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:
Dec. 31, 1996
Filed:
Mar. 19, 1993
Campbell H Steketee, Jr, Salem, OR (US);
NuPipe, Inc., Memphis, TN (US);
Abstract
A thermoplastic pipe for installation in an existing conduit is manufactured in folded form and spooled for storage. The pipe is then reheated to make it pliable for installation and pulled into the conduit for lateral periods. Steam under pressure is used to round the installed pipe. The leading end of the replacement pipe may be restricted by an end clamp which enables hot fluid to pass completely through the pipe and heat the full length, or by an inflatable plug which is displaced to the leading end of the replacement pipe after installation. Methods and apparatus for the manufacturing of the pipe include extruding heated thermoplastic pipe material through a die to form a tubular shape, shaping the resulting hot tubular plastic material in the molten state to the folded form and cooling to provide a pipe with a memory for the folded form.