Patents by Inventor Tsuneyo Seki

Tsuneyo Seki 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: 6303076
    Abstract: A contact material for forming a contact included in a vacuum interrupter comprises 50 to 70% by weight of a conductive material containing Cu as a principal component, an arc-proof material containing at least either TiC or VC and having a mean particle diameter of 8 &mgr;m or below, and 0.2 to 2.0% by weight of Cr on the basis of the sum of the respective amounts of Cr and Cu or 0.2 to 2/0% by weight of Zr on the basis of the sum of the respective amounts of Zr and Cu. The contact material has a hydrogen content in the range of 0.2 to 50 ppm.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: October 16, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Atsushi Yamamoto, Takashi Kusano, Tsutomu Okutomi, Tsuneyo Seki, Makoto Kataoka
  • Patent number: 6210809
    Abstract: The contact material of the present invention comprises: an anti-arcing constituent consisting of at least one TiC, V and VC of which the content is 30˜70 volume % and whose mean particle (grain) size is 0.1˜9 &mgr;m; C whose content is 0.005˜0.5 weight % with respect to the anti-arcing constituent, whose diameter is 0.01˜5 &mgr;m when its shape is calculated as spherical, and which is in non-solid solution condition or condition in which it does not form a chemical compound; and a conductive constituent consisting of Cu and constituting the balance.
    Type: Grant
    Filed: December 31, 1998
    Date of Patent: April 3, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Atsushi Yamamoto, Iwao Ohshima, Tsuneyo Seki, Mitsutaka Homma, Takashi Kusano
  • Patent number: 6107582
    Abstract: A vacuum valve which has a contact material having a constituent of high electrical conductivity such as Cu and an anti-arcing constituent including Cr in which particles whose particle size is in the range 0.1.about.150 .mu.m represent at least 90 volume %, and a ratio defined by the formula (.alpha..sub.900 -.alpha..sub.50).times.100/(.alpha..sub.900) for this contact material has a value of 8-12% and is the coefficient of thermal expansion of the contact material .alpha..sub.50 is the coefficient of thermal expansion of the contact material at 50.degree. C. The formation of channels generated at the interfaces of the Cr particles and the Cu matrix after undergoing the brazing step is suppressed, enabling the static withstand-voltage, contact resistance, and the breaking performance characteristics of the vacuum valve to be stabilized.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: August 22, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Mitsutaka Homma, Tsuneyo Seki, Atsushi Yamamoto, Takashi Kusano, Hiromichi Somei
  • Patent number: 6080952
    Abstract: An electrode arrangement of a vacuum circuit breaker for making and breaking electrical connection. The electrode arrangement has: a pair of contact members which are adopted for making contact to and release from each other by relatively moving to and from each other along a predetermined direction; a pair of electrically conductive bars being connected to the above pair of contact members, respectively, for providing electric conduction to the contact members; and a magnetizing device with a magnetic body for generating magnetic field parallel to the predetermined direction between the contact members. The magnetic body is composed of an iron alloy comprising 0.02 to 1.5% by weight of carbon and iron. The iron alloy may further contain at least one of manganese and silicon.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: June 27, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Tsuneyo Seki, Iwao Ohshima, Mitsutaka Homma, Hiromichi Somei, Kumi Uchiyama, Yoshimitsu Niwa, Kenji Watanabe
  • Patent number: 6027821
    Abstract: A contact material for a vacuum interrupter including, a conductive component including at least Cu, and an arc-proof component including at least one selected from the group consisting of carbides of W, Zr, Hf, V and Ti. An amount of the conductive component in the contact material is 40-50 vol %, an amount of the arc-proof component in the contact material is 50-60 vol %, and a grain size of the arc-proof component is 3 .mu.m or less. A total amount of a sintering activator including at least one selected from the group consisting of Co, Fe and Ni melted in the conductive component is 0.1% or less of the amount of the conductive component.
    Type: Grant
    Filed: December 9, 1996
    Date of Patent: February 22, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Atsushi Yamamoto, Tsuneyo Seki, Takashi Kusano, Tsutomu Okutomi
  • Patent number: 6024896
    Abstract: The contacts material of the present invention is contacts material including silver-tungsten carbide alloy containing 55-70 weight % of tungsten carbide (WC) of mean particle size 0.1-6 .mu.m wherein is included 0.005-0.2 weight % of carbon in an undissolved state or non-compound state whose equivalent diameter is 0.01-5 .mu.m.The present invention enables the current interruption characteristics of contacts material to be improved.
    Type: Grant
    Filed: March 9, 1998
    Date of Patent: February 15, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Atsushi Yamamoto, Tsuneyo Seki, Tadaaki Sekiguchi
  • Patent number: 5972068
    Abstract: The vacuum valve contact material of the present invention is manufactured by a step of mixing an anti-arc constituent powder and a conductive constituent powder, a step of forming, and a step of sintering the formed body below the melting point of the conductive constituent, and has improved arc interruption performance.
    Type: Grant
    Filed: March 6, 1998
    Date of Patent: October 26, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneyo Seki, Atsushi Yamamoto, Takashi Kusano, Tsutomu Okutomi
  • Patent number: 5882448
    Abstract: A contact material for a vacuum valve including, a conductive constituent including at least copper, an arc-proof constituent including at least chromium and an auxiliary constituent including at least one selected from the group consisting of tungsten, molybdenum, tantalum and niobium. The contact material is manufactured by quench solidification of a composite body of the conductive constituent, the arc-proof constituent and the anxiliary constituent.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: March 16, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneyo Seki, Tsutomu Okutomi, Atsushi Yamamoto, Takashi Kusano
  • Patent number: 5726407
    Abstract: A contact electrode for a vacuum interrupter including a conductive component having at least one selected from the group consisting of copper and silver, and an arc-proof component with a melting temperature of more than 1500.degree. C. In the contact electrode, a gradient A/X of a quantity of a composition component of the contact electrode on a surface or the contact electrode is 0.2-12 volume %/mm. Where, X1 is one point on the line of any radius R1 on the surface of the contact electrode, X2 is another point on the line of the radius R1 on the surface of the contact electrode, and X is a gap between the one point X1 and the another point X2 measured by mm, where X=X2-X1, and X2>X1 .gtoreq.0.
    Type: Grant
    Filed: March 7, 1996
    Date of Patent: March 10, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Tsuneyo Seki, Atsushi Yamamoto
  • Patent number: 5698008
    Abstract: A contact material for a vacuum valve including, a conductive constituent including at least copper, an arc-proof constituent including at least chromium and an auxiliary constituent including at least one selected from the group consisting of tungsten, molybdenum, tantalum and niobium. The contact material is manufactured by quench solidification of a composite body of the conductive constituent, the arc-proof constituent and the auxiliary constituent.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: December 16, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneyo Seki, Tsutomu Okutomi, Atsushi Yamamoto, Takashi Kusano
  • Patent number: 5687472
    Abstract: A method for manufacturing a vacuum interrupter including, a vacuum enclosure composed of an insulating tube sealed by metal flanges, a pair of electrodes in the vacuum enclosure which are able to make and break contact, and a pair of conducting shafts.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: November 18, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsutaka Honma, Hiromichi Somei, Tadahiro Aihara, Tsuneyo Seki, Atsushi Yamamoto
  • Patent number: 5500499
    Abstract: A contacts material for a vacuum valve including an arc-proof constituent including at least one selected from the group of chromium, titanium, zirconium, vanadium and yttrium, an auxiliary constituent including at least one selected from the group of tantalum, niobium, tungsten and molybdenum and a conductive constituent including at least one selected from the group of copper and silver. In the contacts material, an amount of the arc-proof constituent is from 10% to 70% by volume, a total amount of the arc-proof constituent together with the auxiliary constituent is not more than 75% by volume and an amount of the conductive constituent is the balance.
    Type: Grant
    Filed: January 13, 1994
    Date of Patent: March 19, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneyo Seki, Tsutomu Okutomi, Atsushi Yamamoto
  • Patent number: 5420384
    Abstract: A contact material for a vacuum interrupter includes: (a) from 25 to 70% by volume of a highly conductive component selected from the group consisting of Ag, Cu and combinations thereof, and (b) from 30 to 75% by volume of an arc-proof component comprising a carbide of an element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and combinations thereof, wherein the average grain size of the said arc-proof component is from 0.3 to 3 micrometers and the average grain distance of the arc-proof component is within the range of 0.1 to 1 micrometer. Contacts for a vacuum interrupter obtained from the contact material have improved wear resistance, large current interruption characteristic, wear resistance, and chopping characteristic, and low temperature rise characteristic.
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: May 30, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Atsushi Yamamoto, Tsuneyo Seki, Mikio Okawa, Mitsutaka Honma
  • Patent number: 5409519
    Abstract: A contacts material for a vacuum valve including an arc-proof constituent having at least one component selected from the group consisting of tantalum, niobium, tungsten and molybdenum and an auxiliary constituent having at least one component selected from the group consisting of chromium, titanium, yttrium, zirconium, cobalt and vanadium. The contact material further includes a conductive constituent having at least one component selected from the group consisting of copper and silver. The amount of the arc-proof constituent is from 25% to 75% by volume. The total amount of the arc-proof constituent together with the auxiliary constituent is no more than 75% by volume. The amount of the conductive constituent is the balance.
    Type: Grant
    Filed: May 28, 1993
    Date of Patent: April 25, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneyo Seki, Tsutomu Okutomi, Atsushi Yamamoto
  • Patent number: 5403543
    Abstract: Disclosed is a manufacturing process of an alloy material comprising a chromium component and a base component which comprises at least one element selected from tile group consisting of copper and silver, the manufacturing process comprising steps of: subjecting a chromium material with a carbon material to heat treatment; and manufacturing the alloy material using the chromium material treated at the heat treatment subjecting step and a raw material for tile base component. At the heat treatment subjecting step, the chromium material, mixed with 50 ppm to 5,000 ppm of the carbon material, is heated to a temperature within the range of 800.degree. C. to 1,400.degree. C. in a non-oxidizing atmosphere. According to this manufacturing process, the level of oxygen content in the alloy material are decreased to be not more than 200 ppm. The obtained alloy material can be used as a contact material for vacuum circuit breakers.
    Type: Grant
    Filed: June 3, 1992
    Date of Patent: April 4, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Tsuneyo Seki, Atsushi Yamamoto, Mikio Okawa, Tadaaki Sekiguchi, Yoshiko Majima
  • Patent number: 5354352
    Abstract: Disclosed is a contact material for vacuum circuit breakers and a manufacturing process thereof. The contact material includes a copper component, a chromium component and a bismuth component, and has a metallographic structure comprising: a first phase including the copper component and the bismuth component; and a second phase including the chromium component and interposed among the first phase. In this structure, the boundary surface between the first phase and the second phase appears in a structural cross section of the alloy composition as a substantially smooth boundary line, such that when a segment of the boundary line is defined by two arbitrary points which lie on the boundary line at a straight distance of 10 .mu.m, the ratio of the length of the segment to the straight distance of 10 .mu.m lies within a range of approximately 1.0 to 1.4.
    Type: Grant
    Filed: April 14, 1992
    Date of Patent: October 11, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneyo Seki, Tsutomu Okutomi, Atsushi Yamamoto, Mikio Okawa, Kiyofumi Otobe
  • Patent number: 5294761
    Abstract: A vacuum interrupter comprises a vacuum container which includes an insulation tube made of ceramics and having openings at both ends thereof, and sealing metals for hermetically sealing the openings respectively. In the vacuum container, a pair of contacts are disposed so that these contacts can detachably contact to each other. The composition of the material constituting at least one of the sealing metals comprises 25 to 55 wt % of Ni, 0.02 to 1.0 wt % of Si and substantially the residual amount of Cu. Preferably, the composition further comprises 0.02 to 1.5 wt % in total of Si and Mn and/or 5.0 wt % or less in total of Fe and Co.
    Type: Grant
    Filed: November 20, 1992
    Date of Patent: March 15, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Tsuneyo Seki, Hideo Suzuki, Shinzo Sugai, Kazuya Tujimoto, Hiroshi Watanabe, Kiyoshi Osabe, Atsushi Yamamoto, Hiroshi Yamazoe
  • Patent number: 5246512
    Abstract: The present invention relates to a contact for a vacuum interrupter obtained by processing a contact-forming material comprising from 20% to 60% by weight of Cr, Bi in an amount of from 0.05% to 1.0% by weight of the total amount of Cu and Bi, and the balance substantially Cu into the shape of a contact, and thereafter subjecting the processed material to vacuum heat treatment. The contact for the vacuum interrupter has both excellent anti-welding characteristics and excellent voltage withstanding characteristics.
    Type: Grant
    Filed: June 6, 1991
    Date of Patent: September 21, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneyo Seki, Tsutomu Okutomi, Atsushi Yamamoto, Kiyofumi Otobe, Tadaaki Sekiguchi
  • Patent number: 5149362
    Abstract: An Ag-Cu-WC contact forming material for a vacuum interrupter comprising a highly conductive component comprising Ag and Cu and an arc-proof component comprising WC wherein the content of the highly conductive component is such that the total amount of Ag and Cu(Ag+Cu) is from 25% to 65% by weight and the percentage of Ag based on the total amount of Ag and Cu[Ag/(Ag+Cu)] is from 40% to 80% by weight; wherein the content of the arc-proof component is from 35% to 75% by weight; wherein the structure of the highly conductive component comprises a matrix and a discontinuous phase, the discontinuous phase having a thickness or width of no more than 5 micrometers and wherein said arc-proof component comprises a discontinuous grain having a grain size of no more than 1 micrometer.
    Type: Grant
    Filed: July 28, 1989
    Date of Patent: September 22, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Atsushi Yamamoto, Seishi Chiba, Tsuneyo Seki, Mikio Okawa, Mitsutaka Honma, Kiyofumi Otobe, Yoshinari Satoh, Tadaaki Sekiguchi
  • Patent number: 5045281
    Abstract: A contact forming material for a vacuum interrupter comprising: from 25% to 65% by weight of a highly conductive component comprising Ag and Cu, and from 35% to 75% by weight of an arc-proof component selected from the group consisting of Ti, V, Cr, Zr, Mo, W and their carbides and borides, and mixtures thereof wherein the highly conductive component of the contact forming material comprises (i) a first highly conductive component region composed of a first discontinuous phase having a thickness or width of no more than 5 micrometers and a first matrix surrounding the first discontinuous phase, and (ii) a second highly conductive component region composed of a second discontinuous phase having a thickness or width of at least 5 micrometers and a second matrix surrounding the second discontinuous phase, wherein the first discontinuous phase in the first highly conductive component region is finely and uniformly dispersed in the first matrix at intervals of no more than 5 micrometers, and wherein the amount of
    Type: Grant
    Filed: February 27, 1990
    Date of Patent: September 3, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsutomu Okutomi, Mikio Okawa, Atsushi Yamamoto, Tsuneyo Seki, Yoshinari Satoh, Mitsutaka Honma, Seishi Chiba, Tadaaki Sekiguchi