Patents by Inventor Eiji Okuma

Eiji Okuma 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).

  • Alumina base ceramic sintered body and its manufacturing method
    Patent number: 6133182
    Abstract: This invention provides an alumina base ceramic sintered body excellent in wear resistance with high hardness, also with high strength and high toughness, and particularly suitable for a cutting tool or wear resistant member. This sintered body contains 5-70 % by volume of WC and 5-70% by volume of Ti (C,N) solid solution having a C/N mole ratio ranging from 1:9 to 9:1, the WC and Ti (C,N) having particle sizes of 5 .mu.m or less, respectively.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: October 17, 2000
    Assignee: Nippon Tungsten Co., Ltd.
    Inventors: Toyoshige Sasaki, Mitsuyoshi Nagano, Eiji Okuma, Shinzou Mitomi, Tetsuo Uchiyama, Shigeo Inoue, Haruka Tamura