Air motor reversing throttle

A reversing and throttling device primarily used in pneumatic hand tools is disclosed. Pressurized air enters the housing at one end. An operator depresses a lever at either end to actuate a slide valve which directs and limits the flow of air for reversing and throttling an air motor for powering various pneumatic hand tools.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to pneumatic powered hand tools. In 
particular, this invention relates to the reversing and throttling of such 
pneumatic tools. 
2. Description of the Prior Art 
Conventional pneumatic tools commonly used in assembly operations, 
dissassembly operations, and automotive repair facilities utilize a lever 
to actuate an air motor which provides the power for various pneumatic 
hand tools, i.e. drill, screw driver, ratchet, impact wrench. Reversal of 
these air tools requires the actuation of a second lever or button thus 
requiring a second hand. Throttling of these air tools is generally 
accomplished by adding a restrictor valve to control the air flow. Air 
flow control is not smoothly varied as the restrictor valve requires 
continuous adjustment. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a single lever is actuated to 
reverse and throttle various pneumatic hand tools. An operator depresses a 
lever connected to a slide valve which directs and limits the flow of 
pressurized air. By directing the flow of pressurized air with a single 
lever an air motor can be reversed quickly with one-hand operation. Such a 
device can easily reverse stuck drill bits or cross-threaded fasteners 
using one hand. Torquing such fasteners can also be more easily 
accomplished by limiting air flow with one hand. Varied speeds can be 
easily maintained with one lever. A minimul number of parts is required in 
the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, the present invention, being a reversing and 
throttling device for pneumatic powered hand tools, includes a housing 10 
having a holding means 26. The housing 10 has an inlet counterbore 15 
extending axially inward in one end. A smaller diameter inlet counterbore 
16 extends axially inward from the inlet counterbore 15. A plunger guide 
bore 36 extends axially inward from the smaller counterbore 16. An air 
passage 17 perpendicularly communicates with the smaller counterbore 16 
and terminates near one end of housing 10 circumference and its other end 
is terminated by air stoppage means 37. Air channel 18 communicates 
perpendicularly with air passage 17 near its terminated end. Air channel 
19 communicates perpendicularly with air passage 17 near its stoppage 
means end. Air channels 18 and 19 extend along the longitudinal axis of 
housing 10 and communicate perpendicularly with a valve guide bore 12. 
Valve guide bore 12 terminates near housing 10 circumference past air 
channel 18 and is exposed at housing circumference past air channel 19. An 
air channel 30 in alignment with air channel 18 intersects valve guide 
bore 12 on the opposite side of air channel 18 and is in communication 
with air chamber 33. Air channel 32 in alignment with air channel 19 
intersects valve guide bore 12 on the opposite side of air channel 19 and 
communicates with air chamber 34. Air chamber 33 extends radially downward 
along the inside circumference of housing 10 and provides communication 
between air channel 30 and an air motor 38. Air chamber 34 extends 
radially upward along inside circumference of housing 10 and provides 
communication between air channel 32 and an air motor 38. Air chambers 33 
and 34 are in non-communication. Valve guide bore 12 slidably receives a 
valve 22 which has air passage means 23 near terminated end of valve bore 
12 radially inward from air channels 18 and 30 and air passage means 29 
near valve bore 12 exposed end radially inward from air channels 19 and 
32. Aforementioned assumes invention is in neutral position wherein valve 
22 causes non-communication of all air channels. Valve 22 has a v-shaped 
notch 35 in axial alignment with plunger guide bore 36 wherein the pointed 
portion points away from plunger guide bore 36 and toward an air motor 38. 
A plunger 21 is slidably received by guide bore 36 wherein the plunger 21 
small end contacts the pointed end of the v-shaped notch 35. A sealing 
means 20 is annularly connected to the large end of plunger 21 wherein the 
sealing means 20 keeps the plunger 21 partially disposed in counterbore 15 
thus sealing counterbore 16 from pressurized air. A tension member 14 
tensions the large end of plunger 21 against counterbore 16. Opposite end 
of tension member 14 is tensioned against an inlet member 13 which is 
fastened to housing 10 at inlet of counterbore 15. Valve 22 has pivotal 
linkage means 39 linked to one end of throttle lever 31. Throttle lever 31 
is pivotally linked to holding means 26 near their centers by pivot pin 
25. Exhaust means 28 communicates air motor 38 with atmosphere. 
OPERATION OF THE PREFERRED EMBODIMENT 
Pressurized air generally between 100 and 150 pounds per square inch, is 
supplied from a suitable air source through inlet member 13 thus 
maintaining constant pressure in counterbore 15 (FIG. 1). Referring to 
FIG. 2, when throttle lever 31 is depressed at end 27, valve 22 is forced 
further into counterbore 12 causing the upper air passage 23 to come into 
alignment with air channels 18 and 30. Movement of valve 22 also causes 
plunger 21 and sealing member 20 to move toward inlet member 13 by 
actuation means 35 allowing for pressurized air within counterbore 15 to 
enter smaller counterbore 16, air passage 17, and air channels 18 and 19. 
Plunger guide bore 36 maintains axial alignment of plunger 21. Since air 
passage 23 is in alignment with air channel 18, pressurized air flows into 
air channel 30. Non-alignment of air passage 29 with air channel 19 keeps 
pressurized air from flowing to air channel 21. Pressurized air enters air 
chamber 33 enabling the operation of an air motor in counterclockwise 
direction as viewed from inlet member 13. The amount of deflection of 
throttle lever 31 determines the volume of air flow by controlling the 
degree of alignment of air passage 23 with air channels 18 and 30. 
Depression of throttle lever 31 at its opposite end 24 causes the opposite 
to occur. Pressurized air again enters smaller counterbore 16, air passage 
17, air channels 18 and 19. Amount of deflection of throttle lever 31 
causes a degreed alignment of air passage 29 with air channels 19 and 32 
allowing for controlled air flow into air chamber 34. Air passage 23 is 
now in nonalignment with air channels 18 and 30 thus halting air flow 
thereof. Air motor can now rotate in clockwise direction. Once pressurized 
air has traveled through an air motor 38 it can now be exhausted through 
exhaust chamber 28. The reversing throttle remains in neutral position 
until throttle lever 31 is depressed at either end. Air flows into air 
chamber 33 or 34 depending upon whether the throttle lever 31 is depressed 
at end 27 or end 24 respectively. Tension member 14 maintains the device 
in neutral position when throttle lever 31 is undepressed. While this 
invention has been illustrated in only one form it is obvious to one 
skilled in the art easy adaptability of the present invention to various 
air tools. A minumul number of parts is required. An operator can easily 
control reversal and speed of the present invention with one hand.