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. 03, 1985
Filed:
Jun. 11, 1984
Applicant:
Inventor:
Stuart E Reed, Homeworth, OH (US);
Assignee:
The Babcock & Wilcox Company, New Orleans, LA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
72367 ; 2945 / ; 72378 ;
Abstract
A tubular apparatus is assembled of inner and outer tubes which are connected at spaced locations along their length. After heat treatment and other processing steps, either the inner or outer tube is heated to reduce its yield strength and then stretched beyond its yield point but not beyond the yield point of the other tubular. The heat source is removed so that the stretched state is maintained. The tubular apparatus is thus prestressed with the inner tube under compressive prestressing when the inner tube has been heated and stretched, and the inner tube under tensile prestressing when the outer tube has been heated and stretched.