Abstract: A shock-absorber includes a cylinder and a piston arranged within the cylinder and provided with at least one passageway of variable area for controlling flow of a working fluid from one side of the piston to the other side thereof. A controllable device is incorporated within the piston and continuously controlled by external control signals from a control unit to vary the area of the passageway. The external control signals are supplied by the control unit in response to input signals received from sensors which are associated with the shock-absorber. The input signals are related to the instantaneous parameter information obtained from the piston. The value of the external control signals varies during the stroke of the piston at least in part as a function of the input signals.

Abstract: A shock absorber works with a variable element (15) which determines the size of a medium passage between the upper and lower sides of a piston (10) in the absorber. The element is arranged so that, with the help of the inertia of its mass, it can carry out a relative displacement movement in its bearing when an acceleration force acts on the mass as a result of the acceleration of the object. The element (15), responsive to the displacement movement, exerts influence on the size of the medium passage.