US2764636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dial telephone system arranged for operator or machine announcement on intercepted calls
Assignee: AT&T Inc
•
Filing: 1952-02-27
•
Granted: 1956-09-25
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Expires: 1972-02-27
Abstract
No abstract record available.
Inventors
- 👤 Preston R Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:33
CPC Classifications
H; H04; H04Q; H04Q3/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2385968A
Cited
US2021286A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-09-25 | 1960-03-26 | 1960-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-09-25 | 1964-03-26 | 1964-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-09-25 | 1968-03-26 | 1968-09-25 | $7700.00 | Window Closed / Lapsed |