Arrangement for adjusting the damping force of a shock absorber

A hydraulic telescopic shock absorber having a cylinder closed by a cylinder cap and filled with a damping medium in which a piston having a piston head and a piston rod is reciprocatingly arranged, said piston head dividing the cylinder into two portions and further provided with a plurality of longitudinally extending and circumferentially spaced passages extending therethrough, the passage openings on the lower surface of the piston head being closed by a ring-shaped resilient valve, a rigid pie-shaped closing member coaxially and movably mounted about the piston rod on the upper surface of the piston head, said closing member including a longitudinally extending adjustment tab which engages an adjustment pin fixedly mounted to the lower surface of said cylinder cap, and wherein said passages are selectively opened or closed by extending the piston rod until said pin engages said tab and thereafter rotating the piston rod to expose the desired number of passages.