GB1173610A - Improvements in and relating to an Offset Printing Machine. - Google Patents

Abstract

1,173,610. Offset press. RICOH K.K. 29 Dec., 1966 [30 Dec., 1965; 2 Dec.. 1966], No. 58034/66. Heading B6C. An offset printing machine comprises an impression cylinder which is provided with a clamping mechanism for retaining the leading edges for copy sheets and a feeler pin which is movable radially, the arrangement being such that, if the clamping mechanism fails to retain the leading edge of a copy sheet, the pin is moved from a position within the circumference of the impression cylinder to a position where it extends beyond the periphery and operates means to disengage the blanket cylinder from the impression cylinder. General arrangement.-Copy sheets 33 are fed by means of friction rollers 30 carried on an oscillating plate (29) (Fig. 3, not shown) to the clamping fingers 50, Fig. 7, of an impression cylinder 4 which forms part of an offset press further comprising a plate cylinder 2 and a blanket cylinder 3. The drive for the oscillating plate (29) is a cam 42 on the impression cylinder 2. A further cam 15 also mounted on the impression cylinder shaft 4a causes a lever 6. to oscillate under the action of cam roller 13 and link 12. The lever 6 is connected to, a bearing which is eccentric to blanket cylinder shaft .5, and the blanket cylinder is tripped when a portion 16a of stop 16 engages shoulder 6c on lever 6. Sheet detectors.-A longitudinal recess 48, Fig. 7, for the clamping fingers 50 of the impression cylinder also contains feeler pins 63 corresponding in number to the clamping fingers and reciprocating under the action of a further cam (59) (Fig. 13, not shown) on the impression cylinder shaft 4a. If the pins project beyond the periphery of the cylinder, e.g. when a copy sheet is absent, they engage corresponding pins (76) (Fig. 5, not shown) acting on stop lever 16, thus engaging the latter with lever 6.