Patent ID: 6272986
Filing Date: 2001-08-14
Classification: B41F

Abstract:
An impression cylinder printing apparatus which combines lithographic and flexographic printing on a substrate passing over the impression cylinder of a lithographic printing station in a one pass printing operation, comprising:an offset lithographic printing press having a plurality of successive offset lithographic printing stations having an impression cylinder and a substrate path whereby a substrate is supported for printing on the impression cylinder;a retraction mechanism mounted on any printing station of the press and a flexographic printing head coupled to the retraction mechanism for movement between a storage position and an operating position of the printing head;the printing head comprising a plate cylinder having a printing surface thereon mounted in a frame in operative combination with a roller mechanism and an ink supply for applying a controlled layer of printing liquid to the printing surface, the printing head having an encoder controlled motor driving the plate cylinder of the printing head in registration with the impression cylinder; andapparatus for moving the plate cylinder of the printing head when in the operating position from an off impression condition to an on impression position with a substrate being supported on the impression cylinder of the printing station;whereby a substrate moving across the impression cylinder at the printing station on which the printing head is located can be lithographically printed by the printing station and be flexographically printed by transferring a film of printing liquid from the printing surface to the substrate while it is still on the impression cylinder of the lithographic printing station.