US1999176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and means for signaling by frequency fluctuation
Assignee: RCA Corp
•
Filing: 1928-01-28
•
Granted: 1935-04-30
•
Expires: 1948-01-28
Abstract
No abstract record available.
Inventors
- 👤 Walter J Albersheim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:32
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/02; H03C3/04; H03C3/08
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1938-04-29 | 1938-10-29 | 1939-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-04-29 | 1942-10-29 | 1943-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-04-29 | 1946-10-29 | 1947-04-30 | $7700.00 | Window Closed / Lapsed |