Patent US2740919A successfully refreshed from Google Patents.
US2740919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron lens
Assignee: Farrand Optical Co Inc
•
Filing: 1953-06-25
•
Granted: 1956-04-03
•
Expires: 1973-06-25
Abstract
No abstract record available.
Inventors
- 👤 Gertrude M Fleming
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:47
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/10; H01J37/12
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2410863A
Cited
US2409644A
Cited
US2355795A
Cited
US2431113A
Cited
US2545595A
Cited
US2632115A
Cited
US2520813A
Cited
US2547415A
Cited
US2644906A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-04-03 | 1959-10-03 | 1960-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-03 | 1963-10-03 | 1964-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-03 | 1967-10-03 | 1968-04-03 | $7700.00 | Window Closed / Lapsed |