Patent US1562769A successfully refreshed from Google Patents.
Patent US2799576A successfully refreshed from Google Patents.
US2799576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for operating shaft blast furnaces
Assignee: Strikfeldt & Co W
•
Filing: 1954-11-08
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Granted: 1957-07-16
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Expires: 1974-11-08
Abstract
No abstract record available.
Inventors
- 👤 Gumz Wilhelm
- 👤 Becker Ernst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:48
CPC Classifications
C; C21; C21B; C21B5/00; C21B5/06; Y; Y02; Y02P; Y02P10/00; Y02P10/25
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
43 words
A METHOD OF OPERATING A SHAFT FURNACSE FOR SMELTING ORE AND IRON AND PROVIDED WITH DIRECT FIRED AIR HEATER, CONSISTING IN LEADING THE COOLED FLUE GASES LEAVING THE AIR HEATER BACK INTO THE CHARGE COLUMN OF THE SHAFT FURNACE ABOVE THE COMBUSTION ZONE.
Claim 2
Independent Claim
43 words
A METHOD OF OPERATING A SHAFT FURNACSE FOR SMELTING ORE AND IRON AND PROVIDED WITH DIRECT FIRED AIR HEATER, CONSISTING IN LEADING THE COOLED FLUE GASES LEAVING THE AIR HEATER BACK INTO THE CHARGE COLUMN OF THE SHAFT FURNACE ABOVE THE COMBUSTION ZONE.
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) | 1960-07-15 | 1961-01-14 | 1961-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-07-15 | 1965-01-14 | 1965-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-07-15 | 1969-01-14 | 1969-07-16 | $7700.00 | Window Closed / Lapsed |