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US421067A
Expired / Lapsed
US
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Art of making cores for electro-magnets
Assignee: —
•
Filing: —
•
Granted: 1890-02-11
•
Expires: 1907-02-11
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:22
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20; H01F1/22; H01F1/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1893-02-10 | 1893-08-12 | 1894-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1897-02-10 | 1897-08-12 | 1898-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1901-02-11 | 1901-08-13 | 1902-02-12 | $7700.00 | Window Closed / Lapsed |