Saddle lockup for flexible printing plate

Abstract

A curved saddle for supporting and tensioning a flexible printing plate which has a series of closely spaced apertures along opposite edge portions. Each end of the saddle is provided with a circumferentially moveable spring biased bar having a series of spaced lugs over which opposite ends of the appertured plate may be positioned and secured. To facilitate positioning of the plate over the bar lugs, each bar has a locking mechanism which secures the bar in a retracted position upon manually moving the bar to that position. After a plate is secured to the bar, the locking mechanism may be readily released by depressing an actuating plunger, thereby permitting the bar to be urged under the spring biasing force to an outwardly extended plate tensioning position.

I claim as my invention: 
     
       1. A device for mounting a flexible printing plate to a press plate cylinder, comprising a curved saddle for supporting said plate about its outer surface, said saddle having the general shape of a sector of a hollow cylinder and having two straight ends, means at one end of said saddle for securing one end portion of said printing plate, a bar mounted at the other end of said saddle for movement toward and away from said saddle end, means on said bar for securing the other end portion of said printing plate, spring means interposed between said bar and saddle biasing said bar in a direction away from said saddle, means for locking said bar in a retracted position in close proximity to said saddle end, said locking means including an actuating plunger slidably disposed within said saddle end for axial movement in a circumferential direction relative to said saddle end, and means responsive to axial movement of said actuating plunger inward towards said saddle end for releasing said bar from said locking means to permit the bar to be moved outward away from said saddle end by the force of said spring means to tension the plate about said saddle. 
     
     
       2. The mounting device of claim 1 in which said locking means is operable to secure said bar in its retracted position in response to moving said bar to said position. 
     
     
       3. The mounting device of claim 2 in which said bar has an L-shaped cross section with one leg of said L being slidably mounted adjacent the underside of said saddle and the other leg of said L extending parallel to the end of said saddle, said other leg having a series of spaced lugs and said plate end portion secured by said bar being formed with a series of correspondingly spaced apertures which permit said plate to be hooked over said lugs. 
     
     
       4. The mounting device of claim 2 in which the said saddle end is formed with a socket within which said actuating plunger is disposed, said locking means including at least one ball element interposed between the outer surface of the actuating plunger and the socket walls, said socket having a recessed groove which receives said ball element when said bar is moved to the retracted position, an .[.abuttment.]. .Iadd.abutment .Iaddend.means associated with said bar engaging said ball element when the ball element is disposed in said groove to prevent outward movement of said bar, said plunger having a relieved section into which said ball element is received when said plunger is moved inward to a determined position so as to permit said ball element and said .[.abuttment.]. .Iadd.abutment .Iaddend.means to move beyond said recessed groove and allow said bar to move away from said saddle end. 
     
     
       5. The mounting device of claim 2 in which a ball carriage sleeve is secured to said bar, said actuating plunger being slidably supported within said sleeve, said saddle end being formed with a socket within which said ball carrying sleeve is slidably disposed, a spring interposed between the end of said actuating plunger and the end of said socket, at least one ball element interposed between the outer surface of the actuating plunger and the socket wall, said ball carriage sleeve having an aperture within which said ball element is carried, said socket having a recessed groove which receives said ball element when said bar is moved to its retracted position, said ball carrying sleeve bearing against a portion of said ball element when the ball element is disposed in said groove to prevent outward movement of said ball carriage sleeve and bar, said plunger having a relieved section which receives said ball element when said plunger is moved inward to a determined position, said ball element being free to move past said recessed groove when located in said actuating plunger relieved section thereby permitting the ball carriage sleeve and bar to be moved outward under the force of said spring means. 
     
     
       6. The mounting device of claim 4 in which said actuating plunger relieved section has oppositely tapered sides. 
     
     
       7. The mounting device of claim 5 in which the distance between the outer surface of said actuating plunger and the bottom of said recessed groove is approximately the diameter of said ball element and the distance between the bottom of the plunger relieved section and the socket walls is approximately the diameter of said ball element, and the depths of said recessed groove, the depth of said relieved section, and the thickness of said ball carriage sleeve each are approximately one-half the diameter of said ball element. 
     
     
       8. The mounting device of claim 4 in which said actuating plunger has a stem portion which extends through said bar to facilitate moving said plunger to its inward position. 
     
     
       9. A device for mounting a flexible printing plate to a press plate cylinder, comprising a curved saddle for supporting said plate about its outer surface, said saddle having the general shape of a sector of a hollow cylinder and having two straight ends, means at one end of said saddle for securing one end portion of said printing plate, an L-shaped bar mounted at the other end of said saddle for movement in a circumferential direction toward and away from said saddle end, said L-shaped bar having one leg slidably mounted adjacent the underside of said saddle and the other leg extending generally parallel to said saddle end, means on said other bar leg for securing the other end portion of said printing plate, spring means interposed between said other bar leg and saddle biasing said bar in a direction away from said saddle end, means responsive to retracting of said first bar leg to a predetermined position in close proximity to said saddle end for locking said bar in said retracted position, and means for selectively releasing said bar locking means to permit the bar to be moved in a direction away from said saddle end by the force of said spring means to tension said plate about said saddle. 
     
     
       10. The mounting device of claim 9 in which said other bar leg has elongated slots and is slidably mounted to said saddle by fastening means passing through said slots, said elongated slots defining the range of bar movement in the circumferential direction. .Iadd. 11. A device for mounting a flexible printing plate to a press plate cylinder comprising a curved saddle adapted to be conformably mounted on said cylinder and having the general shape of a sector of a hollow cylinder and having side edges and circumferentially spaced opposite end edges extending radially of said cylinder, means at one end edge of said saddle for securing one end portion of said printing plate, a bar extending along the other end edge of said saddle between said side edges of said saddle and having means for attachment thereto of the other end of said plate, said bar having a portion accessible for manual actuation, combined mounting and locking means positioned between said side edges of said saddle and substantially wholly within said other end edge of said saddle for mounting said bar for movement in a direction substantially circumferentially of said saddle between an inner plate release position adjacent said other end edge of said saddle and an outer plate tensioning position displaced from said other end edge of said saddle and for selectively locking said bar in said plate release position, and spring means carried by said other end edge of said saddle biasing said bar toward said plate tensioning position; said combined mounting and locking means comprising a sleeve rigid with said bar and slidably received in a bore in said other end edge of said saddle and locking means carried by said sleeve effective upon manual displacement of said bar inwardly to said plate release position for locking said bar in said plate release position, said locking means including a plunger slidably mounted in said sleeve and having an externally manually accessible operating portion extending through said bar, said plunger being effective, upon manual displacement axially inwardly of said sleeve, to release said locking means to permit the bar to be moved outwardly away from said other end edge of said saddle under the influence of said spring means to said plate tensioning position, and means for positively limiting movement of said bar away from said other end edge of said saddle. .Iaddend. .Iadd. 12. The device defined in claim 11, wherein there is a slidable connection between the bar and saddle disposed radially inwardly of the printing plate contacting outer periphery of said saddle, and said means for limiting outward movement of the bar is in said connection. .Iaddend..Iadd. 13. The device defined in claim 11, wherein there is a slidable connection between said bar and the saddle comprising a leg on the bar extending within a recess in said other end edge of the saddle, and said means for limiting outward movement of the bar is provided in said connection. .Iaddend..Iadd. 14. The device defined in claim 11, wherein said bar mounting means comprises a recess extending along said other end edge of the saddle and a leg on said bar projecting slidably into said recess, and said means for limiting outward movement of the bar comprises cooperating guide pin and slot means on said saddle and said leg. .Iaddend. .Iadd. 15. A device for mounting a flexible printing plate to a press plate cylinder comprising: (1) a curved saddle adapted to be conformably mounted on the cylinder, said saddle having: (a) the general shape of a sector of a hollow cylinder,   (b) side edges and   (c) circumferentially spaced opposite end edges extending radially of the cylinder;     (2) means at one end edge of said saddle for securing one end of the printing plate;   (3) a bar mounted on said saddle for limited movement in a substantially circumferential direction toward and away from the other end edge of said saddle and having means to secure the other end of said plate thereto;   (4) spring means interposed between said bar and said other saddle end biasing said bar in a direction away from said other saddle end; and   (5) combined locking and releasing means positioned between said side edges of said saddle and wholly within said other end edge of said saddle for selectively positioning said bar between a locked inner plate release position adjacent said other end edge of said saddle and an outer plate tensioning position displaced from said other end edge of said saddle; said combined locking and releasing means comprising: (a) a sleeve rigid with said bar and having an inner end slidably received within a bore in said other end edge of said saddle,   (b) a plunger slidably mounted in said sleeve and having an externally accessible operating portion extending through said bar, and   (c) locking means carried by said sleeve and said plunger inner ends,   (d) said locking means being effective to lock said bar in a plate release position adjacent said other end edge upon movement of said bar toward said other end edge and being effective upon displacement of said plunger toward said other end edge to release and permit said bar to be moved outwardly away from said other end edge of said saddle by said spring means to the plate tensioning position. .Iaddend.