Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
253 words
A fluid flow control valve comprising a casing, an inlet leading into said casing, a movable valve element in said casing, first and second means sealing between said element and said casing, such means being spaced apart in the direction in which said element is capable of movement and, together with said casing and said element, bounding a pressure chamber into which said inlet leads, the valve element having a hollow interior and there being an outlet from said hollow interior of the valve element which outlet reduces the area of the movable element on which inlet pressure acts in one direction and which opens into an outlet path leading to the exterior of the valve, said pressure chamber communicating with said outlet path by way of said outlet and said hollow interior, a valve closure member for closing-off said outlet, and said element having a position in which said member closes said outlet to prevent flow from said hollow interior to said outlet path and being capable of movement from said position to establish communication between said hollow interior and said outlet path thereby to open the valve, and the area of one end wall of said chamber, over which area inlet pressure is effective, being different to the area of the other end wall of said chamber over which inlet pressure is effective, and the difference providing a differential area subjected to inlet pressure which compensates for the reduction in inlet pressure subjected area arising from the provision of said outlet.
Claim 2
Dependent Claim
253 words
A fluid flow control valve comprising a casing, an inlet leading into said casing, a movable valve element in said casing, first and second means sealing between said element and said casing, such means being spaced apart in the direction in which said element is capable of movement and, together with said casing and said element, bounding a pressure chamber into which said inlet leads, the valve element having a hollow interior and there being an outlet from said hollow interior of the valve element which outlet reduces the area of the movable element on which inlet pressure acts in one direction and which opens into an outlet path leading to the exterior of the valve, said pressure chamber communicating with said outlet path by way of said outlet and said hollow interior, a valve closure member for closing-off said outlet, and said element having a position in which said member closes said outlet to prevent flow from said hollow interior to said outlet path and being capable of movement from said position to establish communication between said hollow interior and said outlet path thereby to open the valve, and the area of one end wall of said chamber, over which area inlet pressure is effective, being different to the area of the other end wall of said chamber over which inlet pressure is effective, and the difference providing a differential area subjected to inlet pressure which compensates for the reduction in inlet pressure subjected area arising from the provision of said outlet.
Claim 3
Dependent Claim
35 words
A valve according to claim 1, in which each of said first and second means is constituted by a diaphragm having its inner periphery secured to said element and its outer periphery to said casing.
Claim 4
Dependent Claim
36 words
A valve according to claim 1, in which said outlet is constituted by a bore formed in said element and extending from said hollow interior in the direction in which the element is capable of movement.
Claim 5
Dependent Claim
42 words
A valve according to claim 3, in which said element includes diametrically opposed slots and a fixed cross-member extends through the element by way of the slots, there being a valve closure member carried by said cross-member and co-operating with said outlet.
Claim 6
Dependent Claim
58 words
A valve according to claim 1, in which said element includes diametrically opposed slots and a fixed cross-member extends through the element by way of the slots, said outlet being constituted by a passage in said cross-member and there being a valve closure member carried by said element for closing-off communication between said passage and said hollow interior.
Claim 7
Dependent Claim
36 words
A valve according to claim 1, in which said outlet has an area such that said difference in areas equals said area of said outlet so that said element is unaffected by variations in inlet pressure.
Claim 8
Dependent Claim
47 words
A valve according to claim 1, in which said outlet has an area such that said difference in areas is more or less than said area of said outlet whereby a force derived from inlet pressure is exerted on said element which force varies with inlet pressure.
Claim 9
Dependent Claim
52 words
A valve according to claim 1, in which one face of said element is in communication with said outlet so that the element is subjected to back pressure at said outlet and a further face of said element is subjected to a force opposing the force exerted thereon by the back pressure.
Claim 10
Dependent Claim
16 words
A valve according to claim 8, and including a coil spring for exerting the opposing force.
Claim 11
Dependent Claim
80 words
A valve according to claim 1, and comprising spring means for exerting on said element a force tending to move it to the closed position, and a chamber the pressure in which exerts a force tending to move the element to the open position, an inlet to said chamber, a valve for temporarily connecting this chamber to a source of pressure fluid, and a bleed passage from said chamber so that the pressure therein drops over a period of time.