GB234492A - Improvements in rotary duplicating machines provided with automatic sheet-feeding devices - Google Patents

Abstract

234,492. Le Grand, R. P. A., and Garret, A. M. May 21, 1924, [Convention date]. Stencilling; rotary machines; gripper mechanism.- Sheets are fed to a rotary duplicator employing a stencil, type, or a lithographic printing plate by means of a suction device operated by the printing cylinder, the impression cylinder being tripped when no sheet it fed. A counter may be simultaneously disconnected. The machine comprises an impression cylinder 31 and a printing drum C, the latter being mounted in bearings in side frames 1, 2 and rotated by a hand crank M provided with means to prevent reverse rotation. Sheets are placed on an inclined support 65 with their edges resting against a bar 66 carried by adjustable arms 67. Fixed within the drum C is a tube 8 provided with perforations 9 - - 11 and connected to a suction cylinder 12, the plunger P of which is raised by a pivoted lever L and is depressed by a spring 15. The lever L is oscillated by a stationary but angularly adjustable snail cam 18 engaging its outer end E; or it may be actuated manually when the machine is stopped. The tube 8 communicates with the cylinder 12 through an automatic valve which is closed by the upward movement of the piston and prevents any action on the sheets while they are being fed. The sheets are stripped from the drum C by prongs 69, 70 pivoted to a cross bar 71 and are directed into a receiver 72. Tripping-arrangements.-The impression cylinder 31 is mounted on a shaft 24 pressed towards the drum C by rods 26, 27 acted on by springs. When no sheet is present the plunger P falls to the bottom of the cylinder 12, and the end E of the lever L strikes against a rocker 33 linked to cams which engage lugs 38, 39 on the shaft 24 and so raise the impression cylinder into a position where it is held by catches 40, 41. Claws 42 fixed on the drum subsequently engage the lugs 38, 39 and return the sylinder io normal position.