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:
Sep. 22, 1998
Filed:
Dec. 11, 1996
Ivan C Mandich, New Orleans, LA (US);
Other;
Abstract
A thermoplastic liner is extruded in cylindrical form and deformed at a temperature below the crystallization temperature of the polyethylene material forming the liner into a generally W-shaped configuration. The liner in that configuration has three convex lobes and two concave lobes along one side of the liner with a convex portion of the liner wall along the opposite side. The cylindrical liner is initially extruded in cylindrical form and deformed by a series of axially spaced sets of rollers progressively inclined toward a vertical position wherein the final W-shaped configuration of the liner is formed. The liner has a cross-section in any direction less than one-half of the diameter of the liner when expanded into a cylindrical configuration. The deformed liner is coiled about a reel. At an installation site, the liner is pulled from the reel through the pipe and sealed at opposite ends. Steam under pressure expands the W-shaped liner to a cylindrical configuration to line the pipe.