US3252640A

US3252640A - Web propelling cylinders for high speed web processing machines

Info

Publication number: US3252640A
Application number: US436565A
Authority: US
Inventors: William F Huck
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-03-02
Filing date: 1965-03-02
Publication date: 1966-05-24
Anticipated expiration: 1983-05-24

Description

W. F. HUCK May 24, 1966 WEB PROPELLING CYLINDERS FOR HIGH SPEED WEB PROCESSING MACHINES 2 Sheets-Sheet 1 Filed March 2, 1965 REGISTER PANEL CONTROL Fig.1

INVENTOR WILLIAM F. HUCK N 0 Wm m flu 0+ F W. F. HUCK May 24, 1966 WEB PROPELLIN'G CYLINDERS FOR HIGH SPEED WEB PRQCESSING MACHINES 2 Sheets-Sheet 2 Filed March 2, 1965 INVENTOR WILLIAM F. HUCK BY:

ATTORNEYS United States Patent 0 3,252,640 WEB PROPELLING CYLINDERS FDR HIGH SPEED WEB PROCESSING MACHINES William F. Huck, 81 Greenway Terrace, Forest Hills, Long Island, N.Y. Filed Mar. 2, 1965, Ser. No. 436,565 12 Claims. (Cl. 226-175) This invention relates generally to machines for subjecting flexible webs such as 'webs of paper, cardboard, cloth, plastic or metal foil, or the like, while traveling continuously at high speeds, to processing operations such, for example, as perforating, sheet-forming or other transverse cutting or forming operations. This application is a continuation-in-part of the co-pending application Serial No. 180,585, filed March 19, 1962, by William F. Huck, now United States Patent No. 3,174,372.

The invention relates more particularly to machines in which there is maintained a substantially constant tension in a web traveling continuously to and about a rotary cylinder that propels and processes the web; or in which the web is maintained in registering relation to processing elements, such as cross-cutting elements or perforating dies carried on the web propelling cylinder, when a Web bearing printed areas or other repetitive patterns is being processed.

Web processing machines of the type for which the present invention is intended are described and claimed in the co-pending application of William F. Huck, Serial No. 28,609, filed May 12, 1960, now United States Patent No. 3,174,428. In such machines, a flexible web is drawn continuously under tension, as from a printing press, an unwinding rollstand or some other suitable source of supply, to and about the periphery of a rotary cylinder that continuously propels the webs and carries web processing elements to act periodically upon the web; the web traveling to said cylinder is positioned by a displaceable roller which itself is positioned according to the tension or according to a register condition on the web; and the web propelling cylinder is provided with radially displaceable members which form parts of its peripheral surface, and which are displaced radially upon and in proportion to displacements of said roller so as to vary compensatingly the web engaging circumference of said cylinder and thus the speed of its propulsion of the web. By virtue of this arrangement, the speed of propulsion of the web by the rotary cylinder that is also periodically cutting or otherwise deforming the web can be varied automatically in com ensation for a variation of the tension of the web, or in compensation for a register variation when the web being processed is one having repetitive patterns thereon to be kept in register with the processing elements on the rotary cylinder.

The cylinder that propels the *web often is the first of two coacting cutting cylinders which form a couple to cut the web, as by perforating it or cutting it transversely into sheets, in a zone of tangency between the two cylinders. Each of the two cylinders then has web cutting elements spaced apart thereon so as to coact in said zone with mating web cutting elements on the other cylinder, and the radially displaceable members are disposed in between the web cutting elements on the cylinder that propels the Web.

In a machine adapted for perforating the web, the cylinder that propels the web preferably has female die elements thereon to coact with mating pins on the second cylinder.

In a machine adapted for cutting the web into sheets, the cylinder that propels the web preferably has crosscutting knives thereon which coact with mating anvil elements on the second cylinder to sever the web crosswise into a succession of separate sheets.

It is an object of this invention to provide an improved web propelling cylinder for Web processing machines of the described character, which cylinder has an increased capacity and sensitivity in compensating for a variation of the tension of the web or in compensating for a register variation when the web being processed is one having repetitive patterns thereon to be kept in register with the processing elements on the rotary cylinder so that, even though the web may be traveling continuously at a high speed, it can be cut into sheets, perforated or subjected to other cutting or forming operations with assurance that the required accuracy of the operations will be maintained.

Another object is to provide a web propelling cylinder of the described character in which the radially displaceable members are formed so as to constitute a major proportion of the circumference of the cylinder, thereby to provide a relatively large variation of the circumference of the cylinder, and hence in the speed at which the web is propelled, in response to the controlled radial displacement of the members.

Still another object is to provide each radially displaceable member of the web propelling cylinder with a relatively large area of contact with the web so that variations of the tension in the web give rise to relatively large changes in the forces acting on the radially displaceable members and thereby increase the sensitivity to such tension variations, and further so that forces applied to the web upon radially outward displacement of the memher are distributed over relatively large areas of the web to avoid tearing or other damage thereto.

A further object is to provide a Web propelling cylinder of the described character having an improved mounting and actuating arrangement for its radially displaceable members so as to increase the accuracy and sensitivity of its compensation for web tension or register variations.

In accordance with an aspect of this invention, the radially displaceable members, which extend axially on the web propelling cylinder, are of T-shaped cross-section to each provide a relatively wide head having a suitably arcuate outer face that forms a considerable segment of the peripheral surface of the cylinder.

In accordance with another aspect of the invention, the radially displaceable, surface-forming members of the web propelling cylinder are mounted on the body of the cylinder by means of leaf springs which are inclined with respect to the axis of the cylinder so that radial movements of the surface-forming members are accompanied by corresponding axial displacements thereof and the leaf springs continuously exert forces entering into the balance of forces determining the radial positions of the surface-forming members.

The above and other important objects, features and advantages of the invention will be apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. In the drawings:

FIG. 1 is a schematic side elevational view, partly broken away and partly in section, of a high-speed web sheeting machine having a web propelling cylinder embodying the invention;

FIGURE 1a is a schematic view showning an alternative arrangement of the displacea-ble rollers in such a machine;

FIG. 2 is a transverse sectional view taken along the line 22 on FIG. 1, but on an enlarged scale; and

FIG. 3 is an enlarged fragmentary sectional View showind details of a Web propelling cylinder in accordance with the invention.

Referring initially to FIG. 1 of the drawings, it will be seen that the invention is there shown embodied in a high-speed web sheeting machine which is intended to receive a continuous flexible web W of relatively thin material, such as paper, cardboard, cloth, plastic or metal foil, or the like, delivered continuously to the machine at a high speed, to cut the web into successive sections or sheets of uniform size, and to deliver these individually away from the cutting zone as rapidly as they are formed.

The web W may be received by the machine shown directly from a rotary web printing press or other machine by which it has been previously printed or otherwise processed; or it may be drawn continuously from an unwinding rollstand or other suitable supply source. It will be understood that the machine shown is driven in synchronism with the printing press, rollstand or other source of the web. The web may be composed of a single layer or ply of the paper or like material; or it may be a multi-ply web such as may be formed, for example, by slitting a web or webs into ribbons and assembling the ribbons into a continuous flexible strip. Further, a plurality of separate webs or ribbons, such as may be formed by slitting a wide printed web into narrower strips or ribbons each having the width of a printed book or magazine page, may be processed simultaneously in side by side relation in the machine.

The machine shown comprises a rotary cutting mechanism -12 composed of first and

second cylinders

13 and 14, respectively, which are journalled at their ends in suitable bearings carried by side frame members 11 (FIG. 2). The two cylinders are rotated in contiguous relation about parallel, horizontal axes, so as to provide between them a zone of tangency Z in which cross cutting operations will be performed periodically upon the web W to convert the web continuously into a succession of separate sheets.

The first cylinder 13, which constitutes the web propelling cylinder embodying this invention, includes a generally cylindrical body 15 which, in the machine shown, has one or more axially extending recesses 16 in the periphery thereof at locations spaced apart equally about its circumference. Each recess 16 receives a cutting blade or knife 17 which is held in the related recess by a wedge or clamping block .18 secured to body 15, as by screws 19 (FIG. 3). Although the cylinder 13 is shown with three knives 17 thereon, it is to be understood that a larger or smaller number of knives may be carried by that cylinder, depending upon its circumference and the length of the successive sections or sheets to be cut from web W, which length is equal to the circumference of cylinder [13 divided by the number of knives .17 thereon.

The second or transfer cylinder 14 of the cutting mechanism is shown to include a cylindrical body 20 (FIG. 1) having a plurality of axially extending recesses or slots 21 in its periphery, which are equal in number to the recesses 16 in the body of cylinder 13 and are also equally spaced apart in the circumferential direction. The recesses or slots 21 accommodate elongated anvil members 22 which are urged radially outward, as by springs 23 (FIG. 3). The radially inward and outward movements of anvil members 22 are limited by set screws 24 which are received in offset tapped bores 25 formed in body 20 so as to open into each slot 21. The offset set screws 24 have conical points 26 which engage in conical sockets 27 formed in the related anvil members 22 and having greater :base diameters than the conical points of screws 24.

The cylinder 13 is suitably rotated in the clockwise direction as viewed in FIG. 1; for example, through a suitably rotated drive gear 28 (FIG. 2) meshing with a gear '29 fixed on a trunnion extending from one end of cylindrical 'body 15. The second or transfer cylinder '14 is rotated at the same. angular speed as cylinder 13, but in the counterclockwise direction as viewed on FIG. 1; for example, through a gear (not shown) fixed on a trunnion extending from an end of cylindrical body 20 and meshing with the previously mentioned gear 29.

Although the

cylinders

13 and 14 are counter-rotated at the same angular speed, cylinder 14 may be made, as shown, to have a diameter substantially greater than that of cylinder 13, so that the peripheral or circumferential speed of cylinder 14 is considerably greater than that of cylinder 13. However, since the two cylinders have the same numbers of coacting knives 17 and anvil members 22 and are rotated at the same angular speed, the meshing gears thereof, which are preferably of the antibacklash type, can be brought into meshing engagement with each other so as to ensure that each knife 17 will move through the zone of tangency Z between the cylinders simultaneously with a related one of the anvil members 22, as indicated in FIGS. .1 and 3.

'In the machine shown on FIG. 1, the web W passes downwardly to and travels around the lower peripheral portion of the first cylinder 13 in wrapped relation thereto before reaching the zone of tangency Z between the two cylinders, so that the web can be kept in non-slipping relation to cylinder 13 and will be advancedto the zone of tangency at the circumferential speed of that cylinder. The part of the web thus wrapped upon the cylinder 13 is held tightly against the same in a fixed position with respect to a knife or knives 17 thereon by suitable Web guiding means 31 (FIGS. v1 and 2).

" The web guiding means 31 as shown include a plurality of flexible belts 32 which are trained about pulleys 33 and 34 mounted for free rotation on shafts located respectively at the forward and backward sides of cylinder 13. The belts thus have a flight 32a thereof which extends arcuately between the pulleys 33 and 34 and over the web W in wrapped relation to the lower peripheral portion of cylinder 13. As indicated in FIG. 2, there may be an individual web or ribbon held in place by each belt 32. The belts travel out of their arcuate flight 32a into a return flight that is constantly held under a tension sufiicient to keep the arcuate flight pressed tightly against and moving with the periphery of cylinder 13, as by tensioning pulleys 35 which are rotatably journalled in arms 36 (FIG. 2) that extend radially from an axle 37 journalled in the side frame members 11. A radial arm 38 (FIG. 1) on one end of axle 37 is connected to a spring 39 which is anchored to the adjacent side frame member 11 so as to urge axle 37 constantly in the direction for tensioning the belts 32.

It will be evident that the length of the sheets cut from the web or webs W by the action of the cutting elements in zone Z is governed by the circumferential distance at the periphery of cylinder 13 between the successive cutting elements 17 carried by that cylinder.

For accurate maintenance of the desired size of the sheets cut from the web it is important that the web be drawn continuously to the rotary cutting mechanism 12 under a substantially uniform predetermined tension, notwithstanding the tension varying effects of changes in environmental conditions or of variations of physical qualities of the web. Furthermore, in order to keep the cutting elements acting upon a printed or otherwise repetitively patterned web at the proper locations relative to the printed areas or other patterns on the web, the illustrated machine is provided with suitable register control means and with means for maintaining the required web tension notwithstanding register correcting actions of the register control means.

As shown in FIG. 1, the web propelling cylinder 13 is provided with radially displaceable members 40 which form parts of its peripheral surface engaging the web W; the web traveling to cylinder 13 is passed about and positioned by a displaceable roller 68 which is biased yieldably against the web under a predetermined force, such as that of a spring 72, so as to tension the web to the desired extent; and positioning means are provided, such as the system of levers and links seen between the roller 68 and cylinder 13 in FIGS. 1 and 2, to displace the members 40 radially relative to the axis of cylinder 13 upon and in proportion to displacements of the roller 68. By virtue of this arrangement, the effective diameter and web engaging circumference of the cylinder 13 and thus the speed of its propulsion of the web are varied automatically in compensation for variations of the tension of the web approaching the cylinder; for an incremental reduction of this tension is attended by a displacement of roller 68 that causes a compensating increase of the web propelling circumference of cylinder 13, while an incremental increase of the web tension is attended by a reverse displacement causing a compensating decrease of the speed of propulsion of the web.

As shown particularly on FIG. 3, the radially displaceable members 40 of cylinder 13 are, in accordance with this invention, of T-shaped cross-section so as to each include a relatively narrow, radial stem or flange 40a and a relatively wide head 4% extending across the outer end of the stem or flange. The radially displaceable members 40 are disposed between the knives 17 on cylinder 13 and have their stems or flanges 40a slidably received in axially extending slots 41 which open radially outward at cations spaced apart about the periphery of the cylindrical body 15. The wide head 40b of each member 40 has a suitably arcuate outer face that forms a considerable segment of the peripheral surface of the cylinder 13.

As shown in FIG. 2, each member 40 of the cylinder 13 embodying this invention is mounted within its slot 41 by a plurality of inclined leaf springs 42 which have their outer ends secured to the displaceable member 40 and their inner ends secured to the cylindrical body 15, and which constantly urge the member 40 toward the left and radially inwardly as viewed in FIG. 2. The opposite ends of each member 40 extend loosely into undercut

rings

43 and 44 provided on the opposite ends of body 15, and helical compression springs 45 act between these rings and the ends of each member 40 to further urge the latter radially inward. The ring 43 is fixed in place, while the ring 44 is movable axially relative to the body and is provided with an inturned flange 46 which engages into a notch 47 at the adjacent end of each member 40. The displaceable members thus are positioned by and constrained to follow any axial displacement of the axial movable ring 44.

The position of the ring 44 and members 40 is determined by a mechanism 48 (FIG. 2) connected with the displaceable roller 68. This mechanism includes a shaft 50 which is axially slidable within an axial bore 52 at one end of body 15 and which carries radial rods 54 that pass loosely through passages 56 in body 15 and have their outer ends engaged in suitable sockets in ring 44. The

outer end of shaft 58 carries an anti-friction bearing 58 on which there is mounted the hub of a radially extending arm 60 so that shaft 50 can rotate with cylinder 13 independently of the radial arm 60. A housing 62 fixed around bearing 58 has follower rollers 64 mounted therein in engagement with a cam ring 66 suitably secured at the inside of arm 60 around the hub of this arm.

It will be apparent that the springs 42 and constantly urge the members 40, ring 44, rods 54 and shaft 50, as a unit, axially toward the left as viewed on FIG. 2, that is, in the direction tending to retract shaft within cavity 52. Therefore, the cam ring 66 is constantly urged against the follower rollers 64, and any angular displacement of arm on bearings 58 is effective either to displace shaft 50 and members 40 toward the right, as viewed on FIG. 2, or to permit the members 40 to be displaced toward the left by the force of the

springs

42 and 45. When the members 40 are displaced toward the right they move radially outward on the inclined mounting springs 42, thus increasing the effective circumstance of cylinder 13; and when they are displaced toward the left they move radially inward to decrease that circumference.

As further seen in FIG. 1, the illustrated machine has the displaceable roller 68 journalled in arms 70 which extend generally upward from a rockable shaft 71. The tension spring 72 biasing this roller against the web is connected at one end, as at 73, to one of the arms 70 and at its other end, as at 74, to a rockable arm 75 secured on a shaft 76. Another arm 77 secured to shaft 76 carries a pivotal nut 78 having an adjusting screw 79 threaded through it, so that a rotation of this screw, as by a knob 81 on its end, will change the position of arm 75 and thus vary the force exerted by spring 72 upon arm 70, hence the force exerted by roller 68 against the web W and the tension to be maintained in the web.

The shaft 71 which carries the arms 70 and roller 68 has another radial arm 82 secured to it for movement with that roller. This arm is pivotally connected at 84 to a link 83 that extends downwardly to a pivotal connection at 85 with the radial arm 60 of the above-described mechanism 48, so that any displacement of the roller 68 is attended by a proportionate angular displacement of the arm 60 and cam ring 66 and thus by a proportionate variation of the radial position of the displaceable members 40 of cylinder 13. A dashpot 86 pivotally mounted at 87 on the frame of the machine has its piston rod 88 pivotally connected at 89 to the end of arm 82, and serves both to reduce any tendency of the floating roller 68 to hunt during operation and to prevent shocks in the mechanism 48 in the event of a break in the web W.

It will be evident that, in the above described arrangement, the forces exerted by the

springs

42 and 45 on members 40 and tending to move the latter radially inward balance the resultant of the tension in web W and the adjustable tension control force exerted by the spring 72. If the tension of web falls below the desired value determined by the adjustment of spring 72, that spring displaces roller 68 toward the left as viewed in FIG. 1 and causes axial displacement of shaft 50 in the direction for effecting radially outward displacement of the members 40, thereby increasing the effective diameter and peripheral speed of the cylinder 13 and correspondingly increasing the tension in the web until the tension variation is corrected and the renewed balance of forces restores the roller 68 to its normal operating position. Conversely, if the web tension increases beyond the desired value, the roller 68 is displaced toward the right as viewed on FIG. 1, and the corresponding angular displacement of arm 69 and cam 66 permits a corresponding inward movement of the members 40 by the springs 42. and 45 and by the force of the tensioned web acting radially inward on members 40, which inward movement of members 40 decreases the effective diameter and web propelling speed of cylinder 13 so as to decrease the tension in the web until the tension variation is corrected and the roller 68 is returned to its normal operating position.

A pointer 90 (FIG. 1) on shaft 71 cooperates with a scale 91 to indicate constantly the position of the displaceable roller 68.

The above described mechanism including a web propelling cylinder embodying the invention responds instantaneously to tension variations in the web being propelled to the cutting cylinders and corrects them automatically as and whenever they may occur, thus ensuring that the web will be wrapped upon and drawn by cylinder 13 under substantially the required tension at all times. It results that the cuts made across the web or webs in zone Z can continue to form sheets of substantially the required size even when there are variations of environmental conditions or of physical qualities of the web material and even during operations of the cutting cylinders at very high speeds.

The web propelling cylinder embodying the invention is further ideally suited for use in the described mechanism when the latter is moreover adapted to maintain repetitive patterns on the web in the required registering relation to the cutting elements on cylinder 13 when a printed web or the like is being processed by the machine.

For this purpose, as shown in FIG. 1, the'web W traveling to the first cutting cylinder is passed about a roller 200 which is positioned adjustably by a reversible register correction motor 208. The roller 200 is mounted in arms v201 secured to a shaft 202, and another arm 203 on the same shaft carries a pivotal nut 204 which receives and is positioned by a screw 205 on the rotary shaft 206 of the motor 208.

The motor 208 constitutes one element of a register control system, of a character known per se, which continually compares the angular position of the cylinder 13, hence the position of the knives 17 thereon, with the positon of register marks M located on the web W and which acts, upon sensing a deviation from the required registering relationship of these positions, to displace the roller 200 in the direction and to the extent required for correction of the sensed register error. This register control system also comprises a photoelectric scanning head 210, a pulsing switch 220, a register control panel 230, and suitable

electrical connections

231, 232 and 233 between the panel and the other elements of the system.

The scanning head 210 detects the register marks M on the web and emits control signals as these marks pass by a fixed scanning station 212 on their way to cylinder 13. A light source 213 in the head casts a beam onto the web for reflection into a photoelectric detection cell 214 by which a signal is sent to the register control panel whenever a register mark M intercepts the light beam.

The pulsing switch 220 comprises a slotted disk 221 which is rotated in a fixed positional relationship to the rotation of cylinder 13, through a pulley 222, a timing belt 223, a driving pulley 224 and a driving shaft 225 geared for rotation with the cylinder 13. A light beam from a source within switch 220 passes through a slot or slots in the disk 221 to a photoelectric cell in the switch, thus generating signals which are emitted from the switch 220 to the control panel 230 at intervals which give a precise measure of the angular position and speed of the knives on cylinder 13.

At the outset of the operations of the machine, the web W is so positioned relative to the scanning head- 210 and the register control system is so regulated that when the web wrapped on cylinder 13 is correctly registered with one or more of the knives 17 thereon, i.e., when it overlies a knife so as to be severed at the correct location between two of the successive printed areas or other patterns on the web, the signals generated by the movement of the register marks past the scanning head 210 will coincide with the signals generated by the pulsing switch 220.

In the course of the cutting operations, whenever the register marks M passing the scanning station 212 run ahead of, or lag behind their position that corresponds to correct registration of the web with the knives 17, the deviation is detected by the register control panel, and an error signal proportional to the deviation is emitted from the panel to the register correction motor to energize the motor 208 in the direction for correction of the register error.

Thus, if the register marks and patterns on the web are running ahead of the correct position, the motor is energized so as to displace roller 200 toward the right as viewed in FIG. 1. This displacement causes an incremental increase of the web tension acting upon the displaceable roller 68, whereupon roller 68 is displaced proportionately to the right and, through the link 83 and mechanism 48, the radially displaceable members 40 of cylinder 13 are displaced inwardly to reduce proportionately the circumference of cylinder 13 and the length of the web being entrained upon this cylinder from one knife 17 to the next knife. The desired locations for the cuts of the web thus are brought back to the correct positions over the knives on the cutting cylinder, and at the same time the web tension is reduced so that roller 68 will return to its normal working position.

Conversely, if the register marks and patterns on the web are lagging behind the correct position, the motor displaces roller 200 toward the left, the web tension thus is incrementally reduced, roller 68 is displaced to the left, and the circumference of cylinder 13 is increased proportionately so as to take up an increased length of the web between the knives and thus advance the desired locations for the cuts of the web to the correct positions over the knives. Again, the action resulting restores the web tension to its normal value.

While in the machine shown on FIG. 1 the roller positioned by theregister control system acts indirectly through its influence upon the tension of web W, and thus upon the position of a displaceable roller biased yieldably against the web, the web propelling cylinder 13 embodying this invention can also be employed in an arrangement utilizing a roller positioned by the register control system as the displaceable roller that controls the effective circumference of the expansible web processing and propelling cylinder.

For example, as shown schematically in FIG. 1a, the traveling to the cutting mechanism 12 is passed about a displaceable roller 200a that is positioned by a reversible register correction motor 208a in essentially the same manner as the roller 200 of FIG. 1; and the roller 200a is connected directly, as by arm 203a, shaft 202a and arm 82a, to the link 83 of the mechanism 48 that positions the radially displaceable members 40 of cylinder 13.

In order that the register correcting displacements of roller 200a will not materially alter the length of the path or tension of the web W, a web tensioning roller 68a is biased yieldably against the web at a location either preceding roller 200a, as seen in FIG. 1a, or between the roller 200a and cylinder 13. This biased roller is carried by arms 70a from a shaft 71a from which another arm 73a extends radially to pivotal connections with the plunger of a dashpot 86a and the piston of a fluid pressure cylinder 72a. Air under a predetermined pressure admitted through duct 74a to the base of the fluid pressure cylinder keeps roller 200a bearing against the web with a constant force so that this roller will change its position automatically in response to variations of the length or tension of the web.

Therefore, in the arrangement of FIG. 1a, register errors in the web travelling to the cutting mechanismv are corrected automatically in essentially the same manner as in the embodiment of FIG. 1; and throughout the operations, for as long as web displacements do not exceed the range of movement of roller 68a, the tension of the web is kept substantially at the value determined by the fluid pressure in cylinder 72a. In the event that a greater range of tension control is required, it can be provided by the use of a biased web tensioning roller forming part of a web-propelling tension control mechanism of known construction.

In the operation of the arrangement according to FIG. 1a, if the register marks M on the web are running ahead of the correct position, the motor 208a is energized so as to displace roller 200a toward the left as viewed in the drawing. This displacement causes the radially movable members 40 of the cylinder 13 to be displaced inwardly to reduce proportionally the circumference of cylinder 13 and the length of web entrained on this cylinder from one knife 17 to the next knife. The leftward displacement of roller 200a will cause a transient increase in web tension that is immediately counteracted by a displacement of the roller 68a and the slidable piston within fluid pressure cylinder 72a. The desired locations of the cross cutting operations performed on the web thus are restored to their correct positions over the knives on the cutting cylinder, by a combination of a backward displacement of the web and a proportional decrease of the web speed, and at the same time the change of web tension that otherwise would result from the displacement is absorbed by movement of the roller 68a.

Conversely, if the register marks are lagging behind their correct position, the motor 268a displaces roller 200a toward the right, and the circumference of cylinder 13 is increased proportionally so as to take up an increased length of the web between knives 17, and thus advance the desired locations of the cross cutting operation on the web to their correct positions over the knives by a combination of z t-forward displacement of the web and a proportional increase of the web speed; and, again, the change of Web tension that otherwise would result is absorbed by a displacement of roller 68a.

Re-ferring further to FIG. 1, it will be evident that, upon each convergence of a knife 17 on cylinder 13 with an anvil member 22 on cylinder 14 in the zone of tangency Z these elements cut transversely through the web W so as to sever from it the web portion advanced through zone Z since the making of the preceding cut. In the illustrated machine, the web portion advanced through the zone Z between the successive cuts is held to, but slipping on the faster moving surface of cylinder 14 under the influence of suitable holding means on this cylinder which draw to its surface the new leading end of the web formed by each cut and yet permit this new end to slip relative to its surface.

More particularly, the body of cylinder 14 is provided with an axial bore 92 opening through a trunnion at one of its ends and which is suitably connected to a source of vacuum. The peripheral portions of cylinder 14 between the anvil members are defined by arcuate plates 94 (FIGS. 1 and 3) which have air ports 95 formed therein over annular cavities 96 that communicate with the axial bore 92 through radial passages 97. Thus, a suitable suction applied through the parts 95 will draw a new end of the web in zone Z to the surface of cylinder 14 and yet will allow this end to slip on the faster moving cylinder surface until the next cut is made across the web.

The making of the next cut of course severs from the web a sheet S (FIG. 1) of the length determined by the peripheral distance between the successively acting knives 17 on cylinder 13. This sheet becomes free to move at the peripheral speed of cylinder 14 at the moment when it is severed from the following body of the web; so the suction applied to it through the ports 95 will then cause it to be carried away fromv zone Z at a speed greater than that of the new web end traveling behind it. It results that the successive sheets cut from the web are spaced apart and carried away separately at a high speed on the surface of cylinder 14.

For further assurance that each sheet S will be accelerated to the peripheral speed of cylinder 14 immediately upon being severed from .the web, the illustrated machine is provided with a gripping roller 98 (FIG. 1) which acts to press the sheet tightly against the surface of cylinder 14 when the cut is made. This roller has a segmental elastic flange 99 of rubber or like material, which is rotated into rolling contact with each sheet S on the surface of cylinder 14 at the instant when the sheet is severed from the web, and which is driven at the speed of that surface by a suitable belt drive 169. Accordingly, the relative inertia of the cut sheet is immediately overcome so that it will be propelled positively away from the cutting zone on the second cylinder. In addi tion, if the cut happens to leave a connection between the sheet and the trailing body of the web, this connection will be broken by the pull of cylinder 14 and roller 98 on the nearly formed sheet.

The removal of the sheets from the surface of cylinder 14 is effected, in the machine illustrated in FIG. 1, by means of a delivery conveyor 111 which comprises pulleys 112 on a shaft 113 over which belts 116 run in tangential relation to the surface of cylinder 14. The shaft 113 is driven in timed relation to the cylinder 14. The belts 116 carry finger-like grippers 119 which press against the belts while in the straight runs of the conveyor and are held open while carried around a pulley. The belts are driven at a speed less than the peripheral speed of cylinder 14 but with the grippers 119 so located on them that a.set of the grippers in open condition will extend into a recess located on cylinder 14 to underlie the leading edge of each sheet S, on that cylinder upon each movement of the grippers about the pulleys 112. The sheet thus is moved into the pocket formed by the open grippers, and it is gripped to the belts and peeled away from cylinder 14 for further delivery as the grippers 119 move into the lower runs of the belts 116.

Whether the expansible web propelling cylinder 13 embodying this invention is employed in a web sheeting machine, as shown, or in a machine subjecting the web to other processing operations, such as, perforating operations, and whether the members 40 of the cylinder are radially displaced in compensation for a variation of the tension of the web or in compensation for a register variation when the web being processed is one having repetitive patterns thereon to be kept in register with the knives 17 or other processing elements on cylinder 13, the construction and arrangement of that cylinder in accordance with this invention, as described above, ensures utmost accuracy and speed of response in compensating for tension or register variations without imposing excessive localized stresses on the web likely to cause tear ing thereof. The foregoing advantages are obtained by reason of the wide arcuate outer faces of the heads 40]) of radially displaceable members 40 each of which contacts the web over a relatively large area so that variations in web tension produce significant changes in the force applied radially inward by the web to the individual members 40. Further, the reaction to such force resulting from the web tension, and the oppositely directed force applied to the web when the members 41) are displaced radially outward, are distributed over a large area of the web so that tearing of the latter is not likely to occur. It will also be seen that the wide heads 40b of the radially displaceable members 40 form a substantial proportion of the peripheral surface of cylinder 13 so that, when the members 40 are radially displaced, there results a relatively large change in the effective circumference of the cylinder and in the speed at which it propels the web for improved responsivess in compensating for web tension or register variations.

The mounting of the radially displaceable members 49 by means of the inclined leaf springs 42 is advantageous in its relative simplicity and also in that each member 40 is thereby urged radially inward and axially in the direction for maintaining con-tact of cam 66 with rollers 64- to ensure the accurate correspondence of the radial positioning of members 49 with the positioning of the displaceable roller 68 or 200a. Further, the mounting springs 42 contribute to the balancing of the resultant force of the web tension and the force of the tension control spring 72 or of the fluid pressure cylinder 72a.

Although an illustrative embodiment of an expandible web propelling cylinder in accordance with this invention has been described in detail with reference to the accompanying drawings, it is to be understood that the invention is not limited to that precise embodiment nor to its employment in the described web processing machines, and that various changes and modifications can be effected in the described embodiment without departing from the scope or spirit of the invention as defined in the appended claims.

What is claimed is:

1. In a web processing machine having a rotary web propelling cylinder to which the web is guided so as to be wrapped around, and in frictional engagement with a substantial peripheral portion of the surface of the cylinder for advancement by the latter; said cylinder comprising a centrally disposed rotatable body, and a circumferentially arranged series of axially elongated mern-v bers which are spaced apart circumferentially and radially displaceable on said body, said members having circumferentially extended outer portions. constituting a major proportion of the circumference of the cylinder; and means including elements carried with and displaceable axially relative to said body for positioning said elongated members radially with respect thereto.

2. In a web processing machine having a rotary web propelling cylinder carrying web processing elements at circumferentially spaced locations and to which the web is guided so as to be wrapped around, and in frictional engagement with a substantial peripheral portion of the surface of the cylinder for advancement by the latter while being acted upon by the web processing elements; said cylinder comprising a centrally disposed rotatable body, and elongated members extending axially on said body between the web processing elements and being radially displaceable, said elongated members presenting circumferentially extended outer portions constituting a major proportion of the periphery of the cylinder; and means including elements carried with and displaceable axially relative to said body for positioning said elongated members radially with respect thereto.

3. In a web processing machine of the type in which a flexible web is drawn continuously under tension to and about the periphery of a rotary cylinder that continuously propels the web and carries spaced web processing elements to act periodically upon the web, and wherein the rotary cylinder includes a generally cylindrical body having circumferentially spaced, axial slots opening radially outward between the web processing elements and elongated members slidably received in said slots and being radially displaceable to vary the web engaging circumference of the cylinder and the speed of its propulsion of the web; the improvement that consists in each of said elongated members being of T-shaped cross-section and having a central flange extending into the related slot of the body and a relatively Wide head extending across said flange at the outside of said body, the heads of the elongated members constituting a substantial proportion of the area of the periphery of the cylinder and each head affording a relatively large area of contact with the web.

4. In a web processing machine of the type in which a flexible web is drawn continuously under tension to and about the periphery of a rotary cylinder that continuously propels the web; said cylinder comprising a generally cylindrical body, axially extending, elongated members spaced apart circumferentially on said body to each constitute a portion of the peripheral surface of the cylinder, leaf springs secured at their opposite ends to each of said elongated members and said body and being inclined with respect to the axis of said body, whereby said members are mounted for radial displacements relative to the body so as to vary the web engaging circumference of the cylinder and the speed of its propulsion of the web, and such radial displacements are accompanied by corresponding axial movements of the elongated members, and actuating means operable to determine the axial positions of said elongated members relative to said body and thus control said web engaging circumference of the cylinder.

5. In a web processing machine, a cylinder as in claim 4; wherein said leaf springs urge the respective elongated members radially inward and axially toward one end of said body; and wherein said actuating means includes a ring movable axially on said body and being coupled with said elongated members so that the latter follow the axial movements of said ring, an axially slidable shaft projecting from an end of said body and carrying radial rods passing loosely through radial pas sages in said body and engaging said ring to move the latter axially upon axial displacement of said shaft, bearing means on said shaft outside of said body, cammeans mounted on said bearing means so as to be axially movable with said shaft and turnable independently of the rotation of the cylinder, and follower means mounted at fixed locations adjacent said cam means and having the latter held in engagement therewith by the force of said springs urging said elongated members axially toward said one end of the body, so that radial displacement of said elongated members is achieved by turning of said cam means.

6. In a web processing machine, a cylinder as in claim 4 wherein each elongated member presents a relatively wide head at the outside of said body, the heads of the elongated members being spaced apart circumferentially yet constituting a major proportion of the periphery of the cylinder.

7. A web propelling cylinder comprising a generally cylindrical body having formed therein circumferentially spaced, axially elongated slots opening radially outwardly therefrom, and elongated members of substantially T-shaped cross-section each having a central flange slidably received in a related one of said slots and a relatively wide head extending across said flange at the outside of said body, the heads of said elongated members being spaced apart circumferentially and constituting a substantial proportion of the peripheral surface of the cylinder for varying the effective circumference of the cylinder in response to radial displacement of said elongated members.

'8. A web propelling cylinder as in claim 7; further comprising leaf springs connected at their opposite ends to said body and to said elongated members within said slots and being inclined relative to the axis of the body so that radial displacements of said elongated members are accompanied by axial movements thereof, and actuating means operative to move said elongated members axially in opposition to said springs for determining the effective circumference of the cylinder.

9. A web propelling cylinder as in claim 8; wherein said leaf springs urge the respective elongated members radially inward and axially toward one end of said body; and wherein said actuating means includes a ring movable axially on said body and being coupled with said elongated members so that the latter follow the axial movements of said ring, an axially slidable shaft projecting from an end of said body and carrying radial rods passing loosely through radial passages in said body and engaging said ring to move the latter axially upon axial displacement of said shaft, bearing means on said shaft outside of said body, cam means mounted on said bearing means so as to be axially movable with said shaft and turnable independently of the rotation of the cylinder, and follower means mounted at fixed locations adjacent said cam means and having the latter held in engagement therewith by the force of said springs urging said elongated members axially toward said one end of the body, so that radial displacement of said elongated members is achieved by turning of said cam means.

10. A web propelling cylinder comprising a generally cylindrical body having circumferentially spaced, axial slots opening radially outward, elongated members slidably received in said slots for varying the effective circumference of the cylinder in response to radial displacement of said elongated members, leaf springs connected at their opposite ends to said body and to said elongated members within said slots and being inclined relative to the axis of the body so that radial displacements of said elongated members are accompanied by axial movements thereof, and actuating means operative to move said elongated members axially in opposition to said springs for determining the effective circumference of the cylinder.

11. In a web processing machine of the type in which a flexible web is drawn continuously under tension to and about the periphery of a rotary cylinder that continuously propels the Web and carries spaced web processing elements to act periodically upon the web, and wherein the rotary cylinder includes a generally cylindrical body having a circnmferentially arranged series of axially elongated members displaceable radially thereon between the web processing elements to vary the web engaging circumference of the cylinder and the speed of its propulsion of the web; the combination of leaf springs connected at their opposite ends to said elongated members and said body and being inclined with respect to the axis of the cylinder to urge the elongated members radially inward and axially toward one end of said body, a displaceable r-oller engaged by the web traveling to the cylinder and being positioned in accordance with a condition of the web, and positioning means acting axially on said elongated members in opposition to the force of said springs to effect radial displacement of said elongated members upon, and in proportion to displacements of said roller.

References Cited by the Examiner UNITED STATES PATENTS 2,292,85l 8/1942 Tykal 226-186 X 3,174,372 3/1965 Huck 831l0 3,174,428 3/1965 Huck.

FOREIGN PATENTS 904,219 2/1954 Germany.

M. HENSON WOOD, 111., Primary Examiner.

JACOB N. ERLICH, Assistant Examiner.

Claims

1. IN A WEB PROCESSING MACHINE HAVING A ROTARY WEB PROPELLING CYLINDER TO WHICH THE WEB IS GUIDED SO AS TO BE WRAPPED AROUND, AND IN FRICTIONAL ENGAGEMENT WITH A SUBSTANTIALLY PERIPHERAL PORTION OF THE SURFACE OF THE CYLINDER FOR ADVANCEMENT BY THE LATTER; SAID CYLINDER COMPRISING A CENTRALLY DISPOSED ROTATABLE BODY, AND A CIRCUMFERENTIALLY ARRANGED SERIES OF AXIALLY ELONGATED MEMBERS WHICH ARE SPACED APART CIRCUMFERENTIALLY AND RADIALLY DISPLACEABLE ON SAID BODY, SAID MEMBERS HAVING CIRCUMFERENTIALLY EXTENDED OUTER PORTIONS CONSTITUTING A MAJOR PROPORTION OF THE CIRCUMFERENCE OF THE CYLINDER; AND MEANS INCLUDING ELEMENTS CARRIED WITH AND DISPLACEABLE AXIALLY RELATIVE TO SAID BODY FOR POSITIONING SAID ELONGATED MEMBERS RADIALLY WITH RESPECT THERETO.