Patent US6358254B1 successfully refreshed from Google Patents.
US2767249A
Expired / Lapsed
US
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Restricted service telephone system
Assignee: Automatic Electric Laboratories Inc
•
Filing: 1951-07-20
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Granted: 1956-10-16
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Expires: 1971-07-20
Abstract
No abstract record available.
Inventors
- 👤 Duncan N Macdonald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:29
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0008
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1738624A
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US1954967A
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US2206147A
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US2187945A
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US2339376A
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US2333489A
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US2518210A
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US2519867A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-10-16 | 1960-04-16 | 1960-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-10-16 | 1964-04-16 | 1964-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-10-16 | 1968-04-16 | 1968-10-16 | $7700.00 | Window Closed / Lapsed |