Patent US3028927A successfully refreshed from Google Patents.
US3028927A
Expired / Lapsed
US
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Dual coaxial speaker
Assignee: Ling Temco Vought Inc
•
Filing: 1958-07-28
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Granted: 1962-04-10
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Expires: 1978-07-28
Abstract
No abstract record available.
Inventors
- 👤 Sidney E Levy
- 👤 Blumenfeld Arthur
- 👤 Bernard C Sharp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:38
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1737864A
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US2058555A
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US2214591A
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US2545961A
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FR1024291A
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US2692913A
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US2746558A
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US2856467A
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GB742889A
Cited
US2858377A
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US2857478A
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US2857012A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-04-09 | 1965-10-09 | 1966-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-04-09 | 1969-10-09 | 1970-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-04-09 | 1973-10-09 | 1974-04-10 | $7700.00 | Window Closed / Lapsed |