Patents by Inventor Nobumasa Umezawa

Nobumasa Umezawa 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).

  • High strength spring steel
    Patent number: 5183634
    Abstract: Disclosed is a high strength spring steel consisting of, in weight percentage, 0.50 to 0.70% C, 1.00 to 2.50% Si, 0.30 to 1.20% Mn, 0.80 to less than 1.20% Cr, 0.05 to 0.3% Mo, 0.05 to 0.30% V, 0.01 to 0.30% Nb, 0.005 to 0.100% Al and the balance being Fe and unavoidable impurities. The steel of the present invention has a high hardness coupled with high toughness and is very useful, especially for springs used in suspension devices or other various industrial machines.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: February 2, 1993
    Assignee: Mitsubishi Steel Mfg. Co., Ltd.
    Inventors: Tsuyoshi Abe, Nobumasa Umezawa, Tatsuo Fukuzumi, Katsuyuki Uchibori, Junji Ozaki, Hiroharu Motomura
  • High strength spring steel
    Patent number: 5118469
    Abstract: Disclosed is a high strength spring steel consisting of, in weight percentage, 0.40 to 0.70% C, 0.50 to 2.00% Si, more than 0.50 to 1.50% Mn, 0.50 to 2.50% Ni, 0.20 to 1.50% Cr, more than 0.60 to 1.50% Mo, 0.01 to 0.50% V, 0.01 to 0.50% Nb, 0.005 to 0.100% Al and the balance being Fe and unavoidable impurities. The steel of the present invention has a high hardness coupled with high toughness and is very useful especially for springs used in suspension devices or other various industrial machines.
    Type: Grant
    Filed: June 25, 1991
    Date of Patent: June 2, 1992
    Assignee: Mitsubishi Steel Mfg. Co., Ltd.
    Inventors: Tsuyoshi Abe, Nobumasa Umezawa, Tatsuo Fukuzumi, Katsuyuki Uchibori
  • Synthetic resin-coated spring and method for making same
    Patent number: 4753423
    Abstract: A synthetic resin-coated spring comprising a spring body and a synthetic resin coating layer formed on the spring body. The synthetic resin coating layer contains an olefin polymer modified with an unsaturated carboxylic acid or a derivative thereof. A method for making the coated spring is also described.
    Type: Grant
    Filed: May 30, 1986
    Date of Patent: June 28, 1988
    Assignees: Nippon Petrochemicals Co., Ltd, Mitsubishi Steel Manufacture Co., Ltd.
    Inventors: Kenji Ukai, Katsumi Yano, Nobumasa Umezawa, Satoru Yamaguchi, Takao Itoga