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Patent US2884490A successfully refreshed from Google Patents.
US2884490A
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US
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Telephone intercommunication system
Assignee: Individual
•
Filing: 1956-09-12
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Granted: 1959-04-28
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Expires: 1976-09-12
Abstract
No abstract record available.
Inventors
- 👤 Trachsel Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:02
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2057868A
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US2068726A
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US2037221A
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US2244920A
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US2258853A
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US2402446A
Cited
US2542079A
Cited
US2787667A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-27 | 1962-10-27 | 1963-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-27 | 1966-10-27 | 1967-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-27 | 1970-10-27 | 1971-04-28 | $7700.00 | Window Closed / Lapsed |