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Patent US3027964A successfully refreshed from Google Patents.
US3027964A
Expired / Lapsed
US
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Loudspeaker
Assignee: Ampex Corp
•
Filing: 1958-06-24
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Granted: 1962-04-03
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Expires: 1978-06-24
Abstract
No abstract record available.
Inventors
- 👤 Jr John D Spragins
- 👤 Leonard T Pockman
- 👤 George A Brettell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:28
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/345
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR473046A
Cited
DE372136C
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US1801521A
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US1770234A
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US1840992A
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US2037187A
Cited
US2001089A
Cited
US1992268A
Cited
US2819771A
Cited
US2820525A
Cited
US2797766A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-04-02 | 1965-10-02 | 1966-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-04-02 | 1969-10-02 | 1970-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-04-02 | 1973-10-02 | 1974-04-03 | $7700.00 | Window Closed / Lapsed |