US Patent 8443948 Vibration damper with stroke-dependent damping force

A vibration damper including a cylinder in which a displacer carries out a translational movement. The displacer has a work piston which divides the cylinder into two work spaces. The work spaces outside the displacer for each operating movement direction of the displacer are connected to damping valves by a flow connection. Every flow connection has only one flow direction through a check valve arrangement. The flow connection has a plurality of inflow ports which are offset in axial direction starting from the work spaces and is formed by a bypass channel, and a plurality of damping valves are connected to the bypass channel and admit damping medium via the inflow ports.