Patent US2931958A successfully refreshed from Google Patents.
US2931958A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semi-conductor devices
Assignee: National Research Development Corp UK
•
Filing: 1955-04-19
•
Granted: 1960-04-05
•
Expires: 1975-04-19
Abstract
No abstract record available.
Inventors
- 👤 James B Arthur
- 👤 Bardsley William
- 👤 Brown Michael Anton Ce Salkeld
- 👤 Gibson Alan Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:56
CPC Classifications
H; H10; H10D; H10D99/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-04-05 | 1963-10-05 | 1964-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-05 | 1967-10-05 | 1968-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-05 | 1971-10-05 | 1972-04-05 | $7700.00 | Window Closed / Lapsed |