Threaded joint for oil country tubular goods
US10125554B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 2014 |
| Grant date | Nov 13, 2018 |
| Priority date | — |
| Expiry date | Apr 29, 2035 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16L15/06
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.