US3081936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Check valve for vacuum pump
Assignee: Precision Scientific Co
•
Filing: 1959-11-09
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Granted: 1963-03-19
•
Expires: 1979-11-09
Abstract
No abstract record available.
Inventors
- 👤 Kenneth F Wessling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:06
CPC Classifications
F; F16; F16K; F16K15/00; F16K15/14; F16K15/16; F04; F04C; F04C18/00; F04C18/30; F04C18/34; F04C18/344
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
114 words
IN A VACUUM PUMP A COMBINATION COMPRISING A FRAME, A PUMP UNIT IN SAID FRAME HAVING AN INLET PORT AND AN EXHAUST PORT SURROUNDED BY A LAND PORTION, A CHECK VALVE COVERING SAID EXHAUST PORT, SAID CHECK VALVE INCLUDING AN UPPER LEAF SPRING AND A LOWER LEAF SPRING ARRANGED FLATLY FACE-TO-FACE, SAID LOWER LEAF SPRING BEING SLIGHTLY SPACED AWAY FROM THE LAND SURROUNDING SAID PORT WHEN THE LEAF SPRINGS ARE IN THEIR UNSTRESSED CONDITION, AND SAID LOWER SPRING HAVING AN OPENING THEREIN CENTERED WITH RESPECT TO SAID EXHAUST PORT, A CUSHIONING AND SEALING MEMBER INTERPOSED BETWEEN SAID SPRINGS FOR SEALING THE OPENING IN THE LOWER SPRING WHEN A VACUUM IS DRAWN IN THE INLET
Claim 2
Dependent Claim
114 words
IN A VACUUM PUMP A COMBINATION COMPRISING A FRAME, A PUMP UNIT IN SAID FRAME HAVING AN INLET PORT AND AN EXHAUST PORT SURROUNDED BY A LAND PORTION, A CHECK VALVE COVERING SAID EXHAUST PORT, SAID CHECK VALVE INCLUDING AN UPPER LEAF SPRING AND A LOWER LEAF SPRING ARRANGED FLATLY FACE-TO-FACE, SAID LOWER LEAF SPRING BEING SLIGHTLY SPACED AWAY FROM THE LAND SURROUNDING SAID PORT WHEN THE LEAF SPRINGS ARE IN THEIR UNSTRESSED CONDITION, AND SAID LOWER SPRING HAVING AN OPENING THEREIN CENTERED WITH RESPECT TO SAID EXHAUST PORT, A CUSHIONING AND SEALING MEMBER INTERPOSED BETWEEN SAID SPRINGS FOR SEALING THE OPENING IN THE LOWER SPRING WHEN A VACUUM IS DRAWN IN THE INLET
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-03-18 | 1966-09-17 | 1967-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-03-18 | 1970-09-17 | 1971-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-03-18 | 1974-09-17 | 1975-03-19 | $7700.00 | Window Closed / Lapsed |