Patent US3520525A successfully refreshed from Google Patents.
US3520525A
Expired / Lapsed
US
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Apparatus for delivering air to a blast furnace
Assignee: Beazer East Inc
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Filing: 1967-11-15
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Granted: 1970-07-14
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Expires: 1987-11-15
Abstract
No abstract record available.
Inventors
- 👤 Robert E Zimmermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:10
CPC Classifications
C; C21; C21B; C21B7/00; C21B7/16
Claims Analysis
Total Claims: 0
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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) | 1973-07-13 | 1974-01-12 | 1974-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-13 | 1978-01-12 | 1978-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-13 | 1982-01-12 | 1982-07-14 | $7700.00 | Window Closed / Lapsed |