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.

Date of Patent:
Feb. 25, 1986

Filed:

Nov. 16, 1984
Applicant:
Inventors:

Hermann Moltner, Grevenbroich, DE;

Karl-Hans Staat, Homberg, DE;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21B / ; B21B / ; B21C / ;
U.S. Cl.
CPC ...
72 68 ; 72 97 ; 72 96 ; 72209 ;
Abstract

In a rolling mill plant for the manufacture of seamless tubes, a piercing mill (2), a planetary skew rolling mill (15) and a sizing or stretch-reducing rolling mill (18) are arranged one after the other. In order to improve the output and the quality of the products of plant of this kind, it is proposed not to withdraw the shaft rods (11) used during the piercing operation in the mill (2), but also to use them as internal tools in the planetary skew rolling mill (15). The shaft rods can then remain at the entry end upstream of the planetary skew rolling mill (15) from where they can be returned to the piercing mill (2). Alternatively (FIGS. 2 and 4) they can also pass through the planetary skew rolling mill and be returned from the delivery end thereof to the piercing mill. The insertion, hitherto required, of rods into the hollow ingots before entering the planetary skew rolling mill is not required. The heavy scaling of the surface of the bore in the hollow ingot thereby occurring is avoided.


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