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. 20, 1992
Filed:
Apr. 18, 1990
Alfred Lampe, Willich, DE;
Gheorghe Arnatu, Dusseldorf, DE;
Hermann J Frentzen, Monchen-gladbach, DE;
Mannesmann Aktiengesellschaft, Dusseldorf, DE;
Abstract
Seamless tubes are manufactured from a hollow ingot introduced into a continuous-tube rolling mill. The hollow ingot is deformed, directly before introduction into a first stand of the rolling mill, so that without reduction in wall thickness the clearance between a mandrel and an inner surface of the hollow ingot in the region of a base of the groove of the rolls of the first stand is greater than the clearance in the region of roll flanks of the first stand. This advantageously increases the stretch in the first roll groove so that, on one hand, the total stretch limit can be increased and, on the other hand, the central roll groove can be relieved.