US3577834A

US3577834A - Gripper bar mount for platen press

Info

Publication number: US3577834A
Application number: US782191A
Authority: US
Inventors: Pierre Lang
Original assignee: J Bobst et Fils SA
Current assignee: Bobst Mex SA
Priority date: 1967-12-11
Filing date: 1968-12-09
Publication date: 1971-05-04
Anticipated expiration: 1988-05-04
Also published as: FR1594630A; BE721653A; DE1800267A1; GB1229648A; CH466690A; CA923369A; SE338706B; JPS4940268B1; DE1800267C3

Abstract

A device for accurately centering the gripper bars carried by a pair of endless chains, in a desired working position in a press. Gripper bars are rigidly secured at their opposite ends to the endless chains during movement of the chains and when chain movement stops, the gripper bars are released from the chains for limited freedom of movement and means then cooperate with the freed gripper bars to positively accurately center the bars.

Description

United States Patent Inventor Pierre Lang Vaud, Switzerland Appl. No. 782,191 Filed Dec. 9, 1968 Patented May 4, 1971 Assignee J. Bobst 8: Fils S. A.

' Lausanne, Switzerland Priority Dec. 11, 1967 I Switzerland GRIPPER BAR MOUNT FOR PLATEN PRESS 14 Claims, 7 Drawing Figs. US. (l 93/58.3, 93/1, 198/19,198/180 lnt. CL B3lb l/20, B31b 17/02,B65g 17/14 Fieldofs'earch 93/1 (G), 58.3; 198/19, 180

[56] References Cited UNITED STATES PATENTS Re25,886 10/ 1965 Cargill 198/ 1 9X 2,425,039 8/ 1 947 Luehrs 93/1 2,949,066 8/ 1 960 Labombard 93/58.=3 2,974,572 3/1961 Shields 93/ 58.3 2,995,233 8/1961 Peras 198/19 FOREIGN PATENTS 1,234,088 10/1960 France 93/58.3

Primary ExaminerWayne A. Morse, Jr. Attomey-l-lill, Sherman, Meroni, Gross & Simpson ABSTRACT: A device for accurately centering the gripper bars carried by a pair of endless chains, in a desired working 1 position in a press. Gripper bars are rigidly secured at their op-' posite ends to the endless chains during movement of the chains and when chain movement stops, the gripper bars are released from the chains for limited freedom of movement and means then cooperate with the freed gripper bars to positively accurately center the bars.

Patented May 4, 1971 3 Sheets-Sheet l ATTORNEYS Patented May 4, 1971 3 Sheets-Sheet 2 INVENTOR.

Patented Ma 4,1971 3,577,834

3 Sheets-Sheet 5 INVENTOR.

GRIPPER BAR MOUNT FOR PLATEN PRESS BACKGROUND OF THE INVENTION Large-scale presses are now employed in the paper and cardboard industry which are designed for the purpose of handling multiple sheet stock. In addition to printing type presses such presses may for instance comprise machines known in the industry as die-cutters and creasers. The illustrated embodiment of the instant invention relates specifically to such die-cutter equipment although the invention will be found to have widespread utility.

In general, a die-cutting and creasing press may include a stationary upper platen and a relatively movable lower platen (or vice versa) which constitute the mating parts of the press. One or more of the platens carries tools on its working face (such as slitter blades, creasing rules and the like) so that by bringing the platens into contact with one another under high pressures, 800 tons or more, for instance, with a sheet of paper, cardboard or fiberboard, for, instance, sandwiched therebetween, crease lines and cutouts in such sheet stock can be made at desired points.

In automatic presses of this type sheets may be fed between the platens, worked, and removed from the platen interface at speeds upwards of ,000 sheets per hour.

To provide for the speedy passage of sheets through such presses two sets of endlm chains are provided which are trained over drive and idler wheels and which chains carry a plurality of gripper bars extending laterally across the machine and connected at their outer ends to the chains. The bars carry gripper fingers or other sheet gripping means which "grip" a sheet so that as the chains move, the gripped sheet is pulled through the machine to the working station. The chains then stop so that a sheet is approximately registered in its proper position at the platen interface and the platens are closed together to perform the die-cutting and creasing operation. Assuring that the sheet will be positioned in its exact registry position before the platens close together has been difficult in the past and it is the purpose of this invention to provide for just such exact registry in a simple and expeditious manner.

It is therefore an important object of this invention to provide an improved means for accurately registering an intermittently movable chain-carried gripper bar in a sheet fed press.

It is a more specific object of this invention to provide an as sembly wherein the gripper bars in a sheet fed press are rigidly afiixed to the conveying chains during movement of the chains and in which the bars are released for limited freedom of movement from the chains when the chains are stopped and wherein means are then provided for registering the gripper bars independently of the chains.

These and other objects, features and advantages of the present invention will become apparent from time to time as the following specification proceeds and with reference to the following drawings wherein:

FIG. 1 is a diagrammatic view of a platen press showing an endless chain trained over a pair of wheels and showing the working part of the press schematically in cross section;

FIG. 2 is a plan view of an end of a gripper bar showing with two opposed arrows the connection point between the gripper bar assembly and the endless chain;

FIG. 3 is an enlarged, fragmentary, horizontally sectioned view of the gripper bar assembly at the chain connection point;

FIG. 4 is a vertical sectional view taken along the line IV-IV of FIG. 2 and through the gripper bar assembly at the chain connection point showing the relative disposition of parts when the gripper bar is rigidly afiixed to the chain during chain travel;

FIG. 5 is a fragmentary vertical sectional view much like that of FIG. 4 but showing the relative disposition of parts when the gripper bar assembly is released from the chain for limited freedom of movement as when the chain has stopped press;

FIG. 6 is a front elevational view of the centering mechanism for the gripper bar assembly; and

FIG. 7 is a side elevational view of that centering mechanism showing some parts in elevation and others in vertical section.

FIG. 1 illustrates diagrammatically the design of a wellknown form of platen press such as is used for die-cutting and creasing operations. It comprises generally a main frame I having a heavy fixed upper platen 2 secured thereto and a pair of drive sprockets of wheels 3 and 4 rotatably mounted thereon.

A conveyor, here illustrated as comprising on endless chain 5 is trained over the wheels 3 and 4 and is intermittently driven in the direction of the arrow by the drive sprocket 3. One such wheel and chain combination is located on each side of the machine.

A plurality of gripper bar assemblies 6, 7, 8, 9, and 10 are provided to carry sheets through the press and these gripper bars are connected at their ends in equally spaced'relation to the chains on opposite sides of the press.

A heavy movable lower platen 11 is mounted on the frame and is adapted to move toward and away from the working lower face of the upper platen 2. The mating faces of the two platens carry complementary working tools, (such as slitter blades, creasing rules or the like), so that when the platens engage one another with a paper sheet sandwiched therebetween the desired cutting or creasing action will take place on the sheet.

The gripper bar assemblies each include a plurality of gripper bar fingers such as the fingers 12 illustrated in FIG. 2 and these fingers open and close (somewhat like clothespins) to grip the sheet S.

The chains 5 are successively set in motion and stopped when the platens are separated so that after each press operation a new sheet is carried by the gripper bar assemblies and chains into position between the platens. With the chains stopped and a sheet lying between the platens, the platens are brought together to apply pressure to the sheet and this process may be performed at a rate of 5,000 times per hour or more. Each sheet is held in this so called working position by the gripper bar assembly at location 7 and in this position the sheet and hence the bar at 7,should be accurately positioned or registered."

It is the purpose of this invention to provide for the exact registration of the gripper bars at the working station in the direction of their displacement (laterally in relation to the bar and longitudinally in the direction of the press), and hence for the exact registration of the sheet carried by the bars in a simple, accurate and expeditious manner. Gripper bar centering in the longitudinal sense (lateral in relation to the press) is carried out in the usual way and consists in guide rails in the press for guiding, in the present case, the carrier assemblies from one end of the press to the other.

FIGS. 2 through 5 illustrate the connection between the chains and the gripper bar assemblies. A gripper bar carrier 13 has an enlarged open end 14 within which is fitted the outer end 15 of gripper bar 7. A pair of chain pins 16 and 17 are mounted on the carrier and each of these pins serves as a means of connecting the carrier 13 into one of the endless chains 5 so that the carrier becomes a fixed part of the chain. The arrows in FIG. 2 illustrate diagrammatically this connection with the chain. A cover plate 18 is secured to the carrier body by screws 18a. The carrier body 13 has a circular opening 19 formed therein.

A pair of

openings

20 and 21 are formed within the carrier 13 on opposite sides thereof and these openings receive, without clearance at theirsides, the two opposed,

tenons

22 and 23, respectively, of the gripper bar 7. The

openings

20 and 21 are enlarged in a vertical direction somewhat more than the vertical height of the tenons to permit limited vertical movement of the tenons within the openings. The end 15 of the gripper bar 7 which is fitted within the carrier is narrower than the distance between the opposed inner sidewalls 14 of the carrier so that a clearance 24 is provided between the inner carrier walls and the gripper bar.

As a result, all axial movement of the bar 7 is opposed but av small degree of lateral movement in the direction of sheet conveyance is permitted.

In order to ensure that the gripper bar will be locked in a fixed position relative to the chain during movement of the chain, a locking piston 25 is provided. The piston 25 has an enlarged base 26, a truncated shoulder 27, and a cylindrical upper portion 28 terminating in an end face 29. The piston base 26 is slidably guided for rectilinear movement within a well 30 formed in the base wall of the cover 18. An opening 31 is formed within the end of the gripper bar 7 and this opening is defined by a chamfered edge 32 which is complementary with the truncated portion 27 of the piston 25. The cylindrical portion 28 of the piston is snugly fitted within the opening 19 so that upward movement of the piston (guided within well 30 and opening 19) will act through cooperation of the truncated section 27 of the piston and the complementary bevel 32 to center the bar end 15 in the carrier 13 and positively fix the two in relation to one another. In fact, a spring which may comprise a plurality of Belleville washers 33, is provided within the hollow interior of the piston and between the end face 29 and the base of the cover l8 to urge the piston to the extended position shown in FIG. 4. A centering post 34 is provided to center the washers and tenninates at a point sufficient to permit the piston to move to the position illustrated in FIG. 5.

In order to free the bar relative to the carrier 13 it is only necessary to press downwardly on the end face 23 of the piston against the opposing bias of the Belleville washers to seat the piston within the well and separate the

complementary surfaces

27 and 32. At such time the piston occupies the position illustrated in FIG. 5 and the gripper bar is free to move laterally within the carrier to the extent of the clearance 24 while axial gripper bar movement is prevented by reason of the close fit of the tenons in the sides of the

openings

20 and 21. This freed" position of the gripper bar in the carrier occurs at the time that exact registration of the bar takes place.

Gripper bar centering is achieved by means of assemblies best viewed in FIGS. 6 and 7.

A block 35 is secured to one side of the movable lower platen 11 and this block carries a pair of running

rollers

36, 37 mounted on pins 36a, 37a. The block 35 thus rises and falls with the lower platen 11 and occupies the upper position illustrated in FIG. 7 only when the chain has come to a rest and pressure is to be applied to the sheet by the platens. In FIG. 7 may be seen the working tools comprising a chase 38 carrying a plurality of knives or rules 39 and a counter plate 40 against which the blades or rules work. Rollers 38a facilitate withdrawal of the chase 38 from the press. The

rollers

36, 37 protrude slightly above the upper plane of the block 35 and are so positioned as to engage the under surface of the end of the gripper bar 7, when the bar has been freed from the carrier assembly as will hereafter be explained. The upper surface of the block 35 is adapted to engage the under surface of the cover plate 18 as the lower platen (and hence the block 35) moves upwardly.

A stem 41, carried by a supporting frame 42, has its lowermost end position in the path of movement of the piston 25. A spring which may comprise a series of Belleville washers 43, acts downwardly on the stem 41 and has a greater spring bias than the washers 33 so that when the carrier assembly begins to move upwardly, the lower end face of the stem 41 engages the piston 25 to provide the downward force on the piston necessary to free" the gripper bar from the carrier 13 (such freed position being shown in FIG. 5). 7

FIG. 6 illustrates the disposition of various parts of the assembly just at the moment of contact of stem 41 with the upper end face 29 of piston 25. At such time it will be noted that the block 35 supports the under surface of the cover plate 18 and that the clearance at point 36b between the

rollers

36, 37 and the bar 7 is about one-half that of the clearance 7a between the bar 7 and the cover plate 18. As a consequence, depression of the plunger 25 permits the bar 7 to fall within the carrier assembly until the bar comes to rest on the

rollers

36, 37.

The gripper bar 7 is thus freed from the carrier for limited lateral displacement and the ends of the gripper bar rest on the rollers such as 36, 37 so that the final centering or registration step can take place. Final registration is accomplished by means of a second stem 44 supported for limited vertical movement in the frame 42 and biased downwardly by a spring 45 or a series of Belleville washers.

The lowermost end of the stem 44 is provided with an elongated V-shaped groove which is complementary with a fitting 46 having a roofiike configuration and secured to the gripper bar 7 as shown in the other FIGS. The fitting 46 is screwed to the bar by means of the screw 46a and means (not shown) are provided for the purpose of ensuring that the planes of the complementary beveled surfaces of the stem 44 and fitting 46 are always normal to the major axis of the machine.

As the bar 7 moves upwardly, it is first freed for limited movement from the carrier 13 and is the centered accurately forwardly or rearwardly of the rest position of the carrier through the means of the V-notched stem and the complementarily ridged fitting 46. Stem 41 causes bar release and stem 44, bar centering.

Exact registration of the gripper bar at the working station is thereby attained while at the same time means have been provided to assure that the gripper bar will be fixedly carried by the chain during that interval when the chain is moving.

Lastly, it should be understood that while the invention will probably presently find its principle utility in connection with chain driven units, other conveyor means than chains might well be employed with equal facility such for example as endless belts, cables, or the like.

I claim:

1. In a press wherein sheets are carried to a working station by a conveyor driven gripper bar the improvement which comprises:

a carrier fixedly coupled to the conveyor,

a gripper bar, coupling means connecting said gripper bar to said carrier, said coupling means allowing free motion between said gripper bar and said carrier so that said gripper bar is never independent of the chain and stops when the chain stops, centering means registering said gripper bar within said carrier when said gripper bar is released from said carrier.

2. In a press including intermittently moving chains and a gripper bar for carrying stock to a working station within said press, the improvement comprising:

a carrier assembly integrally connected into a portion of said chain,

a gripper bar movably mounted on said carrier assembly,

centering means urging said gripper bar to a predetermined centered position within said press in one position of said chain, and

means fixedly mounting said gripper bar within said carrier assembly in another position of said chain.

3. The device recited in claim 2 wherein said gripper bar is permitted freedom of movement with respect to said carrier assembly only in a direction transverse to the longitudinal axis of said gripper bar.

4. The device recited in claim 2 wherein said centering means urges said gripper bar to a predetermined centered position within said press when said chains have stopped and wherein means fixedly mount said gripper bar in said carrier when said chains are moving and release said gripper bar for limited freedom of movement in said carrier assembly when said chains are stopped.

5. The device recited in claim 2 wherein said centering means urges said gripper bar to a predetermined centered position within said press when said chains have stopped and wherein means fixedly mount said gripper bar in said carrier when said chains are moving and release said gripper bar for limited freedom of movement in said carrier assembly when said chains are stopped and wherein said gripper bar is permitted freedom of movement with respect to said carrier assembly only in a direction transverse to the longitudinal axis of said gripper bar.

6. in a platen press including a pair of mating platens, a pair of endless intermittently moving chains on opposite sides of the press and at least one gripper bar connected at its ends to said chains for carrying stock to a working station within the press, and wherein the chains are brought to rest each time a gripper bar advances t a working station, the improvement which comprises:

a carrier assembly fixedly connected to each said chain, and

receiving an end of said gripper bar,

interengagement means on the ends of each said gripper bar and said carrier assembly cooperating to prevent movement of said gripper bar along its axis relative to said carrier assemblies,

said gripper bar having limited freedom of lateral movement within said carrier assemblies,

a vertically movable at least partially conically configurated piston mounted on said carrier and extending through an opening in said gripper bar,

whereby movement of said piston in one direction will engage the conical portion of said piston with the portion of said gripper bar defining said opening, to lock; said gripper bar and said carrier assembly together 'and whereby movement of said piston in an opposite direction will disengage said piston and gripper bar to free said bar,

a centering fitting extending outwardly from said gripper bar,

means raising and lowering said gripper bar simultaneously with closing and opening movement respectively of said platens,

abutment means disposed in the path of said piston during closing movement of said platens to engage and move said piston to free said gripper bar for limited freedom of movement within said carrier assembly, and

a centering abutment having an inverted tapered surface engageable with said centering fitting during closing movement of said platens as said gripper bar is freed for limited movement from said carrier assembly.

7. The structure of claim 6 wherein said centering fitting has a roof-shaped profile with the roof ridge parallel to the axis of said gripper bar and said centering abutment has an inverted roof-shaped profile likewise oriented.

8. The structure of claim 6 wherein spring means bias said piston in one direction and wherein piston engagement with said abutment means moves the piston in an opposite direction and wherein said abutment means and said centering abutment are resiliently supported on said press.

9. In a platen press including sets of gripper bars for conveying sheets to a working station wherein the bars are connected at their ends to a pair of intermittently movable chains, the improvement which comprises:

carrier means connecting the bar ends to the chain and providing play in the conveying direction,

means interconnecting the carrier means and the bar rigidly during chain conveyance,

means releasing said bar from said carrier means to accommodate said play when said chains have stopped,

and means including a cooperating centering element on the frame of said press and on said gripper bar for centering said gripper bar when said bar release takes place.

10. A press according to claim 9, in which each bar end is engaged with lateral play but without axial play into a carrier assembly box integral with the corresponding chain.

11. A press according to claim 10, in which a member extends through the bar and atleast a wall of the box perpendicularly to the working plan, which member protrudes from the box under the action of springs and locks the bar in fixed position through the cooperation of a frustum on the member and a cooperating seat of same profile on the bar, whereby pushing back the said member against the opposing action of the springs will restore the free play of the bar.

12. A platen press according to claim 6 wherein the means raising and lowering said gripper bar comprise a block engageable with said carrier assembly and rollers mounted with said block on a moving platen, which said rollers are engageable with the said gripper bar in the freed position of said bar so as to facilitate displacement of the bar in the sense of its lateral play.

13. A platen press according to claim 9 wherein the means raising and lowering said gripper bar comprise a block engageable with said carrier assembly and rollers mounted with said block on a moving platen, which said rollers are engageable with the said gripper bar in the freed position of said bar so as to facilitate displacement of the bar in the sense of its lateral play.

14. The platen press of claim 6 wherein said interengagement means comprise tenons extending horizontally outwardly from a perpendicular to the longitudinal axis of said gripper bar and vertically enlarged slots formed in said carrier assembly and snugly receiving the tenons along the side edges of the slots.

Claims

1. In a press wherein sheets are carried to a working station by a conveyor driven gripper bar the improvement which comprises: a carrier fixedly coupled to the conveyor, a gripper bar, coupling means connecting said gripper bar to said carrier, said coupling means allowing free motion between said gripper bar and said carrier so that said gripper bar is never independent of the chain and stops when the chain stops, centering means registering said gripper bar within said carrier when said gripper bar is released from said carrier.

2. In a press including intermittently moving chains and a gripper bar for carrying stock to a working station within said press, the improvement comprising: a carrier assembly integrally connected into a portion of said chain, a gripper bar movably mounted on said carrier assembly, centering means urging said gripper bar to a predetermined centered position within said press in one position of said chain, and means fixedly mounting said gripper bar within said carrier assembly in another position of said chain.

6. In a platen press including a pair of mating platens, a pair of endless intermittently moving chains on opposite sides of the press and at least one gripper bar connected at its ends to said chains for carrying stock to a working station within the press, and wherein the chains are brought to rest each time a gripper bar advances to a working station, the improvement which comprises: a carrier assembly fixedly connected to each said chain, and receiving an end of said gripper bar, interengagement means on the ends of each said gripper bar and said carrier assembly cooperating to prevent movement of said gripper bar along its axis relative to said carrier assemblies, said gripper bar having limited freedom of lateral movement within said carrier assemblies, a vertically movable at least partially conically configurated piston mounted on said carrier and extending through an opening in said gripper bar, whereby movement of said piston in one direction will engage the conical portion of said piston with the portion of said gripper bar defining said opening, to lock said gripper bar and said carrier assembly together and whereby movement of said piston in an opposite direction will disengage said piston and gripper bar to free said bar, a centering fitting extending outwardly from said gripper bar, means raising and lowering said gripper bar simultaneously with closing and opening movement respectively of said platens, abutment means disposed in the path of said piston during closing movement of said platens to engage and move said piston to free said gripper bar for limited freedom of movement within said carrier assembly, and a centering abutment having an inverted tapered surface engageable with said centering fitting during closing movement of said platens as said gripper bar is freed for limited movement from said carrier assembly.

9. In a platen press including sets of gripper bars for conveying sheets to a working station wherein the bars are connected at their ends to a pair of intermittently movable chains, the improvement which comprises: carrier means connecting the bar ends to the chain and providing play in the conveying direction, means interconnecting the carrier means and the bar rigidly during chain conveyance, means releasing said bar from said carrier means to accommodate said play when said chains have stopped, and means including a cooperating centering element on the frame of said press and on said gripper bar for centering said gripper bar when said bar release takes place.

11. A press according to claim 10, in which a member extends through the bar and at least a wall of the box perpendicularly to the working plan, which member protrudes from the box under the action of springs and locks the bar in fixed position through the cooperation of a frustum on the member and a cooperating seat of same profile on the bar, whereby pushing back the said member against the opposing action of the springs will restore the free play of the bar.