US2756675A - Printing plate clamping device - Google Patents

Description

July 31, 1956 A. J. MONACO PRINTING PLATE CLAMPING DEVICE 2 Sheets-Sheet l 7 Filed July 8, 1949 July 31, 1956 A. J. MONACO PRINTING PLATE CLAMPING DEVICE 2 Sheets-Sheet 2 Filed July 8, 1949 INVENTOR Albert J. Monaco BY /6M NEY ited States atnt g nted uly 31, was

PRINTING PLATE CLAMPIN G DEVICE Albert J. Monaco, Bellerose, N. Y., assignor to National Lead Company, New York, N. Y., a corporation of New Jersey Application July 8, 1949, Serial No. 103,656

2 Claims. 01. 101385) This invention relates to printing devices and more particularly to appliances for clamping or locking printing plates on a cylindrical supporting bed which is positioned on the printing press.

It is the object of this invention to provide a clamping device for printing plates adapted for use in conjunction with cylindrical supporting beds or plates. It is a further object of this invention to provide a clamping device which is capable of rapid actuation so that the use of the device will expedite the mounting and planning of printing plates. A further object of the invention is to provide a clamping device which may readily be removed from the supporting bed, yet, will remain in position in the bed when the cylindrical supporting bed is in various positions. These and other objects of the invention will be apparent from the following description of the invention and from the drawings which illustrate a preferred embodiment thereof and in which:

Fig. l is a plan view of a portion of a supporting bed having a printing plate positioned thereon, locked to the bed by employment of clamping devices according to this invention.

Fig. 2 is a section taken along the lines 22 of Fig. 1.

Fig. 3 is a front elevation of the body portion of the clamping device of this invention.

Fig. 4 is a sectional view of the device of Fig. 3 taken along the lines 4-4.

Fig. 5 is an expanded rear view of the various elements in the device of this invention disposed in relative position for assembly.

Fig. 6 is a side view of the clamp spring shown in Fig. 5.

Referring now particularly to Fig. 1 and 2, the cylindrical supporting body 10 is provided with a number of tapered perforations 11, which are provided adjacent to their inner extremities with expanded portions 12 which form with the tapered portions, shoulders 13. Position on the top surface of body 10 is illustrated printing plate 14 which is provided with beveled edges 13. The printing plate 14 is fixedly maintained in position with the surface of bed plate 10 by the clamping devices of this invention represented generally at 16. These devices, more particularly illustrated in Figs. 3, 4, 5 and 6, comprise a a slotted shank or body member 17 having a jaw 18 which is formed at its upper edge to provide a beveled plate or engaging surface 19. The body portion 17 is preferably of an elongated design and substantially oval in cross section with a groove or guideway 20 formed in the side and rear base thereof for reception of a movable block engaging element 21. The element 21 is substantially of the configuration shown and may be described as being of U-shape. The arms or sides thereof are arranged so that the top portion which engages the wall of the block opening, as hereinafter described, is offset a considerable distance from the plane of the ends. The groove or guideway 20 is conformed to the shape of element 21, the base of the latter being contained within that portion of the guideway 20 which is located in the rear face of the body 19 when the element 21 is in normal 2 or non-clamping position. At the lower end of body member 17 are provided lateral extensions 22 to form a shoulder which may engage shoulder 13 in the perforation of the bed block to lock the clamping device in place as hereinafter described in more detail.

Actuation of the clamping device of this invention is provided by provision of a central bore in the body portion 17 terminating in an enlarged upper portion 23 which is threaded for engagement with the engaging screw 24, of which the upper half is enlarged as at 25 so that the latter may be rotated in an engagement with the threads of the bore 23. The lower end of the actuating screw is of reduced diameter as shown at 26 and is provided with left-hand threads adapted to engage the threaded bore of feeding element 27. This feeding element comprises a base 28 and legs 29. Attached to the rear face of body member 17 is a spring helding member illustrated in detail in Fig. 6. This spring member comprises an elongated base 30, preferably arcuate laterally, and a spring arm 31, downwardly retroflected thereon. Laterally and rearwardly extending from the edge of the base 31 are claws 32 by which the base portion of the spring member is clipped on to the body 17 by locking engagement of the claws 32 in the lower extensions of groove 20. When the spring member is assembled on the device, the spring arm 31 projects from the rear face of the body as shown in the sectional detail in Fig. 4 and is also clearly shown in Fig. 2, this being disposed on the opposite side of the device with respect to the extending plate engaging jaw 18.

It will be apparent from the drawings and the description thus far that when the components of the clamping device are in assembled relation so that the portion 26 of the actuating screw is in engagement with the threaded bore of the feeding element 27, the base of the latter which is enlarged intermediate legs 29 will be disposed within the complemental portion of the transverse slot in the body member or shank 17, the legs 29 of the feeding element ride within the outer portions of said slot and are substantially in alignment with the ends of element 21. Rotation of the head of engaging screw 24 by means of an appropriate insertable tool 33, .due to the right hand threads, the rotation of this screw to the right will cause it to travel towards the head of body member 17, the feeding element 27 thereby being moved in the same direction by action of the portion 26 being threaded therethrough. As the feeding element 27 travels upward, by rotation of the lower end 26 of the engaging screw, the upper ends of the legs 29 will abutt against the lower ends of the element 21 to cause the latter to move upwardly within the guideway or groove 20. Due to the shape of the member 21 of the corresponding design of the groove 20, upward movement of element 21 will result in an additional outward or rearward motion of top portion thereof. Therefore, when the clamping device of this invention is positioned within an opening 11 on supporting block 10 so that the lateral extensions 22 against the shoulder 13 at the base of the opening in the block and the face of the jaw 19 in contact with the beveled edge 15 of printing plate 14, it will be seen that upward and outward movement of element 21 will produce a wedging action as the top of this element contacts with, and presses against, the inner wall of the opening in the supporting bed or block. The position will be susbtantial- 1y that shown in Fig. 1 wherein the top of element 21 is extended from the body 17 and contacting the wall of perforation 11. It will be obvious that as the element 21 is forced outwardly from this guideway or slot 20 against the interior wall of perforations 11, a corresponding counterpressure will be exerted by the face 19 of the jaw 18 against the beveled edge 15 of the printed plate and when several of the devices are employed in cooperating positions as shown in Fig. 1, the plate 14 may be firmly and immovably locked in position.

When it is desired to release the plate, the feeding element 27 is caused to recede from engagement from the ends of the block engaging element 21 by turning the actuating screw 24 in a reverse direction by means of insertable tool 33. The element 21 may then be moved into the groove .or guideway 20 by applying pressure to the upper portion or body member 17 so as to move it away from the edges of plate 14. The plate 14 is thereby released and the clamping device may be disengaged from the beveled edges, 15, thereof.

If desired, the clamping device 16 may be readily completely removed from the perforations, 11 as will be evident. However, due to the novel construction and arrangement, including the spring member 39, the clamping devices will be normally maintained in their respective perforations unless forceably removed. This is accomplished by tension engagement of the spring arm 31 against the sides of the perforations 11 particularly in the vicinity of shoulder 1.3. Provision of the spring member insures the maintenance of the clamping devices in their respective perforations even when the. bed plate is rotated into positions from which they would normally fall out. Thus, a new set of plates may be positioned on a cylindrical bed plate without completely removing the clamping devices. This feature is particularly advantageous when a number of similar sized plates are to be employed and one may be removed and another substituted without completely removing the clamping devices. It is often convenient to remove a complete set of plates from the entire surface of a cylindrical bed plate and during this operation, some of the clamping devices will inevitably be positioned at the underside of the cylinder. The locking spring feature maintains these in their respective perforations ready for re-engagement with another plate without removal and replacement.

While this invention has been described and illustrated, it is not intended to be strictly limited thereto and other modifications and variations may be employed within the following claims.

I claim:

1. In a printing plate clamping decive, the combination of a grooved body, having a U shaped member movable therein, and a spring element comprising an elongated laterally arcuate base portion, a downwardly retroflected spring arm, and claws projecting rearwardly from said base, said spring elements being detachably attached to said body by locking engagement of said claws in the groove therein, the spring arm providing a tension force close to the bottom of the clamping device.

2. A spring element adapted for maintaining a printing plate clamp in a perforation in a supporting bed, comprising, an elongated laterally arcuate base, a downwardly retroflected spring arm and claws projecting rearward ly from said base.

References Cited in the file of this patent UNITED STATES PATENTS 1,026,767 Quiggan May 21, 1912 1,379,936 Quiggan May 31, 1921 1,480,300 Quiggan Jan. 8, 1924 1,839,484 Burgrnann Jan. 5, 1932 1,908,497 Warnoick v May 9, 1933 2,059,067 Warnock Oct. 27, 1936 2,528,173 Pinckney Oct. 31, 1950

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