Patent US6128559A successfully refreshed from Google Patents.
US2494594A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Audio fatigue unit
Assignee: Individual
•
Filing: 1944-11-16
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Granted: 1950-01-17
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Expires: 1964-11-16
Abstract
No abstract record available.
Inventors
- 👤 Wilbert A Swank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:11
CPC Classifications
G; G10; G10H; G10H5/00; G10H5/10; G10L; G10L25/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1994902A
Cited
US2040439A
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US2140840A
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US2233948A
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US2252189A
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US2369418A
Cited
US2354699A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-01-16 | 1953-07-18 | 1954-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-01-16 | 1957-07-18 | 1958-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-01-16 | 1961-07-18 | 1962-01-17 | $7700.00 | Window Closed / Lapsed |