US2248612A - Means for positioning and holding printing plates - Google Patents

Description

juiy 8, 1941..

C. S. CRAFTS MEANS FOR POSITIONING AND HOLDING PRINTING PLATES 2 Sheets-Sheet 1 Filed Oct. 20, 1938' ha I FIQEEEEEEEEEEEEEzEEE I ufiy 8, 3941- c. s. CRAFTS MEANS FOR POSITIONING. AND HOLDING PRINTING PLATES Filed Oct. 20, 1938, 2 Sheets-Sheet 2 XJNVENTOR f ATTORNEYS rrso STATES TENT crews MEANS FOR, POSITIONING AND HOLDING PRINTING PLATES Curtis S. Crafts, Oak Park, 111;, assignor to The Goss Printing Press Company, Chicago, Ill., a corporationof Illinois Application October 20, 1938, Serial No. 236,017

(01. lob-37 8 11 Claims.

The invention relates to new and useful improvements in positioning and clamping mechanisms for printing plates and in certain of its features the invention relates more particularly firmly supported underneath on thetrue surface of the cylinder right up to the bevel edge of the plate beneath the clamp; whereby the plate is precisely and firmly supported on the true surto such improvements in plate positioning and face of the cylinder at the very points where clamping means in rotary printing presses. the clamping pressure is applied. To this end Objects and advantages of the invention will there is provided a clamping member or platebe set forth in part hereinafter and in part will clip travelling in the clip-way having a jaw for be obvious herefrom, or may be learned by pracengaging the beveled plate edge, and a platetice with the invention, the same being realized 101 supporting member in the clip-way, movable with and attained by means of the instrumentalities the plate-clamping member, having its upper surand combinations pointed out in the appended face true with the cylinder surface and directly claims. supporting the plate right out to the beveled The invention consists in the novel parts, conedge where it is engaged by the clamp, this platestructions, arrangements, combinations and im supporting member itself being supported by the provements herein shown and described. cylinder to that same point. 1 g

The accompanying drawings, referred to here- It is customary to use plate-supporting or fillin and constituting a part hereof,illustrate eming-in pieces in the clip-ways beneath the plates bodiments of the invention, and together with toprevent the plates bending into the clip-ways the description, serve to explain the principles of under pressure, "and it is customary to grind the invention. these plate-supporting members with the cylin- Of the drawings: der, so as to obtain a fixed and true cylindrical Fig. 1 is a longitudinal fragmentary section surface for all of said members. The usual plate through a part of a printing cylinder and showc ips have 'a body part extending inwardly from ing a mechanism embodying the invention a-pthe jaw beneath the plate, and this extension plied to a printing plate on the cylinder; is the support for the plate over the clip-way Fig.2 is a transverse section on line 2-2 of and inwardly from the jaw. '11; is very dim- Fig. 1; cult in manufacture to grind these usual plate Fig. 3 is a transverse section on line 33 of clamps'or plate clips so that the top of the body Fig. 1; 1 1 of the clip beneath the 'plate is of true cylinder Fig. 4 is a transverse section on line 44 of height, andit is frequently too low. Even when Fig. 1; properly made, the clips wear and with the prior Fig. 5 is a transverse section on line 5-5 of art forms, soonbecome loose so that the plates Fig. l; i are not securely held. Consequently, when the Fig. 6 is a longitudinal transverse section on plate is locked up, the bevel on the plate tends line 6-6 of Fig. 5; to lift up theclip; The present invention pro- Fig. 7 is a transverse section on line 1-1 of vides plate-supporting and fastening means Fig. 1; wherein a plate-supporting or filling-in mem- Fig. 8 is a fragmentary plan of the central ber, which has beengroundwith the cylinder to portion of the cylinder and showing the central a true surface flush with thecylinder, has an plate support in the clip groove; extension which supports the plate practically Fig. 9 is a transverse section taken on the out to the'beveled edge and beneath the clampline 9-9 of Fig. 1; and ing jaw, participating in' the clamping action,

Fig. 10 is a transverse section on the line |0 l0 while the extension is itself supported throughof Fig. 1.

Objects of the invention are to provide an improved plate-supporting and clamping mechanism which will hold the plate firmly and accurately in position and '.will avoid movement of the plate at the clamped edges and also avoid bending or beating down the plate into the clipways; to provide novel mechanism operating at the bevel edge of the plate whereby the plate will be firmly clamped and at thesametime be out its length by the cylinder. The plate clip or cl-amp'is cut down or relieved at its inner part (any definite relation to the cylinder surface not being required), and this outward extension of the supporting member extends over the cutdown inner part of the clip with clearance.v The clip and this adjacent and cooperating plate member may both be threaded. on a single screw? rod s0 that after they are once relatively positioned they will travel together as the screwrod is turned to clamp and release the plates. With this construction the plate clip may be a fairly loose fit in the cylinder, as the clip in the preferred form does not support the plate but merely clamps it to the cylinder. The cooperating supporting member, which supports the plate right out to its beveled edge, can in manufacture be fastened in the clip-way during the grinding of the cylinder, and thus it will have a true surface always flush with the surface of the cylinder. By mounting the plate clip and this cooperating plate supporting member on the screw, they will be always moved and kept in the desired relative position together by turning the screw.

-It will be understood that the foregoing general description and the following detailed description as Well are exemplary and explanatory of the invention but are not restrictive thereof.

Referring now in detail to the embodiment of the invention illustrated by way of example in the accompanying drawings, it is shown applied to the plate cylinder of a rotary press which uses stereotype or electro'type plates which are of relatively thin section, the cylinder being of the usual form which takes four printing plates around and four plates along the cylinder. The plate-holding means comprises a plurality of channels or clip-ways I, which are cut into the plate cylinder 2 longitudinally of, that is, along the elements of the cylinder. These channels or clip-ways extend from either end of the cylinder to approximately the middle thereof, be-

neath two plates, and each holding the positioning, clamping and supporting devices for the two plates. There is usually provided in fixed position centrally of the length of the cylinder an annular, doubly beveled clamping ring 3 which takes the inside beveled edges of the two ,1 inside plates and positions and holds them. The 4 remaining clamps for the printing plates 79 and p at either side are longitudinally movable in the clip-way to fasten and unfasten the plates, all in a well-known manner. As embodied, the side walls of the clip-way l and also those of the clamps and plate-supporting members are mutually shaped cross-sectionally so that the clamps and supporting pieces are slidably supported in the clip-way between the guideways 6 and 8 and I and 9. As here embodied, a pair of inwardly-projecting supports and guides B and I extend along the sides of the clip-way l, and an additional pair of inwardly-projecting supports 8 and 9 are arranged near the bottom part of the clip-way, the bottom part of the clip-way being open beneath the clamping and supportingmembers to provide against obstructive ma-- terial' lodging in the path of movement of the plate clips and plate supports.

Supporting members beneath the central part of the plate may be of any desired form in so far as concerns the main features of the present invention. As shown in Fig. l, a stationary plate support [2 is located in a central rectangular part of the clip-way and rests upon supporting projections 8 and 9 and is held in position by countersunk screws l5 passing downwardly through the block l2 and screw-threaded into the cylinder 2. Another form of plate-supporting device which is also removable from the clipway is shown in Figs. 1 and 5, wherein a slidable supporting block 18 is supported on the projections 6 and 7, and extends downwardly into the straight wall part of the clip-way formed by the faces of these projections. A block or plate i9,

formed as a paralellogram, is located in the lower part of the clip-way, and is sufficiently long so that its upper face abuts on the bottom faces of the guideways 3 and T when the plate is turned crossways of the guideways. A countersunk screw 20 projects downwardly through the middle of the block it and is screw-threaded into the plate l9, there being a collar 25 fastened to the lower end of the screw 29 to keep the plate E9. There is a clearance between the block 18 and plate i8 so that the screw 20 may clamp them powerfully against the supporting guides 6 and l to hold the supporting member firmly in position. As the screw is tightened, plate I9 is turned automatically to the full line position, while when fully loosened it is turned to its dotted line position.

Referring now to the embodied form of the plate fastening and supporting means of the present invention, a plate clip is shown having a body portion 25 located in the clip-way I (Figs. 1 and 2) the body being formed in cross section so as to be supported slidably between the two pairs of guideways or supports 6, l, B and 9, and also held against upward displacement. The outer part of plate clip 25 is relatively high and has an integral, beveled clamping jaw 26 extending upwardly from the clip-way and adapted to clamp the curved bevel edge of the printing plate. The jaw above the cylinder is wider than the top of the clip-way and slides over the surface of the plate cylinder (Fig. 2) being fitted between the guideways 1 and 9. The inner part of the plate clip 25 within the clip-way is relatively low and there is a space between it and the plate 19, that is, it is cut down or relieved so that its cooperating plate-supporting member may be positioned above it and act as the support between the plate p and the cylinder, as hereinafter described. The plate clip 25 is threaded on a screwrod 2'5 rotatably mounted on the cylinder and located in and extending along the clip-way. The cooperating plate-supporting member, which supports the plate p right to the beveled edge, and takes part in the clamping operation, by supporting the edge of the plate opposite the jaw 26, comprises a body part 31 (Figs. 1, 3 and 4) which is slidably supported in the clip-way l. The upper part of the body 3! (Fig. 4) extends over and is supported on the inwardly-projecting guideways 6 and 1, and the lower part of the body extends laterally below guides 6 and l, and is slidable loosely between the guideways 6 and 8 and l and 9. The body 3| is thus firmly supported and is held against vertical displacement but is slidable along the clip-way. It has been previously stated that it is preferably ground in place in the cylinder so as to have a true surface with the cylinder but extreme accuracy in the fit is not essential and even considerable wear does not permit movement of the plates. The body portion 3| of the support is threaded on the screw-threaded rod 21, and as the rod is turned the plate clip 25 and this supporting member 3| move together and always maintain their relative position.

As shown in the drawings, the parts which need not be accurately fitted are shown with an exaggerated clearance, while the other parts are either finished to a true surface or a sliding fit.

Integral with the body SI and extending outwardly therefrom to the beveled edge of the plate is an extension 32 (Figs. 1 and 3) which with the body 3! was ground to true cylinder height and form during the grinding of the cylinder. Said extension 32 fills the clip-way laterally and rests upon and is supported by the upper surfaces of the guiding supports 6 and 1, and its upper surface is exactly flush with the cylinder surface and is directly underneath the plate acting as a direct support between the plate and the cylinder. This plate-supporting extension 32 is slidably supported on the guideways '6 and 1 and fills the upper part of the clip-way and is exactly flush and true with the surface of the cylinder. It extends outwardly over the inner, low or cut down partof the plate clip (Figs. 1 and 3) to the bevel edge of the plate, and supports the edge of the plate beneath the pressure of the clamping jaw, and having been ground with the cylinder its supporting surface is always exactly true and alined with the cylinder surface, and will neither lift the printing plate nor permit it to be bent downwardly by the clamping pressure.

In Fig. 1 is shown an embodiment of the invention suitable for use between two plates p and 10' side by side at an end of the cylinder. As shown, a double clamp mechanism has two oppositelyfaced plate clips Al and Q2, of substantially the same structure and mounted in the clip-way E, as already described, and as shown in Figs. 1 and 9. The respective plate clips have oppositelyfaced plateclamping jaws 43 and 44, one engaging the inner bevel edge of the plate 10 and the other the outer bevel edge of the Plate 10, there being a spacing block 45 interposed between them to give the proper margin gutter. A plate-supporting extension member 48, similar in structure and function to the extension 32 is shown beneath the plate 1) and cooperating with the jaw 43 of the plate-clip 4|, and it operates similarly to the member 3|, as previously described, The plate-clip 4i and its cooperating supporting member 48 are held together in the described relation by suitable means, and as here shown a screw-bolt 5| extends through a horizontallydisposed aperture in the supporting member 48 with its head 52 abutting on the face of the member 8, and the bolt being screw-threaded at 53 into the body of the plate-clip 4|. Beyond the screw-bolt 5| is a pin 54 which extends through an aperture in the spacing block 45 and into an aperture in the body of the clip 42, serving to hold the block 45 in the groove. The plate-supporting member 5?, which cooperates with plateclip 42, has the same general structure and function as the plate support 3!, but as a matter of mechanical convenience it may be variably positioned and then held in fixed position in the clipway by fastening means similar to that shown in Fig. 5.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is: 1. In combination in a printing press, a plate cylinder, a clip-way in the cylinder, a plate-clip slidably mounted in the clip-way and having a clamping jaw to engage a beveled edge of a printing plate, a plate support slidably mounted in the clip-way beneath the printing plate and supporting the plate substantially to said beveled edge where it is engaged by the clamping jaw, said jaw and plate support having slight relative radialrnovement due to their loose fits in the clip- '2; In combinationin a printing'press, a plate cyli'nden'a clip-way in the cylinder, a plate-clip slidably mounted in the clip-way, and having a clamping jaw to engage a beveled edge of a printing plate, a plate support slidably mounted in the clip-way beneath the printing plat and supportingthe plate substantially to said beveled edge where it is engaged by the clamping jaw, and means for moving the clip axially of the cylinder andholding it in position and means for separately supporting the jaw andplate support on the cylinder so that they are independently movable.

3'. In combination in a printing press, a plate cylinder, a clip-way in the cylinder, a plate-clip having a body slidably mounted in the clip-way, and havinga low inner part within the clip-way, said plate-clip body having at its outer enda plate-clamping jaw extending above the clip-way toengage the beveled edge of a plate, a platesupport slidably mounted in the clip-way beneath a plate, said plate support having a part extending outwardly above said low inner part of the plate-clipand supporting the plate substantially to said beveled edge where it is engaged by the clamping jaw, said jaw and plate support being separately supported on said cylinder.

4. In combination in a printing press, a plate cylinder, a clip-way in the cylinder, a screw-rod in theclip-way, a plate-clip having a body slidably mounted in the clip-way and threaded on saidscrew-rod, and having a low inner part within'the clip-way, said plate-clip body having at its outer end a plate-clamping jaw extending above the clip-way to engage thebeveled edge of a plate, a plate-support slidably mounted in the clip-way beneath a plate, and threaded on said screw-rod, said plate-support having a part extending outwardly above said low inner part of the plate-clip and supporting the plate substantially to said beveled edge where it is. engaged by the clamping jaw, said jaw and plate support having slight relative radial movement due to their-loose fits in the clipway.

5. In a printing press in combination, a plate cylinder, a clip-way in said plate cylinder, a screw-rod located in the clip-way, a plate-clip having a. body in the clip-way and screwthreaded on the screw-rod and having a bevel jaw at its outer end for clamping the bevel edge of the plate, and a plate-support located in the clip-way beneath the plate and having an outward extension eengaging the under surface of the plate, said outward extension being supported by the cylinder, and extending substantially to the beveled edge of the plate to support it at the point where the clamping pressure is applied and means for separately supporting the jaw and plate support on the cylinder so that they are independently movable.

6. In a printing press in combination, a plate cylinder, a clip-way in the plate cylinder having inwardly projecting supports extending along its side walls, a screw-rod located in the clip-way, a plate-clip having a body in the clip-way threaded upon said screw-rod, and having a plate clamping jaw extending above the clip-way to engage the bevel edge of a printing plate, and a low inner part beneath the plate, and a separate plate support in the clip-way beneath the plate and having an upper outwardly extending part supported on said clip-way supports and supporting the under side of the plate, said outwardly extending plate-supporting part extending over the inner part of the plate-clip body substantially to the plate edge where it is engaged by the clamping jaw, said plate clip and plate support being loosely fitted in the clipway with the plate support fiush with the cylinder surface and extending to a point immediately below the jaw portion of the plate clip.

7. In a printing press in combination, a plate cylinder, a clip-way in the plate cylinder having inwardly projecting supports extending along its side walls, a screw-rod located in the clip-way, a plate clip having a body in the clip-way threaded upon said screw-rod, and having a plate-clamping jaw extending above the clip-way to engage the bevel edge of a printing plate, and a low inner part beneathrthe plate, and a separate plate support in the clip-way beneath the plate threaded on said screw-rod and having an upper outwardly extending part supported on said clip-way supports and supporting the under side of the plate, said outwardly extending platesupporting part extending over the inner part of the plate-clip body substantially to the plate edge where it is engaged by the clamping jaw, said plate clip and plate support being loosely fitted in the clipway with the plate support flush with the cylinder surface and extending to a point immediately below the jaw portion of the plate clip.

8. In a printing press in combination a plate cylinder, a clip-way in the plate cylinder having a plurality of pairs of inwardly projecting supports extending along both its side walls, a screwrod located in the clip-way, a plate-clip having a body in the clip-way threaded upon said screwrod and having a plate-clamping jaw extending above the clip-way to engage the bevel edge of a printing plate, and a low inner part beneath the plate, and a plate support in the clip-way beneath the plate supported on said clip-way supports, and having an upper outwardly extending part supporting the under side of the plate, said outwardly extending plate-supporting part extending over said inner part of the plate-clip body substantially to the plate edge where it is engaged by the clamping jaw, said jaw and plate support being separately supported on said cylinder.

9. In a printing press in combination, a plate cylinder, a clip-way in the plate cylinder having a plurality of pairs of inwardly projecting supports extending along both its side walls, a screwrod located in the clip-way, a plate-clip having a body in the clip-way threaded upon said screwrod, and having a plate clamping jaw extending above the clip-way from said high outer part, and a low inner part and a separate plate support in the clip-way beneath the plate, threaded on said screw-rod, and supported on a pair of said clip-way supports, and having an upper outwardly extending part engaging the under side of the plate, said outwardly extending plate-supporting part extending over the inner part of the plateclip substantially to the edge where it is engaged by the clamping jaw, said plate clip and plate support being loosely fitted in the clipway with the plate support flush with the cylinder surface and extending to a point immediately below the jaw portion of the plate clip.

10. In a printing press in combination, a plate cylinder, a clip-way in said plate cylinder, a screw-rod located in the clip-way, a plate-clip slidable in the clip-way and threaded on said screw-rod and having a jaw for clamping the bevel edge of a printing plate, a plate support located in the clip-way beneath a printing plate and having a part supported directly by the cylinder and engaging and supporting the plate substantially to the beveled edge where it is engaged by the clamp, and means for separately supporting the jaw and plate support on the cylinder so that they are independently movable.

11. In combination in a printing press, a plate cylinder, and a plate clip movably mounted in the cylinder to engage a printing plate and hold it to the cylinder, said cylinder being provided with a plate supporting surface separate from the clip and movable relatively to the cylinder and plate clip and adjacent to the plate engaging portion of the clip for supporting the plate against the plate holding pressure exerted by the clip.

CURTIS S. CRAFTS.

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