Patent ID: 6173965
Filing Date: 2001-01-16
Classification: F15B,F16J

Abstract:
An assembly, comprising:a pneumatic actuator piston that is reciprocal within an actuator cylinder, said actuator cylinder having a cylinder surface, said pneumatic actuator piston defining therein a piston groove that encircles said pneumatic actuator piston, said piston groove having a piston groove width measured parallel to an axis of said pneumatic actuator piston, and a bottom groove surface such that said bottom groove surface is a side of said groove closest to said axis of said pneumatic actuator piston;rack teeth mounted on said pneumatic actuator piston;a rotary member with mating teeth thereon for engaging said rack teeth;a compressible seal ring for encircling said pneumatic actuator piston and being mountable within said piston groove, said compressible seal ring being sealingly engagable between said bottom groove surface and said cylinder surface; anda non-metallic substantially non-compressible bearing ring for encircling said pneumatic actuator piston, said bearing ring being sufficiently non-compressible to prevent contact between said cylinder surface and said pneumatic actuator piston as said rack teeth engage said mating teeth of said rotary member and thereby produce a force component on said pneumatic actuator piston transverse to said axis of said pneumatic actuator piston, said bearing ring being mountable within said piston groove adjacent said compressible seal ring, said bearing ring being sized to engage said bottom groove surface and said cylinder surface such that said bearing ring extends radially outwardly from said pneumatic actuator piston to thereby engage said cylinder surface and substantially center said pneumatic actuator piston within said actuator cylinder to prevent metal-to-metal contact between said pneumatic actuator piston and said cylinder surface, said bearing ring having a lateral support side engageable with said compressible seal ring, said lateral support side defining therein a bearing ring concave groove, said bearing ring and said compressible seal ring being separable with respect to each other so as to be separably mountable within said piston groove.