Patent US2540873A successfully refreshed from Google Patents.
US2540873A
Expired / Lapsed
US
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Auxiliary voice screen for telephone mouthpieces
Assignee: Individual
•
Filing: 1949-04-01
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Granted: 1951-02-06
•
Expires: 1969-04-01
Abstract
No abstract record available.
Inventors
- 👤 Florman Irving
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:00
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/02; H04M1/19
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US887124A
Cited
GB191323601A
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US1227363A
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US1294197A
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US1474100A
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US1529537A
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US1666220A
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US2131820A
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US2245724A
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US2390488A
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US2456346A
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US2478783A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-05 | 1954-08-07 | 1955-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-05 | 1958-08-07 | 1959-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-05 | 1962-08-07 | 1963-02-06 | $7700.00 | Window Closed / Lapsed |