US2461945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Receiver connection in electroacoustic duplex system
Assignee: FIRM AUTOPHON AG
•
Filing: 1945-01-20
•
Granted: 1949-02-15
•
Expires: 1965-01-20
Abstract
No abstract record available.
Inventors
- 👤 Tschumi Otto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:07
CPC Classifications
H; H04; H04M; H04M9/00; H04M9/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1773776A
Cited
US1975932A
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US2030987A
Cited
US2044305A
Cited
US2205142A
Cited
US2199220A
Cited
US2214804A
Cited
US2282405A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-02-15 | 1952-08-16 | 1953-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-02-15 | 1956-08-16 | 1957-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-02-15 | 1960-08-16 | 1961-02-15 | $7700.00 | Window Closed / Lapsed |