Piston-cylinder unit particularly for an extrusion cartridge

US4197967A · kind A · utility

Assignees

• Denso-Chemie Wedekind KG · DE
• Peter Lancier Maschinebau-Hafenhutte Gmbh & Co. KG · DE

Inventors

• Fritz Baur · Panketal, DE
• Gunther Stemmer · Ennigerloh, DE

Key dates

• Filing date: Aug 9, 1978
• Grant date: Apr 15, 1980
• Expiry date: Aug 9, 1998

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B05C17/00576
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A piston-cylinder unit includes a cylinder having an inner cylindrical wall face; a pressure piston slidably accommodated in the cylinder and arranged for being driven into the cylinder by an external force. The cylinder defines a cylinder chamber in which pressure is generated by the pressure piston forced into the cylinder. The pressure piston has a radial bottom and a generally cylindrical outer face extending axially away from the piston bottom. In the outer face of the pressure piston, adjacent the bottom, there is provided a circumferential recess which, together with an overlying circumferential portion of the inner cylindrical wall face of the cylinder defines an annular chamber surrounding the pressure piston. The radially measured width of the annular chamber gradually decreases in a direction axially away from the piston bottom. A sealing ring is disposed in the annular chamber and sealingly engages the inner face of the cylinder even when situated in the widest zone of the annular chamber. The sealing ring can be shifted and compressed into zones of lesser width of the annular chamber upon displacement of the pressure piston into the cylinder.