Patent US2521623A successfully refreshed from Google Patents.
US2521623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording and reproducing
Assignee: Brush Development Co
•
Filing: 1945-02-06
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Granted: 1950-09-05
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Expires: 1965-02-06
Abstract
No abstract record available.
Inventors
- 👤 Jr John P Arndt
- 👤 Jr John E Shomer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:22
CPC Classifications
—
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE457282C
Cited
US2351003A
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US2334726A
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US2378388A
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US2370133A
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US2343099A
Cited
US2378383A
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US2439446A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-09-04 | 1954-03-06 | 1954-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-04 | 1958-03-06 | 1958-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-04 | 1962-03-06 | 1962-09-05 | $7700.00 | Window Closed / Lapsed |