Patents by Inventor Masafumi Okumoto

Masafumi Okumoto 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).

  • Power transmission chain, manufacture method thereof and power transmission assembly
    Publication number: 20070149331
    Abstract: A power transmission chain of the invention includes: plural link plates individually including through-holes and arranged in a chain advancing direction and a chain widthwise direction and with predetermined spacing; and plural pins inserted through the through-holes for flexibly interconnecting the link plates. Since the link plates are arranged in the chain widthwise direction with the predetermined spacing, a respective pair of adjoining link plates are prevented from coming into friction contact with each other during the operation of the power transmission chain. Hence, the power transmission chain may be prevented from suffering the decrease of power transmission efficiency.
    Type: Application
    Filed: January 28, 2005
    Publication date: June 28, 2007
    Applicant: JTEKT CORPORATION
    Inventors: Shinji Yasuhara, Shigeo Kamamoto, Nobuki Fukui, Masafumi Okumoto, Masaru Fuse
  • Method of manufacturing torsion bar for vehicle steering device and torsion bar
    Patent number: 7159434
    Abstract: A method of manufacturing a torsion bar includes a first shaping step of reducing a diameter of a round bar steel material according to cold drawing work so as to have a hardness including an inside through a surface layer of 320 or more to 450 or less by Vickers hardness (HV), and a second shaping step of cutting a midway area of the steel material in the longitudinal direction so as to obtain a spring portion.
    Type: Grant
    Filed: March 13, 2003
    Date of Patent: January 9, 2007
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Motonobu Yoshimura, Masafumi Okumoto
  • Method of manufacturing torsion bar for vehicle steering device and torsion bar
    Publication number: 20050115051
    Abstract: A method of manufacturing a torsion bar includes a first shaping step of reducing a diameter of a round bar steel material according to cold drawing work so as to have a hardness including an inside through a surface layer of 320 or more to 450 or less by Vickers hardness (HV), and a second shaping step of cutting a midway area of the steel material in the longitudinal direction so as to obtain a spring portion.
    Type: Application
    Filed: March 13, 2003
    Publication date: June 2, 2005
    Applicant: Koyo SeiKo Co., Ltd
    Inventors: Motonobu Yoshimura, Masafumi Okumoto