US2549226A - Means for holding printing plates to rotary presses - Google Patents

Description

A ril 17, 1951 R. R. MYERS, JR 2,549,226

MEANS FOR HOLDING PRINTING PLATES TO ROTARY PRESSES Filed Sept. 27, 1948 2 Sheets-Sheet 1 T K/i 3)? l// J l 13 4 13 f'zzlenfloz" A ril 17, 1951 R. R. MYERS, JR 2,549,226

MEANS FOR HOLDING PRINTING PLATES TO ROTARY PRESSES Filed Sept. 27, 1948 2 Sheets-Sheet 2 a 2i, 7 4/); Margy Patented Apr. 17, 1951 MEANS FOR HOLDING PRINTING PLATES TO ROTARY PRESSES Robert R. Myers, Jr., Des Moines, Iowa Application September 27, 1948, Serial No. 51,466

2 Claims.

The principal object of my invention is to provide a method of successfully rigidly holding a curved printing plate to a rotary press during the printing operation.

A further object of my invention is to provide a means for holding curved printing plates to rotary presses that insures against the loosening of the plate during its use on the press.

A still further object of this invention is to provide a means for holding curved printing plates to rotary presses that reduces the cracking and breaking of the plate during the rotating of the press.

A still further object of this invention is to pro vide a means for reducing the wear on curved printing plates.

A still further object of my invention is to pro vide a means for and method of successfully holding printing plates to rotary presses that utilizes present existing printing equipment.

A still further object of my invention is to provide a means for rigidly securing curved printing plates to rotary presses that is economical in manufacture and use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangement, and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. 1 is a perspective view of a curved printing plate held to a rotary press by my method.

Fig. 2 is an enlarged sectional view of the method for rigidly securing the side of a printing plate to a rotary press and is taken on line 2-2 of Fig. 1.

Fig. 3 is an enlarged cross-sectional view of the means shown in Fig. 2, and is taken on line 3-3 of that figure.

4 is an enlarged perspective view of he block means for securing the front or back end of a curved plate to a press.

Fig. 5 is an enlarged longitudinal sectional view of the block means used in 1 is taken on line 55 of Fig. 1.

Fig. 6 is a top plan view showing the method of cutting holes in the front and back of the printing plate.

'7 is a side sectional View of the means shown Fig. 6 and is taken on line 5-? of that figure.

One of the problems of rotary printing presses is the securing of the curved printing plates to the press cylinder. The usual method is to bevel the marginal edges of the plate and use clamps that overlap such bevel edges and are secured to the drum frame. However, such clamps when used at the front and back ends of the plate have a tendency to further curve the plate and bow its center portion away from the drum press. This means that each time the plate is used for printing, the pressure will move the center portion in wardly onto the drum frame, and such constant bending action causes the plate to rapidly break down and crack along its transverse center line. Also such clamp blocks rapidly eat into the soft backing metal of the plate and the plate therefore quickly becomes loose on the press. This is true of all edge portions of the curved plate. I

have overcome such problems as will hereinafter be appreciated, but first will described presentday equipment and the method of using same.

Referring to the drawings, I have used the numeral Hi to designate a curved printing plate having all of its four side edges I l beveled. The printing surface is of the usual hard metal shell, but the major portion is made up of soft metal backing material placed 011 the back of the shell at the time of manufacture. Most all rotary or cylinder press drums are of cylindrical construction with spiral grooves 13 cut therein, or the cylinder may be made of a plurality of spaced apart spiral bars, as shown in Fig. 1, with the groove cut in each of the bars 12. Such bars, or cylinders with grooves, have a toothed track M in the bottom of each of the grooves. Also such grooves are of the tongue and groove type in that each groove has two laterally and oppositely extending grooves l5 and 16 in its side walls, respectively. It is common practice to use clamp blocks ii in such spiral grooves 83. In general such blocks have a worm gear 19 extending through the bottom of the block for engagement with the toothed rack M, and a second worm gear 2t in the block and in engagement with the gear 19. A crank or like Wrench 2| is used to manually rotate the worm gear 2!} for moving the block forwardly or rearwardly in the groove 13, as shown in Fig. 5. Such blocks also have a rotatably mounted beveled cleat 22 designed to overlap and engage the beveled portion of a printing plate as shown in the drawings. The beveled cleat 22 also has two oppositely extending finger flanges capable of extending through slits in the block and entering and slidably engaging the grooves l5 and 16, respectively, when the beveled cleat is manually rotated to a substantial cross position on the block.

and tighten onto the bevel I l of the plate.

By rotating the cleat 22, relative to the block, the flanges 23 are withdrawn from engagement with the side grooves l5 and [5. Usually the beveled cleat is rotatably mounted on the block directly above the gear 20, and a hole 24 is provided through the cleat so that the tool 2| may be inserted and-reach the bevel gear 20. Usually a second set 25 of finger flanges are rotatably secured in the block, also capable of being rotated through side slits in the block for engagement with the side grooves I5 and It. This rotation of the flanges 25 is accomplished by a stud 26 secured thereto and extending to the top surface of the block, as shown in Fig. 1. The head of this stud may be a Phillips type or any suitable design to take a wrench for operation similar to the rotation of the gear 20. The usual procedure is to place the blocks in the spiral grooves at all sides of the plate, then rotate the cleats for engagement with the plate thereby extending the flange fingers 23 into the side grooves, also rotating the stud 26 to bring the flange fingers 25 into the side grooves l5 and I6. The finger flanges 25 are to the rear of the beveled cleat, to expose the stud 26. With the side grooves i5 and I6 so engaged, the block will be fastened in the groove l3, but may slide forwardly or rearwardly therein, by rotating the worm gears. By so moving the block toward the plate the cleat will overlap This heretofore means for securing a plate to a press works somewhat satisfactorily for the side edges of the curved plate, but when applied to the front and bottom ends of the plate, the tendency is to further how the plate and trouble quickly results. Even the blocks at the sides of the plate are not completely successful however. They have a tendency during the printing phase to bite into and wear the soft backing metal of the plate, whereby the plate will become very loose on the drum after a little usage. Obviously, when a plate becomes loose, not only will breakage be possible, but poor printing will result. This is especially true of multicolor printing where the plates must accurately register.

The procedure and equipment heretofore described is common to the art and I lay no claim to the same. My invention resides in slightly changing the same and making a different setup, whereby the plate will be successfully and rigidly held on the press throughout the printing phase. I will now explain my invention in detail.

To hold the beveled side edges of the plate to the press I use the same method and equipment heretofore described and which is old in the art. However, to prevent the cleats of the block from seriously eating into the marginal edge portion of the plate, I cast into the two side portions of the plate at time it is manufactured, a strip of relatively hard metal 27, such as brass, copper, or like. When the plate is machine beveled these side strips will be embedded into the relatively soft backing metal of the plate, as shown in Fig. 2. By this arrangement the beveled holding cleats 22 will contact the relatively hard metal strips 21, and will thereby be prevented from eating into the soft backing metal of the plate. Thus the side edges of the plate will be successfully, tightly and rigidly held onto the press and this desirable condition will continue throughout the printing. Also the aligning of the plate on the press will not only be facilitated, but will be maintained. While this arrangement is successful for the side edges of theplate, it will not be for the front and rear end edges of the plate, for the simple reason that the rotating of the bevel gears of the blocks at these ends of the plate for moving the blocks toward the plate would only promote the bending of the curved plate. Therefore, to hold the front and rear edges of the plate to the press, such edges must be drawn in a direction away from the center of the plate, and, not pushed toward the center as has been done heretofore. To accomplish this, I reverse the blocks at the front and rear ends of the plate, as shown in Fig. l and Fig. 5. This places the stud 26 under the marginal edges of the plate. These studs 26 are drilled and topped to take a Phillips or like headed screw '28. A hole is formed in and .through the marginal edge portions of the plate that overlap each of the studs 26. By placing the screws 28 through these holes in the bottom and top ends of the plate, and threading the same into the prepared studs 26, the upper and lower end portions of the plate will be rigidly secured to the blocks H adjacent thereto. By rotating the worm gears of these blocks, they will, due to their reverse arrangement, back away from the plate, thereby pulling on the plate from both ends. This action is distinguished from the pushing action performed by the blocks at the sides of the plate. 7 Obviously, by pulling outwardly on the two ends of the plate it will beheld tightly and rigidly on the press and all undesirable bowing action will be elimihated. To remove the plate the screws 28 are removed and the Worm gears of all the blocks are rotated in a direction to cause the blocks to move away from the plate. From the foregoing, it will be appreciated that I have solved the problem of not only successfully holding the sides of a curved printing plate to a press, but also the ends.

One problem, however, is the forming of the holes in the end portions of the plate so that they will register with the threaded studs 26. To accomplish this, any suitable gauge punch may be used. In the drawings I use the numeral 29 to designate the base of such a punch. This base is of a dimension similar to the blocks ll, so that it will fit into and slidably engage a groove i3. It has a mouth 39 to receive the marginal edge of the plate, as shown in Fig. 7. The numeral 3| designates a vertical passageway extending through the base and cutting through the mouth 33. The numeral 32 designates the punch rod threaded in the passageway 3! above the mouth and capable of being screwed to a position where its end will pass below the mouth. The position of the vertical passageway back from the forward end of the base is exactly equal to the distance from the forward end of a block I! and a screw 28. The numeral 33 designates a handle on the punch rod. To cut a hole in the plate itis merely necessary to place the punch means in the groove i3, (which will later be used by a block I1) and slide the punch toward and onto the plate as far as it will go, and then operate the plate. The punch means is then removed and upon the placement of a block ll in the groove, it will be found that the hole 34 formed by the punch will be directly over the threaded stud 26. The punch rod should also be so formed, as shown in Fig. 7, to form a counter sunk perforation so that the head of the screw will, when tightened, be flush or below the surface of the plate.

With the block properly under the edge of the plate, it is first screwed forwardly until the cleat contacts the beveled edge of the plate, and can go no further. Obviously, the punch was also a jig, and at this time the hole in the plate will be directly over the threaded stud 26. It is then a simple matter to insert the screw 28 and fasten the block to the printing plate. After the plate is secured to the blocks by the screws 28, the blocks are screwed in the opposite direction to pull the blocks aways from the plate and thereby tighten it on and to the press. The cleats of these blocks also aid in securing the marginal edge of the plate to these blocks, although the main burden is that of the screws 28.

Some changes may be made in the construction and arrangement of my method of and means for holding printing plates to rotary presses Without departing from the real spirit and purpose of my invention, and it my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim: g V

i. In combination with a spiral track frame of arotary press; said spiral track being of a plurality of spiral toothed dovetailed grooves, and a printing plate having reinforcing strips in its side marginal edges, a plurality of block members surroundin said printing plate and slidably resting in some of said dovetailed grooves, rotatable cleats on each of said block members capable of engagement with the marginal edge of said printing plate, worm gear means incorporated in each of said blocks and in engagement with the teeth of the dovetailed groove in which they operate,

and screws extending through the upper and lower marginal edge portions of said plate and operatively threaded into adjacent block members; said Worm gear means in the blocks at the sides of said plate being used to move the blocks in a direction toward said plate and the Worm gear means in the blocks at the upper and lower ends of said plate used to move the blocks in a direction away from said plate.

2. In combination with the frame of a rotary press; said frame being of a plurality of spaced apart spiral, dovetailed grooves each having teeth therein and a printing plate having spaced apart holes in its upper and lower marginal edge portions, a plurality of block members surrounding said printing plate and slidably resting in some of said dovetailed grooves, rotatable cleats on each of said block members capable of engagement with the marginal edge of said printing plate, worm gear means incorporated in each of said blocks and in engagement with the teeth of the dovetailed groove in which they operate, and screws extending through the holes in said printing plate and detachably threaded into adjacent block members; said Worm gear means in the blocks at the sides of said plate being used to move the blocks in a direction toward said plate and the worm gear means in the blocks at the upper and lower ends of said plate used to move the blocks in a direction away from said plate.

' ROBERT R. MYERS, JR.

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

UNITED STATES PATENTS Number Name Date 1,961,797 Smith June 5, 1934 2,180,732 Durham Nov. 21, 1939 2,224,555 Sweet Dec. 10, 1940 2,406,883 Luehrs' Sept. 3, 1946

Images