GB691994A - Improved multi-colour sheet printing machine - Google Patents

Abstract

691,994. Printing-machines. FABER & SCHLEICHER AKT.-GES. Feb. 1, 1951 [Feb 15, 1950], No. 2522/51. Class 100(ii) A multi-colour sheet printing-machine comprises several printing units disposed one after another and driven by a main group drive, each unit being provided with an auxiliary drive and with means for coupling it thereto when it is disengaged from the main drive. Two two-colour five-cylinder offset presses 1, 2 are shown in Fig. 1; sheets are transferred from one impression cylinder 3 to the other by a take-off roller 8 connected to a feed roller 10 by chains 9 equipped with grabs and carriages. A main driving pulley 13 is driven by a belt &c. from an electric motor 11, Fig. 2, and an auxiliary driving pulley 23 is similarly driven from a motor 25. The pulley 13 is secured to a shaft 14 which transmits the drive through bevel gears 15, 16 to the press 2; a double clutch member 20, slidably keyed to a shaft 17, in one position engages with its single tooth 21 a recess in the side of the pulley 13 to transmit the main drive through bevel gears 18, 19 to the press 1; in its other position its cone 22 engages the pulley 23, normally loose on the shaft 17, to transmit the auxiliary drive to the press 1. The clutch is operated by a hand lever 27 on a shaft 26 connected thereto through a link 29 and bell-crank 30; when the member 20 engages the pulley 13 a lever 42 on the shaft 26 operates a switch 40 to complete the circuit of the main driving motor 11 for normal running, and when it engages the pulley 23 the lever 42 operates a switch 39 to complete the circuit of the auxiliary motor 25 and to connect the motor 11 for slow running; intermediately both motors are switched off. A separate control may be provided to connect the motor 11 for slow running when the member 20 and pulley 13 are engaged. The take-off and feed rollers 8, 10 are coupled to their respective presses by single-tooth clutches operated from the shaft 26 by an arm 43 and a bell-crank 35 respectively, the arrangement being such that these clutches engage after, and disengage before, the member 20 and pulley 13; they each comprise, Fig. 2, a slidable part 32 keyed to the respective roller shaft 31, and a part 33 rigid with the driving gear 31a free on the shaft 31; disengagement is prevented by a fixed lug 37 which engages the side of the operating groove of the part 32 except where there is a recess 36 located to correspond to a position of the chain grabs out of range of the impression cylinders 3.