Adjustable shock absorber unit

Claim 1

In a shock absorber comprising an annular outer casing having a forward end and a rearward end, a pressure tube extending lengthwise within said casing and defining a chamber therebetween, a piston assembly axially movable along an axis within said pressure tube, a piston rod connected to said piston assembly and extending outwardly of said forward end of said casing for receiving impact forces, said pressure tube having at least one radial metering bore formed in the wall thereof which defines an orifice open at the outer surface of said pressure tube, and a metering sleeve surrounding said pressure tube within said casing and having a radial port adjacent said orifice for establishing the effective area thereof, said metering sleeve being axially movable relative to said pressure tube to adjust the position of said port relative to said bore to vary the effective area of said orifice to thereby regulate the flow of fluid outwardly of said pressure tube through said bore and said port to said chamber as said piston assembly moves rearwardly in said pressure tube, the improvement comprising: said outer casing having a slot therein which slot is elongated in an axial direction, pin means extending through said slot and engaging said metering sleeve, said pin means being movable in the axial direction in said slot and by said engagement with said metering sleeve imparting a corresponding movement to said sleeve, operating means externally of said casing engaging said pin means for moving said pin means axially in said slot and for locking the pin means against unintentional axial movement in said slot, and seal means for preventing fluid loss through that part of the slot not occupied by said pin, said means externally of said casing comprising an adjustment ring mounted on said casing for rotation about said axis with respect to the casing, said ring having a spiral groove on the inside thereof extending only part way through the ring in a radial direction, said pin extending into said groove; said seal means being between said ring and said casing.