GB434422A - Improvements relating to printing presses - Google Patents

Abstract

434,422. Printing-machines. HAWARD, E. W., 2, Tudor Mansions, Church Road, Hendon, and HAWARD GRAVURE MACHINE CO., Ltd., 1, Broad Street Place, Blomfield Street, both in London. Feb. 27, 1934, No. 6378. [Class 100 (ii)] Gripper mechanism.-In connection with rotary printing-presses in which the impression cylinder a is moved to and from the printing - cylinder between successive impressions, the grippers are constructed, so as to be capable of dealing with sheets of different thicknesses, of spring- controlled members b, coacting with a gripper bar e which is spring- mounted and is capable of being withdrawn into the cylinder a as the grippers move past the printing-cylinder. The bar e extends laterally beyond the periphery of the cylinder a and is formed with cam surfaces extending a slight distance radially beyond this periphery, and at the commencement of the printing operation the surfaces j engage cam surfaces on the printing-cylinder or the machine frame in order to withdraw the grippers into the gap in the cylinder a to prevent the fouling of the grippers with the printing-surface of the printing-cylinder. In Fig. 2 the bar e is pressed outwards by a spring i and it is formed with an enlarged head f which has a limited play in a recess g formed in part by a recess in the rear end wall of the gap in the cylinder and in part by a recessed guide member h secured by bolts to the bottom of the gap. In a modification, Fig. 4, the bar e is guided by a plate m secured to the rear end wall of the cylinder gap by screws n which pass through slots in the bar e. The grippers b close under the action of extension springs d, Fig. 2, or a torsion spring o, Fig. 4.