US2115468A

US2115468A - Means for attaching printing plates

Info

Publication number: US2115468A
Application number: US105754A
Authority: US
Inventors: Henry C Osborn
Original assignee: Multigraphics Inc
Current assignee: AB Dick Co
Priority date: 1936-10-15
Filing date: 1936-10-15
Publication date: 1938-04-26
Anticipated expiration: 1955-04-26

Description

April 26, 1938. H. c. OSBORN MEANS FOR ATTACHING PRINTING PLATES Filed Oct. 15, 1936 INVENTOR 2 Sheets-Sheet l BY & 1

(9% @Mw @M ATTORNEYS) April 26, 1938. H, c, OSBORN I 2,115,468

MEANS FOR ATTACHING PRINTING PLATES File d Oct. 15, 1936 2 Shets-Sheet 2 ATTORNEYS Patented Apr.'26, 1938' UNITED STATES PATENT OFFICE MEANS FOR. n'r'mcnme Pmfi'rme m'ras Henry C. Osborn, Cleveland, Ohio, assignor to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Application October 15, 1936, Serial No. 105,754

4 Claims. 101-4151) which maybe made of metal, paper or other comdoubled backwardly on itself as at 2|. The 5 position. doubling is made by rounding the strip in the An object of the invention is to provide an'atfolded region in a partially tubular form, inditaching member which may be very readily cated at 22. Such rounding extends from one mounted on the plate, across the end thereof, and face of the strip for'substantially a semi-cylinder,

will cooperate with an anchorage device on a suitthen continues toward the opposite face for sab- '10 able drum of a printing machine to enable the stantially a quarter cylinder, where it merges into plate to be drawn taut about the drum and held a flat portion. The end of this flat portion is thereon. preferably doubled inwardly as at 24 to make 2.

Another object is to provide a. metal attaching smooth, reinforced edge. The head provided by l5 device suitable for ready cooperation with a paper the open tubular rounding at the bend materially l5 This invention relates to means for securing printing plates on cylinders of presses. The means employed are especially'well adapted for attaching very thin flexible planographic plates,

plate so that the plate may be effectively attached without danger of it being torn or injured.

. Still another object is to soform the attaching device that-while being readily mounted on the end of the plate it will obtain such grip thereon that it will not allow the plate to shift laterally relative to the attaching device.

My invention is illustrated in the drawings hereof and is hereinafter more fully explained and the essential novel features are set out in the claims.

In the drawings, Fig..-1 is a plan, intermediately ing devices on the two ends thereof; Fig. 2 is a fragmentary view of the attaching device and an end portion of the plate, showing the attaching device as it is being mounted on the plate or removed therefrom; Flg. 3 is a fragmentary crosssection on the line 33 on Fig. -1, showing the attaching device and plate interlocked with each other; Figs. 4 and 5 are cross sections of the attaching device in different regions, as indicated by the lines 44 and 55, respectively in Fig. 2; Fig. 6 is a longitudinal section through the attaching device looking toward the doubled end thereof; Fig. '7 is a cross-section ofa portion of a planographic printing machine with a plate held by my attaching device Fig. 8 is a view illusends doubled over onto the back of the plate, as and thus stretches the plate It about theEdrum, indicated at I l in Fig. 8 and in exaggerated form While my attaching means is suitable forLany in Fig. 3, If this plate is of paper, a few-thousort of a press employing a tl...1 plate, it may trating the connection of the attaching device to the anchorage member on the drum, being a plan looking in the direction indicated by the arrow designated 8 on Fig. '7. I

In Figs. 1, 2, 3, '7, and 8, l0 indicates a print ing plate, which is a very thin sheet with its two.

sandths of an inch thick, the folding of the end will be quite abrupt, the folded over ply leaving the main body of the sheet at a comparatively bent or otherwise distorted.

taching device is formed to cooperate with a suitsharp and very acuteangle, almost parallel with the body of the sheet.

The attaching device designated 20 comprises a fiat, thin strip of metal or other strong material,

stiflens the attaching device and prevents it being In use the doubled ever end H of the printing plate lies within the confines of the doubled-over portion of the attaching device, each thus hooking 2 into theother. This hooking action is of such a snug character that theplate cannot be pulled out of the attaching device by the tension used in anchoring the plate on the drum.

To effect the mounting to the drum, the at- 2 able anchorage member on the drum. As shown, I have formed the attaching device with its free edge scalloped, as shown at 25,. and provided suitable elongated openings 26 through the attaching device at each of the ears formed by the scalloping. These perforated ears are adapted to be mounted in pockets in the anchorage device with the openings occupied by suitable projections of such anchorage device, after the manner of the anchorage of the scalloped perforated plate set out in Patent No. i,96'7,221, of Allen and Hartley.

Referring to Figsfll and 8 hereof, indicates a suitable drum on which the plate is shown as mounted. This drum isprovided with a fixed bar 3 I having pockets and projections 32 over which one of the attaching devices may be placed, and with a movable bar 33 having corresponding pockets 3! and projections 35 onwhich the other attaching device may be'mounted. The bar 35 is pivoted to the drum at 36 and carries screws 31 which at their ends abut a shoulderv 38 on the drum. When the screws are turned in, this forces the anchorage device away from such "shoulder 2. and 50 a roller carrying a transfer blanket in case of offset lithography or acting as an impression platen in direct printing.

The doubled over end ll of the plate In is inserted in thegrip of the attaching device by being shoved laterally into place. The operator, by grasping the attaching device with one hand and the edge of the plate with the other, may insert the doubled end or the plate into the end of the pocket provided by thedoubled portion of the attaching device, and then, by a lateral shoving action or a pull on the other edge of the plate, cause them to come into the mounted position shown in Fig. 4. v

To enable the mounting of the attaching device on the plate, I space the doubled-over portion of theattaehing device from the body of the device a distance slightly greater than the thickness of the plate. For instance, if the plate be .010 inch thick, I find .011 inch spacing facilitates insertion of the device.

When the device is to be used with plates ofv certain type of materials, I find that a firmer grip on the plate is desired. In such instances I make the doubled-over portion of the attaching device near the edges a very slight distance farther from I the body of the attaching device than it is in the main portion of its extent. This is illustrated in Figs. 1, 2, 4,5 and 6. Theendmost regions of the doubled-over portion indicated by the designation a and by the cross-section Fig. 4, provides a space sufiiciently greater than the thickness of the plate so that the flanged edge of'the plate may be very readily inserted. The intermediate region, indicated at b in Figs. 1 and? and shownby the cross-section in Fig. 5, has the doubled edge of the attaching device slightly closer to the plate, so that such intermediate region engages the plate with such snugness that considerable push or pull is required in mounting the plate.

The result of the construction'just described is that when the plate and attaching device have I are veryeflectively" been mutually mounted, they held together, preventing any lateral shifting of the plate with reference to the attaching device, as well aspreventing the attaching device being pulled from the plate even if an abnormal .force is applied by the plate tensioner.

In my means for attaching the plate, the metal strip is made quite thin and the plate with its two. attaching devicesare adapted to be main-..

tained in the same machine alternatively with the integral metal of plates of-the Allen and Hartley patent mentioned.v When so mounted, the attaching devices are within the circumference of the drum,- as illustrated in Fig. 7, and are thus free from engagement with the inking rollers or the plate engaging roller 50.

tion, that I have obtained very satisfactory results by using a paper plate .010 inch thick, and a metal strip .015 inch thick, and allowing a gap between the central region of the doubled over portion of the attaching device and the body of .008 inch, with the gap adjacent the ends .012 inch.

The thinness of my attaching devices enables plateswith these devices attached to be readily stacked, one above the other, for storage purposes. The plate is easily secured to the attaching device, and when secured is so firmly attached that the plate with the two devices may be treated in use as one unitary" structure.

I claim:

v1. An attaching device for a printing plate having a doubled-over end comprising a member having a body portion and a backwardly projecting edge providing an elongated pocket into which the doubled-over edge of the plate may extend, the intermediate portion of. said pocket having a narrower mouth than the extreme. portions.

, 2. An attaching device for a printing plate comprising a strip provided with op n s a an edge portion of the strip bent backwardly substantially parallel with the body thereof, the intermediate region of the edge portion being closer to the body than the end regions thereof.

3. An attaching device having a doubled-over end, comprising a metal strip having a flat major portion with perforations and a minor doubled-over portion substantially parallel with the major portion, said doufor a printing plate.

bled-overportion extending for substantially the width of the strip and'lying comparatively close to it throughout its length but being slightly farther away from the body of the strip for a short distance adjacent the end of the doubledover portion than it is throughout the interme- "diate region of the doubled-over portion.

4. In combination with a paper'printing-plate having its end folded over abruptly and .a thin metal-attaching device, having its end portions opposite the-.doubled-over portion and don-- bled-over end' of the printing plate extending into such tubular portion, whereby said print- -ing plate may be readily slid into interlocking engagement with the attaching device, even though the extreme'end of the printing device he frayed from use.

HENRY c. osBoaN.