Patent US2490221A successfully refreshed from Google Patents.
US2490221A
Expired / Lapsed
US
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Automatic restricted service telephone system
Assignee: Automatic Electric Laboratories Inc
•
Filing: 1947-01-03
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Granted: 1949-12-06
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Expires: 1967-01-03
Abstract
No abstract record available.
Inventors
- 👤 Clarence E Lomax
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:16
CPC Classifications
H; H04; H04Q; H04Q3/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1256126A
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US1468078A
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US1649494A
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US1567240A
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US1678185A
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US2333039A
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US2375514A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-12-05 | 1953-06-06 | 1953-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-12-05 | 1957-06-06 | 1957-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-12-05 | 1961-06-06 | 1961-12-06 | $7700.00 | Window Closed / Lapsed |