Patents by Inventor Eizo Naya

Eizo Naya 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: 5225381
    Abstract: A vacuum switch contact material consists essentially of a mixture of Cu and Cr.sub.x O.sub.y (x=1 to 2, y=0 to 3) wherein Cr.sub.x O.sub.y is in a particulate state, the center part of the particles consists of Cr.sub.2 O.sub.3 (x=2, y=3), and the peripheral part of the particles consists of Cr (x=1, y=0). The Cr.sub.x O.sub.y particles having Cr.sub.2 O.sub.3 central part and Cr periphery can be formed by reducing the surface of Cr.sub.2 O.sub.3 particles. Cu may be infiltrated into the open pores of Cr.sub.x O.sub.y particles after a green compact of Cr.sub.2 O.sub.3 is formed. Alternatively, a mixture of Cr.sub.2 O.sub.y particles and Cu particles may be formed into a green compact, which may then be sintered. Still alternatively, a mixture of Cr.sub.2 O.sub.y particles and Cu particles may be hot-pressed.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: July 6, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura
  • Patent number: 5130068
    Abstract: A vacuum switch contact material consists essentially of a mixture of Cu and Cr.sub.x O.sub.y (x=1 to 2, y=0 to 3) wherein Cr.sub.x O.sub.y is in a particulate state, the center part of the particles consists of Cr.sub.2 O.sub.3 (x=2, y=3), and the peripheral part of the particles consists of Cr (x=1, y=0). The Cr.sub.x O.sub.y particles having Cr.sub.2 O.sub.3 central part and Cr periphery can be formed by reducing the surface of Cr.sub.2 O.sub.3 particles. Cu may be infiltrated into the open pores of Cr.sub.x O.sub.y particles after a green compact of Cr.sub.2 O.sub.3 is formed. Alternatively, a mixture of Cr.sub.2 O.sub.y particles and Cu particles may be formed into a green compact, which may then be sintered. Still alternatively, a mixture of Cr.sub.2 O.sub.y particles and Cu particles may be hot-pressed.
    Type: Grant
    Filed: October 4, 1990
    Date of Patent: July 14, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura
  • Patent number: 5019156
    Abstract: A sintered electric contact material for use in vacuum switch tubes comprises about 50 to 70% by volume of a Cr powder, about 0.1 to 1.15% by volume of a Ti powder, and the remainder of a Cu powder. The sintered material can be obtained advantageously by heating a mixture of the Cr powder, the Ti powder and the Cu powder in a non-oxidizing atmosphere under pressure, at a temperature below the melting point of Cu (the melting point is 1083.degree. C. at normal pressure).
    Type: Grant
    Filed: May 17, 1990
    Date of Patent: May 28, 1991
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura
  • Patent number: 4971866
    Abstract: In manufacturing contact materials which satisfy all the criteria required for use in vacuum switches as to chopping current, circuit breaking performance, withstanding voltage, welding separation force and wear, Cu powder and Ta.sub.2 O.sub.5 powder are mixed, and compressed while heating below the melting point of Cu in a nonoxidizing atmosphere. Alternatively a green compact is first manufactured from Ta.sub.2 O.sub.5 powder or a mixture of Ta.sub.2 O.sub.5 and Cu powder, and molten Cu is made to infiltrate into the compact. Preparing a green compact from a mixture of Cu powder and Ta.sub.2 O.sub.5 powder, it may be sintered at a temperature below the melting point of Cu, re-pressed, and resintered at 400.degree.-900.degree. C. in a nonoxidizing atmosphere.
    Type: Grant
    Filed: January 8, 1990
    Date of Patent: November 20, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura
  • Patent number: 4927989
    Abstract: A contact material for a vacuum circuit breaker having excellent properties, which consists essentially of copper, molybdenum, one member selected from the group consisting of niobium and tantalum, and one or more kinds of low melting point materials.
    Type: Grant
    Filed: April 11, 1989
    Date of Patent: May 22, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura, Seiichi Miyamoto
  • Patent number: 4926017
    Abstract: A pair of electrodes connected to conductors through joining means respectively are arranged in a vacuum switch tube such that current passes when they come into contact, and does not pass when they separate. At least part of the electrodes, the conductors or the joining means is made of materials with vibration absorbing properties.
    Type: Grant
    Filed: March 24, 1988
    Date of Patent: May 15, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shinichi Aoki, Eizo Naya
  • Patent number: 4870231
    Abstract: A contact for a vacuum interrupter, of a material containing copper (Cu), chromium (Cr), molybdenum (Mo), and either tantalum (Ta) or niobium (Nb), has splendid interrupting ability and breakdown voltage ability.
    Type: Grant
    Filed: July 27, 1987
    Date of Patent: September 26, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura
  • Patent number: 4827289
    Abstract: A thermal head for a printer in accordance with the present invention comprises: a substrate (11); a heater layer (12) on the substrate; lead wires (13a and 13b) formed on the heater layer for supplying electric power to the heater layer; and a single protective layer (20) for protecting the heater layer and the lead wires by covering them, the protective layer including an oxide or a nitride.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: May 2, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shiro Tsuji, Eizo Naya, Takashi Yamanaka, Yoshihiro Usui, Hiroshi Ito, Noriyuki Hasebe
  • Patent number: 4784829
    Abstract: A contact material for a vacuum circuit breaker of excellent current breaking property and voltage withstand capability can be made from an alloy composed of copper and boride of tantalum, or an alloy composed of copper, boride of tantalum and titanium, or an alloy composed of copper, chromium, and boride of tantalum.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: November 15, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Mitsuhiro Okumura, Eizo Naya
  • Patent number: 4677264
    Abstract: The present invention provides a contact material for a vacuum circuit breaker containing therein copper (Cu) and chromium (Cr) with further addition of at least one kind of boride selected from borides of chromium (Cr), molybdenum (Mo) and tungsten (W). Such contact material possesses remarkable advantages of having large current breaking capability and high voltage withstand capability.
    Type: Grant
    Filed: December 5, 1985
    Date of Patent: June 30, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Mitsuhiro Okumura, Eizo Naya, Mitsuhiro Harima, Shoji Murakami, Seiichi Miyamoto
  • Patent number: 4626282
    Abstract: Contact material for vacuum circuit breaker according to the present invention contains (1) copper, (2) molybdenum, and (3) niobium or tantalum.
    Type: Grant
    Filed: October 30, 1985
    Date of Patent: December 2, 1986
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura
  • Patent number: 4575451
    Abstract: A contact material for a vacuum circuit breaker consists essentially of copper as the basic component, and, as the other components, 35% by weight or below of chromium and 50% by weight or below of niobium, the total quantity of chromium and niobium in said contact material being 10% by weight and above.
    Type: Grant
    Filed: November 16, 1983
    Date of Patent: March 11, 1986
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Mitsuhiro Okumura
  • Patent number: 4540861
    Abstract: A contact material for use in a vacuum circuit interrupter which simultaneously provides superior current interrupting performance and breakdown voltage. The contact material of the invention includes components of copper, tantalum and at least one of cobalt and iron. Cobalt or iron should be present in an amount of 50 wt % or less, while the combination of tantalum and cobalt or iron should be present in an amount of at least 10 wt %. A fourth component of at least one of titanium, zirconium and aluminum may be added. Also, there may be included a fifth component containing at least one of a low melting point metal, alloys of a low melting point metal, intermetallic compounds of a low melting point metal, and oxides thereof, with the low melting point metal being at least one of bismuth, tellurium, antimony, thallium, lead, selenium, cerium and calcium in an amount of not more than 20 wt %.
    Type: Grant
    Filed: April 12, 1984
    Date of Patent: September 10, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Mitsuhiro Okumura, Eizo Naya, Mitsumasa Yorita, Yasushi Takeya
  • Patent number: 4537743
    Abstract: The disclosed electrode composition for a vacuum switch comprises copper, as a principal ingredient, a low melting point metal such as Bi, Pb, In, Li, Sn or any of their alloys, in a content not exceeding 20% by weight, a first additional metal such as Te, Sb, La, Mg or any of their alloys and a refractory metal such as Cr, Fe, Co, Ni, Ti, W or any of their alloys in a content less than 40% by weight.
    Type: Grant
    Filed: June 25, 1984
    Date of Patent: August 27, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Yamanaka, Yasushi Takeya, Mitsumasa Yorita, Toshiaki Horiuchi, Kouichi Inagaki, Eizo Naya, Michinosuke Demizu, Mitsuhiro Okumura
  • Patent number: 4517033
    Abstract: A contact material for a vacuum circuit breaker consists essentially of copper as the basic component, and, as the other components, 35% by weight or below of chromium and 50% by weight or below of tantalum, the total quantity of chromium and tantalum in said contact material being 10% by weight and above.
    Type: Grant
    Filed: October 31, 1983
    Date of Patent: May 14, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Mitsuhiro Okumura, Eizo Naya, Michinosuke Demizu
  • Patent number: 4499009
    Abstract: The disclosed electrode composition for a vacuum switch comprises copper, as a principal ingredient, a low melting point metal such as Bi, Pb, In, Li, Sn or any of their alloys, in a content not exceeding 20% by weight, a first additional metal such as Te, Sb, La, Mg or any of their alloys and a refractory metal such as Cr, Fe, Co, Ni, Ti, W or any of their alloys in a content less than 40% by weight.
    Type: Grant
    Filed: December 20, 1982
    Date of Patent: February 12, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Yamanaka, Yasushi Takeya, Mitsumasa Yorita, Toshiaki Horiuchi, Kouichi Inagaki, Eizo Naya, Michinosuke Demizu, Mitsuhiro Okumura
  • Patent number: 4486631
    Abstract: A contact for a vacuum circuit breaker is disclosed which contains copper as a first component and also at least two elements of the group of chromium, molybdenum, and tungsten as the other components. Each of these other components is contained in an amount not greater than 40% by weight.
    Type: Grant
    Filed: December 22, 1982
    Date of Patent: December 4, 1984
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eizo Naya, Toshiaki Horiuchi, Yasushi Takeya, Kouichi Inagaki, Michinosuke Demizu, Mitsuhiro Okumura
  • Patent number: 4424429
    Abstract: A contactor for a vacuum type circuit interrupter having a pair of detachable electrodes in a vacuum chamber comprises an electrode obtained by melting or sintering a composition of an electric conductive metal of copper or silver as a main component and at least one metal oxide having a melting point lower than that of said conductive metal of bismuth oxide, thallium oxide, indium oxide, antimony oxide or tellurium oxide as an additive, in vacuum or a reduced atmosphere or a nonoxidative atmosphere.
    Type: Grant
    Filed: December 30, 1981
    Date of Patent: January 3, 1984
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Yamanaka, Kouichi Inagaki, Eizo Naya, Michinosuke Demizu, Mitsuhiro Okumura