Patent US2420933A successfully refreshed from Google Patents.
US2420933A
Expired / Lapsed
US
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Automatic volume control
Assignee: Wurlitzer Co
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Filing: 1944-08-05
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Granted: 1947-05-20
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Expires: 1964-08-05
Abstract
No abstract record available.
Inventors
- 👤 Frederick G Crawford
- 👤 Edgar A Stroschein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:10
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/22; H03G3/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-05-19 | 1950-11-18 | 1951-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-05-19 | 1954-11-18 | 1955-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-05-19 | 1958-11-18 | 1959-05-20 | $7700.00 | Window Closed / Lapsed |