Patent ID: 7523818
Filing Date: 2009-04-28
Classification: F16F

Abstract:
1. A vibration damper with amplitude-selective damping force, the damper comprising: a cylinder containing a damping medium; a piston rod which is axially movable in said cylinder; a piston assembly arranged for axial movement in the damping medium, the piston assembly being connected to the piston rod and dividing the cylinder into a working space around the piston rod and a working space opposite the piston rod, the piston assembly comprising a piston body having connecting channels for opposite directions of flow between the working spaces, and valve disks which open the channels in respective said opposite directions; a flow connection between the working spaces; an axially movable throttle ring which determines at least one first pilot cross-section in the flow connection as a function of movement of the piston rod, and a pair of first stop surfaces which limit axial movement of the throttle ring; and a pilot assembly comprising an axially movable shifting ring which determines at least one second pilot cross-section in the flow connection as a function of movement of the piston rod, and a pair of second stop surfaces which limit axial movement of the shifting ring, wherein the second stop surfaces are independent of the piston body and the valve disks, wherein the at least one first pilot cross-section is larger than the at least one second pilot cross-section.