Patent US2921184A successfully refreshed from Google Patents.
US2921184A
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US
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System for signaling by light impulses
Assignee: Individual
•
Filing: 1955-04-26
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Granted: 1960-01-12
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Expires: 1975-04-26
Abstract
No abstract record available.
Inventors
- 👤 Fruengel Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:17
CPC Classifications
G; G08; G08B; G08B5/00; G08B5/22; G08B5/36; G08B5/38
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2227906A
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US2378944A
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US2234329A
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US2304998A
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US2389649A
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US2404696A
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US2403527A
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US2423254A
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US2492247A
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GB732360A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-11 | 1963-07-13 | 1964-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-11 | 1967-07-13 | 1968-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-11 | 1971-07-13 | 1972-01-12 | $7700.00 | Window Closed / Lapsed |