Patents by Inventor Tamihito Kawahigashi

Tamihito Kawahigashi 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).

  • Patent number: 6953761
    Abstract: An aluminum nitride sintered body produced by sintering under pressure of a powder composition comprising aluminum nitride and 5 to 30% by weight of at least one sintering aid selected from the group consisting of Nd, Sm, Eu, Er, Dy, Gd, Pr and Yb, per 100% by weight of the powders of aluminum nitride and the sintering aid, wherein the amount of the sintering aid is a conversion value as oxides of the elements, the sintering body that has been subjected to mirror-polishing having a surface roughness R max of 0.2 ?m or less and a thermal conductivity of 200 (W/mK) or more.
    Type: Grant
    Filed: July 30, 2003
    Date of Patent: October 11, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Tanaka, Akio Chiba, Yasutaka Suzuki, Kazuhiro Hirose, Tamihito Kawahigashi
  • Publication number: 20040126598
    Abstract: An aluminum nitride sintered body produced by sintering under pressure of a powder composition comprising aluminum nitride and 5 to 30% by weight of at least one sintering aid selected from the group consisting of Nd, Sm, Eu, Er, Dy, Gd, Pr and Yb, per 100% by weight of the powders of aluminum nitride and the sintering aid, wherein the amount of the sintering aid is a conversion value as oxides of the elements, the sintering body that has been subjected to mirror-polishing having a surface roughness R max of 0.2 &mgr;m or less and a thermal conductivity of 200 (W/mK) or more.
    Type: Application
    Filed: July 30, 2003
    Publication date: July 1, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Shigeru Tanaka, Akio Chiba, Yasutaka Suzuki, Kazuhiro Hirose, Tamihito Kawahigashi
  • Patent number: 5718519
    Abstract: A slide bearing fashioned as a ball bearing or a roller bearing, wherein contact portions of a roll shaft and a bearing, and rolling elements are formed of a combination of a ceramic material and a solid lubricant material. The slide bearing is advantageously utilized in a continuous hot dipping apparatus in which ball bearings or roller bearings are used as bearings of a sink roll and guide rolls of the apparatus.
    Type: Grant
    Filed: January 19, 1996
    Date of Patent: February 17, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takahiko Ookouchi, Tamihito Kawahigashi
  • Patent number: 5711613
    Abstract: A slide structure comprises a roll shaft and a roll bearing. A whole circumference of the roll shaft is made of a sintered ceramics body. A sliding surface of the roll bearing is constructed by inserting a cermet into a carbon-carbon reinforcing graphite member. A continuous hot dipping apparatus has a roll supported and rotated in a molten metal bath. A sliding surface of the roll shaft and the roll bearing employs the slide structure. The corrosion resistivity and the wearing resistivity can be improved and a long service life can be attained. The slide structure comprised of the roll shaft and the roll bearing can be smoothly rotated by decreasing the friction coefficient of the slide structure.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: January 27, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takahiko Ookouchi, Tamihito Kawahigashi, Hitoshi Okoshi, Yoshitaka Nakayama, Junji Sakai, Mitsuo Nakagawa
  • Patent number: 5571327
    Abstract: A continuous hot dipping apparatus which comprises a slide bearing structure of a bearing and a roll shaft which is of a combination of a ceramic material and a solid lubricant material, and which has good wear resistance and long term durability. A heat resistant steel is provided, which is used in a molten metal of hot dipping and which essentially consists of 0.15-0.30% C, not more than 20% Si, not more than 2% Mn, 20-30% Cr, 10-20% Ni and not less than 50% Fe.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: November 5, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Takahiko Ookouchi, Tamihito Kawahigashi, Masatoshi Seki, Junji Sakai, Hitoshi Okoshi, Yoshitaka Nakayama
  • Patent number: 5538558
    Abstract: A slide bearing fashioned as a ball bearing or a roller bearing, wherein contact portions of a roll shaft and a bearing, and rolling elements are formed of a combination of a ceramic material and a solid lubricant material. The slide bearing is advantageously utilized in a continuous hot dipping apparatus in which ball bearings or roller bearings are used as bearings of a sink roll and guide rolls of the apparatus.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: July 23, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Takahiko Ookouchi, Tamihito Kawahigashi