Patent US1998840A successfully refreshed from Google Patents.
US1998840A
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Magnetic material and method of treatment thereof
Assignee: AT&T Inc
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Filing: 1934-03-13
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Granted: 1935-04-23
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Expires: 1954-03-13
Abstract
No abstract record available.
Inventors
- 👤 Victor E Legg
- 👤 Peterson Eugene
- 👤 Leishman R Wrathall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:30
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/78; B; B22; B22F; B22F3/00; B22F3/24; C21D8/00; C21D8/12; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49075
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) | 1938-04-22 | 1938-10-22 | 1939-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-04-22 | 1942-10-22 | 1943-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-04-22 | 1946-10-22 | 1947-04-23 | $7700.00 | Window Closed / Lapsed |