Patents by Inventor Takuhiro Murakami

Takuhiro Murakami 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: 10836019
    Abstract: In order to provide an impact work machine capable of preventing oil leakage and cooling a power transmission apparatus, an impact work machine transmitting power of an electric motor 16 including an output shaft extending in an axis A1 direction to an anvil includes: a housing including a motor case accommodating the electric motor, and a grip extending from the motor case; a speed reducer and an impact mechanism 96 each transmitting power of the electric motor to the anvil; a hammer case located forward of the motor case and nonrotatable relative to the motor case; an extension portion provided on the housing and extending from the motor case toward the hammer case so as to cover at least part of the hammer case; and a passage provided between the hammer case and the extension portion and through which air passes.
    Type: Grant
    Filed: January 8, 2016
    Date of Patent: November 17, 2020
    Assignee: KOKI HOLDINGS CO., LTD.
    Inventors: Akira Matsushita, Takuhiro Murakami, Tomomasa Nishikawa, Junichi Toukairin, Shota Takeuchi
  • Publication number: 20200215679
    Abstract: Provided is an electric device capable of suppressing vibration of a battery pack. Included are: a first housing 21 accommodating a load portion that consumes electric power; a second housing 22 having one end portion connected to the first housing 21 and another end portion to which a battery pack 9 is connectable; and an elastic member 40 interposed between the first housing and the second housing. The first housing includes a first restricting portion 42 positioned away from the elastic member, and the second housing includes a second restricting portion 44 positioned away from the elastic member and engageable with the first restricting portion. In a case where the second housing is urged to be separated from the first housing, the elastic member is deformed and the first restricting portion and the second restricting portion are engaged with each other to prevent separation.
    Type: Application
    Filed: August 31, 2018
    Publication date: July 9, 2020
    Applicant: KOKI HOLDINGS CO., LTD.
    Inventors: Kengo TAMURA, Takuhiro MURAKAMI, Junichi TOUKAIRIN, Yoshihiro KOMURO, Masaru HIRANO
  • Publication number: 20200161609
    Abstract: The electrical apparatus, in which a series connection state and a parallel connection state of an upper cell unit including five battery cells and a lower cell unit can be automatically switched by means of a difference in a terminal shape on the electrical apparatus body side, has a terminal holder and holds apparatus side terminals. The terminal holder, which establishes an electrically connected state with the connection terminals of the battery pack, is provided with two parallel protruding parts that extend in the forward-backward direction, and second rail grooves fitted to the protruding parts on the electrical apparatus side. Due to the fitting, relative movement of the terminal holder and the battery pack in the vertical direction can be suppressed, and wear on the apparatus side terminals can be greatly suppressed.
    Type: Application
    Filed: June 29, 2018
    Publication date: May 21, 2020
    Applicant: Koki Holdings Co., Ltd.
    Inventors: Takuhiro Murakami, Tomomasa NISHIKAWA, Shinji Watanabe, Junpei SATO, Hikaru Tamura, Shota KANNO, Toshio Mizoguchi, Yasushi Nakano, Hiroyuki HANAWA, Kazuhiko FUNABASHI, Masayuki Ogura, Takuya Teranishi, Junichi Toukairin, Shota Takeuchi, Yusuke FUNABIKI
  • Patent number: 10654153
    Abstract: In order to provide an impact tool which is capable of increasing a striking force in a rotational direction of being applied from a hammer to an anvil, the impact tool includes: an electric motor; an anvil which supports a work tool and is driven by the electric motor; and a hammer which applies the striking force in the rotational direction to the anvil. The impact tool is provided with: a spindle which is arranged to be concentric with the anvil, supports the hammer to be movable in an axial direction and the rotational direction with respect to the anvil, and transmits motive power of the electric motor to the anvil; and a control unit which controls rotation speed of the electric motor. The number of strokes of the anvil due to one rotation of the hammer differs in response to rotation speed of the electric motor.
    Type: Grant
    Filed: January 8, 2016
    Date of Patent: May 19, 2020
    Assignee: KOKI HOLDINGS CO., LTD.
    Inventors: Takuhiro Murakami, Junichi Toukairin, Shota Takeuchi, Hironori Mashiko, Yuta Noguchi
  • Publication number: 20190259984
    Abstract: A battery pack houses first and second cell units that are composed of a plurality of cells, and has a positive electrode power source terminal and a negative electrode power source terminal. This battery pack is provided with a series connector capable of connecting, in series, the first and second cell units and a parallel connector capable of connecting, in parallel, the first and second cell units, and is capable of switching between a parallel connection voltage and a series connection voltage. In the case of attachment to the high voltage electrical device body, the series connector becomes conductive and the parallel connector pair is cut off by the action of the series/parallel switching terminal. In the case of attachment to a low voltage electrical device body, the state is returned to an initial state, the series connector is cut off, and the parallel connector pair becomes conductive.
    Type: Application
    Filed: October 27, 2017
    Publication date: August 22, 2019
    Applicant: Koki Holdings Co., Ltd.
    Inventors: Tomomasa NISHIKAWA, Takuya Teranishi, Naoto Wakatabe, Akira Matsushita, Masaru Hirano, Osamu Kawanobe, Nobuhiro TAKANO, Shinji Watanabe, Hiroyuki HANAWA, Takuhiro Murakami, SHOTA KANNO, Junpei Sato, Hikaru Tamura, Hayato Yamaguchi, Toshio Mizoguchi, Yasushi Nakano, Kazuhiko FUNABASHI, Masayuki Ogura, Yusuke FUNABIKI, Junichi Toukairin, Shota Takeuchi
  • Publication number: 20190260209
    Abstract: In order that the output voltage of a battery pack can be switched and the battery pack can be shared among different voltage electric appliances, this battery pack has a switching mechanism that switches outputting a low voltage by parallel connection of two cell units or outputting a high voltage by series connection of the two cell units, said two cell units each being composed of a plurality of cells connected in series, wherein the switching mechanism is configured from a change-over switch having an operation lever (452). The change-over switch is embedded in a battery pack (400), and an operator is able to manually switch outputting 18 V by setting the operation lever (452) at a first position or outputting 36 V by setting the operation lever (452) at a second position.
    Type: Application
    Filed: October 27, 2017
    Publication date: August 22, 2019
    Applicant: Koki Holdings Co., Ltd.
    Inventors: Tomomasa NISHIKAWA, Masayuki OGURA, Masaru HIRANO, Takuhiro MURAKAMI, Nobuhiro TAKANO, Osamu KAWANOBE, Akira MATSUSHITA, Hayato YAMAGUCHI
  • Publication number: 20190259985
    Abstract: In an upper cell unit (2146) and a lower cell unit (2147) comprising five battery cells, positive electrode terminals (2162, 2172) are set apart and aligned vertically, and negative electrode terminals (2167, 2177) are set apart and aligned vertically. When an electrical device body is rated at 36V, device-side terminals are in contact only at the upper terminals (2162, 2167), and short circuiting of the lower terminals (2172, 2177) is effected using a short bar 2059. When the electrical device body is rated at 18V, the upper and lower terminals (2162 and 2172, 2167 and 2177) are simultaneously made to contact the device-side terminals, and the upper cell unit (2146) and the lower cell unit (2147) assume a parallel connected state. Thus, it is possible to automatically switch the output voltage when a battery pack is mounted according to the difference in terminal shape on the electrical device body side.
    Type: Application
    Filed: October 27, 2017
    Publication date: August 22, 2019
    Applicant: Koki Holdings Co., Ltd.
    Inventors: Hiroyuki HANAWA, Tomomasa NISHIKAWA, SHOTA KANNO, Toshio Mizoguchi, Yasushi Nakano, Kazuhiko FUNABASHI, Takuya Teranishi, Naoto Wakatabe, Shinji Watanabe, Junpei Sato, Hikaru Tamura, Nobuhiro TAKANO, Osamu Kawanobe, Hayato Yamaguchi, Akira Matsushita, Masaru Hirano, Takuhiro Murakami, Masayuki Ogura, Yusuke Funabiki, Junichi Toukairin, Shota Takeuchi
  • Publication number: 20190193174
    Abstract: A cutting tool capable of positioning a third pulley with high accuracy is provided. A miter saw includes a first pulley rotatable integrally with a motor shaft, a countershaft at which a second pulley and a third pulley are provided, a first belt looped under tension over the first pulley and the second pulley, an output shaft at which a fourth pulley is provided, a second belt looped under tension over the third pulley and the fourth pulley, a bearing which rotatably supports the countershaft and is positioned between the second pulley and the third pulley, a bearing which rotatably supports the countershaft and is positioned opposite to the second pulley relative to the third pulley, a gear case supporting the bearing, and a gear cover supporting the bearing. The gear case has a portion positioned between the second pulley and the third pulley.
    Type: Application
    Filed: August 25, 2017
    Publication date: June 27, 2019
    Inventors: Takuhiro MURAKAMI, Masaru HIRANO, Yoshitaka SEKINE, Satoshi IWATA
  • Publication number: 20180117745
    Abstract: In order to provide an impact tool which is capable of increasing a striking force in a rotational direction of being applied from a hammer to an anvil, the impact tool includes: an electric motor; an anvil which supports a work tool and is driven by the electric motor; and a hammer which applies the striking force in the rotational direction to the anvil. The impact tool is provided with: a spindle which is arranged to be concentric with the anvil, supports the hammer to be movable in an axial direction and the rotational direction with respect to the anvil, and transmits motive power of the electric motor to the anvil; and a control unit which controls rotation speed of the electric motor. The number of strokes of the anvil due to one rotation of the hammer differs in response to rotation speed of the electric motor.
    Type: Application
    Filed: January 8, 2016
    Publication date: May 3, 2018
    Inventors: Takuhiro MURAKAMI, Junichi TOUKAIRIN, Shota TAKEUCHI, Hironori MASHIKO, Yuta NOGUCHI
  • Publication number: 20180001444
    Abstract: In order to provide an impact work machine capable of preventing oil leakage and cooling a power transmission apparatus, an impact work machine transmitting power of an electric motor 16 including an output shaft extending in an axis A1 direction to an anvil includes: a housing including a motor case accommodating the electric motor, and a grip extending from the motor case; a speed reducer and an impact mechanism 96 each transmitting power of the electric motor to the anvil; a hammer case located forward of the motor case and nonrotatable relative to the motor case; an extension portion provided on the housing and extending from the motor case toward the hammer case so as to cover at least part of the hammer case; and a passage provided between the hammer case and the extension portion and through which air passes.
    Type: Application
    Filed: January 8, 2016
    Publication date: January 4, 2018
    Inventors: Akira MATSUSHITA, Takuhiro MURAKAMI, Tomomasa NISHIKAWA, Junichi TOUKAIRIN, Shota TAKEUCHI
  • Publication number: 20170036327
    Abstract: Provided is an impact type electric tool. A striking mechanism is used, which uses a hammer having striking claws that are equally arranged in the rotational direction and an anvil having struck claws. A relationship between a striking energy E, which the hammer has right before striking the anvil, and a disengaging torque TB, which is applied between the hammer and the anvil right before the hammer is disengaged from the anvil, is set as 5.3×TB<E<9.3×TB in the case of three claws and set as 9.3×TB<E<15.0×TB in the case of two claws, so as to perform striking by skipping one of the claws of the hammer and the anvil when a high torque is required. Accordingly, the electric tool achieves output of a high torque while maintaining a favorable operational feeling during striking.
    Type: Application
    Filed: August 1, 2016
    Publication date: February 9, 2017
    Applicant: Hitachi Koki Co., Ltd.
    Inventors: Takuhiro Murakami, Junichi Tokairin, Shota Takeuchi, Hironori Mashiko, Yuta Noguchi, Akira Matsushita
  • Publication number: 20160273467
    Abstract: A cost of an engine working machine is suppressed, and startability of an engine is improved. In an engine working machine for driving a working tool by using an engine including: a fuel tank; a carburetor for supplying air-fuel mixture of fuel supplied from the fuel tank and air into a cylinder; a cylinder in which a piston is reciprocatable; and a crank case that holds the cylinder and forms a crank chamber, the engine working machine is provided with: an additional fuel supplying unit for supplying fuel to the engine separately from the carburetor; and a control unit for controlling an operation of the additional fuel supplying unit separately from supply of start-up fuel.
    Type: Application
    Filed: November 13, 2013
    Publication date: September 22, 2016
    Inventors: Yoshikazu KAWANO, Junichi KAMIMURA, Takuhiro MURAKAMI
  • Patent number: 9345156
    Abstract: A power supply device includes a main body, a cover member, a rechargeable battery, and an inverter device. The main body is configured of box-shape formed with an opening. The cover member is configured to open and close the opening. The rechargeable battery is accommodated in the main body. The inverter device is configured to be accommodated in the main body. The inverter device converts a direct voltage from the battery to an alternating voltage and outputs the alternating voltage.
    Type: Grant
    Filed: August 17, 2012
    Date of Patent: May 17, 2016
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Masayuki Ogura, Shinji Watanabe, Haruhisa Fujisawa, Kazuhiko Funabashi, Takuhiro Murakami, Yasushi Nakano, Hideki Watanabe, Norihide Tao, Takafumi Itoh
  • Publication number: 20140366830
    Abstract: An engine-powered tool 1 includes a starter motor 106 to be driven by electric power supplied from a battery 80 to start an engine, start control means 102 to be driven by electric power from the battery 80 to control rotation of the starter motor 106, and a switching element (FET) 121 provided in series to a power supply circuit from the battery 80 to the starter motor 106, opening and closing of the switching element being controlled by the start control means. When starting the starter motor 106, PWM control is performed on the switching element and soft start in which a duty ratio is gradually increased is performed. The start control means 102 monitors temperature and battery voltage, and changes a ratio and time for increasing the duty ratio in the PWM control in accordance with the temperature and the voltage.
    Type: Application
    Filed: January 23, 2013
    Publication date: December 18, 2014
    Inventors: Yoshikazu Kawano, Takuhiro Murakami
  • Patent number: 8876578
    Abstract: A portable working machine is provided with a wheel guard partially covering a wheel rotated by a drive source such as an engine, and the wheel guard is retained by a retaining portion of an arm via rubber dampers serving as elastic members. Concave-convex portions are formed on the rubber dampers, a convex-concave portion corresponding to the concave-convex portions is formed in the wheel guard side, and the wheel guard is retained by the arm so that the concave-convex portions are engaged with the convex-concave portion.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: November 4, 2014
    Assignee: Hitachi Koki Co., Ltd.
    Inventor: Takuhiro Murakami
  • Publication number: 20140153171
    Abstract: A power supply device includes a main body, a cover member, a rechargeable battery, and an inverter device. The main body is configured of box-shape formed with an opening. The cover member is configured to open and close the opening. The rechargeable battery is accommodated in the main body. The inverter device is configured to be accommodated in the main body. The inverter device converts a direct voltage from the battery to an alternating voltage and outputs the alternating voltage.
    Type: Application
    Filed: August 17, 2012
    Publication date: June 5, 2014
    Applicant: Hitachi Koki Co., Ltd.
    Inventors: Masayuki Ogura, Shinji Watanabe, Haruhisa Fujisawa, Kazuhiko Funabashi, Takuhiro Murakami, Yasushi Nakano, Hideki Watanabe, Norihide Tao, Takafumi Itoh
  • Publication number: 20130160740
    Abstract: An engine including: a cylinder block formed with a cylinder bore; a carburetor including, a fuel storage portion that stores fuel supplied from a fuel tank and supplies the fuel to a suction path, and a fuel discharge path that discharges fuel overflowed from the fuel storage portion; a starting fuel supply device including, a starting fuel storage chamber that is provided on a fuel route defined by the fuel tank and the carburetor and stores a predetermined amount of fuel, a fuel delivery portion that delivers the fuel to a starting fuel supply path connected to the suction path or the cylinder bore, and a fuel return path that discharges the fuel overflowed from the starting fuel storage chamber; and a notifying portion that visually notifies that the starting fuel storage chamber is filled with fuel.
    Type: Application
    Filed: April 28, 2011
    Publication date: June 27, 2013
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Junichi Kamimura, Takuhiro Murakami, Naoto Ichihashi, Kentarou Kanaya
  • Publication number: 20120276823
    Abstract: A portable working machine is provided with a wheel guard partially covering a wheel rotated by a drive source such as an engine, and the wheel guard is retained by a retaining portion of an arm via rubber dampers serving as elastic members. Concave-convex portions are formed on the rubber dampers, a convex-concave portion corresponding to the concave-convex portions is formed in the wheel guard side, and the wheel guard is retained by the arm so that the concave-convex portions are engaged with the convex-concave portion.
    Type: Application
    Filed: April 27, 2012
    Publication date: November 1, 2012
    Inventor: Takuhiro MURAKAMI
  • Patent number: D622660
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: August 31, 2010
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Takeshi Taniguchi, Masanori Okada, Takuhiro Murakami
  • Patent number: D668608
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: October 9, 2012
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Takafumi Itoh, Masanori Okada, Hiroyuki Hasegawa, Masayuki Ogura, Takuhiro Murakami