US3563166A - Rotary press - Google Patents

Abstract

A rotary press for smoothing or embossing leather and like flat objects has a rotating pressure cylinder which cooperates with a concavely cylindrical trough on a stationary anvil. The object to be pressed passes through the trough between the cylinder and a laminar belt arrangement moving at the circumferential speed of the roller. The belt arrangement includes an abrasion resisting metal drive belt slidingly engaging the anvil, and a supporting belt of resilient material interposed between the drive belt and the pressed object.

Description

United States Patent lnventors Appl. No. 747,162 Filed July 24, 1968 Patented Feb. 16, 1971 Assignee Strojosvit narodni podnik Krnov, Czechoslovakia Priority Aug. 7, 1967 Czechoslovakia 5,679/67 ROTARY PRESS 4 Claims, 2 Drawing Figs.

U.S. Cl. 100/ 153, 100/156 Int. Cl. 83% 3/00, B30b 5/04 Field ofSeareh 100/151. 152, 154, 168, 172, 176,210; 69/48; 101/3; 18/10; 100/153, 156

Karel Bajak; I Vaclav Oplustil, Krnov, Cuchoslovakia [56] References Cited UNITED STATES PATENTS 838,615 '12/1906 Goldman l. 100/153X 1.176.609 3/1916 Scott 100/156 Primary E.raminer Edward L. Roberts Attorney-Richard Low ABSTRACT: A rotary press for smoothing or embossing leather and like flat objects has a rotating pressure cylinder which cooperates with a concavely cylindrical trough on a stationary anvil. The object to be pressed passes through the trough between the cylinder and a laminar belt arrangement moving at the circumferential speed of the roller. The belt arrangement includes an abrasion resisting metal drive belt slidingly engaging the anvil. and a supporting belt of resilient material interposed between the drive: belt and the pressed object.

ROTARY PRESS BACKGROUND OF THE INVENTION This invention relates to the finishing of leather and particularly to a rotary press for unfinished leather and'like flat objects.

In the finishing of leather,.the' unfinished material is compressed to improve its mechanical properties, to change its dimensions, and to give it a desired surface finish. Both smooth and textured surface configurations are produced by high pressure with or without simultaneous heating.

The machinery available heretofore is of two general types. In one type, leather is pressed between two hydraulically operated platens. This arrangement permits any desired dwell time in the pressure zone to be chosen. However, it can be used only in a batch operation and has all the known economical disadvantages of such operation. It is not possible to treat large pieces of unfinished leather in a single pressing step because of practical limitations of the available hydraulic equipment and the corresponding limitations on platen size. When complex patterns are to be embossed on the leather, it is almost impossible to obtain proper registration between the several separately embossed portions of the pattern;

The second type of known machinery is equipped with pairs of pressure cylinders forming a nip for continuous passage of the flat object to be pressed. The operation is continuous, but

the dwell time of the object in the nip is so short if a reasonable production rate is to be achieved that the patterning possi- T bilities of the device are extremely limited.

The object of the invention is the provision of equipment for pressing leather and similar flat objects which combines the. aforedescribed advantages of the two types of known presses,

yet is free of their shortcomings.

SUMMARY OF THE INVENTION The invention provides a single pressure cylinder mounted on a support for rotation about its axis. The cylinder cooperates with an anvil fixedly mounted on the support and defining a trough of arcuate cross section transversely of the cylinder axis. A belt arrangement is mounted on the same support for translatory movement over the anvil in sliding engagement with the trough. The machine drive rotates the cylinder about its axis and simultaneously moves the belt arrangement over the anvil at a speed substantially equal to the circumferential speed of the cylinder while the cylinder is being urged under pressure toward the belt arrangement and the trough.

The belt arrangement may include a driving belt and a superimposed supporting belt, the former engaging the trough during belt movement and the latter facing the cylinder and defining with the same a gap of substantially uniform thickness in a radial direction relative to the cylinder axis when the cylinder is in its operative position in which its axis coincides with the axis of curvature of the trough.

The belts are preferably continuous and extend in loops.

Other features, additional objects, and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understood by reference to the following detailed description of a preferred embodiment when considered in connection with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1. shows a leather finishing press of the invention in side elevation; and

FIG. 2 shows working elements of the press of FIG. 1 on a larger scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing in detail, and initially to FIG. I, there is seen a rotary press of the invention which has certain features in common with a rolling mill of the type used in steel mills.

The press shown has a heavy frame 1 whose upright sidewalls 2 are apertured. The two sidewalls 2 are connected by a heavy cross member or anvil 3 shaped to resist bending under vertically applied stresses. The top of the anvil 3 forms an upwardly open trough which is cylindrically curved in part. Two cylindrical rolls 4, 4 are mounted on the front and rear of the frame 1 between the side walls 2.

A flexible endless steel drive belt 5 is trained in a closed loop over the rolls, 4,4 and the trough of the anvil 3, and is kept under sufficient tension for driving engagement with the roll 4, the roll 4' being an idler and mounted in bearings which may be adjusted toward and away from the roll 4 in a forward and backward direction in a manner not shown in the drawings. Guide rollers 6,6 are rotatably attached to the frame 1 in a nonillustrated manner in front of the roll 4 and behind the roll {to guide a supporting rubber belt 7 in a loop over the rolls 4,4 and through the trough of the anvil 3 on top of the steel belt 5.

A bearing block 8 is vertically guided in the aperture of each sidewall 2 to support a pressure cylinder 9 above the trough in the anvil 3. Each bearing block 8 is secured to the transverse top member 12 of the frame 1 by a hydraulic cylinder 10 which encloses a piston, not itself visible in the drawings. A piston rod 10 projects axially from both ends of the cylinder 10. The downward stroke of the piston rod 10 on which the block 8 is fastened is limited by adjustable nuts 11 on the threaded end portion of the rod which projects upward from the transverse frame member 12.

A variable speed motor 13 drives the roll 4 by means of a chain 14, and drives the cylinder 9 by means of a sprocket 17 on a countershaft and connecting chains 15, 16. The transmission ratio of the several chain drives is chosen in such a manner that the circumferential speed of the cylinder 9 is equal to the translatory speed of the drive belt 5.

As is better seen in FIG. 2, the cylindrically curved portion 19 of the trough in the anvil 3 is centered approximately in the axis of rotation of the cylinder 9 when a piece 18 of unfinished leather passes the gap between the supporting belt 7 and the cylinder 9 above the trough portion 19 of the anvil 3. The leather, while traveling through the pressure zone is reduced in thickness.

The press may be operated by the motor 13 at a belt speed of one to thirty meters per minute,"and the dimensions of the press are such that the resulting dwell time of thetreated piece 18 in the high-pressure zone at 19 is 15 to 0.5 seconds. In an actual embodiment of the press, the hydraulic cylinders 10 produce in the zone a pressure which may be adjusted between 20 and kg per square centimeter (about 300 to 2,200 lbs./sq.in.). Moreover, the press is equipped with interchangeable cylinders 9 some of which have smooth surfaces whereas the working faces of others, not shown, are engraved to produce a desired grain pattern in the leather piece 18, and equipped with hollow trunnions for connection to a steam line in a manner well known in itself.

There is no relative movement between the surface of the cylinder 9,-the leather piece 18, and the belts 5,7 while the leather passes the pressure zone at 19. The resilient rubber belt 7 yields sufficiently to compensate for any variation in the thickness of the leather piece 18 and is protected against abrasion by frictional contact with the anvil 3 by the steel belt 5. The contact area of the latter with the anvil is much smaller than the contact area with the drive roll 4. It is therefore possible to provide a lubricant film at the interface of the anvil and of the belt 5 without significant loss of traction at the drive roll 4.

The illustrated press provides the dwell time in the highpressure zone which is necessary for producing'many grain patterns on leather. lt avoids relative movement of the leather and of the pattern forming die or cylinder 9 in the high-pressure zone, and therefore permits fine detail in the pattern to be faithfully reproduced. The leather is uniformly treated, and the pattern extends continuously over the entire leather surface.

This is achieved in continuous operation with a minimum of manual labor. The leather pieces are merely placed by an operator or by an automatic feeding conveyor, not shown, on the portion of the belt 7 at the rear end of the machine between the idler roll 4 and the associated guide roller 6, and the pressed or embossed leather piece is discharged over the front roller 6.

Similar advantages are achieved with the use of smooth-surfaced cylinders 9 which produce a corresponding uniform finish on pressed leather pieces. The fact that the leather is stressed exclusively at right angles to its surface while passing through the press illustrated is believed to account for the superior appearance and mechanical properties of the processed leather.

We claim:

1. A press for leather and like flat objects comprising, in combination:

a. a support;

b. a pressure cylinder having an axis and mounted on said support for rotation about said axis; c. anvil means fixedly mounted on said support and defining a trough of arcuate cross section transversely of said axis;

d. belt means mounted on said support for translatory movement over said anvil in sliding engagement with said trough;

e. pressure means for urging said cylinder under pressure toward said belt means and said trough; and

f. drive means for rotating said cylinder about said axis and for simultaneously moving said belt means over said anvil at a speed substantially equal to the circumferential speed of said cylinder.

2. A press for unfinished leather and like flat objects comprising, in combination:

a. a support;

b. a pressure cylinder having an axis and mounted on said support for rotation about said axis; c. anvil means fixedly mounted on said support and defining a trough of arcuate cross section transversely of said axis;-

d. belt means mounted on said support for translatory movement over said anvil in sliding engagement with said trough; said belt means including a belt member and a supporting belt member superimposed on said driving belt member, said driving member engaging said trough during the movement of said belt means, and said supporting belt member facing said cylinder;

e. pressure means for urging said cylinder under pressure toward said belt means and said trough; and

1. drive means for rotating said cylinder about said axis and for simultaneously moving said belt means over said anvil at a speed substantially equal to the circumferential speed of said cylinder.

3. A press as set forth in claim 2, said trough being of substantially cylindrically arcuate shape, said pressure means including means for moving said cylinder into a position in which the axis thereof substantially coincides with the axis of curvature of said trough, and said supporting belt member and said cylinder define therebetween a gap of substantially uniform thickness in a radial direction relative to said axis.

4. A press as set forth in claim 3, said belt members each extending in a continuous loop.

Claims (4)

1. A press for leather and like flat objects comprising, in combination: a. a support; b. a pressure cylinder having an axis and mounted on said support for rotation about said axis; c. anvil means fixedly mounted on said support and defining a trough of arcuate cross section transversely of said axis; d. belt means mounted on said support for translatory movement over said anvil in sliding engagement with said trough; e. pressure means for urging said cylinder under pressure toward said belt means and said trough; and f. drive means for rotating said cylinder about said axis and for simultaneously moving said belt means over said anvil at a speed substantially equal to the circumferential speed of said cylinder.

2. A press for unfinished leather and like flat objects comprising, in combination: a. a support; b. a pressure cylinder having an axis and mounted on said support for rotation about said axis; c. anvil means fixedly mounted on said support and defining a trough of arcuate cross section transversely of said axis; d. belt means mounted on said support for translatory movement over said anvil in sliding engagement with said trough; said belt means including a belt member and a supporting belt member superimposed on said driving belt member, said driving member engaging said trough during the movement of said belt means, and said supporting belt member facing said cylinder; e. pressure means for urging said cylinder under pressure toward said belt means and said trough; and f. drive means for rotating said cylinder about said axis and for simultaneously moving said belt means over said anvil at a speed substantially equal to the circumferential speed of said cylinder.

3. A press as set forth in claim 2, said trough being of substantially cylindrically arcuate shape, said pressure means including means for moving said cylinder into a position in which the axis thereof substantially coincides with the axis of curvature of said trough, and said supporting belt member and said cylinder define therebetween a gap of substantially uniform thickness in a radial direction relative To said axis.

4. A press as set forth in claim 3, said belt members each extending in a continuous loop.

Images