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).

  • Patent number: 10377022
    Abstract: A power tool which has an anvil 20 that is rotated by a hammer 22 and is housed in a housing, and rotates an output shaft 18 is provided. The anvil 20 and the output shaft 18 are integrally formed into one unit, and a carrier 33 that is rotatable relative to the anvil 20 by a predetermined angle on the same axis is provided. On one portion of an outer circumferential surface of the anvil 20, a relief surface 20a is formed. Cut-out portions 33b are formed at positions opposed to each other of a carrier 33, and by allowing an engaging pin 37 to be interposed therein, a locking mechanism that limits the relative rotation between the anvil 20 and a lock ring 38 is prepared. When the tool main body is manually rotated while the hammer 22 is being stopped, the engaging pin 37 limits the relative rotation between the anvil 20 and the lock ring 38. The locked state between the anvil 20 and the lock ring 38 is released immediately when the rotation of the motor 4 is started.
    Type: Grant
    Filed: April 23, 2013
    Date of Patent: August 13, 2019
    Assignee: KOKI HOLDINGS CO., LTD.
    Inventors: Keita Saitou, Shinichirou Satou, Tomomasa Nishikawa, Masanori Watanabe, Takuya Teranishi
  • Publication number: 20190244509
    Abstract: A technique capable of immediately reporting to an operator an occurrence of abnormality in an electric tool is provided. A communication terminal includes a communication-terminal-side control unit that determines whether abnormality has occurred in any of electric tools based on information acquired from the electric tools via wireless communication. When the communication-terminal-side control unit determines the occurrence of abnormality in any one of the electric tools, the occurrence of abnormality in the electric tool is reported by at least one of a report unit included in the electric tools other than the electric tool in which the occurrence of abnormality is determined and a report unit included in the communication terminal.
    Type: Application
    Filed: April 15, 2019
    Publication date: August 8, 2019
    Inventors: Tomomasa NISHIKAWA, Takuya KONNAI, Tatsuya ITO
  • Patent number: 10325475
    Abstract: A technique capable of immediately reporting to an operator an occurrence of abnormality in an electric tool is provided. A communication terminal 100 includes a communication-terminal-side control unit that determines whether abnormality has occurred in any of electric tools 10, 200, 300, and 400 based on information acquired from the electric tools 10, 200, 300, and 400 via wireless communication. When the communication-terminal-side control unit determines the occurrence of abnormality in any one of the electric tools 10, 200, 300, and 400, the occurrence of abnormality in the electric tool 10, 200, 300, or 400 is reported by at least one of a report unit included in the electric tools 10, 200, 300, and 400 other than the electric tool 10, 200, 300, or 400 in which the occurrence of abnormality is determined and a report unit included in the communication terminal 100.
    Type: Grant
    Filed: March 13, 2018
    Date of Patent: June 18, 2019
    Assignee: KOKI HOLDINGS CO., LTD.
    Inventors: Tomomasa Nishikawa, Takuya Konnai, Tatsuya Ito
  • Publication number: 20190148687
    Abstract: The purpose of the invention is to provide a battery pack and a power tool on which the same can be detachably mounted such that compatibility can be ensured even if the dimensions of the battery cells therefor are changed, as well as a battery pack and power tool set. A second battery pack is provided with second battery cells, a second case which houses the second battery cells, a second latch portion for mounting the second battery pack to the power tool, and a second latch operating portion. The second battery pack has a larger case width than that of a specified battery pack for housing battery cells shorter than the second battery cells. However, as the rail width is the same, the second battery pack can be detachably mounted to the power tool in place of the specified battery pack.
    Type: Application
    Filed: March 31, 2017
    Publication date: May 16, 2019
    Applicant: Koki Holdings Co., Ltd.
    Inventors: Tomomasa NISHIKAWA, Satoru MATSUNO, Mitsutaka SAKAMOTO
  • Patent number: 10286462
    Abstract: To provide a cutting machine that suppresses swinging of the cutting portion when the battery pack is attached or detached, the cutting machine includes a cutting portion, a base, and a swing support mechanism. The cutting portion includes: a motor, a motor housing accommodating the motor, an output shaft configured to be rotated upon rotation of the motor, a battery pack serving as a power source of the motor, and a battery pack attaching portion including a pair of rail portions with which the battery pack is engageable, where a cutting blade is configured to be detachably attached to the output shaft. The base has a contact surface on which a workpiece is configured to be placed. The swing support mechanism is connected to the base and the cutting portion and includes a swing shaft extending in parallel to the output shaft.
    Type: Grant
    Filed: April 29, 2016
    Date of Patent: May 14, 2019
    Assignee: Koki Holdings Co., Ltd.
    Inventor: Tomomasa Nishikawa
  • Patent number: 10263228
    Abstract: The sealing property obtained when a battery pack is attached to an electric power tool is improved. An electric power tool to/from which a battery pack retaining a battery cell is attachable/detachable has: a tool main body being provided with an attachment part to/from which the battery pack is attached/detached; a guide groove which is provided in the attachment part and which determines a direction of the attachment/detachment of the battery pack; a device-side terminal which is provided in the attachment part and which is connected to a battery-side terminal provided in the battery pack; and a seal member which is provided in the attachment part and which seals a connecting part between the battery-side terminal and the device-side terminal.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: April 16, 2019
    Assignee: Koki Holdings Co., Ltd.
    Inventors: Tomomasa Nishikawa, Tetsuhiro Harada, Chikai Yoshimizu, Hiroyuki Hanawa
  • Publication number: 20190039228
    Abstract: A power tool has a fan guide for straightening the flow of cooling air generated by a fan, wherein the branching passages through are provided for causing a portion of the cooling air drawn into the fan from a ventilation hole to diverge from a flow toward an exhaust port formed on a bearing guide side, and the portion of the cooling air flows toward an inlet and thereby circulates inside a housing. The branching passages through provided to the fan guide are formed so as to be inclined in the same direction as a circumferential direction so that air path resistance during actual operation (in an intermediate-speed region) does not increase.
    Type: Application
    Filed: January 27, 2017
    Publication date: February 7, 2019
    Applicant: Koki Holdings Co., Ltd.
    Inventors: Akira MATSUSHITA, Tomomasa NISHIKAWA, Noriyuki HORIE, Masahiro FUJIWARA
  • Publication number: 20190030692
    Abstract: To provide a rotary impact tool capable of: suppressing a rise in temperature in a motor or switching elements and a current flowing in the motor or switching elements while suppressing a degradation in tightening performance; and improving operability. The rotary impact tool includes: a motor; an end-bit holding part driven by the motor; an impact mechanism provided on a drive transmission path from the motor to the end-bit holding part and configured to intermittently produce rotary impacts, the rotary impacts transmitting a drive force of the motor to the end-bit holding part; a switching element configured to change a voltage supplied to the motor; and a control unit controlling the switching element. The control unit is configured such that the voltage supplied to the motor begins to gradually rise within a period of time from a timing when a first rotary impact ends to a timing when a second rotary impact subsequent to the first rotary impact starts.
    Type: Application
    Filed: January 6, 2017
    Publication date: January 31, 2019
    Inventors: Tetsuhiro Harada, Tomomasa Nishikawa, Tatsuya Ito, Takahiro Hirai, Yang Li
  • Publication number: 20180204443
    Abstract: A technique capable of immediately reporting to an operator an occurrence of abnormality in an electric tool is provided. A communication terminal 100 includes a communication-terminal-side control unit that determines whether abnormality has occurred in any of electric tools 10, 200, 300, and 400 based on information acquired from the electric tools 10, 200, 300, and 400 via wireless communication. When the communication-terminal-side control unit determines the occurrence of abnormality in any one of the electric tools 10, 200, 300, and 400, the occurrence of abnormality in the electric tool 10, 200, 300, or 400 is reported by at least one of a report unit included in the electric tools 10, 200, 300, and 400 other than the electric tool 10, 200, 300, or 400 in which the occurrence of abnormality is determined and a report unit included in the communication terminal 100.
    Type: Application
    Filed: March 13, 2018
    Publication date: July 19, 2018
    Inventors: Tomomasa NISHIKAWA, Takuya KONNAI, Tatsuya ITO
  • Publication number: 20180161891
    Abstract: To provide a cutting machine that suppresses swinging of the cutting portion when the battery pack is attached or detached, the cutting machine includes a cutting portion, a base, and a swing support mechanism. The cutting portion includes: a motor, a motor housing accommodating the motor, an output shaft configured to be rotated upon rotation of the motor, a battery pack serving as a power source of the motor, and a battery pack attaching portion including a pair of rail portions with which the battery pack is engageable, where a cutting blade is configured to be detachably attached to the output shaft. The base has a contact surface on which a workpiece is configured to be placed. The swing support mechanism is connected to the base and the cutting portion and includes a swing shaft extending in parallel to the output shaft.
    Type: Application
    Filed: April 29, 2016
    Publication date: June 14, 2018
    Inventor: Tomomasa Nishikawa
  • Patent number: 9970445
    Abstract: To provide a portable blower having excellent battery heat radiating properties. A battery mounting portion projects convexly into an air passage. Outer surfaces of a bottom surface section and side surface sections of the battery mounting portion form part of an inner surface of the air passage. The battery mounting portion holds a battery pack at an attitude that a center of gravity of the battery pack is as close to a handle portion as possible. Specifically, the battery mounting portion holds the battery pack in such a manner that the greatest surface of the battery pack having a substantially cubic shape faces the handle portion. The battery mounting portion holds the battery pack in such a manner that a longitudinal direction of the battery pack faces the air passage.
    Type: Grant
    Filed: August 19, 2013
    Date of Patent: May 15, 2018
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Seiichi Kodato, Mizuho Nakamura, Tomomasa Nishikawa, Kouji Sagawa
  • Patent number: 9950417
    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: Grant
    Filed: March 29, 2011
    Date of Patent: April 24, 2018
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Yutaka Ito, Katsuhiro Oomori, Mizuho Nakamura, Tomomasa Nishikawa, Hironori Mashiko
  • Patent number: 9940813
    Abstract: A technique capable of immediately reporting to an operator an occurrence of abnormality in an electric tool is provided. A communication terminal 100 includes a communication-terminal-side control unit that determines whether abnormality has occurred in any of electric tools 10, 200, 300, and 400 based on information acquired from the electric tools 10, 200, 300, and 400 via wireless communication. When the communication-terminal-side control unit determines the occurrence of abnormality in any one of the electric tools 10, 200, 300, and 400, the occurrence of abnormality in the electric tool 10, 200, 300, or 400 is reported by at least one of a report unit included in the electric tools 10, 200, 300, and 400 other than the electric tool 10, 200, 300, or 400 in which the occurrence of abnormality is determined and a report unit included in the communication terminal 100.
    Type: Grant
    Filed: January 9, 2015
    Date of Patent: April 10, 2018
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Tomomasa Nishikawa, Takuya Konnai, Tatsuya Ito
  • Patent number: 9869327
    Abstract: A brushless motor is incorporated in one of divided constituent members of a motor casing which is disassembled, and then, the divided constituent members of the motor casing which is disassembled are connected to each other into the motor casing assembled with mgachine screws screwed into machine screw holes. As this occurs, when a wiring of the brushless motor is held by a first stationary blade portion and a second stationary blade portion, the wiring is allowed to lead to an outside of an outer cylindrical portion through a gap defined between the first stationary blade portion and the second stationary blade portion.
    Type: Grant
    Filed: August 15, 2013
    Date of Patent: January 16, 2018
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Seiichi Kodato, Mizuho Nakamura, Tomomasa Nishikawa, Kouji Sagawa
  • 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
  • Patent number: 9833890
    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: Grant
    Filed: May 18, 2012
    Date of Patent: December 5, 2017
    Assignee: HITACHI KOKI CO., LTD.
    Inventors: Tatsuya Ito, Tomomasa Nishikawa, Hironori Mashiko, Mizuho Nakamura, Yoshio Iimura
  • Publication number: 20170297187
    Abstract: In order to provide a driver for reducing reaction generated to a driver main body, the driver 1 includes a nose portion 3 provided in a housing 2 and extending in a longitudinal direction, the nose portion being configured to allow a fastener to pass therethrough, a plunger 7 configured to move in an impact direction parallel to the longitudinal direction to impact the fastener through the nose portion, a weight 8, and a coil spring 9 configured to be compressed by a motor 5 in the longitudinal direction. a release of the compression causing the plunger 7 to move in the impact direction, while causing the weight 8 to move in a counter-impact direction which is away from the plunger 7. The coil spring 9 is provided between the plunger 7 and the weight 8. The coil spring has one end portion urging the plunger 7, and another end portion urging the weight 8.
    Type: Application
    Filed: August 21, 2015
    Publication date: October 19, 2017
    Inventors: Tomomasa NISHIKAWA, Yoshiichi KOMAZAKI, Tetsuhiro HARADA, Norikazu BABA
  • Publication number: 20170259412
    Abstract: In order to suppress a galling phenomenon between an impact member and a rotating member even when a gouging force acts on an impact tool, an inclined portion is provided between a wall portion which is provided between a pair of hammer cams and in a circumferential direction of a through-hole and a bottom portion which is provided in each center portion of the hammer cams and in the circumferential direction of the through-hole, the inclined portion which has a smaller size than a size of the wall portion in the shaft direction of the through-hole and a larger size than a size of the bottom portion in the shaft direction of the through-hole and against which the spindle is pushed when the first pawl and the second pawl are engaged with each other.
    Type: Application
    Filed: July 24, 2015
    Publication date: September 14, 2017
    Inventors: Tomomasa NISHIKAWA, Tetsuhiro HARADA, Satoru MATSUNO
  • Publication number: 20170246735
    Abstract: The present invention provides an electric working machine in which a control board can be disposed without limitations based on a length of a brushless motor in a direction along an axial line. The electric working machine comprises: a brushless motor provided with a rotor and a stator; a motor case and a motor housing in which the brushless motor is stored; a control board which is provided outside of the motor housing in a radial direction of an axial line defined at the center of the rotor, and supports the switching elements; a connection board which is provided in the motor case, and supports the sensors; a through hole provided on the motor case; a through hole provided on the motor housing; and leads and signal lines extending from inside of the motor housing to the outside of the motor housing through the holes.
    Type: Application
    Filed: August 21, 2015
    Publication date: August 31, 2017
    Inventors: Hideyuki HASHIMOTO, Satoshi ABE, Shingo YAMAZAKI, Tomomasa NISHIKAWA, Akira MATSUSHITA
  • Publication number: 20170239804
    Abstract: Provided is an electric work machine that can suppress a temperature increase of a component controlling an electric motor. The electric work machine including a brushless motor that operates a tip tool includes a rectification circuit that converts a voltage to be applied to the brushless motor from an alternating current voltage to a direct current voltage, and a switching circuit that controls the brushless motor, and the rectification circuit is arranged upstream of the switching circuit in a circulation path of the air that cools the rectification circuit and the switching circuit.
    Type: Application
    Filed: September 29, 2015
    Publication date: August 24, 2017
    Inventors: Akira MATSUSHITA, Tomomasa NISHIKAWA, Yuta NOGUCHI, Kuniaki KANBE, Shingo YAMAZAKI