US2501032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet assembly for electrodynamic loud-speakers
Assignee: RCA Corp
•
Filing: 1945-11-30
•
Granted: 1950-03-21
•
Expires: 1965-11-30
Abstract
No abstract record available.
Inventors
- 👤 Fred J Harbaugh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:35
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/06; H04R9/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1864809A
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GB372809A
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US1847702A
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GB389898A
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GB397617A
Cited
GB412552A
Cited
US2029282A
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FR827276A
Cited
US2312238A
Cited
GB552328A
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US2395166A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-03-20 | 1953-09-19 | 1954-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-03-20 | 1957-09-19 | 1958-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-03-20 | 1961-09-19 | 1962-03-21 | $7700.00 | Window Closed / Lapsed |