Patent ID: 6918473
Filing Date: 2005-07-19
Classification: F16F

Abstract:
1. A two-stage shock absorber comprising: a pressure tube defining a chamber; a piston member slidably disposed within said pressure tube, said piston member dividing said chamber into an upper working chamber and a lower working chamber; a piston rod extending through said upper working chamber and projecting out of said pressure tube, said piston rod being attached to said piston member; a first valve assembly attached to said piston member, said first valve assembly permitting fluid flow from said upper working chamber to said lower working chamber through a first passage defined by said piston member, said first valve assembly restricting fluid flow from said lower working chamber to upper said working chamber; a second valve assembly attached to said piston member, said second valve assembly permitting fluid flow from said lower working chamber to said upper working chamber through a second passage defined by said piston member, said second valve assembly restricting fluid flow from said upper working chamber to said lower working chamber; a housing attached to said piston rod, said housing defining a pressure chamber; a piston slidably disposed within said pressure chamber, said piston dividing said pressure chamber into a lower fluid chamber and an upper fluid chamber within said housing; a first bleed valve assembly disposed between said upper fluid chamber and said upper fluid chamber, said first bleed valve assembly controlling fluid flow between said pressure chamber and said upper fluid chamber, said first bleed valve assembly including a first needle extending through a first restriction; and a third passage defined through said piston rod, said third passage extending between said upper working chamber and said upper fluid chamber.