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Patent US2797320A successfully refreshed from Google Patents.
US2797320A
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Electrical signalling systems
Assignee: British Telecommunications PLC
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Filing: 1953-05-26
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Granted: 1957-06-25
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Expires: 1973-05-26
Abstract
No abstract record available.
Inventors
- 👤 Beaufoy Raymond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:28
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/04; H; H03; H03K; H03K17/00; H03K17/51; H03K17/54; H04; H04L; H04L25/00; H04L25/02; H04L25/06; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/32; H04Q1/36; H04Q3/00; H04Q3/42
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) | 1960-06-24 | 1960-12-24 | 1961-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-06-24 | 1964-12-24 | 1965-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-06-24 | 1968-12-24 | 1969-06-25 | $7700.00 | Window Closed / Lapsed |