US3470972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bottom-hole pressure regulation apparatus
Assignee: Warren Automatic Tool Co
•
Filing: 1967-06-08
•
Granted: 1969-10-07
•
Expires: 1987-06-08
Abstract
No abstract record available.
Inventors
- 👤 Ethell J Dower
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:32
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2102865A
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US3073350A
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US3338319A
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US3362487A
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US3396793A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-06 | 1973-04-07 | 1973-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-06 | 1977-04-07 | 1977-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-06 | 1981-04-07 | 1981-10-07 | $7700.00 | Window Closed / Lapsed |