US3771553A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pilot-operated shut-off valve
Assignee: Individual
•
Filing: 1972-10-30
•
Granted: 1973-11-13
•
Expires: 1992-10-30
Abstract
Abstract An automatic pilot-operated shut-off valve including, in the pilot valve assembly, a pilot piston which controls the operation of oppositely disposed admission and discharge valves. An additional flow control device, in the form of a spool valve, is disposed in the pilot piston for the purpose of restricting the flow between the ends thereof during the discharge valve opening cycle.
Inventors
- 👤 P Huet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:59
CPC Classifications
F; F16; F16K; F16K31/00; F16K31/12; F16K31/36; F16K31/363; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7762
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
In a flow control device including a main fluid operated controller and a pilot valve assembly for controlling the application of control pressure to the actuator of the main controller, the pilot valve assembly comprising a pair of shutoff valve members for respectively controlling admission and discharge of fluid to the pilot valve assembly, said shut-off valves being operated by a pilot valve piston, the improvement comprising: a spool valve including a spool member which restricts flow between the opposite ends of the pilot valve piston during opening of the discharge controlling shut-off valve, the oppositely disposed faces of said spool valve member being respectively subjected to the pressures prevailing in the chambers at said oppositely disposed ends of said pilot valve piston.
Claim 2
Dependent Claim
123 words
In a flow control device including a main fluid operated controller and a pilot valve assembly for controlling the application of control pressure to the actuator of the main controller, the pilot valve assembly comprising a pair of shutoff valve members for respectively controlling admission and discharge of fluid to the pilot valve assembly, said shut-off valves being operated by a pilot valve piston, the improvement comprising: a spool valve including a spool member which restricts flow between the opposite ends of the pilot valve piston during opening of the discharge controlling shut-off valve, the oppositely disposed faces of said spool valve member being respectively subjected to the pressures prevailing in the chambers at said oppositely disposed ends of said pilot valve piston.
Claim 3
Dependent Claim
31 words
The apparatus of claim 1 wherein said pilot valve piston has an axial passage for providing communication between said chambers and wherein said spool valve member normally closes said axial passage.
Claim 4
Dependent Claim
29 words
The apparatus of claim 2 wherein said spool valve member is mounted in said pilot valve piston in a bore which extends transversely of and intersects said axial passage.
Claim 5
Dependent Claim
32 words
The apparatus of claim 3 wherein said pilot valve piston is provided with grooves which extend between opposite ends of said transverse bore and respective opposite ends of said pilot valve piston.
Claim 6
Dependent Claim
21 words
The apparatus of claim 4 wherein said spool valve is spring loaded to the position where said axial passage is closed.
References Cited (Backward Citations)
US2649115A
Cited
US2619109A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |