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Patent US3224869A successfully refreshed from Google Patents.
US3224869A
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US
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Method of reducing iron oxide
Assignee: Hydrocarbon Research Inc
•
Filing: 1962-09-20
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Granted: 1965-12-21
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Expires: 1982-09-20
Abstract
No abstract record available.
Inventors
- 👤 Percival C Keith
- 👤 Franklin D Hoffert
- 👤 Harold H Stotler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:09
CPC Classifications
C; C21; C21B; C21B13/00; C21B13/0033; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2562813A
Cited
US2639973A
Cited
US2826487A
Cited
US2995426A
Cited
US2864688A
Cited
US3017254A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-20 | 1969-06-21 | 1969-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-20 | 1973-06-21 | 1973-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-20 | 1977-06-21 | 1977-12-21 | $7700.00 | Window Closed / Lapsed |