Patents by Inventor Harufumi Senno

Harufumi Senno 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: 5358576
    Abstract: In amorphous materials including at least one iron-transition metal of Fe, Co, and Ni, and at least one metalloid of B, C, Si, and P, excellent magnetic characteristics can be provided subject to the condition that 0.5 to 10 atomic % of the above-described iron-transition metals are substituted by Mn. In addition, when the amorphous material partially substituted with Mn as described above is further comprised of at least one element selected from Groups IIIa, IVa, Va, and VIa in the periodic table, the crystallization temperature is considerably raised.
    Type: Grant
    Filed: June 6, 1980
    Date of Patent: October 25, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Harufumi Senno, Hiroshi Sakakima, Masatsugu Yamaguchi, Eiichi Hirota
  • Patent number: 4590530
    Abstract: A magnetic head a core having a front core and a back core. The front core has a wear-resistant non-magnetic base and a soft magnetic thin film disposed on the base. The thin film is divided into halves by a magnetic gap therein. The back core has a U-shaped block of soft magnetic material and a wear-resistant non-magnetic member connected between the legs of the soft magnetic block. The front and back cores are coupled with each other with the thin film sandwiched therebetween, the magnetic gap in the thin film facing the wear-resistant non-magnetic member, and the soft magnetic thin film and the soft magnetic block being in face-to-face contact with each other out of the neighborhood of the magnetic gap to form a closed magnetic path across the magnetic gap.
    Type: Grant
    Filed: November 24, 1982
    Date of Patent: May 20, 1986
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Mitsuo Satomi, Yukihiro Yanagiuchi, Harufumi Senno
  • Patent number: 4578728
    Abstract: The invention provides a magnetic head having a core which includes a thin amorphous alloy film having a composition of Co.sub.a M.sub.b T.sub.c X.sub.d, for 70.ltoreq.a.ltoreq.95, 0.ltoreq.b.ltoreq.20, 3.ltoreq.c.ltoreq.20, 0.ltoreq.d<10, and a+b+c+d=100, where M is at least one metal selected from the group consisting of Fe, Ni, Cr, Mo, W and Mn, T is at least one metal selected from the group consisting of Ti, Zr, Hf, Nb and Ta, and X is at least one material selected from the group consisting of Si, B, C, Al and Ge; and a substrate having excellent resistance to wear and having the thin amorphous alloy film on a major surface thereof, wherein the thin amorphous alloy film is located at least in a portion adjacent a magnetic gap portion of the core which slidably contacts a magnetic recording medium is made of an amorphous alloy.
    Type: Grant
    Filed: November 30, 1982
    Date of Patent: March 25, 1986
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Mitsuo Satomi, Yukihiro Yanagiuchi, Harufumi Senno
  • Patent number: 4488195
    Abstract: A magnetic head and a method of producing same, wherein the magnetic head includes a head core formed of metallic magnetic material and has a head gap formed in a portion of the head core adapted to be positioned against a recording medium, and windings mounted on the head core. The material forming the head core is amorphous and has the following composition:(Co.sub.1-x M'.sub.x).sub.a Zr.sub.b Si.sub.c B.sub.d, where M' is at least one element selected from the group consisting of Cr, Mn, Fe Ni, Nb, Mo, W and Ti, 0.03.ltoreq.x.ltoreq.0.15, 3.ltoreq.b.ltoreq.25, 0.ltoreq.c.ltoreq.20, 0.ltoreq.d.ltoreq.5, and a+b+c+d=100.
    Type: Grant
    Filed: March 15, 1982
    Date of Patent: December 11, 1984
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yukihiro Yanagiuchi, Eiichi Hirota, Hiroshi Sakakima, Harufumi Senno
  • Patent number: 4437912
    Abstract: Amorphous alloy consisting mainly of 60-94 atomic % of at least one transition metal, and over 2 atomic % but below 20 atomic % of niobium. The amorphous alloys according to the invention are high in wear resistance and corrosion resistance and have a high saturated magnetic flux density and soft magnetic properties. The amorphous alloys have particular utility as core materials for magnetic heads.
    Type: Grant
    Filed: November 16, 1981
    Date of Patent: March 20, 1984
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Mitsuo Satomi, Harufumi Senno, Eiichi Hirota
  • Patent number: 4427462
    Abstract: High-silicon steel sheets or ribbons having the crystal texture described by (100)[011] are used for the fabrication of magnetic cores of electrical machinery in such a way that the easy axes of magnetization <001> coincide with the directions of magnetic circuits or lines of magnetic flux. Magnetic cores of, for instance, electric motors or transformers can be remarkably improved in efficiency.
    Type: Grant
    Filed: June 18, 1982
    Date of Patent: January 24, 1984
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Harufumi Senno, Masayuki Wakamiya, Yukio Horita
  • Patent number: 4312683
    Abstract: Amorphous alloy films are heat-treated in the presence of a magnetic field directed in a particular direction so as to suppress induced magnetic anisotropy in the film. The directed magnetic field includes a vertical magnetic field whose direction is perpendicular to the plane of the film, and a rotating magnetic field whose direction is being rapidly changed within a parallel plane with respect to the plane of the amorphous alloy film.
    Type: Grant
    Filed: September 5, 1980
    Date of Patent: January 26, 1982
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Harufumi Senno, Yukihiro Yanagiuchi, Eiichi Hirota
  • Patent number: 4288260
    Abstract: A method of heat treatments of amorphous alloy ribbons comprises the sequential steps of; grinding amorphous alloy ribbon continuously fed at a predetermined speed (V) selectively varied in the range of 1 cm/sec.ltoreq.V.ltoreq.50 cm/sec, to uniformly finish the ribbon, and successively, heat-treating the ribbon with its surface contacting a stationary or rotating heating body having a surface temperature (T) defined in the range of (T.sub.cry -200.degree. C.).ltoreq.V.ltoreq.(T.sub.cry +50.degree. C.), where T.sub.cry is a crystallization point temperature of the alloy, to uniformly enhance the magnetic properties of the ribbon, and to remove the specific curlings inherently caused by so-called splat cooling manufacturing method, without causing any developments of brittleness of the ribbon mentioned above.
    Type: Grant
    Filed: March 26, 1980
    Date of Patent: September 8, 1981
    Assignee: Matsushita Electric Industrial Co. Ltd.
    Inventors: Harufumi Senno, Hiroshi Sakakima, Yukihiro Yanagiuchi, Tsuneo Inoue, Masatsugu Yamaguchi, Eiichi Hirota
  • Patent number: 3947295
    Abstract: Bulk hardened magnetic materials with compositions expressed by a general formula Sm.sub.u Ce.sub.1.sub.-u (Co.sub.1.sub.-x.sub.-y Fe.sub.x Cu.sub.y).sub.z are provided. Compositions in the limited range of 0.3.ltoreq.u.ltoreq.1.0, 0.ltoreq.x.ltoreq.0.1, 0.09.ltoreq.y.ltoreq.0.18, 6.0.ltoreq.z.ltoreq.7.5 lead to magnetic materials with unexpectedly large maximum energy product and with a newly found two phase structure. Magnetic materials with maximum energy product of over 13 MG.sup.. Oe (megagauss) oersted), residual induction over 7000 G and intrinsic coercive force over 3000 Oe are obtained by subjecting the compositions to a sintering process.
    Type: Grant
    Filed: February 7, 1974
    Date of Patent: March 30, 1976
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshio Tawara, Harufumi Senno