GB1358691A - Shock absorber - Google Patents

Abstract

1358691 Fluid-containing shock absorbers JONAS WOODHEAD Ltd 6 July 1971 [6 July 1970] 32580/70 Heading F2S Only the final range of travel of a piston-rod 22 or 42 into a cylinder 23 or 44 of a shock absorber, e.g. of single or double type for a vehicle suspension system, is resisted by passage of fluid through an orifice 32, Fig. 3, or orifices 45-49, Fig. 7. The cylinders 23, 44 move in dirt shields 21, 41, fixed like the pistonrods 22, 42 to a connector 24, 43 for mounting the shock absorber. When the cylinder 23 slides up the rod 22, it is slowed by compressing a polyurethane cup 30 so that liquid is forced from its interior 27 through the orifice 32 into a metal chamber 26. With subsequent expansion of the cylinder and piston, the liquid is drawn back through orifice 32 and past a valve 33 opened by pressure difference. The chamber 26 may be omitted and the orifice and a valved opening both formed in the top closure of the dirt shield. A polyurethane cup, in this case attached against the closure, contains air to be forced out through the orifice on deformation of the cup. In Fig. 7, a rigid cap 40 is fitted around the end of the cylinder 44 and, when the latter rises, the cap enters and progressively distends (see Fig. 10) a synthetic rubber cap 55 which incorporates a reinforcement 58. Oil or oil-water emulsion is thus forced from a surrounding space 64 through the graded orifices 45-49 into a surrounding polyurethane sleeve 51 which distends to create a space 66, Fig. 10. A series of lips 65, which isolate the orifices 45-49 progressively during contraction of the shock absorber, allow return flow of the oil through all the orifices, as indicated in Fig. 10, during its expansion.