Patents by Inventor Tadao Yahata

Tadao Yahata 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).

  • Methods of lining the internal surface of a pipe
    Patent number: 5873390
    Abstract: There is provided a method of lining the internal surface of a pipe involving a larger diameter portion, said method comprising the steps of inserting a first pig into the pipe from an open end thereof, said first pig being a spherical body made of a resilient material having a diameter larger than the pipe inner diameter and having a number of grooves formed on the surface thereof for permitting air escape, injecting behind the first pig a necessary amount of resin into the pipe, inserting behind the resin a second pig into the pipe, said second pig having a diameter smaller than the pipe inner diameter such that a resin lining layer having a desired thickness may be formed on the internal surface of the pipe, providing a positive pressure and applying the positive pressure behind the second pig in the pipe, and causing the first pig, the resin and the second pig to move through the pipe along the entire length thereof by the positive pressure, so as to form a resin lining layer on the internal surface of th
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: February 23, 1999
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shinobu Satake, Tadao Yahata, Takashi Shigefuji, Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • Methods of lining the internal surface of a pipe
    Patent number: 5740838
    Abstract: There is provided a method of lining an existing underground main pipe involving a branch pipe.
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: April 21, 1998
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shinobu Satake, Tadao Yahata, Takashi Shigefuji, Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • Methods of lining the internal surface of a pipe
    Patent number: 5609186
    Abstract: There is provided a method of lining an existing underground main pipe involving a branch pipe.
    Type: Grant
    Filed: November 1, 1995
    Date of Patent: March 11, 1997
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shinobu Satake, Tadao Yahata, Takashi Shigefuji, Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki