Patents by Inventor Itsuku Kato

Itsuku Kato 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: 12011813
    Abstract: An electric work machine (1; 110; 120; 130), such as a power tool, includes a motor (11) having a rotor, a drive part (13) that supplies electric currents to drive the motor, a rotational-direction selection part (17), and a motor-control part (14; 31, 32, 40, 50, 60; 14, 40, 60, 73, 80; 14, 60, 91). The rotational-direction selection part is configured for manually setting (selecting) the rotational direction of the rotor and outputs first and second setting signals that each indicate the set (selected) rotational direction. The motor-control part controls the drive part such that the rotor rotates in the rotational direction indicated by the first setting signal and/or the second setting signal. In response to a determination that the rotational directions indicated by the first and second setting signals are inconsistent, the motor-control part stops or prevents the drive of the motor.
    Type: Grant
    Filed: September 8, 2020
    Date of Patent: June 18, 2024
    Assignee: MAKITA CORPORATION
    Inventors: Hitoshi Suzuki, Seitaro Hayashi, Motohiro Omura, Itsuku Kato
  • Publication number: 20240123594
    Abstract: One aspect of the present disclosure provides an electric power tool including a motor, a drive circuit, a voltage detector, a first calculator, and a second calculator. The drive circuit applies a power-supply voltage to the motor in accordance with a first duty ratio. The voltage detector detects a magnitude of the power-supply voltage. The first calculator calculates a desired duty ratio based on the magnitude of the power-supply voltage detected. The second calculator increases the first duty ratio from an initial value to the desired duty ratio in accordance with a lapse of time. The second calculator varies a rate of increase of the first duty ratio based on the magnitude of the power-supply voltage detected.
    Type: Application
    Filed: October 13, 2023
    Publication date: April 18, 2024
    Applicant: MAKITA CORPORATION
    Inventors: Yuki HAYASHI, Itsuku KATO
  • Publication number: 20240091914
    Abstract: An electric power tool in one aspect of the present disclosure includes a motor, an output shaft, a drive circuit, a rotation controller, a calculator, and a deceleration controller. The output shaft is configured to attach a tool bit thereto, and be rotated by the motor. The rotation controller rotates the output shaft to thereby loosen a fastener from a fastened material. The calculator increases a determination value in accordance with a lapse of time from a first timing, and varies a rate of increase in the determination value in accordance with a speed parameter. The deceleration controller decelerates or stops the motor based on the determination value having reached a threshold value.
    Type: Application
    Filed: August 31, 2023
    Publication date: March 21, 2024
    Applicant: MAKITA CORPORATION
    Inventors: Shu ISAKA, Itsuku KATO
  • Patent number: 11806855
    Abstract: An electric power tool in one aspect of the present disclosure includes a motor, an impact mechanism, an impact detector, and a control circuit. The control circuit controls a motor current based on a drive duty ratio in a first driving term. The first driving term corresponds to a time period from when the motor is started until impact is detect. The drive duty ratio corresponds to a sum of a basic duty ratio and a proportional duty ratio. The control circuit controls the motor current so that an actual rotational speed of the motor is consistent with a target rotational speed after elapse of the first driving term.
    Type: Grant
    Filed: September 21, 2020
    Date of Patent: November 7, 2023
    Assignee: MAKITA CORPORATION
    Inventor: Itsuku Kato
  • Publication number: 20230336105
    Abstract: An electric working machine in one aspect of the present disclosure calculates an estimated heat value based on an electric current value and a parameter. The estimated heat value corresponds to an estimated heat generation amount of a motor. The electric current value corresponds to a magnitude of an electric current delivered from a power source to the motor. The electric work machine varies the parameter based on a load time. The load time corresponds to a time period during which a first load is continuously imposed on the motor. The first load has a specified magnitude or more. The electric work machine performs a protective operation for over temperature protection of the motor based on the estimated heat value having reached a heat threshold.
    Type: Application
    Filed: April 13, 2023
    Publication date: October 19, 2023
    Applicant: MAKITA CORPORATION
    Inventors: Dai SUZUKI, Masayuki OKAMURA, Itsuku KATO
  • Patent number: 11701759
    Abstract: An electric power tool in one aspect of the present disclosure includes a motor, an impact mechanism, and a control circuit. The control circuit executes a motor control process. The motor control process includes limiting an output of the motor in response to establishment of a preset condition. The preset condition is based on a load applied to the motor.
    Type: Grant
    Filed: September 21, 2020
    Date of Patent: July 18, 2023
    Assignee: MAKITA CORPORATION
    Inventors: Itsuku Kato, Yasuhito Kawai
  • Publication number: 20230144684
    Abstract: The electric work machine in one aspect of the present disclosure includes an output shaft, a motor, a current measuring circuit, and a controller. The current measuring circuit measures a current value, the current value corresponding to a magnitude of a drive current flowing through the motor. The controller sets a maximum value and a threshold. The controller calculates the correction value less than or equal to the maximum value so that the drive current decreases, in response to the current value having reached the threshold. The controller subtracts, from the control parameter, the correction value calculated, thereby correcting the control parameter. The controller drives the motor based on the control parameter corrected.
    Type: Application
    Filed: November 8, 2022
    Publication date: May 11, 2023
    Applicant: MAKITA CORPORATION
    Inventor: Itsuku KATO
  • Publication number: 20230069547
    Abstract: An electric work machine according to one aspect of the present disclosure includes a motor, a first connector, a second connector, an energizing circuit, a manual switch, and a controller. The controller outputs a first control signal to the energizing circuit to electrically connect the first connector to the motor, increases an actual rotational speed of the motor at a first rate, outputs the first control signal to the energizing circuit to electrically connect the second connector to the motor, and increases the actual rotational speed at a second rate. The second rate is less than the first rate.
    Type: Application
    Filed: August 23, 2022
    Publication date: March 2, 2023
    Applicant: MAKITA CORPORATION
    Inventor: Itsuku KATO
  • Publication number: 20230061013
    Abstract: An electric work machine includes a motor, a first connector, a second connector, an energizing circuit, a manual switch, and a controller. The controller electrically disconnects the first connector from the motor based on a first voltage value below a first threshold at a start of motor rotation. The controller maintains an electrical connection of the first connector to the motor based on the first voltage value below the first threshold and equal to or greater than a second threshold during discharge of the first battery.
    Type: Application
    Filed: August 24, 2022
    Publication date: March 2, 2023
    Applicant: MAKITA CORPORATION
    Inventor: Itsuku KATO
  • Patent number: 11571099
    Abstract: An interlocking adapter in one aspect of the present disclosure includes a current path, an electric load, a switch, and a controller. The controller turns on and off the switch in synchronization with a change of an alternating-current voltage received from an electric outlet of an electric apparatus in response to reception of an interlocking command signal from a working machine so as to supply a load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every ½ cycle of the alternating-current voltage.
    Type: Grant
    Filed: December 22, 2020
    Date of Patent: February 7, 2023
    Assignee: MAKITA CORPORATION
    Inventors: Hitoshi Suzuki, Yuki Kawai, Itsuku Kato, Yasutaka Hotta
  • Publication number: 20220371112
    Abstract: An electric work machine in one aspect of the present disclosure includes a motor, a manual switch, and a control circuit. The control circuit switches a preset control either to be enabled or disabled. During the preset control being enabled, the control circuit (i) varies an actual rotational speed of the motor in accordance with an actual moved distance of the manual switch and (ii) increases the actual rotational speed in response to a load being imposed on the motor. During the preset control being disabled, the control circuit varies the actual rotational speed in accordance with the actual moved distance of the manual switch in a manner at least partly distinctive from a variation in the actual rotational speed during the preset control being enabled.
    Type: Application
    Filed: May 23, 2022
    Publication date: November 24, 2022
    Applicant: MAKITA CORPORATION
    Inventors: Masayuki OKAMURA, Takuya KUSAKAWA, Itsuku KATO
  • Patent number: 11509129
    Abstract: An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.
    Type: Grant
    Filed: April 15, 2020
    Date of Patent: November 22, 2022
    Assignee: MAKITA CORPORATION
    Inventors: Yuki Kawai, Itsuku Kato
  • Patent number: 11213933
    Abstract: An electric working machine in one aspect of the present disclosure includes: a motor; a controller for controlling driving of the motor; a first setter; and a second setter. The first setter is operated for setting, as a control method for the motor, which is usable by the controller, one of control methods preliminarily registered. The second setter is operated for setting, as a control method for the motor, which is usable by the controller, at least one of the control methods settable via the first setter.
    Type: Grant
    Filed: October 11, 2018
    Date of Patent: January 4, 2022
    Assignee: MAKITA CORPORATION
    Inventors: Itsuku Kato, Akira Tomonaga, Katsuna Hayashi, Tokuo Hirabayashi, Tomoyuki Kondo
  • Patent number: 11161227
    Abstract: An electric working machine in one aspect of the present disclosure includes: a motor, a manipulator, a setter, and a controller. The setter sets first control characteristics preliminarily registered. The first control characteristics are set to achieve a rotational speed of the motor from a minimum rotational speed to a maximum rotational speed with a manipulating range of the manipulator, which is 50% or less of an effective manipulating range thereof.
    Type: Grant
    Filed: October 11, 2018
    Date of Patent: November 2, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Itsuku Kato, Akira Tomonaga, Katsuna Hayashi, Tokuo Hirabayashi, Tomoyuki Kondo
  • Publication number: 20210106194
    Abstract: An interlocking adapter in one aspect of the present disclosure includes a current path, an electric load, a switch, and a controller. The controller turns on and off the switch in synchronization with a change of an alternating-current voltage received from an electric outlet of an electric apparatus in response to reception of an interlocking command signal from a working machine so as to supply a load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every 1/2 cycle of the alternating-current voltage.
    Type: Application
    Filed: December 22, 2020
    Publication date: April 15, 2021
    Applicant: MAKITA CORPORATION
    Inventors: Hitoshi SUZUKI, Yuki KAWAI, Itsuku KATO, Yasutaka HOTTA
  • Publication number: 20210094158
    Abstract: An electric power tool in one aspect of the present disclosure includes a motor, an impact mechanism, and a control circuit. The control circuit executes a motor control process. The motor control process includes limiting an output of the motor in response to establishment of a preset condition. The preset condition is based on a load applied to the motor.
    Type: Application
    Filed: September 21, 2020
    Publication date: April 1, 2021
    Applicant: MAKITA CORPORATION
    Inventors: Itsuku KATO, Yasuhito KAWAI
  • Publication number: 20210094163
    Abstract: An electric power tool in one aspect of the present disclosure includes a motor, an impact mechanism, an impact detector, and a control circuit. The control circuit controls a motor current based on a drive duty ratio in a first driving term. The first driving term corresponds to a time period from when the motor is started until impact is detect. The drive duty ratio corresponds to a sum of a basic duty ratio and a proportional duty ratio. The control circuit controls the motor current so that an actual rotational speed of the motor is consistent with a target rotational speed after elapse of the first driving term.
    Type: Application
    Filed: September 21, 2020
    Publication date: April 1, 2021
    Applicant: MAKITA CORPORATION
    Inventor: Itsuku KATO
  • Publication number: 20210069886
    Abstract: An electric work machine (1; 110; 120; 130), such as a power tool, includes a motor (11) having a rotor, a drive part (13) that supplies electric currents to drive the motor, a rotational-direction selection part (17), and a motor-control part (14; 31, 32, 40, 50, 60; 14, 40, 60, 73, 80; 14, 60, 91). The rotational-direction selection part is configured for manually setting (selecting) the rotational direction of the rotor and outputs first and second setting signals that each indicate the set (selected) rotational direction. The motor-control part controls the drive part such that the rotor rotates in the rotational direction indicated by the first setting signal and/or the second setting signal. In response to a determination that the rotational directions indicated by the first and second setting signals are inconsistent, the motor-control part stops or prevents the drive of the motor.
    Type: Application
    Filed: September 8, 2020
    Publication date: March 11, 2021
    Inventors: Hitoshi SUZUKI, Seitaro HAYASHI, Motohiro OMURA, Itsuku KATO
  • Patent number: 10898041
    Abstract: An interlocking adapter in one aspect of the present disclosure includes a current path, an electric load, a switch, and a controller. The controller turns on and off the switch in synchronization with a change of an alternating-current voltage received from an electric outlet of an electric apparatus in response to reception of an interlocking command signal from a working machine so as to supply a load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every ½ cycle of the alternating-current voltage.
    Type: Grant
    Filed: December 26, 2018
    Date of Patent: January 26, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Hitoshi Suzuki, Yuki Kawai, Itsuku Kato, Yasutaka Hotta
  • Publication number: 20200244193
    Abstract: An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.
    Type: Application
    Filed: April 15, 2020
    Publication date: July 30, 2020
    Applicant: MAKITA CORPORATION
    Inventors: Yuki KAWAI, Itsuku KATO