US2375603A - Cylinder for printing presses - Google Patents

Description

May 8, 1945.

R. P. WILLARD CYLINDER FOR PRINTING PRESSES Filed Dec. 26 1941 Patented May 8, 1945 "um rap STATES PATENT OFFICE Moore Business Form Delaware 5, Inc., a corporation of Application December 26, 1941, Serial No. 424,481

8 Claim.

This invention relates to improvements in printing presses, and more particularly to an improved attaching means for attaching printing plates in operative position on the printing cylinders or other supporting surfaces of the printing presses.

It is a general object of the invention to provide an improved attaching means for attaching printing. plates in operative position upon supporting surfaces thereof, such as rotary printing l0 cylinders. The improved attachment embodies a simple and inexpensive structure that materially reduces the time and labor required for preparing the printing plate and applying it in operative position on the supporting surface of the print- 1 ing press such, for example, as a rotary cylinder thereof.

A further object of the invention is to provide an improved attaching means for attaching printing plates in operative position upon a supporting cylinder in such a manner as to avoid unbalancing of the cylinder and thus permitting rotation at high speeds without causing objectional vibration, thus materially improving the quality of the printing and at the same time increasing the speed of production of the printed matter.

Still another object of the invention is to provide an improved attachment for attaching printing plates in operative position and embodying an improved automatic self-adjusting attachment, automatically attaching the trailing or tail end of the plate in successive adjusted positions such, for example, as in cases where the plate in actual printing operation becomes slightly elongated due to slight stretching, to seating of the leading end attachment in finnly seated position, and probably also to other causes.

A further object of the invention is to provide tioned whereby the printing plate can occupy substantially the entire length of the supporting surface such, for example, as substantially the entire circumference of a printing cylinder, internal attachment of the trailing end of the plate with consequent recessing of the cylinder being sub stantially avoided.

According to another and more specific feature of the invention, an improved plate attaching arrangement is provided which is positioned substantially in the line of the plate supporting sur face, for example, substantially in the cylindrical surface of a rotary cylinder, thus avoiding the necessity of bending or offsetting the printing plate and facilitating the automatic reattachment of the plate following longitudinal adjustments thereof due to stretching or seating thereof more firmly into operative position, and also due to other causes.

Other objects and advantages of the invention will be in part pointed out in the following detailed disclosure of an illustrative but preferred embodiment of the invention, and will be in part obvious as the disclosure proceeds.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a more comprehensive disclosure of the nature, objects and advantages of the invention, reference is had to the following detailed description of the preferred illustrative embodiment and to the accompanying drawing, in which:

Fig. 1 is a fragmentary perspective view of a rotary printing cylinder embodying the improved attaching means for attaching a, printing plate in operative position thereon.

Fig. 2 is an enlarged fragmentary transverse sectional view of the cylinder of Fig. 1, showing the improved plate attaching means in greater detail.

Fig. 3 is a top plan view of one form of printing plate that may be utilized in connection with the invention; and

' Fig. 4 is a side elevation of the printing plate of Fig. 3.

, Referring now to the drawing for a detailed description of the illustrative'embodiment there shown, the printing cylinder 5 may be constructed in well known manner of metal or similar materialand is provided with journals, one of which is shown at 6, for rotatably mounting the cylinder an improved attachment of the character men- 40 in a printing press of known construction. This printing cylinder, as understood by those skilled in the art, will be mounted for cooperation with an impression or blanket cylinder and other printing press elements. The cylinder may be made of any desired length and diameter for accommodation of printing plates of appropriate size for production of the required printed matter, and may be made of sufficiently small diameter so that a plate six or eight inches in length, or even less, will extend substantially all the way around the cylinder.

This printing cylinder 5 is provided with a longitudinally extending slot 1 cut in the body thereof and preferably extending for the length of the cylinder as shown. This slot is small in transverse diameter so as to receive snugly an attaching flange at one of the terminals of the printing plate and will therefore vary in thickness in accordance with the particular printing plates employed. For a purpose later described, it will to accommodate the particular printing plates being used. This shallow groove 8 for clearness is shown somewhat exaggerated in depth in the drawing, and ordinarily it will be quite shallow, a depth of about .006 to .010 of an inch having been found to be satisfactory for ordinary purposes. Preferably, .as shown, the shallow groove 8 merges with the inclined attaching slot 1. The bottom of the shallow groove may be cylindrical concentric with the surface of the cylinder 5, or it may be fiat and substantially perpendicular at its transverse center to the cylinder radius. While, for illustrative purposes, a cylinder provided with a. single slot 1 and a single groove 8 has been shown, it will be understood that additional slots and grooves arranged as disclosed may be employed in cases where it is desired to attach more than one printing plate to the cylindrical surface.

Seated in the shallow groove 8 is an adhesive attaching device 9 shown in tlie form of an dhesive tape having adhesive material I both at the upper and the lower surfaces thereof. The adhesive at the lower surfaceattaches the tape in position in the shallow groove 8 while the adhesive at the upper surface is arranged for contacting with the under surface of the rear or following edge portion of the printing plate for attaching the same in operative position. For this purpose the shallow groove 8 and the attaching tape 9 are proportioned so that the upper adhesive attaching surface lies substantially in line with the cylindrical supporting surface of the cylinder. In other words, the upper adhesive attaching surface provides a substantially cylindrical extension or continuation of the cylindrical supporting surface of the cylinder. In this manner there is no interruption to the cylindrical supporting surface at the attaching edge of the printing plate, thus providing a true cylindrical outer surface for the printing plate at this attached edge portion thereof.

As mentioned above, it is desirable in some cases to construct the bottom or supporting surface of the shallow groove 8 substantially cylindrical and concentric with the cylindrical plate supporting surface of the cylinder 5. Thus, it is referred that the bottom of the groove be cylindrical in cases where the attching tape 9 is of considerable width, say about /2 or more. This maintains the upper adhesive surface of the tape substantially cylindrical in cases where the adhesive attaching tape is of uniform thickness throughout. A similar result can be obtained by making the bottom surface of the groove 8 substantially fiat and constructing the attaching tape of varying thickness with a cylindrical upper surface and flat lower surface so as to present the upper adhesive surface l9 thereof substantially cylindrical to form a cylindrical continuation of the supporting surface of the cylinder. In cases where the attaching tape 9 is quite narrow, from say to about th bottom of the groove 8 can be made flat and the tape of uniform thickness, since in this case the deviation from a true cylindrical surface of the upper adhesive supporting surface would be negligible. The tape widths mentioned are only approximate and would be different for cylinders of varying circumference, those given being for cylinders about 12" and less in circumference.

While the particular specific character of the adhesive attaching device may vary, an adhesive tape of textile fabric, tough paper, cellulosic sheet .material, or other flexible material has been found to be satisfactory. The adhesive I0 is preferably of th non-drying type and may embody rubber or latex such as the well known friction tape employed in electrical work. A very satisfactory adhesive for this purpose is the nondrying, pressure sensitive, cold sealing adhesive used in the product known as Scotch tape such as fully described in United States Letters Pgtgnt No. 2,177,627, Drew, dated October 31, l 3

One type of printing plate such as may be used in connection with the improved attaching device is shown in Figs. 3 and 4 of the'drawing, but other types of plates such as zinc lithographic plates may be utilized. As shown, this printing plate I l is in the form of a flexible sheet of metal, or cellulosic material such as any of the well known plastic materials, and is provided at its forward or leading edge with a downwardly inclined attaching flange l2. This attaching flange I2 is adapted to be received within the inclined attaching slot 1 and is inclined at an acute angle to the plate corresponding to the inclination of the slot 7 to the cylinder surface. In the form shown, printing plates l3 of rubber or similar material are adhesively attached to the upper surface of th base or supporting plate H. The upper surfaces of these rubber plates are formed with the data that is to be printed upon the paper or other material as well known in the art. A lithographic plate may be substituted for the rubber plates in which case the base plate ll would be made of appropriate material such as paper or zincjtheupper surface of which is provided with the data or design to be printed. The end portion of the plate H opposite to the attaching flange I2 is a straight continuation of the body of the plate and it is unnecessary to modify it in any way in order that it may cooperate with the improved attaching device for attaching the trailing end of the plate in operative position upon the cylinder.

When the cylinder has been prepared, as above described, with the adhesive attachment 9 in place, theprinting plate ll having the attaching flange I! can be quickly and easily placed in operative position upon the cylinder. It is only necessary to enter theattaching flange 12 in the inclined slot 1 and extend the plate upon the supporting surface of the cylinder until the trailing end portion thereof comes into overlapping relation with the adhesive attachment. When the plate has thus been positioned in close contact with the periphery of the cylinder, the trailing edge portion is pressed into firm contact with the upper adhesive surface ll] of the adhesive attachment. The pressure exerted along the edge portion of-the plate over the adhesive is sufficient to cause the plate to adhere firmly in position, whereupon the cylinder is ready to be started for the printing operation.

It will be noted that the inclined flange l2 engaging in the inclined slot I provides a hooklike attaching means for the forward end of the printing plate ll. When operation of the cylinder is started there may be some slight longitudinal adjustment or elongation of the plate II on the periphery of the cylinder due partly to the firmer seating of the flange in the inclined slot, partly to slight elongation or stretching of the plate, and partly to other causes. When this elongation occurs it will be seen that the adhe sive attachment of the trailing end of the plate is automatically adjusting. As the plate is elongated slightly in th manner suggested, the

' adhesive attachment will be released as operative rotation of the cylinder continues, and the plate will be automatically reattached in its adjusted position by the adhesive attachment due to continued rotation of the cylinder and the pressure exterted at the attached trailing edge by the impression cylinder or other cooperating element. In this manner the printing plate is maintained firmly supported in its various adjusted positions upon the cylindrical surface. tion it will be noted that the plate is free and unattached from the cylindrical surface of the cylinder except at its forward and rearward extremities so that the adjustments mentioned can be accomplished, the slight looseness during elongation being freely transmitted along the plate to the adhesive attachment.

It will be noticed that there is very little mutilation or cutting away of the cylinder 5 for adapting it for this improved plate attaching device. Consequently'there is little or no unbalancing of the cylinder and it can be operated a high speeds without causing any detrimental vibration such as might interfere with the quality of the printing. This is of particular importance where cylinders of small diameter are used, since they can be run at high speed so as to maintain large production. Since the attaching device requires very little circumferential space upon the cylinder, and the surface of the plate directly at the adhesive attachment can be utilized for printing, it will be noted that the printing surface of the printing plate can occupy substantially the entire periphery or nearly 360 of the cylinder thus resulting in a saving in material and speeding up of production.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. ,In a printing apparatus, in combination, a support having a supporting surface, a printing plate supported in operative position on said surface, a non-drying, pressure sensitive adhesive attaching device attaching one terminal portion of said plate in operative position upon In this connecsaid supporting surface, and a second attaching device for said printing plate spaced longitudinally of the latter from said adhesive attaching a device and firmly attaching the printing plate against longitudinal movement, said printing.

plate being supported by said supporting surface but free from direct attachment thereto intermediate said adhesive attaching device and said second attaching device, whereby said adhesive attaching device functions as an adjustable attachment for taking up slack or looseness of the printing plate.

2. In a printing apparatus, in combination, a support having a, supporting surface, a printing plate supported in operative position. on said surface, and an adhesive attaching device attaching one terminal portion of said plate in operative position upon saidsupporting surface, said adhesive attaching device including a nondrying pressure sensitive adhesive attaching surface positioned substantially in the line-of said supporting surface and substantially forming a continuation thereof, saidattaching device forming a support to support the attached terminal portion of the printing plate in operative printing position with its outer surface substantially forming an uninterrupted continuation of the main surface of the plate, said printing plate being supported by said supporting surface but being free from direct attachment thereto for a considerable distance along said supporting surface from said adhesive attaching surface which functions as an adjustable attachment for taking up slack or looseness of the printing plate.

3. In a printing apparatus, in combination, a support having a supporting surface and having a slot inclined to said surface, a printing plate supported in operative position on said surface and having at an edge portion an attaching flange extending into said slot, and an adhesive attachment attaching the opposite edge portion of said printing plate in position upon said support, said adhesive attaching device including a non-drying, pressure sensitive adhesive attaching surface positioned substantially in the line of said supporting surface and substantially forming a continuation thereof, and said printing plate being free from direct attachment with said supporting surface intermediate said attaching flange and said adhesive attaching surface whereby said adhesive attaching device is adjustable for taking up slack or looseness of the printing plate, said adhesive attachment forming a support for supporting said opposite edge portion substantially in the line of said printing plate as an uninterrupted continuation thereof.

4. In a printing apparatus, in combination, a support having a cylindrical supporting surface, a printing plate supported in operative position on said supporting surface, means for attaching ,with said shallow groove, a printing plate supported in operative position on said supporting surface, an attaching flange at the leading edge portion of said plate extending into said slot to provide an attachment for the plate, and a nondrying, pressure sensitive ahesive attachment in said shallow groove for attaching the rear or following edge portion of said printing plate in' operative position.

6. In a printing apparatus, in combination, a

rotary support having a cylindrical supporting surface for supporting one or more printing I plates in operative position and having a shallow groove opening outwardly through said surface, said rotary support also having a narrow slot rearwardly inclined to said supporting surface and merging with said shallow groove, and an adhesive attachment in said shallow groove for attaching the rear or following edge portion of a printing plate in operative position, said adhesive attachment supporting said rear edge portion substantially as an uninterrupted cylindrical continuation of said plate and having a non-drying, pressure sensitive adhesive surface i positioned substantially in the line of said cylindrical surface and providing an automatically adjusting attachment for the plate.

- 7. In a printing apparatus in combination, a rotary support having a cylindrical supporting surface and having a shallow groove opening outwardly through said surface, said rotary support also having a narrow slot cut in the body thereof. a printing plate supported in operative position on said supporting surface, an attaching flange at the leading edge portion of said plate extending into said slot to provide an attachment for the plate, and an adhesive attachment in said shallow groove for attaching the rear or following edge portion of said printing plate in operative position. said adhesive attachment including an adhesive tape having nondrying adhesive upper and lower attaching surfaces.

8. In a printing apparatus, in combination, a support having a supporting surface, a printing plate supported in operative position on said supporting surface, means for attaching the leading terminal of said plate in operative position on said supporting surface, and an automatically adjusting attachment for attaching the trailing terminal of said plate in operative position on said support, said automatically adjusting attachment being substantially immovable in a direction toward or away from said supported leading terminal of said printing plate and .forming in all of its different adjustments a support ing surface for said printing plate which is substantiaily an uninterrupted continuation of said first mentioned supporting surface, the said supporting surface of said adjusting attachment being positioned substantially in line with said nrst mentioned supporting surface so as to support said attached trailing terminal in any adjustment thereof substantially in the line of said printing plate whereby a continuous uninterrupted printing surface in operative printing position is provided extending from said first mentioned supporting surface to and over said supporting surface of said adjusting attachment. ROBERT P. WILLARD.

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