US2147728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase changer
Assignee: AT&T Inc
•
Filing: 1937-07-03
•
Granted: 1939-02-21
•
Expires: 1957-07-03
Abstract
No abstract record available.
Inventors
- 👤 William T Wintringham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:58
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/16; H03H11/20; G; G01; G01S; G01S1/00; G01S1/02; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/30; H03H7/00; H03H7/18; H03H7/20; H03H7/21
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) | 1942-02-20 | 1942-08-22 | 1943-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-02-20 | 1946-08-22 | 1947-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-02-20 | 1950-08-22 | 1951-02-21 | $7700.00 | Window Closed / Lapsed |