Shock absorbers

Claim 1

A twin tube telescopic shock absorber comprising a pair of coaxially aligned cylinders, one cylinder being located within the other, a foot valve assembly being located at one end region of the inner cylinder to control fluid flow between the inner cylinder and the annular cavity between the cylinders, and a piston being axially slidably arranged within the inner cylinder, an electromagnetically controlled valve being arranged to provide a fluid flow path bypassing the piston, the electromagnetically controlled valve being electrically connected to the outside of the shock absorber via an electrical connection which extends through a piston rod connected to the piston, and being closed when de-energised, the electromagnetically controlled valve comprising at least one bore extending axially through the piston, a flexible closure member of planar configuration, engaging against the rear face of the piston and having a restrictor aperture which is aligned with the bore, the flexible closure member being secured to said piston rear face at a point remote from said bore, a closure plate engaging over and being spring biased against said closure member to thus close the aperture and aligned bore, an electromagnet mounted on a piston rod connected to the rear face of the piston being capable, when energised, of lifting the closure plate off the closure member, to uncover the restrictor aperture in the closure member, allowing fluid to flow through the bore as the piston is moved axially within the cylinder.