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A pneumatic rotary tool has a housing formed primarily from plastic so that the weight and price of the tool are substantially reduced. The air motor is formed for economic assembly while permitting greater structural stability should the housing deflect under an impact. The tool includes a torque

A pneumatic rotary tool has a housing formed primarily from plastic so that the weight and price of the tool are substantially reduced. The air motor is formed for economic assembly while permitting greater structural stability should the housing deflect under an impact. The tool includes a torque selector which controls the amount of pressurized air allowed to enter the air motor, thereby controlling the torque output of the motor. The user may adjust the torque selector to a number of set positions which correspond to discrete torque values. The tool additionally incorporates early and late stage exhaust ports, so that backpressure within the air motor does not slow motor rotation or decrease tool power.

대표청구항 ▼

What is claimed is: 1. A pneumatic rotary tool comprising: a housing; an output shaft supported by the housing for rotation about its longitudinal axis and projecting from the housing for transmitting torque to an object; an air motor disposed in the housing and connected to the output shaft for dr

What is claimed is: 1. A pneumatic rotary tool comprising: a housing; an output shaft supported by the housing for rotation about its longitudinal axis and projecting from the housing for transmitting torque to an object; an air motor disposed in the housing and connected to the output shaft for driving rotation of the output shaft; and an air inlet supported by the housing and constructed for connection to a source of pressurized air for delivering pressurized air to the motor to power the motor to drive the output shaft, said air inlet further comprises an inlet cylinder, through which air passes, said housing being molded around the exterior of said inlet cylinder and holding the inlet cylinder within the housing. 2. A pneumatic rotary tool as set forth in claim 1 wherein the exterior of the inlet cylinder further comprises at least one groove for engaging a protrusion of the housing for securing the inlet cylinder within the housing. 3. A pneumatic rotary tool comprising: a plastic housing; an output shaft supported by the housing for rotation about its longitudinal axis and projecting from the housing for transmitting torque to an object; an air motor disposed in the housing and connected to the output shaft for driving rotation of the output shaft; an air inlet supported by the housing and constructed for connection to a source of pressurized air; an air passage extending from the air inlet to the motor for delivering pressurized air to the motor to power the motor to drive the output shaft; and an air exhaust supported by the housing for exhausting air from the motor to outside the tool housing; said air motor further comprising a cylindrical support sleeve having a first open end and a second open end, a rotor being rotatable within said support sleeve having a plurality of vanes which extend radially outwardly from the rotor when the rotor rotates, a first end cap attached to said first open end, and a second end cap attached to said second open end, the first and second end caps being formed separately from the support sleeve, each end cap comprising an annular projecting portion extending into a respective one of the open ends of the support sleeve and engaging the support sleeve at an internal diameter edge margin of the support sleeve to radially locate the end cap, and an annular flange engaging a respective one of the axial ends of the support sleeve to axially locate the end cap and support sleeve, the first and second end caps supporting the support sleeve in the housing against canting with respect to the housing under forces experienced by the tool in use. 4. A pneumatic rotary tool as set forth in claim 3 wherein the support sleeve and the end caps have a common central axis. 5. A pneumatic rotary tool as set forth in claim 4 wherein the housing further comprises a clutch casing encasing a clutch mechanism, the clutch casing having a back end engageable with the housing so that the output shaft extends from the outer end of the clutch casing. 6. A pneumatic rotary tool as set forth in claim 5 wherein the first end cap further comprises a front external shoulder for engaging a rear internal shoulder of the clutch casing for orienting the clutch casing and the first end cap so that the two are aligned along their cylindrical axes and inhibiting the clutch casing and the first end cap from becoming misaligned should the tool be subjected to an impact. 7. A pneumatic rotary tool as set forth in claim 6 further comprising a plurality of bolts extending through the housing and engaging with the clutch casing, the bolts cooperating to compress the internal components of the tool, securely seating the end caps to the support sleeve so that the engagement of the housing, support sleeve, end caps, clutch casing and bolts cooperate to form a tool of considerable rigidity and strength resistant to movement of the air motor with respect to the housing should the tool be subjected to an impact. 8. A pneumatic rotary tool as set forth in claim 3 further comprising a torque selector supported by the housing in a location for regulating flow of air through the air passage whereby selective adjustment of the torque selector changes the torque output of the motor. 9. A pneumatic rotary tool as set forth in claim 8 wherein the housing further comprises an end cover, said torque selector being rotatable within said end cover, said torque selector including a portion disposed in the air passage to regulate air flow in said air passage, said torque selector includes differently sized ports and is movable between a plurality of discrete positions, to place a different port in communication with the air passage for controlling the flow of air into the motor, thereby controlling the torque output of the motor. 10. A pneumatic rotary tool as set forth in claim 3 wherein the air motor has an early stage exhaust port for exhausting air from the motor into the air exhaust and a late stage exhaust port for releasing residual air from the motor to reduce back pressure within the air motor. 11. A pneumatic rotary tool as set forth in claim 3 wherein the air inlet further comprises an inlet cylinder, through which air passes, said housing being molded around the exterior of said inlet cylinder for holding the inlet cylinder within the housing. 12. A pneumatic rotary tool as set forth in claim 11 wherein the air inlet further comprises a fitting and a connector through which air passes, the fitting being removably threaded into the inlet cylinder. 13. A pneumatic rotary tool as set forth in claim 12 wherein the connector is mounted on the fitting for pivoting movement relative to the fitting. 14. A pneumatic rotary tool as set forth in claim 13 wherein the fitting includes a hex-shaped keyway sized and shaped for receiving a hex-shaped key for rotating the fitting within respect to the inlet cylinder, thereby engaging the threads and threading the fitting fully into the inlet cylinder. 15. A pneumatic rotary tool as set forth in claim 3 wherein the housing further comprises a grip extending downwardly from the housing, said grip further comprises an outer layer of soft material overmolded onto the grip and formed to cushion and ease pressure on the user's hand and increase friction between the grip and the user, allowing a user to grasp and hold the tool securely. 16. A pneumatic rotary tool comprising: a housing; an output shaft supported by the housing for rotation about its longitudinal axis and projecting from the housing for transmitting torque to an object; an air motor disposed in the housing and connected to the output shaft for driving rotation of the output shaft in the forward and reverse directions; an air inlet supported by the housing and constructed for connection to a source of pressurized air; an air passage extending from the air inlet to the motor for delivering pressurized air to the motor to power the motor and drive the output shaft; an air exhaust supported by the housing for exhausting air from the motor to outside the tool housing; and a torque selector supported by the housing in a location for regulating flow of air through the passage to the motor, said torque selector including ports of different sizes and being mounted for movement relative to the housing to bring different ones of the ports into the air passage for selectively changing the effective cross sectional area of the air passage at the location, thereby to control the flow of air and hence the torque output of the motor. 17. A pneumatic rotary tool as set forth in claim 16 wherein the ports within the torque selector are arranged in series according to size so that movement of the torque selector in one direction will increase the torque output and movement of the torque selector in the other direction will decrease torque output. 18. A pneumatic rotary tool as set forth in claim 17 wherein said ports comprise four ports of varying cross-sectional area. 19. A pneumatic rotary tool as set forth in claim 16 wherein the housing further comprises an end cover, said torque selector being rotatable within said end cover. 20. A pneumatic rotary tool as set forth in claim 19 wherein the end cover further comprises an orifice for allowing a minimum amount of pressurized air to travel through the passage irrespective of the position of the torque selector. 21. A pneumatic rotary tool as set forth in claim 20 wherein the end cover further comprises a selector passage for use in altering the effective cross-sectional area of the passage by providing another passage parallel to the orifice, thereby increasing the effective total cross-sectional area of the passage and the amount of pressurized air passing through the torque selector. 22. A pneumatic rotary tool as set forth in claim 21 wherein the torque selector is formed with ports of different size selectively positionable to permit air to enter the selector passage. 23. A pneumatic rotary tool as set forth in claim 16 wherein the air motor has an early stage exhaust port for exhausting air from the motor into the air exhaust and a late stage exhaust port for releasing residual air from the motor to reduce back pressure within the air motor. 24. A pneumatic rotary tool as set forth in claim 16 wherein said air motor further comprises a cylindrical support sleeve having a first open end and a second open end, a rotor being rotatable within said support sleeve having a plurality of vanes which extend radially outwardly from the rotor when the rotor rotates, a first end cap attached to said first open end, and a second end cap attached to said second open end, the first and second end caps being formed separately from the support sleeve, the first and second end caps engaging the support sleeve for supporting the support sleeve in the housing against canting with respect to the housing under forces experienced by the tool in use, said support sleeve and end caps being formed for radial location of the support sleeve and end caps on a common central axis. 25. A pneumatic rotary tool as set forth in claim 16 wherein the air inlet comprises an inlet cylinder, through which air passes, said housing being molded around the exterior of said inlet cylinder and holding the inlet cylinder within the housing. 26. A pneumatic rotary tool as set forth in claim 25 wherein the inlet cylinder further comprises a fitting and a connector through which air passes, the fitting being threaded into the inlet cylinder. 27. A pneumatic rotary tool as set forth in claim 26 wherein the connector is mounted on the fitting for pivoting movement relative to the fitting. 28. A pneumatic rotary tool as set forth in claim 26 wherein the fitting is capable of receiving a tool, so that the tool and fitting may rotate conjointly to thread the fitting into the inlet cylinder. 29. A pneumatic rotary tool as set forth in claim 28 wherein the fitting includes a keyway for receiving the tool. 30. A pneumatic rotary tool as set forth in claim 29 wherein the keyway is hex-shaped. 31. A pneumatic rotary tool as set forth in claim 16 wherein the housing further comprises a grip extending downwardly from the housing, said grip further comprises an outer layer of soft material overmolded onto the grip and formed to cushion and ease pressure on the user's hand and increase friction between the grip and the user, allowing a user to grasp and hold the tool securely. 32. A pneumatic rotary tool comprising: a housing; an output shaft supported by the housing for rotation about its longitudinal axis and projecting from the housing for transmitting torque to an object; an air motor disposed in the housing and connected to the output shaft for driving rotation of the output shaft in the forward and reverse directions; an air inlet supported by the housing and constructed for connection to a source of pressurized air; an air passage extending from the air inlet to the motor for delivering pressurized air to the motor to power the motor and drive the output shaft; an air exhaust supported by the housing for exhausting air from the motor to outside the tool housing; a torque selector supported by the housing in a location for regulating flow of air through the passage, said torque selector being adapted to selectively change the effective cross sectional area of the air passage at the location thereby to control the flow of air and hence the torque output of the motor; and an orifice arranged relative to the air passage and the torque selector for allowing a minimum amount of pressurized air to travel through the air passage irrespective of the torque selector. 33. A rotary vane air motor for use in a pneumatic tool comprising: a cylindrical motor housing; a rotor rotatable within the motor housing, the rotor having a plurality of vanes which extend radially outwardly from the rotor when the rotor rotates to touch the inside of the motor housing, the vane being most forward in the direction of rotation being the leading vane and the vane immediately following being the trailing vane, wherein adjacent vanes create multiple cavities within the motor for receiving a portion of compressed air as the rotor rotates and the cavities pass before an inlet port, the compressed air pushes against the a leading vane, causing the rotor to rotate, said cavities formed between each pair of adjacent vanes may be categorized according to their position within the motor housing such that when the rotor rotates each cavity moves through a power stage, an exhaust stage and a recovery stage; and an exhaust associated with the housing and arranged to permit primary and secondary exhaust to inhibit back pressure on the trailing vane in the exhaust and recovery stage. 34. A rotary vane air motor for use in a pneumatic tool as set forth in claim 33 further comprising a first exhaust port formed in the motor housing at the beginning of the exhaust stage such that as the leading vane passes the first exhaust port the compressed air is exhausted from the motor housing after the cavity completes its power stage, leaving the air within the cavity in an uncompressed state as the trailing vane passes the first exhaust port. 35. A rotary vane air motor for use in a pneumatic tool as set forth in claim 34 further comprising a second exhaust port is formed in the motor housing at the end of the exhaust stage for exhausting the remaining air from the motor housing as the cavity passes so that as the volume of the cavity decreases, back pressure does not build up against the trailing vane, thereby decreasing the torque output of the tool. 36. A rotary vane air motor as set forth in claim 35 wherein said motor housing further comprises a cylindrical support sleeve having a first open end and a second open end, said rotor being rotatable within said support sleeve, a first end cap attached to said first open end, and a second end cap attached to said second open end, the first and second end caps being formed separately from the support sleeve, the first and second end caps engaging the support sleeve for supporting the support sleeve, said end caps each comprise an annular projecting portion extending into a respective one of the open ends of the support sleeve and engaging with the support sleeve as an internal diameter edge margin of the support sleeve to radially locate the end cap, and an annular flange engaging a respective one of the axial ends of the support sleeve to axially locate the end cap and support sleeve.