US3389897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of operating a hot blast cupola furnace
Assignee: Gesellschaft fur Huttenwerksanlagen M B H
•
Filing: 1965-10-12
•
Granted: 1968-06-25
•
Expires: 1985-10-12
Abstract
No abstract record available.
Inventors
- 👤 Tunder Siegfried
- 👤 Schefels Gerhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:20
CPC Classifications
F; F27; F27B; F27B1/00; F27B1/10; F27B1/22; Y; Y10; Y10S; Y10S261/00; Y10S261/09
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) | 1971-06-25 | 1971-12-25 | 1972-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-06-25 | 1975-12-25 | 1976-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-06-25 | 1979-12-25 | 1980-06-25 | $7700.00 | Window Closed / Lapsed |