GB756225A - Improvements in plate-holding arrangements for use on printing machines - Google Patents

Abstract

756,225. Printing plates. CRABTREE & SONS, Ltd., R. W. Feb. 24, 1954 [Nov. 24, 1952], No. 29634/52. Class 100 (2). A printing plate is bent over at each end to form a flange 2, Fig. 3, having an inturned lip 3, the plate being strained round the circumference of a cylinder by pressure bars 5 received in slots in the circumference of the cylinder and having surfaces 6 to bear against the inside faces of the flanges 2, and slots 4 to receive the lips 3. The pressure bars extend longitudinally of the cylinder and may have locking pins 9 adapted to pass through openings in the lips 3 to secure the ends of the plate. These pins have transverse portions 10 by means of which they are projected and withdrawn for removal or attachment of the plate to the bars. The bars may be forced together by radial screw-threaded means as described in Specification 642,958 in which case slots 12, Fig. 2, are cut in the bars, and corresponding gaps provided in the flanges 2 to allow insertion of a tool for rotating the screw. In the form of Fig. 5, however, the necessity for slots and gaps is avoided by using clamping screws 14 rotatably secured at 18 in the side walls of the slot 7 and arranged alternately, each being threadedly engaged in a clamp member 16. The members 16 are also arranged alternately along the length of the slot 7 slidable in guides 17 and adapted to bear on one or the other of the pressure bars 5. The screws 14 are actuated to strain the printing plate by a thin plate spanner 20 inserted between the ends of the plate and engageable with flattened ends 19. Alternatively only one pressure bar may be provided, the other end of the printing plate being engaged with a suitably formed wall of the slot 7. More than one slot is provided where the printing plate does not extend round the whole circumference of the cylinder.