Patent ID: 7172057

Claim:
A vibration damper comprising: a cylinder filled with damping medium; a piston rod which is movable axially in said cylinder, said piston rod carrying a piston which divides said cylinder into two working spaces; a housing in one of said two working spaces, said housing having a chamber separated from said one of said working spaces by a separating element which is stationary with respect to said piston rod, said housing being movable with respect to said piston rod so that said chamber has a volume which is variable within defined limits, and wherein said housing comprises a bottom and a sleeve part forming a cup which cooperates with said separating element to form said chamber, the volume of said chamber varying independently of the direction of movement of the piston rod; a pair of restoring spring elements acting between said housing and said piston rod, each said restoring spring element corresponding to a respective direction of movement of said housing with respect to said piston rod; and a flow connection connecting the other one of said working spaces to said chamber.