US3589550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible thread systems for high-pressure vessels and the like
Assignee: National Forge Co
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Filing: 1969-11-17
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Granted: 1971-06-29
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Expires: 1989-11-17
Abstract
Abstract A flexible thread system for use on screw-type closure structures for high-pressure vessels and the like wherein a gullet, with a paraboliclike taper, is provided below the normal root portion of one, or both, of the mating male and female threads of the screw-type closure, the gullet or gullets enabling the thread cross section to deflect as a lever in order to enable the closure threads to be uniformly stressed and to accommodate the pressurized stress patterns of the vessel system.
Inventors
- 👤 Peter F Rossmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:05
CPC Classifications
F; F16; F16B; F16B33/00; F16B33/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
In a thread system for use on screw-type closure structures for high-pressure vessels and the like wherein a threaded-type plug closure member is screwed into a complementary threaded opening into the vessel, the improvement wherein a paraboliclike tapered gullet is provided below the normal root portion of at least one of the two mating threads, the depth of the gullet increasing in the direction of the end of the thread nearest the interior of the vessel, the gullet establishing a flexibility characteristic enabling the thread cross section to deflect as a lever in order to enable said closure threads to be uniformly stressed and to accommodate pressurized stress patterns of the vessel system.
Claim 2
Dependent Claim
113 words
In a thread system for use on screw-type closure structures for high-pressure vessels and the like wherein a threaded-type plug closure member is screwed into a complementary threaded opening into the vessel, the improvement wherein a paraboliclike tapered gullet is provided below the normal root portion of at least one of the two mating threads, the depth of the gullet increasing in the direction of the end of the thread nearest the interior of the vessel, the gullet establishing a flexibility characteristic enabling the thread cross section to deflect as a lever in order to enable said closure threads to be uniformly stressed and to accommodate pressurized stress patterns of the vessel system.
Claim 3
Dependent Claim
19 words
A flexible thread system as defined in claim 1 wherein a gullet is provided for each of said threads.
Claim 4
Dependent Claim
94 words
A flexible thread system as defined in claim 1 wherein the depth of the gullet increases in the direction of the end of the thread nearest the interior of the vessel substantially in accordance with a curve expressed by the formula: 6.31 b2d/B2D + 0.75 bd2/BD2 + 0.0156 d3/D3 - 1 0 where: D thread depth, B the axial length of the threaded opening, b the distance along the threads measured from the first load-bearing thread, d the depth of the gullet measured from the extreme edge of the thread at the distance b.
Claim 5
Dependent Claim
26 words
A flexible thread system as defined in claim 1 wherein crowns are provided at both the tip and root ends of at least one mating thread.
Claim 6
Dependent Claim
20 words
A flexible thread system as defined in claim 1 wherein the flanks of both of the mating threads are crowned.
References Cited (Backward Citations)
US2263644A
Cited
GB806553A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |