Piston-cylinder aggregate with displacement-dependent dampening force field

US5971117A · kind A · utility

Assignee

• Fichtel & Sachs · DE

Inventors

• Manfred Grundei · Niederwerrn, DE
• Hans Reimer · Waigolshausen, DE
• Harald Holzapfel · Schweinfurt, DE

Key dates

• Filing date: May 6, 1997
• Grant date: Oct 26, 1999
• Expiry date: May 6, 2017

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16F2230/42
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A piston-cylinder aggregate comprising a cylinder in which an axially movable piston rod is arranged is provided. The piston rod has two pistons, which are separated from each other and which produce a damping force of a variable magnitude depending on the piston rod's stroke position. The piston-cylinder aggregate has a bypass area defined in its inner wall along a portion of the length of the cylinder, so that the damping force is at least reduced in the stroke area of the bypass, and the two pistons have a separation equal to or less than the length of the bypass, such that depending on the position of the piston rod, a damping force of variable magnitude is produced. For example, when both pistons are disposed within a section of the cylinder defined by the bypass area, the dampening force exerted by the piston rod is minimized, while when both pistons are outside the bypass area, the dampening force in both stroke directions is maximized.