Patent US3538570A successfully refreshed from Google Patents.
US3538570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic dispenser cathode
Assignee: OTTO G KOPPIUS
•
Filing: 1968-02-28
•
Granted: 1970-11-10
•
Expires: 1988-02-28
Abstract
No abstract record available.
Inventors
- 👤 Otto G Koppius
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:22
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042; H01J9/047; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/28
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |