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:
May. 22, 1984
Filed:
Mar. 16, 1982
Kawasaki Jukogyo Kabushiki Kaisha, Hyogo, JP;
Abstract
A double-wall composite pipe is produced by inserting an inner pipe in an outer pipe, filling the inner pipe with cold water under pressure to cause the inner pipe to expand plastically into tight contact with the outer pipe, applying heat to the outer part of the outer pipe by high-frequency induction heating, thereby to establish a locally heated zone thereof around the circumference thereof and causing the heated zone to travel from one end to the other end of the outer pipe thereby to cause it to successively expand locally in diameter in the travelling heated zone. The pressure in the inner pipe then is removed, the pipes thereafter being permitted to attain the ambient temperature, thereby to obtain an interference fit therebetween.