US2851658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase shifting circuit
Assignee: AT&T Inc
•
Filing: 1953-09-01
•
Granted: 1958-09-09
•
Expires: 1973-09-01
Abstract
No abstract record available.
Inventors
- 👤 Howson Louis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:41
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/16
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1731264A
Cited
US1931873A
Cited
US2018820A
Cited
US2104801A
Cited
US2479817A
Cited
US2541454A
Cited
US2628266A
Cited
US2580803A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-08 | 1962-03-10 | 1962-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-08 | 1966-03-10 | 1966-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-08 | 1970-03-10 | 1970-09-09 | $7700.00 | Window Closed / Lapsed |