Patents by Inventor Kenichirou Yoshida
Kenichirou Yoshida has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10391599Abstract: There is provided an electric power tool having a plurality of operation modes with different rotation speeds at least in a predetermined load range. The electric power tool is capable of switching between the operation modes when a predetermined condition is satisfied even during a motor is driven, and configured such that a rotation speed of the motor is changed smoothly or in a stepwise manner at the switching between the operation modes.Type: GrantFiled: July 10, 2014Date of Patent: August 27, 2019Assignee: KOKI HOLDINGS CO., LTD.Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano, Takuya Konnai
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Patent number: 10205198Abstract: A power tool includes a motor and control means for controlling the motor. The motor is capable of being driven by power supplied from a battery pack including a battery cell. The control means is configured to continue to rotate the motor even when a motor-halt signal is inputted from the battery pack. With this structure, the power tool can be used continuously without need to halt rotation of the motor, even when receiving a halt signal, such as an overdischarge detection signal or an overcurrent detection signal.Type: GrantFiled: May 22, 2015Date of Patent: February 12, 2019Assignee: Koki Holdings Co., Ltd.Inventors: Yoshikazu Kawano, Nobuhiro Takano, Toshiaki Koizumi, Kazuhiko Funabashi, Kenichirou Yoshida, Takao Aradachi
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Patent number: 10201865Abstract: A portable electric cutter includes a housing in which a motor is accommodated, a saw blade driven to rotate by the motor, a base coupled to the housing and having a bottom surface slidable on a surface of a material to be cut, a fan driven to rotate by the motor, a driving circuit for switching power supplied to the motor, and a control circuit for controlling the driving circuit. A circuit board on which the driving circuit, the control circuit and others are mounted is provided, motor cooling air vents are provided in the housing on a side opposite to the saw blade, and circuit board cooling air vents are provided in the housing on the side opposite to the saw blade.Type: GrantFiled: October 2, 2017Date of Patent: February 12, 2019Assignee: Koki Holdings Co., Ltd.Inventors: Hayato Yamaguchi, Hideyuki Tanimoto, Kenichirou Yoshida, Shinji Kuragano
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Patent number: 10099303Abstract: An electric power tool includes a brushless motor, a control unit configured to control power supply to the brushless motor, a rotary tool configured to be rotated by the brushless motor, a rotation speed detecting unit configured to detect a rotation speed of the brushless motor, a main switch configured to transmit, to the control unit, an ON/OFF signal for switching between driving and stopping of the brushless motor, and a mode switching unit configured to transmit, to the control unit, a mode switching signal for switching between multiple modes of rotation control of the brushless motor, the control unit is configured to perform the rotation control of the brushless motor in any one of the multiple modes including at least a high-speed mode and a low-speed mode.Type: GrantFiled: August 4, 2014Date of Patent: October 16, 2018Assignee: HITACHI KOKI CO., LTD.Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano
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Patent number: 10027196Abstract: An electric tool includes a brushless motor having a plurality of phases, the brushless motor. The brushless motor includes a plurality of stator coils connected in parallel with each of the plurality of phases, and a plurality of crossover wires, each of the crossover wires being configured to electrically connect the plurality of stator coils for each of the plurality of phases to each other. The plurality of crossover wires for the plurality of phases are electrically connected to each other.Type: GrantFiled: February 14, 2015Date of Patent: July 17, 2018Assignee: HITACHI KOKI CO., LTD.Inventors: Kenichirou Yoshida, Shinji Kuragano
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Publication number: 20180021865Abstract: A portable electric cutter includes a housing in which a motor is accommodated, a saw blade driven to rotate by the motor, a base coupled to the housing and having a bottom surface slidable on a surface of a material to be cut, a fan driven to rotate by the motor, a driving circuit for switching power supplied to the motor, and a control circuit for controlling the driving circuit. A circuit board on which the driving circuit, the control circuit and others are mounted is provided, motor cooling air vents are provided in the housing on a side opposite to the saw blade, and circuit board cooling air vents are provided in the housing on the side opposite to the saw blade.Type: ApplicationFiled: October 2, 2017Publication date: January 25, 2018Inventors: Hayato YAMAGUCHI, Hideyuki TANIMOTO, Kenichirou YOSHIDA, Shinji KURAGANO
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Patent number: 9808872Abstract: A portable electric cutter includes a housing 2 in which a motor 1 is accommodated, a saw blade driven to rotate by the motor, a base 6 coupled to the housing 2 and having a bottom surface slidable on a surface of a material to be cut, a fan 7 driven to rotate by the motor, a driving circuit for switching power supplied to the motor, and a control circuit for controlling the driving circuit. A circuit board 60 on which the driving circuit, the control circuit and others are mounted is provided, motor cooling air vents are provided in the housing 2 on a side opposite to the saw blade, and circuit board cooling air vents are provided in the housing 2 on the side opposite to the saw blade.Type: GrantFiled: March 13, 2013Date of Patent: November 7, 2017Assignee: HITACHI KOKI CO., LTD.Inventors: Hayato Yamaguchi, Hideyuki Tanimoto, Kenichirou Yoshida, Shinji Kuragano
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Publication number: 20170194670Abstract: A power tool includes a motor and control means for controlling the motor. The motor is capable of being driven by power supplied from a battery pack including a battery cell. The control means is configured to continue to rotate the motor even when a motor-halt signal is inputted from the battery pack. With this structure, the power tool can be used continuously without need to halt rotation of the motor, even when receiving a halt signal, such as an overdischarge detection signal or an overcurrent detection signal.Type: ApplicationFiled: May 22, 2015Publication date: July 6, 2017Inventors: Yoshikazu KAWANO, Nobuhiro TAKANO, Toshiaki KOIZUMI, Kazuhiko FUNABASHI, Kenichirou YOSHIDA, Takao ARADACHI
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Patent number: 9570952Abstract: A disk motor including: a rotor; a stator; an output shaft concentrically fixed to the rotor; at least one coil disk which is provided to one of the rotor or the stator, a coil pattern which includes a plurality of radial patterns or radial pattern groups extending outwards in a radial direction from a center part of the coil disk being formed on at least one surface of the coil disk; an electric current supply portion which supplies electric current to the coil pattern; a magnetic flux generating portion which is provided to another of the rotor or the stator and faces the coil pattern; and an intermediate pattern which is formed between adjacent radial patterns or adjacent radial pattern groups on the coil disk.Type: GrantFiled: January 31, 2012Date of Patent: February 14, 2017Assignee: HITACHI KOKI CO., LTD.Inventors: Kenichirou Yoshida, Hideyuki Tanimoto
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Patent number: 9391491Abstract: A power tool includes a housing, a brushless motor, and a cover member. The housing has an air intake hole and an air exhaust hole formed therein, the housing having an inner surface. The brushless motor has an outer surface disposed in the housing, a first endface near the air intake hole, and a second endface near the air exhaust hole. The cover member covers at least one of the first endface and the second endface for preventing dust from entering the brushless motor. The inner surface of the housing and outer surface of the brushless motor define a circulation path providing communication between the air intake hole and the air exhaust hole.Type: GrantFiled: September 20, 2013Date of Patent: July 12, 2016Assignee: HITACHI KOKI CO., LTD.Inventors: Kenichirou Yoshida, Katsuhiro Oomori, Yoshihiro Komuro, Kazutaka Iwata
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Publication number: 20160193673Abstract: An electric power tool includes a brushless motor, a control unit configured to control power supply to the brushless motor, a rotary tool configured to be rotated by the brushless motor, a rotation speed detecting unit configured to detect a rotation speed of the brushless motor, a main switch configured to transmit, to the control unit, an ON/OFF signal for switching between driving and stopping of the brushless motor, and a mode switching unit configured to transmit, to the control unit, a mode switching signal for switching between multiple modes of rotation control of the brushless motor, the control unit is configured to perform the rotation control of the brushless motor in any one of the multiple modes including at least a high-speed mode and a low-speed mode.Type: ApplicationFiled: August 4, 2014Publication date: July 7, 2016Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano
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Patent number: 9197153Abstract: A power tool includes a housing, an electric motor accommodated in the housing, a secondary battery that supplies electric power to the electric motor, a handle provided at the housing, a trigger switch provided at the handle for controlling electric power supply to the electric motor, a residual capacity display for displaying a residual capacity of the secondary battery, and a lock-release switch provided at the handle and configured to allow the trigger switch to be operable and to start displaying the residual capacity at the residual capacity display upon manipulation to the lock-release switch.Type: GrantFiled: July 22, 2013Date of Patent: November 24, 2015Assignee: Hitachi Koki Co., Ltd.Inventors: Kenichirou Yoshida, Hideyuki Tanimoto, Hayato Yamaguchi, Shinji Kuragano, Takuya Konnai
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Publication number: 20150244226Abstract: An electric tool includes a brushless motor having a plurality of phases, the brushless motor. The brushless motor includes a plurality of stator coils connected in parallel with each of the plurality of phases, and a plurality of crossover wires, each of the crossover wires being configured to electrically connect the plurality of stator coils for each of the plurality of phases to each other. The plurality of crossover wires for the plurality of phases are electrically connected to each other.Type: ApplicationFiled: February 14, 2015Publication date: August 27, 2015Inventors: Kenichirou YOSHIDA, Shinji KURAGANO
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Patent number: 9114519Abstract: A current detection circuit (18) detects that a drive current of the stator coil (2d) is exceeding a threshold value Ir. A rotation number detection circuit (17) detects that the number of rotations of a rotor (2a) is lower than a threshold value Nr. A computing part (20) outputs a PWM signal which switches a semiconductor switching element (3a) of the inverter circuit part (3). The computing part (20) changes the threshold values Ir and Nr in accordance with the PWM duty of the PWM signal determined in accordance with a pressed distance of a switch trigger (7) and detects a locked state of the motor (2) on the conditions that the motor current I is exceeding the set threshold value Ir and that the number of rotations N thereof is lower than the threshold value Nr.Type: GrantFiled: February 16, 2009Date of Patent: August 25, 2015Assignee: HITACHI KOKI CO., LTD.Inventors: Kazutaka Iwata, Kenichirou Yoshida, Shinji Watanabe
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Publication number: 20150034348Abstract: There is provided an electric power tool having a plurality of operation modes with different rotation speeds at least in a predetermined load range. The electric power tool is capable of switching between the operation modes when a predetermined condition is satisfied even during a motor is driven, and configured such that a rotation speed of the motor is changed smoothly or in a stepwise manner at the switching between the operation modes.Type: ApplicationFiled: July 10, 2014Publication date: February 5, 2015Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano, Takuya Konnai
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Publication number: 20150026985Abstract: A portable electric cutter includes a housing 2 in which a motor 1 is accommodated, a saw blade driven to rotate by the motor, a base 6 coupled to the housing 2 and having a bottom surface slidable on a surface of a material to be cut, a fan 7 driven to rotate by the motor, a driving circuit for switching power supplied to the motor, and a control circuit for controlling the driving circuit. A circuit board 60 on which the driving circuit, the control circuit and others are mounted is provided, motor cooling air vents are provided in the housing 2 on a side opposite to the saw blade, and circuit board cooling air vents are provided in the housing 2 on the side opposite to the saw blade.Type: ApplicationFiled: March 13, 2013Publication date: January 29, 2015Inventors: Hayato Yamaguchi, Hideyuki Tanimoto, Kenichirou Yoshida, Shinji Kuragno
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Publication number: 20140028223Abstract: A power tool includes a housing, an electric motor accommodated in the housing, a secondary battery that supplies electric power to the electric motor, a handle provided at the housing, a trigger switch provided at the handle for controlling electric power supply to the electric motor, a residual capacity display for displaying a residual capacity of the secondary battery, and a lock-release switch provided at the handle and configured to allow the trigger switch to be operable and to start displaying the residual capacity at the residual capacity display upon manipulation to the lock-release switch.Type: ApplicationFiled: July 22, 2013Publication date: January 30, 2014Applicant: HITACHI KOKI CO., LTD.Inventors: Kenichirou Yoshida, Hideyuki Tanimoto, Hayato Yamaguchi, Shinji Kuragano, Takuya Konnai
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Publication number: 20140015350Abstract: A power tool includes a housing, a brushless motor, and a cover member. The housing has an air intake hole and an air exhaust hole formed therein, the housing having an inner surface. The brushless motor has an outer surface disposed in the housing, a first endface near the air intake hole, and a second endface near the air exhaust hole. The cover member covers at least one of the first endface and the second endface for preventing dust from entering the brushless motor. The inner surface of the housing and outer surface of the brushless motor define a circulation path providing communication between the air intake hole and the air exhaust hole.Type: ApplicationFiled: September 20, 2013Publication date: January 16, 2014Applicant: Hitachi KoKi Co., Ltd.Inventors: Kenichirou Yoshida, Katsuhiro Oomori, Yoshihiro Komuro, Kazutaka Iwata
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Publication number: 20130307367Abstract: A disk motor including: a rotor; a stator; an output shaft concentrically fixed to the rotor; at least one coil disk which is provided to one of the rotor or the stator, a coil pattern which includes a plurality of radial patterns or radial pattern groups extending outwards in a radial direction from a center part of the coil disk being formed on at least one surface of the coil disk; an electric current supply portion which supplies electric current to the coil pattern; a magnetic flux generating portion which is provided to another of the rotor or the stator and faces the coil pattern; and an intermediate pattern which is formed between adjacent radial patterns or adjacent radial pattern groups on the coil disk.Type: ApplicationFiled: January 31, 2012Publication date: November 21, 2013Applicant: HITACHI KOKI CO., LTD.Inventors: Kenichirou Yoshida, Hideyuki Tanimoto
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Patent number: 8541913Abstract: A power tool includes a housing, a brushless motor, and a cover member. The housing has an air intake hole and an air exhaust hole formed therein, the housing having an inner surface. The brushless motor has an outer surface disposed in the housing, a first endface near the air intake hole, and a second endface near the air exhaust hole. The cover member covers at least one of the first endface and the second endface for preventing dust from entering the brushless motor. The inner surface of the housing and outer surface of the brushless motor define a circulation path providing communication between the air intake hole and the air exhaust hole.Type: GrantFiled: April 13, 2012Date of Patent: September 24, 2013Assignee: Hitachi Koki Co., Ltd.Inventors: Kenichirou Yoshida, Katsuhiro Oomori, Yoshihiro Komuro, Kazutaka Iwata