Patent US3453396A successfully refreshed from Google Patents.
US3453396A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Key telephone system signaling circuit
Assignee: AT&T Inc
•
Filing: 1966-01-20
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Granted: 1969-07-01
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Expires: 1986-01-20
Abstract
No abstract record available.
Inventors
- 👤 Joseph C Lacey
- 👤 James R Mceowen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:53
CPC Classifications
H; H04; H04M; H04M9/00; H04M9/002; H04M9/003
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2862062A
Cited
US3239610A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-30 | 1972-12-30 | 1973-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-30 | 1976-12-30 | 1977-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-30 | 1980-12-30 | 1981-07-01 | $7700.00 | Window Closed / Lapsed |