US3834467A - Power tool with torque control - Google Patents

Abstract

The drawings illustrate a power tool whose torque output may be continuously measured and controlled by the torque reaction on a rotatably mounted planetary ring gear, with transducer means associated therewith for converting the torque reaction to a fluid pressure signal to cut off the fluid flow to the motor rotor at a predetermined torque.

Description

United States Patent 1191 Fuchs 1 Sept. 10, 1974 POWER TOOL WITH TORQUE CONTROL 3,279,244 10/1966 Emmerling 73/136 R 3,613,853 10/l97l Linthicum..... 173/12 X [75] Invent Fuchs Leawmd Kans- 3,664,474 5/1972 Blake et al 73/136 D [73] Assignee: General Motors Corporation, 1

Detroit, Mich. Primary ExaminerErnest R. Purser o Attorney, Agent, or Firm.l0hn P. Moran [21] Appl. No.: 304,149

[57]ABSTRACT 52 US. Cl 173/12, 73/136 D, 192/150 The drawings illustrate a POWer WhOSe "W 51 Int. Cl B25b 23/14 P may be measured and mmmlled by [58] Field M Search 173/12. 192/150. 73/136 R the torque reaction on a rotatably mounted planetary 73/136 'ring gear, with transducer means associated therewith for converting the torque reaction to a fluid pressure [56] References Cited signal to cut off the fluid flow to the motor rotor at a UNITED STATES PATENTS predetemmed mrque' 2,724,266 11/1955 Baker et al 73/136 R 11 Claims, 13 Drawing Figures PAlameoswmw m 4 3.834.4 7

MAXIMUM MAYIMUM PRESSURE PRESSURE POWER TOOL WITH TORQUE CONTROL This invention relates generally to power tools and, more particularly, to torque-controlled tools.

At the present time torque-controlled power tools are known to include valving actuated in response to torque output which serves to block the exhaust and stall the motor. Other arrangements include back pressure-sensing devices which upset a delicately balanced poppet, in response to torque output, to cut off incoming air. Still other present day arrangements include mechanical linkage for controlling an incoming airpoppet valve in response to torque output. Additional designs include spring-loaded clutches which become disengaged at a predetermined spring tension in response to output torque.

It should also be noted that the prior art torquecontrolled tools which include planetary gearing for reducing a fast motor speed to a practical output speed for most applications, generally include a planetary ring gear which is secured to the outer shell of the tool.

An object of the invention is to provide an improved rotary power tool whose output torque may be continuously controlled and/or measured by resistance to the reactive torque of a ring gear of a planetary drive unit thereof which ring gear is arranged to rotate through a predetermined arc in response to output torque.

Another object of the invention is to provide an improved torque-controlled power tool, wherein the ring gear of one of the planetary drive units thereof is rotat ably mounted, with transducer means associated therewith for responding to the rotary reaction of the planetary ring gear to output torque to provide a fluid pressure signal, upon attainment of a predetermined torque, to cut off the air supply to the motor.

A further object of the invention is to provide a torque-controlled power tool including a rotatably mounted planetary ring responsive to output torque, and transducer means responsive to such rotary movement of the ring gear to cut off the air supply to the motor section rotor, with the transducer being encased within the power tool housing.

Still another object of the invention is to provide a torque-controlled power tool including a rotatably mounted planetary ring gear responsive to output torque and which is formed integrally on a cam follower member having rollers associated therewith and riding on camming ramps formed on a cam spline member which is moved axially when the rollers move along the ramps, with the axial movement thereof compressing a plurality of adjacent bellows, for providing a fluid pressure signal indicative of output torque to cut off the air supply to the motor section of the power tool upon the attainment of a predetermined output torque.

A still further object of the invention is to provide a torque-controlled power tool including a rotatably mounted planetary ring gear responsive to output torque and having a shoe and linkage member rotatable with the ring gear to tangentially compresa a bellows or a pressure-sensing load cell, for example, providing a fluid pressure signal to cut off the air supply to the motor upon the attainment of a predetermined output torque.

These and other objects and advantages of the invention will be apparent when reference is made to the following description and accompanying drawings, wherein:

FIG. 1 is a perspective view of a rotary power tool embodying the invention;

FIGS. 2a and 2b are cross-sectional views of the FIG. 1 structure;

FIG. 2c is a schematic view of a fluidal circuit which may be used with the FIGS. 2a and 2b structures;

FIG. 3 is a fragmentary cross-sectional view of a portion of the FIG. 2a structure illustrating an operational position thereof;

FIG. 4 is a schematic view of selected operational conditions;

FIG. 5 is a fragmentary perspective view of an alternate embodiment of the FIG. 1 structure;

FIG. 6 is a fragmentary cross-sectional view of a portion of the FIG. 5 structure;

FIG. 7 is a cross-sectional view taken along the plane of line 7-7 of FIG. 5, and looking in the direction of the arrows;

FIG. 8 is an end view taken along the plane of line 8-8 of FIG. 7, and looking in the direction of the arrows;

FIG. 9 is a cross-sectional view. similar to FIG. 7, illustrating an operational position thereof;

FIG. 10 is a fragmentary cross-sectional view illustrating an alternate embodiment of the FIG. 7 arrangement; and

FIG. 11 is a fragmentary cross-sectional view illustrating an alternate embodiment of a portion of the FIG. 2b structure.

FIGURES 1-4 EMBODIMENT Referring now to the drawings in greater detail, FIG. 1 illustrates apower tool assembly 10, including generally ahandle section 12, amotor section 14, atransducer section 16, aplanetary section 18, and ahead section 20.

More specifically, as may be noted in FIG. 2b, thehandle section 12 includes a valve assembly 21 mounted in a transverse opening 22 formed through awall portion 24 in thehandle section 12 adjacent anair inlet chamber 26 to which air is communicated via an air inlet fitting 28 (FIG. I) mounted in the end of thehandle section 12. The valve assembly 21 includes asleeve member 30 secured in the opening 22 and having a central chamber 31. Aspring 32 is mounted between theouter end face 34 of thesleeve member 30 and amanual button 36. Thebutton 36 is secured to avalve stem 38 having an O-ring seal 40 mounted therearound and slidably mounted within thesleeve member 30. A frusto-conical valve 42 is formed on the inner end of thevalve stem 38 for cooperation with a valve seat member 44 formed on the inner end 46 of thesleeve member 30. An extension shaft 48 formed on the valve 42 extends across a passage 50 adjacent thechamber 26 and is slidably mounted in anopening 52 which may be formed in aplug member 54 threadedly mounted in a threadedopening 56 formed in the handle section axially aligned with the opening 22. An 0-ring seal 57 is mounted around the extension shaft 48 in the opening 52.

A plurality of ports 58 are formed in the fixedsleeve member 30 for communication with apassage 60 which, in turn, communicates with a chamber 61 which is divided into twovariable chambers 62 and 63 by apoppet valve 64 slidably mounted therein. Apassage 66 communicates between thechambers 62 and 63 radially outwardly of thepoppet valve 64. A stem 67 is formed on thepoppet valve 64, extending away from thesleeve member 30. Anaxial passage 68 is formed part-way through the stem 67, including ableed plug 70 secured in the right end (FIG. 2b) of theaxial passage 68. Radial ports 72 and 74 are formed in the stem 67 a predetermined distance apart, the ports 72 communicating between theaxial passage 68 and the chamber 62 to the left of thepoppet valve 64. An opening 75 communicates between the left chamber 62 and achamber 76 and, thence, with asupply passage 77.

The stem 67 is slidably mounted in and extends through an axial opening 78 formed in apiston housing 7 80 secured in a central opening or chamber 82 formed in thehandle section 12. A piston 84 is secured to the end of the stem 67 opposite thepoppet valve 64 and is slidably mounted in achamber 86 of thepiston housing 80, dividing thechamber 86 into twovariable chambers 87 and 88. A suitable seal 89 is mounted around the outer periphery of the piston 84 within thechamber 86. A spring 90 is mounted between the piston 84 and an end wall 92 of thechamber 86. Asignal inlet port 94 is formed in thehandle section 12 communicating with thechamber 86 to the right (FIG. 2b) of the piston 84, while ableed port 96 formed in thehandle section 12 communicates thechamber 86 to the left (FIG. 2b) of the piston 84 to the atmosphere.

Themotor section 14 includes amotor rotor 98 mounted within asleeve member 100 secured by pins 102 to thehandle section 12. Anouter vane portion 103 of themotor rotor 98 receives air under pressure in a conventional manner from thesupply passage 77 via suitable conduitry (not shown). Amotor shaft 104 is formed on themotor rotor 98 and rotatably mounted in bearings 106 (FIG. 2b), 108 (FIG. 2a), and 110 mounted in thehandle section 12, themotor section 14 and theplanetary section 18, respectively. Anannular chamber 112 is formed around thesleeve member 100, withexhaust ports 114 communicating with the atmosphere.Suitable seals 116 and 118 are mounted adjacent the respective ends of theannular chamber 112.

Anoutlet port 120 is formed in thetransducer section 16, communicating internally with an annular passage 1l2 which, in turn, communicates with a pair ofports 124 formed in a fixedwall 125 of themotor section 14, and leading, respectively, to a pair ofbellows 126 located radially outwardly of an intermediate portiori of themotor shaft 104. Thebellows 126 are mounted between thefixed wall 125 and anend face 128 of acam spline member 130, the latter being slidably mounted onsplines 132 formed in achamber 134 within thetransducer section 16, and the open end of thebellows 126 being sealed by an O-ring seal 133 mounted in agroove 135 formed in thewall 125. Aspring 136 is mounted around themotor shaft 104 between theend face 128 and an annular groove 137 formed in thewall 125. Aline 138 communicates between the outlet port 120 (FIG. 2a) and a suitable adjustable valve means, represented by 139. A line 141 communicates a fluid pressure signal from the valve means 139 to thesignal inlet port 94 and, thence, to thechamber 87 once the pressure within thebellows 126 reaches a predetermined level. As illustrated in FIG. 2c. air is supplied from any suitable high pressure source, represented at 143, through aline 145 including a pressure regulator 147 and a check valve 149, the latter providing a predetermined amount of preloading of thebellows 126. Pressure within theline 138 may be around an internallytoothed ring gear 152 of a firstplanetary unit 154, thering gear 152 being integrally formed on theroller carrier 148 for rotation therewith. Thebearing 150 is mounted within a steppedsleeve member 156 mounted within theplanetary section 18 and restrained from movement therein by a fixedradial pin 158.

A plurality of pinion gears 160 are rotatably mounted on a shaft or pin 162 by needle bearings 164. The shaft 164 is secured to apinion gear carrier 166 mounted at one end thereof within thecam follower 148 onbearings 168. The pinion gears 160 mesh with thering gear 152 and with a sun gear 170 mounted on theend portion 172 of themotor shaft 104 by splines 174. A cylindrical spacer 176 is mounted around themotor shaft 104 between oppositely disposed end faces of the sun gear 170 and the bearing 110, with the sun gear 170 being retained against the spacer 176 by a retainer ring 178 secured to theshaft end portion 172.

A secondplanetary unit 180 includes an internallytoothed ring gear 182 formed integrally on the forward end portion of the steppedsleeve member 156, a plurality of pinion gears 184 rotatably mounted on shafts orpins 186 by needle bearings 187 and by acarrier 188 having a reducedforward end portion 189 rotatably mounted onbearings 190 retained axially by aretainer ring 191 within theouter shell 193 of thehead section 20. The pinion gears 184 mesh with thering gear 182 and with a splined sun gear 192 formed on anend 194 of thecarrier 166 of the firstplanetary unit 154.

A plurality ofsplines 196 are formed on the inner surface of thecarrier 188, radially inwardly of thebearings 190. Thesplines 196 mesh withsplines 198 formed on anend 200 of ashaft 202 extending into thehead section 20, being rotatably supported therein on a plurality ofneedle bearings 204.

Afirst bevel gear 206 is formed on the forward end of theshaft 202 for meshing with asecond bevel gear 208 formed on atransverse shaft 210 rotatably mounted onbearings 212 and 214 in thehead section 20. A squaredrive tool connector 216 is formed on theshaft 202, extending through anopening 218 formed in thehead section 20, at right angles to the axis of the aligned planetary, transducer, motor, and handlesec tions 18, 16, 14, and 12, respectively. Any suitable tool fastener device (not shown) may be connected to the squaredrive tool connector 216.

OPERATION High pressure air enters theair inlet chamber 26 and the adjacent passage 50 via the fitting 28 from any suitable source (not shown). Once thevalve button 36 is manually depressed, the high pressure air is communicated from the passage 50 past the valve seat member 44 into the chamber 31, through the ports 58 into thepassage 60 and the chamber 62, and, thence, through thepassage 66, thechamber 63, the opening 75, and thechamber 76, to theadjacent supply passage 77 which communicates with theouter vane portion 103 of themotor rotor 98 to rotate themotor rotor 98 and itsshaft 104. The air is exhausted to the atmosphere via theannular chamber 112 and theexhaust ports 114.

Rotation of themotorshaft 104 rotates the sun gear 170 of the firstplanetary unit 154 therewith, for example, in a clockwise direction as viewed from the right in FIG. 2a. Such rotation of the sun gear 170 causes the pinion gears 160 to each rotate in a counterclockwise direction about itsrespective shaft 162, while meshing with thering gear 152, with thecarrier 166 being caused to rotate in a counterclockwise direction about the axis of themotor shaft 104. Thering gear 152 is initially restrained from rotating by virtue of therollers 144 on thecam follower 148 being positioned at the low point or start position (FIG. 4) of the fixedramps 140.

Rotation of thecarrier 166 at itsend portion 194 causes the sun gear 192 of the secondplanetary unit 180 to also rotate in the counterclockwise direction, thereby rotating the pinion gears 184, which are meshing with the fixedring gear 182, in a clockwise direction about theirrespective shafts 186, and thecarrier 188 in a clockwise direction about the axis of thecarrier end portion 194. Such clockwise rotation of thecarrier 188 directly rotates theshaft 202 via thesplines 196 and 198, thereby rotating thebevel gears 206 and 208 and thetool drive connector 216.

As indicated above, thering gear 152 of the firstplanetary unit 154 is initially restrained by virtue of being formed on thecam follower 148 whoserollers 144 are initially seated against the low portions of therespective ramps 140 of the fixedcam spline member 132, the latter being urged leftwardly in FIGS. 2a and 3 by thespring 136. However, as torque at the output end of thetool drive connector 216 increases under load conditions, the reaction sensed by thering gear 152 overcomes the force of thespring 136, causing thering gear 152 to move in the clockwise direction, as urged by the pinion gears 160, thus rotating thecam follower 148 and therollers 144. Such rotation of therollers 144 moves the latter along theramps 104 toward the maximum pressure position (FIG. 4), forcing thecam spline member 130 to slide axially along thesplines 132, compressing the pair ofbellows 126 to build up the pressure therein to a predetermined point.

As illustrated in FIG. 4, the maximum pressure or stop position of eachroller 144 is at some predetermined point adjacent the elevated end of therespective ramps 140, say, for example, 135 degrees away from the low end or start position. Any point between the start position and the maximum pressure position may be selected as the release point for the transmission of the fluid pressure signal and is determined by the adjustment of the valve means 139. At this point, the pressure within thebellows 126, transmitted via theline 138 to the valve means 139, will be relayed as a fluid pressure signal through the line 141 to thesignal inlet port 94. This fluid pressure signal is communicated from theinlet port 94 to thechamber 87, moving the piston 84 to the left in FIG. 2b, against the force of the spring 90, and pulling thepoppet valve 64 to the left, seating thevalve 64 adjacent the opening 75, thereby closing off thepassage 66 and its communication via the-chamber 63 with thechamber 76 and thesupply passage 77. Hence, the air supply to themotor rotor 98 is cutoff and the rotation of thetool drive connector 216 is stopped. Thevalve 64 is held in seated position by high pressure in the chamber 61, and the high pressure in thechamber 87 is reduced by air escaping through themotor 98 and theexhaust outlet 114, which allows the valve means 139 to close and thebellows 126 to return to starting preload position. After themotor rotor 98 is stopped by the seating of thevalve 64, thevalve button 36 is released. High pressure air in the chamber 61 is released through the bleed plug and the radial ports 72 into thechamber 77, then through themotor rotor 98 and theexhaust outlet 114, allowing the spring 88 to return thevalve 64 to its original position. It should be noted that preloading, although not essential to the operation of the control and monitoring circuit, provides a conveniently variable means of regulating the rotational movement of theroller carrier 148 and the ring gear 152 (FIGS. 2a and 3) by limiting the displacement of thebellows 126. The mechanical force exerted against thebellows 126 is balanced by the air pressure within thebellows 126 at the time the maximum torque output, as preset by the adjustable valve means 139, is reached. A pressuremonitoring means, such as thegage 151, may be provided to allow observation and/or recording of both the preload pressure andthe output torque pressure developed within the control circuit. This output torque pressure will be an accurate measure of the torque pro duced at the squaredrive tool connector 216.

FIGURES 5-9 EMBODIMENT The alternate embodiment of apower tool assembly 220 shown in FIGS. 59 includes atransducer section 222 in lieu of thebellows 126, thecam spline member 130, theramps 140, therollers 144, and thecam follower 148. In this arrangement, the ring gear 224 (FIG. 6) of the firstplanetary unit 226 is secured to a wall of theplanetary section 18 by a fixedpin member 228. Thering gear 230 of a secondplanetary unit 232 is rotatably mounted within acylindrical bearing member 233 secured in thetransducer section 222, meshing with pinion gears 234 onbearings 236 aroundpinion shafts 238 supported by acarrier 240. The pinion gears 234 also mesh with a sun gear splines 242 formed on anextended end 244 of thecarrier 246 of the firstplanetary unit 226. Splines 248 are formed on an inner surface of thecarrier 240 to drivingly connect withsplines 250 formed on theoutput shaft 252. Thecarrier 240 is supported inbearings 253 retained in the outer shell 254 of thehead section 20 by aretainer ring 255.

Acylindrical spacer member 256 supports bearings 257 for the firstplanetary carrier 246 and is mounted within the outer shell 254 of thehead section 20 between oppositely disposed end faces of the bearingmember 233 and thefirst ring member 224.

An arcuate pocket 258 (FIG. 7) is formed in part on the outer periphery of thesecond ring gear 230, and in part in the adjacent cylindrical ringgear bearing member 233 secured within thetransducer section 222. Ashoe 260, having anarcuate seating surface 262 formed thereon, is slidably mounted in thearcuate pocket 258. A flat side orend face 264 is formed on theshoe 260 for at times abutting against bothrespective edges 266 and 268 (FIG. 7) of thering gear 230 and the fixedbearing member 233. A transverse groove orslot 270 is formed on the side of theshoe 260 opposite theflat side 264, suitable for the seating thereagainst of an end of atorque link member 272. Thetorque link member 272 extends through a tangentially extendingopening 274 formed in thetransducer section 222, abutting against adisc 276 slidably mounted in achamber 278. A bellows 280 is mounted in thechamber 278 intermediate thedisc 276 and anend cover 282, the latter being secured to thetransducer section 222 bybolts 284, and the open end of thebellows 280 being sealed by an O-ring seal 285 mounted in agroove 287 formed in theend cover 282. Aport 286 formed in theend cover 282 communicates between the interior of thebellows 280 and anoutlet passage 288 formed in theend cover 282.

In operation, as torque builds up under load at thetool drive connector 216, thesecond ring gear 230 is caused to rotate against the force of thebellows 280, moving theshoe 260, thetorque link member 272 anddisc 276 to the right as illustrated in FIG. 9, compressing thebellows 280 and providng a pressure change in theoutlet passage 288 which may be transmitted to any suitable pressure-actuated means, such as the valve means 139 of FIG. 2a, to cut off the supply of air to themotor rotor 98 as explained above.

The inherent springiness of thebellows 280 will return thedisc 276, thetorque link member 272 and theshoe 260 to the respective positions illustrated in FIG. 7 once the rotation of thetool drive connector 216 is stopped.

FIGURE 10 EMBODIMENT FIG. 10 illustrates an alternate embodiment of thetransducer section 222 including a pressure-sensing load cell 290 adjacent thedisc 276, in lieu of the bellows of the FIG. 7 structure. It should be noted that anarcuate pocket 292 is included which is substantially shorter than thearcuate pocket 258 of FIG. 7. Anend cover 294, secured to thetransducer section 222 bybolts 296, has anoutlet opening 298 formed therein suitable for the extension therethrough of a plurality ofelectrical conductors 300. This arrangement provides a signal-generating means involving a minimum of movement of thering gear 230, theshoe 260, thetorque link member 272, and thedisc 276.

FIGURE 11 EMBODIMENT FIG. 11 illustrates an alternate embodiment of the valving portion of thehandle section 12 which may be used in conjunction with the load cell arrangement of FIG. 10. In this structure, asolenoid 302 is mounted in thechamber 86 and has anaxial passage 303 formed therein for the slidable mounting therein of the poppet valve stem 67 in lieu of the piston 84 illustrated in FIG. 2b, and the signal is communicated thereto vialeads 304 rather than by thefluid pressure inlet 94 and thechamber 87 associated with the piston 84. Aspring 306 is mounted intermediate afixed wall 308 and theadjacent face 310 of thepoppet valve 64. Once the torque build-up signal is transmitted via theleads 304 through suitable amplification and electrical interface means to thesolenoid 302, the latter is energized and pulls the valve stem 67 farther into theaxial passage 303, against the force of thespring 306, thereby pulling thepoppet valve 64 past thepassage 66 to thus cut off the air supply to themotor supply passage 77.

It should be apparent that the invention provides an improved torque-controlled rotary power tool wherein a rotatable planetary ring gear and an adjacent transducer section combine to efficiently control and/or provide a means of continuously measuring output torque in proportion to the pressure developed on the transducer by rotation of the ring gear as it reacts to operational output torque.

vWhile several embodiments of the invention have been shown and described, other modifications thereof are possible.

I claim: 1. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, at least one planetary unit including a ring gear rotatably mounted in said housing, a sun gear operatively connected to and driven by said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, a bellows unit operatively connected between said ring gear and a fixed wall of said housing and having a predetermined. initial internal pressure, said ring gear rotatably reacting to increasing output torque on said rotary output means to increase said internal pressure of said bellows unit, and signal means responsive to said increased pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

2. The rotary power tool described in claim 1, and an indicating means operatively connected to said bellows unit, said internal pressure of said bellows unit being continuously monitored by said indicating means.

3. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, at least one planetary unit including a ring gear rotatably mounted in said housing, a sun gear formed on said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, ramp means splined to said housing, roller means mounted on said ramp means and operatively connected to said ring gear so as to be caused to roll along said ramp means in response to rotary motion of said ring gear, pressure-reacting means mounted intermediate said ramp means and a fixed wall of said housing, said ring gear rotatably reacting to increasing output torque on said rotary output means to axially actuate said ramp means through said roller means to increase the pressure of said pressure-reacting means, and signal means responsive to said increased pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

4. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, at least one planetary unit including a ring gear rotatably mounted in said housing, a sun gear formed on said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, an arcuate pocket formed in said ring gear, a shoe having a seat formed in a face thereof, a torque-link member abutted against said seat and extending therefrom for converting the rotary motion of said ring gear to tangential motion, pressure-reacting means mounted intermediate said torque-link member and a fixed wall of said housing, said ring gear rotatably reacting to increasing output torque on said rotary output means to actuate said torque-link member via said pocket and shoe to increase the pressure of said pressure-reacting means, and signal means responsive to said increased pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

5. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of fluid therethrough, a motor shaft extending from said motor rotor, cam means operatively mounted in said housing, a plurality of bellows mounted intermediate said cam means and a fixed wall of said housing, at least one planetary unit including a ring gear formed on said cam means, a sun gear formed on said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, said ring gear rotatably reacting to the output torque on said rotary output means to cause said cam means to compress said bellows and increase said pressure thereof, and signal means responsive to said pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

6. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, an inlet port for receiving fluid from said source of fluid under pressure, passage means communicating between said inlet port and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, a cam follower rotatably mounted in said housing around said motor shaft, a cam spline member slidably mounted in said housing around said motor shaft, a plurality of bellows mounted intermediate said cam spline member and a fixed wall of said housing and having a predetermined initial internal pressure, at least one arcuate ramp formed on said cam spline member, at least one roller rotatably mounted on said cam follower and positioned on said at least one arcuate ramp, a first planetary ring gear formed on said cam follower, a first sun gear formed on said motor shaft, a first carrier member, a first plurality of pinion gears rotatably mounted on said first carrier member and meshing with said first sun and ring gears, a second sun gear formed on said first carrier member, a second ring gear secured to said housing, a second carrier member, a second plurality of pinion gears rotatably mounted on said second carrier member and meshing with said second sun and ring gears, rotary output means operatively connected to said second carrier member, said first ring gear rotatably reacting to increasing output torque on said rotary output means to rotate said cam follower and said at least one roller to roll said roller toward the high point of said at least one ramp and thereby force said cam spline member to move axially to compress said bellows and increase said internal pressure thereof, and signal means responsive to said internal pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

7. The rotary power tool described inclaim 6, wherein said signal means includes second valve means for providing a fluid signal to close said first-mentioned valve means.

8. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, an inlet port for receiving fluid from said source of fluid under pressure, passage means communicating between said inlet port and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, a first planetary unit including a first ring gear secured to said housing, a first sun gear formed on said motor shaft, a first carrier member, and a first plurality of pinion gears rotatably mounted on said first carrier member and meshing with said first sun and ring gears, a second planetary unit including a second sun gear formed on said first carrier member, a second ring gear rotatably mounted in said housing, a second carrier member, and a second plurality of pinion gears rotatably mounted on said second carrier member and meshing with said second sun and ring gears, rotary output means operatively connected to said second carrier member, linkage means operatively connected for tangential movement with said second ring gear, and-a bellows unit mounted intermediate said linkage means and a fixed wall of said housing and having a predetermined initial internal pressure, said first ring gear rotatably reacting to increasing output torque on said rotary output means to tangentially move said linkage means to compress said bellows and increase said internal pressure thereof, and signal means responsive to said internal pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

9. The rotary power tool described inclaim 8, wherein said signal means includes second valve means for providing a fluid signal to close said first-mentioned valve means.

10. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, an inlet port for receiving fluid from said source of fluid under pressure, passage means communicating between said inlet port and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, at first planetary unit including a first ring gear secured to said housing, a first sun gear formed on said motor shaft, a first carrier member, and a first plurality of pinion gears rotatably mounted on said first carrier member and meshing with said first sun and ring gears, 21 second planetary unit including a second sun gear formed on said first carrier member, a second ring gear rotatably mounted in said housing, a second carrier member, and a second plurality of pinion gears rotatably mounted on said second carrier member and meshing with said second sun and ring gears, rotary output means operatively connected for tangential movement with said second ring gear, and a pressure-sensing load cell mounted intermediate said linkage means and a fixed wall of said housing, said first ring gear rotatably reacting to increasing output torque on said rotary output means to tangentially move said linkage means to apply pressure to said pressuresensing load cell, and signal means responsive to said pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

11. The rotary power tool described inclaim 10, wherein said signal means includes a solenoid and means for providing an electrical signal to cause said solenoid to close said valve means.

"H650 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 834,467 Dated September 10, 1974 Inventor (S) John R. Fuchs It is certified that error appears in the above-identified patent and that said' Letters Patent are hereby corrected as shown below:

Column 1, line 37, after "ring" insert gear line 58, change "compresa" to compress Column 3, line 43, change "112" to 122 Coluinn 4, line 22, change "164" to 162 Column 5, line 45, change "104" to 140Column 7, line 21, change "providng" to providing Signed and sealed this 3rd day of December 1974.

(SEAL) Attest: I

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents

Claims (11)

1. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, at least one planetary unit including a ring gear rotatably mounted in said housing, a sun gear operatively connected to and driven by said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, a bellows unit operatively connected between said ring gear and a fixed wall of said housing and having a predetermined initial internal pressure, said ring gear rotatably reacting to increasing output torque on said rotary output means to increase said internal pressure of said bellows unit, and signal means responsive to said increased pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

2. The rotary power tool described in claim 1, and an indicating means operatively connected to said bellows unit, said internal pressure of said bellows unit being continuously monitored by said indicating means.

3. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, at least one planetary unit including a ring gear rotatably mounted in said housing, a sun gear formed on said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, ramp means splined to said housing, roller means mounted on said ramp means and operatively connected to said ring gear so as to be caused to roll along said ramp means in response to rotary motion of said ring gear, pressure-reacting means mounted intermediate said ramp means and a fixed wall of said housing, said ring gear rotatably reacting to increasing output torque on said rotary output means to axially actuate said ramp means through said roller means to increase the pressure of said pressure-reacting means, and signal means responsive to said increased pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

4. A rotaRy power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, at least one planetary unit including a ring gear rotatably mounted in said housing, a sun gear formed on said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, an arcuate pocket formed in said ring gear, a shoe having a seat formed in a face thereof, a torque-link member abutted against said seat and extending therefrom for converting the rotary motion of said ring gear to tangential motion, pressure-reacting means mounted intermediate said torque-link member and a fixed wall of said housing, said ring gear rotatably reacting to increasing output torque on said rotary output means to actuate said torque-link member via said pocket and shoe to increase the pressure of said pressure-reacting means, and signal means responsive to said increased pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

5. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, passage means communicating between said source of fluid and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of fluid therethrough, a motor shaft extending from said motor rotor, cam means operatively mounted in said housing, a plurality of bellows mounted intermediate said cam means and a fixed wall of said housing, at least one planetary unit including a ring gear formed on said cam means, a sun gear formed on said motor shaft, a carrier member, a plurality of pinion gears rotatably mounted on said carrier member and meshing with said sun and ring gears, rotary output means operatively connected to said carrier member, said ring gear rotatably reacting to the output torque on said rotary output means to cause said cam means to compress said bellows and increase said pressure thereof, and signal means responsive to said pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

6. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, an inlet port for receiving fluid from said source of fluid under pressure, passage means communicating between said inlet port and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, a cam follower rotatably mounted in said housing around said motor shaft, a cam spline member slidably mounted in said housing around said motor shaft, a plurality of bellows mounted intermediate said cam spline member and a fixed wall of said housing and having a predetermined initial internal pressure, at least one arcuate ramp formed on said cam spline member, at least one roller rotatably mounted on said cam follower and positioned on said at least one arcuate ramp, a first planetary ring gear formed on said cam follower, a first sun gear formed on said motor shaft, a first carrier member, a first plurality of pinion gears rotatably mounted on said first carrier member and meshing with said first sun and ring gears, a second sun gear formed on said first carrier member, a second ring gear secured to said housing, a second carrier member, a second plurality of pinion gears rotatably mounted on said second carrier member and meshing with said second sun and Ring gears, rotary output means operatively connected to said second carrier member, said first ring gear rotatably reacting to increasing output torque on said rotary output means to rotate said cam follower and said at least one roller to roll said roller toward the high point of said at least one ramp and thereby force said cam spline member to move axially to compress said bellows and increase said internal pressure thereof, and signal means responsive to said internal pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

7. The rotary power tool described in claim 6, wherein said signal means includes second valve means for providing a fluid signal to close said first-mentioned valve means.

8. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, an inlet port for receiving fluid from said source of fluid under pressure, passage means communicating between said inlet port and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, a first planetary unit including a first ring gear secured to said housing, a first sun gear formed on said motor shaft, a first carrier member, and a first plurality of pinion gears rotatably mounted on said first carrier member and meshing with said first sun and ring gears, a second planetary unit including a second sun gear formed on said first carrier member, a second ring gear rotatably mounted in said housing, a second carrier member, and a second plurality of pinion gears rotatably mounted on said second carrier member and meshing with said second sun and ring gears, rotary output means operatively connected to said second carrier member, linkage means operatively connected for tangential movement with said second ring gear, and a bellows unit mounted intermediate said linkage means and a fixed wall of said housing and having a predetermined initial internal pressure, said first ring gear rotatably reacting to increasing output torque on said rotary output means to tangentially move said linkage means to compress said bellows and increase said internal pressure thereof, and signal means responsive to said internal pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

9. The rotary power tool described in claim 8, wherein said signal means includes second valve means for providing a fluid signal to close said first-mentioned valve means.

10. A rotary power tool for use with a source of fluid under pressure, said rotary power tool comprising a housing including a fluid-actuated motor rotor, an inlet port for receiving fluid from said source of fluid under pressure, passage means communicating between said inlet port and said motor rotor, valve means operatively mounted in said passage means for controlling the flow of said fluid therethrough, a motor shaft extending from said motor rotor, a first planetary unit including a first ring gear secured to said housing, a first sun gear formed on said motor shaft, a first carrier member, and a first plurality of pinion gears rotatably mounted on said first carrier member and meshing with said first sun and ring gears, a second planetary unit including a second sun gear formed on said first carrier member, a second ring gear rotatably mounted in said housing, a second carrier member, and a second plurality of pinion gears rotatably mounted on said second carrier member and meshing with said second sun and ring gears, rotary output means operatively connected for tangential movement with said second ring gear, and a pressure-sensing load cell mounted intermediate said linkage means and a fixed wall of said housing, said first ring gear rotatably reacting to increasing output torque on said rotary outpUt means to tangentially move said linkage means to apply pressure to said pressure-sensing load cell, and signal means responsive to said pressure to cause said valve means to cut off said fluid flow through said passage means upon the attainment of a predetermined output torque.

11. The rotary power tool described in claim 10, wherein said signal means includes a solenoid and means for providing an electrical signal to cause said solenoid to close said valve means.

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