Patents by Inventor Takao Sawa
Takao Sawa 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).
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Patent number: 6475302Abstract: Disclosed is a permanent magnet which comprises an alloy containing a hard magnetic phase having a ThMn12 type tetragonal structure and a nonmagnetic phase. The alloy is represented by a general formula given below: [R1-a(M1)a][T1-b-c(M2)b(M3)c]dx&agr; where R is at least one rare earth element (including Y), Ml is at least one element selected from the group consisting of Zr and Hf, T is at least one element selected from the group consisting of Fe, Co and Ni, M2 is at least one element selected from the group consisting of Cu, Bi, Sn, Mg, In and Pb, M3 is at least one element selected from the group consisting of Al, Ga, Ge, Zn, B, P and S, X is at least one element selected from the group consisting of Si, Ti, V, Cr, Mn, Nb, Mo, Ta and W, and the atomic ratios of a, b, c, d and &agr; fall within the ranges of 0≦a≦0.6, 0.01≦b≦0.20, 0≦c≦0.05, 6≦d≦11, and 0.5≦&agr;≦2.0.Type: GrantFiled: December 28, 2000Date of Patent: November 5, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Wu Mei, Toshiya Sakamoto, Shinya Sakurada, Takao Sawa, Akihiko Tsutai, Akiko Saito, Masashi Sahashi
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Publication number: 20020036558Abstract: A bond magnet comprises a molded body in which a mixture of flake of magnet material comprising rare earth element-iron-nitrogen as main component, TbCu7 type crystal phase as a principal phase and a thickness of less than 200 &mgr;m a binder is compression molded. A compression molded body constituting a bond magnet has a density of 6×103 kg/m3 or more. In the step of compression molding a mixture of magnet material and binder, pressure is applied a plurality of times, or pressure is applied while rotating a punch and die, or the binder is cured while applying pressure to obtain such a bond magnet with good reproducibility. Such a bond magnet has excellent magnetic properties and corrosion resistance.Type: ApplicationFiled: August 22, 2001Publication date: March 28, 2002Inventors: Katsutoshi Nakagawa, Fumiyuki Kawashima, Takao Sawa, Shinya Sakurada, Tomohisa Arai
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Patent number: 6317020Abstract: A bond magnet comprises a molded body in which a mixture of flake of magnet material comprising rare earth element-iron-nitrogen as main component, TbCu7 type crystal phase as a principal phase and a thickness of less than 200 &mgr;m a binder is compression molded. A compression molded body constituting a bond magnet has a density of 6×103 kg/m3 or more. In the step of compression molding a mixture of magnet material and binder, pressure is applied a plurality of times, or pressure is applied while rotating a punch and die, or the binder is cured while applying pressure to obtain such a bond magnet with good reproducibility. Such a bond magnet has excellent magnetic properties and corrosion resistance.Type: GrantFiled: May 19, 2000Date of Patent: November 13, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Katsutoshi Nakagawa, Fumiyuki Kawashima, Takao Sawa, Shinya Sakurada, Tomohisa Arai
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Publication number: 20010031373Abstract: A soft magnetic alloy fiber has a width of 10 &mgr;m or more to less than 500 &mgr;m, a thickness of 2 &mgr;m or more to less than 20 &mgr;m, and a Curie temperature of −50° C. or higher.Type: ApplicationFiled: March 9, 2001Publication date: October 18, 2001Inventors: Takao Sawa, Katsutoshi Nakagawa, Hisashi Takahashi, Teruo Murakami, Masao Obama
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Publication number: 20010022259Abstract: The magnetic powder for validity determining ink is composed of magnetic oxide powder having a Curie temperature between −50° C. and 150° C. and a mean powder particle diameter of 10 &mgr;m or less.Type: ApplicationFiled: March 9, 2001Publication date: September 20, 2001Inventors: Takao Sawa, Katsutoshi Nakagawa, Teruo Murakami, Tadahiko Kobayashi, Hisashi Takahashi, Masao Obama
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Publication number: 20010020495Abstract: Disclosed is a permanent magnet which comprises an alloy containing a hard magnetic phase having a ThMn12 type tetragonal structure and a nonmagnetic phase.Type: ApplicationFiled: December 28, 2000Publication date: September 13, 2001Inventors: Wu Mei, Toshiya Sakamoto, Shinya Sakurada, Takao Sawa, Akihiko Tsutai, Akiko Saito, Masashi Sahashi
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Patent number: 6130006Abstract: There is provided a hydrogen-absorbing alloy which contains an alloy ingot manufactured by means of a casting or sintering method or a pulverized product of the alloy ingot, and the alloy ingot being represented by the following general formula (1),(Mg.sub.1-a-b R1.sub.a M1.sub.b)Ni.sub.z (1)wherein R1 is at least one element selected from rare earth elements (including Y), M1 is at least one element selected from elements having a larger electronegativity than that of Mg (excluding the elements of R1, Cr, Mn, Fe, Co, Cu, Zn and Ni), and a, b and z are respectively a number satisfying conditions 0.1.ltoreq.a.ltoreq.0.8, 0<b.ltoreq.0.9, 1-a-b>0, and 3.ltoreq.z.ltoreq.3.8.Type: GrantFiled: June 16, 1998Date of Patent: October 10, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Tatsuoki Kohno, Isao Sakai, Masaaki Yamamoto, Motoya Kanda, Hideki Yoshida, Fumiyuki Kawashima, Takao Sawa, Takamichi Inaba, Shusuke Inada, Hirotaka Hayashida, Hiroshi Kitayama
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Patent number: 6030724Abstract: A hydrogen-storage alloy containing as a component element thereof an element easily reactive with hydrogen to be selected from among the elements of Group 1A, Group 1A, Group 3A, Group 4A, and Group 4A in the Periodic Table of the Elements and having a quasi-crystalline phase as at least part of the component phases thereof. The quasi-crystalline phase has an element of axial rotation selected from among 5-fold, 8-fold, 10-fold, and 12-fold symmetric axis. The hydrogen-storage alloy exhibits outstanding resistance to corrosion, permits effective prevention of comminution, and further excels in terms of the abundance of hydrogen to be absorbed and released.Type: GrantFiled: August 2, 1996Date of Patent: February 29, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Takao Sawa, Takamichi Inaba, Yumiko Takahashi
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Patent number: 5843372Abstract: A hydrogen-absorbing alloy for battery according to the present invention comprises an alloy having the composition represented by a general formula A Ni.sub.a Mn.sub.b M.sub.c ?where, A is at least one kind of element selected from rare earth elements including Y (yttrium), M is a metal mainly composed of at least one kind of element selected from Co, Al, Fe, Si, Cr, Cu, Ti, Zr, Zn, Hf, V, Nb, Ta, Mo, W, Ag, Pd, B, Ga, In, Ge and Sn, 3.5.ltoreq.a.ltoreq.5, 0.1.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.1, 4.5.ltoreq.a+b+c.ltoreq.6!, wherein the alloy has columnar structures in which the area ratio of the columnar structures having the ratio of a minor diameter to a major diameter (aspect ratio) of 1:2 or higher is 50% or more. Further, an average minor diameter of the columnar structures is set to 30 microns or less.Type: GrantFiled: December 17, 1996Date of Patent: December 1, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyuki Hasebe, Shusuke Inada, Yoshiyuki Isozaki, Takamichi Inaba, Takao Sawa, Hiromichi Horie, Noriaki Yagi, Hiromi Shizu, Yoshiko Kanazawa
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Patent number: 5804282Abstract: A magnetic core is obtained by winding or laminating at least one alloy ribbon and has excellent squareness characteristic and magnetic saturation characteristic in a high frequency region wherein the squareness ratio of the magnetic core is improved by restricting the surface roughness of the alloy ribbon to specific regions.Type: GrantFiled: November 20, 1996Date of Patent: September 8, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Yumie Watanabe, Yumiko Takahashi, Takao Sawa, Yoshiyuki Yamaguchi, Susumu Matsushita, Masami Okamura
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Patent number: 5753386Abstract: There is provided a hydrogen-absorbing alloy for battery comprising a rapidly-quenched alloy having the composition represented by a general formula ANi.sub.a M.sub.b M'.sub.c T.sub.d (where, A is composed of La, Ce, Pr, Nd and Y, an amount of La content in A is 50-99 wt %, an amount of Ce content is 1-30 wt %, an amount of Pr content is 0-10 wt %, an amount of Nd content is 0-10 wt % and an amount of Y content is 0-10 wt %; M is at least one element selected from Co, Fe and Cu; M' is at least one element selected from Mn and Al; T is at least one element selected from B, Si, S, Cr, Ga, Ge, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Bi, P, V, Nb, Ta and W; and a, b, c and d are atomic ratios and satisfy 3.2.ltoreq.a.ltoreq.4.0, 0.4.ltoreq.b.ltoreq.1.0, 0.3.ltoreq.c.ltoreq.0.8, 0.ltoreq.d.ltoreq.0.2, 4.9.ltoreq.a+b+c+d.ltoreq.5.4), characterized in that a hydrogen equilibrium pressure when the number of hydrogen atoms absorbed by one atom of the alloy at a temperature of 60.degree. C. is 0.4 is 0.05-0.6 atm.Type: GrantFiled: September 26, 1996Date of Patent: May 19, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Takamichi Inaba, Takao Sawa, Shusuke Inada, Fumiyuki Kawashima, Noriaki Sato, Toshiya Sakamoto, Masami Okamura, Tomohisa Arai, Keisuke Hashimoto
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Patent number: 5654115Abstract: A hydrogen-absorbing alloy for battery according to the present invention comprises an alloy having the composition represented by a general formula A Ni.sub.a Mn.sub.b M.sub.c [where, A is at least one kind of element selected from rare earth elements including Y (yttrium), M is a metal mainly composed of at least one kind of element selected from Co, Al, Fe, Si, Cr, Cu, Ti, Zr, Zn, Hf, V, Nb, Ta, Mo, W, Ag, Pd, B, Ga, In, Ge and Sn, 3.5.ltoreq.a.ltoreq.5, 0.1.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.1, 4.5.ltoreq.a+b+c.ltoreq.6], wherein the alloy has columnar structures in which the area ratio of the columnar structures having the ratio of a minor diameter to a major diameter (aspect ratio) of 1:2 or higher is 50% or more. Further, an average minor diameter of the columnar structures is set to 30 microns or less.Type: GrantFiled: May 30, 1995Date of Patent: August 5, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyuki Hasebe, Shusuke Inada, Yoshiyuki Isozaki, Takamichi Inaba, Takao Sawa, Hiromichi Horie, Noriaki Yagi, Hiromi Shizu, Yoshiko Kanazawa
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Patent number: 5622768Abstract: A magnetic core is obtained by winding or laminating at least one alloy ribbon and has excellent squareness characteristic and magnetic saturation characteristic in a high frequency region wherein the squareness ratio of the magnetic core is improved by restricting the surface roughness of the alloy ribbon to specific regions.Type: GrantFiled: May 4, 1994Date of Patent: April 22, 1997Assignee: Kabushiki Kaishi ToshibaInventors: Yumie Watanabe, Yumiko Takahashi, Takao Sawa, Yoshiyuki Yamauchi, Susumu Matsushita, Masami Okamura
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Patent number: 5522948Abstract: An Fe-based soft magnetic alloy is consisted essentially of fine crystal grains constituting 50% or more of the alloy structure by area %. The Fe-based soft magnetic alloy has the composition substantially represented by the general formula: Fe.sub.100-a-b-c-d-e-f X.sub.a M.sub.b M'.sub.c A.sub.d Si.sub.e Z.sub.f (wherein X is at least one compound selected from the ceramic materials fusible when the composition is fused and rapidly quenched to form a rapidly cooled alloy, M is at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, M' is at least one element selected from the group consisting of Mn, elements in the platinum group, Ag, Au, Zn, Al, Ga, In, Sn, Cu and rare each elements, A is at least one element selected from among Co and Ni, Z is at least one element selected from the group consisting of B, C, P and Ge. Said a, b, c, d, e and f respectively satisfy 0.1.ltoreq.a.ltoreq.5, 0.1.ltoreq.b.ltoreq.10, 0.ltoreq.c.ltoreq.10, 0.ltoreq.d.ltoreq.40, 5.ltoreq.e.Type: GrantFiled: March 24, 1994Date of Patent: June 4, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Takao Sawa, Yumiko Takahashi
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Patent number: 5470646Abstract: A magnetic core comprises a ferroalloy amorphous film and an insulator layer. The preferable ferroalloy amorphous film is defined as follows:(Fe.sub.1-x T.sub.x).sub.100-y X.sub.ywherein:T is at least one element selected from Co and Ni;X is at least one element selected from Si, B, P, C andGe; and0<x.ltoreq.0.414.ltoreq.y.ltoreq.21The preferable insulator layer is made of a high polymer film, for example a polyester film. Also, the magnetic core has the magnetic characteristics of the direct current coercive force is 0.2 Oe or less, and total value of residual magnetic flux density and saturated magnetic flux density is 27 KG or more.Type: GrantFiled: April 4, 1994Date of Patent: November 28, 1995Assignee: Kabushiki Kaisha ToshibaInventors: Masami Okamura, Takao Sawa, Yoshiyuki Yamauchi, Takao Kusada
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Patent number: 5334262Abstract: A method is disclosed for producing an extremely thin soft magnetic alloy strip, in which a molten alloy is ejected through a nozzle onto the surface of a rotating cooling member and rapidly quenched. The length of the short side of the rectangular nozzle, the distance between the nozzle and the rotating cooling member, peripheral speed of the rotating cooling member, ejecting pressure of the molten alloy, and atmosphere pressure of ejecting are specified.Type: GrantFiled: December 10, 1992Date of Patent: August 2, 1994Assignees: Kabushiki Kaisha Toshiba, Masaaki YagiInventors: Takao Sawa, Masaaki Yagi
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Patent number: 5258681Abstract: A magnetic slot wedge inserted in each slot of a stator core of a dynamo-electric machine so as to close an opening of each slot for preventing coils embedded in each slot from getting out of each slot is disclosed. The slot wedge includes a first thin non-magnetic sheet such as a polyester film having the thickness of several ten microns or an aromatic aramid paper, an amorphous sheet bonded to one of two faces of the first non-magnetic sheet opposite the other face facing a coil side in the condition that the wedge is inserted in each slot, and a second thin non-magnetic sheet bonded to the amorphous sheet so as to cover it. Each non-magnetic sheet has such dimensions that each non-magnetic sheet is projected from both ends and both side edges of the amorphous sheet.Type: GrantFiled: March 25, 1993Date of Patent: November 2, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Sadayoshi Hibino, Tadayuki Sato, Motoyasu Mochizuki, Tadatomo Kimura, Shigeo Ozawa, Takao Sawa, Yasuo Sakata
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Patent number: 5252877Abstract: A slot insulating magnetic wedge inserted into the vicinity of the center of an opening portion of a stator slot, the slot insulating magnetic wedge being contacted with an inner surface of the stator slot of a motor. The slot insulating magnetic wedge comprises a non-magnetic insulating thin leaf shaped material and a magnetic material layer laminated on at least one surface of the non-magnetic insulating thin leaf shaped material, the electric resistance of the magnetic material layer being in the range from 10 .mu..OMEGA..cm to 200 .mu..OMEGA..cm. The magnetic material layer comprises an amorphous magnetic alloy thin film, a Fe-based magnetic alloy thin ribbon having ultra fine crystalline particles, a crystalline magnetic alloy thin ribbon, a crystalline or amorphous magnetic alloy thin film produced by thin film forming technologies, or the like. The magnetic material layer with the electric resistance in the range from 10 .mu..OMEGA..cm to 200 .mu..OMEGA..Type: GrantFiled: December 13, 1991Date of Patent: October 12, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Takao Sawa, Yasuo Sakata, Sadayoshi Hibino, Tadayuki Sato, Motoyasu Mochizuki, Tadatomo Kimura, Shigeo Ozawa
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Patent number: 5225006Abstract: Fe-based soft magnetic alloy having excellent soft magnetic characteristics with high saturated magnetic flux density, characterized in that it has fine crystal grains and is expressed by the general formula:Fe.sub.100-a-b-c-d M.sub.a M'.sub.b Y.sub.c N.sub.dwhere M is at one or more selected from Cu, Ag, Au, Zn, Sn, Pb, Sb, and Bi;M' is at least one or more selected from the elements of Groups IVa, Va, VIa of the periodic table, or Mn, Co, Ni, and Al,Y is at least one or more selected from Si, P, or B, and wherein "a", "b", "c" and "d" expressed in at. % are as follows:0.01.ltoreq.a.ltoreq.50.1.ltoreq.b.ltoreq.1015.ltoreq.c.ltoreq.280<d.ltoreq.8.A method is also provided treating the alloy to segregate fine crystal grains. The method involves heat treating the alloy for from one minute to ten hours at a temperature of from 50.degree. C. below to 120.degree. C. above the crystallization temperature of said alloy.Type: GrantFiled: June 11, 1991Date of Patent: July 6, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Takao Sawa, Masami Okamura
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Patent number: 5198040Abstract: In the production by the single-roll technique of a thin amorphous strip as the matrix for the manufacture of a thin Co-based amorphous alloy strip or a thin Fe-based microcrystalline alloy strip, the conditions for the production are controlled to those specified by the invention. The production conditions thus controlled concern the atmosphere and the pressure to be used for ejecting a molten metal onto a rotating cooling member, the shape of a nozzle, the distance between the nozzle and the rotary cooling member, the material for the rotary cooling member and peripheral speed of the rotary cooling member, etc. The individual numerical values of these conditions are severally important. The thin strip which has an extremely small thickness and few pinholes thus is obtained. In the thin Co-based amorphous alloy strip, the extreme decrease of thickness to below 4.8 .mu.m notably enhances the soft magnetic properties such as permeability and core loss in the high frequency range.Type: GrantFiled: December 11, 1991Date of Patent: March 30, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Takao Sawa, Masaaki Yagi