Patent ID: 8727080

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 first chamber formed on one side of the piston within the housing and containing fluid and a second chamber in the housing containing fluid, the shock absorber comprising: (a) a valve in a fluid communication path between the first and second chambers, the valve having an orifice component and a moveable orifice blocker component, wherein the blocker has at least an open position in which fluid can flow through the orifice and a closed position in which the blocker substantially obstructs fluid from flowing through the orifice and wherein the orifice blocker is configured to move from the closed position to the open position solely through an inertial effect of forces that are applied to the orifice blocker and tend to cause at least a partial stroke of the shock absorber; (b) at least one biasing element disposed in the valve that exerts a first biasing force urging the blocker toward said closed position and contributes to a total biasing force that urges said blocker in the closed position to remain in said closed position; and (c) wherein every component of said total biasing force is applied to the blocker by structures contained entirely within the shock absorber and every component of said total biasing force that is controlled so as to vary said total biasing force is controlled only by at least one non-electromagnetic device selected from the group of pneumatic, hydraulic and mechanical devices; and wherein when the blocker is in the open position the first biasing force is no greater for any particular piston stroke position than said total biasing force; and wherein the first biasing force at at least one piston stroke position is insufficient by itself to return the blocker to the closed position.