REVERSIBLE LOCKUP FOR FLEXIBLE PRINTING PLATE

摘要

A lockup for securing a flexible printing plate to a reversibly driven plate cylinder in which the leading end of the plate may be held in a reference position and in which the trailing end of the plate may be kept under constant tension regardless of the direction of cylinder rotation. A longitudinal groove is formed in the cylinder having undercut edges with a rockable shaft being mounted in the groove having a gripper extending longitudinally of the shaft and presenting gripping edges facing in opposite directions. An overcenter spring toggle detents the shaft in two positions in which the gripper lies on one side or the other of the center of the groove, manual throw-over means being provided for throwing the shaft between its detented positions so that, when a first end of the plate is hooked over one of the undercut edges and the second end of the plate is placed in the path of movement of the gripper, manual throw-over causes the gripper to swing into gripping engagement with the second end of the plate to keep the plate under constant tension on the cylinder. In the preferred embodiment the gripper is in the form of a leaf spring partially recessed in the shaft and symmetrical stops are provided for limiting rocking movement of the shaft in both directions.