Patents by Inventor Yutaka Matsunaga

Yutaka Matsunaga 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).

  • Publication number: 20100163266
    Abstract: One aspect according to the present invention includes an electric power tool, in which a capacitor is positioned closer to a motor control circuit than a switch electrically connected to the motor control circuit.
    Type: Application
    Filed: December 24, 2009
    Publication date: July 1, 2010
    Applicant: MAKITA CORPORATION
    Inventors: Yutaka Matsunaga, Takuya Kusakawa, Motohiro Omura
  • Patent number: 7726412
    Abstract: A tightening tool for tightening a fastener is disclosed which comprises a motor and a main shaft that engages with the fastener. A clutch is disposed between the motor and the main shaft so that the clutch rotates the main shaft by transmitting torque from the motor to the main shaft when a load acting on the main shaft is less than a predetermined value. The clutch shuts off torque transmission from the motor to the main shaft when the load acting on the main shaft reaches or exceeds the predetermined value. When in use, the current flowing to the motor and rotation angle of the main shaft of the motor are detected. The detected current and rotation angle are used to determine whether the tightening torque of the fastener is normal.
    Type: Grant
    Filed: June 2, 2009
    Date of Patent: June 1, 2010
    Assignee: Makita Corporation
    Inventor: Yutaka Matsunaga
  • Publication number: 20100102102
    Abstract: In an electric drive tool which performs a driving operation with an electric motor as a driving source, the driving operation was performed previously by a first operation for moving a contact trip upward and a second operation for turning on a trigger, and it is desired to ensure prevention of an erroneous operation of the trigger. According to the present invention, prevention of an erroneous operation of the trigger is ensured. A lock lever (30) is provided in association with a trigger (4), and the trigger (4) is configured not to be turned on unless the third operation for unlocking the lock lever (30) is performed, so that it is ensured that an erroneous operation of the trigger (4) is prevented further reliably.
    Type: Application
    Filed: June 18, 2008
    Publication date: April 29, 2010
    Applicant: MAKITA CORPORATION
    Inventors: Yutaka Matsunaga, Hidekazu Suda, Shinji Hirabayashi
  • Publication number: 20100011926
    Abstract: A cutting machine of the present invention for cutting a material to be cut, which is placed on a table, with a rotating saw blade, includes an imaging device, a determination device and a stopping device. The imaging device takes a video image of an area on the table and outputs the video image. The determination device makes a determination on whether or not a number of pixels of a specific color, which is previously set, exceeds a predetermined threshold in one frame of image constituting the video image outputted from the imaging device. The stopping device stops rotation of the saw blade when it is determined by the determination device that the number of pixels of the specific color exceeds the predetermined threshold.
    Type: Application
    Filed: June 19, 2009
    Publication date: January 21, 2010
    Applicant: MAKITA CORPORATION
    Inventors: Kazuhito Murakami, Kazutoki Otake, Hiroshi Murata, Yutaka Matsunaga, Takeshi Nishimiya
  • Publication number: 20100001675
    Abstract: An electric power tool is provided that includes a motor as a driving source, a first operation switch, a first semiconductor switch, and a second semiconductor switch. The first operation switch is operated by a user to be turned ON/OFF. The first semiconductor switch, provided on a current path from the power source to the motor, includes at least one semiconductor switching device. When the first operation switch is OFF, the first semiconductor switch is turned OFF to interrupt the current path. When the first operation switch is ON, the first semiconductor switch is turned ON to close the current path. The second semiconductor switch is provided on the current path in series with the first semiconductor switch and includes at least one semiconductor switching device. The second semiconductor switch closes/interrupts the current path by being turned ON/OFF in accordance with an input control signal.
    Type: Application
    Filed: June 26, 2009
    Publication date: January 7, 2010
    Applicant: MAKITA CORPORATION
    Inventors: Yutaka Matsunaga, Hidekazu Suda, Takeshi Nishimiya
  • Publication number: 20090241744
    Abstract: A tightening tool for tightening a fastener is disclosed which comprises a motor and a main shaft that engages with the fastener. A clutch is disposed between the motor and the main shaft so that the clutch rotates the main shaft by transmitting torque from the motor to the main shaft when a load acting on the main shaft is less than a predetermined value. The clutch shuts off torque transmission from the motor to the main shaft when the load acting on the main shaft reaches or exceeds the predetermined value. When in use, the current flowing to the motor and rotation angle of the main shaft of the motor are detected. The detected current and rotation angle are used to determine whether the tightening torque of the fastener is normal.
    Type: Application
    Filed: June 2, 2009
    Publication date: October 1, 2009
    Inventor: YUTAKA MATSUNAGA
  • Publication number: 20090229957
    Abstract: An electrical power tool may include a switching device capable of controlling output power of a motor, a circuit board supporting the switching device, and a metal case receiving the circuit board. The switching device includes a conductive part and an insulated portion that is covered by an insulating covering material. The conductive part of the switching device contacts the circuit board The insulated portion of the switching device contacts the metal case via the insulating covering material.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 17, 2009
    Applicant: MAKITA CORPORATION
    Inventors: Takeshi Nishimiya, Yutaka Matsunaga
  • Patent number: 7556103
    Abstract: A fastening tool with a clutch for shutting off transmission of torque, capable of self-diagnosing fastening torque of a screw or the like at low cost without using expensive elements such as a torque sensor, etc. A fastening tool (10) has a motor (13), a main shaft (20) engaging with a screw or the like, and a clutch (14) interposed between the motor (13) and the main shaft (20). The clutch (14) transmits torque from the motor (13) to the main shaft (20) when a load acting on the main shaft (20) is less than a predetermined value, and shuts off torque transmission from the motor (13) to the main shaft (20) when a load acting on the main shaft (20) is equal to or greater than the predetermined value. The fastening tool (10) further has a control unit (60) for controlling the motor (13).
    Type: Grant
    Filed: March 10, 2005
    Date of Patent: July 7, 2009
    Assignee: Makita Corporation
    Inventor: Yutaka Matsunaga
  • Publication number: 20090051306
    Abstract: An electric power tool includes a direct current motor, at least one switching device, a trigger switch, a control unit, and a drive unit. The control unit sets a driving duty ratio for PWM controlling the direct current motor so as to increase the driving duty ratio in a stepwise manner in accordance with an operation continuation time of the trigger switch during a period from when an operation of the trigger switch is started until when a predetermined start-up time has elapsed.
    Type: Application
    Filed: August 13, 2008
    Publication date: February 26, 2009
    Applicant: MAKITA CORPORATION
    Inventors: Yutaka Matsunaga, Hirokatsu Yamamoto, Takuya Kusakawa
  • Publication number: 20080230245
    Abstract: A fastening tool with a clutch for shutting off transmission of torque, capable of self-diagnosing fastening torque of a screw or the like at low cost without using expensive means such as a torque sensor etc. A fastening tool (10) has a motor (13), a main shaft (20) engaging with a screw or the like, and a clutch (14) interposed between the motor (13) and the main shaft (20). The clutch (14) transmits torque from the motor (13) to the main shaft (20) when a load acting on the main shaft (20) is less than a predetermined value, and shuts off torque transmission from the motor (13) to the main shaft (20) when a load acting on the main shaft (20) is equal to or greater than the predetermined value. The fastening tool (10) further has a control unit (60) for controlling the motor (13).
    Type: Application
    Filed: March 10, 2005
    Publication date: September 25, 2008
    Inventor: Yutaka Matsunaga
  • Patent number: 7109675
    Abstract: Battery-powered tools may include battery 1 or battery pack BP and a drive source (e.g., motor M) for generating power using current supplied from the battery. A switch 3 may electrically connect the battery to the drive source. A voltage detector may detect the output battery voltage of the battery. Further, a processor 60, 210, a comparator 5 or another similar device preferably determines when a difference between (1) a first battery voltage detected at a first predetermined time period after the switch is turned OFF and (2) a second battery voltage detected at a second predetermined time after the first predetermined time period exceeds a predetermined value. This information may be utilized to determine whether to warn an operator of the battery powered tool that further operation using the battery 1 or battery pack BP should be discontinued.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: September 19, 2006
    Assignee: Makita Corporation
    Inventors: Yutaka Matsunaga, Hitoshi Suzuki, Goushi Ishikawa
  • Publication number: 20040263130
    Abstract: Battery-powered tools may include battery 1 or battery pack BP and a drive source (e.g., motor M) for generating power using current supplied from the battery. A switch 3 may electrically connect the battery to the drive source. A voltage detector may detect the output battery voltage of the battery. Further, a processor 60, 210, a comparator 5 or another similar device preferably determines when a difference between (1) a first battery voltage detected at a first predetermined time period after the switch is turned OFF and (2) a second battery voltage detected at a second predetermined time after the first predetermined time period exceeds a predetermined value. This information may be utilized to determine whether to warn an operator of the battery powered tool that further operation using the battery 1 or battery pack BP should be discontinued.
    Type: Application
    Filed: July 2, 2004
    Publication date: December 30, 2004
    Applicant: Makita
    Inventors: Yutaka Matsunaga, Hitoshi Suzuki, Goushi Ishikawa
  • Patent number: 6771043
    Abstract: Battery-powered tools may include battery 1 or battery pack BP and a drive source (e.g., motor M) for generating power using current supplied from the battery. A switch 3 may electrically connect the battery to the drive source. A voltage detector may detect the output battery voltage of the battery. Further, a processor 60, 210, a comparator 5 or another similar device preferably determines when a difference between (1) a first battery voltage detected at a first predetermined time period after the switch is turned OFF and (2) a second battery voltage detected at a second predetermined time after the first predetermined time period exceeds a predetermined value. This information may be utilized to determine whether to warn an operator of the battery powered tool that further operation using the battery 1 or battery pack BP should be discontinued.
    Type: Grant
    Filed: May 8, 2002
    Date of Patent: August 3, 2004
    Assignee: Makita Corporation
    Inventors: Yutaka Matsunaga, Hitoshi Suzuki, Goushi Ishikawa
  • Patent number: 6511200
    Abstract: Power tools are taught having a motor M1, a tool 1 coupled to the motor M1 via a tool holder 2, at least one light 4 disposed proximal to the tool 1, a switch 6 coupled to the motor M1 and the light 4, the switch 6 being capable of activation by an operator, a power supply 7 coupled to the switch 6, and a timer circuit 3 coupled to the light 4, the switch 6 and the power supply 7. Preferably, activation of the switch 6 causes the motor M1 and the light 4 to operate and the timer circuit 3 causes the light 4 to remain lit for a predetermined amount of time after either (1) the switch 6 has been activated or (2) the switch 6 has been deactivated subsequent to being activated. The timer circuit 3 can be, for example, a RC timer circuit 11 or a microprocessor 15. The light 4 may be an LED. The power supply 7 can be a rechargeable battery Ba.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: January 28, 2003
    Assignee: Makita Corporation
    Inventor: Yutaka Matsunaga
  • Publication number: 20020175656
    Abstract: Battery-powered tools may include battery 1 or battery pack BP and a drive source (e.g., motor M) for generating power using current supplied from the battery. A switch 3 may electrically connect the battery to the drive source. A voltage detector may detect the output battery voltage of the battery. Further, a processor 60, 210, a comparator 5 or another similar device preferably determines when a difference between (1) a first battery voltage detected at a first predetermined time period after the switch is turned OFF and (2) a second battery voltage detected at a second predetermined time after the first predetermined time period exceeds a predetermined value. This information may be utilized to determine whether to warn an operator of the battery powered tool that further operation using the battery 1 or battery pack BP should be discontinued.
    Type: Application
    Filed: May 8, 2002
    Publication date: November 28, 2002
    Applicant: Makita Corporation
    Inventors: Yutaka Matsunaga, Hitoshi Suzuki, Goushi Ishikawa
  • Publication number: 20020048166
    Abstract: Power tools are taught having a motor M1, a tool 1 coupled to the motor M1 via a tool holder 2, at least one light 4 disposed proximal to the tool 1, a switch 6 coupled to the motor M1 and the light 4, the switch 6 being capable of activation by an operator, a power supply 7 coupled to the switch 6, and a timer circuit 3 coupled to the light 4, the switch 6 and the power supply 7. Preferably, activation of the switch 6 causes the motor M1 and the light 4 to operate and the timer circuit 3 causes the light 4 to remain lit for a predetermined amount of time after either (1) the switch 6 has been activated or (2) the switch 6 has been deactivated subsequent to being activated. The timer circuit 3 can be, for example, a RC timer circuit 11 or a microprocessor 15. The light 4 may be an LED. The power supply 7 can be a rechargeable battery Ba.
    Type: Application
    Filed: September 12, 2001
    Publication date: April 25, 2002
    Applicant: MAKITA CORPORATION
    Inventor: Yutaka Matsunaga
  • Patent number: 6353705
    Abstract: A speed control circuit of a direct current motor comprises a switching regulator IC 10. The switching regulator IC 10 is composed of a reference voltage generator 12 which generates a reference voltage of 5V, a first operational amplifier OP1, a second operational amplifier OP2, a third operational amplifier OP3, a triangular wave generator 14 which generates a triangular wave, and a transistor TR1. The speed control circuit is constructed using a general switching regulator IC; therefore, it is possible to cheaply and readily manufacture the speed control circuit of the direct current motor.
    Type: Grant
    Filed: July 26, 1999
    Date of Patent: March 5, 2002
    Assignee: Makita Corporation
    Inventors: John Capps, Yutaka Matsunaga
  • Patent number: 6318874
    Abstract: Power tools are taught having a motor M1, a tool 1 coupled to the motor M1 via a tool holder 2, at least one light 4 disposed proximal to the tool 1, a switch 6 coupled to the motor M1 and the light 4, the switch 6 being capable of activation by an operator, a power supply 7 coupled to the switch 6, and a timer circuit 3 coupled to the light 4, the switch 6 and the power supply 7. Preferably, activation of the switch 6 causes the motor M1 and the light 4 to operate and the timer circuit 3 causes the light 4 to remain lit for a predetermined amount of time after either (1) the switch 6 has been activated or (2) the switch 6 has been deactivated subsequent to being activated. The timer circuit 3 can be, for example, a RC timer circuit 11 or a microprocessor 15. The light 4 may be an LED. The power supply 7 can be a rechargeable battery Ba.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: November 20, 2001
    Assignee: Makita Corporation
    Inventor: Yutaka Matsunaga
  • Patent number: 6229280
    Abstract: A charging system includes an electric power tool (2) and a charger (1) having internal rechargeable batteries (6) and a controller (9) for monitoring the charge/discharge level of the batteries (6). The electric power tool (2) additionally includes a pair of charge terminals (13a, 14a) for carrying current to charge the batteries (6), a temperature terminal (15a) for outputting to the charger (1) data on the temperature of the batteries, and a data terminal (16a) for outputting to the charger data on the battery charge/discharge level from the controller (9). The charger (1) includes a pair of charge terminals (13b, 14b), a temperature terminal (15b), and a data terminal (16b) that are electrically connected to the corresponding tool terminals when the tool (2) is set on the charger for a charge.
    Type: Grant
    Filed: March 18, 1999
    Date of Patent: May 8, 2001
    Assignees: Makita Corporation, Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Masahiko Sakoh, Masatoshi Sugiura, Yutaka Matsunaga, Tomoo Muramatsu, Kazuyoshi Horikawa
  • Patent number: 6191554
    Abstract: An improved charging system for preventing battery deterioration and for accurate indication of the remaining battery charge level includes an electric power tool (2) and a charger (1). The electric power tool (2) is provided with an internal rechargeable batteries (6) and a second controller (9). The charger (1) is provided with circuitry for charging, a microcomputer (19), and discharge circuitry which is comprised of a manually-operated battery refreshing button (25), a discharge relay (23) and a discharge resistor (24). Upon depression of the battery refreshing button (25), the microcomputer (19) causes the batteries (6) of the electric power tool (2) to be charged to a full level and discharged to a predetermined level twice. When the two-cycle operation of full charge and discharge is completed, the second controller (9) of the electric power tool (2) updates the remaining charge level of the batteries (6).
    Type: Grant
    Filed: July 2, 1999
    Date of Patent: February 20, 2001
    Assignees: Makita Corporation, Hondas Giken Kogyo Kabushiki
    Inventors: Shinichi Nakane, Yutaka Matsunaga, Tomoo Muramatsu, Kazuyoshi Horikawa