Patent ID: 8627933

Claim:
A shock absorber comprising: a pressure tube forming a tube working chamber; a piston body slidably disposed within said working chamber, said piston body dividing said tube working chamber into an upper working chamber and a lower working chamber, said piston body defining a first plurality of fluid passages extending between said upper working chamber and said lower working chamber; a first valve assembly attached to said piston body, said first valve assembly comprising: a first backup washer engaging said piston body, said first backup washer having a backup washer body and a projection projecting toward said piston body from said backup washer body; a first valve disc slidably disposed on said first backup washer, said first valve disc engaging said piston body; a second valve disc engaging said first valve disc, said second valve disc closing said first plurality of fluid passages; a preload disc slidably disposed on said first backup washer, said preload disc urging said second valve disc into engagement with said first valve disc, said preload disc directly engaging said projection defined by said first backup washer; a damping chamber defined by said preload disc and said backup washer body and said projection of first backup washer; a controlled orifice extending between said damping chamber and one of said upper and lower working chamber, said controlled orifice being defined by said preload disc and said projection of said backup washer, said controlled orifice controlling damping sliding movement of said preload disc along said first backup washer by controlling fluid flow through said controlled orifice; wherein said second valve disc is movable between a first position closing said first plurality of fluid passages and a second position where said second valve disc elastically deflects to separate from said first valve disc to open said first plurality of fluid passages; and said first valve disc is movable between a first position engaging said piston body and a second position spaced from said piston body to open said first plurality of fluid passages.