Abstract: A vibration damper for damping spring retraction and extension forces on vehicles includes an inner pressure medium cylinder, in which a piston with a piston rod is axially slidably arranged to divide the inner cylinder into a retraction chamber and an extension chamber in which an electrorheological fluid is contained as a pressure medium. The two chambers are connected through at least one throttle gap between the inner cylinder and an electrode tube arranged coaxially thereto. The electrode tube is surrounded coaxially by an outer tube which forms a gas pressure chamber connected with the retraction chamber through a bottom valve. Axially linear or helical seals are arranged between the inner cylinder and the electrode tube, and divide the throttle gap into at least two valve partial gaps. A throttled non-return valve opens toward the gas pressure chamber between the extension chamber and the gas pressure chamber.

Abstract: The invention relates to a vibration damper for damping spring retraction and/or spring extension forces on motor vehicles, which includes an inner pressure medium cylinder (1), in which a piston (2) with a piston rod (3) is axially slidably arranged, which divides the inner pressure medium cylinder (1) into a retraction chamber (4) and an extension chamber (5), in which an electrorheological fluid as a pressure medium is contained, wherein the retraction chamber (4) and the extension chamber (5) is connected through at least one throttle gap (6) between the inner cylinder tube (1) and an electrode tube (7) arranged coaxially thereto, and that the electrode tube (7) is surrounded coaxially by a spaced-apart further outer tube (8), which together with the electrode tube (7) forms a gas pressure chamber (9), which is connected through a bottom valve (10) with the retraction chamber (4).