Shock absorber with piston rod guide and seal means

Claim 1

In combination in a hydraulic shock absorber, a hollow cylinder member, a piston reciprocable within said member, a piston rod connected to said piston and extending axially outwardly from one end of said member, an annular rod guide secured within and closing one end of said cylinder member and defining an axially extending bore through which said piston rod extends, a cylindrical anti-friction bushing fabricated of low coefficient of friction polymeric material secured within said bore, first and second enlarged diameter annular chambers located one at each end of said rod guide and oriented coaxially of said bore, one of said chambers being defined by a countErbore in said rod guide and having a generally cup-shaped seal support member disposed therewithin and abuttingly engaged with one axial end of said bushing for preventing axial movement thereof toward said counterbore, a first annular elastomeric member disposed within said one chamber and having an inner peripheral portion slidably engaged with the outer periphery of said piston rod, a radial shoulder projecting interiorly of said bore at the end thereof opposite said counterbore, said shoulder being abuttingly engaged with the other axial end of said bushing, whereby said bushing is retained between said shoulder and said cup member against any axial displacement relative to said guide member, a second annular elastomeric member disposed within the other of said annular chambers and having an inner peripheral portion slidably engaged with the outer periphery of said piston rod, and a generally radially disposed retaining plate secured within said cylinder member adjacent one of said annular elastomeric members and extending radially thereover for retaining the same in said other annular compartment.