Patent GB-823552-A (GB)
Title: Improvements in or relating to duplicating machines
IPC: B41L21/10
Filed: 1956-04-20
Abstract: 823,552. Duplicating-machines; feeding and delivering sheets. RITZERFELD, W., and RITZERFELD, G. April 20, 1956 [April 23, 1955], No. 12123/56. Classes. 100(1) and 100(2) A rotary duplicating machine for directly printing from a mirrorscript master sheet attached to a printing drum comprises a counter pressure roller co-operating with the drum and conveyer means to guide a copy sheet from a feeding point through the printing position to a delivery point, the conveyer means having a copy sheet gripping bridge extending between movable guides, the guides and bridge performing one circuit during each revolution of the drum. The drum 1, Figs. 1, 9 and 14, is driven by a motor 6 and is connected to an elemental toothed wheel 23 by a onerevolution clutch 45. The guides are chains 13 running on chain wheels 14 keyed to a shaft 18, 15 idle on the ends of the counter pressure roller 4 and 16 keyed to a delivery roller 19, Figs. 1, 9 and 10. The counter pressure roller 4 is mounted on an eccentric shaft 5 carrying a lever 55. When the lever 55 is moved clockwise by a hand or foot control, it moves the roller 4 into contact with the drum, rotates the eccentric shaft 62 of the roller 19 to keep the chains uniformly tensioned and releases a lever 46, whereupon a spring 57, through a pin 49 on the lever and or slot in a slide 50 moves the latter into a recess 58 of a ring 59 rotating with the drum as soon as the recess and slide are in alignment, thus coupling the drum to the wheel 23, on which the lever 46 is pivoted and driving the chains 13 through an elemental toothed wheel 22 and toothed wheels 21, 20. Before the drum completes its revolution, the lever 55 is returned to the position of Fig. 9, re-engages the lever 46 when the revolution is completed, and so releases the wheel 23, which is stopped by a pawl 53 engaging an end of the slide 50. The gripping bridge 17, Figs. 1, 3, 5 and 6, comprises a body 27 carrying a shaft 28 on which are pivoted grippers 29,. a sheet-sensing device 30, and ejecting. levers 31 connected by an ejecting bar 34 all urged by springs clockwise in Figs. 5. and 6, the grippers and sensing device resting on a sheet and the bar 34 underlying the sheet. In the initial position I, Fig. 14, of the bridge, cam-actuated levers 81, Fig. 1, engage curved parts 29a of the grippers and hold them open for introduction of a sheet. When the bridge reaches the delivery roller 19 Fig. 10, a cam 37 on the bridge raises presser rollers 64 off the roller 19 to allow the bridge to pass, whereupon curved portions 29a, 31a of the grippers ,and ejecting levers respectively are engaged by blocks 69 on a rod 70 carried by levers 68, whereby the grippers are opened and the bar 34 moved to eject the sheet. If there is no copysheet in the bridge, the sensing device 30 moves downwards, a curved portion 30a thereof moving upwards so as to engage a lever 72 when the bridge reaches position II, Fig. 14, and operate a contact 74 to energize an electro-magnet 75, which attracts a lever 77 to release a lever 79 keyed to the shaft 5, whereupon a spring 80 ,rotates the shaft counter-clockwise to move the roller 4 away from the drum, whereupon the bridge moves past the printing and delivery positions into position I, when the clutch 45 is disengaged by the lever 55.