摘要 |
1468554 Offset printing press; replacing cylinders CHAMBON Ltd 24 Oct 1974 [24 Oct 1973] 46014/74 Heading B6C An offset printing press comprises an engraved or plate cylinder 2 mounted on the main frame 1, a blanket cylinder 4 and an impression cylinder 8 mounted on a subsidiary frame composed of horizontally-movable side plates 7 and screw assemblies which on rotation of a hand wheel, Fig. 2 (not shown), first release the pressure between cylinders 2 and 4 and then move cylinders 4 and 8 on frame 7 away from cylinder 2 to allow for replacement with differently-sized plate and offset cylinders. The screw assembly includes transverse shaft 19, worm gear 18, 15, compressible washers 17 and screw-threaded rods 13. The washers 17 exert a restoring force during the first revolution of the hand wheel but subsequently, after they have been completely expanded, the hand wheel causes direct movement of the side plates 7. The impression cylinder is pivoted on two-armed lever 10 at point 11, the pressure adjustment being by button 34; on movement of the subsidiary frame, the cylinder 8 is tripped from cylinder 4, but is restored at the same pressure on return of the frame. |