Patents by Inventor Hisao Ootsuga

Hisao Ootsuga 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 of repairing pipes laid underground
    Patent number: 4556580
    Abstract: A method for repairing pipes laid underground, such as gas pipes, consisting of a main supply pipe from which numerous distribution pipes branch off to supply the individual users, the method using resin to repair the main supply pipe and the distribution pipes from the inside while in their buried state.The repair method of this invention is characterized by the fact that, having repaired the main supply pipe and the distribution pipe in successive operations, whether the repairs to the main supply pipe and the distribution pipes have been done properly or not can be confirmed on completion of the repairs by carrying out sealage tests on the distribution pipes and the main supply pipe.
    Type: Grant
    Filed: December 24, 1984
    Date of Patent: December 3, 1985
    Assignees: Tokyo Gas Co., Ltd., Hakko Co., Ltd.
    Inventors: Takashi Kamuro, Hisao Ootsuga, Isao Saito, Motoyuki Koga