US2870843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for control of flow through the annulus of a dual-zone well
Assignee: Gulf Oil Corp
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Filing: 1955-06-21
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Granted: 1959-01-27
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Expires: 1975-06-21
Abstract
No abstract record available.
Inventors
- 👤 Jr Clifford J Rodgers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:44
CPC Classifications
E; E21; E21B; E21B34/00; E21B34/06; E21B34/08; E21B43/00; E21B43/14
Claims Analysis
Total Claims: 0
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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) | 1962-01-26 | 1962-07-28 | 1963-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-26 | 1966-07-28 | 1967-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-26 | 1970-07-28 | 1971-01-27 | $7700.00 | Window Closed / Lapsed |