Patent US1573801A successfully refreshed from Google Patents.
US1573801A
Expired / Lapsed
US
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Trouble-alarm system for radio receiving sets
Assignee: AT&T Inc
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Filing: 1923-10-05
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Granted: 1926-02-23
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Expires: 1943-10-05
Abstract
No abstract record available.
Inventors
- 👤 Bown Ralph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:14
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/52; H03F1/54
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) | 1929-02-22 | 1929-08-24 | 1930-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1933-02-22 | 1933-08-24 | 1934-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1937-02-22 | 1937-08-24 | 1938-02-23 | $7700.00 | Window Closed / Lapsed |