Controllable fluid damper assembly

Claim 1

In a controllable fluid damper assembly of the type having a cylinder, a piston mounted within said cylinder for reciprocatory movement along the central axis of said assembly, said piston having a peripheral side wall closely adjacent the inner surface of said cylinder and having opposite ends facing respective ones of the opposite ends of said cylinder, and a piston rod connected to one of said opposite ends of said piston and extending from an end of said cylinder, the improvement comprising: said piston having therewithin (a) at least one elongated fluid passageway having opposite sides, said passageway extending transversely of said central axis of said assembly and having terminal opposite end portions adjacent to and spaced inwardly from said peripheral side wall of said piston; (b) fluid inlet/outlet ports opening from one of said ends of said piston and extending to and communicating with respective ones of said opposite end portions of said passageway; (c) an outlet/inlet port opening from the other one of said opposite ends of said piston and communicating with said passageway at a location along the length thereof intermediate said opposite end portions of said passageway and spaced from said inlet/outlet ports; (d) a pair of valve seats located upon and recessed within opposite sides of said passageway intermediate the length thereof, said valve seats being in spaced confronting relationship to each other; valve means for controlling fluid flow through said passageway, said valve means including a valve element mounted within said passageway for movement transversely thereof between said valve seats and between an open-valve position and a closed-valve position, said valve element when in said open-valve position being received by one of said seats and spaced from the other of said seats and permitting relatively free flow of fluid through said passageway between said inlet/outlet ports and said outlet/inlet ports, and said valve element when in said closed-valve position thereof extending between and being received by both of said valve seats and obstructing flow of fluid through said passageway between said inlet/outlet ports and said outlet/inlet port; said valve element being substantially pressure-balanced in orthogonal directions, having opposite major surfaces extending transversely of said axis of said assembly and confronting respective ones of said valve seats, and having pressure-equalizing opening means extending between and opening from said surfaces for substantially equalizing fluid pressures upon said valve element surfaces; and powered actuator means for controlling said movement of said valve element.