Patent US3508191A successfully refreshed from Google Patents.
US3508191A
Expired / Lapsed
US
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Expressway ramp traffic control system
Assignee: LFE Corp
•
Filing: 1967-02-21
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Granted: 1970-04-21
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Expires: 1987-02-21
Abstract
No abstract record available.
Inventors
- 👤 John L Barker
- 👤 Charles L Du Vivier
- 👤 Ludwig R Pallat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:50
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/07; G08G1/075
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3304539A
Cited
US3384869A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-04-20 | 1973-10-20 | 1974-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-04-20 | 1977-10-20 | 1978-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-04-20 | 1981-10-20 | 1982-04-21 | $7700.00 | Window Closed / Lapsed |