Heavy duty hydraulic shock absorber

Claim 1

A shock absorber comprising: (a) an outer tube enclosed by a rear head and a front head; (b) an inner tube mounted in said outer tube and enclosed at its ends by said heads; (c) a piston assembly, including a piston rod slidably mounted in said inner tube through said front head; (d) an impact receiving button on the outer end of said piston rod for receiving loads to be decelerated; (e) a chamber formed interior of said outer tube and between said inner tube and outer tube; (f) a plurality of longitudinally spaced metering orifice means formed through said inner tube and communicating said inner tube with said chamber; (g) a metering means in said chamber for regulating flow of fluid through said orifice means when the piston assembly is moved inwardly in said inner tube by a load on said button; (h) a fluid return passage means for returning the fluid from said chamber to said inner tube when the piston assembly is moved outwardly of said inner tube after said load is decelerated; (i) each of said metering orifice means includes a set of transverse, parallel orifices disposed on a common diameter plane; (j) said metering means for regulating flow of fluid through said orifice means including a sleeve member mounted on the outer side of said inner tube over said orifices, and a slidable metering spool mounted in said sleeve member; (k) said sleeve member being provided with slot means for communicating said orifices with said chamber; (l) said metering spool being provided with a plurality of annular grooves for regulating the opening of said slot means for controlling the flow of fluid from said orifices and through said slot means and into said chamber; (m) an adjusting screw means connected to said metering spool for adjusting said metering spool in said sleeve member; (n) said slot means in said sleeve member including a plurality of first slots formed on the inner side of the sleeve member adjacent the inner tube, with each of said first slots being disposed over one of said sets of parallel orifices; (o) said slot means in said sleeve member further including a plurality of second slots, aligned with said plurality of first slots, and being formed diametrically opposite to said plurality of first slots and communicating with said chamber; and, (p) means for retaining said adjusting screw means in an adjusted position.