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, 1982
Filed:
Sep. 03, 1980
Applicant:
Inventors:
Assignee:
Mannesmann Aktiengesellschaft, Dusseldorf, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
72 62 ; 72 58 ;
Abstract
A hollow blank, such as a tube, is inserted in between two dies and is also received by two retractable die members. The interior of the blank is closed off, but working fluid is admitted to widen the blank. Widening is at first restricted to a central portion established by conical front faces of the die members. These members are retracted while continued application of fluid pressure progressively widens the blank, urging blank material into continued abutment with the front faces of the receding die members.