DEVICE FOR MOVING THE IMPRESSION CYLINDER OF A PRINTING PRESS INTO AND OUT OF PRINTING ENGAGEMENT WITH AN IMAGE CARRIER CYLINDER

摘要

A printing press having an impression cylinder with a bearing at each end an image carrier cylinder and a frame in which both cylinders are positioned. A device is provided for moving the impression cylinder between an engaged printing position cooperating with the image carrier cylinder and a disengaged position and also for producing a larger motion of the impression cylinder for the purpose of replacing the image carrier cylinder. A lead screw is provided for each bearing for lifting and lowering the bearing of the impression cylinder and a thrust piston and cylinder unit for acting on each bearing for urging the impression cylinder towards the image carrier cylinder. A nut engages each lead screw, each nut having a tubular section with a constant external diameter, and a pinion is mounted on each tubular section, and having a hub supported for pinion rotation in a fixed position relative to the frame. The pinion is rotatively locked to the tubular section for rotation and for sliding to a limited extent for maintaining the pinion in mesh with gearing for rotatively driving the pinion during the large motion. Each bearing is compensated by balance the weight of the bearing of parts connected with the bearing and of the impression cylinder.