Patents by Inventor Kazuaki Yokoi

Kazuaki Yokoi 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: 5964398
    Abstract: A vane member comprises a first member and a second member, the first member and the second member are joined by that an insert member whose melting temperature is lower than melting temperatures of the first and second members contacts the first and second members, the insert member is heated to a welding temperature which is lower than the melting temperatures of the first and second members and is higher than the melting temperature of the insert member so that a mutual diffusion between at least an original base component of the insert member and at least an original base component of the first member different from the original base component of the insert member and a mutual diffusion between at least the original base component of the insert member and at least an original base component of the second member different from the original base component of the insert member are caused by the heating, and the mutual diffusions by the heating are continued at least until the original base component of the i
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: October 12, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Akiomi Kohno, Kazuaki Yokoi, Keiji Taguchi, Hiroshi Misumi, Yoshiharu Ueyama, Kazuyuki Koide, Koji Hayashi
  • Patent number: 5400659
    Abstract: An electromagnetic flowmeter comprises a ceramic measuring tube through which fluid to be measured flows, a pair of electromagnetic coils disposed on the outer surface of the measuring tube in the central region thereof at diametrically opposite positions and generating a magnetic field in a direction perpendicular to the direction of flow of the fluid, a pair of measuring electrodes fixed to the outer surface of the measuring tube in the central region thereof at diametrically opposite positions and having electrode axes perpendicular to both the direction of flow of the fluid and the direction of the magnetic field, and a pair of metallic shields fixed to the outer surface of the measuring tube in surrounding relation to the measuring electrodes. A pair of the measuring electrodes and a pair of the metallic shields are fixed to the ceramic measuring tube by a reaction product due to an interface reaction with the ceramic measuring tube under heating.
    Type: Grant
    Filed: February 2, 1993
    Date of Patent: March 28, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Yokoi, Masatsugu Arai, Akiomi Kohno, Yuji Yoshitomi, Yutaka Sakurai, Tamio Ishihara
  • Patent number: 5307687
    Abstract: An electromagnetic flowmeter for measuring the flow rate of a fluid. The flowmeter has a measuring tube made of ceramics and defining a fluid passage therein for the fluid, electrodes having ends exposed to an interior of the measuring tube through holes which are formed in a wall of the measuring tube, a magnetic field generating device disposed around the electrodes, and a case encasing the measuring tube, the electrodes and the magnetic field generating means. A ratio t/R between a wall thickness t and a mean radius R of the measuring tube is determined such that stress generated in the measuring tube by the fluid in the measuring tube does not exceed the rupture stress of the measuring tube. The measuring tube can have flanges on both axial ends thereof, a radial height of the flange from an outer surface of the measuring tube is not greater than the wall thickness of the tube when the tube is made of Al.sub.2 O.sub.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: May 3, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Masatsugu Arai, Akiomi Kohno, Kazuaki Yokoi, Yuuji Yoshitomi, Yutaka Sakurai, Tamio Ishihara
  • Patent number: 4854495
    Abstract: This invention discloses a method of soldering together at least two members selected form metals and ceramics, which comprises successively jointing a high-melting jointing material, a medium-melting jointing material, and a low-melting jointing material, and a sealing structure prepared by this method.The method according to present invention enables the preparation of a sealing structure having a soldered area which is excellent in tightness.
    Type: Grant
    Filed: June 18, 1987
    Date of Patent: August 8, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Yamamoto, Akiomi Kohno, Toshihiri Yamada, Motohiro Satou, Keiji Taguchi, Kazuaki Yokoi
  • Patent number: 4808360
    Abstract: A mold forming method in which a pattern is made of an organic material such as foamed polystyrene and at least a portion of the outer or inner surface of the mold pattern is covered by a thin coating, and surrounded with a mold material. The pattern is then dissolved by a solvent, leaving the coating undissolved. The coating is finally removed by a solvent contained in a slip which is poured into the cavity provided with the coating.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: February 28, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuo Natori, Takashi Shimaguchi, Toshihiro Yamada, Kazuaki Yokoi
  • Patent number: 4795686
    Abstract: The present invention relates to a sodium-sulfur electric cell structure having a specific joint between a cathode tube and an anode tube. The cathode and anode tubes are each made of an iron-nickel base alloy and are joined to each other through the medium of a ceramic ring and an aluminum alloy insert provided on both sides of the ceramic ring. A chromium or chromium-rich layer is formed at the joint boundary between the insert and each tube. The sodium-sulfur electric cell having such a structure eliminates a problem of the occurrence of cracking, improves the airtightness and enables the production of large-sized electric cells.
    Type: Grant
    Filed: August 24, 1987
    Date of Patent: January 3, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Yokoi, Toshihiro Yamada, Hiroyuki Kawamoto
  • Patent number: 4749118
    Abstract: When a ceramic is bonded to a metal having a low thermal expansion, if a Cr layer of a Cr diffusion layer is formed on the surface of the metal and the ceramic is bonded to the metal through this Cr layer or Cr diffusion layer by an Al insert, a bonded structure having a good air-tightness and a high strength is obtained.
    Type: Grant
    Filed: February 2, 1987
    Date of Patent: June 7, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Yokoi, Toshihiro Yamada, Akiomi Kohno, Motohiro Satou, Hiroyuki Kawamoto
  • Patent number: 4624403
    Abstract: The present invention relates to a method for bonding a non-oxide ceramic to a metal through an intermediate material comprising at least one member selected from metals of the Groups VIa and VIII of the Periodic Table. This method is suitably used for bonding of a structural part of a machine, an electronic part and the like.
    Type: Grant
    Filed: December 13, 1984
    Date of Patent: November 25, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Akiomi Kohno, Susumu Hioki, Toshihiro Yamada, Kazuaki Yokoi, Akihiko Yamamoto
  • Patent number: 4561497
    Abstract: In a heat transfer surface having cavity groups and restricted opening groups in an outer surface region, the cavity groups are composed of a plurality of rows of void strip members. The cavity strip members are arranged in parallel on a base member of the heat transfer surface and are laminated in one or more layers. Each strip member has a number of elongate cavities laterally arranged in parallel. The elongate cavities are closed at upper surfaces and have at both ends openings. The adjacent cavities in the same layer are communicated with each other by communicating portions each provided between the cavity strip members and by the openings. The restricted opening groups are formed on the upper surfaces of the communicating portions. The restricted opening groups render the communicating portions in one layer, the communicating portions in another layer and the outside to communicate with each another. The method of manufacturing such a heat transfer surface is also disclosed.
    Type: Grant
    Filed: December 14, 1983
    Date of Patent: December 31, 1985
    Assignees: Hitachi, Ltd., Hitachi Cable Ltd.
    Inventors: Tadakatsu Nakajima, Wataru Nakayama, Takahiro Daikoku, Heikichi Kuwahara, Akira Yasukawa, Katsuhiko Kasuya, Kazuaki Yokoi, Hideo Nakae, Hiromichi Yoshida