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:
Jun. 16, 2015
Filed:
Nov. 20, 2009
Rolf Kümmerling, Duisburg, DE;
Manfred Bellmann, Ratingen, DE;
Winfried Braun, Düsseldorf, DE;
Hidenori Kinugasa, Wakayama, JP;
Sasaki Kenichi, Wakayama, JP;
Rolf Kümmerling, Duisburg, DE;
Manfred Bellmann, Ratingen, DE;
Winfried Braun, Düsseldorf, DE;
Hidenori Kinugasa, Wakayama, JP;
Sasaki Kenichi, Wakayama, JP;
V & M DEUTSCHLAND GmbH, Düsseldorf, DE;
Abstract
The invention relates to a method for producing seamless tubes from metal, particularly from steel, wherein a previously produced hot hollow block is stretched by means of a three-roll bar rolling mill on a mandrel to form a parent tube and, before running into the bar rolling mill, the hollow block is provided with a rolling step that makes the diameter more uniform by means of an upstream stand. It is in this case provided that the rolls of the upstream stand are moved apart and together to the same extent as the deforming stands of the bar rolling mill, wherein the calibrating base radius of the rolls of the upstream stand extends over 60° and this is followed by a flank radius with a tangential transition which is dimensioned such that even with the maximum setting of the rolls in the region of the flank there is virtually no diameter reduction of the largest hollow block diameter to be expected.