US2401779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Summing amplifier
Assignee: AT&T Inc
•
Filing: 1941-05-01
•
Granted: 1946-06-11
•
Expires: 1961-05-01
Abstract
No abstract record available.
Inventors
- 👤 Jr Karl D Swartzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:08
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/34; H03F1/36; G; G06; G06G; G06G7/00; G06G7/12; G06G7/14
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1949-06-10 | 1949-12-10 | 1950-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1953-06-10 | 1953-12-10 | 1954-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1957-06-10 | 1957-12-10 | 1958-06-11 | $7700.00 | Window Closed / Lapsed |