Patents by Inventor Takao Tomonaga

Takao Tomonaga 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: 7364000
    Abstract: The invention provides a suspension apparatus of a vehicle comprising a base end portion of a swing arm pivotally attached to a vehicle body so as to freely oscillate, and a wheel which is rotatably supported to a leading end portion of the swing arm. A first link is pivotally attached to a portion between the base end portion and the leading end portion of the swing arm. A second link is pivotally attached to a position which is below a pivot point to which the base end portion of the swing arm is pivotally attached in the vehicle body, and the first link and the second link are pivotally attached. One end of a cushion unit is pivotally attached to the vehicle body. Another end of the cushion unit is pivotally attached to one of the first link and the second link, in which the first link or the second link comprises an expandable link. The expandable link is energized in a contracting direction.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: April 29, 2008
    Assignee: Showa Corporation
    Inventors: Masataka Furukawa, Takao Tomonaga
  • Publication number: 20080053764
    Abstract: A front fork including an axle side tube, an axle bracket connected to the axle side tube, and a damper cylinder is disclosed. A lower end of the damper cylinder is held between the axle bracket and a lower end of the axle side tube. Furthermore, a damping force generating apparatus is provided in the axle bracket, and an inner portion and an outer portion of the damper cylinder are communicated via the damping force generating apparatus.
    Type: Application
    Filed: March 15, 2007
    Publication date: March 6, 2008
    Applicant: Showa Corporation
    Inventors: Takao Tomonaga, Yosuke Murakami, Daiki Takehana
  • Publication number: 20080053765
    Abstract: A front fork is disclosed. The front fork includes an axle side tube slidably connected to a vehicle body side tube; an axle bracket attached to a lower end of the axle side tube; a damper cylinder extending up from a side of the lower end of the axle side tube, wherein a piston rod is inserted into the damper cylinder and connected to an upper end side of the vehicle body side tube; and an oil lock collar provided in a bottom portion side of the damper cylinder, and an oil lock piece is provided at a leading end side of the piston rod. Furthermore, a damping force generating apparatus is provided in the axle bracket, and an inner portion and an outer portion of the damper cylinder are communicated via the damping force generating apparatus.
    Type: Application
    Filed: March 15, 2007
    Publication date: March 6, 2008
    Applicant: Showa Corporation
    Inventors: Takao Tomonaga, Yosuke Murakami, Daiki Takehana
  • Patent number: 7204354
    Abstract: In a rotary damper, an outer lid is attached to an outer side surface of a casing. A first oil passage and a second oil passage are in respective communication. A first oil chamber and a second oil chamber are provided in parallel between the outer side surface of the casing and the inner side surface of the outer lid. A first check valve is provided in the first oil passage, a second check valve is provided in the second oil passage, and an orifice plate is movably provided so as to face both the first oil passage and the second oil passage.
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: April 17, 2007
    Assignee: Showa Corporation
    Inventor: Takao Tomonaga
  • Publication number: 20070045982
    Abstract: In a steering damper apparatus, a steering shaft is pivoted to a head pipe arranged in a front portion of a vehicle body frame, a rotary type viscous fluid damper is arranged in a rear side of the head pipe of the vehicle body frame, a linkage is wound around a drive wheel provided in the steering shaft and a driven wheel provided in a rotating shaft of the viscous fluid damper, and a diameter of the drive wheel is larger than a diameter of the driven wheel.
    Type: Application
    Filed: March 14, 2006
    Publication date: March 1, 2007
    Applicant: Showa Corporation
    Inventor: Takao Tomonaga
  • Patent number: 7048291
    Abstract: A front fork in a two-wheeled vehicle or the like, wherein an annular groove in which both end portions in an axial direction are closed is formed in an upper inner periphery of an outer tube. An annular bush having a closed gap in a free state is attached to the annular groove. An annular gap between an inner periphery of the outer tube and an outer periphery of the inner tube forms a smaller thickness than the bush.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: May 23, 2006
    Assignee: Showa Corporation
    Inventors: Kazuo Wada, Shinichi Oba, Takao Tomonaga, Koichi Nakano
  • Patent number: 6997293
    Abstract: In a front fork of a motor cycle or the like, an outer peripheral portion of a seat member is clamped and fixed between a bottom portion of an axle bracket and a lower end portion of an axle side tube. A flange portion is provided in an outer periphery of a lower end portion of a holder provided with a compression side partition wall member and valve assembly. An outer periphery of a lower end portion of a damper cylinder is screwed with the seat member. The outer peripheral flange portion of the holder is clamped and fixed between the lower end portion of the damper cylinder and the bottom portion of the axle bracket or the seat member.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: February 14, 2006
    Assignee: Showa Corporation
    Inventors: Takao Tomonaga, Munemitu Eguchi
  • Publication number: 20050274582
    Abstract: In a rotary damper, an outer lid is attached to an outer side surface of a casing. A first oil passage and a second oil passage are in respective communication. A first oil chamber and a second oil chamber are provided in parallel between the outer side surface of the casing and the inner side surface of the outer lid. A first check valve is provided in the first oil passage, a second check valve is provided in the second oil passage, and an orifice plate is movably provided so as to face both the first oil passage and the second oil passage.
    Type: Application
    Filed: December 14, 2004
    Publication date: December 15, 2005
    Inventor: Takao Tomonaga
  • Patent number: 6918605
    Abstract: An inverted type front fork in a two-wheeled vehicle or the like, wherein an annular groove in which both end portions in an axial direction are closed is formed in an upper inner periphery of an outer tube, and an annular bush having a closed gap in a free state is attached to the annular groove, and an annular gap between an inner periphery of the outer tube and an outer periphery of the inner tube forms a smaller thickness than the bush.
    Type: Grant
    Filed: November 25, 2003
    Date of Patent: July 19, 2005
    Assignee: Showa Corporation
    Inventors: Kazuo Wada, Shinichi Oba, Takao Tomonaga
  • Publication number: 20050145456
    Abstract: In a front fork of a motor cycle or the like, an outer peripheral portion of a seat member is clamped and fixed between a bottom portion of an axle bracket and a lower end portion of an axle side tube. A flange portion is provided in an outer periphery of a lower end portion of a holder provided with a compression side partition wall member and valve assembly. An outer periphery of a lower end portion of a damper cylinder is screwed with the seat member. The outer peripheral flange portion of the holder is clamped and fixed between the lower end portion of the damper cylinder and the bottom portion of the axle bracket or the seat member.
    Type: Application
    Filed: June 14, 2004
    Publication date: July 7, 2005
    Inventors: Takao Tomonaga, Munemitu Eguchi
  • Publication number: 20050116437
    Abstract: The invention provides a suspension apparatus of a vehicle comprising a base end portion of a swing arm pivotally attached to a vehicle body so as to freely oscillate, and a wheel which is rotatably supported to a leading end portion of the swing arm. A first link is pivotally attached to a portion between the base end portion and the leading end portion of the swing arm. A second link is pivotally attached to a position which is below a pivot point to which the base end portion of the swing arm is pivotally attached in the vehicle body, and the first link and the second link are pivotally attached. One end of a cushion unit is pivotally attached to the vehicle body. Another end of the cushion unit is pivotally attached to one of the first link and the second link, in which the first link or the second link comprises an expandable link. The expandable link is energized in a contracting direction.
    Type: Application
    Filed: June 4, 2004
    Publication date: June 2, 2005
    Inventors: Masataka Furukawa, Takao Tomonaga
  • Publication number: 20050074189
    Abstract: A front fork in a two-wheeled vehicle or the like, wherein an annular groove in which both end portions in an axial direction are closed is formed in an upper inner periphery of an outer tube. An annular bush having a closed gap in a free state is attached to the annular groove. An annular gap between an inner periphery of the outer tube and an outer periphery of the inner tube forms a smaller thickness than the bush.
    Type: Application
    Filed: June 8, 2004
    Publication date: April 7, 2005
    Inventors: Kazuo Wada, Shinichi Oba, Takao Tomonaga, Koichi Nakano
  • Publication number: 20050073128
    Abstract: An inverted type front fork in a two-wheeled vehicle or the like, wherein an annular groove in which both end portions in an axial direction are closed is formed in an upper inner periphery of an outer tube, and an annular bush having a closed gap in a free state is attached to the annular groove, and an annular gap between an inner periphery of the outer tube and an outer periphery of the inner tube forms a smaller thickness than the bush.
    Type: Application
    Filed: November 25, 2003
    Publication date: April 7, 2005
    Inventors: Kazuo Wada, Shinichi Oba, Takao Tomonaga