Patents by Inventor Tomomasa Nishikawa

Tomomasa Nishikawa 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: 20130126202
    Abstract: An screw tightening tool (1) includes: a handle part (22) to be held by a user; a trigger (25); a power supplying section (6, 7) that supplies an electrical power in accordance with an operated amount of the trigger; and a motor (3) that rotates in accordance with the electrical power supplied from the power supplying section. The power supplying section supplies the motor with a preventing electrical power for preventing the motor from rotating with respect to the handle part when a predetermined condition is satisfied.
    Type: Application
    Filed: August 1, 2011
    Publication date: May 23, 2013
    Applicant: Hitachi Koki Co., Ltd.
    Inventors: Katsuhiro Oomori, Mizuho Nakamura, Yutaka Ito, Tomomasa Nishikawa, Hironori Mashiko, Atsushi Sumi, Takeshi takeda, Masayuki Ogura
  • Publication number: 20130087355
    Abstract: An impact tool (1) includes a motor (3); a hammer (42) having a rotational axis extending in a first direction, the hammer (42) being rotatable in a rotational direction including a forward direction and a reverse direction opposite to the forward direction by the motor (3) and being movable in the first direction and a second direction opposite to the first direction; an anvil (52) disposed at the first direction side of the hammer (42) and strikable by the hammer (42) in the forward direction, the hammer (42) that has been struck the anvil (52) being moved in the second direction to come free from the anvil (52); and a fixing member (45A, 46A) that selectively allows the hammer (42) to move in the second direction or prevents the hammer (42) from moving in the second direction.
    Type: Application
    Filed: June 30, 2011
    Publication date: April 11, 2013
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Katsuhiro Oomori, Mizuho Nakamura, Yutaka Ito, Nobuhiro Takano, Tomomasa Nishikawa, Hironori Mashiko, Shigeru Takahashi
  • Publication number: 20130062088
    Abstract: An impact tool including: a motor; a speed-reduction mechanism that reduces a torque of the motor; a hammer connected to an output portion of the speed-reduction mechanism; and an anvil that can be swung relatively to the hammer, wherein the hammer is directly driven by the motor, and wherein the impact tool can operate in: a drill mode in which an end tool attached to the anvil is rotated by rotating the hammer in one direction so as to rotate the anvil; and an impact mode in which the end tool attached to the anvil is rotated while the hammer intermittently strikes the anvil.
    Type: Application
    Filed: February 21, 2011
    Publication date: March 14, 2013
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Hironori Mashiko, Tomomasa Nishikawa, Hayato Yamaguchi
  • Publication number: 20130062086
    Abstract: The present invention provides a power tool for tightening a fastener. The power tool includes a motor, a hammer, an anvil, and a control unit. The hammer is intermittently or continuously rotatable in a forward direction by the motor. The anvil is impacted by the hammer rotated in the forward direction. The control unit controls the hammer to continuously rotate at a first number of rotations, and to intermittently rotate at a second number of rotations lower than the first number of rotations when a prescribed time has elapsed from the rotation of the hammer at the first number of rotations, and then to intermittently rotate at a third number of rotations lower than the second number of rotations when a predetermined time has elapsed from the rotation of the hammer at the second number of rotations.
    Type: Application
    Filed: April 12, 2011
    Publication date: March 14, 2013
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Yutaka Ito, Katsuhiro Oomori, Mizuho Nakamura, Tomomasa Nishikawa, Hironori Mashiko
  • Patent number: 8371034
    Abstract: A dust collection cover capable of efficiently collecting cutting chips and residues generated as a result of cutting a workpiece. A cutter includes a motor and a rotary blade driven by the motor, and the dust collection cover is attached to the cover for covering a part of the blade. The cover is formed with a dust discharge port through which cutting chips and residues are discharged. The cover has a guide arrangement for directing the cutting chips and residues toward an interior of the cover body. The arrangement provides a blowing-out air blowing to the workpiece, or a rod-like member removing the cutting chips and residues.
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: February 12, 2013
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Tomomasa Nishikawa, Shinki Ohtsu
  • Publication number: 20130025892
    Abstract: An electronic pulse driver includes a motor, a hammer, an anvil, an end tool mounting unit, a power supply unit, a temperature detecting unit, and a controller. The hammer is drivingly rotatable in forward and reverse directions by the motor. The anvil is provided separately from the hammer and rotated upon striking of the hammer. The power supply unit alternately supplies a forward electric power and a reverse electric power to the motor in a first cycle. The temperature detecting unit is configured to detect a temperature of the motor. The controller is configured to control the power supply unit to alternately supplies the forward electric power and the reverse electric power in a second cycle longer than the first cycle when the temperature of the motor detected by the temperature detecting unit increases to a prescribed value.
    Type: Application
    Filed: March 11, 2011
    Publication date: January 31, 2013
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Hironori Mashiko, Nobuhiro Takano, Kazutaka Iwata, Tomomasa Nishikawa, Katsuhiro Oomori, Mizuho Nakamura, Yutaka Ito
  • Publication number: 20130014967
    Abstract: An electronic pulse driver includes a motor, a hammer, an anvil, an end tool mounting unit, a power supply unit, and a control unit. The hammer is rotatable together with the anvil. The end tool mounting unit transmits the rotation of the anvil to an end tool. The power supply unit supplies a drive electric power to the motor. The control unit controls the power supply unit to halt a supply of the drive electric power to the motor when an electric current flowing to the motor increases to a prescribed value. The control unit controls the power supply unit to supply to the motor a prestart electric power lower than the drive electric power before supplying the drive electric power in order to permit the power supply unit to supply the drive electric power after the hammer is in contact with the anvil.
    Type: Application
    Filed: March 29, 2011
    Publication date: January 17, 2013
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Yutaka Ito, Katsuhiro Oomori, Mizuho Nakamura, Tomomasa Nishikawa, Hironori Mashiko
  • Publication number: 20130008679
    Abstract: An electronic pulse driver includes a motor, a hammer, an anvil, an end tool mounting unit, a power supply unit, and a control unit. The hammer is rotationally driven in forward and reverse directions by the motor. The anvil is rotated upon striking the hammer against the anvil as a result of a rotation of the hammer in the forward direction after rotation of the hammer in the reverse direction for obtaining a distance for acceleration in the forward direction. The power supply unit alternately supplies to the motor a forward electric power and a reverse electric power in a first cycle. The control unit controls the power supply unit to alternately supplies the forward electric power and the reverse electric power in a second cycle shorter than the first cycle when an electric current flowing to the motor increases to a prescribed value.
    Type: Application
    Filed: March 11, 2011
    Publication date: January 10, 2013
    Applicant: Hitachi Koki Co., Ltd.
    Inventors: Tomomasa Nishikawa, Nobuhiro Takano, Kazutaka Iwata, Hironori Mashiko, Katsuhiro Oomori, Mizuho Nakamura, Yutaka Ito
  • Patent number: 8342782
    Abstract: According to the invention, a drilling tool includes: a driving source; a transmission drive unit for transmitting a rotation force of the driving source; and a dust collector for collecting dust produced from a workpiece drilled by the end tool and blowing air against the workpiece, wherein a filtering means for filtering the air mixed with the collected dust and a centrifugal fan for taking in the filtered air and sending out the filtered air in a circumferential direction are provided, the centrifugal fan is disposed in a housing formed with an airflow sending port for sending a part of the air taken in to the dust collector and a discharge port for discharging a rest of the air to an outside, and a distance from the airflow sending port to the discharge port in a forward direction in a direction of rotation of the centrifugal fan is longer than the distance from the airflow sending port to the discharge port.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: January 1, 2013
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Tomomasa Nishikawa, Kenji Kobori, Shingo Yamazaki
  • Patent number: 8338997
    Abstract: According to an aspect of the present invention, there is provided a power tool including: a motor that generates a rotational force; a power transmission mechanism that is driven by the motor to transmit the rotational force and that is connected to a bit; and a housing that houses the motor and the power transmission mechanism therein, wherein an electric fan for cooling the power transmission mechanism or the motor is provided inside the housing, wherein the power transmission mechanism, the motor and the electric fan are arranged in this order from front, and wherein the electric fan is disposed at a rear side so as to be interposed between the motor and a back wall of the housing.
    Type: Grant
    Filed: November 18, 2009
    Date of Patent: December 25, 2012
    Assignee: Hitachi Koki Co., Ltd.
    Inventor: Tomomasa Nishikawa
  • Publication number: 20120318550
    Abstract: An impact tool including: a motor; a hammer connected to the motor; and an anvil struck by the hammer by driving the motor alternately in a normal rotation and a reverse rotation, wherein a magnitude of a fastening torque by the anvil is calculated in accordance with a current value of a current supplied to the motor immediately after the striking.
    Type: Application
    Filed: March 11, 2011
    Publication date: December 20, 2012
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Hideyuki Tanimoto, Nobuhiro Takano, Tomomasa Nishikawa, Kazutaka Iwata, Hironori Mashiko, Hayato Yamaguchi
  • Publication number: 20120292070
    Abstract: An electric tool including: a motor configured to drive a front end tool; a control device configure to control rotation of the motor; a storage part configured to store a method of driving the motor by the control device; and a communication terminal to which a communication line for reading or writing information of the storage part is configured to be connected.
    Type: Application
    Filed: May 18, 2012
    Publication date: November 22, 2012
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Tatsuya ITO, Tomomasa NISHIKAWA, Hironori MASHIKO, Mizuho NAKAMURA, Yoshio IIMURA
  • Publication number: 20120279736
    Abstract: According to an aspect of the present invention, there is provided an impact tool including: a motor drivable in an intermittent driving mode; a hammer connected to the motor; an anvil to be struck by the hammer to thereby rotate/strike a tip tool; and a control unit that controls a rotation of the motor by switching a driving pulse supplied to the motor in accordance with a load applied onto the tip tool.
    Type: Application
    Filed: July 29, 2010
    Publication date: November 8, 2012
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Hideyuki Tanimoto, Nobuhiro Takano, Tomomasa Nishikawa, Kazutaka Iwata, Hironori Mashiko, Hayato Yamaguchi, Atsushi Nakagawa, Katsuhiro Oomori, Mizuho Nakamura, Hiroki Uchida, Saroma Nakano, Yutaka Ito
  • Publication number: 20120234566
    Abstract: An impact tool including: a motor including, a rotor, a stator, and a detecting device that detects a rotation position of the rotor; a hammer driven by the motor so as to be rotated; an anvil configured to rotate relatively to the hammer and is struck by the hammer; and an output shaft connected to the anvil; wherein the anvil is struck by the hammer by rotating the hammer in a forward rotation direction by a second predetermined amount after rotating the hammer in a reverse rotation direction by a first predetermined amount, and wherein the first predetermined amount and the second predetermined amount are controlled based on a rotation angle that is obtained based on an output of the detecting device.
    Type: Application
    Filed: November 30, 2011
    Publication date: September 20, 2012
    Applicant: HITACHI KOKI CO., LTD.,
    Inventors: Hironori MASHIKO, Tomomasa NISHIKAWA, Nobuhiro TAKANO
  • Publication number: 20120199372
    Abstract: According to an aspect of the present invention, there is provided an impact tool including: a motor; a hammer connected to an output portion of the motor; and an anvil to be struck by the hammer in a rotation direction and having a rotary shaft, the hammer striking the anvil in the rotation direction by driving the motor in pulses, wherein the anvil is provided in front of the hammer, wherein the hammer is driven in pulses by the motor, and wherein a rotation angle of the hammer is substantially proportional to a rotation angle of the motor.
    Type: Application
    Filed: July 29, 2010
    Publication date: August 9, 2012
    Applicant: HITACHI KOKI CO., LTD.,
    Inventors: Tomomasa Nishikawa, Nobuhiro Takano, Hideyuki Tanimoto, Kazutaka Iwata, Hironori Mashiko, Hayato Yamaguchi, Atsushi Nakagawa, Katsuhiro Oomori, Mizuho Nakamura, Hiroki Uchida, Saroma Nakano, Chikai Yoshimizu
  • Publication number: 20120184192
    Abstract: To a power tool main body to which a main body spindle rotationally driving a tip tool is provided, a dust collection adapter for collecting dusts generated when a material to be ground is processed by the tip tool is held thereto. The dust collection adapter includes: a dust collection fan rotationally driven by the main body spindle; and a dust collection cover for containing the dust collection fan and covering a diametrical outside of the tip tool. The dust collection fan includes: a fan main body to which a plurality of blade portions are provided; and a threaded shaft portion provided to a center portion of the fan main body. To the threaded shaft portion, a female thread portion thread-coupled to the main body spindle and a male thread portion thread-coupled to a fastening thread member for fixing the tip tool are provided.
    Type: Application
    Filed: January 19, 2012
    Publication date: July 19, 2012
    Inventors: Takashi KAWAMATA, Hiroaki Yonekawa, Tomomasa Nishikawa, Noriyuki Horie, Hiroto Inagawa, Kenichi Katou
  • Patent number: 8205777
    Abstract: A fuel gas has a gas including at least 40 weight % or more of 1-butene and propane, or at least 56 weight % or more of 1-butene and propylene. A combustion type power tool is driven by the fuel gas. A compressed gas container for a combustion type power tool has an inner side vessel filled with the fuel gas. When the fuel gas includes propane, 1-butene may be equal to or higher than 59 weight % and equal to or lower than 95 weight %. When the fuel gas includes propylene, the 1-butene may be equal to or higher than 70 weight % and equal to or lower than 96 weight %.
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: June 26, 2012
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Tomomasa Nishikawa, Shinki Ohtsu, Yasuki Ohmori, Kunio Yamamoto
  • Publication number: 20120073256
    Abstract: A lawn mower comprising: a power supply; a chassis for holding the power supply; a fixed shaft attached to the chassis; a rotary blade which is rotatably supported with respect to the fixed shaft; a transmitting portion which transmits rotation of the power supply to the rotary blade; and a fixed blade which is coaxially-arranged with the rotary blade, wherein a distance between the rotary blade and the fixed blade can be varied.
    Type: Application
    Filed: September 15, 2011
    Publication date: March 29, 2012
    Inventors: Kenji Kobori, Hiroto Inagawa, Tomomasa Nishikawa
  • Publication number: 20110253402
    Abstract: A compact battery pack with high handling ability and restraining degradation of battery cells. The battery pack includes an insertion portion to be inserted into a handle portion of a cordless power tool and an accommodation portion in which all battery cells are accommodatable. A protection board with a protection circuit that protects batteries against overcharge and over-discharge is installed in the insertion portion. A switching element is connected between the battery cells and a drive motor of the power tool. An air passage in communication with the battery pack is formed within the handle and a main housing of the cordless power tool. The switching element is positioned at the air passage.
    Type: Application
    Filed: June 27, 2011
    Publication date: October 20, 2011
    Inventors: Takao ARADACHI, Nobuhiro TAKANO, Tomomasa NISHIKAWA, Hiroyuki HANAWA, Masayuki OGURA, Kazuhiko FUNABASHI
  • Publication number: 20110227430
    Abstract: According to an aspect of the present invention, there is provided a power tool including: a brushless motor; switching elements that drive the brushless motor; a circuit board on which the switching elements are mounted; a transmission portion that transmits a driving force of the brushless motor; and a housing that houses the brushless motor, the switching elements, the circuit board and the transmission portion therein, wherein the switching elements include semiconductor elements each having terminals on a bottom surface thereof, and wherein the switching elements are surface mounted on the circuit board.
    Type: Application
    Filed: May 20, 2009
    Publication date: September 22, 2011
    Applicant: Hitachi Koki Co., Ltd.
    Inventors: Katsuhiro Omori, Junichi Toukairin, Nobuhiro Takano, Kazitala Iwata, Tomomasa Nishikawa