Patents by Inventor Masaru Ishiwata

Masaru Ishiwata 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: 9828021
    Abstract: Disclosed is a power steering apparatus including: a rack shaft that includes a rack, and moves front wheels; a steering wheel-side pinion shaft that includes a pinion meshing with steering wheel-side rack teeth of the rack shaft, and is rotated along with the steering of a steering wheel; an assistance unit-side pinion shaft that includes a pinion meshing with an assistance unit-side rack of the rack shaft, and is driven by an electric motor to rotate so as to assist the rotation of the steering wheel-side pinion shaft; and a steering angle sensor that is provided on the assistance unit-side pinion shaft, and detects a rotational angle of the assistance unit-side pinion shaft.
    Type: Grant
    Filed: March 23, 2016
    Date of Patent: November 28, 2017
    Assignee: SHOWA CORPORATION
    Inventors: Takayuki Ueno, Masaru Ishiwata
  • Patent number: 9777826
    Abstract: A worm biasing structure that biases a worm toward a worm wheel in a biasing direction, includes: a radial bearing that supports the worm in a radial direction; a bearing holder that has a holder hole for accommodating the radial bearing; a biasing member for biasing the radial bearing toward the worm wheel; and a housing that has a housing hole for accommodating the bearing holder, a pair of guide surfaces is formed as defined herein, when the bearing holder is accommodated in the housing hole and the radial bearing is not accommodated in the bearing holder, a distance between the pair of guide surfaces is smaller than or equal to an outer diameter of the radial bearing, and a gap is formed between an outer surface on the outer side of the guide surface and the housing hole.
    Type: Grant
    Filed: December 18, 2014
    Date of Patent: October 3, 2017
    Assignee: SHOWA CORPORATION
    Inventors: Yuusuke Anma, Masaru Ishiwata, Makoto Watanabe
  • Publication number: 20160280253
    Abstract: Disclosed is a power steering apparatus including: a rack shaft that includes a rack, and moves front wheels; a steering wheel-side pinion shaft that includes a pinion meshing with steering wheel-side rack teeth of the rack shaft, and is rotated along with the steering of a steering wheel; an assistance unit-side pinion shaft that includes a pinion meshing with an assistance unit-side rack of the rack shaft, and is driven by an electric motor to rotate so as to assist the rotation of the steering wheel-side pinion shaft; and a steering angle sensor that is provided on the assistance unit-side pinion shaft, and detects a rotational angle of the assistance unit-side pinion shaft.
    Type: Application
    Filed: March 23, 2016
    Publication date: September 29, 2016
    Applicant: Showa Corporation
    Inventors: Takayuki UENO, Masaru ISHIWATA
  • Publication number: 20160025209
    Abstract: A worm biasing structure that biases a worm toward a worm wheel in a biasing direction, includes: a radial bearing that supports the worm in a radial direction; a bearing holder that has a holder hole for accommodating the radial bearing; a biasing member for biasing the radial bearing toward the worm wheel; and a housing that has a housing hole for accommodating the bearing holder, a pair of guide surfaces is formed as defined herein, when the bearing holder is accommodated in the housing hole and the radial bearing is not accommodated in the bearing holder, a distance between the pair of guide surfaces is smaller than or equal to an outer diameter of the radial bearing, and a gap is formed between an outer surface on the outer side of the guide surface and the housing hole.
    Type: Application
    Filed: December 18, 2014
    Publication date: January 28, 2016
    Applicant: SHOWA CORPORATION
    Inventors: Yuusuke ANMA, Masaru ISHIWATA, Makoto WATANABE
  • Patent number: 6390228
    Abstract: A hydraulic power steering apparatus for a vehicle is provided with a main control valve in which a valve opening degree is controlled on the basis of a relative movement between an input shaft interlocking with a steering wheel and an output shaft interlocking with a steering mechanism for turning a steered wheel, a power cylinder mechanism generating a steering assist force, a pump apparatus discharging a fixed flow amount of working oil, a first flow passage including a supply passage communicated with the main control valve, and a control unit controlling an assist control valve. The main control valve controls a supply amount of the working oil in the first flow passage to the power steering apparatus, and the assist control valve controlling a flow amount of a part of the working oil discharged from the pump apparatus is controlled to a set valve opening degree set on the basis of a vehicle speed and an oil pressure of the working oil in the first flow passage, by the control unit.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: May 21, 2002
    Assignee: Showa Corporation
    Inventors: Akihiko Serizawa, Masaru Ishiwata
  • Publication number: 20010032750
    Abstract: A hydraulic power steering apparatus for a vehicle is provided with a main control valve in which a valve opening degree is controlled on the basis of a relative movement between an input shaft interlocking with a steering wheel and an output shaft interlocking with a steering mechanism for turning a steered wheel, a power cylinder mechanism generating a steering assist force, a pump apparatus discharging a fixed flow amount of working oil, a first flow passage including a supply passage communicated with the main control valve, and a control unit controlling an assist control valve. The main control valve controls a supply amount of the working oil in the first flow passage to the power steering apparatus, and the assist control valve controlling a flow amount of a part of the working oil discharged from the pump apparatus 1 is controlled to a set valve opening degree set on the basis of a vehicle speed and an oil pressure of the working oil in the first flow passage, by the control unit.
    Type: Application
    Filed: February 26, 2001
    Publication date: October 25, 2001
    Inventors: Akihiko Serizawa, Masaru Ishiwata