Patent US2859453A successfully refreshed from Google Patents.
US2964597A
Expired / Lapsed
US
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Loudspeaker magnetic field structure
Assignee: RCA Corp
•
Filing: 1954-12-10
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Granted: 1960-12-13
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Expires: 1974-12-10
Abstract
No abstract record available.
Inventors
- 👤 Roger E Hamson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:35
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/02; H04R9/025; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49908; Y10T29/49925; Y10T29/49934; Y10T29/49938
Claims Analysis
Total Claims: 0
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US2517727A
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US2769942A
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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) | 1963-12-13 | 1964-06-13 | 1964-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-12-13 | 1968-06-13 | 1968-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-12-13 | 1972-06-13 | 1972-12-13 | $7700.00 | Window Closed / Lapsed |