US1224374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-way, two-wire trunk for multi-office automatic exchange systems.
Assignee: AT&T Inc
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Filing: 1917-03-03
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Granted: 1917-05-01
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Expires: 1937-03-03
Abstract
No abstract record available.
Inventors
- 👤 Charles L Goodrum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:21
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0016
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) | 1920-04-30 | 1920-10-30 | 1921-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1924-04-30 | 1924-10-30 | 1925-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1928-04-30 | 1928-10-30 | 1929-05-01 | $7700.00 | Window Closed / Lapsed |