Patents by Inventor Hirokazu Takii

Hirokazu Takii 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).

  • Ferrofluid seal apparatus
    Patent number: 5238254
    Abstract: A ferrofluid seal apparatus comprises magnetic fluid holding means for storing a magnetic fluid with one of an inner and an outer elements which are relatively rotated. The magnetic fluid holding means has a storage section for storing a part of the magnetic fluid which flows out of said magnetic fluid holding means.
    Type: Grant
    Filed: February 20, 1992
    Date of Patent: August 24, 1993
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Hirokazu Takii, Tetsuo Oda, Shinji Abe, Kazuya Suzuki, Hirotsugu Kusano
  • Ferrofluid seal apparatus
    Patent number: 5152539
    Abstract: A ferrofluid seal apparatus comprises magnetic fluid holding or positing means for storing or retaining a magnetic fluid in a sealing arrangement wherein inner and outer elements are relatively rotated. The magnetic fluid holding means includes an arrangement for retaining the magnetic fluid which flows out from its original position.
    Type: Grant
    Filed: September 21, 1990
    Date of Patent: October 6, 1992
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Hirokazu Takii, Tetsuo Oda, Shinji Abe, Kazuya Suzuki, Hirotsugu Kusano
  • Ball bearing for use in vacuum and turbo-molecular pump incorporating same
    Patent number: 5139396
    Abstract: A ball ball bearing for use in a vacuum is a sealed full-type ball bearing comprising an inner ring and an outer ring both made of stainless steel, balls made of a ceramic composed primarily of silicon nitride, and stainless steel shield plates. The bearing has enclosed therein a grease of low-volatility composition comprising a diester synthetic oil serving as a base oil, an organic condensation agent and an ethylene tetrafluoride resin additive.
    Type: Grant
    Filed: February 27, 1991
    Date of Patent: August 18, 1992
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Kazuya Suzuki, Hirokazu Takii