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Patent US3507571A successfully refreshed from Google Patents.
US3507571A
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Audio-visual apparatus
Assignee: WALTER F WHITE
•
Filing: 1967-04-03
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Granted: 1970-04-21
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Expires: 1987-04-03
Abstract
No abstract record available.
Inventors
- 👤 Walter F White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:13
CPC Classifications
G; G03; G03B; G03B31/00; G03B31/06; G03B21/00; G03B21/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2705439A
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US3040622A
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US3028789A
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US3187626A
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US3233510A
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US3344709A
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US3381574A
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US3342103A
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US3373654A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-04-20 | 1973-10-20 | 1974-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-04-20 | 1977-10-20 | 1978-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-04-20 | 1981-10-20 | 1982-04-21 | $7700.00 | Window Closed / Lapsed |