US2492381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for timing telephone calls
Assignee: AT&T Inc
•
Filing: 1945-04-21
•
Granted: 1949-12-27
•
Expires: 1965-04-21
Abstract
No abstract record available.
Inventors
- 👤 Sanford F Dunning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:34
CPC Classifications
H; H04; H04M; H04M15/00; H04M15/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2400085A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-12-26 | 1953-06-27 | 1953-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-12-26 | 1957-06-27 | 1957-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-12-26 | 1961-06-27 | 1961-12-27 | $7700.00 | Window Closed / Lapsed |