Bi-directional multiple state suspension damper

Abstract

A damper provides tunable variable rates in both extension and compression operation. A piston is carried in a cylinder tube separating out extension and compression chambers. The piston carries a first valving assembly that is tuned to provide a first damping level when fluid flows through the piston from the extension chamber to the compression chamber and a second valving assembly that is tuned to provide a second damping level when fluid flows through the piston from the compression chamber to the extension chamber. A control valve assembly is mounted to move with the piston. When the control valve assembly is closed, fluid flow between the compression and extension chamber flows substantially only through the first and second valving assemblies and when the control valve is open at least some fluid flows between the compression and extension chambers through a secondary valve assembly without passing through the first and second valving assemblies. The secondary valve assembly is mounted to move with the piston and includes a third valving assembly that is tuned to provide a third damping level, and includes a fourth valving assembly that is tuned to provide a fourth damping level. When the control valve is open, fluid flow from the extension chamber to the compression chamber passes through both the first valving assembly and the third valving assembly wherein performance of the damper is determined by the first and third valving assemblies in parallel, and fluid flow from the compression chamber to the extension chamber passes through both the second valving assembly and the fourth valving assembly wherein performance of the damper is determined by the second and fourth valving assemblies in parallel.