An air motor

Abstract

An air motor ( 10 ) that has opposing chambers ( 16, 17 ) to which compressed air is alternatively delivered to drive the motor ( 10 ). The motor ( 10 ) has a primary valve ( 52 ) that governs deli very of the compressed air to the chambers ( 16, 17 ) so at least part of the compressed air is transferred to the other chamber to aid in driving the pistons ( 18 ).

What is claimed is: 
     
         1 .- 10 . (canceled) 
     
     
         11 . A motor that is driven by a compressed fluid, the motor including:
 a first working chamber;   a first piston at least aiding in enclosing the first chamber;   a second working chamber;   a second piston at least aiding in enclosing the second chamber;   a compressed fluid inlet;   an exhaust fluid outlet;   ducting and a valve assembly connecting the chambers, inlet and outlet so that the fluid is allowed to enter and leave the chambers to move the pistons; and wherein   the valve assembly enables passage of the fluid between the two chambers.   
     
     
         12 . The motor of claim  1 , wherein the valve assemblies is configured to sequentially connect each the chambers to the air inlet and air outlet, with the chambers being connected to enable the fluid to be transferred therebetween before one of the chambers is connected to the inlet. 
     
     
         13 . The motor of claim  1 , wherein the motor further includes a controller to control operation of the valve assembly. 
     
     
         14 . The motor of claim  1 , wherein the valve assembly is a primary valve assembly, and the controller is a pilot valve assembly. 
     
     
         15 . The motor of claim  4 , wherein the primary valve assembly includes a movable valve member having a plurality of passages, and a plurality of ports surrounding the valve member, with the passages in the movable valve member connecting the ports to provide for the flow of the fluid through the valve assembly. 
     
     
         16 . The motor of claim  5 , wherein the ports include a plurality of ports connected to the inlet, a plurality of ports connected to the outlet, and a plurality of ports connecting the chambers, with the valve member being moved to sequentially connect the chambers to the inlet and outlet, and to connect the chambers. 
     
     
         17 . The motor of claim  5 , further including:
 a base;   a piston rod mounted in the base and coupling the piston so that the pistons move in unison; and   a valve cavity within which the movable valve member is located.   
     
     
         18 . The motor of claim  5 , wherein the movable valve member has a longitudinal axis, with passages being located at longitudinally spaced locations along the movable valve member. 
     
     
         19 . The motor of claim  8 , wherein the ports are located, relative to said longitudinal axis, at longitudinally spaced positions. 
     
     
         20 . The motor of claim  1 , wherein the motor is configured to receive compressed air as the driving fluid.