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:
Apr. 28, 2020
Filed:
Nov. 24, 2015
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Mitsubishi Hitachi Power Systems, Ltd., Kanagawa, JP;
Takashi Nakashima, Wakayama, JP;
Atsuro Iseda, Tokyo, JP;
Takeshi Miki, Wakayama, JP;
Shunichi Otsuka, Wakayama, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
MITSUBISHI HITACHI POWER SYSTEMS, LTD., Kanagawa, JP;
Abstract
The production method for producing a rifled tube, which includes a plurality of first helical ribs on its inner surface, includes: a steps of: preparing a steel tube; and producing a rifled tube by performing cold drawing on a steel tube by using a plug which includes a plurality of second helical ribs, the plug satisfying Formulae and:0.08 <×()×/(2π×)<0.26  (1)0.83<×()×/(2×)<2.0  (2)where, W is a width of a groove bottom surface of the helical groove; A is a maximum diameter of the plug; B is a minimum diameter of the plug; N is a number of the second helical ribs; S is the width of the groove bottom surface; and M is a pitch of adjacent second helical ribs.