Patent US2442638A successfully refreshed from Google Patents.
US2442638A
Expired / Lapsed
US
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Thick protective coatings on permanent magnets
Assignee: AT&T Inc
•
Filing: 1943-09-01
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Granted: 1948-06-01
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Expires: 1963-09-01
Abstract
No abstract record available.
Inventors
- 👤 Paul P Cioffi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:33
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/02; H01F7/0205; H01F7/0221
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1595801A
Cited
US1947920A
Cited
GB498714A
Cited
US2240035A
Cited
US2179625A
Cited
US2236277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-06-01 | 1951-12-01 | 1952-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-06-01 | 1955-12-01 | 1956-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-06-01 | 1959-12-01 | 1960-06-01 | $7700.00 | Window Closed / Lapsed |