Patent ID: 6959797

Claim:
A piston-cylinder assembly comprising a cylinder containing a blocking medium, a piston rod which is axially movable in said cylinder, and a piston affixed to said piston rod and dividing said cylinder into two working spaces, said piston comprising at least one flow-through opening connecting said working spaces, a ring groove bounded by axially opposed side walls, and an elastically deformable valve ring seated in said ring groove with axial play, said valve ring frictionally engaging said cylinder, said at least one flow-through opening comprising at least one pocket formed in at least one of said side walls, said at least one pocket being completely open when said piston rod is at rest with respect to said cylinder, said valve ring moving toward one of said side walls as a function of the direction of movement of said piston rod, said valve ring deforming into said at least one pocket to at least partially seal off said at least one pocket when the piston rod exceeds a predetermined speed relative to the cylinder, so that flow of said blocking medium between said working spaces is impeded and said speed is limited.