Pneumatic spring-damper unit

The pneumatic spring damper unit (1) has a spring chamber formed through a U-bellows (3), and damping chambers (10,11) accommodated inside a cylindrical housing (2) in which is installed a piston (4) with valves or restrictors. An additional auxiliary chamber (12) with a constant gas volume is connected to one (11) of the damping chambers and these chambers intercommunicate through restricting orifices and/or throttle valves (14,15) which are formed in a plate (13) which separates the damping chamber and auxiliary chamber.