Abstract: A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. The piston assembly includes a frequency dependent valve assembly attached to the piston rod which defines a housing attached to the piston rod and a spool valve assembly. The spool valve assembly includes a spool valve and first and second bypass valve assemblies that control fluid flow through bypass passage that bypasses the piston assembly.

Abstract: A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. The piston assembly includes a frequency dependent valve assembly attached to the piston rod which defines a housing attached to the piston rod and a spool valve assembly. The spool valve assembly includes a spool valve and a bypass valve assembly that controls fluid flow through bypass passage that bypasses the piston assembly.

Abstract: A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. The piston assembly includes a frequency dependent valve assembly attached to the piston rod which defines a housing attached to the piston rod and a spool valve assembly. The spool valve assembly includes a spool valve and first and second bypass valve assemblies that control fluid flow through bypass passage that bypasses the piston assembly.

Abstract: A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. The piston assembly includes a frequency dependent valve assembly attached to the piston rod which defines a housing attached to the piston rod and a piston disposed within the housing. The piston moves within the housing to control the fluid flow through a bypass fluid passage that bypasses the piston assembly.

Abstract: A shock absorber includes a piston assembly which includes separate flow paths. Each flow path is controlled by a valve assembly and each flow path is in parallel with the other two flow paths. One flow path will generate firm damping characteristics. A second flow path opens depending on either the frequency of the shock absorber movement or the amount of movement or stroke of the shock absorber. The third flow path includes an on/off control valve and generates a soft damping characteristic when the control valve is activated. The soft damping characteristic can be generated by a tunable bleed restriction or by a passive valve assembly.

Abstract: A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. The piston assembly includes a frequency dependent valve assembly attached to the piston rod which defines a housing attached to the piston rod and a spool valve assembly. The spool valve assembly includes a spool valve and a bypass valve assembly that controls fluid flow through bypass passage that bypasses the piston assembly.

Abstract: A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. The piston assembly includes a frequency dependent valve assembly attached to the piston rod which defines a housing attached to the piston rod and a piston disposed within the housing. The piston moves within the housing to control the fluid flow through a bypass fluid passage that bypasses the piston assembly.

Abstract: A shock absorber includes a piston assembly which includes separate flow paths. Each flow path is controlled by a valve assembly and each flow path is in parallel with the other two flow paths. One flow path will generate firm damping characteristics. A second flow path opens depending on either the frequency of the shock absorber movement or the amount of movement or stroke of the shock absorber. The third flow path includes an on/off control valve and generates a soft damping characteristic when the control valve is activated. The soft damping characteristic can be generated by a tunable bleed restriction or by a passive valve assembly.