Oscillating sheet gripper drive - has hydraulic control unit linked to oscillating gripper shaft for rotary printingmmachine

摘要

The control circuit has a setting indicator which interacts with a cam disc, an actual-value indicator operated by the piston rod whereby the two indicators are connected to an actual-desired-value differentiator in the form of a variable gain amplifier. The difference recorded is used to control a servo-valve for the printing ink supplied to the piston. The two indicators are constructed as potentiometers. The servo-valve is a four-three way valve. The actual-desired-value difference is adapted to different machine speeds by means of a centrifugal governor. The design is intended to reduce oscillations and eliminate double impressions during printing.