Patents by Inventor Takesi Ozawa

Takesi Ozawa 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).

  • Oxide superconducting wire and method of manufacturing the same
    Patent number: 6316391
    Abstract: The present invention provides superconductors capable of being used at temperatures to which the superconductor can be cooled in liquid nitrogen and of carrying current in a high critical current density in a magnetic field, and superconducting apparatuses employing the superconductors and more advantageous in costs than the conventional superconducting apparatuses. A superconducting wire is formed by combining a metallic body of a cubic aggregate structure and an oxide superconducting substance. The present invention provides superconductors, superconducting wires, superconducting magnets and applied superconducting apparatuses having a high superconducting critical current density. The applied super conducting apparatuses employing the superconductors or the superconducting wires in accordance with the present invention are able to operate when cooled in liquid nitrogen-and can be manufactured at costs lower than those of the conventional superconducting apparatuses.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: November 13, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takesi Ozawa, Toyotaka Yuasa, Kazutoshi Higashiyama
  • Permanent current switch and superconducting magnet system
    Patent number: 5757257
    Abstract: Superconducting magnet system using a liquid helium for its operation and a permanent current switch and a system thereof applied to the superconducting magnet system employing a permanent current loop created by a superconducting material developing superconductivity when cooled. The system includes a superconducting magnet dipped in the liquid helium, the permanent current switch for driving or interrupting the superconducting magnet, and a cryostat for accommodating the superconducting magnet and the permanent current switch, and the permanent current switch is arranged over a liquid surface of the liquid helium.
    Type: Grant
    Filed: September 20, 1994
    Date of Patent: May 26, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takesi Ozawa, Katsuzo Aihara, Tomoichi Kamo, Kazuhisa Mori, Nobuhiro Hara
  • Oxide-based superconductor, a process for preparing the same and a wire material of comprising the same
    Patent number: 5545610
    Abstract: An oxide-based superconductor ccmprising Tl, Pb, Sr, Ca and Cu or Tl, Pb, Ba, Sr, Ca and Cu, prepared by subjecting a low melting point composition comprising the superconductor-constituting elements and a solid composition comprising the superconductor-constituting elements, prepared in advance, to reaction under melting conditions for the low melting point composition, has distinguished current pass characteristics in a high magnetic field due to improvement of electric contact among grains through reduction of non-superconductor phase, increase in crystal grain sizes (reduction of crystal boundaries), orientation of crystal and cleaning of crystal boundaries.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: August 13, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Kazutoshi Higashiyama, Toshiya Doi, Takesi Ozawa, Seizi Takeuchi, Tomoichi Kamo, Shinpei Matsuda, Yutaka Yoshida