Patent US3421887A successfully refreshed from Google Patents.
US3421887A
Expired / Lapsed
US
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Process for producing a magnesium-containing spherical graphite cast iron having little dross present
Assignee: Kusaka Rare Metal Products Co Ltd
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Filing: 1967-05-29
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Granted: 1969-01-14
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Expires: 1987-05-29
Abstract
No abstract record available.
Inventors
- 👤 Kazuji Kusaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:55
CPC Classifications
C; C22; C22C; C22C37/00; C22C37/04; C21; C21C; C21C1/00; C21C1/10; C21C7/00; C22C35/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2622022A
Cited
US2750284A
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US2948605A
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US2814559A
Cited
US2821473A
Cited
US2822266A
Cited
US2932567A
Cited
US2922713A
Cited
US2980530A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-14 | 1972-07-15 | 1973-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-14 | 1976-07-15 | 1977-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-14 | 1980-07-15 | 1981-01-14 | $7700.00 | Window Closed / Lapsed |