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:
Apr. 15, 2003
Filed:
Jul. 30, 2001
Thomas Joseph Keyes, Ft. Worth, TX (US);
James Bass, Ft. Worth, TX (US);
Thermacor Process, Inc., Fort Worth, TX (US);
Abstract
A method is shown for manufacturing a polyethylene jacket of the type used in pre-insulated piping systems. A mandrel is first coated with a brittle polymeric coating. A melt profile of polyethylene is then extruded onto the mandrel and spirally wound to produce adjacent windings. The adjacent windings make contact to form a finished jacket which is in engagement with the brittle coating. After the jacket has set, an external compressive force is applied to the tubular member thus formed sufficient to crush the internal brittle coating, thereby freeing the polyethylene jacket from engagement with the mandrel. The jacket can then be removed from the mandrel.