Pneumatic motor with muffled exhaust

Claim 1

In a pneumatic motor that includes a vaned rotor, a rotor chamber having a gas inlet and gas outlet means, a housing and an axially extending rotor shaft to rotate in said chamber, structure to control and muffle the escape of exhaust gas comprising a. a first exhaust chamber extending about the rotor chamber and into which pressurized exhaust gas escapes from the rotor chamber, b. a second exhaust chamber spaced axially from the first exhaust chamber and extending about the shaft, and primary porting communicating between the first and second exhaust chambers, said primary porting including multiple flow restricting ports circularly spaced about said shaft and spaced radially outwardly therefrom, c. a third exhaust chamber extending about the shaft and located radially inwardly of the second exxhaust chamber, there being radially inwardly extending porting spaced about the shaft and communicating between the second and third exhaust chambers to direct escaping exhaust directionally inwardly and in conflicting turbulent streams to dissipate energy contained in said streams, d. there being additional exhaust gas escape porting extending generally axially from said third chamber and communicating with the exterior via radially directed outlets, e. and a sleeve supported on the housing for rotation and progressive axial displacement in progressively closing relation with said outlets to selectively and variably control the escape of exhaust gas therefrom, said sleeve having threading connected with threading on the housing to provide said progressive axial displacement in response to said rotation of the sleeve relative to the housing.