Patents by Inventor Masayoshi Ashitaka

Masayoshi Ashitaka 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).

  • Hydraulic power steering apparatus
    Patent number: 7174825
    Abstract: In a hydraulic power steering apparatus, when the relative rotation between input and output shafts which are connected by a torsion bar is converted into the relative rotation between an outer valve element and an inner valve element, the ratio of the relative rotation angle of the latter to the relative rotation angle of the former is varied in accordance with an operating condition of a vehicle. The hydraulic pressure to generate steering assist force is controlled in accordance with the relative rotation angles between both valve elements. The outer valve element is capable of relative coaxial rotation to the input and output shafts, and the inner valve element is formed integrally with the input shaft. A swinging member is supported by first, second and third supporting parts which respectively rotate together with the input shaft, the output shaft or the outer valve element.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: February 13, 2007
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Akihiko Shiina, Yasuhiro Kamatani, Toshiaki Oya, Ryouichi Tokioka, Kazuhiro Watanabe, Yoshimi Kotake, Hiroji Ueda, Katsuyuki Oguchi, Takashi Ohata, Osamu Sano, Masayoshi Ashitaka
  • Hydraulic power steering apparatus
    Publication number: 20060075747
    Abstract: In a hydraulic power steering apparatus, when the relative rotation between input and output shafts which are connected by a torsion bar is converted into the relative rotation between an outer valve element and an inner valve element, the ratio of the relative rotation angle of the latter to the relative rotation angle of the former is varied in accordance with an operating condition of a vehicle. The hydraulic pressure to generate steering assist force is controlled in accordance with the relative rotation angles between both valve elements. The outer valve element is capable of relative coaxial rotation to the input and output shafts, and the inner valve element is formed integrally with the input shaft. A swinging member is supported by first, second and third supporting parts which respectively rotate together with the input shaft, the output shaft or the outer valve element.
    Type: Application
    Filed: October 12, 2005
    Publication date: April 13, 2006
    Applicant: Koyo Seiko Co., Ltd.
    Inventors: Akihiko Shiina, Yasuhiro Kamatani, Toshiaki Oya, Ryouichi Tokioka, Kazuhiro Watanabe, Yoshimi Kotake, Hiroji Ueda, Katsuyuki Oguchi, Takashi Ohata, Osamu Sano, Masayoshi Ashitaka