US2920140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic microphone circuits
Assignee: RCA Corp
•
Filing: 1958-03-14
•
Granted: 1960-01-05
•
Expires: 1978-03-14
Abstract
No abstract record available.
Inventors
- 👤 Adolph R Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:54
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/04
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2678967A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-04 | 1963-07-06 | 1964-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-04 | 1967-07-06 | 1968-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-04 | 1971-07-06 | 1972-01-05 | $7700.00 | Window Closed / Lapsed |