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: 10658951
    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: July 24, 2017
    Date of Patent: May 19, 2020
    Assignee: MAKITA CORPORATION
    Inventors: Yuki Kawai, Itsuku Kato
  • Patent number: 10576971
    Abstract: A push cart includes a wheel, a motor, an obstacle detector, and a controller. The motor is configured to generate a rotational force that rotates the wheel. The obstacle detector is configured to detect an obstacle. The controller is configured to execute, in response to detection of the obstacle by the obstacle detector, avoidance control to control driving of the motor such that a movement of the push cart is limited. The controller is configured to disable execution of the avoidance control in response to a determination that a specified disabling condition is satisfied.
    Type: Grant
    Filed: June 29, 2018
    Date of Patent: March 3, 2020
    Assignee: MAKITA CORPORATION
    Inventors: Kouichi Takeda, Itsuku Kato, Jiro Suzuki
  • Patent number: 10541636
    Abstract: An electric working machine of an example of the present disclosure includes: a motor; a power supply portion; a controller; and a voltage detector. The power supply portion generates a DC voltage to drive the motor by rectifying an AC voltage supplied from an AC power source and smoothing by a capacitor. The controller controls energization of the motor. The voltage detector detects the AC voltage. The controller is configured to interrupt the energization when the voltage detector does not detect the AC voltage.
    Type: Grant
    Filed: April 11, 2017
    Date of Patent: January 21, 2020
    Assignee: MAKITA CORPORATION
    Inventors: Akihiro Nakamoto, Itsuku Kato, Yuki Kawai
  • Publication number: 20190319563
    Abstract: An electric power tool may include a three-phase brushless motor configured to drive a tool, a gear reducer provided between the motor and the tool. The gear reducer is configured to selectively change a reduction ratio from the motor to the tool between a first reduction ratio and a second reduction ratio. The electric power tool may further include a motor controller configured to drive the motor with rectangular waves. The motor controller is configured to selectively change a conduction angle of each rectangular wave between at least a first conduction angle and a second conduction angle.
    Type: Application
    Filed: April 10, 2019
    Publication date: October 17, 2019
    Inventors: Itsuku KATO, Katsuna HAYASHI, Kouichi TAKEDA, Hidenori NAGASAKA, Takeshi KAMIYA
  • Patent number: 10427284
    Abstract: A fastener driving tool is provided with a plunger, an impact spring, a motor, a drive mechanism, a motor drive control unit, a position detection unit, and a timer unit. The drive mechanism moves the plunger from a stop position to top dead center by rotation of the motor. The impact spring moves the plunger in a driving direction. The position detection unit detects that the plunger has reached a predetermined position by the rotation of the motor, and the timer unit measures time therebetween. The motor drive control unit, after power supply to the motor is cut off, performs a stop control for stopping the motor at the predetermined stop position based on the time measured by the timer unit.
    Type: Grant
    Filed: February 1, 2017
    Date of Patent: October 1, 2019
    Assignee: MAKITA CORPORATION
    Inventor: Itsuku Kato
  • Publication number: 20190207339
    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: Application
    Filed: December 26, 2018
    Publication date: July 4, 2019
    Applicant: MAKITA CORPORATION
    Inventors: Hitoshi SUZUKI, Yuki KAWAI, Itsuku KATO, Yasutaka HOTTA
  • Patent number: 10286534
    Abstract: A driving tool, such as a nailer, includes an electric motor, a crank mechanism driven by the electric motor, and a control apparatus for driving the electric motor. A crank-angle detection or calculation unit (109E) detects the crank angle of the crank mechanism or the motor in order to detect the operation state of the electric motor and a stopped time period of the motor is calculated from the crank angle. A sleep-control unit (109A) switches the driving tool between a sleep mode and a drive-enabled mode. If the stopped time period of the electric motor exceeds a prescribed time period, then the sleep-control unit (109A) switches the driving tool to the sleep mode. In the sleep mode, the electric current supplied to one or more of the control units constituting the control apparatus is reduced or cut off, thereby reducing the power consumption of the driving tool.
    Type: Grant
    Filed: April 14, 2015
    Date of Patent: May 14, 2019
    Assignee: MAKITA CORPORATION
    Inventor: Itsuku Kato
  • Publication number: 20190111550
    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: Application
    Filed: October 11, 2018
    Publication date: April 18, 2019
    Applicant: MAKITA CORPORATION
    Inventors: Itsuku KATO, Akira TOMONAGA, Katsuna HAYASHI, Tokuo HIRABAYASHI, Tomoyuki KONDO
  • Publication number: 20190111551
    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: Application
    Filed: October 11, 2018
    Publication date: April 18, 2019
    Applicant: MAKITA CORPORATION
    Inventors: Itsuku KATO, Akira TOMONAGA, Katsuna HAYASHI, Tokuo HIRABAYASHI, Tomoyuki KONDO
  • Publication number: 20190023265
    Abstract: A push cart includes a wheel, a motor, an obstacle detector, and a controller. The motor is configured to generate a rotational force that rotates the wheel. The obstacle detector is configured to detect an obstacle. The controller is configured to execute, in response to detection of the obstacle by the obstacle detector, avoidance control to control driving of the motor such that a movement of the push cart is limited. The controller is configured to disable execution of the avoidance control in response to a determination that a specified disabling condition is satisfied.
    Type: Application
    Filed: June 29, 2018
    Publication date: January 24, 2019
    Applicant: MAKITA CORPORATION
    Inventors: Kouichi TAKEDA, Itsuku KATO, Jiro SUZUKI
  • Patent number: 9943952
    Abstract: An electro-pneumatic tool drives a fastener into a workpiece by energizing an electric motor to drive a first piston and generate compressed air in a first cylinder. The compressed air is then supplied to a second cylinder and causes a second piston to move and drive the fastener into the workpiece. After the first piston has passed through its top dead center, braking is applied to the first piston according to one or more braking parameters. Then, if a control unit determines that the first piston has come to a stop at a position that is outside a predetermined range about the bottom dead center of the first piston, one or more of the braking parameters is changed in a subsequent fastener driving cycle to cause the first piston to stop closer to its bottom dead center after conclusion of the subsequent fastener driving cycle.
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: April 17, 2018
    Assignee: MAKITA CORPORATION
    Inventor: Itsuku Kato
  • Publication number: 20180034388
    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: July 24, 2017
    Publication date: February 1, 2018
    Applicant: MAKITA CORPORATION
    Inventors: Yuki KAWAI, Itsuku KATO
  • Publication number: 20170302211
    Abstract: An electric working machine of an example of the present disclosure includes: a motor; a power supply portion; a controller; and a voltage detector. The power supply portion generates a DC voltage to drive the motor by rectifying an AC voltage supplied from an AC power source and smoothing by a capacitor. The controller controls energization of the motor. The voltage detector detects the AC voltage. The controller is configured to interrupt the energization when the voltage detector does not detect the AC voltage.
    Type: Application
    Filed: April 11, 2017
    Publication date: October 19, 2017
    Applicant: MAKITA CORPORATION
    Inventors: Akihiro NAKAMOTO, Itsuku KATO, Yuki KAWAI
  • Publication number: 20170217004
    Abstract: A fastener driving tool is provided with a plunger, an impact spring, a motor, a drive mechanism, a motor drive control unit, a position detection unit, and a timer unit. The drive mechanism moves the plunger from a stop position to top dead center by rotation of the motor. The impact spring moves the plunger in a driving direction. The position detection unit detects that the plunger has reached a predetermined position by the rotation of the motor, and the timer unit measures time therebetween. The motor drive control unit, after power supply to the motor is cut off, performs a stop control for stopping the motor at the predetermined stop position based on the time measured by the timer unit.
    Type: Application
    Filed: February 1, 2017
    Publication date: August 3, 2017
    Applicant: MAKITA CORPORATION
    Inventor: Itsuku KATO
  • Patent number: 9543871
    Abstract: A motor-driven appliance of one aspect of the present disclosure includes a motor and a controller. The controller includes a physical quantity detector, a variation deriving portion, a loaded condition detector, and driving output portion. The physical quantity detector detects a physical quantity related to an operating state of the motor. The variation deriving portion derives a variation in the physical quantity based upon the physical quantity detected by the physical quantity detector. The loaded condition detector detects that the motor is under a loaded condition in which the motor is applied with a load based upon the variation derived by the variation deriving portion. The driving output portion generates the driving output corresponding to whether the loaded condition is detected by the loaded condition detector.
    Type: Grant
    Filed: August 1, 2014
    Date of Patent: January 10, 2017
    Assignee: MAKITA CORPORATION
    Inventor: Itsuku Kato
  • Patent number: 9438141
    Abstract: One aspect of an embodiment of the present disclosure is a braking apparatus for an electric power tool that includes a switching circuit with six switching elements and a brake control unit. The brake control unit switches any one selected switching element of three switching elements forming one selected switch group of a high-side switch group and a low-side switch group to an off state from an on state at a timing at which braking current flows through a diode connected in parallel to the selected switching element upon turn-off of the selected switching element.
    Type: Grant
    Filed: November 13, 2014
    Date of Patent: September 6, 2016
    Assignee: MAKITA CORPORATION
    Inventors: Goshi Ishikawa, Itsuku Kato
  • Patent number: 9276509
    Abstract: A power tool according to one aspect of one embodiment described in the disclosure includes a brushless motor, a battery voltage detection unit configured to detect a voltage of a battery that provides energy for driving the brushless motor, a rotational position detection unit configured to detect a rotational position of the brushless motor, and a control unit configured to control a drive output supplied to the brushless motor based at least in part on a signal from the rotational position detection unit. The control unit controls a current conduction angle and/or an advance angle supplied to the brushless motor so that, during control of the drive output to the brushless motor, a rotational speed or a conducting current of the brushless motor approaches or reaches a target value, the target value being based at least in part on a battery voltage detected by the battery voltage detection unit.
    Type: Grant
    Filed: January 28, 2014
    Date of Patent: March 1, 2016
    Assignee: MAKITA CORPORATION
    Inventors: Itsuku Kato, Motohiro Omura
  • Publication number: 20150298308
    Abstract: A driving tool, such as a nailer, includes an electric motor, a crank mechanism driven by the electric motor, and a control apparatus for driving the electric motor. A crank-angle detection or calculation unit (109E) detects the crank angle of the crank mechanism or the motor in order to detect the operation state of the electric motor and a stopped time period of the motor is calculated from the crank angle. A sleep-control unit (109A) switches the driving tool between a sleep mode and a drive-enabled mode. If the stopped time period of the electric motor exceeds a prescribed time period, then the sleep-control unit (109A) switches the driving tool to the sleep mode. In the sleep mode, the electric current supplied to one or more of the control units constituting the control apparatus is reduced or cut off, thereby reducing the power consumption of the driving tool.
    Type: Application
    Filed: April 14, 2015
    Publication date: October 22, 2015
    Inventor: Itsuku Kato
  • Publication number: 20150158160
    Abstract: An electro-pneumatic tool drives a fastener into a workpiece by energizing an electric motor to drive a first piston and generate compressed air in a first cylinder. The compressed air is then supplied to a second cylinder and causes a second piston to move and drive the fastener into the workpiece. After the first piston has passed through its top dead center, braking is applied to the first piston according to one or more braking parameters. Then, if a control unit determines that the first piston has come to a stop at a position that is outside a predetermined range about the bottom dead center of the first piston, one or more of the braking parameters is changed in a subsequent fastener driving cycle to cause the first piston to stop closer to its bottom dead center after conclusion of the subsequent fastener driving cycle.
    Type: Application
    Filed: December 10, 2014
    Publication date: June 11, 2015
    Inventor: Itsuku Kato
  • Publication number: 20150137717
    Abstract: One aspect of an embodiment of the present disclosure is a braking apparatus for an electric power tool that includes a switching circuit with six switching elements and a brake control unit. The brake control unit switches any one selected switching element of three switching elements forming one selected switch group of a high-side switch group and a low-side switch group to an off state from an on state at a timing at which braking current flows through a diode connected in parallel to the selected switching element upon turn-off of the selected switching element.
    Type: Application
    Filed: November 13, 2014
    Publication date: May 21, 2015
    Inventors: Goshi ISHIKAWA, Itsuku KATO