Patents by Inventor Takuya Kusakawa

Takuya Kusakawa 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: 9073186
    Abstract: An electric power tool includes a motor, a current detection unit, an operating portion, a current threshold setting unit and a control unit. The current threshold setting unit sets a current threshold so as to change in accordance with changes in a motor current which flows when the motor is started as usual until a predetermined period of time elapses since the control unit has started driving of the motor. When the predetermined period of time has elapsed, the current threshold setting unit fixes the current threshold to a constant value which corresponds to a set torque.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: July 7, 2015
    Assignee: MAKITA CORPORATION
    Inventor: Takuya Kusakawa
  • Publication number: 20150158157
    Abstract: An electric power tool to tighten a screw while drilling a hole with the screw in a tightening-target-object includes a motor as a drive source. A motor control unit controls the motor such that the rotation number of the motor is a rotation number according to specifics of an operation input received by an operation receiving unit with a preset maximum rotation number as an upper limit. At a start-up of the motor, the maximum rotation number is set to a first maximum rotation number. When it is detected that a hole has been drilled in the tightening-target-object with the screw after the start-up of the motor, the maximum rotation number is set to a second maximum rotation number lower than the first maximum rotation number. The second maximum rotation number is set according to a material thickness so as to become lower as the material thickness is smaller.
    Type: Application
    Filed: May 31, 2013
    Publication date: June 11, 2015
    Inventors: Tokuo Hirabayashi, Ryunosuke Kumagai, Takeshi Nishimiya, Goshi Ishikawa, Takuya Kusakawa
  • Publication number: 20150144365
    Abstract: A rotary impact tool according to one aspect of the present invention includes a motor, an impact mechanism, a drive unit, an impact detection unit, and a control unit. The control unit reduces a driving force for the motor caused by the drive unit when a count of impacts detected by the impact detection unit has reached a determination count set in advance, which is a value greater than one.
    Type: Application
    Filed: June 4, 2013
    Publication date: May 28, 2015
    Inventors: Tokuo Hirabayashi, Ryunosuke Kumagai, Takeshi Nishimiya, Goshi Ishikawa, Takuya Kusakawa
  • Publication number: 20150135907
    Abstract: A power tool of one aspect for tightening a screw to a tightening-target-object is provided with a motor as a drive force. A motor controlling device controls the motor so as to make rotational frequency of the motor in accordance with an input operation received by an input-operation receiving unit. A first setting unit sets a maximum rotational frequency to a given first maximum rotational frequency when the motor is initiated. If the power tool clears a given condition for increasing rotational frequency after the motor is initiated, a second setting unit sets the maximum rotational frequency to a given second maximum rotational frequency that is larger than the first maximum rotational frequency.
    Type: Application
    Filed: May 20, 2013
    Publication date: May 21, 2015
    Inventors: Tokuo Hirabayashi, Ryunosuke Kumagai, Takeshi Nishimiya, Goshi Ishikawa, Takuya Kusakawa
  • Patent number: 8981680
    Abstract: An electric power tool of the present invention includes: a lighting unit; a motor that drives a tool element; a setting switch that is turned ON/OFF to change an operation mode setting and a lighting mode setting; a setting switching unit that changes the operation mode setting and the lighting mode setting corresponding to a manner of operation provided to the setting switch; a motor control unit that controls the motor according to a control method for one of the operation modes currently set by the setting switching unit; and a lighting control unit that controls the lighting unit corresponding to one of the lighting modes currently set by the setting switching unit. When the setting switch is turned on, the setting switching unit changes one of the operation mode setting and the lighting mode setting corresponding to a duration time of an ON state of the setting switch.
    Type: Grant
    Filed: September 21, 2012
    Date of Patent: March 17, 2015
    Assignee: Makita Corporation
    Inventors: Hidekazu Suda, Takuya Kusakawa, Jun Ota
  • Publication number: 20150042247
    Abstract: A motor-driven appliance includes a motor and a control unit that controls a drive output to the motor. The control unit detects a state amount indicating an operational state of the motor to derive a fluctuation range of fluctuation in the state amount. The control unit detects whether the motor is in an unloaded state or in a loaded state, based on the derived fluctuation range to perform the drive output to the motor, based on the detected result.
    Type: Application
    Filed: July 24, 2014
    Publication date: February 12, 2015
    Inventor: Takuya KUSAKAWA
  • Publication number: 20150002070
    Abstract: An electric power tool includes a motor with a rotor having a permanent magnet; a control unit that sets a control amount of the motor in accordance with operation of an operation portion and that drive-controls the motor based on the control amount; and a number-of-rotations detection unit that detects the number of rotations of the motor. During driving of the motor, when the number of rotations detected by the number-of-rotations detection unit has reached an upper limit number of rotations set in advance, the control unit shifts drive control of the motor to rotation control, in which the control amount is made to be increased or decreased so that the number of rotations of the motor becomes a predetermined target number of rotations.
    Type: Application
    Filed: June 5, 2014
    Publication date: January 1, 2015
    Inventors: Goshi ISHIKAWA, Takuya KUSAKAWA
  • Patent number: 8890449
    Abstract: A lock state occurrence determination apparatus includes a counter, a reset device, a reference time changing device, a lock state determination device, and an invalidation device. The invalidation device performs, in a case where a false determination of occurrence of a lock state of a motor is caused by the lock state determination device due to an operation input to operate a rotation speed of the motor, at least one of a first invalidation operation to invalidate the lock state determination device and a second invalidation operation to invalidate continuation of a counting operation by the counter.
    Type: Grant
    Filed: May 26, 2011
    Date of Patent: November 18, 2014
    Assignee: Makita Corporation
    Inventors: Jiro Suzuki, Takuya Kusakawa
  • Publication number: 20140334270
    Abstract: A device for a motor-driven appliance includes a communication unit, a date/time information acquisition unit, and a control unit. The communication unit performs communication with an external appliance having a date/time information indicating a current date and time. The date/time information acquisition unit acquires the date/time information from the external appliance via the communication unit. The control unit performs control based on the date/time information acquired by the date/time information acquisition unit.
    Type: Application
    Filed: April 28, 2014
    Publication date: November 13, 2014
    Applicant: MAKITA CORPORATION
    Inventor: Takuya KUSAKAWA
  • Patent number: 8796976
    Abstract: An electric power tool includes a motor that rotary drives an output shaft; an operation unit to input a drive command of the motor; a torque setting device that sets an upper limit value of a rotational torque of the output shaft in accordance with a torque setting command; and a control device that drives the motor in one of a forward direction and a reverse direction in accordance with the drive command, and stops driving of the motor when the rotational torque of the output shaft has reached the upper limit value set by the torque setting device during driving of the motor. The torque setting device is configured to set the upper limit value such that the upper limit value during driving of the motor in the forward direction and the upper limit value during driving of the motor in the reverse direction are different.
    Type: Grant
    Filed: September 27, 2012
    Date of Patent: August 5, 2014
    Assignee: Makita Corporation
    Inventor: Takuya Kusakawa
  • Publication number: 20140125256
    Abstract: A variable speed switch includes a switch main body portion which is accommodated in a housing of an electric power tool and mounted to the housing so as to be capable of relative movement, and a load sensor which is provided in the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force. The switch operating portion is mounted on the surface of the housing so as to be capable of relative displacement with respect to the housing and transmits a pressing force applied to the switch operating portion to the load sensor, with the maximum displacement amount of the switch operating portion being set to equal to or less than 5 mm.
    Type: Application
    Filed: January 10, 2014
    Publication date: May 8, 2014
    Applicant: MAKITA CORPORATION
    Inventors: Masahiro WATANABE, Takuya KUSAKAWA, Hidenori NAGASAKA
  • Patent number: 8698430
    Abstract: A variable speed switch includes a switch main body portion which is accommodated in a housing of an electric power tool and mounted to the housing so as to be capable of relative movement, and a load sensor which is provided in the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force. The switch operating portion is mounted on the surface of the housing so as to be capable of relative displacement with respect to the housing and transmits a pressing force applied to the switch operating portion to the load sensor, with the maximum displacement amount of the switch operating portion being set to equal to or less than 5 mm.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: April 15, 2014
    Assignee: Makita Corporation
    Inventors: Masahiro Watanabe, Takuya Kusakawa, Hidenori Nagasaka
  • Patent number: 8674640
    Abstract: An electric power tool includes: a motor; a manipulation input receiving unit which receives a user manipulation input for rotating the motor; a mode changeover unit that has one manipulation portion which manipulated by the user; a rotation drive force transmitting unit that switches a transmission mechanism to one of the transmission mechanisms corresponding to the set position of the manipulation portion and transmits a drive force of the motor to a tool output shaft via the switched transmission mechanism; an electric signal output unit that outputs an electric signal corresponding to the set position of the manipulation portion; and a motor control unit that sets the control method of the motor to a control method preset for the electric signal, among a plurality of different types of control methods, based on the electric signal, and controls the motor by the set control method, based on manipulation by the user.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: March 18, 2014
    Assignee: Makita Corporation
    Inventors: Hidekazu Suda, Takuya Kusakawa
  • Patent number: 8659244
    Abstract: A variable speed switch includes a switch main body portion which is accommodated in a housing of an electric power tool and mounted to the housing so as to be capable of relative movement, and a load sensor which is provided in the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force. The switch operating portion is mounted on the surface of the housing so as to be capable of relative displacement with respect to the housing and transmits a pressing force applied to the switch operating portion to the load sensor, with the maximum displacement amount of the switch operating portion being set to equal to or less than 5 mm.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: February 25, 2014
    Assignee: Makita Corporation
    Inventors: Masahiro Watanabe, Takuya Kusakawa, Hidenori Nagasaka
  • Patent number: 8616300
    Abstract: A power tool of the present teachings comprises a prime mover that drives a tool, a main switch that causes the prime mover to operate when the main switch is turned on and causes the prime mover to stop operating when the main switch is turned off, an illuminator that lights a working area of the tool, and a lighting mode selector switch for switching the lighting mode of the illuminator between a plurality of lighting modes which include a first lighting mode and a second lighting mode. When the first lighting mode is selected, the illuminator will be turned on for a first predetermined period from the point at which the main switch is turned off. When the second lighting mode is selected, the illuminator will not be turned on during the first predetermined period from the point at which the main switch is turned off.
    Type: Grant
    Filed: June 1, 2009
    Date of Patent: December 31, 2013
    Assignee: Makita Corporation
    Inventors: Jiro Suzuki, Hirokatsu Yamamoto, Takuya Kusakawa
  • Patent number: 8552669
    Abstract: A duty ratio control device includes a duty ratio calculation unit and a parameter setting unit. The duty ratio calculation unit, when an acceleration manipulation is performed, calculates a control duty ratio per predetermined timing based on a value of at least one parameter so that a rotation speed of a motor mounted on an electric power tool reaches a target rotation speed corresponding to the acceleration manipulation. The control duty ratio is calculated to be larger as the value of the at least one parameter is larger. The parameter setting unit sets the value of the at least one parameter. The value of the at least one parameter set for a reacceleration manipulation is larger than the value of the at least one parameter set for an initial acceleration manipulation.
    Type: Grant
    Filed: October 6, 2011
    Date of Patent: October 8, 2013
    Assignee: Makita Corporation
    Inventor: Takuya Kusakawa
  • Publication number: 20130082632
    Abstract: An electric power tool includes a motor that rotary drives an output shaft; an operation unit to input a drive command of the motor; a torque setting device that sets an upper limit value of a rotational torque of the output shaft in accordance with a torque setting command; and a control device that drives the motor in one of a forward direction and a reverse direction in accordance with the drive command, and stops driving of the motor when the rotational torque of the output shaft has reached the upper limit value set by the torque setting device during driving of the motor. The torque setting device is configured to set the upper limit value such that the upper limit value during driving of the motor in the forward direction and the upper limit value during driving of the motor in the reverse direction are different.
    Type: Application
    Filed: September 27, 2012
    Publication date: April 4, 2013
    Inventor: Takuya KUSAKAWA
  • Publication number: 20130082631
    Abstract: A lock state occurrence determination apparatus includes a counter, a reset device, a reference time changing device, a lock state determination device, and an invalidation device. The invalidation device performs, in a case where a false determination of occurrence of a lock state of a motor is caused by the lock state determination device due to an operation input to operate a rotation speed of the motor, at least one of a first invalidation operation to invalidate the lock state determination device and a second invalidation operation to invalidate continuation of a counting operation by the counter.
    Type: Application
    Filed: May 26, 2011
    Publication date: April 4, 2013
    Applicant: MAKITA CORPORATION
    Inventors: Jiro Suzuki, Takuya Kusakawa
  • Publication number: 20130076271
    Abstract: An electric power tool of the present invention includes: a lighting unit; a motor that drives a tool element; a setting switch that is turned ON/OFF to change an operation mode setting and a lighting mode setting; a setting switching unit that changes the operation mode setting and the lighting mode setting corresponding to a manner of operation provided to the setting switch; a motor control unit that controls the motor according to a control method for one of the operation modes currently set by the setting switching unit; and a lighting control unit that controls the lighting unit corresponding to one of the lighting modes currently set by the setting switching unit. When the setting switch is turned on, the setting switching unit changes one of the operation mode setting and the lighting mode setting corresponding to a duration time of an ON state of the setting switch.
    Type: Application
    Filed: September 21, 2012
    Publication date: March 28, 2013
    Applicant: MAKITA CORPORATION
    Inventors: Hidekazu SUDA, Takuya KUSAKAWA, Jun OTA
  • Publication number: 20130068491
    Abstract: An electric power tool includes: a motor; an operation unit; a control parameter setting unit; and a control unit. The control parameter setting unit sets, as a control parameter of the motor, an optimum maximum rotational speed of the motor corresponding to a predetermined set torque or a control amount corresponding to the optimum maximum rotational speed. The control unit is configured to drive the motor in response to an operation amount of the operation unit and to control a rotational speed of the motor at or smaller than the optimum maximum rotational speed based upon the control parameter. The control parameter setting unit determines, as the optimum maximum rotational speed, a rotational speed of the motor that rotates with a rotational energy required to rotate the output shaft at the set torque and sets the optimum maximum rotational speed as the control parameter.
    Type: Application
    Filed: September 17, 2012
    Publication date: March 21, 2013
    Inventors: Takuya KUSAKAWA, Tokuo HIRABAYASHI, Kenji KOBAYASHI