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US2975239A
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Electromagnetic eraser
Assignee: International Business Machines Corp
•
Filing: 1954-12-24
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Granted: 1961-03-14
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Expires: 1974-12-24
Abstract
No abstract record available.
Inventors
- 👤 Chauncey D Jackson
- 👤 William L Batchelor
- 👤 Donald B Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/004; G11B5/02; G11B5/024; G11B5/127; G11B5/265
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2535480A
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US2766328A
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US2826643A
Cited
US2816176A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-03-13 | 1964-09-12 | 1965-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-03-13 | 1968-09-12 | 1969-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-03-13 | 1972-09-12 | 1973-03-14 | $7700.00 | Window Closed / Lapsed |