Improvements relating to printing plate clamping devices and the like

摘要

400,204. Printing-surfaces. CRABTREE & SONS, Ltd., R. W., Water Lane, and PHYTHIAN, T. E., 25, Headingley Mount, both in Leeds. April 14, 1932, No. 10759. [Class 100 (ii).] In a printing-machine having multi-plate printing-cylinders, clamping-devices are provided which clamp the plates yieldingly and whereby the plates after being clamped may be independently adjusted in position upon the cylinder in the lateral and circumferential. directions. The plate A is gripped by clamps b, c, slidably mounted on a shaft d which is arranged in a groove a3 in the cylinder parallel to its longitudinal axis. The inner end of the shaft d is screw-threaded to engage in a fixed block a4, a collar d2 being secured on the shaft to limit the movement of clamp c in this direction, and the outer end of the shaft projects beyond the usual clamping-up plate e, passing freely through a sleeve e1 which is adjustably mounted in the plate e and serves for the adjustment of a helical spring f mounted on the shaft d and bearing against the sleeve e1 on one side and against the outer clamp b on the other. 'The printing-plate A is clamped by movement of the plate e. when the clamp b is pressed against the plate A by the spring f, the pressure being transmitted by the printing- plate to the clamp c which is held in adjusted position by the collar d2. The inner plate B is provided with similar clamps b1, c1, mounted on a shaft d1, pressure from the spring f1 being transmitted to the outer clamp b1 through a sleeve g. Lateral adjustment of the plates A, B is effected by rotating the shafts d, d1, whereby the two clamps on each shaft move simultaneously, without change in their relative positions. For effecting the circumferential adjustment of the plates, a shaft h is provided and carries at its outer end a loose sleeve i. Adjusting stops j, k are provided for the plates A, B, respectively, and each stop is formed with a diagonally-disposed groove j2, k2, in which is received a correspondingly disposed rib, provided upon an adjusting block l, m, which are screw-threaded to engage the sleeve i and the shaft h, respectively. Upon rotation of the sleeve i, the block l is moved axially to advance or withdraw the stop j, and similar rotation of the shaft h adjusts the stop k. Stops may be provided at both edges of the plates. Other plates may be carried by the right-hand half of the cylinder, the clamping and adjusting mechanisms being positioned for operation from the other end and being staggered in position to clear the mechanisms for the plates A, B.