US2884492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct coupled series amplifier
Assignee: Schlumberger Well Surveying Corp
•
Filing: 1954-12-08
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Granted: 1959-04-28
•
Expires: 1974-12-08
Abstract
No abstract record available.
Inventors
- 👤 William H Swain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:30
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/42; H03F3/44
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR1056347A
Cited
GB412182A
Cited
US2326614A
Cited
US2438960A
Cited
US2525632A
Cited
US2679029A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-27 | 1962-10-27 | 1963-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-27 | 1966-10-27 | 1967-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-27 | 1970-10-27 | 1971-04-28 | $7700.00 | Window Closed / Lapsed |