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:
Jul. 18, 2000
Filed:
Mar. 04, 1999
Applicant:
Inventors:
Ettore Cernuschi, Bareggio, IT;
Gerhard Kulessa, Mllheim, DE;
Thomas Leisten, Huckelhoven, DE;
Jurgen Pietsch, Monchengladbach, DE;
Walter Randerath, Viersen, DE;
Frank Salomon, Willich, DE;
Assignee:
Mannesmann AG, Dusseldorf, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21B / ;
U.S. Cl.
CPC ...
72 97 ;
Abstract
A process for producing a hollow billet for producing tubing for antifriction bearings includes massively reducing a bloom in a three-roll rotary piercing mill and subsequently piercing the reduced bloom in a three-roll rotary piercing mill. The reducing and piercing may be performed in one-pass through the three-roll rotary piercing mill. The reducing and piercing steps may also be performed in separate passes through the same mill or through two separate mills.