US1928610A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency signaling system
Assignee: AT&T Inc
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Filing: 1925-12-24
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Granted: 1933-10-03
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Expires: 1945-12-24
Abstract
No abstract record available.
Inventors
- 👤 Herman A Affel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:40
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/54; H04B3/56
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) | 1936-10-02 | 1937-04-03 | 1937-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-10-02 | 1941-04-03 | 1941-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-10-02 | 1945-04-03 | 1945-10-03 | $7700.00 | Window Closed / Lapsed |