Patent US3298386A successfully refreshed from Google Patents.
US3298386A
Expired / Lapsed
US
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System for establishing a plurality of fluid pressure levels
Assignee: Dart Industries Inc
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Filing: 1964-06-15
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Granted: 1967-01-17
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Expires: 1984-06-15
Abstract
No abstract record available.
Inventors
- 👤 Robert M Douglas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:48
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/02; F15B11/028; G; G05; G05D; G05D16/00; G05D16/028; G05D16/04; G05D16/0402; G05D16/0404; G05D16/10; G05D16/101; F15B2211/00; F15B2211/30; F15B2211/305; F15B2211/30505; F15B2211/40; F15B2211/405; F15B2211/40507; F15B2211/50; F15B2211/505; F15B2211/50563; F15B2211/52; F15B2211/528; F15B2211/57; F15B2211/70; F15B2211/71; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2574; Y10T137/2605; Y10T137/2617
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
192 words
IN COMBINATION, A FIRST AND SECOND DIFFERENTIAL PRESSURE REGULATING VALVE, EACH OF SAID VALVES COMPRISING AN ENCLOSED CYLINDRICAL CHAMBER, A SLIDABLE SPOOL VALVE THEREIN, A FIXED RESILIENT FORCE OPPOSING ONE END OF SAID SPOOL AND ABUTTING ON ONE END OF SAID CHAMBER IN SAID FIRST VALVE, A GIVEN RESILIENT FORCE OPPOSING THE OPPOSITE END OF THE SPOOL IN THE SECOND CHAMBER WITH RESPECT TO THE SPOOL IN THE FIRST CHAMBER AND ABUTTING ON SAID OPPOSITE END OF SAID SECOND CHAMBER, A CONDUIT IN EACH OF SAID CHAMBERS FOR PROVIDING A REFERENCE FLUID PRESSURE FOR ACTUATION OF SAID SPOOL VALVES AGAINST AT LEAST THE FIXED RESILIENT FORCES THEREIN, SAID FIRST VALVE BEING PROVIDED WITH AN INLET AND AN OUTLET PORT, SAID INLET PORT BEING MAINTAINED IN A NORMALLY CLOSED POSITION BY THE SPOOL VALVE IN ASSOCIATION WITH THE GIVEN RESILIENT FORCE, SAID SECOND VALVE BEING PROVIDED WITH AN INLET AND AN OUTLET PORT, SAID INLET PORT BEING MAINTAINED IN A NORMALLY OPEN POSITION BY THE SPOOL VALVE IN ASSOCIATION WITH THE GIVEN RESILIENT FORCE AND CONDUIT CONNECTIONS BETWEEN THE OUTLET PORT OF SAID FIRST VALVE AND THE INLET PORT OF SAID SECOND VALVE.
Claim 2
Dependent Claim
192 words
IN COMBINATION, A FIRST AND SECOND DIFFERENTIAL PRESSURE REGULATING VALVE, EACH OF SAID VALVES COMPRISING AN ENCLOSED CYLINDRICAL CHAMBER, A SLIDABLE SPOOL VALVE THEREIN, A FIXED RESILIENT FORCE OPPOSING ONE END OF SAID SPOOL AND ABUTTING ON ONE END OF SAID CHAMBER IN SAID FIRST VALVE, A GIVEN RESILIENT FORCE OPPOSING THE OPPOSITE END OF THE SPOOL IN THE SECOND CHAMBER WITH RESPECT TO THE SPOOL IN THE FIRST CHAMBER AND ABUTTING ON SAID OPPOSITE END OF SAID SECOND CHAMBER, A CONDUIT IN EACH OF SAID CHAMBERS FOR PROVIDING A REFERENCE FLUID PRESSURE FOR ACTUATION OF SAID SPOOL VALVES AGAINST AT LEAST THE FIXED RESILIENT FORCES THEREIN, SAID FIRST VALVE BEING PROVIDED WITH AN INLET AND AN OUTLET PORT, SAID INLET PORT BEING MAINTAINED IN A NORMALLY CLOSED POSITION BY THE SPOOL VALVE IN ASSOCIATION WITH THE GIVEN RESILIENT FORCE, SAID SECOND VALVE BEING PROVIDED WITH AN INLET AND AN OUTLET PORT, SAID INLET PORT BEING MAINTAINED IN A NORMALLY OPEN POSITION BY THE SPOOL VALVE IN ASSOCIATION WITH THE GIVEN RESILIENT FORCE AND CONDUIT CONNECTIONS BETWEEN THE OUTLET PORT OF SAID FIRST VALVE AND THE INLET PORT OF SAID SECOND VALVE.
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) | 1970-01-16 | 1970-07-18 | 1971-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-01-16 | 1974-07-18 | 1975-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-01-16 | 1978-07-18 | 1979-01-17 | $7700.00 | Window Closed / Lapsed |