Abstract: An apparatus for damping the movement of the body of an automobile. The apparatus includes a shock absorber having a pressure cylinder which forms a working chamber and a first and second portion. A first sensor is used to generate an electrical signal in response to whether the shock absorber is in compression or rebound. A second sensor is used for determining the movement of the body on the automobile. An electronic control module is used for generating an electrical control signal in response to the outputs of the first and second sensors. A solenoid is used for regulating the flow of damping fluid between the first and second portions of the working chamber. A piston assembly disposed within the pressure cylinder defines the first and second portions of the working chamber. The piston assembly includes a valve body and first and second unloaders adapted to control the flow of fluid between the first and second portions of the working chamber.

Abstract: A shock absorber for damping the relative movement of the sprung portion of the automobile with respect to the unsprung portion of the automobile. The shock absorber includes a pressure cylinder and a piston disposed within the pressure cylinder. The piston is able to control the flow of damping fluid between the first and second portions of the working chamber so as to generate firm and soft damping characteristics. The shock absorber also includes a reserve cylinder disposed exterior of the pressure cylinder, and a base valve disposed at one end of the pressure cylinder. The base valve is operable to control the flow of damping fluid between the second portion of the working chamber and the reserve chamber in response to the flow of damping fluid between the first and second portions of the working chamber.