US Patent 9695899 Multi-stage shock absorber

A jounce control damping system with an elongated housing containing a damping medium, a primary piston assembly, a moveable outer piston assembly, and a movable inner piston assembly disposed at least partially within the outer piston assembly. The primary piston assembly provides a first compression damping force. The inner piston engages the primary piston assembly and provides a second compression damping force when moved in a compression direction. After the inner piston assembly moves a given distance, the outer piston assembly is moved in the compressive direction and provides a third compression damping force.