Double-tube vibration damper

US4821850A · kind A · utility

Assignee

• Fichtel & Sachs · DE

Inventors

• Wolfgang Geiling · Schweinfurt, DE
• Felix Wossner

Key dates

• Filing date: Mar 27, 1987
• Grant date: Apr 18, 1989
• Expiry date: Mar 27, 2007

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/7849
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

For a double-tube vibration damper which comprises an axially proceeding groove in the cylinder for by-passing the piston valves, a piston is provided which possesses a satisfactory sealing and guidance function in the cylinder. This is achieved in that the piston comprises a rigid piston ring arranged in a piston groove and acting as sealing ring against the cylindrical surface, while the piston comprises a second piston ring groove for the reception of a guide ring consisting of a piston ferrule. In this case at least one relief passage is provided which connects the second piston ring groove and/or the space situated between the piston ring grooves with the working chamber remote from the piston rod.