Patent US3556681A successfully refreshed from Google Patents.
US3556681A
Expired / Lapsed
US
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High vacuum pump with air jet having automatic cut-in valve
Assignee: Individual
•
Filing: 1969-02-03
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Granted: 1971-01-19
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Expires: 1989-02-03
Abstract
Abstract A HIGH VACUUM PUMP PROVIDED WITH AN AIR JET THAT IS AUTOMATICALLY CUT INTO THE SYSTEM UPON THE ATTAINMENT OF A PREDETERMINED VACUUM LEVEL. THE VALVE ARRANGEMENT INCLUDES PNEUMATICALLY OPERATED VALVES WHICH BRING THE AIR JET ASSEMBLY INTO OPERATION, USING THE VACUUM PUMP AS A SECOND STAGE. THE PNEUMATIC VALVES ARE MADE OPERATIVE BY A VACUUM SWITCH CONTROLLING A SOLENOID AND A DOUBLE-ACTING CONTROL VALVE.
Inventors
- 👤 Irving C Jennings
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:50
CPC Classifications
F; F04; F04C; F04C28/00; F04C28/24; F04C28/26; F04F; F04F5/00; F04F5/44; F04F5/48; F04F5/52
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) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |