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Patent US2993638A successfully refreshed from Google Patents.
US2993638A
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Electrical vacuum pump apparatus and method
Assignee: Varian Medical Systems Inc
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Filing: 1957-07-24
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Granted: 1961-07-25
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Expires: 1977-07-24
Abstract
No abstract record available.
Inventors
- 👤 Lewis D Hall
- 👤 John C Helmer
- 👤 Robert L Jepsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:34
CPC Classifications
H; H01; H01J; H01J41/00; H01J41/02; H01J41/06; H01J41/12; H01J41/18; H01J41/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2146025A
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US2197079A
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US2460175A
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US2554792A
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US2726805A
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US2755014A
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US2796555A
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US2899605A
Cited
US2850225A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-24 | 1965-01-23 | 1965-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-24 | 1969-01-23 | 1969-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-24 | 1973-01-23 | 1973-07-25 | $7700.00 | Window Closed / Lapsed |