GB255203A - Improvements in and relating to lithographic printing machines - Google Patents

Abstract

255,203. Wright, F. W., and Mann & Co., Ltd., G. June 11, 1925. Damping-apparatus for lithographic machines. -In a lithographic printing-machine in which the forme-damping roller or rollers automatically receives a cyclic movement into and out of contact with the plate cylinder, the damping-rollers are mounted on a bracket which is normally stationary but is movable when desired to carry the rollers into an inoperative position. Fig. 1 shows a plate cylinder B provided with two sets of damping-apparatus mounted on brackets a, a<1> pivoted upon shafts b, b<1> but normally held stationary by toggle-link mechanism c, d, c<1>, d<1> actuated by hand levers f, f<1>. Each apparatus comprises two forme-damping rollers 2, Fig. 3, carried by socket members 6 pivoted about the axis of a rider roller 3. Screws 7 and lock nuts 8 are provided to adjust the pressure of the rollers 2 on the roller 3. The sockets 6 are adjustable angularly by screws 14 carried thereby engaging stops 15 and are locked in adjusted position by screws 10 passing through slots 11 in the sockets and screwing into a pair of back plates 9 also pivoted about the axis of the roller 3. The rollers 2 are cyclically moved away from the plate cylinder B about the roller 3 by blocks 17 sliding in slots 16 in the plates 9 and carried by a lever 18 pivoted at 19 to the frame a and actuated by a cam 20 driven by gearing 22 from a gear 23 on the shaft b. The rollers may be kept in continuous contact with the plate cylinder by turning a latch 25 so that a pin 26 engages a lug 27 and prevents the lever 18 from following the cam 20.