US1896487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calling circuit
Assignee: AT&T Inc
•
Filing: 1930-04-18
•
Granted: 1933-02-07
•
Expires: 1950-04-18
Abstract
No abstract record available.
Inventors
- 👤 Robert D Gibson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:05
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/54; H04B3/544
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) | 1936-02-07 | 1936-08-08 | 1937-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-02-07 | 1940-08-08 | 1941-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-02-07 | 1944-08-08 | 1945-02-07 | $7700.00 | Window Closed / Lapsed |