Patents by Inventor Ryunosuke Kumagai

Ryunosuke Kumagai 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: 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: 9016397
    Abstract: A suspending attachment attached to a cylindrical housing of an electric power tool whose output shaft protrudes from a housing distal end includes a ring-shaped distal end portion fitted to the housing distal end, lower retaining portions of which front ends are connected to the distal end portion and extending rearward along a housing lower-half outer surface with a space through which the housing does not radially come off, one upper retaining portion of which a front end is connected to the distal end portion and extending rearward along a housing upper-half outer surface with a space from each lower retaining portion, through which the housing does not come off, a hook portion extending from at least one of rear ends of the lower and upper retaining portions rearward of the housing, and a connecting member coupling the lower and upper retaining portions over a housing rear surface.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: April 28, 2015
    Assignee: Makita Corporation
    Inventors: Takao Kuroyanagi, Hidenori Nagasaka, Ryunosuke Kumagai
  • Publication number: 20150041169
    Abstract: An impact driver includes a motor, a spindle rotated by the motor, a hammer that is movable forward and rearward with respect to the spindle and that has an inner peripheral portion facing the spindle, and an anvil struck in a rotational direction by the hammer. A grease supply path is provided to supply grease to the inner peripheral portion of the hammer.
    Type: Application
    Filed: July 1, 2014
    Publication date: February 12, 2015
    Inventors: Ryunosuke KUMAGAI, Tokuo HIRABAYASHI
  • Patent number: 8952581
    Abstract: An electric tool may include a motor housing and a motor disposed within the motor housing. The motor has a stator fixed in position relative to the motor housing and a rotor rotatable about a motor axis. Cooling air can flow within the motor housing across the motor in a direction substantially parallel to the motor axis. A baffle may be disposed within the motor housing for regulating the flow of cooling air across the motor. At least a part of the baffle may be positioned within a range of a length of the stator with respect to the axial direction of the motor axis.
    Type: Grant
    Filed: July 31, 2012
    Date of Patent: February 10, 2015
    Assignee: Makita Corporation
    Inventors: Akira Naito, Hidenori Nagasaka, Ryunosuke Kumagai
  • Publication number: 20150027743
    Abstract: An electric power tool capable of suppressing damage to a fan housed in a housing to cool a motor due to foreign matter without increasing the number of parts. An impact driver includes a motor, a centrifugal fan attached to an output shaft of the motor to cool the motor, an annular air collecting member disposed between the motor and the centrifugal fan to collect cooling air by the centrifugal fan, a housing that houses the motor, the centrifugal fan, and the air collecting member, and ventilation windows formed in the housing to communicate between the inside and the outside of the housing on the outer side of the centrifugal fan. The air collecting member is provided with wall bodies positioned on the inner side of the ventilation windows.
    Type: Application
    Filed: December 6, 2012
    Publication date: January 29, 2015
    Applicant: MAKITA CORPORATION
    Inventor: Ryunosuke Kumagai
  • Patent number: 8827003
    Abstract: To ensure that a hammer can retract by a sufficient amount without interfering with a washer receiving a rear end of a coil spring, there is disclosed an impact driver having a washer receiving a rear end of a coil spring biasing a hammer of an impact mechanism to an advanced position. The washer is annular with an inner diameter larger than an inner diameter of an annular groove disposed on a rear surface of the hammer, and includes a frontward extended portion disposed at an inner circumference of the washer. Between a carrier portion of the spindle and the washer, there is disposed a positioner that positions the washer coaxially with the spindle.
    Type: Grant
    Filed: May 25, 2011
    Date of Patent: September 9, 2014
    Assignee: Makita Corporation
    Inventors: Hidenori Nagasaka, Ryunosuke Kumagai
  • Publication number: 20140190718
    Abstract: The present invention provides a rechargeable electric tool in which a battery pack detachably mounted to a mounting part, which is formed lower than an opening provided at a housing, wherein a seal member is held in the housing to seal between the opening and the battery pack mounted to the mounting part. A projection projecting toward the opening side is provided at the seal member, and a passing hole that penetrates the projection and the seal member and allows a lead line connecting an electric component accommodated on the opening side in the housing to the battery pack to pass therethrough is formed.
    Type: Application
    Filed: March 13, 2014
    Publication date: July 10, 2014
    Applicant: MAKITA CORPORATION
    Inventors: Hidenori NAGASAKA, Ryunosuke KUMAGAI
  • Publication number: 20140182869
    Abstract: An impact driver or impact tool includes a motor, a motor housing that houses the motor, a grip housing integrally provided with the motor housing, a hammer case is disposed frontward of the motor housing, a spindle rotated by the motor, a hammer housed inside the hammer case and configured to be rotated by the spindle, and an anvil housed inside the hammer case which anvil is configured to be impacted by the hammer. In this impact driver, a length from a rear end of the motor housing to a front end of the anvil (i.e., the front-rear length of a main body) is less than 128 mm.
    Type: Application
    Filed: October 28, 2013
    Publication date: July 3, 2014
    Applicant: MAKITA CORPORATION
    Inventors: Ryunosuke KUMAGAI, Tokuo HIRABAYASHI, Hidenori NAGASAKA, Manabu SUGIMOTO
  • Patent number: 8733471
    Abstract: The present invention provides a rechargeable electric tool in which a battery pack as a power supply slides in a battery holder formed in an end part of a housing. A bag-shaped waterproof cover covering the battery pack including a coupling part between the battery holder and the battery pack is formed by two divided covers which are separated to the front and rear sides in a slide attachment direction of the battery pack. Between the two divided covers, a coupling mechanism can be moved to a coupling position or a coupling cancelling position. The coupling position is a position in which the divided covers are coupled to each other in an attached state where the coupling part and the battery pack are covered. The coupling cancelling position is a position in which coupling of the divided covers is cancelled.
    Type: Grant
    Filed: August 30, 2011
    Date of Patent: May 27, 2014
    Assignee: Makita Corporation
    Inventors: Hidenori Nagasaka, Ryunosuke Kumagai
  • Patent number: 8708063
    Abstract: The present invention provides a rechargeable electric tool in which a battery pack detachably mounted to a mounting part, which is formed lower than an opening provided at a housing, wherein a seal member is held in the housing to seal between the opening and the battery pack mounted to the mounting part. A projection projecting toward the opening side is provided at the seal member, and a passing hole that penetrates the projection and the seal member and allows a lead line connecting an electric component accommodated on the opening side in the housing to the battery pack to pass therethrough is formed.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: April 29, 2014
    Assignee: Makita Corporation
    Inventors: Hidenori Nagasaka, Ryunosuke Kumagai
  • Publication number: 20140091648
    Abstract: In an electric power tool in which an electric motor is mounted in a housing that has a half-split structure, positions of middle screw fastening portions when a left housing and a right housing are fixed to each other by screws are located between a front protruding coil portion and a rear protruding coil portion. In other words, the protruding coil portions are located on either the front side or the rear side of the position of middle screw fastening portions when the left and right housings are fixed to each other by the screws. Accordingly, it is possible to effectively utilize a dead space that is likely to be formed between the front protruding coil portion and the rear protruding coil portion.
    Type: Application
    Filed: September 16, 2013
    Publication date: April 3, 2014
    Applicant: MAKITA CORPORATION
    Inventor: Ryunosuke KUMAGAI
  • Patent number: 8607893
    Abstract: The cover is provided with engaging pieces that engage with a recessed groove provided on the outer peripheral surface of a hammer case and hold the cover on the hammer case to prevent the cover from being detached. The cover is also provided with bumper receiving portions extending from the front end of the cover and allowing the bumper to be externally attached to the cover, and engaging claws formed on the bumper receiving portions and engaging with engaged recessed portions formed on the inner peripheral surface of the bumper for holding the bumper to prevent the bumper from being detached from the cover. The cover with the bumper attached to the bumper receiving portions is provided to the hammer case.
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: December 17, 2013
    Assignee: Makita Corporation
    Inventors: Ryunosuke Kumagai, Hidenori Nagasaka, Manabu Sugimoto
  • Patent number: 8573322
    Abstract: A hook for electric power tools is disclosed. The hook is used with an electric power tool comprising a handle and a battery pack detachably mounted to a lower end portion of the handle. The hook is designed to be attached to the electric power tool in the proximity of the lower end portion of the handle and includes a ring-shaped slip-off preventing portion having an opening into which, when the battery pack is not attached to the handle, the handle can be inserted into the opening of the slip-off preventing portion, and when the battery pack is attached to the handle, the slip-off preventing portion can be prevented from being pulled out from the handle by the battery pack attached to the handle.
    Type: Grant
    Filed: November 19, 2010
    Date of Patent: November 5, 2013
    Assignee: Makita Corporation
    Inventors: Hidenori Nagasaka, Ryunosuke Kumagai
  • Patent number: 8490732
    Abstract: An electric wheeled apparatus comprises a main body, a drive wheel supported by the main body in a rotatable manner, an electric motor configured to apply torque to the drive wheel, a battery holder configured to removably receive a plurality of battery packs, and a circuit unit configured to electrically connect one or more battery packs attached to the battery holder to the motor regardless of a number of battery packs attached to the battery holder.
    Type: Grant
    Filed: April 26, 2011
    Date of Patent: July 23, 2013
    Assignee: Makita Corporation
    Inventors: Manabu Sugimoto, Ryunosuke Kumagai, Kenichi Kawai
  • Publication number: 20130180368
    Abstract: In an impact driver, a supporting ring, to which a carabiner and so on of a socket is connected, is provided in a shaft support portion in a front end of a hammer case so that the supporting ring is able to be attached and detached by using a screw. Further, a falling prevention element (wire) is provided in the supporting ring. The falling prevention element comes to a position adjacent to the screw which clamps the supporting ring so that the supporting ring is prevented from falling from the impact driver.
    Type: Application
    Filed: December 4, 2012
    Publication date: July 18, 2013
    Inventors: Ryunosuke KUMAGAI, Tokuo HIRABAYASHI, Takao KUROYANAGI, Manabu SUGIMOTO
  • Patent number: 8443913
    Abstract: A hook for an electric power tool is engageable with a carabiner comprising a hook end portion, and a gate member capable of opening the hook end portion. The hook includes: a base portion attached to a housing of a rechargeable electric power tool; an engagement portion positioned outside the base portion and having a first through-hole; a folded-back portion connecting the base portion and the engagement portion and having a second through-hole; and an outer abutment portion formed between the first and second through-holes and configured to cause the gate member to be bent inwardly when the gate member is pressed against the outer abutment portion. The outer abutment portion is engaged with the carabiner by inserting the hook end portion into the first and second through-holes, while the gate member is pressed against the outer abutment portion to open the hook end portion.
    Type: Grant
    Filed: October 25, 2010
    Date of Patent: May 21, 2013
    Assignee: Makita Corporation
    Inventors: Hidenori Nagasaka, Ryunosuke Kumagai, Shinsuke Okuda
  • Patent number: D677137
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: March 5, 2013
    Assignee: Makita Corporation
    Inventors: Tomonori Kawase, Ryunosuke Kumagai
  • Patent number: D679160
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: April 2, 2013
    Assignee: Makita Corporation
    Inventors: Shinsuke Okuda, Ryunosuke Kumagai