US2623931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for detection of frequency differences and apparatus employing same
Assignee: ALERTRONIC PROTECTIVE CORP OF
•
Filing: 1948-12-04
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Granted: 1952-12-30
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Expires: 1968-12-04
Abstract
No abstract record available.
Inventors
- 👤 Samuel M Bagno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:29
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/16; G08B13/1609; G08B13/1618; G08B13/1627
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1490958A
Cited
US1669524A
Cited
US2167007A
Cited
US2382847A
Cited
US2422064A
Cited
US2455639A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-12-30 | 1956-06-30 | 1956-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-12-30 | 1960-06-30 | 1960-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-12-30 | 1964-06-30 | 1964-12-30 | $7700.00 | Window Closed / Lapsed |