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. 11, 1997
Filed:
Nov. 29, 1994
Robert M Hunter, Bozeman, MT (US);
Frank M Stewart, Bozeman, MT (US);
William H Hunter, Bozeman, MT (US);
Other;
Abstract
Underground pipelines that carry wastewater, water, natural gas, and industrial fluids deteriorate with age. This invention is a process and apparatus for installing a thermoplastic liner in a dry pipeline to accomplish in situ rehabilitation. It involves extruding a tube of thermoplastic liner material within the interior of a dried and preheated pipeline in situ, said tube having an outside diameter smaller than the inside diameter of said pipeline. The tube is next expanded so that the outside diameter of said tube is substantially equal to the inside diameter of said pipeline. The expanded tube is then cooled and hardened in a liner configuration.