US2867690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Auxiliary sender circuit
Assignee: AT&T Inc
•
Filing: 1956-07-13
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Granted: 1959-01-06
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Expires: 1976-07-13
Abstract
No abstract record available.
Inventors
- 👤 Charles O Parks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:52
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004
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) | 1962-01-05 | 1962-07-07 | 1963-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-05 | 1966-07-07 | 1967-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-05 | 1970-07-07 | 1971-01-06 | $7700.00 | Window Closed / Lapsed |