-Sheet 4 Filed March 22, 1950 8 m 0 u e mh A 5 W Vw me wwxd/gwa July 1954 H. E. PEYREBRUNE ETAL 2,684,241

SHEET STACKING DEVICE Filed March 22, 1950 5 Sheets-Sheet 5 IN V EN TORS Henri 1:. Peyrebrune BY Bruno 5. Fbsqu/ne/h' Patented July 20, 1954 UNITED STATES PATENT OFFICE SHEET STACKING DEVICE Application March 22, 1950, Serial No. 151,066

8 Claims.

This invention relates to improvements in mechanism whereby sheets of cardboard, after having been processed in a cutting and creasing press to produce blanks for folding boxes or the like articles, are delivered one by one and stacked in superposed, aligned relation onto a supporting table.

The invention more specifically pertains to novel means whereby a smooth and evenly stacked pile of cut and creased blanks will be assured and whereby the stacked sheets will be held together against any accidental displacement with relation to each other.

In the process of manufacturing folding boxes and similar articles made of carton stock, the cut and creased sheets must be stripped of their waste portions, or scrap, retaining those parts only which constitute the blanks of the articles to be produced.

This stripping operation must be performed at a station remote from the cutting and creasing machine and preferably with the aid of an airhammer or such like device. In transferring the stacked sheets to such station, utmost care must be exercised by the operator so that the alignment of the stacked carton blanks will not be disturbed, otherwise the task of stripping the waste portion from the blanks will become very difficult and result in considerable loss of time and material.

The basic principle and advantage which our invention offers, is the provision of means whereby each blank, as it is being deposited, will become locked in proper alignment with the previously deposited blanks in a manner that the pile of blanks will not become disarranged during its removal from the machine.

With this object in View, we propose to provide one or more out out portions or flaps in each blank, preferably atthe same time when the blanks are being cut and creased, which flaps are of such design that they can be depressed by means of suitable mechanism so that each flap, as a blank is being delivered, will align itself with the opening formed by the depressed corresponding flaps of previously deposited blanks. In many instances a suitable portion of the box blank may be used to serve as the interlocking flap, thereby obviating the necessity of providing a die to cut a special flap for this purpose.

Another object and important advantage of our invention resides in the provision of means which will function to positively control the carton blanks during their travel from the cutting and creasing members of the machine to the point 2 where the blanks are being deposited onto the supporting table, i. e., delivery pile.

The mechanism involved preferably includes an endless chain conveyor provided with grippers by means of which the cut and creased carton blanks are engaged and carried under positive control to said table.

To cooperate with this conveyor, and in order to still further assure a positive control of the blanks while being delivered, we propose to arrange a reciproating carriage which has for its purpose to serve as a support for an entire sheet while it is being conveyed towards the delivery pile, and for its trailing portion during that period when the sheet is being deposited onto the pile.

A further object of the invention resides in the provision of reciprocating stacking grippers which are in cooperative association with the grippers of said chain delivery to engage the leading edge of each blank at a predetermined point in its travel and deposit it smoothly onto the previously delivered blanks.

Preferably, the novel means whereby said cut out portions or flaps are depressed in order to lock the blanks together in proper aligned relation, are associated with said reciprocating grippers in a manner that the out out flaps are depressed as soon as a blank is deposited and While still in the bite of said grippers. This assures accurate stacking of the delivered carton blanks.

Other objects and advantages of our invention will become apparent from the following description and appended claims when read in conjunction with the accompanying drawings which depict a preferred embodiment of the novel mechanism involved.

In these drawings,

Figure 1 illustrates in side elevation the general arrangement of a sheet delivery mechanism as applied to a cylinder flatbed press;

Figure 2 depicts a side elevational view, partly in section, and featuring the stacking grippers and their associated mechanism in their position wherein the carton blanks are to be taken over from the chain delivery mechanism;

Figure 3 is a view similar to Figure 2, but showing the stacking grippers and their associated mechanism in their position assumed when de positing a sheet onto the pile of stacked sheets;

Figure 4 is an enlarged sectional view illustrating how the flaps are being depressed to lock the sheets together;

Figure 5 is a plan view of that part shown in Figure l;

Figure 6 is a view in elevation showing the mechanism for actuating the various elements of the stacking device;

Figure '7 is a View in elevation illustrating the delivery end of the carton stacking device, and

Figure 8 is a view showing means for locking the stacking mechanism in its inoperative posi tion.

Referring now to these drawings, Figure 1 discloses a preferred embodiment of the sheet stacking device in associated relation with a conventional cutting and creasing press having side frames is journalling a sheet carrying cylinder ii. Blanks of card board, or similar material, are fed to grippers ii on said cylinder over the feed table 53, either by hand or by automatic feeding means, and are then out and creased in the conventional manner by bringing the blanks into contact with a cutting and creasing carried on a reciprocating bed M.

Transversely disposed in parallel relation to the cylinder ii is the shaft 55, which extends the full width of the press with its ends suitably journalled for oscillation in side frames or brackets, not shown, provided therefor. A series of arms it, each carrying at its free end a rider roller 57, are fixed securely to said shaft, By means of any conventional mechan oscillating movement is imparted to shaft is to thereby swing the arms IE and therewith the rollers ll intermittently up and down for the purpose of controlling each sheet while on and during its removal from the cylinder El.

Operating in conjunction with the rollers H and functioning to strip the out and creased sheets from the cylinder H are the stripping fingers 58, a series of which are fixed to a second transversely disposed shaft l9. This shaft is also journalled for oscillation to thereby move the stripping fingers from an operative position in close proximity to the cylinder, to an inoperative position spaced therefrom and this inovement timed with direct relation to the movement of the rollers il as is well known in the art.

Each succeeding sheet, while on its way to the delivery pile, is supported on horizontally disposed bars 28 to which the sheets are transferred by the coaction of the rollers l! and stripping fingers '18. A. series of said bars are located in spaced relation adjacent the lineal path of t e delivery gripper elements and function to guide the leading or gripper edge of the sheet into the bite of the delivery gripper pads 2i and the grip per fingers 22 and into contact with a plurality of sheet stops or guides 23. The gripper pads 25 and fingers 22 are mounted in series on their respective shafts E i and 25, said shafts being carried in the customary manner by endless chains which are indicated by the broken line in Figure 1.

Opening and closing action of the fingers 22 is effected by means of the lever 26 fixed securely to one end of shaft 25 and carrying the roller 2i which engages an adjustable cam 28. B means of this cam, the closing of the gripper fingers 22 can be timed, depending on the size of the sheets that are to be handled on the machine. For maximum size sheets, the cam 28 is positioned as indicated by the solid lines in Figure 1. To facilitate the handling of smaller size sheets the cam would be moved a relative amount toward the extreme dotted line position,

the extent of movement being determined by the size of the sheet being processed.

Due to the relatively heavy weight of the material used for making folding carton like articles, and because of the fact that the carton blanks in a cut and creased sheet are held together merely by small nicks spaced along the out lines, the trailing portion of the sheets cannot be floated to the delivery pile in the same manner as is common practice in delive g sheets from a printing press which sheets are of coinparative light weight stock. Unless some means is provided to support each sheet as it is conveyed to the delivery pile, the trailing portion would have a tendency to drop onto the press mechanism and would obviously be dragged over the preceding sheets already on the pile. Consequently, the aligned position of the previously delivered sheets would be disturbed regardless of the accuracy with which they were ori inally deposited onto the pile. Furthermore, any undue bending or dragging of a cut and creased sheet will break such nicks, resulting in he separation of the cut portions thereby making it virtually impossible to deposit and align the sheets in a satisfactory manner.

To obviate these difficulties, a reciproca' carriage is operatively associated with the ob conveyor so as to provide a support for the t1 ing portion of each sheet as it is being convey to the pile support and until it is be deposited in aligned relation to the previously delivered sheets on the pile.

This mechanism comprises a sheet support or platform 29 which is mounted for reciprocation in tracks 3E) by means of the rollers 3i. It will be understood that a similar track and are provided at each side of the delivery mesh-- anism. A shaft 32 is arranged to be rotated in a clockwise direction as the support returns its sheet taking position, thereby gently t l the sheet off the platform 29 and support trailing portion of it while the sheet is livered and stacked. nism whereby reciprocating motion is to the carriage and whereby the roller l ated, is not shown. Such mechanisms are. known in the art and do not f0 in any essei 3 part of the present invention.

register on the accumulating pile by 1..

the stacking mechanism which is illustrated in Figures 2 and 3. The

to a position immediately above the v in which position the leading or gripper edge of the sheets is projected between the lower j t and upper jaw 35 of the sheet stacking gri 1 The lower jaw 3c is pivotally supported connected to lever 38 which has a bifurcated end portion freely mounted on a transversely shaft 39. A coacting lever to is rigidly secureil to the shaft 39 between the forked ends 0;

38 and movement of the shaft 3s and the the lever it is transmitted to lever th ough the rod 4| and spring 42. The rod pivoted to lever 38 with its free end slid serted through the pivoted boss 33 prcvxiet c the lever 46. The spring d2 exerts sufiici pressure between the bracket 43 the adjus able nuts 45 to maintain adjustable stops and ii on the levers lit and 38 respectively in intimate contact relation. Therefore, it is obvious that any movement of shaft 39 will be transmitted through the lever 40 to lever 38 and thereby to the rod 31 and gripper jaws 34 and 35.

The rearwardly extending arm of jaw 34 is pivoted on a pin 63 carried by the upper end of the arcuate lever 49 which, at its lower portion, is securely mounted on the shaft 56 by means of the bolt 5; and key 52. The upper jaw 35 is also pivoted on the pin 36 and has attached to its depending arm the connecting rod 53 which is in turn connected to one arm of the bell crank lever 54 pivoted on a pin 55 which is mounted on the lever 49.

The lever 54 is constantly urged in the clockwise direction by means of the spring 56 which embraces the rod El the lower end of which is pivoted to the lever 54, whereas the rod itself is free to slide within a bore provided in a pin 53 carried in lever 49. The compression spring 5% exerts pressure between pin 58 and the nut 59 thereby urgin the rod 5'! upwardly and conseouently the bell crank as in a clockwise direction.

At its free end the lever 5 3 carries a roller 6?! which rides over the cam iii having high parts 62 and 53 and low part it. This cam is composed of two sections, each one being adjustably fas tened to the yoke 65 by means of bolts 66, the yoke in turn is freely mounted on the shaft 59 to rock about its axis. Motion independent of shaft 59 is imparted to the yoke 55 through the connecting rod 6'! the free end of which is attached to the bracket 68 fixed on the shaft 69. A lever or stop l'fi is also fixed to the bracket 63 the purpose of which will be explained later.

The stacking finger holder H is pivotally mounted on the pin 35 and is formed with a depending portion 12 at its free end. An arcuate slot is is provided in said depending portion into which slot extends the pin 68 carried by the lever it. The weight of the portion l2 tends to maintain the top of slot it in contact with the pin 48 during that period when the stacking finger it is inoperative, thereby causing the holder to remain in a horizontal position as shown in Figure If desired, a spring could be applied in order to urge holder H in a clockwise direction so as to maintain its horizontal position.

In the preferred embodiment, and as shown in Figure '7, two stacking devices are provided.

Each holder ii is equipped with a stacking finger M which may be adjusted longitudinally of the holder and which functions to depress a predetermined portion of a folding box blank such as a tab 15, see Figures 3, 4 and 5, into interlockrelation. with previously delivered sheets on the pile.

As each subsequent sheet is grasped by the stacking device grippers 34 and 35, continued movement of shafts 39 and 50 causes the mechanism to assume a retracted position as illustrated in Figure 3, where the gripper fingers are shown depositing a sheet in precise, superposed relation on the pile and the stacking finger M is depressing the precut tab '55 into interlocking relation with the preceding sheets already on the pile. Figures 4 and 5 illustrate more clearly and to an enlarged scale the action which takes place as each. succeeding sheet is deposited onto the pile. It will be understood of course that in these enlarged views the thickness of the sheets is some what exaggerated and it appears as though the tab, when depressed, only interlocks with a small number of the preceding sheets. However, in actual practice the sheets are only a few thousandths of an inch thick, consequently each tab interlocks with a considerable number of previously deposited sheets adding to the rigidity of the built-up pile.

Movement of the finger i l to depress the interlocking tabs is efifected by means of the lever iii which intercepts the depending portion 12 of holder H as the stacking device moves to its retracted position, causing the holder ii to rock about the pin 36 thereby imparting an anti-clock- Wise movement to finger M as it depresses the associated tab, see Figure 3.

Rocking motion of the shafts 3t, 5t and 89, whereby the stacking device is actuated to deposit each succeeding sheet onto the pile, is accon1 plished in timed relation to the chain delivery grippers 2E, 22 by means of the cam and lever arrangement shown in Figure 6. The main drive shaft El carries a worm 7B which meshes with an associated Worm gear la, said gear being fixed to a driven shaft 80. A series of cams Si, 82 and 83 are also fixed to shaft and rotate therewith in a counter-clockwise direction.

By virtue of the contour of cams iii, 82 and 83 a relative rocking motion is imparted to the levers 8t, 85 and 85 through their rollers 37, 88 and 89 respectively. Lever M is pivoted on the stud 9S, fixed in the frame 9!, and carries at its free end a connecting rod 92 which passes through a boss 83 provided on the frame s1 and the lower end of which is connected to a lever or. which is rigidly keyed to the shaft "59. A spring 95 which embraces the rod 92 and the upper end of which bears against said boss urges lever 84 in a clockwise direction thereby maintaining roller 8! in constant contact with its associated earn 8 i.

The lever 85 is actuated in a similar manner, being pivoted on stud 96 and having attached to its free end the connecting rod 91. The lower end of this rod is in turn connected to lever 52 which is rigidly secured to shaft 5i). Intimate contact of roller 88 with its respective cans 82 is maintained through the spring 98 mounted on rod Hit which in turn is connected at its upper end to lever 85 while its free end is slidably guided through the boss ill! on the frame 9!. The spring 9.) exerts pressure against boss 19! and lever 85 thereby constantly urging said lever in an anti-clockwise direction.

By a similar arrangement cam 83 transmits reciprocal motion to the shaft 39. Lever 8G is pivoted on stud H13 having a connecting rod Iiil attached thereto, which in turn is secured to lever 35, said lever being fixed on shaft 33. A rod Hi5, which passes through a boss m2 also attached to lever 86 and the spring ill! mounted thereon urges this lever in an anti-clockwise di rection thereby maintaining the contact relation of roller 89 with cam 83.

It will be apparent therefore that any motion imparted to the levers 84, 85 and 86 by virtue of the rotating cams 8!, S2 and 83 will be transmitted directly to the actuating shafts 69, 5e and 39 respectively.

As indicated herein, the preferred embodiment of this invention comprises a plurality of stacking gripper units in order to positively control the delivery of the blanks to be stacked and to thereby insure accurate register of the stacked blanks or sheets. Figure 7 illustrates the manner in which said units are disposed transversely of the pile and since they are adjustable longitu dinally on the actuating shafts 39, 59 and t9, the units can be positioned so that any suitable portion of a precut folding box blank could be conveniently used to provide an interlocking tab.

In other words, in such event it would not be necessary to set up special dies to cut out tabs in predetermined positions in order to have them coincide with the stacking fingers.

To further insure positive register of the do livered sheets, accurate and positive positioning of the pile support itself is also required. Because the pile support H rests on beams H! which in turn are suspended by chains in a conentional manner, it is not unusual in such ar rangement for the pile support to swing or sway to a limited extent due to vibrations and move ment of the various mechanisms involved. To prevent any other than vertical movement of the support, rods H2, see Figures 1 and 7, are removably secured to the beams Hi and carry flanged rollers H3 at one end which are fitted between L-shaped tracks lid mounted on each side of the delivery frame. By this means the support 5 ii! is free to he raised or lowered while the flanged rollers will prevent any lateral sway, i. horizontal movement thereof.

Looking means are also provided whereby the stacking mechanism may be locked in an inoperative, retracted position, see Figure 8. The lever H5 pivotally mounted on stud ill is held in an inoperative position, as indicated by dotted lines by the leaf stpring H6 fixed to lever H6. This spring rests on the projecting knob H9. Rigidly fixed to shaft as is the collar 12s formed with a notch 22!, while on shaft 5i; is fixed a similar collar I22 having a notch i2? To look the mechanism, the lever lit is moved from its inoperative, dotted line position to its operative, full line position in which the lip E24 engages notch 12! in the collar E23 and the edge E25 engages notch 23 in collar 522, thereby holding shafts 39 and 5E) in their retracted position against the pressure of the springs 99 and it? respectively, see Figure 6.

In operating our novel stacking device, having reference to Figure 1, the blank sheets of paper or card board are fed over the feed board 23 to the sheet carrying impression cylinder i l, which together with the form or bed it, performs the operation of cutting and creasing the blank sheets into a pluralit of folding box blanks. After the box blanks have been formed, the cut and creased sheets are transferred by means of the drop rollers H and stripper fingers is to present them to the delivery mechanism.

Immediately after the leading edge of a processed sheet passes the point or tangency between the rollers ii and the cylinder H,.these rollers move into their operative position in contact with sheet on the cylinder. Simultaneously with the movement of the rollers 51, the leading edge of the sheet is released by the cylinder grippers l2 the stripping fingers 48 move to their position in close proximity to the cylinder.

By pressing the sheet against the peripheral surface of the cylinder the rollers i? create friction whereby the leading edge of the sheet is pushed through the intervening space between the cylinder H and the chain delivery with the fingers i8 guiding the sheet onto the supporting cars 29 as shown in Figure 1.

Because the peripheral speed of the cylinder i l is slightly greater than the lineal speed of the chain conveyor, the gripper edge of a sheet is urged against the front guides or sheet aligning elements 23 and is maintained in contact with said guides until gripped by the delivery fingers 22. By means of the adjustable cam 23 the gripper fingers 22 are timed to close on the on- 8 coming sheet immediately before its trailing edge passes beneath the rollers ll. Consequently, control of the sheet is maintained While it is being transferred from the cylinder to the chain conveyor.

The supporting bars 26 are located in a position wherein they guide the gripper edge of the sheet into the bite of the open delivery gripper pads and associated fingers.

As the sheet is being conveyed to the delivery pile table the trailing portion of it is supported on the carriage 29 which reciprccates in the tracks 35 from theposition shown in Figure l to that illustrated in Figure 2, namely directly above the pile support Hi3. At this point the leading edge of the sheet is guided into the bite of the open stacking device gripper jaws Ed and 35 preparatory to its being deposited onto the pile. For the purpose of accurately ali ning the stacking device grippers with the leading edge of the sheets to be delivered, the stops 45 and ll, see Figure 3, are provided, which stops can be adjusted to either raise or lower grippers. This adjustment is made when the s iolring device is being installed on a press and it provides a permanent setting.

spectively as hereinabove described.

The clockwise movement of shaft 5' gripper jaws 3 3 and 35 to move a o a in a direction relative to that of the at the same speed until the roller low part E l of cam 6i causing lever b the spring 58, to move in a clcclmticn and thereby imparting a counter cl motion to jaw 35 through the connecting rod it closes on the sheet. chain grippers 22 are timed to release the at th moment when the stacking grippers close on The opening or" the delivery grippers is preferably accomplished by conventional cam means, not shown, which may be similar to the canwhereby these grippers are actuate to c the sheets or blanks prior to being delivers i. The counter-clockwise movement of is transmitted through lever ll) spring 52 to lever 38 and thereby to the connecting which moves the grippers 3d and 3E and stats finger i l downwardly while maintaining horizontal position as shown in Figure silient spring means 42 are used to tra-lsinit movement of lever 49 to lever 35 as precautienary measure in the event some in erference might prevent free movement of the grippers and 3-5 to their sheet depositing position. that case all movement of lever would no absorbed by spring 42 and no damage would he done to the mechanism. This also permits the grippers to automatically adjust themselves compensate for variations in the pile heshock which might otherwise be traz through shaft 39 to the gripper jaws a1 at the start of their downward movement which might cause the sheet to slip in the gr jaws, thereby adversely affecting its postwith respect to the accumulating pile.

from under the trailing portion of the deliw sheet. During the downward movement of t c grippers 3t and 35 the depending portion of holder ll contacts the lever causing holder H and the stacking finger T4 to rock counterclockwise on pin 36. This action, and while said grippers are still closed, causes the tip of finger I i to engage and depress the tab 15, see Figure 4, into interlocking relation with the previously de livered sheets after the sheet has been deposited in aligned relation with the sheets already on the pile, thereby firmly locking the stacked sheets together to prevent any disturbance of the aligned blanks during their removal from the press for the stripping operation.

The stacking device remains in this retracted position until the trailing portion of the delivered sheet has dropped into position on the pile at which time, by virtue of the contour of cam 8!, a counter-clockwise motion is imparted to shaft 59, causing the high part as of cam to move under and raise the roller 50 thereby transmitting a clockwise movement to the gripper through lever 56 and rod 53 which releases the leading edge of the delivered sheet.

This counter-clockwise movement of shaft 68 also moves lever Hi from its position beneath the depending portion 12 of holder 7! allowin the holder and finger M to drop to a horizontal position with the finger M raised free of the sheet. Immediately thereafter, by virtue of the contour: of cams 32 and 83, shaft 5i? is given a further clockwise movement while shaft 39 moves a relative amount in a counter-clockwise direction until ripper 34% is moved out from under the delivered sheet after which the action of the shafts is reversed and the stacking mechanism is returned to its sheet receiving position.

To look the device in its inoperative position, the spring i it is depressed past the projecting knob lit causing the edge I25 and lip H2 2 to ride on the peripheral surfaces of the collars S22 and we until the stacking mechanism moves to its retracted position. Then urged by the pressure of spring H8, lip I24 drops into notch E25 as edge 25 moves into notch E23. In this position the lever [it holds the shafts 39 against any movement in clockwise direction and the shaft 58 against any movement in the counterclockwise direction against the tension exerted by the springs it? and 99 respectively, see Figure 6, thereby preventing the return of the stacking device to its sheet receiving position.

To release the device from its locked relation, the spring H8 is returned to its position above the knob i it and when the actuating mechanism again reaches the retracted position in which the pressure of springs 99 and [01 is removed from the lip 82c and edge I25, spring H8 will urge lcver M6 in a clockwise direction away from the collars H20 and H2 thereby releasing the stacking mechanism for continued operation.

While we have disclosed herein a preferred embodiment of our invention, it shall be understood that many modifications in design and function may be introduced without departing from the basic principles involved, therefore it is our aim to cover any such features that will come within the scope and meaning of the appended claims.

We claim:

1. In combination with a cutting and creasing press for producing carton blanks and similar articles, a stacking device including, a chain delivery having gripper elements thereon, means for conveying sheets of processed blanks from the press to said elements in aligned relation thereto, a reciprocating carriage for supporting the sheets while being conveyed by said chain delivery, stacking grippers operative to receive the sheets from said gripper elements, a support, means to operate said stacking grippers to deposit the sheets in superposed relation onto said support, and means mounted to move with the stacking grippers to engage the deposited sheets and interlock them in aligned, stacked relation.

2. A stacking device as set forth in claim 1, in which the means for interlocking a sheet with previously deposited sheets is actuated while the sheet is still in the bite of the stacking grippers.

3. In a device for stacking die out sheets of carton blanks in superposed, interlaced relation on a pile support, the combination comprising, a plurality of stacking grippers, mechanism for actuating said grippers to engage each succeed-- ing die cut sheet and deposit it in aligned relation on the support, said grippers maintaining their bite on the sheet until the leading edge is firmly in position on the support, a stacking finger mounted on each gripper for movement therewith, and means incorporated in said mechanism for actuating said fingers to thereby depress selected portions of said sheet into interlocking relation with previously deposited sheets on the support before said grippers release their bite on the sheet.

4-. In a device for stocking die cut sheets of carton blanks on a pile support, the combination comprising, conveying meansfor transferring individual die out sheets to a position adjacent the pile support, a plurality of stacking grippers having a sheet engaging position wherein they en gage sheets carried by said conveying means and a sheet depositing position wherein they place the sheets onto the support in aligned relation, mechanism for actuating said stacking grippers in timed relation to said conveying means, a stacking finger pivotally mounted on and movable with each stacking gripper for depressing portions of each sheet into interlocking relation with the previously delivered sheets, and means associated with said mechanism for actuating said fingers each time the grippers are in their sheet depositing position.

5. A device as set forth in claim 4, wherein said stacking fingers are actuated to thereby interlock the last deposited sheet with the previously delivered sheets before said last sheet is released by said grippers.

6. In a device for stacking die cut sheets of carton blanks in superposed, interlocked relation on a pile support, the combination comprising an endless conveyor for conveying sheets to the pile support, a reciprocating carriage having op eration to support the trailing portion of each sheet as it is conveyed to and deposited onto said pile support, a series of stacking grippers, mech anism for actuating said grippers to take sheets from said conveyor and stack them in aligned relation on said support, and means pivotally mounted adjacent each of said grippers and mov able therewith, for depressing tabs formed in said sheets whereby each succee ding sheet is interlocked with previously delivered sheets on the piie support while still in the bite of said grippers.

'7. In a device for stacking die cut sheets of carton blanks in superposed, interlocked relation on a pile support, the combination comprising a series of stacking grippers for engaging succes--- sive sheets and depositing them in aligned relation on the support, mechanism for actuating said grippers including cam means for moving them from their sheet engaging position to their sheet depositing position and thence to a withdrawn position wherein they are removed from contact with the deposited sheet, and resilient spring means for returning them to their sheet engaging position, a stacking finger pivotally mounted on and movable with each stacking gripper for depressing tabs formed in said sheets to thereby interlock the successive sheets in aligned relation on the support, means associated with said mechanism for actuating said fingers while the grippers are in their sheet depositing position, and inanualiy operable locking means associated with said mechanism for locking the stacking grippers and therewith the fingers in their withdrawn position against the pressure of said resilient spring means.

8. In combination with a cutting and creasing press for producing carton blanks and similar articles, a sheet stacking device including, a chain delivery having gripper elements thereon, means for conveying sheets of processed blanks from the press to said elements in aligned relation thereto, a plurality of guides mounted on said gripper elements for registering the sheets before they are gripped by said elements, a reciprocating carriage having coac'tion with said chain delivery to support the trailing portion of the sheets while they are being conveyed by said chain delivery, stacking grippers operative to receive the sheets from said gripper elements, a pile support onto which said sheets are deposited, drive means for actuating said stacking grippers to deposit each succeeding sheet in superposed relation onto said support, a stacking finger pivotally mounted for movement with each stacking gripper, mechanism for actuating said fingers to engage each successive sheet as it is deposited onto said sup port whereby to interlock it in aligned relation with the preceding sheets, and while said sheet is still in the bite of the stacking grippers, and manually operable means associated with said drive means and operative when actuated to look the stacking grippers and therewith the stacking fingers in an inoperative position while the press and sheet conveyor continue operation.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 387,768 Cottrell Aug. 14, 1888 451,168 Cottrell Apr. 28, 1891 970,366 Barber Sept. 13, 1910 1,643,482 Zimniewicz Sept. 27, 1927 1,847,741 Zent Mar. 1, 1932 1,854,775 Wi'chmann Apr. 19, 1932 2,106,199 Wormser Jan. 25, 1938 2,203,978 Harrold et a1 July 23, 19%0 2,401,270 Pelikan May 28, 1946 2,467,973 Gannon et a1 Apr. 19, 1949 FOREIGN PATENTS Number Country Date 27,242 Great Britain of 1909 148,673 Great Britain Aug. 5, 1920

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