US3850461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Threaded tube joint structure for a casing
Assignee: Nippon Steel Corp
•
Filing: 1973-03-30
•
Granted: 1974-11-26
•
Expires: 1993-03-30
Abstract
Abstract A threaded tube joint having a seal structure consisting of a metal-to-metal forced contact seal which also serves to augment the sealing effect of a tetrafluroethylene packing by holding it under an extremely high pressure so as to effect a tighter combined seal.
Inventors
- 👤 Y Fujioka
- 👤 T Ryujin
- 👤 S Yoshida
- 👤 M Inagaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:41
CPC Classifications
F; F16; F16L; F16L15/00; F16L15/001; F16L15/003; E; E21; E21B; E21B17/00; E21B17/02; E21B17/08; F16L15/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
184 words
A threaded tube joint for a casing, comprising a tapered male-threaded portion of a metal tubing section, and a metal tubular coupler having a female thread thereon in threaded engagement with said male-threaded portion, said coupler having an inner flaring threadless surface portion extending parallel to and toward said tubing section by a constant amount from the taper profile formed at the crest of the female threads, said coupler also having an annular inner groove located between said inner flaring surface and the forwardmost thread of said coupler, a packing of tetrafluoroethylene located within said groove, said tubing section having threadless forward end portion of the same taper as that of said flaring surface of said coupler, and a forward side wall surface of said groove nearer the center of said coupler being in metaL-to-metal force contact with a forward end portion of the forwardmost thread of said tubing section, a first metal-to-metal seal being formed between said threadless surface portion and said threadless forward end portion, and a second seal being formed between said packing and said forwardmost thread of said tubing section.
Claim 2
Dependent Claim
184 words
A threaded tube joint for a casing, comprising a tapered male-threaded portion of a metal tubing section, and a metal tubular coupler having a female thread thereon in threaded engagement with said male-threaded portion, said coupler having an inner flaring threadless surface portion extending parallel to and toward said tubing section by a constant amount from the taper profile formed at the crest of the female threads, said coupler also having an annular inner groove located between said inner flaring surface and the forwardmost thread of said coupler, a packing of tetrafluoroethylene located within said groove, said tubing section having threadless forward end portion of the same taper as that of said flaring surface of said coupler, and a forward side wall surface of said groove nearer the center of said coupler being in metaL-to-metal force contact with a forward end portion of the forwardmost thread of said tubing section, a first metal-to-metal seal being formed between said threadless surface portion and said threadless forward end portion, and a second seal being formed between said packing and said forwardmost thread of said tubing section.
Claim 3
Dependent Claim
44 words
The threaded tube joint according to claim 1, wherein the constant amount extension of said threadless surface portion is within a range of between 0.10 and 0.40 millimeters, and has an axial dimension within a range of 1 to 2 times the thread pitch.
Claim 4
Dependent Claim
29 words
The threaded tube joint according to claim 1, wherein said forwardmost thread of said tubing section is partially tapered away from said forward side wall surface of said groove.
Claim 5
Dependent Claim
49 words
The threaded tube joint according to claim 1, wherein said coupler has an inner annular projection at said center, said projection defining a stopper surface, whereby a third metal-to-metal forced contact seal is formed between the end face of said tubing section forward end portion and said stopper surface.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |