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:
Mar. 02, 1993
Filed:
Jun. 12, 1991
Applicant:
Inventors:
Wolfgang Streubel, Barntrup, DE;
Rainer Hansen, Paderborn-Elsen, DE;
Assignee:
Benteler Aktiengesellschaft, Paderborn, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
29890149 ; 29424 ;
Abstract
A double walled pipe elbow with an intermediate space between an inner pipe and an outer pipe is formed by joining the ends of a straight inner pipe and a straight outer pipe. The two pipes are bent into a desired shape and then placed in a shaping recess in a shaping tool. Seal plugs are placed at the opposite ends of the pipe elbow. In the sealed condition, a pressurized medium is supplied through at least one end seal plug into the inner pipe and between the inner and the outer pipe for expanding the outer pipe into surface contact with the shaping recess.