Patent US2223736A successfully refreshed from Google Patents.
US2223736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission circuit
Assignee: AT&T Inc
•
Filing: 1938-03-24
•
Granted: 1940-12-03
•
Expires: 1958-03-24
Abstract
No abstract record available.
Inventors
- 👤 Mertz Pierre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:53
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/38; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/14; H04B3/143
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) | 1943-12-03 | 1944-06-03 | 1944-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-12-03 | 1948-06-03 | 1948-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-12-03 | 1952-06-03 | 1952-12-03 | $7700.00 | Window Closed / Lapsed |