Universal master cylinder for offset presses

Abstract

A master cylinder for an offset or the like printing press includes an arcuate master receiving surface extension section mounted on the cylinder for movement between an inoperative position into the interior of the cylinder and an operative position adjacent the tail end of the stationary master receiving surface of the cylinder. When in the operative position the extension section increases the length of the master sheet receiving surface of the cylinder to accommodate longer than 'standard' length master sheets. The extension section is mounted for sliding movement on arcuate guides formed by the movement of a predetermined radius extending from a point off center with respect to the central axis of the cylinder. A locking assembly is included to secure the section in either position. A tail clamp for longer masters is provided on the free end of the extension section. The standard tail clamp is also mounted for movement from an inoperative position adjacent the tail end of the stationary master receiving surface of the cylinder to a position within the cylinder to permit movement of the extension section to an operative position. In a preferred embodiment, a pivotal assembly within the cylinder is coupled both to the extension section and the standard tail clamp to move the latter into an inoperative position simultaneously with the movement of the extension section to an operative position and vice versa.