US2537253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrodynamic telephone receiver
Assignee: Individual
•
Filing: 1946-08-20
•
Granted: 1951-01-09
•
Expires: 1966-08-20
Abstract
No abstract record available.
Inventors
- 👤 Chris S Andersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:14
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1653727A
Cited
US1926187A
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US2104433A
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US2069242A
Cited
US1960016A
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US2031678A
Cited
US2086649A
Cited
US2202886A
Cited
GB532172A
Cited
US2301638A
Cited
US2458158A
Cited
US2482148A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-01-08 | 1954-07-10 | 1955-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-01-08 | 1958-07-10 | 1959-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-01-08 | 1962-07-10 | 1963-01-09 | $7700.00 | Window Closed / Lapsed |