Patents by Inventor Tomohisa Kito

Tomohisa Kito 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).

  • Method of producing silicon-nitride-based sintered body
    Patent number: 5122486
    Abstract: Silicon-nitride-based sintered body is produced by a primary sintering; applying a paste-like coating, in which a surface-homogenizing agent is at least one kind of inorganic constituents selected from the group consisting of C, Bn, AlN and Si.sub.3 N.sub.4 provided that C is present at least 5% by weight of the inorganic constituents, on a primary sintered body; and subsequently performing a secondary sintering under a pressure higher than that at the primary sintering.
    Type: Grant
    Filed: February 14, 1989
    Date of Patent: June 16, 1992
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Tomohisa Kito, Katsuhisa Yabuta, Masakazu Watanabe
  • Turbine rotor
    Patent number: 4878812
    Abstract: A turbine rotor having a ceramic turbine wheel having an improved resistance to cracking and breaking. The turbine wheel is made of a ceramic material having pores formed therein with a maximum diameter of 20 .mu.m distributed in the blade portion of the wheel at a porosity of 2 to 10 vol. %. Preferably, the volume porosity of the pores is gradually decreased from the blade surface to the interior of the blade portions.
    Type: Grant
    Filed: June 3, 1988
    Date of Patent: November 7, 1989
    Assignee: NGK Spark Plug, Co., Ltd.
    Inventors: Tomohisa Kito, Katsuhisa Yabuta, Yoshinori Hattori