Patents by Inventor Akiyasu Oota

Akiyasu Oota 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: 6743394
    Abstract: A case according to the present invention is used in a sintering process to produce a rare-earth magnet. The case includes: a body with an opening; a door for opening or closing the opening of the body; and supporting rods for horizontally sliding a sintering plate, on which green compacts of rare-earth magnetic alloy powder are placed. The supporting rods are secured inside the body. At least the body and the door are made of molybdenum.
    Type: Grant
    Filed: June 19, 2002
    Date of Patent: June 1, 2004
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Akiyasu Oota, Tsuyoshi Wada, Katsumi Okayama
  • Patent number: 6736343
    Abstract: A milling apparatus comprises a mill for milling of an object material such as a rare-earth alloy. The mill includes a mill main body. A classifying rotor for classification of a powder is provided inside and at an upper portion of the mill main body. The mill main body has an outer circumference provided with three leg portions spaced equally from each other. Each of the leg portions supports the mill main body at a position above the center of gravity of the mill. Each of the leg portions is provided with a weight detector for detection of a weight of the mill holding the object material remaining in the mill. A flexible pipe is provided between the mill and a raw material feeder for supply of the object material to the mill. Another flexible pipe is provided between the mill and a collecting tank for collection of the powder.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: May 18, 2004
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Akiyasu Oota, Akihito Tsujimoto, Katsumi Okayama
  • Patent number: 6696015
    Abstract: The method for producing a rare-earth sintered magnet of the present invention includes the steps of: compacting alloy powder for the rare-earth sintered magnet to form a green compact; loading the green compact into a case having a structure restricting a path through which gas flows between the outside and inside of the case, and placing a gas absorbent at least near the path; and sintering the green compact by heating the case including the green compact inside in a decompressed atmosphere.
    Type: Grant
    Filed: May 2, 2001
    Date of Patent: February 24, 2004
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Koki Tokuhara, Akiyasu Oota, Tsuyoshi Wada, Katsumi Okayama, Tomoiku Ohtani, Kunitoshi Kanno
  • Publication number: 20020197180
    Abstract: A green compact of a rare earth alloy magnetic powder is made by pressing the powder. The powder is pressed within an air environment that has a temperature controlled at 30° C. or less and a relative humidity controlled at 65% or less.
    Type: Application
    Filed: August 21, 2002
    Publication date: December 26, 2002
    Applicant: SUMITOMO SPECIAL METALS CO., LTD.
    Inventors: Koki Tokuhara, Shuhei Okumura, Akiyasu Oota
  • Publication number: 20020166908
    Abstract: A milling apparatus comprises a mill for milling of an object material such as a rare-earth alloy. The mill includes a mill main body. A classifying rotor for classification of a powder is provided inside and at an upper portion of the mill main body. The mill main body has an outer circumference provided with three leg portions spaced equally from each other. Each of the leg portions supports the mill main body at a position above the center of gravity of the mill. Each of the leg portions is provided with a weight detector for detection of a weight of the mill holding the object material remaining in the mill. A flexible pipe is provided between the mill and a raw material feeder for supply of the object material to the mill. Another flexible pipe is provided between the mill and a collecting tank for collection of the powder.
    Type: Application
    Filed: July 9, 2002
    Publication date: November 14, 2002
    Applicant: Sumitomo Special Metals Co. Ltd.
    Inventors: Akiyasu Oota, Akihito Tsujimoto, Katsumi Okayama
  • Patent number: 6474576
    Abstract: A milling apparatus comprises a mill for milling of an object material such as a rare-earth alloy. The mill includes a mill main body. A classifying rotor for classification of a powder is provided inside and at an upper portion of the mill main body. The mill main body has an outer circumference provided with three leg portions spaced equally from each other. Each of the leg portions supports the mill main body at a position above the center of gravity of the mill. Each of the leg portions is provided with a weight detector for detection of a weight of the mill holding the object material remaining in the mill. A flexible pipe is provided between the mill and a raw material feeder for supply of the object material to the mill. Another flexible pipe is provided between the mill and a collecting tank for collection of the powder.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: November 5, 2002
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Akiyasu Oota, Akihito Tsujimoto, Katsumi Okayama
  • Publication number: 20020159909
    Abstract: A case according to the present invention is used in a sintering process to produce a rare-earth magnet. The case includes: a body with an opening; a door for opening or closing the opening of the body; and supporting rods for horizontally sliding a sintering plate, on which green compacts of rare-earth magnetic alloy powder are placed. The supporting rods are secured inside the body. At least the body and the door are made of molybdenum.
    Type: Application
    Filed: June 19, 2002
    Publication date: October 31, 2002
    Applicant: SUMITOMO SPECIAL METALS CO., LTD.
    Inventors: Akiyasu Oota, Tsuyoshi Wada, Katsumi Okayama
  • Patent number: 6464386
    Abstract: A mixing apparatus comprises a mixing container having an opening. The mixing container is hollow cylindrical, having a length l.5˜2.5 times an inner diameter. The mixing container is loaded with a powder such as a metallurgical powder to 30 % ˜80% of the capacity of the mixing container. The mixing container is tilted at 10 degrees ˜40 degrees off the horizontal level and rotated while a liquid such as a lubricant is supplied to the powder in the mixing container from a nozzle portion. The nozzle portion is constituted to prevent the liquid from discharging when the supply of the liquid is not needed. After the liquid is supplied, the nozzle portion is evacuated from the mixing container while the mixing container is rocked for mixing the powder with the liquid. Thereafter, the mixing container is tilted to position the opening at a downward location, and the mixing container is given rotation and impact while unloading a mix from within the mixing container.
    Type: Grant
    Filed: February 25, 2000
    Date of Patent: October 15, 2002
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Akiyasu Oota, Akihito Tsujimoto, Katsumi Okayama
  • Patent number: 6464931
    Abstract: A case according to the present invention is used in a sintering process to produce a rare-earth magnet. The case includes: a body with an opening; a door for opening or closing the opening of the body; and supporting rods for horizontally sliding a sintering plate, on which green compacts of rare-earth magnetic alloy powder are placed. The supporting rods are secured inside the body. At least the body and the door are made of molybdenum.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: October 15, 2002
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Akiyasu Oota, Tsuyoshi Wada, Katsumi Okayama
  • Patent number: 6461565
    Abstract: A green compact of a rare earth alloy magnetic powder is made by pressing the powder. The powder is pressed within an air environment that has a temperature controlled at 30° C. or less and a relative humidity controlled at 65% or less.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: October 8, 2002
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Koki Tokuhara, Shuhei Okumura, Akiyasu Oota
  • Patent number: 6403024
    Abstract: A hydrogen pulverizer according to the present invention is an apparatus for subjecting a rare-earth alloy magnetic material to a hydrogen pulverization process. The apparatus includes: a hermetically sealable hydrogen furnace, which includes a furnace body with an opening and a cap for closing the opening; a loading chamber for temporarily enclosing the rare-earth alloy magnetic material when the rare-earth alloy magnetic material, which has been pulverized with hydrogen, is unloaded from the furnace body through the opening; and an inert gas supply for supplying an inert gas into the loading chamber.
    Type: Grant
    Filed: February 15, 2000
    Date of Patent: June 11, 2002
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Akiyasu Oota, Akihito Tsujimoto, Katsumi Okayama
  • Publication number: 20020012600
    Abstract: The method for producing a rare-earth sintered magnet of the present invention includes the steps of: compacting alloy powder for the rare-earth sintered magnet to form a green compact; loading the green compact into a case having a structure restricting a path through which gas flows between the outside and inside of the case, and placing a gas absorbent at least near the path; and sintering the green compact by heating the case including the green compact inside in a decompressed atmosphere.
    Type: Application
    Filed: May 2, 2001
    Publication date: January 31, 2002
    Inventors: Koki Tokuhara, Akiyasu Oota, Tsuyoshi Wada, Katsumi Okayama, Tomoiku Ohtani, Kunitoshi Kanno
  • Publication number: 20020006347
    Abstract: A green compact of a rare earth alloy magnetic powder is made by pressing the powder. The powder is pressed within an air environment that has a temperature controlled at 30° C. or less and a relative humidity controlled at 65% or less.
    Type: Application
    Filed: March 8, 2001
    Publication date: January 17, 2002
    Inventors: Koki Tokuhara, Shuhei Okumura, Akiyasu Oota
  • Patent number: 6247660
    Abstract: A case for hydrogen-pulverizing a rare earth metal-based magnetic material is disclosed. The case includes a case body which is formed of a material having a heat conductivity of 1 W/cm·deg or more. At least one heat-transferring/releasing member is mounted in the case body and formed of a material having a heat conductivity of 1 W/cm·deg or more. The magnetic material is accommodated in the case and subjected to a hydrogen pulverization with hydrogen occluded in the magnetic material.
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: June 19, 2001
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Yasuhiko Imai, Koki Tokuhara, Katsumi Okayama, Akiyasu Oota, Akihito Tsujimoto