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US2813929A
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Automatic signalling system
Assignee: Government of Netherlands
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Filing: 1952-10-24
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Granted: 1957-11-19
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Expires: 1972-10-24
Abstract
No abstract record available.
Inventors
- 👤 Oberman Roelof Maarten Marie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:13
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004; G; G21; G21C; G21C1/00; G21G; G21G1/00; G21G1/04; G21G1/06; G21G1/08; Y; Y02; Y02E; Y02E30/00; Y02E30/30
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) | 1960-11-18 | 1961-05-20 | 1961-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-11-18 | 1965-05-20 | 1965-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-11-18 | 1969-05-20 | 1969-11-19 | $7700.00 | Window Closed / Lapsed |