The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jan. 05, 1999

Filed:

Sep. 03, 1996
Applicant:
Inventors:

Shigeru Toyoda, Saitama-ken, JP;

Shuichi Yagi, Kanagawa-ken, JP;

Masaaki Itagaki, Kanagawa-ken, JP;

Assignee:

Tokyo Gas Co. Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29C / ; B29C / ; B29C / ;
U.S. Cl.
CPC ...
156 94 ; 156287 ; 156294 ;
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.


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