Patent US1863840A successfully refreshed from Google Patents.
US1863840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loud speaker apparatus and methods
Assignee: Submarine Signal Co
•
Filing: 1927-01-06
•
Granted: 1932-06-21
•
Expires: 1947-01-06
Abstract
No abstract record available.
Inventors
- 👤 Reginald A Fessenden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:17
CPC Classifications
H; H04; H04R; H04R15/00; G; G01; G01S; G01S1/00; G01S1/72; H03; H03C; H03C5/00; H04R9/00; H04R9/08
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) | 1935-06-21 | 1935-12-21 | 1936-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-06-21 | 1939-12-21 | 1940-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-06-21 | 1943-12-21 | 1944-06-21 | $7700.00 | Window Closed / Lapsed |