US3385935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Key telephone system
Assignee: AT&T Inc
•
Filing: 1964-10-19
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Granted: 1968-05-28
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Expires: 1984-10-19
Abstract
No abstract record available.
Inventors
- 👤 Harold P Anderson
- 👤 David T Davis
- 👤 Jr Lawrence A Hohmann
- 👤 Lloyd L Maul
- 👤 James R Mceowen
- 👤 Jr Henry A Meise
- 👤 George W Well
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:36
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04Q3/52; H04Q3/521; H04M; H04M9/00; H04M9/002; H04M9/005
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-05-28 | 1971-11-27 | 1972-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-05-28 | 1975-11-27 | 1976-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-05-28 | 1979-11-27 | 1980-05-28 | $7700.00 | Window Closed / Lapsed |