Patents by Inventor Shuichi Yagi

Shuichi Yagi 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: 5993581
    Abstract: There is provided an adhesive composition for use as an adhesive agent for bonding a flexible lining tube on to the internal surface of an existing old pipe. Such an adhesive composition comprises: a) an epoxy resin; b) a thixotropy agent mainly containing silica fine particles; c) a lubricant mainly containing spheroidal fine particles; d) a curing agent having a sufficient compatibility with the thixotropy agent, and being used in a sufficient amount to cure the epoxy resin. In particular, the above components a),b),c) together form a main agent, and the above components b) and d) together form an auxiliary agent. Before use, the main agent and the auxiliary agent are separated from each other. When in use, the main agent and the auxiliary agent are mixed together, so as to form the adhesive composition for use as an adhesive agent for bonding a flexible lining tube on to the internal surface of the existing old pipe.
    Type: Grant
    Filed: March 30, 1998
    Date of Patent: November 30, 1999
    Assignees: Tokyo Gas Co., Ltd., Three Bond Co., Ltd., Three Bond Unicom Co., Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki, Yukio Sato, Kiyoshi Shinkado
  • Patent number: 5983948
    Abstract: A method of repairing an existing pipeline including a main pipe and a branch pipe, includes the steps of introducing a first lining pig, a first batch of a resin, and some other pigs into the branch pipe and supplying a first batch of a liquid into the branch pipe until the first lining pig reaches a branching position; introducing a second lining pig, a second batch of a resin, and some other pigs into the main pipe and supplying a second batch of a liquid into the main pipe until the second lining pig reaches an inner end thereof; drawing back the second batch of the liquid out of the main pipe so as to cause the second batch of the resin to move back toward an open end of the main pipe, thereby forming a resin lining layer on the internal surface of the main pipe; drawing back the first batch of the liquid out of the branch pipe so as to cause the first batch of the resin to move back toward an open end of the branch pipe, thereby forming a resin lining layer on the internal surface of the branch pipe.
    Type: Grant
    Filed: December 2, 1998
    Date of Patent: November 16, 1999
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shuichi Yagi, Masaaki Itagaki, Kenji Morita
  • Patent number: 5899636
    Abstract: A reversible lining tube for repairing an existing pipeline is reversible into the existing pipeline so that its initial inner surface becomes its outer surface which adheres to the internal surface of the pipeline. In detail, the reversible lining tube includes an elastomer layer and a flock layer, prior to reversal into the existing pipeline the elastomer layer is an outer layer and the flock layer is an inner layer, upon reversal into the existing pipeline the elastomer layer becomes an inner layer and the flock layer becomes an outer layer which adheres to the internal surface of the existing pipeline.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: May 4, 1999
    Assignees: Tokyo Gas Co. Ltd., Nisshinbo Industries, Inc.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki, Kazuki Okabe
  • Patent number: 5888302
    Abstract: There is provided a suction system for use in a method of lining the internal surface of a pipe, said suction system comprises a pig receiving device to be attached to an open end of the pipe, a liquid receiving tank connected with the pig receiving device, and a suction pump connected with the liquid receiving tank. Further, a pig detecting device for detecting the passing of a pig is provided between the open end of the pipe and the pig receiving device, a suction force controlling device is provided between the pig receiving device and the liquid receiving tank, and a gas-liquid separation apparatus is provided between the liquid receiving tank and the suction pump.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: March 30, 1999
    Assignee: Tokyo Gas Co. Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • 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
  • Patent number: 5855712
    Abstract: A method of repairing an existing pipe includes steps of introducing at least one leading pig into the existing pipe through one open end thereof, introducing behind the leading pig a necessary amount of adhesive agent into the existing pipe through the same open end thereof, fixing one end of a liner tube at the above open end of the existing pipe, in a manner such that the liner tube may be reversed into the existing pipe, and providing a negative pressure into the existing pipe through an opposite open end thereof to cause the leading pig and the adhesive agent to move forwardly and thus cause the unfixed portions of the liner tube to be reversed into the existing pipe. The adhesive agent is caused to move through the existing pipe in the form of a plug flow, thereby coating the whole internal surface of the existing pipe with the adhesive agent, ensuring that the liner tube reversed into the pipe may adhere to the internal surface of the existing pipe.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: January 5, 1999
    Assignee: Tokyo Gas Co. Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • Patent number: 5853629
    Abstract: Methods of lining the internal surface of a pipe, include first inserting two lining pigs into the pipe and then introducing a batch of resin thereinto, or inserting one lining pig between two batches of a resin, or first inserting a lining pig and then inserting two batches of a resin with another lining pig therebetween, or first introducing a lining pig made of a soft material capable of deforming so as to pass through a narrow-passing section and then introducing a batch of a resin into the pipe, causing the resin to move forward until the front end of the resin reaches an inner end of the pipe, and sucking the resin back from the inner end so as to line the internal surface of the pipe with the resin. The methods use improved liquid blocking pigs for use in pipe lining treatment, each of such pigs includes a spherical body made of a soft resilient material and at least one flexible liquid barrier diaphragm interposed in the spherical body.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: December 29, 1998
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • 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
  • Patent number: 5716672
    Abstract: There are provided methods of lining the internal surface of a pipe, which includes first inserting two lining pigs into the pipe and then introducing a batch of resin thereinto, or inserting one lining pig between two batches of a resin, or first inserting a lining pig and then inserting two batches of a resin with another lining pig therebetween, or first introducing a lining pig made of a soft material capable of deforming so as to pass through a narrow-passing section and then introducing a batch of a resin into the pipe, causing the resin to move forward until the front end of the resin reaches an inner end of the pipe, and sucking the resin back from the inner end so as to line the internal surface of the pipe with the resin. There are also provided improved liquid blocking pigs for use in pipe lining treatment, each of such pigs comprises a spherical body made of a soft resilient material and a least one flexible liquid barrier diaphragm interposed in the spherical body.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: February 10, 1998
    Assignee: Tokyo Gas Co., LTD.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • Patent number: 5700405
    Abstract: Methods of lining the internal surface of a pipe include first inserting two lining pigs into the pipe and then introducing a batch of resin thereinto, or inserting one lining pig between two batches of a resin, or first inserting a lining pig and then inserting two batches of a resin with another lining pig therebetween, or first introducing a lining pig made of a soft material capable of deforming so as to pass through a narrow-passing section and then introducing a batch of a resin into the pipe, causing the resin to move forward until the front end of the resin reaches an inner end of the pipe, and sucking the resin back from the inner end so as to line the internal surface of the pipe with the resin. The methods use improved liquid blocking pigs for use in pipe lining treatment, each of such pigs includes a spherical body made of a soft resilient material and at least one flexible liquid barrier diaphragm interposed in the spherical body.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: December 23, 1997
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • Patent number: 5667841
    Abstract: There are provided methods of lining the internal surface of a pipe, which includes first inserting two lining pigs into the pipe and then introducing a batch of resin thereinto, or inserting one lining pig between two batches of a resin, or first inserting a lining pig and then inserting two batches of a resin with another lining pig therebetween, or first introducing a lining pig made of a soft material capable of deforming so as to pass through a narrow-passing section and then introducing a batch of a resin into the pipe, causing the resin to move forward until the front end of the resin reaches an inner end of the pipe, and sucking the resin back from the inner end so as to line the internal surface of the pipe with the resin. There are also provided improved liquid blocking pigs for use in pipe lining treatment, each of such pigs comprises a spherical body made of a soft resilient material and a least one flexible liquid barrier diaphragm interposed in the spherical body.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: September 16, 1997
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • Patent number: 5632818
    Abstract: There is provided a liquid injection apparatus for use in a method of lining the internal surface of a pipe. The apparatus comprises a push car having a frame structure, a liquid tank for storing a necessary amount of liquid to be injected into the pipe, a liquid pump for pumping the necessary amount of liquid so as to inject the liquid into the pipe, and a liquid injection controlling device for controlling the pressure of the liquid being supplied through the liquid pump, for stopping the liquid injection after a predetermined amount of liquid has been injected into the pipe, and for stopping the liquid injection if the liquid pressure in the pipe changes beyond a predetermined range. The liquid tank, the liquid pump and the liquid injection controlling device are installed together in the push car so as to be easily movable.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: May 27, 1997
    Assignee: Tokyo Gas Co., Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki
  • 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
  • Patent number: 5590689
    Abstract: There is provided a method for lining the internal surface of a pipe having a first open end and a second open end.
    Type: Grant
    Filed: March 1, 1996
    Date of Patent: January 7, 1997
    Assignees: Tokyo Gas Co. Ltd., Hakko Co., Ltd.
    Inventors: Shigeru Toyoda, Shuichi Yagi, Masaaki Itagaki, Nobukatsu Ike, Kenji Ohshima