US Patent 7886882 Pneumatic spring damper unit

Disclosed is a gas spring/damper unit (1) having at least one movably mounted displacement piston (2) and two displacement chambers (3, 4) whose volume increases or diminishes according to the direction of travel of the displacement piston (2) and which are interconnected via overflow ducts (6, 7) in which throttle valves (16, 16′, 16″, 17, 17′, 17″, 17″′) are disposed. Several throttle valves (16, 16′, 16″, 17, 17′, 17″, 17″′) having different valve characteristics are positioned so as to be effective in one direction of flow. One throttle valve (17) is designed for damping eigenfrequencies ranging from 1 to 1.5 Hz while another throttle valve (17′) is designed for damping eigenfrequencies ranging from 10 to 40 Hz.