GB767782A - "improvements in and relating to automatic platen printing presses" - Google Patents

Abstract

767,782. Printing presses. SCHNELLPRESSENFABRIK AKT.-GES HEIDELBERG. Nov. 22, 1954 [Dec. 30, 1953], No. 33667/54. Class 100(2) In an automatic platen printing press wherein the impression movement is obtained by a crank and connecting rod 5 operating toggle levers 4 pivoted to a shaft 6 displaceable for switching the printing pressure on and off while the machine continues to run, either the shaft 6, or its eccentric bearing 7, or the device 8, 9 by which it is displaced, is connected with the inking mechanism drive or with individual ink transfer rollers by means of a connecting rod 11, whereby the ink supply is interrupted when the printing pressure is tripped The rod 11 links a pin on the bearing 7 to a collar 23 on one arm 12 of a bell-crank lever, the other arm 18 of which lies idle as shown during normal printing: when the printing pressure is switched off by lifting and pushing in the member 9, the rod 11 is raised and the arm 18 moves into the path of an arm 17 projecting from the swinging mounting of the messenger roller 16 whereby the latter is prevented from contacting the fountain roller 20. To enable ink to be supplied even when the printing pressure is tripped, e.g. for initial inking-up, the arm 18 may be manually moved clear of the arm 17 against a spring 14 on the rod 11; the bellcrank lever 12, 18 is held in this position by lifting a catch (not shown) pivoted to the collar 23 until it engages a fixed stop; when the printing pressure is again switched on, a stop 27 on the rod 11 lowers the arm 12 sufficiently to enable the catch to fall away from the fixed stup, whereby the mechanism is ready to interrupt the ink supply when the printing pressure is next tripped. In a modification the upward movement of the member 9, as the arm 8 swings to the'right, is used to lift the rod 11: two arms are fixed to a rotatable shaft, one carrying a roller which rides on the top of the member 9 and the other being pivoted to the rod 11; also the catch for holding the arm 12 down hangs from a fixed pivot and may be swung into engagement with a projection on the arm. In a further modification, the bell-crank lever 12, 18 is replaced by a straight twoarmed lever linked to the swinging mounting of one of the rollers of the ink train whereby the roller is withdrawn from the train when the printing pressure is tripped.