Patent US3478532A successfully refreshed from Google Patents.
Patent US3810647A successfully refreshed from Google Patents.
Patent US2504335A successfully refreshed from Google Patents.
US2504335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indirectly heated cathode
Assignee: Hartford National Bank and Trust Co
•
Filing: 1947-08-06
•
Granted: 1950-04-18
•
Expires: 1967-08-06
Abstract
No abstract record available.
Inventors
- 👤 Jonker Johan Lodewijk Hendrik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:46
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H05; H05B; H05B3/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2038341A
Cited
AT148796B
Cited
US2226696A
Cited
US2263169A
Cited
US2421039A
Cited
US2445993A
Cited
US2436907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-04-17 | 1953-10-17 | 1954-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-04-17 | 1957-10-17 | 1958-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-04-17 | 1961-10-17 | 1962-04-18 | $7700.00 | Window Closed / Lapsed |