专利摘要:
A power nut runner with a torque responsive shut-off capacity comprises a housing (11, 12, 13), a rotation motor (10) connected to an output shaft (28) via a torque responsive release clutch (26) in which torque is transferred via a cam mechanism (31, 35, 36) between a driving clutch half (25) and a driven clutch half (27, 30, 39), and a spring (32) is arranged to bias and displace a first one of the clutch halves (27, 30, 39) towards the other in an engagement direction, a signal emitting release detecting sensor (46), and an activation element (40) arranged to be thrown off an abutting contact with the spring biassed clutch half (27, 30, 39) to reach an active position beyond its inactive low torque position as the spring biassed clutch half (27, 30, 39) is abruptly returned to its engagement position after an axial release movement.
公开号:US20010004940A1
申请号:US09/750,845
申请日:2000-12-28
公开日:2001-06-28
发明作者:Gunnar Hansson
申请人:Atlas Copco Tools AB;
IPC主号:B23Q11-04
专利说明:
[0001] The invention relates to a power nut runner of the type comprising a rotation motor for driving an output shaft via a torque responsive release clutch including a driving clutch half, a driven clutch half, and a cam mechanism for transferring torque between the driving clutch half and the driven clutch half, wherein a first one of the driving and driven clutch halves is axially moveable by the cam mechanism in a release direction, from an engagement position to a release position, a spring arranged to bias and displace the first clutch half in an engagement direction, and a clutch release detecting device co-operative with the movable first clutch half. [0001]
[0002] In prior art nut runners of the above type, described for instance in U.S. Pat. Nos. 4,838,364 and 5,201,374, there are provided clutch release detecting devices including an activation rod extending axially through the rotor of the motor. Since the activation rod is not rotationally locked to the rotor, there will always be a difference in speed between the rod and the rotor which inevitably results in a frictional wear of the rod. [0002]
[0003] Moreover, in most tools of this type there is employed a speed reduction gearing between the motor and the clutch, which means that there is also a difference in speed between the rotor and the activation rod support point on the clutch. This amplifies the problem of frictional wear of the rod, and despite an adequate surface hardening of the rod, there is still a problem with a limited service life of the device. [0003]
[0004] In U.S. Pat. No. 4,231,270, there is described a power screw driver in which a micro switch is actuated by one part of a torque limiting clutch provided between the ring gear of a planetary reduction gearing and the tool housing. This concept, however, is less advantageous in that the release detecting switch is activated by a clutch which is not an in-line clutch, i.e. the clutch does not transfer the driving torque. This results in a slower and less accurate release action and release detection. [0004]
[0005] In U.S. Pat. No. 3,608,686, there is described a torque responsive in-line clutch with an overload detecting micro-switch intended for preventing damage on machine tool parts by initiating disconnection of a drive motor. A disadvantage inherent in this device refers to an indistinct action of the switch due to a rather short and slow axial release movement of the clutch part. This results in a less accurate release detecting signal. Another disadvantage of this known device is the continuous sliding action between the stationary micro-switch arm and the rotating clutch, which inevitably results in a frictional wear of these parts. [0005]
[0006] A disadvantage also relating to the clutch operated switch shown in U.S. Pat. No. 4,231,270 resides in the fact that the release movement of the clutch is rather short and that the switch has to be activated somewhere during that movement. Due to this short activation movement, the switch has to be very carefully adjusted to ensure a proper activation. This makes the release detecting and power shut-off mechanism rather sensitive and less reliable. [0006]
[0007] The primary object of the invention is to accomplish a power nut runner by which the above mentioned problems are avoided by providing a torque transferring clutch with a release detecting device which provides a distinct and prompt power shut-off initiating movement. [0007]
[0008] Further objects and advantages of the invention will appear from the following specification and claims. [0008]
[0009] A preferred embodiment of the invention is below described in detail with reference to the accompanying drawing figures. [0009]
[0010] On the drawings: [0010]
[0011] FIG. 1 shows a side view, partly in section, of a power nut runner according to the invention. [0011]
[0012] FIG. 2[0012] a shows schematically and on a larger scale a longitudinal section through the torque release clutch and shut-off initiating mechanism of the power tool in FIG. 1 and illustrates the mechanism in a low torque condition.
[0013] FIG. 2[0013] b illustrates the mechanism in FIG. 2a in a release position.
[0014] FIG. 2[0014] c illustrates the mechanism in FIG. 2a in a shut-off initiating position.
[0015] FIG. 3[0015] a shows schematically and on a larger scale a fractional view of the torque transferring balls and clutch pockets in their low torque transferring positions.
[0016] FIG. 3[0016] b shows the view in FIG. 3a, but illustrates the beginning of the release displacement of the clutch.
[0017] FIG. 3[0017] c shows the view in FIG. 3a, but illustrates the fully released position of the clutch.
[0018] The power nut runner shown in FIG. 1 comprises a battery powered electric motor [0018] 10 controlled by a manually operated on/off switch (not shown) and an automatically operated shut off switch (not shown).
[0019] The nut runner further comprises a housing [0019] 11 divided into a forward section 12 and a rear section 13. In the rear section 13, there is located a double planetary type reduction gearing including a first stage 14 with a sun gear 15 rotated by the output spindle 16 of the motor 10, a number of planet wheels 17 journalled on a planet wheel carrier 18, and a ring gear 19 secured in the housing 11. A second stage 20 includes a sun gear 21 formed on the planet wheel carrier 18, a number of planet wheels 22 journalled on a planet wheel carrier 23 and engaging the ring gear 19 which, accordingly, is common to both gearing stages. As illustrated in FIG. 1, the planet wheel carrier 23 of the second stage 20 is connected via a coupling member 24 to a driving clutch half 25 of a torque responsive release clutch 26.
[0020] The release clutch [0020] 26 also comprises a driven clutch half 27 which is formed integrally with the output shaft 28 and the screw bit attachment 29 of the nut runner. The driven clutch half 27 includes an annular thrust element 30, a number of torque transferring balls 31, a bias spring 32 for pre-loading the thrust element 30 onto the balls 31, and an adjustable spring support 33. The latter is axially supported by a ring nut 34 threadingly engaging the output shaft 28. The thrust element 30 as well as the driving clutch half 25 are provided with pockets 35 and 36, respectively, for receiving the balls 31 and for transferring torque between the clutch halves 25 and 27, in a conventional way. The pockets 35, 36 are formed with slanted side walls which together with the balls 31 accomplish an axial displacement of the thrust element 30 as the clutch halves 25, 26 are rotationally displaced relative to each other at a certain predetermined torque load. See FIGS. 3a-c.
[0021] Moreover, between the driven clutch half [0021] 27 and the thrust element 30 there is provided a ball spline connection 38 for enabling a simultaneous torque transfer and axial displacement between the thrust element 30 and the driven clutch half 27.
[0022] The thrust element [0022] 30 is provided with a sleeve member 39 which extends rearwardly from the thrust element 30 into an abutting engagement with an activation element 40. The latter is made of steel and comprises a rearwardly extending sleeve portion 41 and a flange portion 42. The sleeve portion 41 is movably guided on an outer cylindrical surface 43 of the ring gear 19, and an inner part of the flange portion 42 is intended to be abuttingly engaged by the rear end of the sleeve member 39. A number of magnets 44 are mounted in a common plane and in a circle at the rear end of the forward housing section 12 and arranged to generate an attraction force on the flange portion 42 of the activation element 40.
[0023] In the rear housing section [0023] 13, there is mounted a shut-off switch 46 which is arranged to be activated by the activation element 40. Preferably, the shut-off switch 46 is of the non-contact Hall-element type which is triggered by the mere presence of the sleeve portion 41 of the activation element 40.
[0024] In operation of the nut runner, during the initial running down phase of a screw joint tightening process, the torque delivered by the motor [0024] 10 via the output spindle 17 is transferred through the reduction gearing stages 14, 20 and the coupling member 24 to the driving clutch half 25. Then, the torque is transferred via the balls 31 and the thrust element 30 to the output shaft 28 and further to the screw joint being tightened via the screw bit attachment 29.
[0025] Initially, the reaction torque from the screw joint is low enough not to make the balls [0025] 31 climb the slanted walls of the pockets 35, 36 in the thrust element 30 and the driving clutch half 25, respectively, against the bias load of the spring 32. At this stage of the tightening process, which is illustrated in FIG. 2a, the activation element 40 occupies its inactive position in which it is drawn against the end of the sleeve member 39 by the magnets 44.
[0026] As the reaction torque from the screw joint has increased to a certain level, the camming action between the slanted walls of the pockets [0026] 35, 36 and the balls 27 will make the thrust element 30 move axially (to the right in FIGS. 2a-c) against the bias load of the spring 32. This results in a subsequent movement of the sleeve member 39 as well as the activation element 40 under the action of the magnets 44 until the activation element 40 gets into contact with the magnets 44. This position is illustrated in FIG. 2b.
[0027] At continued rotation of the driving clutch half [0027] 25, each one of the balls 31 will climb up the slanted walls of the pockets 35, 36 in the driving clutch half 25 and the thrust element 30 and pass an apex before falling into the next pockets, in a way common to this type of clutch. However, when the balls 31 fall into the next pockets, the thrust element 30 is accelerated very abruptly by the force of the spring 32. This means that the thrust element 30, the sleeve member 39 and the activation element 40 are abruptly accelerated as well, and when the thrust element 30 and the sleeve member 39 are stopped as the balls 31 reach the bottoms of the new pockets, the activation element 40 will continue its movement, to the left in FIGS. 2a-c, as a result of its inertia, i.e. the kinetic energy gained during the return movement of the thrust element 30.
[0028] Now, the activation element [0028] 40 will reach its active position, beyond its inactive low torque position as shown in FIG. 2a, such that the sleeve portion 41 gets into a position opposite the sensor 46, thereby making the latter deliver a signal for initiating shut-off of the motor 10. See FIG. 2c.
[0029] After having been thrown backwards to its active switch triggering position, the activation element [0029] 40 returns immediately to its inactive position, as shown in FIG. 2a, by the attraction force of the magnets 44. In this position the activation element 40 re-assumes its abutting engagement with the sleeve member 39.
[0030] By arranging the activation element [0030] 40 freely movable in the re-engagement direction of the clutch there is obtained a distinct and extended activation movement of the activation element 40 such that the triggering of the shut-off initiating switch 46 distinctly and safely indicates that the clutch has been released and that the intended torque level has been obtained.
[0031] Although in the above described embodiment of the invention there is used a Hall-type switch for accomplishing a contact-less activation, the invention is not limited to this type of switch. However, a contact-less activation is preferred because it does not suffer from mechanical wear. [0031]
[0032] Neither is the invention limited to the use of magnets for biassing the activation element [0032] 40 towards the inactive position of the latter. Alternatively, some type of spring may be used. Magnets are preferred though, because they are not exposed fatigue stresses.
权利要求:
Claims (6)
[1" id="US-20010004940-A1-CLM-00001] 1. Power nut runner with a torque responsive power shut-off capacity, comprising a housing (11, 12, 13), a rotation motor (10), an output shaft (28), a torque responsive override clutch (26) for transferring torque from the motor (10) to the output shaft (28), said clutch (26) includes a driving clutch half (25), a driven clutch half (27, 30, 39), a cam mechanism (31, 35, 36) for transferring torque between the driving clutch half (25) and the driven clutch half (27, 30, 39), a first one of the clutch halves (27, 30, 39) is axially movable by the cam mechanism (31, 35, 36) in a release direction from an engagement position to a release position, and a spring (32) is arranged to bias and displace said first clutch half (27, 30, 39) towards said engagement position, and a clutch release detecting device (40, 46) co-operative with said first clutch half (27, 30, 39), characterized in that the clutch release detecting device (40, 46) comprises:
a signal emitting sensor (46) supported in the housing (11, 12, 13),
an activation element (40) freely movable between an inactive position and an active position in which it co-operates with the sensor (46),
a bias force delivering device (44) urging the activation element (40) towards an abutting engagement with said first clutch half (27, 30, 39) to occupy the inactive position as said first clutch half (27, 30, 39) occupies its engagement position,
wherein said activation element (40) is accellerated by said first clutch half (27, 30, 39) as the latter after release of said clutch reoccupies its engagement position, such that the activation element (40) is displaced by inertial forces to its active position for co-operation with the sensor (46) and accomplishing a power shut-off initiating signal.
[2" id="US-20010004940-A1-CLM-00002] 2. Power nut runner according to
claim 1 , wherein said activation element (40) is arranged to follow said first clutch half (27, 30, 39) during at least a part of said release movement and to be hit by said first clutch half (27, 30, 39) as the latter is returned by the force of the spring (32) toward its engagement position, whereby the activation element (40) receives an impact energy effective to move the activation element (40) to its active position.
[3" id="US-20010004940-A1-CLM-00003] 3. Power nut runner according to
claim 1 or
2 , wherein the activation element (40) comprises a cylindrical sleeve (41) for co-operation with the sensor (46).
[4" id="US-20010004940-A1-CLM-00004] 4. Power nut runner according to
claim 1 or
2 , wherein said activation element (40) is cylindrical in shape, and said first clutch half (27, 30, 39) has a tubular contact portion (39) for abutting engagement with the activation element (40).
[5" id="US-20010004940-A1-CLM-00005] 5. Power nut runner according to anyone of claims 1-4, wherein the sensor (46) comprises a Hall-element type switch which co-operates in a contactless manner with the activation element (40).
[6" id="US-20010004940-A1-CLM-00006] 6. Power nut runner according to anyone of claims 1-5, wherein the rotation motor (10) is an electric motor, and an electric power control unit is connected to the motor (10) as well as to the sensor (46) and arranged to interrupt power supply to the motor (10) when receiving a signal from the sensor (46) at release of the clutch (26).
类似技术:
公开号 | 公开日 | 专利标题
EP1112819B1|2008-03-19|Power nut runner with torque responsive power shut-off capacity
US6062114A|2000-05-16|Power nutrunner
JP4041539B2|2008-01-30|Power nutrunner with torque release clutch and adjustment tool
US5199505A|1993-04-06|Rotary impact tool
EP0525911B1|1999-03-17|Transmission for electrically driven tool
EP0226426B1|1990-05-16|Two speed gearbox
EP2025473B1|2013-10-16|Impact wrench
US5054588A|1991-10-08|Torque sensing automatic shut-off and reset clutch for screwdrivers, nutsetters and the like
US8261849B2|2012-09-11|Jumbo hammer clutch impact wrench
US4880064A|1989-11-14|Torque sensing, automatic shut-off and reset clutch for screwdrivers, nutsetters and the like
US20080210736A1|2008-09-04|Hand-held drive-in tool
US4842078A|1989-06-27|Screw joint tightening power tool
US4919022A|1990-04-24|Ratchet wrench
US4429775A|1984-02-07|Clutch type torque control device for air driver
USRE33711E|1991-10-08|Ratchet wrench
US3428137A|1969-02-18|Impact wrench
JP2001505291A|2001-04-17|Electromechanical wheel brake device
SE505895C2|1997-10-20|Power screw driver
US3276524A|1966-10-04|Drive adapter for torque responsive control
EP0665385B1|1999-03-10|A torque responsive release clutch mechanism
WO1999016585A1|1999-04-08|Power nutrunner with shut-off
EP1245340A2|2002-10-02|Portable power tool for mounting via a press fit a machine part onto a shaft
EP1468796B1|2006-06-21|Chain saw with a clutch braking mechanism
US2586314A|1952-02-19|Roller device impact clutch
US7077255B2|2006-07-18|Pneumatic power nut runner with automatic shut-off
同族专利:
公开号 | 公开日
JP4897998B2|2012-03-14|
EP1112819B1|2008-03-19|
EP1112819A3|2003-03-19|
DE60038357D1|2008-04-30|
SE9904793D0|1999-12-28|
SE520916C2|2003-09-09|
SE9904793L|2001-06-29|
JP2001232577A|2001-08-28|
DE60038357T2|2009-07-09|
EP1112819A2|2001-07-04|
US6662882B2|2003-12-16|
引用文献:
公开号 | 申请日 | 公开日 | 申请人 | 专利标题
US20050247459A1|2004-05-04|2005-11-10|Mike Voigt|Method for operating a disengagable screwdriver, and a disengagable screwdriver|US3608686A|1969-12-18|1971-09-28|Thomas B Martin Sr|Automatic release clutch|
US4019589A|1975-12-02|1977-04-26|Chicago Pneumatic Tool Company|Pulse motor nut runner|
GB2002665B|1977-07-07|1982-03-03|Totsu K|Electrically driven fastening appliance|
CH648507A5|1982-09-22|1985-03-29|Cerac Inst Sa|ELECTRIC HITCHING MACHINE.|
DE3323251C2|1983-06-28|1990-09-06|Gewerkschaft Eisenhuette Westfalia Gmbh, 4670 Luenen, De||
US4721169A|1986-05-14|1988-01-26|Matsushita Electric Industrial Co., Ltd.|Electric driver with torque-adjustable clutch mechanism|
US4712456A|1986-07-02|1987-12-15|Top Driver Enterprise Co., Ltd.|Electric torsion-controlled screwdriver with an improved automatic turn-off device|
SE461510B|1986-11-27|1990-02-26|Atlas Copco Ab|ACTIVATION ARRANGEMENTS FOR ELECTRIC SCREW CARRIER|
DE4019895C2|1990-06-22|1999-04-08|Ceka Elektrowerkzeuge Ag & Co|Method and device for controlling the operation of handheld electrical devices|
SE466896B|1991-01-10|1992-04-27|Atlas Copco Tools Ab|POWER TOOL|
DE4204947A1|1992-02-19|1993-08-26|Scintilla Ag|POWERED HAND MACHINE|
US5346023A|1993-02-11|1994-09-13|Hitachi Koki Company Limited|Slipping torque changing apparatus for impact tool|
DE4344849A1|1993-12-29|1995-07-06|Fein C & E|Machine tool|
US5553675A|1994-06-10|1996-09-10|Minnesota Mining And Manufacturing Company|Orthopedic surgical device|
DE19527192A1|1995-07-26|1997-01-30|Hilti Ag|Screwdriver|
US5738177A|1995-07-28|1998-04-14|Black & Decker Inc.|Production assembly tool|
SE507908C2|1996-09-16|1998-07-27|Atlas Copco Tools Ab|Power nut puller with shutdown|
EP1024927A1|1997-09-26|2000-08-09|Atlas Copco Tools Ab|Power nutrunner with shut-off|
JP3744207B2|1998-06-30|2006-02-08|松下電工株式会社|Electric tightening tool with torque clutch|SE522094C2|2002-02-22|2004-01-13|Atlas Copco Tools Ab|Pneumatic nut wrench with torque coupling and a torque-sensitive coupling as well as a radial locking element for the inlet valve|
US6845279B1|2004-02-06|2005-01-18|Integrated Technologies, Inc.|Error proofing system for portable tools|
GB2414283A|2004-05-06|2005-11-23|Dyson Ltd|A slip responsive clutch in a vacuum cleaner|
US7836968B2|2006-03-24|2010-11-23|The Stanley Works|Power tool with improved start actuator|
JP5201842B2|2007-01-29|2013-06-05|勝行 戸津|Screwdriver torque detection device for electric screwdriver|
SE532395C2|2008-05-08|2010-01-12|Atlas Copco Tools Ab|Power tool for tightening screw joints and decoupling|
US8851201B2|2008-08-06|2014-10-07|Milwaukee Electric Tool Corporation|Precision torque tool|
SE0802248L|2008-10-22|2010-03-02|Atlas Copco Tools Ab|Nut wrench with a motion indicator for a variable torque dependent element in the power transmission|
DE102009047698A1|2009-12-09|2011-06-16|Robert Bosch Gmbh|Hand tool machine comprises driving motor which is coupled with tool holding device over drive that comprises coupling device, where driving motor comprises switch|
US9289886B2|2010-11-04|2016-03-22|Milwaukee Electric Tool Corporation|Impact tool with adjustable clutch|
JP5910858B2|2012-01-16|2016-04-27|日立工機株式会社|Chain saw|
DE102013100986A1|2013-01-31|2014-07-31|C. & E. Fein Gmbh|Screwdriver has sensor that is arranged for monitoring tool spindle in response to acceleration of tool spindle in axial direction, and controller for controlling drive based on sensor signal|
JP2014172164A|2013-03-13|2014-09-22|Panasonic Corp|Electric power tool|
US10583894B2|2017-09-14|2020-03-10|Honda Motor Co., Ltd.|Motor power transmission device|
DE102018100664A1|2018-01-12|2019-07-18|STAHLWILLE Eduard Wille GmbH & Co. KG|torque tool|
法律状态:
2000-12-28| AS| Assignment|Owner name: ATLAS COPCO TOOLS AB, SWEDEN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HANSSON, GUNNAR CHRISTER;REEL/FRAME:011423/0755 Effective date: 20001220 |
2003-11-25| STCF| Information on status: patent grant|Free format text: PATENTED CASE |
2007-05-25| FPAY| Fee payment|Year of fee payment: 4 |
2011-05-18| FPAY| Fee payment|Year of fee payment: 8 |
2015-06-16| FPAY| Fee payment|Year of fee payment: 12 |
优先权:
申请号 | 申请日 | 专利标题
SE9904793||1999-12-28||
SE9904793-8||1999-12-28||
SE9904793A|SE520916C2|1999-12-28|1999-12-28|Nut wrench with torque clutch with trigger sensor for power shut-off|
[返回顶部]