Patents by Inventor Hiroto Inagawa

Hiroto Inagawa 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: 10035253
    Abstract: A portable work tool includes: a housing; a motor; and a restraining surface. The housing has an outer surface including a covered region that is covered with a soft layer and an uncovered region that is exposed to an outside. The covered region and the uncovered region define a boundary therebetween. The motor is accommodated in the housing. The restraining surface is disposed in proximity to the boundary and protrudes from the covered region.
    Type: Grant
    Filed: January 8, 2014
    Date of Patent: July 31, 2018
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Hiroto Inagawa, Kenji Fukuda
  • Publication number: 20150352706
    Abstract: A portable work tool includes: a housing; and a motor; and a restraining surface. The housing has an outer surface including a covered region that is covered with a soft layer and an uncovered region that is exposed to an outside. The covered region and the uncovered region define a boundary therebetween. The motor is accommodated in the housing. The restraining surface is disposed in proximity to the boundary and protrudes from the covered region.
    Type: Application
    Filed: January 8, 2014
    Publication date: December 10, 2015
    Applicant: HITACHI KOKI CO., LTD.
    Inventors: Hiroto Inagawa, Kenji Fukuda
  • Publication number: 20150034346
    Abstract: An impact tool comprises an end-bit holding section (3a) and a driving source (2). The end-bit holding section is formed with a hole (3a) for receiving an end bit (12), the hole having a center axis defining an axial direction, the hole having one end in the axial direction functioning as an end-bit insertion opening (3c) for passing the end bit therethrough, the hole having a generally polygonal cross section perpendicular to the axial direction. The driving source is configured to rotate the end-bit holding section. An arc-shaped cutout (3g) is formed at each apex angle of the hole in proximity to the end-bit insertion opening such that the arc-shaped cutout has a largest arc dimension at the opening (3c) and the arc dimension decreases gradually from the opening toward another end of the hole in the axial direction.
    Type: Application
    Filed: March 25, 2013
    Publication date: February 5, 2015
    Inventors: Norihide Tao, Hiroto Inagawa, Hideki Watanabe
  • Patent number: 8522519
    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: Grant
    Filed: September 15, 2011
    Date of Patent: September 3, 2013
    Assignee: Hitachi Koko Co., Ltd.
    Inventors: Kenji Kobori, Hiroto Inagawa, Tomomasa Nishikawa
  • 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
  • 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
  • Patent number: 7721818
    Abstract: A power tool includes: a power tool main body; a handle holder protruding from the power tool main body; a handle extending in a protruding direction of the handle holder and having an arm portion engaging the handle holder; and an elastic body carried between the power tool main body and the handle. The handle holder has a spherical convex outer circumferential face. The arm portion surrounds the handle holder and has a spherical concave inner circumferential face. The convex outer circumferential face of the handle holder is inserted and fitted into the concave inner circumferential face. The elastic body is carried between the power tool main body and the handle around the outer circumference of the handle holder in a radial direction vertical to a protruding-direction central axis of the handle holder.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: May 25, 2010
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Hiroto Inagawa, Shinki Ohtsu, Kenji Kobori, Tetsuo Ebata
  • Patent number: 7540722
    Abstract: A blower providing a blower mode and a vacuum mode. A casing provides a motor housing installing a motor and a fan housing installing a centrifugal fan rotationally driven by the motor. A partition is disposed and having a first surface defining a motor housing and second surface defining a fan housing. The fan includes a generally circular base plate having one surface in direct confrontation with the second surface. A plurality of base plate through-holes arrayed in an imaginary circle whose center is coincident with the rotation axis of the fan are formed in the base plate. The partition is formed with a plurality of partition through-holes arrayed in the imaginary circle and in selective alignment with the base plate through-holes in accordance with the rotation of the centrifugal fan. Each partition through-hole includes a width increasing region where a width of the partition through-hole in the circumferential direction is gradually increased toward the second surface.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: June 2, 2009
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Tomomasa Nishikawa, Hiroto Inagawa
  • Patent number: 7458493
    Abstract: A combustion type power tool capable of restraining reduction in output power due to lowering of combustion efficiency. A specific space within a combustion-chamber frame is enlarged. The specific space contains a specific region where high turbulence occurs in a combustion chamber at which a fuel is ignited. The enlargement is made by providing an enlarged distance between a rotation shaft of the fan and an inner wall of the combustion-chamber frame. When the turbulent combustion occurring at the specific region is expanded in the combustion chamber, flame propagation contour of the turbulent combustion reaches the wall of the combustion-chamber frame and ribs at a delayed timing. Therefore, after the turbulent combustion is sufficiently promoted, the flame reaches the combustion-chamber frame and the ribs. In other words, the flame does not reach the combustion-chamber frame and the ribs at the initial stage of turbulent combustion.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: December 2, 2008
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Tomomasa Nishikawa, Hiroto Inagawa
  • Patent number: 7416031
    Abstract: An impact tool comprising a motor, a hammer 8 that is rotated and axially moved by a drive force of the motor, an anvil 3 that repeats engagement/disengagement from the hammer 8 accompanying rotation and axial movements of the hammer 8, and a tip tool 4 mounted to the anvil 3, the anvil 3 comprising a first split piece 3A, which includes pawls 3c (first concave-convex part) on an opposite side to the hammer and repeats engagement/disengagement from the hammer 8, a second split piece 3B, which includes pawls 3f (second concave-convex part) engageable with the pawls (first concave-convex part) 3c of the first split piece 3A in a direction of rotation, and to which the tip tool 4 is mounted, and a rubber damper (elastic body) 13 interposed between the first and second split pieces 3A, 3B to prevent direct contact between the pawls (first concave-convex part) 3c and the pawls (second concave-convex part) 3f in the direction of rotation and in an axial direction.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: August 26, 2008
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Takuhiro Murakami, Junichi Kamimura, Katsuhiro Oomori, Shinki Ohtsu, Hiroto Inagawa
  • Patent number: 7357195
    Abstract: A power tool including a gear unit provided with a load moderating mechanism capable of reducing noise and prolonging service life. A coupling is force fitted with a spindle at a predetermined pressure allowing the spindle and the coupling to rotate relative to each other when a load exceeding a predetermined load is applied therebetween. A gear has a surround section having a convex and surrounding the coupling. The coupling has an abutment projection abutable against the convex and a damper projection. An elastic member is interposed between the damper projection and the surround section. Rotation of the gear is transmitted to the spindle through the elastic member and the coupling.
    Type: Grant
    Filed: April 7, 2005
    Date of Patent: April 15, 2008
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Junichi Kamimura, Hiroto Inagawa, Kenichirou Yoshida, Takashi Kawamata
  • Publication number: 20070179328
    Abstract: An impact tool, which can realize the reduction of noise without inviting the reduction of a fastening ability and which can improve the durability of a damper while preventing its damage. The impact tool includes a rotary impact mechanism mounted on a spindle to be rotationally driven by a motor, so that rotary impact is applied to a tip tool by transmitting the rotary impact intermittently from a hammer through an anvil to the tip tool. A plurality of pawls are formed on two half members of the anvil in the axial direction. A rubber damper is disposed in a space between the pawls arranged alternately in the circumferential direction of the two half members. The minimum sectional area of the space formed between the pawls is set larger than the sectional area of the rubber damper.
    Type: Application
    Filed: January 26, 2007
    Publication date: August 2, 2007
    Inventors: Takuhiro Murakami, Junichi Kamimura, Katsuhiro Oomori, Shinki Ohtsu, Hiroto Inagawa
  • Publication number: 20070034398
    Abstract: An impact tool for reducing noise without lowering the tightening ability. The impact tool gives a rotary blow force to a tip tool by mounting a rotary blow mechanism on a spindle rotatably driven by a motor and intermittently transferring the rotary blow force generated by the rotary blow mechanism from a hammer to the tip tool via an anvil, damping materials absorbing at least the vibration in the radial direction are arranged on at least one side of both supports of the axial direction of the spindle 7. The damping material is interposed between a bearing that rotatably supports the rear end portion of the spindle and an inner cover that holds the same, and an O-ring is interposed as a damping material between the front end portion of the spindle and an anvil that rotatably supports the same.
    Type: Application
    Filed: August 9, 2006
    Publication date: February 15, 2007
    Inventors: Takuhiro Murakami, Junichi Kamimura, Katsuhiro Oomori, Shinki Ohtsu, Hiroto Inagawa, Hideki Watanabe
  • Publication number: 20060254789
    Abstract: An impact tool comprising a motor, a hammer 8 that is rotated and axially moved by a drive force of the motor, an anvil 3 that repeats engagement/disengagement from the hammer 8 accompanying rotation and axial movements of the hammer 8, and a tip tool 4 mounted to the anvil 3, the anvil 3 comprising a first split piece 3A, which includes pawls 3c (first concave-convex part) on an opposite side to the hammer and repeats engagement/disengagement from the hammer 8, a second split piece 3B, which includes pawls 3f (second concave-convex part) engageable with the pawls (first concave-convex part) 3c of the first split piece 3A in a direction of rotation, and to which the tip tool 4 is mounted, and a rubber damper (elastic body) 13 interposed between the first and second split pieces 3A, 3B to prevent direct contact between the pawls (first concave-convex part) 3c and the pawls (second concave-convex part) 3f in the direction of rotation and in an axial direction.
    Type: Application
    Filed: April 7, 2006
    Publication date: November 16, 2006
    Inventors: Takuhiro Murakami, Junichi Kamimura, Katsuhiro Oomori, Shinki Ohtsu, Hiroto Inagawa
  • Publication number: 20060254786
    Abstract: An impact tool includes a rotational impact mechanism which is attached to a spindle 7 rotated and driven by a motor, a rotational impact force generated by the rotational impact mechanism which is intermittently transmitted from a hammer 8 via an anvil 3 to a bit tool 4, thereby giving the rotational impact force to the bit tool 4, and the anvil 3 is provided with a buffer mechanism (rubber damper 13) performing a buffer function in a rotational direction and in an axial direction and also directly transmitting a rotational torque greater than a set value and the spindle 7 is fitted into the anvil 3 and the buffer mechanism (rubber damper 3).
    Type: Application
    Filed: May 8, 2006
    Publication date: November 16, 2006
    Inventors: Takuhiro Murakami, Junichi Kamimura, Katsuhiro Oomori, Shinki Ohtsu, Hiroto Inagawa, Hideki Watanabe
  • Publication number: 20060151565
    Abstract: A combustion type power tool capable of restraining reduction in output power due to lowering of combustion efficiency. A specific space within a combustion-chamber frame is enlarged. The specific space contains a specific region where high turbulence occurs in a combustion chamber at which a fuel is ignited. The enlargement is made by providing an enlarged distance between a rotation shaft of the fan and an inner wall of the combustion-chamber frame. When the turbulent combustion occurring at the specific region is expanded in the combustion chamber, flame propagation contour of the turbulent combustion reaches the wall of the combustion-chamber frame and ribs at a delayed timing. Therefore, after the turbulent combustion is sufficiently promoted, the flame reaches the combustion-chamber frame and the ribs. In other words, the flame does not reach the combustion-chamber frame and the ribs at the initial stage of turbulent combustion.
    Type: Application
    Filed: March 10, 2006
    Publication date: July 13, 2006
    Inventors: Tomomasa Nishikawa, Hiroto Inagawa
  • Patent number: 7066117
    Abstract: A combustion type power tool capable of restraining reduction in output power due to lowering of combustion efficiency. A specific space within a combustion-chamber frame is enlarged. The specific space contains a specific region where high turbulence occurs in a combustion chamber at which a fuel is ignited. The enlargement is made by providing an enlarged distance between a rotation shaft of the fan and an inner wall of the combustion-chamber frame. When the turbulent combustion occurring at the specific region is expanded in the combustion chamber, flame propagation contour of the turbulent combustion reaches the wall of the combustion-chamber frame and ribs at a delayed timing. Therefore, after the turbulent combustion is sufficiently promoted, the flame reaches the combustion-chamber frame and the ribs. In other words, the flame does not reach the combustion-chamber frame and the ribs at the initial stage of turbulent combustion.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: June 27, 2006
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Tomomasa Nishikawa, Hiroto Inagawa
  • Publication number: 20060113098
    Abstract: A power tool includes: a power tool main body; a handle holder protruding from the power tool main body; a handle extending in a protruding direction of the handle holder and having an arm portion engaging the handle holder; and an elastic body carried between the power tool main body and the handle. The handle holder has a spherical convex outer circumferential face. The arm portion surrounds the handle holder and has a spherical concave inner circumferential face. The convex outer circumferential face of the handle holder is inserted and fitted into the concave inner circumferential face. The elastic body is carried between the power tool main body and the handle around the outer circumference of the handle holder in a radial direction vertical to a protruding-direction central axis of the handle holder.
    Type: Application
    Filed: October 28, 2005
    Publication date: June 1, 2006
    Inventors: Hiroto Inagawa, Shinki Ohtsu, Kenji Kobori, Tetsuo Ebata
  • Publication number: 20050224245
    Abstract: A power tool including a gear unit provided with a load moderating mechanism capable of reducing noise and prolonging service life. A coupling is force fitted with a spindle at a predetermined pressure allowing the spindle and the coupling to rotate relative to each other when a load exceeding a predetermined load is applied therebetween. A gear has a surround section having a convex and surrounding the coupling. The coupling has an abutment projection abutable against the convex and a damper projection. An elastic member is interposed between the damper projection and the surround section. Rotation of the gear is transmitted to the spindle through the elastic member and the coupling.
    Type: Application
    Filed: April 7, 2005
    Publication date: October 13, 2005
    Inventors: Junichi Kamimura, Hiroto Inagawa, Kenichirou Yoshida, Takashi Kawamata
  • Publication number: 20050169782
    Abstract: A blower providing a blower mode and a vacuum mode. A casing provides a motor housing installing a motor and a fan housing installing a centrifugal fan rotationally driven by the motor. A partition is disposed and having a first surface defining a motor housing and second surface defining a fan housing. The fan includes a generally circular base plate having one surface in direct confrontation with the second surface. A plurality of base plate through-holes arrayed in an imaginary circle whose center is coincident with the rotation axis of the fan are formed in the base plate. The partition is formed with a plurality of partition through-holes arrayed in the imaginary circle and in selective alignment with the base plate through-holes in accordance with the rotation of the centrifugal fan. Each partition through-hole includes a width increasing region where a width of the partition through-hole in the circumferential direction is gradually increased toward the second surface.
    Type: Application
    Filed: February 3, 2005
    Publication date: August 4, 2005
    Inventors: Tomomasa Nishikawa, Hiroto Inagawa