Patent ID: 9605689
Date: 2017-03-28
CPC Classifications: F04B,F15B

Claim:
1. An air motor, comprising: a source of pressurized air; two air chambers; a directional control valve including two air distribution passages in communication with the two air chambers, respectively, a reciprocating valve spool having a land in continuous communication with the source of pressurized air, a first piston surface in continuous communication with the source of pressurized air, a second piston surface larger than the first piston surface in alternating communication with the source of pressurized air and with atmosphere and a third piston surface in continuous communication with atmosphere, the land being pneumatically between the two air distribution passages and controlling communication between the source of pressurized air and the two air distribution passages, and a restricted port in continuous communication with the source of pressurized air, the restricted port being flow restricted to provide partial pressure above atmosphere on the third piston surface and being in alternating communication with the second piston surface and the third piston surface, the first and third piston surfaces being opposed to the second piston surface.