Patent ID: 8104591

Claim:
A shock absorber having a housing with a cylindrical sidewall, a piston slidably mounted for reciprocating through a piston stroke in, and sealingly engaging, the sidewall, a compression chamber formed on one side of the piston within the housing and containing fluid, a rebound chamber in the housing containing fluid, a reservoir chamber accommodating a variable volume of fluid, said reservoir chamber in fluid communication with the compression chamber, the shock absorber comprising: (a) a valve in a fluid communication path between the compression chamber and one of the chambers selected from the group consisting of the rebound chamber and the reservoir chamber, the valve having an orifice portion and an orifice blocker portion, wherein at least one of said valve portions is moveable relative to the other of said valve portions between at least (i) an open valve position in which fluid can flow through the orifice and (ii) a closed valve position in which the blocker substantially obstructs fluid from flowing through the orifice; (b) at least one non-electromagnetic biasing element disposed in the valve that exerts a biasing force urging said at least one moveable valve portion toward said closed valve position and contributes to a total biasing force that urges said at least one moveable valve portion already in the closed valve position to remain in said closed valve position; and (c) wherein every component of said total biasing force is applied by non-electromagnetic structures and every component of said total biasing force that is controlled is controlled only by at least one device selected from the group consisting of non-electrical pneumatic, non-electrical hydraulic and non-electrical mechanical devices; and wherein when the valve is in the open valve position the biasing force urging said at least one moveable valve portion back to the closed valve position is no greater for any particular piston stroke position than said corresponding total biasing force at said particular piston stroke position.