GB973040A - Mechanism for the transport of printed sheets between two impression cylinders - Google Patents

Abstract

973,040. Rotary offset printing machines; sheet-feed mechanism. COLOR METAL A.G. Oct. 4, 1962 [Oct. 18, 1961], No. 37597/62. Heading B6C. In an endless chain type mechanism for transporting printed sheets from one printing couple to another, positive engagement between each sheet-gripper carrying chain motivated carriage 7, Fig. 1, and the drive of the printing machine-which is directly coupled to the drive of the axles 48, Fig. 5, of chain wheels 8-as the sheets are transferred to or from the transporting mechanism from or to the impression cylinder 3 of the relevant couple is effected through the engagement of rollers 11, 43, Figs. 5, 8, 9, mounted on the carriage, with reversing stirrups 16 provided around the chain wheels. Each stirrup has guideways 57, 58, Fig. 5, the latter having a recessed portion 58a. These guideways respectively engage roller 43 and 11 the recessed portion 58a allowing a period of carriage travel around each wheel 8 during which only the engagement of the roller 43 is effective. This ensures that during the period of sheet transfer action, when the grippers on the carriages and the impression cylinders interact through the usual cam operation, the only drive connection between the machine drive and each carriage is that between wheel mounted support forks 34 and 40, Fig. 5, and respective carriage mounted roller 33 and bolt section 39, Fig. 9. Such connection is effected by the engagement between the guideway 57 and the roller 43 causing the roller 33 and the bolt section 39 to be pressed tightly into the forks 34, 40. The guideway 58 is in effect a continual tion of guide rails 10 provided for carriage guidance between the chain wheels 8 through the interengagement therewith of the rollers 11. The chain drive to each carriage as the latter moves between, the chain wheels 8 is effected by the engagement of a drive roller 64 of a driver member 59, Figs. 8, 9, pivotally mounted on each chain, with a U-shaped link 31 having divergent limbs supported at the associated end of the carriage. This link is disengaged whilst the carriage is passing around each wheel 8 as the roller 64 has moved towards the axle 48 and has consequently come to rest between the limbs of the link 31 where the distance from limb to limb is greater than the diameter of the roller 64. Each carriage 7 is laterally guided through resiliently mounted rollers 47, Fig. 7 (not shown), at each end of the carriage contacting the rails 10. In a modification, Figs. 11, 12, the support fork 40 is replaced by a spring-loaded support arm 86 having a rounded head 85 for engaging a roller 84 mounted on the carriage in lieu of. the bolt section 29. The support fork 34 is replaced by a radially adjustable fork member 70 whilst connection between the carriage and each chain is effected through a resilient strap 75 which replaces the driver member 59, driver roller 64 and link 31.