US3474940A - Dispensing valves - Google Patents

Description

0a. 28, 1969 r c. A. HOGG 3,474,940

DISPENSING VALVES Filed July 25, 1967 INVENTOR LHm sTbPHER A. HOGG ATTORNEY United States Patent 3,474,940 DISPENSING VALVES Christopher A. Hogg, Redbridge, Ilford, England, assignor to The British Oxygen Company Limited, a British Company Filed July 25, 1967, Ser. No. 655,820 Claims priority, application Great Britain, July 26, 1966, 33,451/ 66 Int. Cl. B6511 /72, 83/00 US. Cl. ZZZ-402.20 9 Claims ABSTRACT OF THE DISCLOSURE This invention relates to dispensing valves, particularly for dispensing predetermined quantities of fluid from a source of fluid under pressure.

It is known to use a manually-operated valve to control the release of gas from a source of pressurised gas. This suffers from the disadvantage that only coarse control is provided over the quantity of gas dispensed.

The present invention aims at providing a dispensing valve which is efiective to release a predetermined quantity of gas for each operation of the valve.

Accordingly the present invention provides a dispensing valve, which, in its broadest aspect, is as claimed in claim 1 of the appended claims.

The present invention will now be described by way of example with reference to the accompanying diagrammatic drawing, which is an axial sectional view of a valve of the present invention.

The valve is intended, on actuation, to dispense a predetermined quantity of carbon dioxide gas under pressure from a small bulb of the type sold under the trademark Sparklets. Referring to the drawing, a gas bulb 1 containing carbon dioxide under pressure is supported by a bulb holder 2 which is mounted on an inlet body member 3. The mouth of the bulb 1 extends into a bore of body member 3 and engages a resilient annular disc 4. Also located within the bore is a mounted piercing pin 5 and an O-ring 6. The piercing pin 5 is hollow and is adapted to pierce the bulb when the bulb holder is screwed into position. The piercing pin has a tapered end so as to seal the edges of the hole pierced in the bulb thus permitting gas to flow from the bulb only through the interior of the piercing pin. A collar 7 holds the neck of the bulb central during the piercing operation. The inlet body member 3 is formed with an axial passage 25 permitting flow of gas from the piercing pin to a discharge chamber 9 defined by the inlet member 3 and a many body 8. Disposed in passage 25 is a one-way valve having a tapering throat 10 made of a suitably-resilient material, such as nylon, within which is disposed a valve ball 11. The throat 10 is permanently sealed to the inlet member 3. A suitable difierence in pressure across the valve ball tends to cause the ball to block the throat. I

The chamber 9 is in the form of a double, coaxial cylinder having a radially-extending outlet passage 12. The chamber 9 extends beyond this passage and houses an actuator 13. The actuator 13 comprises a push button 14,

3,474,940 Patented Oct. 28, 1969 a detent cam 15, a biassing cam 16, a circumferentiallygrooved forward portion 17, an O-ring seal 18 in the circumferential groove 17 and a probe 19.

A shoulder 20 on the main body limits movement of the actuator 13 away from the discharge chamber 9. In the example illustrated two radially-extending passages 21 open into the bore of the main body inwardly of the shoulder 20, although only one such passage, or three or more, could be provided. Disposed in each of these passages is a ball 22 urged by a helical spring 23 against a biassing cam 16 the actuator 13. Each passage 21 is closed by a screw 24 in a screw-threaded engagement with the wall of the passage. The balls 22, springs 23 and screw 24 constitute adjustable biassing means to allow for alteration of the quantity of gas discharged for the bulb at each operation of the valve.

To enable the valve to dispense through the outlet passage a predetermined quantity of gas from the bulb, the bulb must first be pierced by the piercing pin 5 by screwing the bulb holder 2 fully onto the inlet body member 3. The inlet valve 11, will initially be held in its closed position by pressure of gas from the bulb, so preventing flow of gas beyond the valve, and the actuating member will be in its rest position as shown, with the balls 22 engaging the biassing cam 16. Depression of the push button 14 to initiate dispensing causes the actuator to move axially towards the bulb, the balls 22 riding up the 16, and the O-ring seal 18 passing the outlet passage 12 to seal the chamber 9. During this movement the springs 22 are applying a relatively small axial force to the actuator resisting its movement to its operating position.

Further axial movement of the actuator causes the balls to ride over the peak of the cam 16 onto the detent cam 15. The spring-loaded balls then force the actuator inwardly to its operating position in which the probe 19 unseats the ball 111 of the one-way valve. Gas under pressure then flows into the chamber 9 and exerts a force on the face of the forward portion 17 of the actuator 13. This force increases as the pressure of the gas in the chamber increases until it is sufiicient to overcome the opposing orce provide by the springs and by friction. When this happens the actuator is moved by gas pressure away from the bulb, causing the balls 22 to ride up the detent cam 15, and down the biassing cam 16 to allow the valve ball 11 to reseat on the throat 10 to close the one-way valve. During the final movement of the actuator towards the shoulder 20 the outlet passage 12 is unblocked, so permitting the gas under pressure in the chamber to flow through the outlet passage, until the detent cam 15 again contacts the shoulder 20 in the main body to prevent further backward movement of the actuator. The actuator remains in this position until a further operation is initiated.

It will be noted that to initiate operation it is necessary only to move the push button 14 until the balls 22 ride over the peak between the cams, all further movements being efiected automatically by the mechanism.

Control of the quantity of fluid being dispensed may be obtained not only by changing the volume of the chamber, or the diameter of that part of the chamber which is engaged by the O-ring seal 18 but also b appropriate choice of the axial bias applied to the actuator. Thus the cam shape may be varied as required, or more conveniently the spring load on the balls can be adjusted. The quantity of fluid dispensed can thereby be increased or decreased, subject to the limiting factor that the gas pressure in the chamber cannot exceed the gas pressure in the bulb.

The dispensing valve may be used to dispense predetermined quantities of the gas under pressure in the bulb. By use of a venturi or other nozzle this dispensed gas can entrain other gases, or flowable solids or liquids. In one application the dispensed gas is caused to entrain air in a passage in the vicinity of the heated bit of a desoldering tool. Molten solder may be sucked into this passage each time gas is dispensed by the metering valve.

In another application perfume is entrained with the dispensed gas.

In another application the dispensed gas is used directly to expel a pellet or other missile from a gun barrel, and in a further application the dispensed gas is used to eject a cork from a wine bottle. For the latter application the dispensed gas is introduced into the wine bottle by a hollow needle which pierces the cork. To prevent leakage of gas from the wine bottle past the balls 22 when the actuator is in its operating position a second O-ring should be provided to seal the space around the actuator 13 between the outlet passage 12 and the balls 22. This modification may be used in other applications where it is necessary to prevent leakage back through the dispensing valve of gas under pressure in passage 12.

What is claimed is:

l. A valve for dispensing predetermined quantities of fluid from a source of fluid under pressure, comprising a discharge chamber; a one-way valve arranged when open to admit fluid under pressure into the discharge chamber; an outlet passage leading from the discharge chamber; a longitudinally-movable actuator movable between an operating position in which it opens the oneway valve and seals off the outlet passage, and a rest position in which it permits the one-way valve to close and opens the outlet passage to vent the discharge chamber, means for biasing the actuator towards its rest position, and means effective only when the actuator has been displaced from its rest position, for biasing the actuator longitudinally towards its operating position, the bias being adapted to be overcome when the pressure in the discharge chamber rises sufiiciently to force the actuator towards its resting position.

2. The dispensing valve claimed in claim 1, in which the actuator includes a piston acting as a movable wall of the discharge chamber, and an extension from the piston which is adapted to unseat the valve member of the one-way valve when the piston is in its operating position.

3. The dispensing valve claimed in claim 2, in which the actuator includes a first cam surface acted on by at least one spring-biased ball movable transversely to the axis of movement of the actuator between an inner posi- .4 tion in which it retains the actuator in its operating position, and an outer position which it assumes when the actuator is in its rest position, the or each ball being cammed outwardly by the first cam surface from its inner position by the actuator moving from its operating position towards its rest position.

4. The dispensing valve claimed in claim 3, in which the actuator includes a second cam surface adapted to be engaged alternatively by the or each ball and adapted to apply to the actuator an axial force resisting movement of the actuator from its rest position to its operating position.

5. The dispensing valve claimed in 4, which the or each cam surface is frusto-conical and is adapted to be engaged at two or more uniformly spaced-apart points on its periphery by the biasing means.

6. The dispensing valve claimed in claim 3, in which the biasing force on the or each ball is adjustable.

7. The dispensing valve in claim 6, in which each ball is acted on by a compression spring seated at its end remote from the ball on a member which is movable axially of the path of movement of the respective ball.

8. The dispensing valve claimed in claim 2, in which the piston is sealed to the wall of the discharge chamber by a first O-ring movable with the piston and adjacent to its face.

9. The dispensing valve claimed in claim 1, in which the one-way valve is in communication with means for piercing the wall of a separable container of gas under pressure.

References Cited UNITED STATES PATENTS 1,826,330 10/1931 Thiele 251-297 2,016,113 10/1935 Lambert et al. 222-5 2,209,956 8/ 1940 Chase et al 222-5 2,723,055 11/1955 Beard 222-40225 2,734,774 2/ 1956 Manseau 222-40225 X 3,100,619 8/1963 Berghofer et al. 251-297 X ROBERT B. REEVES, Primary Examiner N. L. STACK, JR., Assistant Examiner US. Cl. X.R.

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