Dampening unit for an offset printing machine

US5992317A · kind A · utility

Assignee

• MAN Roland Druckmaschinen AG · DE

Inventors

• Peter Hummel · Offenbach, DE
• Robert Ortner · Alzenau, DE
• Rudolf Raab · Hanau, DE

Key dates

• Filing date: Apr 17, 1998
• Grant date: Nov 30, 1999
• Expiry date: Apr 17, 2018

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B41F7/26
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

An offset printing machine having a plate cylinder which carries a printing form and which is operatively connected to an inking unit and a dampening unit is provided. The dampening unit includes a dampening applicator roller which is mounted in contacting relation with the dampening applicator roller. The dampening applicator roller also includes at least one auxiliary roller which is mounted in contacting relation with the dampening applicator roller downstream or after the contact point between the dampening applicator roller and the plate cylinder. The auxiliary roller has a surface with a coating of non-stick material which blocks the transfer of ink and dampening medium to the surface of the auxiliary roller and is axially movable relative to the dampening applicator roller and selectively rotatable at circumferential speeds substantially equal to or different from the circumferential speed of the dampening applicator roller.