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.
Patent No.:
Date of Patent:
Feb. 23, 1999
Filed:
Jul. 19, 1996
Shinobu Satake, Tokyo, JP;
Tadao Yahata, Kanagawa-ken, JP;
Takashi Shigefuji, Tokyo, JP;
Shigeru Toyoda, Saitama-ken, JP;
Shuichi Yagi, Kanagawa-ken, JP;
Masaaki Itagaki, Kanagawa-ken, JP;
Tokyo Gas Co., Ltd., Tokyo, JP;
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 the pipe by means of the second pig.