US3683958A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power transmission
Assignee: Vickers Inc
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Filing: 1970-11-30
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Granted: 1972-08-15
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Expires: 1990-11-30
Abstract
Abstract A fluid pressure relief valve has a pilot chamber, the pressure in which may be varied to determine the level at which the valve will open. A pilot flow path extends from the inlet through the pilot chamber to the outlet and has restrictions, both upstream and downstream, from the pilot chamber. The downstream restriction is pressure compensated to maintain a fixed rate of flow out of the pilot chamber. Upstream there is a fixed restriction and an electromagnetically variable restriction which enables the pressure at which the valve will open to be adjusted electrically to any value over a continuous range.
Inventors
- 👤 John W Curnow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:02
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/02; F16K17/04; F16K17/10; F16K17/105; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/043; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7762; Y10T137/7764
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
148 words
A pilot controlled relief valve comprising a body having an inlet port and an exhaust port, a slidable primary valve controlling flow therebetween, a pilot chamber formed in the body, a slidable piston connected to the primary valve and exposed on one side to inlet pressure, means for establishing a pilot flow from the inlet port to the exhaust port, first and second restriction means for restricting said pilot flow, means for establishing a pressure level in the pilot chamber which varies with the pressure intermediate the two restrictions, electromagnetic means for varying one of the restrictions to modulate the pressure in the pilot chamber to any preselected value, and stabilizing means responsive to the pressure intermediate the two restrictIons for variably biasing the electromagnetic means whereby the pressure level at which the primary valve will open will vary with the degree of energization of the electromagnetic means.
Claim 2
Dependent Claim
148 words
A pilot controlled relief valve comprising a body having an inlet port and an exhaust port, a slidable primary valve controlling flow therebetween, a pilot chamber formed in the body, a slidable piston connected to the primary valve and exposed on one side to inlet pressure, means for establishing a pilot flow from the inlet port to the exhaust port, first and second restriction means for restricting said pilot flow, means for establishing a pressure level in the pilot chamber which varies with the pressure intermediate the two restrictions, electromagnetic means for varying one of the restrictions to modulate the pressure in the pilot chamber to any preselected value, and stabilizing means responsive to the pressure intermediate the two restrictIons for variably biasing the electromagnetic means whereby the pressure level at which the primary valve will open will vary with the degree of energization of the electromagnetic means.
Claim 3
Dependent Claim
23 words
A valve as defined in claim 1 wherein one of the restrictions is pressure compensated to maintain a fixed rate of flow therethrough.
Claim 4
Dependent Claim
27 words
A valve as defined in claim 1 wherein the electromagnetic means includes a flapper blade and the associated restriction is constituted by an orifice facing the blade.
Claim 5
Dependent Claim
126 words
A pilot controlled relief valve comprising a body having an inlet port and an exhaust port, a slidable primary valve controlling flow therebetween, a pilot chamber formed in the body, a slidable piston connected to the primary valve and exposed on one side to inlet pressure and on the other side to pressure in the pilot chamber, a first orifice of variable size connected between the inlet port and the pilot chamber, a pressure compensated flow controller connected between the pilot chamber and the exhaust port, and means for varying the size of the first orifice to thereby modulate the pressure in the pilot chamber to any selected level and thus allow the primary valve to open at a related pressure level in the inlet port.
Claim 6
Dependent Claim
126 words
A pilot controlled relief valve comprising a body having an inlet port and an exhaust port, a slidable primary valve controlling flow therebetween, a pilot chamber formed in the body, a slidable piston connected to the primary valve and exposed on one side to inlet pressure and on the other side to pressure in the pilot chamber, a first orifice of variable size connected between the inlet port and the pilot chamber, a pressure compensated flow controller connected between the pilot chamber and the exhaust port, and means for varying the size of the first orifice to thereby modulate the pressure in the pilot chamber to any selected level and thus allow the primary valve to open at a related pressure level in the inlet port.
Claim 7
Dependent Claim
22 words
A valve as defined in claim 4 wherein an electromagnetically controlled armature is provided to control the size of the first orifice.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |