Patents by Inventor Takayoshi Morishita

Takayoshi Morishita 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).

  • Ceramic dynamic pressure bearing, motor with bearing, hard disc apparatus and polygon scanner
    Patent number: 6619848
    Abstract: A ceramic dynamic pressure bearing comprising a first member and a second member, wherein the first member and the second member define a dynamic pressure gap therebetween, the first member and the second member relatively rotate around an axis of rotation, the relative rotation generates a fluid dynamic pressure in the dynamic pressure gap, the first member has a first surface directing to the dynamic pressure gap and the second member has a second surface directing to the dynamic pressure gap, and at least one of the first and second surfaces comprises ceramic, the ceramic comprises: a ceramic matrix that is selected from alumina ceramic, zirconia ceramic and silicon nitride ceramic; and 15 vol % to 70 vol % of an electrically-conductive inorganic compound phase based on the total amount of the ceramic, the phase is dispersed in the ceramic matrix, the phase comprises at least one compound selected from tungsten carbide, silicon carbide, conductive oxide, metallic nitride, metallic carbide, metallic boride,
    Type: Grant
    Filed: February 13, 2002
    Date of Patent: September 16, 2003
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Hironobu Ishikawa, Tetsuji Yogo, Takayoshi Morishita
  • Ceramic dynamic pressure bearing, motor with bearing, hard disc apparatus and polygon scanner
    Publication number: 20020159659
    Abstract: A ceramic dynamic pressure bearing comprising a first member and a second member, wherein the first member and the second member define a dynamic pressure gap therebetween, the first member and the second member relatively rotate around an axis of rotation, the relative rotation generates a fluid dynamic pressure in the dynamic pressure gap, the first member has a first surface directing to the dynamic pressure gap and the second member has a second surface directing to the dynamic pressure gap, and at least one of the first and second surfaces comprises ceramic, the ceramic comprises: a ceramic matrix that is selected from alumina ceramic, zirconia ceramic and silicon nitride ceramic; and 15 vol % to 70 vol % of an electrically-conductive inorganic compound phase based on the total amount of the ceramic, the phase is dispersed in the ceramic matrix, the phase comprises at least one compound selected from tungsten carbide, silicon carbide, conductive oxide, metallic nitride, metallic carbide, metallic boride,
    Type: Application
    Filed: February 13, 2002
    Publication date: October 31, 2002
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Hironobu Ishikawa, Tetsuji Yogo, Takayoshi Morishita
  • Sintered ceramic bodies and ceramic working tools
    Patent number: 5994250
    Abstract: A sintered ceramic body which can be worked by electrical discharge machining, has high mechanical strength, and can be worked into sintered ceramic tools which have long life is disclosed. Further, sintered ceramic tools which have long life and scarcely cause flaws in work pieces are provided. The sintered ceramic body comprises ceramic particles having specific particle diameter and particle distribution.
    Type: Grant
    Filed: July 9, 1998
    Date of Patent: November 30, 1999
    Assignee: NGK Spark Plug Company Limited
    Inventors: Keiji Suzuki, Takayoshi Morishita, Tetsuji Yogo
  • Sintered ceramic bodies and ceramic metal working tools
    Patent number: 5916833
    Abstract: A sintered ceramic body which can be worked by electrical discharge machining, has high mechanical strength, and can be worked into sintered ceramic tools which have long life is disclosed. Further, sintered ceramic tools which have long life and scarcely cause flaws in work pieces are provided. The sintered ceramic body comprises ceramic particles having specific particle diameter and particle distribution.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: June 29, 1999
    Assignee: NGK Spark Plug Company Limited
    Inventors: Keiji Suzuki, Takayoshi Morishita, Tetsuji Yogo