US1381451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching system
Assignee: AT&T Inc
•
Filing: 1919-06-24
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Granted: 1921-06-14
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Expires: 1939-06-24
Abstract
No abstract record available.
Inventors
- 👤 Leslie E Coon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:35
CPC Classifications
H; H04; H04Q; H04Q5/00; H04Q5/18; H04Q5/22
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) | 1924-06-13 | 1924-12-13 | 1925-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1928-06-13 | 1928-12-13 | 1929-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1932-06-13 | 1932-12-13 | 1933-06-14 | $7700.00 | Window Closed / Lapsed |