Patents by Inventor Koichi Kurosawa

Koichi Kurosawa 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).

  • Method and structure for repairing an elongated metal hollow member
    Patent number: 5267279
    Abstract: A part of an ICM housing including a portion to be repaired, welded to a wall of a reactor pressure vessel in operation, is cut and removed and a new ICM housing half is welded to the remaining part of the ICM housing to form a new ICM housing. The new ICM housing is provided at the welding portion thereof with a molten metal layer containing 4 wt % or more .delta. ferrite. A sleeve made of stainless steel is located at the welding portion of an inner peripheral surface of the new ICM housing made so as to be molten by a TIG welding machine to form the molten metal layer, with the molten metal layer preventing stress corrosion cracking of the new ICM housing.
    Type: Grant
    Filed: January 9, 1991
    Date of Patent: November 30, 1993
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Hideyo Saito, Koichi Kurosawa, Takayuki Numata, Shigeo Hattori, Takenori Shindo
  • Method and structure for preventive maintaining an elongated metal hollow member
    Patent number: 5227124
    Abstract: An ICM housing welded to a wall of a reactor pressure vessel in operation is provided with a molten metal layer containing 4 wt. % or more .delta. ferrite at a portion of an inner peripheral surface thereof which corresponds to a weld. A sleeve made of stainless steel is located at the competent portion of the inner peripheral surface of the ICM housing stainless steel so as to be molten by means of a TIG welding machine to form the molten metal layer. The molten metal layer prevents stress corrosion cracking of the ICM housing.
    Type: Grant
    Filed: August 2, 1990
    Date of Patent: July 13, 1993
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha, Hitachi Kyowa Kogyo Co., Ltd.
    Inventors: Hideyo Saito, Koichi Kurosawa, Takayuki Numata, Shigeo Hattori, Takenori Shindo