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:
May. 21, 2019
Filed:
Dec. 18, 2014
Jfe Steel Corporation, Tokyo, JP;
Masaki Yoshikawa, Handa, JP;
Hiroshi Chikatsune, Handa, JP;
Kazunari Takahashi, Handa, JP;
Takuya Nagahama, Handa, JP;
Jun Takano, Handa, JP;
Masateru Ueta, Houston, TX (US);
Takamasa Kawai, Handa, JP;
JFE Steel Corporation, , JP;
Abstract
A threaded joint is adapted for tubes where the stress or the strain concentration hardly occur at a threaded corner portion of box side even when the threaded joint receives repeated tensile-compressive forces or repeated bending forces. In a radial seal type threaded joint, tensile efficiency TE (%) defined by a ratio S/Sbetween a cross-sectional area S, an area of Critical Cross Section (CCS) including a portion where a tensile stress and a strain become the highest in a tube circumferential cross section of a box and a cross-sectional area Sof a tube body satisfies formula TE (%)≥2.25×t/ρ+99.9 having a ratio t/ρ between an internal thread height t of the box and a radius of curvature ρ of a corner portion of internally-threaded bottom load surface side.