Patent US3449681A successfully refreshed from Google Patents.
US3449681A
Expired / Lapsed
US
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Amplifiers with tone controls
Assignee: TLD Inc
•
Filing: 1964-12-18
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Granted: 1969-06-10
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Expires: 1984-12-18
Abstract
No abstract record available.
Inventors
- 👤 David Hafler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:45
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/02; H03G5/04; H03G5/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US513213A
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US2695337A
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US3025472A
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US3059190A
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DE1134141B
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US3221262A
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US3267386A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-09 | 1972-12-09 | 1973-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-09 | 1976-12-09 | 1977-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-09 | 1980-12-09 | 1981-06-10 | $7700.00 | Window Closed / Lapsed |