US2774872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase shifting circuit
Assignee: AT&T Inc
•
Filing: 1952-12-17
•
Granted: 1956-12-18
•
Expires: 1972-12-17
Abstract
No abstract record available.
Inventors
- 👤 Howson Louis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 15:52
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/081; H03B; H03B27/00; H03H; H03H11/00; H03H11/02; H03H11/16; H03H11/20
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2406309A
Cited
US2527523A
Cited
US2605425A
Cited
US2526353A
Cited
US2568412A
Cited
US2610297A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-12-18 | 1960-06-18 | 1960-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-12-18 | 1964-06-18 | 1964-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-12-18 | 1968-06-18 | 1968-12-18 | $7700.00 | Window Closed / Lapsed |