Patents by Inventor Shunzo Umegaki

Shunzo Umegaki 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: 5718774
    Abstract: A method of producing a bevel gear is provided. The method comprises the steps of forging, from a case hardened and heated blank, a rough shaped bevel gear intermediate product having a toothed portion, outer burrs at a larger diameter end thereof and between adjacent teeth of the toothed portion, and a ring-shaped inner burr in a center hole thereof, setting the rough shaped bevel gear intermediate product in a trimming die during the time the rough shaped bevel gear intermediate product remains in an elevated temperature condition due to heat left therein after the step of forging, and trimming the outer burrs, and moving, after the step of trimming, the rough shaped bevel gear intermediate product from the trimming die to a sizing die in the vicinity of the trimming die and warm sizing the toothed portion in succession to the step of trimming.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: February 17, 1998
    Assignees: Nissan Motor Co., Ltd., Nittan Valve Co., Ltd.
    Inventors: Tetuo Tukamoto, Kiyosi Okawachi, Mitugu Kojima, Shinji Fushimi, Shunzo Umegaki, Takashi Matsumoto
  • Patent number: 5516376
    Abstract: A hardened surface layer is formed in the region of inner and outer surfaces of a hollow material having a central through hole, then the hollow material is hot-forged into a hollow gear-like forged body by a forging die having a first die element with a piercing punch entering into the central through hole of the hollow material from one side thereof and having a second die element with a piercing punch entering into the central through hole of the hollow material from another side thereof. The forging die forms teeth of the gear on the outer side of the hollow material while producing an annular flash in the central through hole of the hollow material between the piercing punches. A distance between the piercing punches in a closed condition of the forging die defines a thickness of the annular flash which is 0.3 mm or more and no greater than 1.3 times (130%) of a depth of the hardened surface layer.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: May 14, 1996
    Assignees: Nissan Motor Co., Ltd., Nittan Valve Co., Ltd.
    Inventors: Tetsuo Tsukamoto, Kiyoshi Ohkawachi, Shinji Fushimi, Shunzo Umegaki, Takashi Matsumoto