Assembly of hollow torque transmitting sucker rods
US6764108B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2002 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | Sep 26, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16L15/004
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An elongated drive string assembly includes a plurality of hollow sucker rods and connecting elements with an axis, connected together and between a drive head located at the surface of an oil well and a rotary pump located deep down in an oil well. Each hollow sucker rod has at least a first end including an internal female threaded surface engaging an external male threaded surface on a connecting element, such as a nipple. The first end also includes a torque shoulder, which engages a torque shoulder formed on the connecting element. The threads are frusto-conical, non-symmetrical threads with a differential diametral taper. The torque shoulders have a maximized mean diameter and cross-sectional area to resist storing reactive torque in the drive string. The nipple has a wall cross-section that increases towards the torque shoulders from each free end, to increase fatigue resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.