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Patent US2856206A successfully refreshed from Google Patents.
US2856206A
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Flexible seal-supporting flange for wellhead couplings
Assignee: Cooper Industries LLC
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Filing: 1954-09-22
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Granted: 1958-10-14
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Expires: 1974-09-22
Abstract
No abstract record available.
Inventors
- 👤 Robert L Barber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:40
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/02; E21B33/03; E21B33/04; E21B33/0422
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US963688A
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US1834444A
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US1908120A
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US2144227A
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US2209325A
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US2230589A
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US2350867A
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US2312476A
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US2313308A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-13 | 1962-04-14 | 1962-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-13 | 1966-04-14 | 1966-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-13 | 1970-04-14 | 1970-10-14 | $7700.00 | Window Closed / Lapsed |