US2421026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Delay device
Assignee: AT&T Inc
•
Filing: 1943-07-08
•
Granted: 1947-05-27
•
Expires: 1963-07-08
Abstract
No abstract record available.
Inventors
- 👤 John A Hall
- 👤 Warren P Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:23
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/30; H03H9/36
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1111463A
Cited
GB357957A
Cited
US1981999A
Cited
US2104811A
Cited
US2169304A
Cited
US2266658A
Cited
US2263902A
Cited
FR846812A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-05-26 | 1950-11-25 | 1951-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-05-26 | 1954-11-25 | 1955-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-05-26 | 1958-11-25 | 1959-05-27 | $7700.00 | Window Closed / Lapsed |