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).

  • Patent number: 10391599
    Abstract: 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: Grant
    Filed: July 10, 2014
    Date of Patent: August 27, 2019
    Assignee: KOKI HOLDINGS CO., LTD.
    Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano, Takuya Konnai
  • Patent number: 10205198
    Abstract: 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: Grant
    Filed: May 22, 2015
    Date of Patent: February 12, 2019
    Assignee: Koki Holdings Co., Ltd.
    Inventors: Yoshikazu Kawano, Nobuhiro Takano, Toshiaki Koizumi, Kazuhiko Funabashi, Kenichirou Yoshida, Takao Aradachi
  • Patent number: 10201865
    Abstract: 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: Grant
    Filed: October 2, 2017
    Date of Patent: February 12, 2019
    Assignee: Koki Holdings Co., Ltd.
    Inventors: Hayato Yamaguchi, Hideyuki Tanimoto, Kenichirou Yoshida, Shinji Kuragano
  • Patent number: 10099303
    Abstract: 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: Grant
    Filed: August 4, 2014
    Date of Patent: October 16, 2018
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano
  • Patent number: 10027196
    Abstract: 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: Grant
    Filed: February 14, 2015
    Date of Patent: July 17, 2018
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Kenichirou Yoshida, Shinji Kuragano
  • Publication number: 20180021865
    Abstract: 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: Application
    Filed: October 2, 2017
    Publication date: January 25, 2018
    Inventors: Hayato YAMAGUCHI, Hideyuki TANIMOTO, Kenichirou YOSHIDA, Shinji KURAGANO
  • Patent number: 9808872
    Abstract: 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: Grant
    Filed: March 13, 2013
    Date of Patent: November 7, 2017
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Hayato Yamaguchi, Hideyuki Tanimoto, Kenichirou Yoshida, Shinji Kuragano
  • Publication number: 20170194670
    Abstract: 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: Application
    Filed: May 22, 2015
    Publication date: July 6, 2017
    Inventors: Yoshikazu KAWANO, Nobuhiro TAKANO, Toshiaki KOIZUMI, Kazuhiko FUNABASHI, Kenichirou YOSHIDA, Takao ARADACHI
  • Patent number: 9570952
    Abstract: 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: Grant
    Filed: January 31, 2012
    Date of Patent: February 14, 2017
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Kenichirou Yoshida, Hideyuki Tanimoto
  • Patent number: 9391491
    Abstract: 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: Grant
    Filed: September 20, 2013
    Date of Patent: July 12, 2016
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Kenichirou Yoshida, Katsuhiro Oomori, Yoshihiro Komuro, Kazutaka Iwata
  • Publication number: 20160193673
    Abstract: 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: Application
    Filed: August 4, 2014
    Publication date: July 7, 2016
    Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano
  • Patent number: 9197153
    Abstract: 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: Grant
    Filed: July 22, 2013
    Date of Patent: November 24, 2015
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Kenichirou Yoshida, Hideyuki Tanimoto, Hayato Yamaguchi, Shinji Kuragano, Takuya Konnai
  • Publication number: 20150244226
    Abstract: 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: Application
    Filed: February 14, 2015
    Publication date: August 27, 2015
    Inventors: Kenichirou YOSHIDA, Shinji KURAGANO
  • Patent number: 9114519
    Abstract: 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: Grant
    Filed: February 16, 2009
    Date of Patent: August 25, 2015
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Kazutaka Iwata, Kenichirou Yoshida, Shinji Watanabe
  • Publication number: 20150034348
    Abstract: 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: Application
    Filed: July 10, 2014
    Publication date: February 5, 2015
    Inventors: Kenichirou Yoshida, Akira Onose, Shinji Kuragano, Takuya Konnai
  • Publication number: 20150026985
    Abstract: 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: Application
    Filed: March 13, 2013
    Publication date: January 29, 2015
    Inventors: Hayato Yamaguchi, Hideyuki Tanimoto, Kenichirou Yoshida, Shinji Kuragno
  • Publication number: 20140028223
    Abstract: 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: Application
    Filed: July 22, 2013
    Publication date: January 30, 2014
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Kenichirou Yoshida, Hideyuki Tanimoto, Hayato Yamaguchi, Shinji Kuragano, Takuya Konnai
  • Publication number: 20140015350
    Abstract: 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: Application
    Filed: September 20, 2013
    Publication date: January 16, 2014
    Applicant: Hitachi KoKi Co., Ltd.
    Inventors: Kenichirou Yoshida, Katsuhiro Oomori, Yoshihiro Komuro, Kazutaka Iwata
  • Publication number: 20130307367
    Abstract: 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: Application
    Filed: January 31, 2012
    Publication date: November 21, 2013
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Kenichirou Yoshida, Hideyuki Tanimoto
  • Patent number: 8541913
    Abstract: 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: Grant
    Filed: April 13, 2012
    Date of Patent: September 24, 2013
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Kenichirou Yoshida, Katsuhiro Oomori, Yoshihiro Komuro, Kazutaka Iwata