US2474253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for measuring difference in frequency of alternating currents
Assignee: International Standard Electric Corp
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Filing: 1944-02-24
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Granted: 1949-06-28
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Expires: 1964-02-24
Abstract
No abstract record available.
Inventors
- 👤 Jacobsen Bent Bulow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:26
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/20; G01S1/30; G01R; G01R23/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-06-27 | 1952-12-27 | 1953-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-06-27 | 1956-12-27 | 1957-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-06-27 | 1960-12-27 | 1961-06-28 | $7700.00 | Window Closed / Lapsed |