Having Torque Sensor Patents (Class 173/181)
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Patent number: 7882899Abstract: A power tool comprising a housing, a motor, an output shaft, a gear transmission mechanism and a control system. The gear transmission mechanism is connected between the motor and the output shaft to transmit the rotary power of the motor to the output shaft. The gear transmission mechanism has a high speed position and a low speed position. The control system is coupled to the gear transmission mechanism for detecting an operating characteristic of the power tool to actuate a ring gear to automatically move from the high speed position to the low speed position and to reduce the rotational speed of the ring gear when the operating characteristic exceeding a predetermined value.Type: GrantFiled: August 26, 2008Date of Patent: February 8, 2011Assignee: Positec Power Tools (Suzhou) Co., LtdInventors: Gianni Borinato, Kelvin Wong, Shisong Zhang, Paolo Andriolo, Warren Brown, Hongfeng Zhong, Fangshi Liu, Chengzhong Chen
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Publication number: 20110000688Abstract: Tightening torque is appropriately managed by a simple means. An electric rotating tool (40) has a brushless DC motor (2), an inverter circuit part (3), and a control circuit part (4). The control circuit part (4) has a current detecting circuit (18), which detects a motor current I, a rotation number detecting circuit (17), which detects the number of rotations of the motor (N), and a computing part (19), which calculates first tightening torque (T1) based on the detection information of the motor current (I) and calculates second tightening torque (T2) based on the number of rotations of the motor (N). The computing part (19) estimates tightening torque Tave based on the estimate value of the first tightening torque (T1) or the second tightening torque (T2). The computing part (19) stops driving the motor (2) when the estimated tightening torque Tave exceeds a set value Tset.Type: ApplicationFiled: February 16, 2009Publication date: January 6, 2011Inventor: Kazutaka Iwata
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Patent number: 7795829Abstract: In an electric power tool and a method for operating an electric power tool, a torque limitation of an electric motor reacts when a load moment exceeds a predetermined threshold and in which an output request is carried out by means of a switch. A supply of current to the motor is interrupted when a criterion for the reaction of the torque limitation is detected based on a speed detection of the motor.Type: GrantFiled: April 3, 2007Date of Patent: September 14, 2010Assignee: Robert Bosch GmbHInventors: Hartmut Seiler, Dirk Lamprecht
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Patent number: 7770658Abstract: An object is to improve accuracy of tightening torque and to shorten time necessary for fastening a screw in an impact type screw fastening device that uses an electric motor as a rotation driving source. A control method for the impact type screw fastening device that uses an electric motor as a rotation driving source includes the steps of driving the motor to rotate by supplying current to the motor intermittently so that torque exerted on a load by rotation of the motor becomes like pulses on the time axis, and controlling the current of every time of each pulse so that an increment of every time of each pulse of the torque after the torque reaches a target approach torque TQN that is a first set value becomes smaller than that before it reaches the target approach torque TQN.Type: GrantFiled: May 10, 2006Date of Patent: August 10, 2010Assignees: Estic Corporation, Honda Motor Co., Ltd.Inventors: Takaya Ito, Yoshitsugu Shibata, Hitoshi Takamura
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Publication number: 20100147545Abstract: The invention is based on a device for handheld power tool for detecting a torque, having at least one sensor unit. It is proposed that the sensor unit is intended for detecting a deformation parameter. The sensor unit has at least one sensor element that is embodied as a strain gauge. A gearbox is provided which has a bearing location for receiving a deformation element of the sensor unit. An electronic unit evaluates detected data from the at least one sensor unit.Type: ApplicationFiled: December 11, 2009Publication date: June 17, 2010Inventors: Daniel HIRT, Ursula Faber
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Patent number: 7730964Abstract: The invention relates to a power tool having a change-speed gear device comprising a plurality of gears (1, 2) for adjusting on demand power stages of a drive, wherein an overload protection can be coupled to the gears (1, 2). According to the invention, the device comprises at least one gear (3) in which the overload protection function can be forcibly deactivated. The invention also relates to an overload protection.Type: GrantFiled: July 3, 2006Date of Patent: June 8, 2010Assignee: Robert Bosch GmbHInventors: Robert Simm, Cornelis Van Der Schans, Markus Weber
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Patent number: 7726412Abstract: A tightening tool for tightening a fastener is disclosed which comprises a motor and a main shaft that engages with the fastener. A clutch is disposed between the motor and the main shaft so that the clutch rotates the main shaft by transmitting torque from the motor to the main shaft when a load acting on the main shaft is less than a predetermined value. The clutch shuts off torque transmission from the motor to the main shaft when the load acting on the main shaft reaches or exceeds the predetermined value. When in use, the current flowing to the motor and rotation angle of the main shaft of the motor are detected. The detected current and rotation angle are used to determine whether the tightening torque of the fastener is normal.Type: GrantFiled: June 2, 2009Date of Patent: June 1, 2010Assignee: Makita CorporationInventor: Yutaka Matsunaga
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Publication number: 20100116101Abstract: Device (10, 20, 30) and method for tightening a bolt (2) or a nut (12) threaded on its end, which end extends through at least a first body (3) and screws into a hole (5) in a second body (4) or extends through the second body into another nut (13). The device has gripping means (7, 17) co-acting with the bolt-head or the nuts. Means (8) process a signal generated by sensor means (18) subject to the axial force exerted on the surface of the first body by the bolt-head or the first nut, or on the surface of the second body by the second nut, and control the device such that the bolt-head or a nut is tightened subject to the axial force exerted on the surface- of one of the bodies, which sensor means are in an annular body (16) around the threaded hole between the bolt-head or first nut and the first body or between the second nut and second body.Type: ApplicationFiled: December 13, 2007Publication date: May 13, 2010Applicant: Industrial Bolting Technology And Supply Group B.V .Inventors: Nico Anthonie Dral, Matheus Theodoor Hendrik Marie Van Kortenhof
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Patent number: 7712546Abstract: It is an object of the invention to provide an effective technique for avoiding the influence of reaction during tightening operation in the rotary fastening tool.Type: GrantFiled: March 2, 2007Date of Patent: May 11, 2010Assignee: Makita CorporationInventor: Manabu Tokunaga
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Publication number: 20100059240Abstract: Disclosed is a method for screwing in and tightening a screw connection (1) to a predetermined tightened level (2), especially a predetermined torque level (2) or a predetermined pretension level, with the aid of a hand-held screwing tool (3) comprising a regulated drive unit (4) and/or control functionality, particularly an electric nut runner (3). A tightening phase (B-C-D), during which the screw head rests against the supporting surface (6) of the screw connection (1), starts following a screwing phase (A). In order to improve said method, the speed (N) of the screwing tool (3) is increased to an output speed (7) for the tightening phase (B-C-D) within an acceleration time (8) in the tightening phase (B-C-D) and is lowered within a delay time (9) prior to or until reaching the predetermined tightened level (2).Type: ApplicationFiled: March 24, 2007Publication date: March 11, 2010Inventor: Heike Schmidt
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Publication number: 20090277658Abstract: The present invention has disclosed a variable speed tool and a variable speed control method. The tool includes a switch; a gearbox housing; a motor; an outputting shaft; a multistage transmitting gear train and a gearshift ring which are mated with the motor and the outputting shaft, the gearshift ring having inner teeth; a gearshift fork mated with the gearshift ring; a tension spring arranged between the gearbox housing and the gearshift fork; and a torque sensing ring provided with a sliding groove in which the gearshift fork is movably disposed. When the load of the outputting shaft has reached to a predetermined value, the torque sensing ring makes the gearshift fork move axially in the sliding groove under the action of the tension spring, thus bringing the gearshift ring to move axially. The variable speed tool of the present invention may automatically adjust the rotating speed and the torque of the outputting shaft according to a variation of the load torque.Type: ApplicationFiled: June 15, 2007Publication date: November 12, 2009Applicant: POSITEC POWER TOOLS (SUZHOU) CO., LTD.Inventor: Chengzhong Chen
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Patent number: 7600577Abstract: A device for sensing a direction of rotation of a hand tool having an electric motor, has a rotatably supported brush plate provided in the electric motor and located in different positions depending on a direction of rotation of the electric motor; and at least one sensor which senses the different positions of said brush plate to determine a direction of rotation, wherein said sensor is configured as a contactless sensor.Type: GrantFiled: December 26, 2006Date of Patent: October 13, 2009Assignee: Robert Bosch GmbHInventors: Robert Simm, Markus Weber, Bernhard Roth
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Patent number: 7588098Abstract: An object of the present invention is to provide an electric screwdriver device having a function for determining that a correct tightening operation has been carried out when the tightening operation has taken a time longer than a reference time predetermined for the tightening operation, characterized in comprising a novel feature for determining the reference time.Type: GrantFiled: April 16, 2008Date of Patent: September 15, 2009Assignee: Nitto Kohki Co., Ltd.Inventors: Hiroyuki Nakazawa, Hideki Fujita
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Publication number: 20090194307Abstract: A rotation driver and method for transmitting a limit torque to a fastener by having cam members which rotate together for torquing and then reverse the rotation to return to their starting position for repeating the torquing. The same two surfaces respectively on the two cam members always contact only each other for the torquing. There is lost motion between the cam members at the end of the limit torquing, and there can be further application of torque beyond the limit. A calibration adjuster urges the cam members together, and a lock arrangement secures the adjuster in its calibrated position. Also, there can be drive rotation in the direction reverse from the limit torque application.Type: ApplicationFiled: December 28, 2005Publication date: August 6, 2009Inventor: James A. Rinner
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Patent number: 7565935Abstract: The tap driver is configured to be hand-held. It has a tap-holding chuck and a motor to drive the chuck. An external switch rocks forward to rotate the motor in the tapping direction and backward to withdraw the tap. A control circuit causes forward motion of the tap for a predetermined time for the tap to make about one forward turn for tapping. At the end of that time, the motor reverses and rotates the tap outward a fractional turn to break the chips made during tapping. The timer then turns the circuit to drive the motor in the forward direction for another tapping. This action repeats until tapping is complete and the switch is rocked back to reverse the motor to withdraw the tap.Type: GrantFiled: May 26, 2006Date of Patent: July 28, 2009Inventor: Robert E. Phillips
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Patent number: 7556103Abstract: A fastening tool with a clutch for shutting off transmission of torque, capable of self-diagnosing fastening torque of a screw or the like at low cost without using expensive elements such as a torque sensor, etc. A fastening tool (10) has a motor (13), a main shaft (20) engaging with a screw or the like, and a clutch (14) interposed between the motor (13) and the main shaft (20). The clutch (14) transmits torque from the motor (13) to the main shaft (20) when a load acting on the main shaft (20) is less than a predetermined value, and shuts off torque transmission from the motor (13) to the main shaft (20) when a load acting on the main shaft (20) is equal to or greater than the predetermined value. The fastening tool (10) further has a control unit (60) for controlling the motor (13).Type: GrantFiled: March 10, 2005Date of Patent: July 7, 2009Assignee: Makita CorporationInventor: Yutaka Matsunaga
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Publication number: 20090139738Abstract: The invention proposes a method for controlling the tightening angle of screwed joints when tightening is effected using a hand-held screwing tool, wherein the torque is monitored until a predefined threshold value is reached, the angle of rotation is measured from the point the threshold value has been reached, the relative rotation of the screwing tool relative to the screwed joint is measured from the point the threshold value has been reached, and the screwing tool is switched off when a predetermined angle of rotation is reached, taking into account the relative angle of rotation of the screwing tool relative to the screwed joint as a corrective value.Type: ApplicationFiled: December 4, 2008Publication date: June 4, 2009Inventor: Peter Lippek
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Publication number: 20090014192Abstract: An object is to improve accuracy of tightening torque and to shorten time necessary for fastening a screw in an impact type screw fastening device that uses an electric motor as a rotation driving source. A control method for the impact type screw fastening device that uses an electric motor as a rotation driving source includes the steps of driving the motor to rotate by supplying current to the motor intermittently so that torque exerted on a load by rotation of the motor becomes like pulses on the time axis, and controlling the current of every time of each pulse so that an increment of every time of each pulse of the torque after the torque reaches a target approach torque TQN that is a first set value becomes smaller than that before it reaches the target approach torque TQN.Type: ApplicationFiled: May 10, 2006Publication date: January 15, 2009Applicants: ESTIC CORPORATION, HONDA MOTOR CO., LTD.Inventors: Takaya Ito, Yoshitsugu Shibata, Hitoshi Takamura
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Patent number: 7467669Abstract: A method and a power tool system are provided for performing screw joint tightening using a pneumatic torque impulse power tool that is controlled by a control unit. A torque magnitude and a torque growth are calculated based on signals delivered by an angle sensor, and pressurized air is supplied to the power tool via a flow regulating valve which is successively adjustable between zero and full power flow. The flow regulating valve is controlled by the control unit to deliver a reduced power air flow to the power tool before and during a first delivered impulse, and then to deliver full power flow until a certain torque magnitude or a percentage of a target torque level is reached, whereafter the air supply flow is again reduced until the target torque level is reached, and when the target torque level is reached the air flow is shut off.Type: GrantFiled: December 27, 2004Date of Patent: December 23, 2008Assignee: Atlas Copco Tools ABInventors: John Robert Christian Friberg, Knut Christian Schoeps, Torbjörn Rafael Sjöblom, Erland Karlberg
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Patent number: 7464612Abstract: A make-up assembly and process provides a true power-tight connection between a first and second tubular segment. Each of the segments has an externally threaded male member at one end and an internally threaded female member at the other end. The male member of the first segment is inserted into the female member of the second segment. A primary torque component is applied to the first segment to engage the external threads of the first segment with the internal threads of the second segment and to advance the male member of the first segment into the female member of the second segment. The value of the primary torque component is monitored. An impulse energy component is then superimposed on the primary torque component when a predetermined onset threshold has been reached. Application of one or both of the primary and impulse energy components is discontinued when a predetermined maximum threshold has been reached.Type: GrantFiled: June 6, 2006Date of Patent: December 16, 2008Inventors: Eugene J. Manella, Gregory K. Otten
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Patent number: 7428934Abstract: In an impact fastening tool, erroneous detection of a strike by a hammer is prevented. The impact fastening tool includes a strike mechanism that transmits a driving force of a motor to an output shaft with an impact force generated by striking an anvil by the hammer, a fastening torque calculator that calculates a fastening torque equivalent to an actual fastening torque generated by the impact forces, a strike detector that detects occurrences of strikes by the hammer, a motor controller that stops the driving of the motor at a time when the fastening torque reaches a predetermined reference value, a current detector that detects current information in an interval of strikes, and a strike judger that judges whether the detection of a strike is real or unreal by using current information. The fastening torque calculator calculates the fastening torque by ignoring the strike judged real by the strike judger.Type: GrantFiled: February 22, 2006Date of Patent: September 30, 2008Assignee: Matsushita Electric Works, Ltd.Inventor: Tadashi Arimura
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Patent number: 7419013Abstract: A rotary impact tool can be used in a work especially precision or finishing of fastening is important. The rotary impact tool comprises a rotary driving mechanism including a driving source for rotating a driving shaft, a hammer fixed on the driving shaft, an output shaft to which a driving force is applied by impact blow of the hammer, a torque setting unit used for setting a fastening torque, a processor for calculating fastening torque from impact blow of the hammer, a rotation speed setting unit used for setting rotation speed of the driving shaft, and a controller for rotating the driving shaft of the rotary driving mechanism in a rotation speed set in the rotation speed setting unit and for stopping rotation of the driving shaft of the rotary driving mechanism when the fastening torque calculated in the processor becomes equal to or larger than a reference value of fastening torque previously set in the torque setting unit.Type: GrantFiled: May 11, 2005Date of Patent: September 2, 2008Assignee: Matsushita Electric Works, Ltd.Inventors: Yoshinori Sainomoto, Tatsuhiko Matsumoto, Tadashi Arimura, Toshiharu Ohashi, Hidenori Shimizu, Fumiaki Sawano
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Patent number: 7395874Abstract: A slaving and blocking device for transmitting a torque from a driving part to a driven part and for stopping the driven part at a torque engaging the driven part has a slaving unit fixable on the driving part fixed against relative rotation and having slaving claws that are offset from one another in a circumferential direction, a roller star wheel located in the slaving unit and connectable to the driven part fixed against relative rotation, clamping bodies located in freewheeling fashion between the slaving claws and points of a star of the roller star wheel, a stationary clamping ring located concentrically to the slaving means and the roller star wheel and having an inner annular face forming a counterpart clamping face for the clamping bodies, and radially displaceable centrifugal force elements located in the roller star wheel such that above a predetermined rpm the force elements clamp the roller star wheel firmly to the slaving means.Type: GrantFiled: November 14, 2005Date of Patent: July 8, 2008Assignee: Robert Bosch GmbHInventor: Olivier Zeiter
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Patent number: 7350286Abstract: Threaded member assembling can be performed using a rotational/axial-movement-transmitting unit including an upper frame; a motor held by the upper frame; a female threaded member secured to the upper frame; a male threaded member assembled in the female threaded member, the male threaded member having a rotational/axial-movement-transmitting end at one end, and having a driven rotary end at the other end; and a joint member connecting an output terminal of the motor to the driven rotary end for transmitting rotation torque from the output terminal to the driven rotary end and for allowing axial movement of the male threaded member relative to the motor.Type: GrantFiled: September 8, 2004Date of Patent: April 1, 2008Assignee: Aisin AW Co., Ltd.Inventors: Yoshiaki Asano, Shingo Hashimoto
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Patent number: 7336048Abstract: In a method for operating a power tool with an energy accumulator, in particular a rechargeable energy accumulator, which supplies power to an electric drive motor, a clock frequency is generated by an electronic unit, with which a gate of a MOSFET—which supplies operating voltage to the drive motor—is switched on with each cycle, and a switching-off of the MOSFET is carried out within one cycle using different signals, as a function of operating parameters.Type: GrantFiled: May 2, 2006Date of Patent: February 26, 2008Assignee: Robert Bosch GmbHInventor: Guenter Lohr
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Publication number: 20080000333Abstract: The present invention aims to provide a screw fastening machine for reliably switching and changing a driving force transmitting path with the seating on a work as a reference. According to the screw fastening machine in which a first pulley is connected to a first driving means for applying high speed low torque drive to a drive shaft, a second pulley is fixed in an integrally rotatable manner to a transmission shaft for connecting the drive shaft, and an endless belt is interposed between the pulleys to obtain a configuration for high speed low torque drive, a second driving means for low speed high torque drive is arranged on an extension of the transmission shaft, and the second driving means performs the drive until a final fastening torque is reached when a screw component is seated on the work and the stall state is achieved, the final fastening torque is always reliably obtained and the work time is reduced without waste.Type: ApplicationFiled: July 2, 2007Publication date: January 3, 2008Inventor: Tasuku Seno
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Patent number: 7146715Abstract: Apparatus for installing a rivet nut or the like having an intentionally threaded shaft wherein the apparatus includes a hydraulically geared power tool having an inner hydraulic fluid containing a chamber and a screw adapted to engage the threaded shaft of the nut wherein the power tool rotates the screw when actuated. A fluid outlet is coupled to the chamber and is coupled to a gauge controlled power supply, the power supply being fluidly coupled to the power tool whereby the power supply includes torque predetermining device for determining when a predetermined torque is placed on the screw, this stopping rotation thereof and resuming rotation in an opposite direction to withdraw the screw from the nut.Type: GrantFiled: August 3, 2004Date of Patent: December 12, 2006Assignee: AVK Industrial ProductsInventor: Ramon Cruz Villanueva
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Patent number: 7090031Abstract: An intelligent tightening spindle comprises a drive output; a housing adapted to detachably mount to a moving platform of a multi-tool processing station, with the housing substantially enclosing: at least one electric drive motor having an associated servo amplifier; a gear unit operatively connecting the drive motor to the drive output; a spindle measurement transducer operative to monitor at least one of the drive motor, the gear unit, and the drive output; and a measurement data processing unit in communication with the spindle measurement transducer. An output signal port may have signals applied thereto representing measurement data that has been processed by the measurement data processing unit. The measurement transducer and/or the data processing unit may be removably coupled to the spindle via one or more electrical connectors. One or more of the tightening spindles may be used to form a multi-tool processing station.Type: GrantFiled: July 27, 2004Date of Patent: August 15, 2006Assignee: Cooper Power Tools GmbH & Co.Inventor: Ulrich Kaminski
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Patent number: 7086483Abstract: An electric tool having the capability of achieving a high working efficiency is provided. This tool comprises an output shaft rotated by reversible motor, a rotational-direction switch for switching a rotational direction of the output shaft in either forward or reverse direction, first memory for storing a plurality of operation modes of the output shaft with respect to one of the forward and reverse directions, operation-mode switch for selecting one from the operation modes, second memory for temporarily storing an operation mode selected by the operation-mode switch in a use of the electric tool at the one of the forward and reverse directions; and a controller for automatically setting the electric tool in the operation mode stored in the second memory in the next use of the electric tool at the one of the forward and reverse directions.Type: GrantFiled: August 25, 2004Date of Patent: August 8, 2006Assignee: Matsushita Electric Works, Ltd.Inventors: Tadashi Arimura, Hiroshi Miyazaki, Masatoshi Ito, Yukihiko Okamura, Kenji Sakamoto
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Patent number: 7063171Abstract: An electric motor-driven rotary tool with an elevated temperature detection function, provided by a temperature sensor, connected to a power shut off device, for shutting off power to the tool, in order to prevent injury, such as low temperature burn, from occurring to an operator of the tool, due to heating of the electric motor, encased in a housing having a holding part for the motor-driven rotary tool, causing an increase of the temperature of the housing, especially the holding part of the tool thereon, to a temperature capable of causing such burn injury to the operator of the tool.Type: GrantFiled: January 22, 2002Date of Patent: June 20, 2006Inventor: Katsuyuki Totsu
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Patent number: 7053567Abstract: It is an object of the invention to provide a technique to effectively prevent a power tool from being adversely affected when a battery is removed from the power tool. According to the present invention, a power tool is provided that includes a tool bit, a motor that drives the tool bit, a body that houses the motor, a battery detachably coupled to the body so as to supply driving current to operate the motor, a control device that controls the operation of the motor and a power circuit that leads the driving current from the battery to the motor. Within the power tool, the control device stops the motor prior to an interruption of the power circuit when the battery is disengaged from the body in order to prevent a large driving current from being passed through the power circuit. As a result, arc can be effectively prevented from being generated between the battery and the body of the power tool.Type: GrantFiled: March 12, 2003Date of Patent: May 30, 2006Assignee: Makita CorporationInventor: Hirokatsu Yamamoto
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Patent number: 7036703Abstract: The present invention relates to a hand-held working tool, such as a setting device used for driving fastening elements such as nails, bolts, pins and the like into a surface, or an at least partially percussive hand-held tool having a housing part (11) and a working mechanism such as a setting or striking mechanism arranged inside the housing of the device and having at least one sensing device (17) for sensing acceleration forces occurring during a setting or striking pulse as well as a handle. For improving this type of hand-held working tool (10) an interface (30) for data communication and data output is arranged on the hand-held working tool.Type: GrantFiled: January 27, 2004Date of Patent: May 2, 2006Assignee: Hilti AktiengesellschaftInventors: Mario Grazioli, Joachim Keck
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Patent number: 6978846Abstract: In a power impact tool for fastening a screw or a bolt, malfunction that driving of a motor is stopped before the screw or the bolt is fastened completely can be prevented. A fastening judger judged that the fastening operation is completed at least when a torque variation ratio becomes substantially zero and a reference index becomes equal to or larger than a threshold value of trouble judgment. The reference index is a number of impact of a hammer in a term in which the torque variation ratios take positive values, and the threshold value of trouble judgment is calculated with using a maximum value of the torque variation ratio in the term. Since the number of the impact of the hammer due to trouble in fastening operation is smaller than that due to the screw or the bolt is fastened completely, it is possible to distinguish the increase of the torque in the former case from the increase of the torque in the latter case.Type: GrantFiled: August 25, 2004Date of Patent: December 27, 2005Assignee: Matsushita Electric Works, Ltd.Inventors: Kozo Kawai, Yoshinori Sainomoto
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Patent number: 6968908Abstract: Power tool (11) may include a motor and oil pulse unit (22) that generates an elevated torque. Oil pulse unit (22) may be coupled to the motor and have output shaft (18). When load acting on output shaft (18) is less than a predetermined value, rotating torque generated by the motor is directly transmitted to output shaft (18). When the load acting on output shaft (22) exceeds the predetermined value, an elevated torque is generated by oil pulse unit (22) and applied to output shaft (18). Output shaft (18) may be connected to load shaft (12). A socket may be attached to the distal end of load shaft (12). Power tool (11) may further include detecting device (20) for detecting change in rotational angle of output shaft (18) and the direction of rotation thereof, and a control device. The detecting device (20) may output signals corresponding to a state of output shaft (18) to the control device. The control device may store the state of output shaft (18) at predetermined interval.Type: GrantFiled: February 4, 2004Date of Patent: November 29, 2005Assignee: Makita CorporationInventors: Manabu Tokunaga, Goshi Ishikawa
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Patent number: 6945337Abstract: In a power impact tool for fastening a fastening member, a torque for fastening the fastening member can be estimated without using a high-resolution sensor and a high-speed processor.Type: GrantFiled: October 13, 2004Date of Patent: September 20, 2005Assignee: Matsushita Electric Works, Ltd.Inventors: Kozo Kawai, Yoshinori Sainomoto, Tatsuhiko Matsumoto, Tadashi Arimura, Toshiharu Ohashi, Hiroshi Miyazaki, Hidenori Shimizu, Fumiaki Sawano
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Patent number: 6933689Abstract: It is an object of the invention to provide a technique to effectively prevent a power tool from being adversely affected when a battery is removed from the power tool. According to the present invention, a power tool is provided that includes a tool bit, a motor that drives the tool bit, a body that houses the motor, a battery detachably coupled to the body so as to supply driving current to operate the motor, and a battery removal preventing device. Within the power tool, the battery removal preventing device prevents the battery from being removed from the body during operation of the motor and allows the battery to be removed from the body only when the motor is stopped. As a result, arc can be effectively prevented from being generated between the battery and the body of the power tool.Type: GrantFiled: April 25, 2003Date of Patent: August 23, 2005Assignee: Makita CorporationInventor: Hirokatsu Yamamoto
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Patent number: 6910540Abstract: A torque control system for electrically driven rotating tools capable of always properly and efficiently effecting constant-torque tightening of screws or the like and capable of easily achieving the miniaturization of the whole device and the improvement in torque control accuracy, the torque control system comprising a clutch mechanism that, when a load torque of predetermined value or above acts on a driven shaft joined to the output shaft of an electric motor, operates to cut off the engagement between the output shaft and the driven shaft, a torque setting mechanism that adjusts the engagement point for the clutch mechanism, and a torque detecting mechanism (42) for detecting the clutch operation of the clutch mechanism to effect drive stop control of the electric motor, wherein the torque detecting mechanism (42) is set so that it effects drive stop control of the electric motor simultaneously with the detecting operation thereof in a state in which the clutch operation has been completed as the cam enType: GrantFiled: April 18, 2002Date of Patent: June 28, 2005Inventor: Katsuyuki Totsu
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Patent number: 6892826Abstract: An impact tool having a control system for turning off a motor at a preselected torque level.Type: GrantFiled: January 7, 2003Date of Patent: May 17, 2005Assignee: Chicago Pneumatic Tool CompanyInventor: David A. Giardino
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Patent number: 6871153Abstract: This dynamic calibration qualifier relates to a tool monitor and assembly qualifier that verifies that the correct number of fasteners have been properly installed into an assembly. The device monitors an analog signature created by the tool and has the ability to dynamically calibrate itself while the tool is running. In the preferred embodiment, the stored variable is a clutch offset identified during a calibration phase. In a pulse tool, the programmed microprocessor is configured to identify and store the peak pressure of the first three pulses which are averaged together. The clutch offset is added to the average pulse value from which the clutch threshold is generated.Type: GrantFiled: November 20, 2003Date of Patent: March 22, 2005Assignee: C.E. Electronics, Inc.Inventor: Richard G. Lysaght
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Patent number: 6848516Abstract: An impact tool having a control system for turning off a motor at a preselected torque level.Type: GrantFiled: January 7, 2003Date of Patent: February 1, 2005Assignee: Chicago Pneumatic Tool CompanyInventor: David A. Giardino
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Patent number: 6782594Abstract: The present invention is directed towards a method and an apparatus for accurately estimating the tension or clamp force in a bolted joint. An installed fastener is rotated and the torque necessary to rotate the fastener and the angle through which the fastener is rotated are measured. The angle and torque values are plotted against one another such that the angle values are plotted on an angle axis and the torque values are plotted on a torque axis. A tangent is extended from the plot towards the angle axis. The point at which the tangent crosses the angle axis is defined as zero degrees and is called the “elastic origin”. The known angle through which the fastener rotates is used to scale the angle axis. The angle from the elastic origin to the point at which the tangent was drawn is defined as the M-alpha angle and is directly proportional to the clamp force created by the bolted joint or tension in the fastener.Type: GrantFiled: April 3, 2001Date of Patent: August 31, 2004Inventor: Ralph S. Shoberg
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Patent number: 6765357Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.Type: GrantFiled: August 5, 2002Date of Patent: July 20, 2004Assignee: Magna-Lastic Devices, Inc.Inventors: David W. Cripe, Christopher Jones
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Patent number: 6761229Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.Type: GrantFiled: August 5, 2002Date of Patent: July 13, 2004Assignee: Magna-Lastic Devices, Inc.Inventors: David W. Cripe, Christopher Jones
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Patent number: 6680595Abstract: It is an object of the present invention to overcome various drawbacks of a conventional oil pulse wrench by using an electric motor, to reduce a reaction force and to fasten a screw with high precision. To achieve the object, the invention provides a control method of a screw fastening apparatus using an electric motor as a rotation driving source, the method comprising the steps of; intermittently supplying current pulse DP to the motor, detecting an actual torque at predetermined time intervals, maintaining a current value when a detected torque value does not exceed a maximum value of past detected torques value and increasing the current value by a predetermined amount when the detected torque value exceeds the maximum value of the past detected torque value, and stopping the supply of the current pulse DP when the detected torque value reaches a target value TQJ.Type: GrantFiled: December 19, 2002Date of Patent: January 20, 2004Assignee: Estic CorporationInventor: Takaya Ito
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Patent number: 6655471Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.Type: GrantFiled: December 15, 2000Date of Patent: December 2, 2003Assignee: Magna-Lastic Device, Inc.Inventors: David W. Cripe, Christopher Jones
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Patent number: 6581696Abstract: An impact tool having a control system for turning off a motor at a preselected torque level.Type: GrantFiled: June 1, 2001Date of Patent: June 24, 2003Assignee: Chicago Pneumatic Tool CompanyInventor: David A. Giardino
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Patent number: 6559613Abstract: An open end power wrench includes an operating scheme that identifies when the item within the drive socket is an item that should be rotated by the drive socket. The method for controlling the tube nut wrench includes the steps of operating the motor to generate an output torque. The method then measures an angle of rotation through which the drive socket rotates. The angle of rotation is then compared with an angle defined by the clearance opening. The output torque is limited to a minimal torque level when the angle of rotation of the drive socket is less than the angle defined by the clearance opening. The method then increases the output torque to an operating torque level when the angle of rotation of the drive socket exceeds the angle defined by the clearance opening.Type: GrantFiled: October 25, 2001Date of Patent: May 6, 2003Assignee: AcraDyneInventors: David J. Elliott, Mark W. Lehnert
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Patent number: 6473962Abstract: Apparatus and method precisely preload bearings onto shafts. A swivel plate swivels up to 360° and locks a rotary shaft axially with a motor shaft. A shim and bearing adjacent the shim preload onto shaft shoulder by lock nut secured to the threaded shaft. The lock nut forces the bearing inner race to expand outwardly, preloading the bearing. A force sensor measures torque on the bearing outer race. Measured torque is monitored within a predetermined range to establish the precisely loaded bearing. The method slides a shim onto support shaft shoulder. A bearing is slid onto tapered surface, and lock nut tightened onto the threaded shaft. The lock nut expands the bearing inner race, reducing the distance between the inner and outer races and preloading the bearing. The outer race at a predetermined, constant speed has torque monitored to a predetermined range to provide a precisely preloaded bearing.Type: GrantFiled: October 10, 2000Date of Patent: November 5, 2002Assignee: Kimberly-Clark Worldwide, Inc.Inventor: Mark W. Beduhn
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Patent number: 6460629Abstract: The present application relates to a pneumatic tool for applying torque to fasteners and a system incorporating such a tool.Type: GrantFiled: November 14, 2001Date of Patent: October 8, 2002Assignee: The Stanley WorksInventors: Duane R. Bookshar, James F Steverding, Michael Juliano
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Patent number: 6378623Abstract: A torque control type impact wrench includes a first storage section for storing an ideal upper limit of the pulsed torque for screwing a male screw into a female screw, as a first storage value, a second storage section for storing a driving speed at which a driving section drives a torque producing section as a second storage value, and a control section for causing the driving section to drive the torque producing section at the second storage value and stopping the driving section when the pulsed torque exceeds the first storage value, wherein the control section causes the second storage section to store a value, which is larger than the second storage value, as a new second storage value when the pulsed torque does not reach the first storage value within a given time period after the driving section starts.Type: GrantFiled: January 25, 2001Date of Patent: April 30, 2002Assignee: Nitto Kohki Co., Ltd.Inventor: Masaki Kawarai