Tubular connection with S-thread form for clamping center seal
US5154452A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 1991 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Sep 18, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/0423
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A tubular connection employing two separate non-concurrent threaded sections, each of which nearly decays, that is, runs out on a tubular surface, one on the outside diameter of the male tubular member, and one on the inside diameter of the female tubular member, thus providing a joint with nearly the strength of the tubular body in tension without the use of a coupling. The female tubular member is expanded through a cold swaging operation before being finished with the two threaded sections. Additionally, the connection features a torque stop and cylindrical seal in the middle of the two thread steps, where stresses may be kept low. The thread elements are reverse angle locking with S-shaped load flanks which reduce stress concentrations and provide a clamping action on the centralized seal. Because of this unique seal, the connection can take cyclic application of external and internal pressure without leaking, a feat non-coupled and non-upset connections of prior art have not achieved. This invention is a total optimization of tension efficiency, pressure integrity, and low stress compared to all other connections of its genre.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.