Patent US2634385A successfully refreshed from Google Patents.
US2634385A
Expired / Lapsed
US
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Electron tube circuits
Assignee: Westinghouse Air Brake Co
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Filing: 1948-08-24
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Granted: 1953-04-07
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Expires: 1968-08-24
Abstract
No abstract record available.
Inventors
- 👤 Paul N Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:28
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/52
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1243789A
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US1949254A
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US2121760A
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US2213551A
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US2256177A
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US2274992A
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US2361172A
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US2403609A
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US2439680A
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US2541879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-04-06 | 1956-10-06 | 1957-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-04-06 | 1960-10-06 | 1961-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-04-06 | 1964-10-06 | 1965-04-07 | $7700.00 | Window Closed / Lapsed |