Patents Assigned to Sumitomo Special Metals Co., Ltd.
  • Patent number: 5486756
    Abstract: A DC current sensor with an exciting core of soft magnetic material and formed with a pair of tubular bodies, each tubular body being positioned in parallel with the other to provide therebetween a space, through which passes a wire conducting a current to be detected; a detecting core formed with the side faces of a pair of tubular bodies and two plate-like members of soft magnetic material, each of which connecting integrally with each of the inside edges thereof near an opening of the tubular bodies to form a rectangular frame-shaped member as a whole; exciting coils, each of which magnetically energizing the exciting core in the direction perpendicular to the plane of the detecting core; detecting coils, each of which being wound around the detecting core; and applying an alternating current to the exciting coils to periodically and magnetically saturate the rectangular-shaped portions of the detecting core and exciting core, energizing the exciting coils to modulate a magnetic flux produced in the detect
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: January 23, 1996
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Makoto Kawakami, Shigeru Yamaguchi
  • Patent number: 5486224
    Abstract: To a fine R--Fe--B alloy powder comprised predominantly of 10-30 atomic % of R (wherein R stands for at least one element selected from rare earth elements including yttrium), 2-28 atomic % of B, and 65-82 atomic % of Fe in which up to 50 atomic % of Fe may be replaced by Co, at least one boric acid ester compound such as tributyl borate is added as a lubricant in a proportion of 0.01%-2% by weight and mixed uniformly before, during, or after fine grinding of the alloy powder. The resulting powder mixture is compacted by compression molding in a magnetic field and the green compacts are sintered and aged. Compression molding can be performed continuously without need of mold lubrication, and the resulting magnets have improved magnet properties with respect to residual flux density, maximum energy product, and intrinsic coercive force.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: January 23, 1996
    Assignees: Sumitomo Metal Industries, Ltd., Sumitomo Special Metals Co., Ltd.
    Inventors: Yoshihisa Kishimoto, Nobushige Hiraishi, Wataru Takahashi, Masakazu Ohkita, Naoyuki Ishigaki, Yutaka Matsuura
  • Patent number: 5475301
    Abstract: A DC current sensor using a continuous annularly-shaped detecting core of soft magnetic material; a continuous annularly-shaped exciting core of soft magnetic material intersecting with the detecting core perpendicular to the plane thereof; respective detecting and exciting coils wound respectively around the detecting and the exciting cores; an AC excitation of a given frequency applied to the exciting coil to saturate the detecting core; a wire conducting DC current to be detected extending through the detecting core to establish a magnetic flux therein; and a detector connected to the detecting coil for detecting the magnetic flux modulated by the AC excitation to detect the DC current flowing in the wire.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: December 12, 1995
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Makoto Kawakami, Shigeru Yamaguchi
  • Patent number: 5467769
    Abstract: A magnetic field generating apparatus has a permanent magnet arrangement for generating a magnetic field in a magnetic field generating space and a yoke arrangement for forming magnetic circuits for generation of the magnetic field together with the permanent magnet arrangement. The yoke arrangement includes a first pair of yokes arranged facing each other, a second pair of yokes arranged facing each other through which the first pair of yokes are magnetically connected to each other, a third pair of yokes arranged between one end of one of the first pair of yokes and one end of one of the second pair of yokes and between the other end of the one of the first pair of yokes and one end of the other of the second pair of yokes, respectively, and yoke moving units for independently moving the one of the first pair of yokes and each of the second pair of yokes with respect to the third pair of yokes, respectively.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: November 21, 1995
    Assignees: Hitachi Medical Corporation, Sumitomo Special Metals Co., Ltd.
    Inventors: Hitoshi Yoshino, Shigeo Hashimoto
  • Patent number: 5466308
    Abstract: Magnetic materials comprising Fe, B, R (rare earth elements) and Co having a major phase of Fe-Co-B-R intermetallic compound(s) of tetragonal systems and sintered anisotropic permanent magnets consisting essentially of, by atomic percent, 8-30% R (at least one of rare earth elements inclusive of Y), 2-28% B, no less than 50% Co, and the balance being Fe with impurities. Those may contain additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) providing Fe-Co-B-R-M type materials and magnets.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: November 14, 1995
    Assignee: Sumitomo Special Metals Co. Ltd.
    Inventors: Setsuo Fujimura, Yutaka Matsuura, Masato Sagawa
  • Patent number: 5465047
    Abstract: In a fixed polarized magnetic field generated by permanent magnets 10, a cylindrical cavity resonator 12 and a coil 14 modulating the magnetic field are provided. A micro-wave f generated from a micro-wave oscillator 16 is supplied through an isolator 18 and a subsequent attenuator 20 and then a circulator 24 to the cavity resonator. The oscillation output of a modulating frequency oscillator 42 is supplied to the coil 14. A movable end plate 60 is moved by a driving feature 58 to vary the resonance frequency f.sub.0 for a detection thereof and a subsequent negative feed back to a micro-wave oscillator 16 through a circuit comprising a low frequency amplifier 48, a phase detector 50, a low frequency oscillator 54, a phase shifter 56 and a micro-wave oscillator power source 52 thereby the micro-wave frequency f is so swept as to be maintained to be equal to the resonance frequency f.sub.0.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: November 7, 1995
    Assignees: Nikkiso Co., Ltd., Sumitomo Special Metals Co., Ltd.
    Inventors: Akio Nakanishi, Akira Furuse, Kazuo Nakagawa, Makoto Tsuneda, Atsushi Nukanobu
  • Patent number: 5432016
    Abstract: A material for a magnetic head slider consists essentially of 0.1 to 20.0 vol % of at least one of oxides the group Va elements of the International Periodic Table (Ta, Nb, V) and 80.0 to 99.9 vol % of stabilized cubic ZrO.sub.2 containing a stabilizer (Y.sub.2 O.sub.3, MgO, CeO.sub.2). It has improved precision machinability, machining efficiency, high strength, densified structure, affinity with the recording medium or lubricity, besides wear resistance. It may be machined precisely into a thin film magnetic head slider with a reduced amount of chipping.
    Type: Grant
    Filed: June 11, 1994
    Date of Patent: July 11, 1995
    Assignees: Sumitomo Special Metals Co., Ltd., Nippon Tungsten Co., Ltd.
    Inventors: Toshiaki Wada, Seiichi Hirao, Toyoshige Sasaki, Masaharu Shiroyama, Mitsuhiko Furukawa
  • Patent number: 5427734
    Abstract: The object of the invention is to provide a manufacturing method of a complex shaped R--Fe--B type sintered anisotropic magnet improved the moldability of injection molding and preventing the reaction between R ingredients and binder and controlled the degradation of magnetic characteristics due to residual carbon and oxygen. Utilizing the R--Fe--B type alloy powder or the resin coated said alloy powder, and methylcellulose and/or agar and water, instead of the usual thermoplastic binder, it is mixed and injection molded. The molded body is dehydrated by the freeze vacuum dry method to control the reaction between R ingredients and of the R--Fe--B alloy powder and water; furthermore, by administering the de-binder treatment in the hydrogen atmosphere, and sintering it after the dehydrogen treatment, residual oxygen and carbon in the R--Fe--B sintered body is drastically reduced, improving the moldability during the injection molding to obtain a three dimensionally complex shape sintered magnet.
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: June 27, 1995
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Osamu Yamashita, Masahiro Asano, Tsunekazu Saigo
  • Patent number: 5425818
    Abstract: A densified high performance rare earth-iron-nitrogen permanent magnet obtained from a powder of a Th.sub.2 Zn.sub.17 compound containing nitrogen at interlattice sites, without using autogeneous sintering and yet preventing decomposition and/or denitrification from occurring. The process for producing the same need not necessarily use a binder, and it comprises compaction molding, or charging while applying a magnetic field, a powder of a nitrogen intrusion T--R--N compound having a specified composition and a Th.sub.2 Zn.sub.17 crystal structure, and applying thereto shock compression at a drive pressure of from 10 to 25 GPa as reduced to an equivalent drive pressure in an iron capsule.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: June 20, 1995
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Satoshi Hirosawa, Takashi Ikegami, Ken Makita, Tsutomu Mashimo
  • Patent number: 5389878
    Abstract: The invention provides an electron spin resonance device in which a measuring sample is arranged in a cavity resonator in a polarization magnetic field for a receipt of a predetermined microwave power and a subsequent resonance signal detection from said sample. A microwave signal amplifier is arranged on a prestage of a microwave detection circuit for an addition of a part of an output from a microwave oscillator at an input terminal of said amplifier so as to accomplish a balanced cancellation of a microwave reflective power from said cavity resonator.
    Type: Grant
    Filed: April 22, 1993
    Date of Patent: February 14, 1995
    Assignees: Nikkiso Co., Ltd., Sumitomo Special Metals Co., Ltd.
    Inventors: Kazuo Nakagawa, Makoto Tsuneda, Atsushi Nukanobu, Akio Nakanishi, Akira Furuse
  • Patent number: 5387356
    Abstract: It is an object of the present invention to provide a process of producing calcined materials for ferrite magnet, whereby foreign phase produced in calcined powders is eliminated and the ferrite magnet having a superior magnetic properties is obtained easily. Since mill scales roughly milled into a mean particle size of 20 .mu.m or less is subjected to primary oxidation treatment to change its oxidation percentage 95% or higher, and oxidized completely by secondary oxidation treatment in an inclined rotary kiln up to 700.degree. C. in an atmosphere containing O.sub.2 content of 8% to 10% at a charging side of raw material, foreign phase is not produced in the calcined powders during ferrite formation at high temperatures, and the ferrite magnet having a superior magnetic properties can be obtained.
    Type: Grant
    Filed: March 30, 1994
    Date of Patent: February 7, 1995
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventor: Atsushi Hamamura
  • Patent number: 5387291
    Abstract: A process for producing a starting powder material for use in the fabrication of high performance R--Fe--B permanent magnets comprising an R.sub.2 Fe.sub.14 B compound as the principal phase, which is characterized by adding 70% by weight or less of a specified alloy powder for adjusting the composition comprising an R.sub.2 Fe.sub.17 compound to a specified principal phase R--Fe--B alloy powder comprising an R.sub.2 Fe.sub.14 B compound as the principal phase. This process enables production of a starting alloy powder material considerably reduced in contents of the unfavorable B-rich and R-rich phases which impair the magnetic properties of the final magnet, because the starting powder blend allows the B-rich and R-rich compounds in the principal phase alloy powder to react with the R.sub.2 Fe.sub.17 compound being incorporated in the alloy powder for adjusting the composition.
    Type: Grant
    Filed: March 17, 1993
    Date of Patent: February 7, 1995
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Yuji Kaneko, Koki Tokuhara
  • Patent number: 5384538
    Abstract: An improved magnetic field generating device for use with a medical nuclear magnetic resonance tomographic device (MRI). The device comprises a magnetic circuit formed of a pair of magnetic pole pieces connected by yoke members in opposite relationship with each other leaving a space sufficient to accommodate therebetween an object receiving a medical inspection. According to the present invention, a super-conductive coil is wound around one of the pairs of magnetic pole pieces and the dimensional relationship between the two magnetic pole pieces is varied in a variety of ways to reduce the magnetic field imbalance, with the advantages that the magnetic flux distribution becomes highly uniform throughout the space between the pair of magnetic pole pieces, the patient entering the space has no oppressive sensation and the manufacturing cost can be reduced to a considerable degree.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: January 24, 1995
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Kimiharu Ohta, Masahiro Yuki
  • Patent number: 5358795
    Abstract: This invention provides heat-conductive materials which may receive evenly the heat as applied thereto, which have an improved heat-releasing effect, which are free from fine pores on the surfaces thereof and therefore have excellent adhesiveness to thin films of plating materials or brazing materials, which have excellent compatibility with materials to be applied thereto, such as chips or sealant resins, with respect to the thermal expansion coefficients of them, and have excellent thermal conductivity, and which may have any desired thermal expansion coefficient and thermal conductivity in accordance with the use and object of them. It also provides methods of producing the heat-conductive materials.
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: October 25, 1994
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Yasuyuki Nakamura, Makoto Kawakami
  • Patent number: 5355017
    Abstract: In a lead frame material made of a strip of copper or copper alloy sheet for use in resin packages in which semiconductor chips are mounted to and resin-sealed in island portions of a lead frame fabricated from a strip of substrate material, the lead frame material includes selective spot-clad material in which metal foils of low thermal expansion, each of a predetermined size, are roll-bonded and arranged at a predetermined interval to respective positions to be formed with island portions in the longitudinal direction of the substrate material, either on the surface where the semiconductor chips are not to be mounted or on both the surface where the semiconductor chips are to be mounted and on the opposite side. Damage to the chips such as warping or peeling can be prevented during heating upon mounting them.
    Type: Grant
    Filed: November 20, 1992
    Date of Patent: October 11, 1994
    Assignee: Sumitomo Special Metal Co. Ltd.
    Inventors: Yasuyuki Nakamura, Shin Nemoto
  • Patent number: 5316595
    Abstract: Fe-B-R type permanent magnet is produced by: forming an anticorrosive coating film layer on a Fe-B-R base permanent magnet material body by means of vapor deposition to thereby improve the corrosion resistance thereof.The anticorrosive thin film is formed of metal, oxides, nitrides, carbides, borides, silicides, composite compositions thereof, or a mixture thereof. Additionally blasting, shot peening, heat treatment for forming an interdiffusion layer, and/or resin impregnation may be applied.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: May 31, 1994
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Takaki Hamada, Tetsuji Hayakawa, Yutaka Matsuura
  • Patent number: 5302560
    Abstract: A sintered material for recording/reading (particularly magnetic) head slider is produced by:preparing a powdery mixture which comprises 0.5 to 6.0% by weight of at least one component selected from the component group A consisting of the following elements and compounds thereof, a garnet type compound consisting essentially of erbium oxide and aluminum oxide in amounts of 2 to 12% by weight and 0 (exclusive) to 2 (inclusive) % by weight based on the total composition, respectively, and expressed by the formula Er.sub.3 (Al,Er).sub.2 (AlO.sub.4).sub.3 through (Er, Al).sub.3 Al.sub.2 (AlO.sub.4).sub.3, and the balance being silicon carbide powder:the elements for the component group A being Ti, V, Cr, Mn, Mg, Y, Zr, Nb, Mo, Ba, La, Ce, Gd, Hf, Ta, W, Th, and Cs; andsintering the resultant mass under the application of a high pressure.Further sintering aids of Be, BeO, B and B.sub.4 C may be present. For the garnet type compound, erbium oxide may be used, preferably in combination with alumina.
    Type: Grant
    Filed: January 8, 1992
    Date of Patent: April 12, 1994
    Assignees: Sumitomo Special Metals Co., Ltd., Nippon Tungsten Co., Ltd.
    Inventors: Toshiaki Wada, Yoshiaki Katsuyama, Mitsuhiko Furukawa, Takashi Kitahira, Michito Miyahara, Kiyohito Misumi, Masaharu Shiroyama
  • Patent number: 5300809
    Abstract: A heat-conductive composite material usable as a substrate (heat sink) for mounting a semiconductor thereon or a lead frame includes which comprises a core sheet and metal foil layers welded to the both surfaces of the core sheet. The core sheet is composed of a metal sheet of high thermal expansion sandwiched between two metal sheets of low thermal expansion, each having a number of through-holes in the direction of the thickness, and the three layers are laminated and integrated so that a part of the metal sheet of high thermal expansion is exposed out to the metal surfaces of low thermal expansion through the through-holes of the metal sheets of low thermal expansion The metal foil layers each are made of a metal of high thermal expansion, which are same as or different from the metal of high thermal expansion of constituting the core sheet.
    Type: Grant
    Filed: June 1, 1993
    Date of Patent: April 5, 1994
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Yasuyuki Nakamura, Kenji Hirano, Makoto Kawakami
  • Patent number: 5295296
    Abstract: The invention is concerned with a method and an apparatus for working a clad material used as a reed frame for a flat package type integrated circuit. When metal foils of a predetermined size is superimposed at a predetermined position on a strip-like material, press contacted and rolled to produce a continuous clad material, and reference holes are bored in the clad material, not only the relative position between the reference holes but also the relative position between the reference holes and the metal foils previously applied to the clad material may be set accurately. Even if the pitch distances between the reference holes provided in the clad material differ from one another, press working by the metal mold may be continuously performed using these reference holes.
    Type: Grant
    Filed: August 27, 1992
    Date of Patent: March 22, 1994
    Assignees: Citizen Watch Co., Ltd., Sumitomo Special Metals Co., Ltd.
    Inventors: Katsumi Hagiwara, Akihiro Tanaka, Kou Sasaki, Kiyohito Nagasawa, Shin Nemoto, Kazuhiro Yamamoto
  • Patent number: 5283544
    Abstract: A magnetic field generating device used for MRI includes a pair of magnetic pole pieces to each other to provide a gap therebetween and generate a magnetic field in the gap, the magnetic pole pieces being formed by laminating and integrating a plurality of non-oriented silicon steel sheets. By using laminated non-oriented silicon sheets the eddy current generated in the magnetic pole pieces caused by the application of GC pulses can be reduced and phenomenon of the residual magnetism can also be reduced.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: February 1, 1994
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Hideya Sakurai, Masaaki Aoki