US2854228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum furnace useful in the production of metals
Assignee: National Research Corp
•
Filing: 1954-10-14
•
Granted: 1958-09-30
•
Expires: 1974-10-14
Abstract
No abstract record available.
Inventors
- 👤 Arthur E Franks
- 👤 Christopher S Houghton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:51
CPC Classifications
F; F27; F27B; F27B5/00; F27B5/04; F27B14/00; F27B14/04; Y; Y10; Y10S; Y10S266/00; Y10S266/90
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-29 | 1962-03-31 | 1962-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-29 | 1966-03-31 | 1966-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-29 | 1970-03-31 | 1970-09-30 | $7700.00 | Window Closed / Lapsed |