GB1115191A - Improvements in or relating to rotary printing machines - Google Patents

Abstract

1,115,191. Printing-apparatus; feeding sheets. WAITE & SAVILLE Ltd. 18 Jan., 1965 [17 Oct., 1963], No. 41023/63. Headings B6B and B6C. Feeding sheets and cylinder tripping.-Intermittently pulsed photo-electric cells 19, Fig. 1, are used to detect faulty sheet-feed at the front lays 2 of a sheet-feed device 1. If a fault is detected in the sheet-feed the cell is used to de-energize solenoids which maintain the sheetgripping, damping, inking and impression cylinder trips in operational relationship. Fig. 5 (not shown), depicts suitable circuitry. The sheets are transferred from the device 1 by a cylinder 3. The sheets are transferred from the first unit to the second, Fig. 2 (not shown), by three transfer drums, drums 6 and 10 being shown in Fig. 1, and a further photo-electric cell adjacent the third drum (11) controls the electromechanical tripping of the second unit. A cam 22, Fig. 3, closes a switch 21 so as to pulse the photo-cells 19. If a sheet is fed correctly, a switch (58), Fig. 5 (not shown), .remains in a position (NC) and a switch (59) is temporarily closed after the switch 21 to complete a circuit which energizes arelay (A) and a solenoid, 35, Fig. 3. A lever 34 is oscillated, via a lever 31, by a follower 30 engaging a cam 29 and, when the said solenoid 35 is energized, the oscillating lever contacts a follower 38 on a member 40 and raises a rod 42. Lever 47 is then lowered and a surface 77B engages a pin 80 and moves lever 50 connected to the bushings of the impression cylinder to the operative printing position. The lever 50 closes a switch (51). If a sheet is improperly fed or is absent the switch (58) is moved to position (NO) whereby a relay (B) is'energized via the switch (51). The solenoid 35 is then de-energized and the rod 42 lowered so that a surface 77A engages a pin 79 and the lever 50 moves the impression cylinder into the inoperative position and opens the switch (51). Energization of the relay (A) may control the tripping of the sheet-feed arrangement, the damping mechanism, and the inking mechanism, Fig. 4 (not shown). Rotary printing machines.-The sheets are printed in a two-colour rotary offset machine, each stage including an impression roller 4, an offset roller 5, a printing cylinder 7, and damping and inking units 8 and 9.