US2199278A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron discharge device
Assignee: AT&T Inc
•
Filing: 1939-10-26
•
Granted: 1940-04-30
•
Expires: 1959-10-26
Abstract
No abstract record available.
Inventors
- 👤 Donald H Black
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:10
CPC Classifications
H; H01; H01J; H01J43/00; H01J43/02; H01J43/025; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/10; H03K4/12; H03K4/18
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) | 1943-04-30 | 1943-10-30 | 1944-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-04-30 | 1947-10-30 | 1948-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-04-30 | 1951-10-30 | 1952-04-30 | $7700.00 | Window Closed / Lapsed |