Twin-pipe shock absorber

Abstract

A twin-pipe shock absorber comprises a working cylinder (1), a piston (4) which is movable in the cylinder and has a passage and upstream valve (13, 14, 15), and external pipe (2) which is fitted around the working cylinder having an oil tank (3) formed therebetween, a disc (7) having a passage (16) and an upstream valve (17) positioned near the passage to shut off the working cylinder, a central pipe (10) extending through the piston (4) having its bottom end projecting through the disc (7) so as to produce a shock absorber in which the shock absorption can be adapted very rapidly to the frequency of movement of the unsprung wheel guide part, the damper valve being disposed at the bottom end of the central pipe (10), and a regulation device to regulate the damping exerted by the damper valve depending at least on the frequency which the working cylinder vibrates.

Dependencies are inferred from the claim text.