Abstract The air motor has substantially the size of a standard fountain pen and includes an extruded cylindrical casing formed with a circular cross-section eccentric inner surface which has annular grooves in its forward part and a smooth surface, substantially coincident with the bases of the grooves, in its rear part. The grooves constitute air supply and exhaust passages, a retainer groove and a pin groove. A front retainer closes the forward end of the casing and has a tongue projecting into the retainer groove to maintain a predetermined angular orientation in the casing, and a rear retainer is seated against the ribs defining the grooves in the forward portion of the casing and has a tongue projecting into the retainer groove to maintain a relative angular orientation with respect to the front retainer. A motor cylinder is mounted in the casing between the two retainers and has air supply and exhaust ports communicating with the air supply and exhaust passages, respectively. A vane type rotor is rotatably supported in the two retainers, through bearings, and is eccentric to the motor cylinder. The forward end of the rotor is formed with a shaft by means of which a grinder or another tool can be secured to the rotor. The portion of the casing rearwardly of the rear retainer constitutes an air supply and control chamber in which there is an air filter means, and the air passing through the filter means flows through supply passages in the rear retainer into the air supply passage. A connection is provided at the rear of the casing for connecting the air motor to a source of air under pressure, and a manually operable grip threaded on this connection controls the supply of air under pressure to the supply and control chamber. In a modification of the air motor, the exhaust air flows rearwardly along the exterior surface of the motor cylinder and through sound absorbing means to exhaust ports leading to the atmosphere or to an exhaust line.
A grinder driven by an air motor comprising, in combination, a tubular extrusion defining a relatively elongated tubular casing having a circular cross-section inner surface which is eccentric to the axis of said casing and which is formed with angularly spaced longitudinal grooves extending through at least a portion of the length of said casing and defining air supply and exhaust passage means; means dividing the interior of said casing into a front motor chamber having said grooves therein and a rear air supply and control chamber, a tubular motor cylinder in said motor chamber having a smooth cylindrical outer surface engaging the circular cross-section inner surface of said casing and having radial ports communicating with said air supply and exhaust passage means; an air pressure rotated cylindrical rotor rotatably mounted in said motor cylinder; a shaft projecting from the front end of said rotor for connection to a tool to be driven by said motor; said dividing means having ports connecting said supply and control chamber to said air supply passage means; exhaust port means connecting said exhaust passage means to atmosphere; a connection at the rear of said casing for connecting said air motor to a source of air under pressure, a manually operable control valve controlling communication between said connection and said supply and control chamber; the front end of said casing being externally threaded; a grinder housing threaded onto the front end of said casing; a first bevel gear secured to said shaft and disposed in said grinder housing; a second bevel gear meshing with said first bevel gear; antifriction means rotatably mounting said second bevel gear in said grinder housing for rotation about an axis perpendicular to the axis of said first-mentioned shaft; and means securing a grinder to said second bevel gear.
Claim 2
Dependent Claim
298 words
A grinder driven by an air motor comprising, in combination, a tubular extrusion defining a relatively elongated tubular casing having a circular cross-section inner surface which is eccentric to the axis of said casing and which is formed with angularly spaced longitudinal grooves extending through at least a portion of the length of said casing and defining air supply and exhaust passage means; means dividing the interior of said casing into a front motor chamber having said grooves therein and a rear air supply and control chamber, a tubular motor cylinder in said motor chamber having a smooth cylindrical outer surface engaging the circular cross-section inner surface of said casing and having radial ports communicating with said air supply and exhaust passage means; an air pressure rotated cylindrical rotor rotatably mounted in said motor cylinder; a shaft projecting from the front end of said rotor for connection to a tool to be driven by said motor; said dividing means having ports connecting said supply and control chamber to said air supply passage means; exhaust port means connecting said exhaust passage means to atmosphere; a connection at the rear of said casing for connecting said air motor to a source of air under pressure, a manually operable control valve controlling communication between said connection and said supply and control chamber; the front end of said casing being externally threaded; a grinder housing threaded onto the front end of said casing; a first bevel gear secured to said shaft and disposed in said grinder housing; a second bevel gear meshing with said first bevel gear; antifriction means rotatably mounting said second bevel gear in said grinder housing for rotation about an axis perpendicular to the axis of said first-mentioned shaft; and means securing a grinder to said second bevel gear.
Claim 3
Dependent Claim
84 words
A grinder driven by an air motor, as claimed in claim 1, in which said second bevel gear has a relatively elongated hub threaded at its outer end; a retainer threaded on the hub of said second bevel gear; said means securing said grinder to said second bevel gear comprising a bolt engaged with said grinder and extending through a central opening in said retainer and having a threaded end engaged in a threaded axial bore in the hub of said second bevel gear.