Patents by Inventor Tomofumi Otani

Tomofumi Otani 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: 6213904
    Abstract: A low-noise chain member comprises a bushing, a roller and oil grooves in which a wedge or squeeze effect of a lubricating oil, which is interposed between the bushing and the roller, is effective in reducing noise. The oil grooves are provided on at least one of the outer surface of the bushing and the inner face of the roller. The inner face of the roller is formed with a curved surface so as to conform to the contour of a curved outer surface of the bushing. A clearance between the inner face of the roller and the outer surface of the bushing is not widened around both ends of the roller. Only a small amount of the lubricating oil between the roller and the bushing escapes to the outside, of the roller and bushing, so that a fluid lubricating state between the bushing and the roller is maintained.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: April 10, 2001
    Assignee: Tsubakimoto Chain Co.
    Inventors: Koji Tanaka, Takahisa Ando, Toshio Takahashi, Sachihiko Maeda, Tomofumi Otani
  • Patent number: 5697206
    Abstract: The present invention improves accuracy in the axial dimension of rolled parts for a chain such as bushings, rollers and similar. A rolled part is manufactured by cutting a strip of steel into a rectangular shape to obtain a rectangular base material having a predetermined dimension, The rectangular base material is rolled into a clindrical shape to obtain a cylindrically formed part having cut end surfaces face each other. A core is inserted for rolling the rectangular base material into the cylindrically formed part. The cylindrically formed part is then pressed through a die having a circular opening. The rolled part has a plurality of blind grooves on a surface thereof. While the cylindrically formed part is being pressed through the die having a circular opening, a plastic flow of the material of the cylindrically formed part intensively occurs in a direction toward the blind grooves.
    Type: Grant
    Filed: February 6, 1996
    Date of Patent: December 16, 1997
    Assignee: Tsubakimoto Chain Co.
    Inventors: Tomofumi Otani, Sachihiko Maeda, Shuji Sasamoto, Masaharu Tamaki, Takero Nakagawa, Yoshitaka Yoshimura, Hiroshi Kobayashi
  • Patent number: D373950
    Type: Grant
    Filed: June 14, 1995
    Date of Patent: September 24, 1996
    Assignee: Tsubakimoto Chain Co.
    Inventors: Tomofumi Otani, Joichi Nakamura, Takero Nakagawa, Shuji Sasamoto, Yoshitaka Yoshimura