US3593830A - Automatic throttle torque-responsive power tool - Google Patents
Automatic throttle torque-responsive power tool Download PDFInfo
- Publication number
- US3593830A US3593830A US820940A US3593830DA US3593830A US 3593830 A US3593830 A US 3593830A US 820940 A US820940 A US 820940A US 3593830D A US3593830D A US 3593830DA US 3593830 A US3593830 A US 3593830A
- Authority
- US
- United States
- Prior art keywords
- clutch
- spindle
- motor
- spring
- tool
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B23/00—Details of, or accessories for, spanners, wrenches, screwdrivers
- B25B23/14—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers
- B25B23/145—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for fluid operated wrenches or screwdrivers
Definitions
- ABSTRACT A fluid-operated power screwdriver having 3 us. C1 192/150, torque-Opening Clumh and a throttle which is pened y he 1921.034, 192/56 R, 81/524 operator pressing the screwdriver against a fastener and Int. Cl HM 43/20 closed in response to the opening of the clutch
- the opening Field 0! Search H 192/.034, of the clutch moves a control sleeve to a locking position 150 whereby the throttle is allowed to close
- a power-operated screwdriver or the like with a torque-controlled clutch which automatically disconnects the tool spindle from its motor when the torque load on the spindle rises to a predetermined value.
- a compressed airoperated screwdriver with a throttle which automatically opens to start the screwdriver motor when it is pressed against a screw and closes to stop the screwdriver when it is withdrawn from a screw.
- the principal object of this invention is to combine a torque-controlled clutch with a motor starting and stopping means in a novel manner whereby a tool using the combination will stop its motor and simultaneously disconnect the motor from the spindle or bit when the torque load on the spindle rises to a predetermined value.
- Another object is to combine a torque-responsive clutch and a control spring with a motor throttle in a manner so that the control spring moves the throttle between motor starting and stop ing positions and a lockout means renders the control spring inoperative to hold the throttle open when the clutch opens.
- the objects of this invention are carried out in a compressed-air-operated screwdriver by mounting a torque'opening axially moving clutch between the motor and screwdriver bit so that the clutch automatically opens when the torque load reaches a predetermined magnitude and by interconnecting a control spring means to a throttle for the motor so that the throttle opens when the tool is started during initial engagement of the screwdriver with a fastener to be driven.
- the control spring means is axially moved to an inoperative position wherein the throttle can close.
- FIG. I is an elevational view with parts broken away of a power screwdriver containing the invention.
- FIG. 2 is a fragmentary section on an enlarged scale of the screwdriver of FIG. 1 showing the throttle valve in its open position;
- FIG. 3 is a fragmentary section similar to FIG. 2 and showing the clutch in its open position with the throttle valve closed;
- FIG. 4 is a fragmentary section similar to FIGS. 2 and 3 and showing the clutch in its final position with the throttle valve closed;
- FIG. 5 is a section taken on line 5-5 of FIG. 3.
- the power'operated screwdriver 1 shown in the drawings includes a hollow cylindrical casing formed by a rear portion 2 and a front portion 3 threadedly connected to the rear portion 2.
- the rear casing portion 2 houses a conventional pneumatic motor 4 driving an output shaft 5 through a set of reduction gears 6.
- the output shaft 5 is mounted at its front end on a bearing 7 carried by the front end of the rear casing portion 2.
- the front casing portion 3 also includes a reduced-diameter nose 8 on its front end.
- the nose 8 contains a conventional tool holder or chuck 9 which is rotatively mounted in a journal bearing I0 in the rear end of the nose 8.
- the tool-holding chuck 9 contains a polygonal socket 11 adapted to receive various types of tools, fastener-engaging spindles or tips such as the screwdriver tip 12. All of the foregoing structure is conventional and usually found in power-operated screwdrivers.
- the torque-release clutch mechanism of this invention provides a drive connection between the output shaft 5 and the tool-holding chuck 9. It includes a short splined drive shaft l4 which extends axially slidably into the rear part of the front casing portion 3 and is seated in a cooperating splined socket socket in the output shaft 5, thus providing an axiaI-slidable drive connection between the drive shaft 14 and the motor.
- the front end of the drive shaft I4 includes a rear clutch plate 15 containing a forwardly opening axial bore I6.
- the rear end of a clutch shaft I7 is rotatably mounted in the axial bore 16 by ball bearings 18 seated in cooperating grooves.
- the clutch shaft [7 is integral with the chuck 9.
- a front clutch plate 22 is slidably keyed on the clutch shaft [7 in front of the rear clutch plate [5 by several key balls 23 engaging longitudinal grooves.
- the rear clutch plate I5 rotates on the ball bearings I8 when the clutch plates 15 and 22 are open; thus the ball bearings 18 prevent the rear clutch plate IS from sliding relative to the clutch shaft 17.
- the rear and front clutch plates 15 and 22 are intercon nected together by a series of circumfe rentially interengaging cam teeth 24 formed in the adjacent faces of both clutch plates and providing a driving connection between the two clutch plates 15 and 22 so long as the plates are pressed together and the torque load carried by the clutch plates is not sufficient to disengage them.
- the two clutch plates I5 and 22 and the cam teeth 24 form a cam-thrust" clutch 25.
- the front clutch plate 22 is biased against the rear clutch plate 15 by a heavy compression spring 28 which is engaged at its front end by an adjustment mechanism for varying the compression load on the spring 28.
- the compression force exerted by the heavy spring 28 tends to keep the cam teeth 24 engaged during the transmission of a torque load through the "camthrust" clutch 25.
- the cam teeth 24 disengage and cam-thrust the front clutch plate 22 forwardly, against the spring 28, thus releasing the "cam-thrust” clutch 25.
- the magnitude of torque at which the cam teeth 24 disengage is changed by varying the compression load on the spring 28.
- the torque value at which the "cam-thrust"clutch 25 will release rises as the load on the spring 28 increases and drops as the spring load decreases.
- the adjustment mechanism for the spring 28 includes a nut 29 threaded on the front end of the clutch shaft 17.
- a valve control sleeve 30 is slidably keyed on the clutch shaft 17 in front of the front clutch plate 22 by a crossbar 3
- the control sleeve 30 is biased rearwardly against the front clutch plate 22 by a light spring 34 extending between the front of the control sleeve 30 and a shoulder 35 formed on the clutch shaft 17.
- the means for locking the control sleeve 30 in its forward osition shown in FIG. 4 includes a group of lock balls 37 carried in radial holes in the clutch shaft 17 and biased outwardly into an annular groove 38 formed in the interior of the control sleeve 30.
- the lock balls 37 are biased radially outward by a conical cam 40 carried on the rear end of the screwdriver tip I2 and sliding in the clutch shaft 17 for a limited travel.
- the conical cam 40 is moved rearwardly relative to the clutch shaft l7, to bias the lock balls 37 outwardly, by the relative forward movement of the screwdriver tip I2 in the socket 11 when the screwdriver tip 12 is pressed axially against a fastener by an operator.
- a small spring 41 urges the screwdriver tip 12 forwardly to unlock the control sleeve 30 when the axial force against the screwdriver tip I2 is released.
- the cam 40 initially engages the lock balls 37 and stops moving rearward since the lock balls 37 cannot move outwardly. Later, when the clutch 25 opens and the control sleeve 30 moves forward, the lock balls 37 move outward into the annular groove 38 as shown in FIG. 3 and the conical cam 40 moves between the lock balls 37 causing them to lock the control sleeve 30 in the forward position shown in FIG. 4.
- the tool is fed pneumatic fluid pressure through a supply hose attached to a fitting 45 mounted on the rear casing portion 2 of the tool.
- the pneumatic pressure flows from the fitting to a throttle valve 46 (shown as a ball valve) which controls the admission of the pressure to a motor supply passage 47.
- a throttle valve 46 shown as a ball valve
- pneumatic pressure flows past the valve 46 to the motor supply passage 47 and then to the motor 4.
- the flow of pneumatic pressure fluid into the passage 47 is stopped by moving the valve 46 forwardly to its seated position, as shown in FIG. 3.
- the fluid pressure in the fitting 45 acts as an air spring to hold the valve 46 in its closed position until such time that it is forced rearwardly to its open position.
- the throttle valve 46 is opened by means of a push rod 48 which slides in an axial passage extending from the crossbar 31 through the clutch shaft l7, the drive shaft 14, the output shaft 5, the reduction gears 6 and the motor 4 to engagement with the throttle valve 46.
- the length of the pushrod 48 is dimensioned to allow the throttle valve 46 to close when the axial force on the screwdriver tip 12 is relaxed and to force the throttle valve 46 open when the screwdriver tip I2 is initially forced against a fastener, as shown in FIG. 2.
- the tip I2 is pressed rearwardly against the lock balls 37 and the clutch shaft 17 is moved rearwardly until the rear clutch plate abuts the bearing 7. This is the rearward movement that opens the valve 46.
- the screwdriver I Prior to the start of operation, the screwdriver I is in the condition shown in FIG. I.
- the "cam-thrustclutch 25 is closed and the control sleeve 30 is unlocked.
- the conical cam 40 is withdrawn from the lock balls 37, the clutch shaft 17 is in its forward position, the lock balls 37 are not biased radially outward, and the push rod 48 is allowed to move forward whereby the throttle valve 46 is closed; thus the motor 4 of the screwdriver I is stopped.
- the nut 22 Before using the screwdriver I. the nut 22 is turned until the heavy spring 28 is loaded to the desired magnitude, which determines the predetermined magnitude of torque under which the "cam-thrust" clutch 15 will open.
- the screwdriver spindle or tip 12 is placed against the head of a fastener and the screwdriver I is pressed axially forward to force the tool-holding clutch shaft 17 axially rearward in the casing 2.
- the rearward movement of the clutch shaft I7 carries the control sleeve 30 and crossbar 3
- the opening of the throttle valve 46 admits fluid pressure to the passage 47 and thence to the operating motor 4, which begins to drive the drive shaft 14. It will be noted that the light spring 34 must have sufficient strength to open the valve 46 without collapsing.
- cam teeth 24 reengage and allow the front clutch plate 22 under the biasing force of the spring 28, to return to its rearward seated position, as shown in FIG. 4.
- the stopping of the tool motor 4 signals the operator that the fastener is tightened properly and he removes the screwdriver I from the fastener, thus allowing the screwdriver tip I2 to move axially forward.
- the forward movement of the tip [2 is accompanied by a corresponding relative forward movement of the conical cam 40 away from the lock balls 37, caused by the spring 4
- the lock balls 37 move radially inward and the control sleeve 30 is unlocked resulting in the screwdriver I returning to the condition shown in FIG.
- a power-operated tool comprising:
- control means having alternate positions and controlling said supply means so that in one position it prevents said energy from being supplied to said motor, and in its other position, it allows said energy to flow to said motor, said control means being normally in said one position and includin biasing means urging said control means to said one position,
- a tool spindle adapted to be connected to a workpiece for applying a torque load to the workpiece and operative, when pressed against the workpiece, to move said control means to its other position;
- a torque-responsive clutch which is normally closed to interconnect said spindle to said motor, said clutch being operative, in response to a predetermined torque load on said spindle, to open wherein said motor can rotate relative to said spindle, said clutch including a clutch member that moves axially when said clutch opens; spring located between said spindle and said control means and operative, in its normal position, when said clutch is closed and said spindle is pressed against a workpiece, to transmit force from said spindle to said control means to urge and hold said control means in its other position, said clutch member being operative, when moving axially during the opening of said clutch, to cause said spring to yield to an inoperative position wherein said spring no longer holds said control means in its other position; and
- lock means movable in response to the opening of said clutch to hold said spring in said inoperative position wherein said control means can return to said one position preventing said motor-driving energy from flowing to said motor.
- said lock means is operative, in response to the withdrawal of the spindle from the workpiece, to unlock said spring and allow it to return to its normal position.
- a fluid-operated rotary tool comprising:
- a housing including a fluid-operated rotary motor
- a throttle valve in said passage movable between alternate positions closing and opening said passage, said throttle valve being normally closed and including biasing means urging said throttle valve to a closed position;
- a tool spindle adapted to be connected to a workpiece for applying a torque load to the workpiece and operative, when pressed against the workpiece, to move said throttle valve to its open position;
- a torque-responsive clutch interconnecting said spindle to said motor, said clutch being operative, in response to a predetermined torque load on said spindle, to open and disconnect said spindle from said motor, said clutch ineluding a clutch member that moves axially when said clutch opens;
- a spring located between said spindle and said throttle valve and operative in its normal position, when said clutch is closed and said spindle is pressed against the workpiece, to transmit force from said spindle to said throttle valve to hold said throttle valve open during the operation of the tool, said clutch member being operative, when moving axially during the opening of said clutch, to cause said spring to yield to an inoperative position wherein said spring no longer holds said throttle valve open;
- lock means cooperating with said clutch and movable to a position in response to the opening of said clutch wherein it locks and holds said spring in said inoperative position whereby said biasing means moves said throttle valve to its closed position preventing the power fluid from driving said motor.
- said lock means is operative, in response to the withdrawal of said spindle from the workpiece, to unlock said spring and allow it to return it to its normal position.
- said clutch member acts upon and compresses said spring in an axial direction as said clutch opens.
- said lock means includes an intermediate member interposed betwecn said spring and said clutch member and a detent means operative to latch said intermediate member in the inoperative position of said spring.
- said detent means is actuated by axial force applied to the spindle as the result of the operator pressing the spindle against the workpiece.
- said intermediate member is an axially sliding sleeve engaging said clutch member and movable axially with said clutch member.
- a l'luid'operated rotary tool comprising:
- a housing including a fluid-operated rotary motor
- a throttle valve in said passage movable between alternate positions closing and opening said passage and including biasing means urging said throttle valve to a closed position
- throttle operator means mounted in said housing and operable by an operator for moving said throttle valve to an open position to start said motor
- a tool spindle adapted to be connected to a workpiece for applying a torque load to the workpiece
- a torque-responsive clutch interconnecting said spindle to said motor, said clutch being operative, in response to a predetermined torque load on said spindle, to progressively open and disconnect said spindle from said motor, said clutch including a clutch member that moves progressively axially as said clutch opens;
- control means operative in response to the progressive axial movement of said clutch member during the opening of said clutch, to progressively close said throttle valve in step with the axial movement of said clutch member whereby said motor is progressively stopped as said clutch progressively opens.
- said control means includes spring means which normally holds said throttle valve in its open position after being moved to the open position by an operator.
- said spring means is moved to its inoperative position, wherein it no longer holds said throttle valve open, by the movement of said clutch to its open position.
- lock means to hold said spring means in its inoperative position after being moved to said inoperative position by said clutch.
- said throttle valve is mechanically connected to an intermediate member disposed between said spring means and said clutch member with said spring means urging said intermediate member axially against said clutch member and said clutch member moving said intermediate member axially to allow said throttle valve to close as said clutch opens.
- said lock means latches said intermediate member in the closed position of said throttle valve after said clutch opens.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US82094069A | 1969-05-01 | 1969-05-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3593830A true US3593830A (en) | 1971-07-20 |
Family
ID=25232102
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US820940A Expired - Lifetime US3593830A (en) | 1969-05-01 | 1969-05-01 | Automatic throttle torque-responsive power tool |
Country Status (4)
Country | Link |
---|---|
US (1) | US3593830A (fr) |
BE (1) | BE749857A (fr) |
DE (1) | DE2021311A1 (fr) |
FR (1) | FR2046128A5 (fr) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4088197A (en) * | 1975-02-08 | 1978-05-09 | Robert Bosch Gmbh | Power tool |
US4576270A (en) * | 1983-02-28 | 1986-03-18 | The Aro Corporation | Torque control and fluid shutoff mechanism for a fluid operated tool |
US4641551A (en) * | 1983-12-27 | 1987-02-10 | Hall Surgical, Division Of Zimmer, Inc. | Apparatus for translating rotational motion and torque |
US5101947A (en) * | 1989-04-19 | 1992-04-07 | Metabowerke Gmbh & Co. | Connectable drive for a screwdriver spindle |
US6263742B1 (en) * | 1997-11-17 | 2001-07-24 | Serac Group | Method of controlling a screwing spindle |
CN104100690A (zh) * | 2013-04-12 | 2014-10-15 | 斯泰必鲁斯有限公司 | 具有过载保护的驱动装置 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2964151A (en) * | 1958-12-01 | 1960-12-13 | Reed Roller Bit Co | Automatic supply and shut off of motive fluid for torque tool |
US3187860A (en) * | 1963-01-24 | 1965-06-08 | Chicago Pneumatic Tool Co | Portable nut runner having automatic speed change and automatic shut-off |
US3275116A (en) * | 1964-10-12 | 1966-09-27 | Airetool Mfg Company | Air powered tool with overload cutoff |
US3289715A (en) * | 1964-03-19 | 1966-12-06 | Aro Corp | Automatic shut-off tool |
US3515251A (en) * | 1969-04-14 | 1970-06-02 | Ingersoll Rand Co | Torque release and shutoff device for rotary tools |
-
1969
- 1969-05-01 US US820940A patent/US3593830A/en not_active Expired - Lifetime
-
1970
- 1970-02-16 FR FR7005468A patent/FR2046128A5/fr not_active Expired
- 1970-04-30 DE DE19702021311 patent/DE2021311A1/de active Pending
- 1970-04-30 BE BE749857D patent/BE749857A/fr unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2964151A (en) * | 1958-12-01 | 1960-12-13 | Reed Roller Bit Co | Automatic supply and shut off of motive fluid for torque tool |
US3187860A (en) * | 1963-01-24 | 1965-06-08 | Chicago Pneumatic Tool Co | Portable nut runner having automatic speed change and automatic shut-off |
US3289715A (en) * | 1964-03-19 | 1966-12-06 | Aro Corp | Automatic shut-off tool |
US3275116A (en) * | 1964-10-12 | 1966-09-27 | Airetool Mfg Company | Air powered tool with overload cutoff |
US3515251A (en) * | 1969-04-14 | 1970-06-02 | Ingersoll Rand Co | Torque release and shutoff device for rotary tools |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4088197A (en) * | 1975-02-08 | 1978-05-09 | Robert Bosch Gmbh | Power tool |
US4576270A (en) * | 1983-02-28 | 1986-03-18 | The Aro Corporation | Torque control and fluid shutoff mechanism for a fluid operated tool |
US4641551A (en) * | 1983-12-27 | 1987-02-10 | Hall Surgical, Division Of Zimmer, Inc. | Apparatus for translating rotational motion and torque |
US5101947A (en) * | 1989-04-19 | 1992-04-07 | Metabowerke Gmbh & Co. | Connectable drive for a screwdriver spindle |
US6263742B1 (en) * | 1997-11-17 | 2001-07-24 | Serac Group | Method of controlling a screwing spindle |
CN104100690A (zh) * | 2013-04-12 | 2014-10-15 | 斯泰必鲁斯有限公司 | 具有过载保护的驱动装置 |
US20140309041A1 (en) * | 2013-04-12 | 2014-10-16 | Stabilus Gmbh | Drive device with overload protection |
EP2789869A3 (fr) * | 2013-04-12 | 2015-11-04 | Stabilus GmbH | Dispositif d'entraînement avec protection contre les surcharges |
US9500236B2 (en) * | 2013-04-12 | 2016-11-22 | Stabilus Gmbh | Drive device with overload protection |
Also Published As
Publication number | Publication date |
---|---|
FR2046128A5 (fr) | 1971-03-05 |
BE749857A (fr) | 1970-10-01 |
DE2021311A1 (de) | 1971-11-04 |
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