Patents by Inventor Kei Tokumoto

Kei Tokumoto 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).

  • Publication number: 20090120155
    Abstract: Disclosed are a shaping tool and a method of using the shaping tool, capable of applying a sufficient compressive stress to a shaping member to prevent an excessively high tensile stress from being imposed on the shaping member so as to achieve an extended usable life even if the shaping member is made of a hard and brittle material. The shaping tool comprises a shaping member, a pressure-applying member surroundingly fitted onto the shaping member, a collet chuck surroundingly fitted onto the pressure-applying member, and a casing surroundingly fitted onto the collet chuck. The pressure-applying member has a plurality of outer peripheral slits and a plurality of inner peripheral slits, which are circumferentially arranged in alternate relation and at even intervals. The collet chuck has an externally-threaded portion at an upper or lower end thereof, and a taper surface formed in an outer peripheral surface thereof to have a diameter which gradually decreases toward the externally-threaded portion.
    Type: Application
    Filed: May 26, 2006
    Publication date: May 14, 2009
    Applicant: NIPPON TUNGSTEN CO., LTD.
    Inventors: Koki Minamoto, Kei Tokumoto, Shinji Goto, Makoto Funabiki
  • Patent number: 6279443
    Abstract: A die cut roll includes a rotary driving roll having projecting pressure cutting blades on a surface thereof formed in accordance with the shape of a product to be cut to thereby form a die cutter and an anvil roll adapted to receive an edge of each of the projecting pressure cutting blades of the die cutter. The rotary driving roll includes inclined finishing surfaces formed adjacent to a top smooth portion of an edge of each of the projecting pressure cutting blades by a grinding process so that the inclined finishing surfaces have grinding flaws which make an angle &phgr; of 50°-90° to ridgelines defining the top smooth portion.
    Type: Grant
    Filed: September 23, 1999
    Date of Patent: August 28, 2001
    Assignee: Nippon Tungsten Co., Ltd.
    Inventors: Kenji Nakahara, Koichi Ibusuki, Shouji Eguchi, Kohei Kitahara, Kei Tokumoto, Shigeya Sakaguchi
  • Patent number: 5545248
    Abstract: A titanium-base sintered alloy which comprises a TiC and/or TiN or Ti(C,N) solid solution accounting for 5 to 70 vol %, with the remainder being composed of two components. The first component is at least one species selected from the group consisting of Groups Va and VIa metallic elements, except Cr, or at least one species selected from the group consisting of carbides, nitrides, and carbonitrides of Groups Va and VIa metallic elements, except Cr. The second component is titanium. The first component accounts for 1 to 30 vol % and the second component accounts for 70 to 99 vol % of the total amount of the first and second components. The alloy produces a preferred result when the content of TiC or TiN is 35 to 70 vol % and the first component accounts for 1 to 15 vol % of the remainder. It is desirable that the TiC, TiN, and the first component of the remainder be in the form of a solid solution.
    Type: Grant
    Filed: February 14, 1995
    Date of Patent: August 13, 1996
    Assignee: Nippon Tungsten Co., Ltd.
    Inventors: Kei Tokumoto, Tetsunori Kitada, Hironobu Shinoaki, Shigeya Sakaguchi
  • Patent number: 4997192
    Abstract: A mechanical seal is, at a sliding surface and at its vicinty, formed of a pore-dispersed cemented carbide, so that the lubricating characteristics can be improved and the strength maintained by strictly stipulating the magnitude, shape, and volumetric ratio of the pores, such that pores are contained in an amount of 0.5 to 20 volume %, formed in at least one shape selected from the group of a substantialy spherical shape and a substantially cylindrical shape, the pores in the substantially spherical shape having an average diameter of 3 to 20 .mu.m, the pores in the substantially cylindrical shape having an average diameter of 3 to 20 .mu.m and an average length in the range from the average diameter up to 300 .mu.m, and that the pores are prevented from linking to each other to give a length greater than 2 mm.
    Type: Grant
    Filed: March 19, 1990
    Date of Patent: March 5, 1991
    Assignees: Tanken Seiko Kabushiki Kaisha, Nihon Tungsten Kabushiki Kaisha
    Inventors: Yataro Nagai, Mitsuyoshi Matsushita, Osamu Ishibashi, Kiyoshi Terasaki, Kei Tokumoto
  • Patent number: 4925490
    Abstract: A mechanical seal is, at a sliding surface and at its vicinity, formed of a pore-dispersed cemented carbide, so that the lubricating characteristics can be improved and the strength maintained by strictly stipulating the magnitude, shape, and volumetric ratio of the pores, such that pores are contained in an amount of 0.5 to 20 volume %, formed in at least one shape selected from the group of a substantially spherical shape and a substantially cylindrical shape, the pores in the substantially spherical shape having an average diameter of 3 to 20 .mu.m, the pores in the substantially cylindrical shape having an average diameter of 3 to 20 .mu.m and an average length in the range from the average diameter up to 300 .mu.m, and that the pores are prevented from linking to each other to give a length greater than 2 mm.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: May 15, 1990
    Assignees: Tanken Seiko Kabushiki Kaisha, Nihon Tungsten Kabushiki Kaisha
    Inventors: Yataro Nagai, Mitsuyoshi Matsushita, Osamu Ishibashi, Kiyoshi Terasaki, Kei Tokumoto