Throw-off system for rotary offset printing press

US4000692A · kind A · utility

Assignee

• Roland Offsetmaschinenfabrik Faber & Schleicher AG

Inventors

• Burkhardt Wirz · Munich, DE
• Peter Decker · Marl, DE
• Valentin Gensheimer · Frankfurt am Main, DE
• Alfred Dorn · Mühlheim, DE

Key dates

• Filing date: Dec 1, 1975
• Grant date: Jan 4, 1977
• Expiry date: Dec 1, 1995

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B41F33/0054
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A system for facilitating throw-off and re-engagement of a blanket cylinder with respect to cooperating plate and impression cylinders and which minimizes wastage of copies incident to reestablishing equilibrium in the inking and dampening systems following an interruption of the normal printing process. Two separate control means are provided for controlling the rate of water flow, the first being an automatic control at the water fountain and the second being in the form of means for controllably disengaging the water form roller from the printing plate. Means are provided for switching from the first control means to the second when the blanket is disengaged for promptly cutting off the flow and thereafter maintaining a water film of predetermined thickness on the plate. Simultaneously with disengagement of the blanket cylinder the ink feed rolls are declutched and the ink form rollers are disengaged for promptly cutting off flow of ink to the plate while preserving the film thickness gradient which exists in the ink feed system. A blanket cleaner is incorporated together with means for spraying solvent on the ink feed rolls. The throw-off mechanism is so arranged that, upon res…