GB253283A - Improvements in rotary duplicating machines - Google Patents

Abstract

253,283. Ramdor, L., and Deutsche Post - und Eisenbahn - Verkehrswesen Akt.-Ges. (Dapagtfubag). April 9, 1925. Stencilling; stopping and tripping arrangements.-A rotary stencil or type duplicator is constructed so as to lock the printing-cylinder automatically if a sheet is not fed or is fed too late, and the printing-cylinder is prevented from moving backwards beyond the permissible point by a pawl which engages a notch in the cylinder, so that impressions cannot be printed unless the sheet is present. The sheets are fed by rollers a, b, the roller b being lowered by a lever and cam d on the printing-cylinder to feed the sheets to the machine. A feeler f rises from a groove in the roller a when a cam l permits, and, if no sheet is being fed, a pawl g is raised by a spring q and engages a ratchet wheel h, which is connected to the printing-cylinder by an elastic connection i or by springs k. The cylinder is thus prevented from rotation by the pawl g, or, if desired, a brake may replace this pawl. The pawl 9 is connected by a link p to a lever arm f<1> on the shaft of the feeler f. When the rollers a, b are apart, the pawl g is held depressed by a lever arm n, which is operated by the cam l to release a pin o on the arm f<1> from the restraining action of the lever n. If the spring q fails to raise the pawl g, it is raised by the action of the lever n on the pin o. The impression cylinder is mounted in eccentric bearings fitted with a ring r for operating them, and provided with a spring catch to hold the bearings in operative or inoperative position. When the ring r is moved counterclockwise to trip the impression cylinder for inking-up purposes, a lug p on the ring r engages the pin o and so prevents the pawl g from locking the printing-cylinder as it rotates to allow inking of the stencil &c.