US2000523A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone sound reproducer
Assignee: RCA Corp
•
Filing: 1931-03-13
•
Granted: 1935-05-07
•
Expires: 1951-03-13
Abstract
No abstract record available.
Inventors
- 👤 Harold D Knapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:13
CPC Classifications
H; H04; H04R; H04R5/00; H04R5/02; H04R5/023; H04R1/00; H04R1/10; H04R1/1008; H04R1/1041; H04R1/44
Claims Analysis
Total Claims: 0
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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) | 1938-05-06 | 1938-11-05 | 1939-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-05-06 | 1942-11-05 | 1943-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-05-06 | 1946-11-05 | 1947-05-07 | $7700.00 | Window Closed / Lapsed |