US3666374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary molecular vacuum pump
Assignee: ARTHUR PFEIFFER HOCHVAKUUMTECHNIK GMBH
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Filing: 1969-11-13
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Granted: 1972-05-30
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Expires: 1989-11-13
Abstract
Abstract A ROTARY MOLECULAR VACUUM PUMP HAVING EITHER ONE MULTISTAGE COMPRESSION SET, OR A PLURALITY OF MULTI-STAGE COMPRESSION SETS CONNECTED IN PARALLEL, BETWEEN THE PREVACUUM SIDE AND THE HIGH VACUUM SIDE OF THE PUMP HAS AT LEAST ONE GAS INLET WHICH COMMUNICATES WITH THE MULTISTAGE COMPRESSION SET, OR WITH EACH SUCH SET, AT AN INTERMEDIATE POSITION BETWEEN THE PRE-VACUUM AND HIGH VACUUM SIDES OF THE PUMP.
Inventors
- 👤 Willi Becker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:35
CPC Classifications
F; F04; F04D; F04D19/00; F04D19/02; F04D19/04; F04D19/042
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |