Patent ID: 6736292
Filing Date: 2004-05-18
Classification: F16N,G01F

Abstract:
A pneumatic reciprocating motor comprising:a motor cylinder having a head end and a rod end; a motor piston reciprocable in the cylinder, said motor piston having a forward side and a back side, said motor piston being reciprocable through a forward stroke toward the rod end of the cylinder and a return stroke back toward the head end and being biased to return back through a return stroke; a piston rod extending forward from the motor piston through the rod end of the cylinder reciprocable by the motor piston; said cylinder having an air inlet for admission of compressed air thereto on the back side of the motor piston for driving it forward through a forward stroke against the return bias and an air outlet on the forward side of the motor piston for venting air; said motor piston having through passaging extending from its forward side to its back side; a longitudinally extending hole in the motor piston; a valve movable in the longitudinally extending hole in the motor piston between a position blocking said through passaging and a position unblocking said through passaging; seals seated in grooves in the motor piston adjacent the forward end and rearward end of the motor piston, each seal comprising a channel-section ring, an O-ring positioned in a channel of the channel-Section ring, and a ribbed formation on a periphery of the channel-section ring for slidably sealing against an interior surface of the motor cylinder; and auxiliary passaging comprising an internal recess in the motor cylinder, an annular peripheral groove in the motor piston and a passage from said annular peripheral groove to said longitudinally extending hole in the motor piston, said auxiliary passaging being adapted to deliver air under pressure from the back side of the motor piston to move the valve to its said through-passaging-unblocking position at the conclusion of a forward stroke of the motor piston.