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:
Nov. 13, 2018
Filed:
Jun. 09, 2014
Jfe Steel Corporation, Tokyo, JP;
Takamasa Kawai, Tokyo, JP;
Kazunari Takahashi, Tokyo, JP;
Hiroshi Chikatsune, Tokyo, JP;
Masaki Yoshikawa, Tokyo, JP;
Jun Takano, Tokyo, JP;
Takuya Nagahama, Tokyo, JP;
Masateru Ueta, Tokyo, JP;
Hideo Sato, Tokyo, JP;
Haruhiko Seki, Tokyo, JP;
Tsuyoshi Yoneyama, Tokyo, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
In a joint for oil country tubular goods, a pitch change is made such that an internally-thread pitch has the same value as an externally-thread pitch from a thread end portion on a box end side to a pitch change position taken on a box center side with respect to a position away from the thread end portion by ½ of an entire length of the threaded portion, and the internally-thread pitch is changed to a value less than the externally-thread pitch at the pitch change position so that a thread gap is gradually decreased from the pitch change position to a position of the thread end portion on the box center side, and the thread gap is eventually set to a value which is 0.2 to 0.8 times as large as the thread gap before the pitch change is made.