US2489596A - Fluid control valve - Google Patents

Description

Nov. 29, 1949 L. W. SWAIN ET AL FLUID CONTROL VALVE Filed Aug. 20, 1946 Patented Nov. 29, 1949 FLUID. CONTROL 'VALVE Leonardgwalter 'swain and Joseph Anthony Hunt, Redditch, England, assignorsto The Hymatic A Engineering Company Limited, Redditch, Eng- Jami, a British company Application August 20, 1946;1Serial No. 691,830

1 In Great =Britain October 15,1945

1 Claim.

This invention relates to push button operated fluid control valves of the type which supply fluid for the remote operation of a pump, ram or similar device which has an automatic exhaust valve to release the fluid pressure at the conclusion of each operation of the device. If the operator keeps the push button depressed after the conclusion of the operation of the device, pressure fluid will pass freely from the control valve through the remote device to exhaust, with the result that fluid pressure will be lost.

The object of the present invention is to prevent this by providing a simple and effective means for warning the operator both physically and visually that the remote device is being operated and then that the operation has been completed.

The invention consists in a push button operated fluid control valve fitting comprising a push button, a spring loaded fluid control valve, means by which the push button can move the valve from its seat against spring pressure to allow the passage of fluid therethrough to the fluid outlet, and means whereby when the valve is opened the fluid pressure acts to press the push button outwards against spring pressure beyond its normal out-of-service position so giving a physical and visual indication to the operator of the push button that pressure fluid is passing to the control valve fitting outlet and that pressure is maintained to said outlet, the push button returning to its normal position and the valve closing when such pressure is not maintained.

The invention further comprises the arrangement of the push button so that in it normal out-of-service position its face lies flush with the housing in which it is located, the fluid pressure forcing such face outside the housing when fluid pressure is being maintained at the fluid outlet. The invention further comprises the arrangement of a piston in association with the push button and a further piston in association with an intermediate hollow stem between the push button and the valve it opens, the two pistons being in a common cylinder, and the intermediate stem being spring pressed against the push button piston stem, pressure on the push button opening the valve allowing fluid to pass to the fluid outlet and also via thehollow stem to the said cylinder where it tends to move the pistons apart and cause the push button to project from its housing against the manual pressure applied thereto.

The accompanying explanatory drawing is a sectional view of a push button operated fluid control valve constructed in one convenient form in accordance with this invention.

0. indicates the pressure fluid inlet to the fitting and b the outlet connection by which the fluid passes to the device to be operated. A valve 0 loaded by a Spring d prevents fluid passing from a to b. The valve 0 can be pressed .ofl its seat by the end of the stern e of a piston j which may be made of rubber bonded to the flange g on the stem. The latter has a head or flange h at its end which abuts against a similar flange or head 2 upon a stem 7' having a piston k similar to the piston f thereon. The outer end of the stem 7' forms the push button m which is housed within a casing 11. A spring 0 bearing on the internal flange p on the loose sleeve q normally holds the push button m in the position shown, that is with its end face flush with the end of the housing n.

The stem e is hollow so that pressure fluid in the space 1' can pass through the hollow stem to between the stem heads h and i and into the cylinder 8 where it can exert pressure upon the two pistons f and k tending to force them apart. Pressure fluid in the space r can also pass via the passage t to the fluid outlet 1;. The stem 8 is supported by the spring u.

The operation of the control valve is as follows:When the push button m is depressed below the level of the end of the housing n, the head i of the stem 7' presses against the head h of the stem e, so that the lower end of the latter pushes the valve 0 off its seat and fluid passes from the inlet a to the space 1' and thence to the outlet b via the passage t, and also through the interior of the stem 6 to the cylinder 8 between the pistons f and k. The outer ends of the pistons are open to atmospheric pressure. The pistons tend to move apart, which causes a considerable counter pres-sure to be exerted against the operators finger upon the push button, resulting in the push button protruding from the housing 11.. This gives a visual indication that the valve 0 is open and that fluid pressure is passing such valve to the outlet b. The operator also fee1s the counter pressure.

When the appliance being fed from the connection b has completed its operation and has opened its exhaust port, the pressure in the space 1 will fall, which will enable the spring 0 to return the push button to its original position flush with the housing n as shown and allow the valve 0 to close under the pressure of the spring 41. The return of the pus-h button m to the position shown indicates that the valve 0 is closed.

What we claim is:

A push button operated fluid control valve comprising, in combination, a housing, a push button in said housing, a spring loading said push button so that it does not normally project from the housing, a cylinder open at its ends to atmosphere, a piston in said cylinder with its rod connectedto said push button, a further piston in said cylinder, a hollow rod carrying said further piston and abutting against the rod of the first piston, with means allowing the pressure within the hollow rod to pass into the cylinder between the two pistons, a spring external to the cylinder acting on the further piston rod and pressing the piston rods together, an inlet valve, a spring holding said valve on its seat, the end of said further piston rod being adapted to press said inlet valve oif its seat when the pushbutton is pressed into its housing, a space around the end of said further piston rod communicating with the hollow interior of said rod and with the fluid outlet, pressure in said space forcing the push button outwards from the housing through the medium of the hollow piston rod and the piston connected to the push button.

1 LEONARD WALTER. SWAIN. JOSEPH ANTHONY HUNT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 210,663 Brand Dec. 10, 1878 1,427,821 Keith Sept. 5, 1922

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