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. 08, 1981
Filed:
Jul. 09, 1979
Klaus-Dieter Konrad, Oberhausen, DE;
Rudolf Kellersohn, Hamminkeln, DE;
Hans Steck, Oberhausen, DE;
Josef Schaub, Oberhausen, DE;
Ruhrchemie Aktiengesellschaft, Oberhausen, DE;
Abstract
In a method for heated tool butt welding of pipe consisting of a thermoplastic material by placing or pressing the surfaces to be joined of the pipes to be welded into contact with a heated tool to form an inner weld bead at each end to be joined, subsequently heating the surfaces at a reduced contact pressure to the welding temperature and fitting the surfaces together under pressure after having removed the heated tool, the improvement for minimizing the formation of a protrusion within the resultant pipes which comprises pressing an elastic insert against the inner weld bead while joining said surfaces of said pipe together.