GB1345914A - Printing machines having control apparatus - Google Patents

Abstract

1345914 Printing apparatus MATHIAS BAUERLE GmbH 19 April 1971 [5 March 1970] 23443/71 Heading B6C A control device for sequentially operating the elements of a rotary offset lithographic printing machine comprises a shaft 1 carrying a series of control cams 2-8, a toothed switch wheel 27 fixed to the shaft and an actuating pawl 29 oscillatible in synchronism with the machine drive and arranged to be brought into engagement with the wheel 27 under the control of a solenoid 50. The teeth of the wheel 27 are profiled such that the pawl, when engaged with the wheel perform a predetermined number of control switching steps before becoming automatically disengaged. The cams 2-8 are arranged to control the main motor switch, the paper feed, the plate cylinder trip, the etching apparatus trip, the inking and damping apparatus trip and the blanket washing apparatus trip respectively. The functioning of each of these cams is brought about by a corresponding indexing movement of the wheel 27. A manually operable knob 15 is used to sequentially set all of the machine functions in operation. In response to the detection of a low paper supply at the feed board the solenoid 50 is actuated and a locking disc 23 is moved (by lever 48) to permit the pawl 29 (oscillated by a cam mounted on the shaft of the blanket cylinder) to engage the switch wheel 27 and index the wheel until the configuration of a tooth causes the pawl to rise sufficiently for the locking disc 23 to re-engage. At this stage the paper feed is stopped and the blanket cylinder is tripped out. After re-load of paper the mechanism may be manually re-set to print. In response to brief depression of a manual push button the solenoid is actuated to set the machine in the tripped condition discussed above. Further depression of the button causes tripping out of the inking apparatus after which the tooth profile causes the pawl to be again rendered inoperative. Further depression brings the machine to a condition where only the blanket washing apparatus is operative and after a predetermined number of washing cycles the solenoid is automatically operated to switch off the machine. After printing of a predetermined number of copies as determined by a sheet counter the solenoid is actuated to cause the machine to be set for the blanket wash condition and then to shut down. In an alternative embodiment, switching on of the various machine elements may be controlled by a further switch pawl.