Patents Assigned to KOKI HOLDINGS CO., LTD.
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Publication number: 20200189064Abstract: Provided is an electric tool in which the risk of short-circuiting between conductive members of multiple installed switching elements has been reduced by providing partitioning plates between the switching elements. An electric tool, which has a motor, an inverter circuit with multiple switching elements for performing switching operations and controlling the driving of the motor, a control unit for controlling switching element on-off operations, and a circuit board on which the switching elements are loaded, is configured so that the circuit board is housed inside a container-shaped case (40) and the circuit board is secured with a partitioning member (50) that is interposed between the multiple switching elements and has partitioning plates (51, 52a, 52b) obtained from an insulating material.Type: ApplicationFiled: February 26, 2020Publication date: June 18, 2020Applicant: Koki Holdings Co., Ltd.Inventors: Yuuki TAKEDA, Hironori SAKAI
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Publication number: 20200180044Abstract: The electrical device comprises a common device main body having selectively and detachably attached thereto either a variable-voltage power supply device or a high-voltage power supply device. The device main body has: a protruding section that abuts a power supply-side main erroneous attachment prevention section provided in the variable-voltage power supply device and the high-voltage power supply device; a device-side main erroneous attachment prevention section that abuts the power supply-side main erroneous attachment prevention section provided in a low-voltage power supply device and prevents the low-voltage power supply device from abutting an attachment positioning section; and a device-side attachment pet' lifting section that can be combined in a power supply-side auxiliary erroneous attachment prevention section provided in the high-voltage power supply device.Type: ApplicationFiled: July 27, 2018Publication date: June 11, 2020Applicant: Koki Holdings Co., Ltd.Inventors: Yusuke FUNABIKI, Tomomasa NISHIKAWA, Takuya Teranishi, Masayuki Ogura
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Patent number: 10666168Abstract: Provided is an easy-to-use electric tool with which braking force can be changed according to work conditions. When an operation switch 5 is turned off, a control unit 50 detects a rotation rate R1 of an electric motor 6. The control unit 50 stands by for a prescribed period, detects a rotation rate R2 of the electric motor 6, and calculates the difference between the rotation rates R1, R2 (R=R1?R2). Since the rotation rate difference R corresponds to the rate of change in rotation rate with time during deceleration of the electric motor 6 and is smaller the larger the moment of inertia of the attached rotary tool, the control unit 50 can determine the moment of inertia of the rotary tool on the basis of the rotation rate difference R. The control unit 50 sets the braking force according to the moment of inertia and performs braking.Type: GrantFiled: October 30, 2015Date of Patent: May 26, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventor: Yuuki Takeda
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Patent number: 10661427Abstract: A power tool has a fan guide for straightening the flow of cooling air generated by a fan, wherein the branching passages through are provided for causing a portion of the cooling air drawn into the fan from a ventilation hole to diverge from a flow toward an exhaust port formed on a bearing guide side, and the portion of the cooling air flows toward an inlet and thereby circulates inside a housing. The branching passages through provided to the fan guide are formed so as to be inclined in the same direction as a circumferential direction so that air path resistance during actual operation (in an intermediate-speed region) does not increase.Type: GrantFiled: January 27, 2017Date of Patent: May 26, 2020Assignee: Koki Holdings Co., Ltd.Inventors: Akira Matsushita, Tomomasa Nishikawa, Noriyuki Horie, Masahiro Fujiwara
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Publication number: 20200161609Abstract: The electrical apparatus, in which a series connection state and a parallel connection state of an upper cell unit including five battery cells and a lower cell unit can be automatically switched by means of a difference in a terminal shape on the electrical apparatus body side, has a terminal holder and holds apparatus side terminals. The terminal holder, which establishes an electrically connected state with the connection terminals of the battery pack, is provided with two parallel protruding parts that extend in the forward-backward direction, and second rail grooves fitted to the protruding parts on the electrical apparatus side. Due to the fitting, relative movement of the terminal holder and the battery pack in the vertical direction can be suppressed, and wear on the apparatus side terminals can be greatly suppressed.Type: ApplicationFiled: June 29, 2018Publication date: May 21, 2020Applicant: Koki Holdings Co., Ltd.Inventors: Takuhiro Murakami, Tomomasa NISHIKAWA, Shinji Watanabe, Junpei SATO, Hikaru Tamura, Shota KANNO, Toshio Mizoguchi, Yasushi Nakano, Hiroyuki HANAWA, Kazuhiko FUNABASHI, Masayuki Ogura, Takuya Teranishi, Junichi Toukairin, Shota Takeuchi, Yusuke FUNABIKI
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Patent number: 10658957Abstract: A power tool includes a brushless motor, a supplying circuit, and a controller. The brushless motor is configured to drive and rotate when a voltage applied to the brushless motor is larger than or equal to an induced voltage. The supplying circuit is configured to apply a driving voltage to the brushless motor. The controller is configured to control the supplying circuit. The supplying circuit includes a rectifying circuit, a capacitor, and a switching circuit. The rectifying circuit is configured to rectify an alternating voltage and output a rectified voltage. The capacitor is configured to smooth the voltage inputted via the rectifying circuit. The switching circuit is configured to perform a switching operation based on a PWM signal to adjust a period during which the driving voltage is applied. The controller is configured to set a duty ratio within a prescribed range, and output the PWM signal of the set duty ratio to the switching circuit to control the switching operation.Type: GrantFiled: March 31, 2017Date of Patent: May 19, 2020Assignee: Koki Holdings Co., Ltd.Inventors: Shinji Kuragano, Takeru Kumakura
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Patent number: 10654153Abstract: In order to provide an impact tool which is capable of increasing a striking force in a rotational direction of being applied from a hammer to an anvil, the impact tool includes: an electric motor; an anvil which supports a work tool and is driven by the electric motor; and a hammer which applies the striking force in the rotational direction to the anvil. The impact tool is provided with: a spindle which is arranged to be concentric with the anvil, supports the hammer to be movable in an axial direction and the rotational direction with respect to the anvil, and transmits motive power of the electric motor to the anvil; and a control unit which controls rotation speed of the electric motor. The number of strokes of the anvil due to one rotation of the hammer differs in response to rotation speed of the electric motor.Type: GrantFiled: January 8, 2016Date of Patent: May 19, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventors: Takuhiro Murakami, Junichi Toukairin, Shota Takeuchi, Hironori Mashiko, Yuta Noguchi
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Publication number: 20200130127Abstract: An electric tool capable of achieving inhibition of reaction due to braking in good balance with inhibition of voltage jumping due to regenerated energy is provided. A grinder (1) is provided with a motor (6), an inverter circuit (43) for supplying electric current to the motor (6), and a controller (50) for controlling the inverter circuit (43). When generating an electric braking force on a motor (6), the rotation speed of which exceeds a specified rotation speed, the controller (50) performs a first braking control of continuously turning on lower arm-side switching elements (Q4-Q6) of the inverter circuit (43), after which the controller performs a second braking control of repeatedly turning on and off the lower arm-side switching elements (Q4-Q6).Type: ApplicationFiled: October 27, 2017Publication date: April 30, 2020Applicant: Koki Holdings Co., Ltd.Inventors: Takuya YOSHINARI, Kazutaka IWATA
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Patent number: 10632605Abstract: The disclosure provides a work tool having an electric motor, a power transmission means that receives motive power from the electric motor and transmits the motive power to a tip tool, a gear housing for accommodating at least a portion of the power transmission means, weights swingably supported on the gear housing, and coil springs that function as an urging means for urging the weights such that the weights are located at an initial neutral position, wherein the weights and the coil springs are provided respectively on the two sides of the gear housing so as to put the power transmission means therebetween, and a rotational support axle is provided that functions as a connecting means for connecting the weights provided on both sides of the gear housing so as to connect the weights such that the weights swing integrally.Type: GrantFiled: April 30, 2015Date of Patent: April 28, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventors: Daijiro Tanabe, Goya Fujimoto, Ryusuke Kobayashi, Kuniaki Kanbe, Shinichirou Satou
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Publication number: 20200127339Abstract: A battery pack which has cell units in which top-side and bottom-side battery cells are connected in series, and is capable of switching the connection state of the cell units, wherein a control unit monitors voltage imbalances between the cell units, and also monitors whether or not a cell unit contact failure has occurred. In order to stop a charging/discharging when a contact failure occurs, a signal (abnormality stoppage signal or charging stoppage signal) for stopping discharge is produced and outputted to the electrical device body-side.Type: ApplicationFiled: July 24, 2018Publication date: April 23, 2020Applicant: Koki Holdings Co., Ltd.Inventors: Yasushi Nakano, Satoshi YAMAGUCHI, Hiroyuki HANAWA, Kazuhiko FUNABASHI, Tomomasa NISHIKAWA, Shota KANNO, Toshio Mizoguchi
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Patent number: 10625354Abstract: An operator operates a throttle lever and by maximizing the extent of said operation, the drive state is initiated, and the crank shaft rotation rate R increases and reaches the maximal value (RC) thereof. Subsequently, the operator operates the dressing operation lever so as to be in a second state at elapsed time (t0) while keeping the extent of the throttle lever operation maximized. Because a microswitch is turned off, the crank shaft rotation rate (R) is controlled in a range of R1<R<R2. By placing the saw chain in contact with a grindstone fixed to the dressing operation lever simultaneously with said action, dressing work is performed. After the microswitch is turned off at elapsed time (t0), the output of an ignition coil is controlled cyclically by a control unit at a cycle (T1+T2) so as to be on (ignition) during period (T1) and off (flame off) during period (T2).Type: GrantFiled: April 15, 2016Date of Patent: April 21, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventors: Kenji Naganuma, Kouji Sagawa
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Patent number: 10630223Abstract: A power tool which brakes a motor without turning off a trigger switch when a trouble occurs in the motor is provided. The power tool (10) comprises: a motor (20) that rotates by supply of electricity from a power source (PS); a controller (38) for controlling the rotation of the motor; a switch (12) for switching on and off of power supply from the power source to the motor manually; first braking means (23) for braking the motor when the switch (12) is switched from on to off; and second braking means (23, 45) for braking the motor (20) on the basis of a prescribed signal from the controller when the switch (12) is in an on state.Type: GrantFiled: November 25, 2016Date of Patent: April 21, 2020Assignee: Koki Holdings Co., Ltd.Inventors: Satoshi Yamaguchi, Yoshikazu Kawano, Kazuhiko Funabashi
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Patent number: 10625407Abstract: In order to provide a driving machine which achieves reciprocating movements of a rack using a simple mechanism and is able to smoothly engage and disengage the rack by reducing the friction during engagement and disengagement of the rack, the driving machine is equipped with: a nose that extends in a prescribed direction; a housing that has the nose; a blade that has an engaging section, is movably guided in the housing in the prescribed direction, and is capable of driving a fastener via the nose; and a transmission mechanism that has an engaged section for engaging with the engaging section in order to transmit a driving force, wherein the transmission mechanism has a roller mechanism for guiding the engaging section and engaged section to disengage from each other.Type: GrantFiled: May 22, 2015Date of Patent: April 21, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventors: Shinichirou Sato, Yasuki Ohmori
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Patent number: 10618157Abstract: An electric power tool has a brushless motor for driving a tip tool, and a motor case is at least partly covered by a motor housing made of aluminum alloy and exposed to an outside. A control board provided with a control circuit for controlling the rotation of the brushless motor is disposed adjacent to the motor housing. The brushless motor and a control board are cooled by cooling air generated by a fun, thereby enhancing the cooling characteristics of the motor control circuit.Type: GrantFiled: December 18, 2014Date of Patent: April 14, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventors: Hideyuki Hashimoto, Atsuyuki Kikuchi, Shingo Yamazaki, Kuniaki Kanbe, Satoshi Abe, Daijiro Tanabe, Takehiro Ookubo
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Publication number: 20200094432Abstract: Providing a reciprocating tool capable of reducing vibrations generated during operations and improving work performance and processing precision. A reciprocating tool includes a transmission gear part 61 and a counter weight part 62. The transmission gear part 61 includes a bevel gear 611 and a weight 611A. The bevel gear 611 is rotatable in a first direction about an axis B by receiving a drive force of a motor 3. The weight 62A is rotatable in a second direction opposite to the first direction about the axis B by receiving the drive force of the motor 3. A center of gravity 61G of the transmission gear part 61 and a center of gravity 62G of the counter weight part 62 are separated farthest from a blade mounting part 8 when the blade mounting part 8 is positioned in a rearward position.Type: ApplicationFiled: April 27, 2018Publication date: March 26, 2020Applicant: KOKI HOLDINGS CO., LTD.Inventors: Tetsuya MONZEN, Ryosuke NAKANO
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Patent number: 10596679Abstract: Provided is an electric tool in which the risk of short-circuiting between conductive members of multiple installed switching elements has been reduced by providing partitioning plates between the switching elements. An electric tool, which has a motor, an inverter circuit with multiple switching elements for performing switching operations and controlling the driving of the motor, a control unit for controlling switching element on-off operations, and a circuit board on which the switching elements are loaded, is configured so that the circuit board is housed inside a container-shaped case (40) and the circuit board is secured with a partitioning member (50) that is interposed between the multiple switching elements and has partitioning plates (51, 52a, 52b) obtained from an insulating material.Type: GrantFiled: March 25, 2016Date of Patent: March 24, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventors: Yuuki Takeda, Hironori Sakai
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Patent number: 10569402Abstract: The disclosure discloses a driving machine includes a trigger, a first switch turned on or off by an operation of the trigger, a push lever that moves in response to an operation of pressing an ejection port of a fastener against a driven material, and a second switch turned on or off by movement of the push lever. The driving machine drives the fastener when the first switch and the second switch are both in the ON state. The trigger includes a switching mechanism to switch between a single-shot driving mode and a continuous-shot driving mode.Type: GrantFiled: January 24, 2017Date of Patent: February 25, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventors: Yoshimitsu Iijima, Hiroki Kitagawa
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Patent number: 10569405Abstract: Provided is an impact tool which can perform control in accordance with working situations. The impact tool converts a torque of a brushless motor into a striking force and applies it to a tip tool. The impact tool includes: a motor control unit which makes detection about whether the tip tool is pressed against an object during the rotation of the brushless motor; and a motor control unit which performs speed increase control for increasing the rotational speed of the brushless motor when a state of pressing the tip tool against the object has been detected continuously for a predetermined time.Type: GrantFiled: September 29, 2015Date of Patent: February 25, 2020Assignee: KOKI HOLDINGS CO., LTD.Inventor: Atsuyuki Kikuchi
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Publication number: 20200055159Abstract: Provided is a rotary tool. In the rotary tool, the rotating tip tool is mounted on a spindle by the fixture, and the spindle and the tip tool are rotated by a motor. The rotary tool has a switch which can switch the motor between a rotation state and a stop state, and a control device which controls the rotation of the motor corresponding to the operation of the switch. When the switch is turned off after a required time T elapses after the motor is started, the control device stops the rotary tool (104d, 106d) by performing a common braking operation on the spindle, and when the switch is turned off before the required time T elapses after the motor is started, the control device stops the tip tool (101d) by inertia without applying a braking force.Type: ApplicationFiled: February 23, 2018Publication date: February 20, 2020Applicant: Koki Holdings Co., Ltd.Inventors: Hironori SAKAI, Takuya YOSHINARI, Hironori Mashiko
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Patent number: D878886Type: GrantFiled: November 14, 2018Date of Patent: March 24, 2020Assignee: Koki Holdings Co., Ltd.Inventors: Shingo Kosugi, Shuji Takeda, Naoki Tadokoro