Twin piston shock absorber
AssigneeTenneco Automotive Operating Company Inc.
InventorSjaak Schel
Life of this patent
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Abstract
A two-stage piston has a twin piston design where one piston produces a high damping force and the second piston produces a low damping force. At specified positions along the pressure tube, by-pass passages are formed to allow fluid flow around the high damping force piston to provide a low damping force or a soft ride. In the areas of the pressure tube where there are no by-pass passages, the high damping force piston provides a high damping force or a firm ride. In the area of the pressure tube where there are no by-pass passages, the high damping force piston and the low damping force piston both contribute to the high damping force.
Claims16
A two-stage shock absorber comprising:
- a pressure tube defining a chamber, said pressure tube having a wall defining a by-pass passage open to said chamber, said by-pass passage extending over a first length in an axial direction of said tube;
- a first piston slidably disposed within said chamber;
- a first seal disposed between said first piston and said wall of said pressure tube, said first seal extending over a second length in said axial direction of said tube, said second length being greater than said first length;
- a second piston slidably disposed within said chamber;
- a second seal disposed between said second piston and said wall of said pressure tube, said second seal extending over a third length in said axial direction of said tube, said third length being less than said first length;
- and
- a piston rod attached to said first and second pistons.
Dependencies are inferred from the claim text.