US2506845A

US2506845A - Plate cylinder for rotary printing presses

Info

Publication number: US2506845A
Application number: US61187A
Authority: US
Inventors: Solomon Randolph
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-11-20
Filing date: 1948-11-20
Publication date: 1950-05-09
Anticipated expiration: 1967-05-09

Description

May 9, 1950 R. SOLO ON PLATE CYLINDER FOR ROTARY PRINTING PRESSES Filed Nov. 20, 1948 2 Sheets-Sheet 1 Vu|l:

INVENTOR.

. R W LPH L M N A770 RNEYS May 9, 1950 R. SOLOMON PLATE CYLINDER FOR ROTARY PRINTING PRESSES' Filed Nov. 20, 1948 2 Sheets-Sheet 2 INVENTOR. RANDOLPH L M N 02....4 M MM ATTORNEYS Patented May 9, 1950 UNITED STATES PLATE CYLINDER FOR ROTARY PRINTING PRESSES Randolph Solomon, Washington, D. C., assignor of one-half to Edward Stewart, Washington,

Application November 20, 1948, Serial No. 61,187

4 Claims.

This invention relates to plate cylinders used in rotary printing presses and more particularly to the means for clamping and retaining stereotype plates on such cylinders by exerting a circumferential tension on the plates. 1 lore specifically, it relates to that type of plate cylinder wherein the plate clamping and retaining means comprises a gripper unit removably mounted in a longitudinal recess in the cylinder surface and to means for maintaining this unit in place in the recess.

Heretofore, means have been proposed for clamping and retaining stereotype plates on a printing-press-plate cylinder by exerting circumferential tension on the plates, but certain objectionable features to the use of plate cylinders so equipped are introduced when the gripper members of the unit become worn and require replacement. Such replacement of the gripper members requires the removal of a substantial amount of the machinery at the sides of the press. With the type of gripper units currently used the removal operation, indicated as being necessary for replacement of grippers, is a time consuming and therefore expensive operation. Additionally, it may result in a considerable period of idleness for the whole printing press.

Broadly, the present invention contemplates a structurally simple and easily applicable means for retaining and looking a gripper unit within its receiving recess in a plate cylinder and for quickly releasing it from such recess when replacement of gripper members is desirable. Such retaining and locking means is so designed and fitted in the plate cylinder that no part or parts of it need be removed from the plate cylinder to release the gripper unit and thereby possible loss or damage of the parts incident to removal is obviated, and complete simplicity of the mount ing of the unit in the cylinder recess and the removal of it therefrom are achieved.

More specifically, the present invention contemplates the use of rotary cam-locking shafts rotatably mounted in holes extending through the plate cylinder contiguous and in communication with the cylinder recess. Each of the cam shafts has a portion of its surface flattened throughout its length so that when rotated to a certain position within its receiving hole in the plate cylinder it lies wholly within the hole and when rotated to a different position within the hole a portion of it protrudes into the cylinder recess. Arcuate grooves are so formed longitudinally in the side walls of the gripper unit that when the unit is in place within the plate cylinder recess these grooves lie opposite the shaft-receiving holes of the cylinder. The radii of the arcuate grooves are the same as those of the cam shaft holes so that when the unit is in place the cam shaft holes are in fact completed.

For insertion or removal of the unit, the cam shafts must be turned to the position at which they lie wholly within their cylinder holes. When the unit has been placed in the recess, the cam shafts need merely be rotated and the unit will be securely locked in place, a portion of the shafts protruding into the arcuate grooves of the gripper unit. Means are also provided for preventing rotation of the cam-locking shafts after they have been rotated to locking position so that they may not work around to their gripper-unitreleasing position during subsequent use of the plate cylinder.

The invention will be further described in connection with the accompanying drawings in which:

Fig. 1 is a plan view of a gripper unit mounted in a recess of a plate cylinder,

Fig. 2 is a view of one end of a plate cylinder having gripper units mounted therein and provided with stereotype plates, showing more clearly the means for rotating the shafts of the gripper units upon which are mounted the grippers,

Fig. 3 is a transverse sectional view taken on line 3-3 of Fig. l, the cylinder here shown, however, being provided with stereotype plates,

Fig. 4 is a partial sectional view taken along line 4-4 of Fig. 3,

Fig. 5 is a partial sectional view taken along line 55 of Fig. 2, showing more clearly the flanged end of a rotatable cam-locking shaft,

Fig. 6 is a partial sectional view showing an end securing member at the opposite end of the rotatable cam-locking shaft shown in Fig. 5, and

Fig. '7 is a fragmentary perspective view of a gripper-unit-rotatable cam-locking shaft.

Referring to the drawings, a rotary printingpress-plate cylinder I0, having wear-receiving liners l0 removably secured thereto, is provided with recesses ll extending longitudinally throughout its length and shaped so as to receive gripper units If by which stereotype plates I3 are held in place on the plate cylinder. While a plate cylinder is normally provided with two gripper units, each of these is identical in structure and operability to the other and therefore but one will be described. The gripper unit comprises a base portion I4, end walls l6 and ribbed sections [1 projecting from the base portion at spaced intervals between the end walls. Grippers I8 and I9 are adapted to be mounted opposite one another, in the spaces between the ribbed sections, on shafts 2| and 22, respectively. These shafts are freely rotatable within

holes

23 and 24 which pass entirely through the end walls and ribbed sections of the gripper unit. The. grippers are so mounted on the shafts as by keys 25 that they rotate with the shafts.

Dogs

26 and 21 are keyed to the ends of the shafts 2| and 22, respectively, which protrude from the ends of the gripper unit and extend beyond the corresponding ends of the plate cylinder. Set

screws

29 and 3|] are threadedly held in the ends of the dogs remote from the shafts and are adapted to have their distal ends abut shoulders 3| of the plate cylinder shaft when the gripper unit is in position within one longitudinal recess H. By taking up on the set screws, the ends of the dogs are forced outwardly from the plate-cylinder shaft, consequently turning their respective gripper unit shafts in opposite directions and causing the plate-engaging tips of the oppositely faced grippers to come closer together and to exert a greater circumferential tensile strain on the printing plates.

Holes

33 and 34 are provided in the plate cylinder contiguous and in communication with the gripper unit recess and extend throughout the length of the cylinder. Complimentary

arcuate grooves

35 and 36 are provided in the opposite sides of the base portion 14 of the gripper unit and have the same radii as do

holes

33 and 34 in the plate cylinder, and are so located in the opposite sides of the gripper unit that when the gripper unit is placed in the cylinder recess they are respectively opposite

holes

33 and 34.

Rotatable cam shafts

39 and 40 are provided, each havin one end flanged as at 4! and 42 (shown in Fig. respectively, and fit into

holes

33 and 34 of the plate cylinder. Each cam shaft has a flat surface portion 43 extending throughout its length so that when it is turned to a predetermined position it will lie wholly within its receiving hole in the plate cylinder. The ends of the cam shafts remote from the flanged ends threadably, or in any other suitable manner, receive securing members 44 and 45 as shown in Fig. 6. The cam shafts when once inserted in the plate cylinder and securably held therein, by their flanged ends and the application of securing members 44 and 45 need not be removed. Polygonal kerfs 4B, of the type which are adapted to receive Allen wrenches, are provided in the flanged ends of the cam shafts and in the securing members for tuning them when it is desired to insert the gripper unit into the cylinder recess or to remove it therefrom.

To insert the gripper unit into a cylinder, the cam shafts are first turned until they lie wholly within

holes

33 and 34. The gripper unit is then placed in the cylinder recess and the rotatable cam shafts are rotated, causing an arcuate portion of each to be received by the complimentary

arcuate grooves

35 and 36. This locks the unit in the cylinder and prevents its removal. To release the unit the reverse procedure is followed. The flanged ends of the cam shafts and the securing members 44 and 45, in addition to providing means for maintaining such shafts within the cylinder, prevent longitudinal movement of the gripper unit in the cylinder because of the fact that they overlap the ends of the arcuate grooves.

Locking screws 49 are provided in order to prevent the cam shafts from accidently turning during the use of the printing press and thereby releasing the gripper unit. They are threadedly received in the cylinder ends adjacent the cam shaft holes. Grooves 5| are formed in the edges of the flanged ends of the cam shafts and in the heads of the securing members 44 and 45, and are so positioned therein as to receive the locking screw heads when the cam shafts are in position to maintain the gripper unit in place. The lock.

ing screws need not be removed entirely from the cylinder when it is desired to turn the cam shaft but only a sufficient distance to have their heads fully withdrawn from the grooves 5!. The locking screws also may be of the type that are operable by Allen wrenches so that if when placed in a printing press the plate cylinder has parts of the press adjacent its ends which narrowly confine the space available in which to work the gripper-unit-locking means may nevertheless be operated.

It should be clearly understood that varioul modifications may be made in the disclosed ap-\ paratus without departing from the invention or sacrificing the advantages thereof, and the scope of the invention is limited only to the extent set forth in the appended claims.

I claim:

1. In a rotary printing-press-plate cylinder having a longitudinally-extending recess at the periphery thereof, a plate-gripper unit removably mounted in said recess, a shaft rotatably mounted in the gripper unit and extending longitudinally thereof, plate-gripping means non-rotatively mounted on and extending longitudinally of said shaft, means for selectively rotating said shaft in directions to move said gripping members transversely of the cylinder to plate-gripping and ungripping positions, at least one of the sides of the plate-gripper unit opposite the sides of the recess in the cylinder having a longitudinally-extending groove, the cylinder having a longitudinally-extending groove in the sidewall of the recess opposite the groove in the plategripper unit, an elongated rotatable cam-locking member in the groove of the cylinder, and means for selectively rotating said cam-locking member to positions in which a portion thereof extends into the groove in the plate-gripper unit and locks the plate-gripper unit in the recess in the cylinder and in which the cam-locking member lies wholly without said groove to permit removal of the plate-gripper unit.

2. The structure set forth in claim 1 which includes means threadably mounted in an end of the cylinder for preventing rotation of the elongated cam-locking member when the latter is in its locking position.

3. The structure of claim 1 in which the means for rotating the shaft having the plate-gripping members mounted thereon comprises a member fixedly mounted on one end portion of said shaft and a screw threadedly mounted in said member and having one end thereof engageable with a shoulder of the cylinder.

4. The structure of claim 1 in which each of said sides of the plate-gripper unit and the recess have the longitudinally-extending cooperating means for locking the plate-gripper unit in the cylinder recess.

RANDOLPH SOLOMON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 868,263 Goss Oct. 15, 1907 1,262,185 Drew Apr. 9, 1918 1,276,336 Drange Aug. 20, 1918 1,384,590 Bottone July 12, 1921 1,503,074 Swift July 29, 1924