Patent US2604520A successfully refreshed from Google Patents.
US2604520A
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US
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Polyphase supply circuit and frequency meter
Assignee: Kollsman Instrument Corp
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Filing: 1948-11-05
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Granted: 1952-07-22
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Expires: 1968-11-05
Abstract
No abstract record available.
Inventors
- 👤 Jr John H Andresen
- 👤 Kasner Edward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:57
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1068111A
Cited
US1762725A
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US1894455A
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US2211543A
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US2232789A
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US2425811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-07-22 | 1956-01-21 | 1956-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-07-22 | 1960-01-21 | 1960-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-07-22 | 1964-01-21 | 1964-07-22 | $7700.00 | Window Closed / Lapsed |