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:
Oct. 29, 1991
Filed:
Sep. 01, 1989
Applicant:
Inventors:
Assignee:
Voest-Alpine Stahl Donawitz Gesellschaft m.b.H., Leoben-Donawitz, AT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21B / ;
U.S. Cl.
CPC ...
72 38 ; 72364 ;
Abstract
A procedure for producing coil-forming tubes, in which the tubes are heated to a temperature of 1,000.degree.-1,100.degree. C., particularly to 1,050.degree. C. and then bent at temperatures of more than 850.degree. C. The method proceeds in such a way that the tubes are flushed with N.sub.2 or an N.sub.2 atmosphere is maintained during the heating and during the bending process, in order to increase the service life of such tubes.