GB2026135A - Flow control device - Google Patents

Abstract

The device comprises a body having an inlet and outlet port 11, 12 with a valve member 17 controlling the flow therebetween and a reservoir 29 communicating with the inlet port via bleed means (28 or 162) adjustable manually or automatically by flow pressure, a wall of the reservoir being formed by a flexible member 14 and means operably interconnecting the flexible member and the valve member. When sufficient pressure is established in the reservoir by the fluid bled thereinto the valve member 17 closes, the period of time taken before the valve 17 closes being determined by adjustment of the bleed means. An air vent 62 is closed automatically by the rising level in reservoir 29 prior to pressure being established therein. A normally closed dump valve 43 opens automatically when main inlet pressure is relieved. Several devices may be connected in series to automatically operate in sequence. <IMAGE>

Description

SPECIFICATION Improvements in and relating to fluid flow control devices This invention relates to an improved fluid flow control device which may be used to terminate the flow of fluid after a predetermined interval of time. It is also to be understood that subject to other conditions, such as pressure being generally uniform, duration of flow and quantity of fluid are sunonymous.

There are of course an infinite number of applications for fluid flow control devices, and although throughout the specification particular reference will be made to use of the device for controlling the flow of water, in domestic and agricultural fields, the invention is clearly not limited to water or these specific applications.

The known liquid flow control devices fall basically into two groups, the first being those having an electrical or mechanical timing mechanism which permits the flow for a preselected time, controlled by the timing mechanism. In the other group, liquid is bled from the main liquid stream through a controlled opening into a chamber, the period of operation of the device being regulated in accordance with the quantity of liquid in the chamber. It will be appreciated that the time taken for the required amount of liquid to enter the chamber is dependent upon the size of the chamber and the rate at which the liquid may by-pass from the main stream into the chamber.

The present invention relates to a flow control device of the latter type, and the object of the invention is to provide such a device which is more reliable in its operation than the currently known devices of this type, and which is suitable for high volume inexpensive manufacture.

With this object in view there is provided a fluid flow control device comprising a body having inlet and outlet ports and a main conduit providing a passage for fluid from the inlet to the outlet port, a main valve member operable to interrupt fluid flow communication between said inlet and outlet ports, a fluid reservoir, adjustable bleed means communicating the main conduit on the inlet side of the main valve member with the reservoir to divert portion of the fluid entering the body into the reservoir, means to actuate said main valve member in response to the pressure in said reservoir to interrupt communication between said inlet and outlet ports upon a predetermined pressure difference existing between the main conduit and the reservoir.

Conveniently the means to actuate the main valve member include a diaphragm forming one wall of the reservoir. The diaphragm and the main valve member are arranged so the deflection of the diaphragm will move the main valve member between positions to permit and interrupt respectively the flow through the outlet port. Preferably there is provided a secondary conduit communicating with the main conduit through a by-pass port. The main valve member operates to close the by-pass port when the outlet port is open and vice versa.

There is preferably provided an air bleed to permit air in the reservoir to escape as the fluid enters, and air to enter when the reservoir is being emptied. An air bleed valve assembly may comprise a port in the reservoir wall and bleed valve member arranged to close the port upon the fluid in the reservoir reaching a predetermined level, and opening upon the fluid falling below said level. It is convenient for the bleed valve member to be biased towards the open position, and to be buoyant so that the tendency of the valve member to float on the rising liquid will effect the closing of the port. The level of fluid in the reservoir at which the bleed valve closes is preferably below the level which fills the reservoir with fluid.The selection of such a level results in a quantity of air being trapped in the reservoir that is then compressed as further fluid enters through the bleed valve. Accordingly when the diaphragm de flecks to open the main valve member the air in the reservoir will expand. Although the pressure on the diaphragm will decrease on deflection of the diaphragm, it will remain substantially higher than would result if the reservoir were filled with liquid. In this manner a smoother closing of the main valve member is achieved and particularly "hammering" by the valve member is avoided.

Also it has been found that a restricting of the air bleed port so as to maintain a back pressure in the reservoir during the entry of fluid through the bleed valve assists in the regulation of the flow of fluid into the reservoir, particularly when the flow rate is small.

Between each cycle of operation of the control device it is necessary to drain the fluid from the reservoir so that firstly the outlet port is opened and secondly fluid may again be bled into the reservoir to determine the period of flow through the outlet port. The draining of the reservoir is achieved by the provision of a dump valve in the lower part of the reservoir so that when the dump valve is open the fluid is discharged by gravity to empty the reservoir.

The dump valve is preferably automatic in operation to be closed by means responsive to the pressure in the main conduit exceeding a predetermined value and to open when said pressure falls below that value. This may be achieved by the dump valve being operated by a diaphragm which is subjected to the pressure in the main conduit.

In an alternative construction, the diaphragm may be in the form of a liner of flexible material sealed about the perimeter of the reservoir and contoured similarly to the interior of the reservoir. The fluid bled from the main conduit enters the reservoir between the reservoir wall and the flexible'liner. As the reservoir fills with liquid the liner rises on the fluid in folds or pleats until portion of the liner forms an interface between the fluid and an actuating head on a stem of the main valve. The pressure of fluid in the reservoir is thus applied to the main valve to move it to close the outlet port.

The adjustable bleed means may be of any one of a variety of forms of adjustable valve suitable for small flows. The adjustable valve may be a simple tapered needle operating in a port with or without an associated capillary to provide viscous drag. Alterna tively a screw type valve may be used where the fluid passes along a helical path the effective length and/or cross-section of which may be varied and hence adjusting the flow by varying the viscous drag.

The invention will be more readily understood from the following description of one practical arrangement of the flow-control device as illustrated in and with reference to the accompanying drawings.

In the drawings Figure 1 is a plan view of the control device Figure 2 is a sectional elevation of the control device taken along line 2-2 in Figure 1, Figure 3 is a partial sectional viewtaken along line 3-3 in Figure 1.

Figure 4 is a plan view of an alternative embodiment of the control device, Figure 5 is a sectional elevation along line 5-5 in Figure 4, Figure 6is a partial sectional view along line 6-6 in Figure 4, Figure 7is a sectional view along line 7-7 in Figure 6.

The control device as shown in the drawings is constructed for use in controlling the flow of water, particularly in applications such as watering gardens, and a number of the devices may be connected in series to operate in sequence commencing with the device nearest to the water source.

Referring now the the drawings, the control device comprises a body 10 having an inlet port 11 and an outlet delivery port 12, and a reservoir 13 secured to the body 10 with the periphery of the diaphragm 14 clamped between the body and reservoir.

The inlet port 11 communicates with the outlet port 12 via the passage 15 and the chamber 16. The shut-off valve 17, located in the chamber 16, may sealably co-operate with the outlet valve seat 18 or the by-pass valve seat 19 as described hereinafter.

The by-pass chamber 20 communicates with the passage 21 and the by-pass port 22. The by-pass port may form a communication with another control device, or with auxiliary equipment, or if the control device is used alone, the by-pass port 22 will be closed by a suitable cap, not shown. The annular shaped filter chamber 25, communicates with the passage 15 by the filter pasage 26, and contains the filter element 25a.

The filter chamber 25 is formed by complementary upper and lower sections 30 and 31 each having an outer peripheral flange 32 and 33 respectively. The upper and lower filter chamber sections are formed with inter-fitting shoulders and recesses in the areas 34 and 34a so that, when the sections are assembled in a co-axial relation with one another and with the body 10 and reservoir 13, the recesses and shoulders in the areas 34 and 34a form seals between the upper and lower sections 30 and 31, thus to form the continuous annular shaped filter chamber 25. The filter element 25a is also of an annular shape and the inner and outer marginal areas thereof are held between the inter-fitting recess and shoulders in the areas 34 and 34a. The filter element 25a is thus conveniently held in position to divide the filter chamber into an unfiltered and filtered area.The gripping of the filter between the recesses and shoulders can also assist in providing the necessary seal between the upper and lower sections 30 and 31 of the filter chambers The filter passage 26 in the body 10 aligns with the passage 26a in the upper section 30 of the filter chamber to permit water to flow from the passage 15 into the filter chamber 25 upstream of the filter element 25a. An O-ring seal is located about the periphery of the passage 26 to provide a seal between the body 10 and the upper section 30 of the filter chamber when the control device is assembled.

A continuous circular or annular duct 35 is formed between the flanges 32 and 33 of the upper and lower sections 30 and 31 of the filter chamber, and communicates with the interior of the filter chamber on the downstream side of the filter elements through a number of peripherally spaced ports 36 provided in the lower section 31 of the filter chamber. The liquid flow control passage 27 is formed by aligning apertures in the reservoir 13, the upper and lower filter section flanges 32 and 33, the body 10, and the gaskets and diaphragm located between these respective components. This can be clearly seen in Figure 3 of the drawings.

The lower end of the control passage 27 communicates via the duct 27a with the interior 29 of the reservoir and also communicates with the annular passage 35 by a break in the gasket located between the flanges 32 and 33. The control screw 28 threadably engages the bore 28a in the body 10, so that the position of the tapered end portion 28b of the control screw can be moved axially in the control passage 27 to vary the rate of flow of liquid from the filter chamber 25 into the reservoir. The O-ring seal assembly 28c is provided on the control screw 28 to prevent the escape of water through the upper face of the body 10.

The air bleed valve assembly 60 comprises a valve port member 61 fitted in the wall of the reservoir 13 and having a port 62 therein providing a communication between the interior of the reservoir 13 and atmosphere. The valve member 63 is in the form of a float supported on a resilient leg 64 attached to portion of the wall of the reservoir 13. The conical end portion 63a of the valve member 63 axially aligns with the port 62. The arm 64 is biased so that the valve member is normally free of the port 62 when the liquid level in the reservoir is below the level of the valve 63 and thus under these conditions the port 62 is open to permitairto pass therethrough. As the level of the liquid rises in the reservoir 13, the buoyant nature of the valve 63 will cause the leg 64 to resiliently deflect towards a more upright position whereby the conical end portion 63a of the valve will move to close the port 62. It will be appreciated that the valve 63 will close before the interior 29 of the reservoir is completely filled with liquid and thus there will be a layer of air trapped in the reservoir, the function of which will be referred to later.

The dump valve assembly 40 is provided so that the fluid in the reservoir 29 may be discharged, after the completion of a cycle of operation of the device, to place the device in the condition ready to perform a further cycle. The dump valve port 41 communicates with the valve chamber 42 in which the dump valve 43 is located. The valve chamber 42 is separated from the pressure chamber 44 by the diaphragm 45 and upon the application of fluid pressure to the chamber 44, the diaphragm 45 deflects to raise the valve 43 against the action of the spring 46 to close the dump port 41. The dump passage 47 communicates the chamber 42 with the exterior of the reservoir 13 so that when the valve 43 is open, the fluid in the reservoir may discharge therethrough.The duct 50 formed in the wall of the reservoir 13 communicates the chamber 44 with the cavity 35 which in turn communicates with the filter chamber 25 and passage 15.

It will be understood that when the pressure in the passage 15 and hence in the chamber 44 is above atmospheric pressure, the diaphragm 45 will be deflected so that the dump port 41 is closed by the dump valve 43. Also upon the pressure in the passage 15 falling to atmospheric pressure, equal pressures will then exist in the dump valve chamber 42 and the pressure chamber 44, and hence the dump valve 43 will be permitted to open and the liquid in the reservoir 13 will discharge through the dump port 14 and the dump discharge passage 46.

The dump valve 42 thus operates automatically to place the control valve in condition for a further cycle once the inlet port 11 is disconnected from the source of liquid under pressure or the pressure of the liquid in the passage 15 is otherwise reduced to atmospheric.

The shut-off valve 17 is carried by the spindle 70 supported in the body 10 co-axially with the outlet port 12 and valve seats 18 and 19. The large dish-shaped head 71 provided at the lower end of the spindle 70 contacts the central area of the diaphragm 14 and also provides a seating for the lower end of the coil spring 72, seated at the upper end against the wall of the filter chamber 25. The seal assembly 73 is provided between the spindle 70 and the body 10 so that liquid cannot pass from the chamber 20 into the area above the diaphragm 14.

It will be understood that while the pressure on either side of the diaphragm 14 is equal, the spring 72 will maintain the diaphragm in a downwardly deflected condition as shown in Figure 1. Conse quently the valve 17 will seat on the valve seat 19, thus allowing liquid to pass freely from the inlet port 11 through the passage 15 and chamber 16 and out the discharge passage 12.

A control device as shown in Figure 1, is in its normal free condition ready to commence a cycle of operation. Upon the inlet port 11 being connected to a source of liquid under pressure, and that liquid is permitted to flow into the control device, that liquid will pass as previously stated out through the discharge port 12 for use in equipment such as a sprinkler.

Whilst the liquid flow is established through the discharge port 12, liquid will also pass through the passage 26 into the filter chamber 25 and hence into the cavity 35. From the cavity 35 some liquid will flow into the dump valve pressure chamber 44 and operate on the diaphragm 45 to move the dump valve 43 into a position to close the dump valve port 41.

Liquid will also flow from the filter chamber 25 through the control passage 27 into the interior of the reservoir 13. The rate of flow of liquid into the reservoir 13 is controlled by the position of the tapered section of the control screw 28 which is preset by the operator. The setting of the control screw 28 is selected in accordance with the duration of time for which it is required for the liquid to be delivered through the discharge port 12.

When the level of liquid in the reservoir 13 rises sufficiently to cause the air bleed valve 63 to close the bleed port 62 as previously described, the further flow of liquid into the reservoir 13 through the control passage 27 will commence to produce a rise in pressure in the reservoir 13. When the force acting on the diaphragm 14 as a result of the pressure in the reservoir 13 is sufficient to overcome the effects of the spring 72 and the water pressure acting on the valve 17, the diaphragm 14 will deflect upwardly moving the spindle 70 upwardly and carrying with it the valve 17.Immediately the valve 17 leaves the valve seat 19, the pressure of the liquid in the chamber 16 will apply also to the underside of the valve 17, thereby reducing the force necessary to move the valve upwardly, and thus the diaphragm 14, the spindle 70 and the valve 17 will quickly move to a position to seat the valve 17 on the discharge valve seat 18. This action of the valve is also assisted by the presence of air in the reservoir 13 as this air can expand with the movement of the diaphragm and thus maintain a higher pressure on the diaphragm which would be possible in the event of the reservoir being completely filled with liquid.

Once the valve 17 has seated on the discharge seat 18, there will be no further discharge of liquid through the discharge port 12, but the liquid under pressure may now pass through the chamber 20 and passage 21 into the by-pass port 22. The by-pass port may be coupled by a conduit to another control valve identical to that shown in the drawings which in turn operates the control of liquid to a further sprinkler or the like and that further control device will operate in accordance with the cycle just described. It will be understood that any number of these control devices may be connected in series in this manner so that a plurality of sprinkler devices are operated in sequence for a regulated period.

If only one control device is used, then a plug is provided on the by-pass port 22 and so long as liquid under pressure is maintained in the passages 15 and 21 and chambers 16 and 20, the valve 17 will remain in a position to close the discharge port 12, this condition being maintained by the pressure acting on the diaphragm 14. Upon the pressure in the passage 15, and hence in the other connected passages and chambers, falling to about atmospher ic pressure, such as by disconnection of the course of liquid from the inlet port 11, the dump valve 43 will immediately open as previously described so that the liquid in the reservoir 13 is discharged through the passage 46.During the discharge of the water from the reservoir the air bleed valve 63 will move to open the port 62 and the diaphragm 14will be deflected downwardly by the spring 72 to return the valve member 17 to the by-pass seat 19. Thus the control device is returned to its original condition in readiness to commence a further cycle of operation.

The control device is shown in a horizontal disposition and as constructed it will also operate in a vertical disposition with the inlet port 11 directed upwardly. The buoyant nature of the bleed valve member will still function to close the bleed valve, and the dump valve will still be at the bottom of the reservoirto drain the reservoir when the control device is in the vertical disposition.

Figures 4 to 7 illustrate an alternative embodiment of the flow control device which has particular advantages for domestic use wherein the water supply pressure may vary substantially from one location to another.

In this embodiment the control device comprises a body 110 having an inlet port 111 and a delivery port 112. The body 110 is also provided with a by-pass port 122 which has the same function as the by-pass port 22 as described with reference to Figures 1 and 2 of the drawings. The cylindrical filter element 150 is supported in the outlet port 111 by the insert 151 which is a push-fit into the body 110. Downstream of the filter 150 there is provided a flow restrictor 152 in the form of a diaphragm. The diaphragm 152 is made of a flexible material such as rubber or plastic, and has a series of preferably radial slits extending from the centre of the diaphragm towards the periphery thereof.The sectors of the diaphragm 152 formed by the radial slits are deflected by the water flow from the inlet port 111 as indicated in dotted outline in Figure 5 so that the water may flow through the control device whilst at the same time establishing a back pressure within the filter element 150, the purpose of which will be referred to in greater detail later in this specification.

The valve element 117 is disposed between the valve seats 118 and 119 respectively and is normally held against the valve seat 119 by the spring 172.

The valve element 117 operates in precisely the same manner and for the same purpose as the valve 17 referred to in respect of Figure 2.

The control reservoir 113 is secured to the body 110 by the clamp nut 152. The control reservoir 113 being provided with a peripheral rib 113a which co-operates with an internal shoulder 1 52a on the nut 150.

The control reservoir 113 has an internal liner 154 made of a flexible material such as rubber or plastic with a peripheral flange 155 extending between the upper edge of the control reservoir 113 and the face of the body 110 so as to form a liquid seal therebetween.

Avariabie volume chamber 129 is thus formed by the liner 154 and the body 110, the variation in the volume thereof being achieved by applying pressure to the external surface of the liner 154 in a manner which will hereinafter be described. During the variations in the volume of the chamber 129 air may move into or out of the chamber via the air bleed passage 162 provided in the body 110.

The dump valve assembly 140 is located in a lower part of the control reservoir 113 below the normal freestate level of the liner 154. The dump valve 143 co-operates with the dump port 141 so that when the valve 143 closes the port 141 liquid will accumulate in the control reservoir 113 and when the dump valve 143 is in the open position as shown in Figure 5 of the drawings, liquid in the control chamber 113 may freely discharge from the reservoir.

The dump valve rod 140a connects the dump valve 143 with the diaphragm 145 operating in the chamber 144. The dump valve chamber 144 communicates via the passages 156 and 157 and the cavity 158 with the delivery side of the filter 150. Thus the water entering the inlet port 111 is filtered before entering the chamber 144 and thus over a period of time there cannot be an accumulation of solid matter in the chamber 144 which may interfere with the function of the diaphragm 145.

When the dump valve assembly 140 in the position as shown in Figure 5, the resilience of the diaphragm 145 arising from the corrugated crosssection thereof will hold the dump valve 143 in the open position so that atmospheric pressure exists in the control reservoir 113. Upon water under pressure entering the inlet port 111, the water in the chamber 144 will rise to the pressure of the incoming water to overcome the force acting on the rod 140a as a result of the resilience of the diaphragm 145 so as to move the dump valve 143 into a position to close the dump port 141. The dump valve will then remain in this closed position until pressure is relieved in the diaphragm chamber 144, as will be hereinafter described.

The metering device 118 is shown in detail in Figure 6 and controls the flow of water from the inlet port 111 to the interior of the control reservoir 113.

The metering chamber 161 communicates with the inlet port 111 through the passage 160 extending from the external surface of the filter 150. Thus only filtered water enters the metering chamber 161. The metering needle 162 extends through the metering port 163 which communicates the metering chamber 161 with the control reservoir 113. The needle 162 is suspended from the diaphragm 164 via the needle holder 165 and the spring 166 acts on the holder 165 to urge the needle 162 in a downward direction as viewed in Figure 6. The control screw 180 engages the other end of the spring 166 and thus by rotation of the screw 180 the degree of compression of the spring 166 may be varied.

It will be understood that the force exerted on the needle 165 by the spring 166 will be opposed by the force applied to the diaphragm 164 bathe pressure of the water in the metering chamber 161. Accordingly variations in the pressure of the water in the metering chamber 161 would normally result in a downward movement of the needle 162 in the port 163. Accordingly if the needle 162 was a conventional tapered needle, a drop in pressure in the metering chamber 161 would result in a reduction in the clearance between the needle and the metering port.

Thus, the drop in pressure in the metering chamber would have a compound result on the flow of water through the metering port; firstly there would be the drop in flow resulting directly from the drop in pressure and secondly, there would be a drop in flow resulting from the downward movement of the tapered needle into the port 163.

However, in a control device such as the present invention is applicable to, it is most desirable for the metering device such as a device 118 to be able to be set to give a particular flow through the metering port 163 and for that flow to then not be unduly varied by possible fluctuations of the pressure of the water supply to the inlet port 111. In order to achieve this desirable result, the needle 162 is not tapered but of a constant diameter over that portion of its length which co-operates with the port 163. Along this length of the needle there is provided a longitudinally extending groove 162a in the external surface thereof which is V-shaped in a diamteral plane of the needle and progressively decreases in depth from the diaphragm end of the groove to the terminal end of the groove.Thus in operation, water flows from the metering chamber 161 through this longitudinal groove 1 62a to the control reservoir 113. With this construction when there is a drop in pressure in the chamber 161,the needle 162 will be moved down under the action of the spring 166, however this will result in an increase in the cross-section of the flow passage through the port 163 which will compensate for the reduction in pressure and thus maintain a substantially constant flow through the metering port 163.

It will be appreciated that two or more longitudinal grooves may be provided in the needle of the same configuration as above described, or alternatively the effective portion of the needle may be tapered with the largest end of the taper at the lower end of the needle, and the smallest diameter towards the diaphragm end of the needle.

The water entering the chamber 113 through the metering port 163 will accumulate in the reservoir 113 externally of the liner 154, and thus with the dump valve 143 closed, the liner 154 will be progressively deflected upwardly in the control reservoir 113, and will ultimately contact the head 171 of the valve spindle 170. The pressure of the water in the control chamber 113 will then be applied to the head 171 and upon the resulting force being sufficient to overcome the action of the spring 174, the valve 117 will be moved upward to contact the valve seat 118 and thus closing the outlet port 112, whilst at the same time connecting the by-pass port 122 to the inlet port 111.

The operation of the control device described above with reference to Figures 4 to 7 of the drawings, is basically the same as the previously described with reference to Figures 1 to 3. Thus briefly, the operation is, upon connection of the inlet port 111 to a pressure source of water, the water flows through the passage 115 over the valve seat 118 to the outlet port 112, which is connected to a water sprinkler or other device. The water passing from the inlet port 111 to the discharge port 112 passes through the cylindrical filter element 150 and thus carries out a continual cleaning operation on this internal surface and thus maintains the filter in a fully operational condition. When the water supply is connected to the inlet port 111 water also passes through the filter element 150 into the passages 157 and 160 respectively.The water entering passage 157 passes through chamber 158 and passage 156 to the dump valve chamber 144. The pressure built up in the chamber 144 by the incoming water acts through the diaphragm 145 to move the dump valve 143 to close the dump port 141.

Under most normal operating conditions the back pressure developed at the inlet port 111 is adequate to achieve effective operation of the dump valve assembly 140, and to divert water to the control reservoir 113 via the filter element 140 and metering device 118. However under low flow rate conditions in the inlet port, and without the flow restriction 152 or other restrictor, the back pressure developed may be insufficient to obtain reliable operation of the dump valve assembly and control reservoir. The flow restrictor 152 is designed to ensure that even with low flow rates the back pressure in the inlet port will not be below a predetermined minimum. The predetermined minimum back pressure is selected with reference to the pressure required for reliable operation of the dump valve and metering device, and is preferably of the order of 4 PSI.

Also the water passing from the filter through passage 160 is metered by the needle 162 and port 163 into the control reservoir 113 externally of the flexible liner 154. The rate of flow of the water into the control reservoir 113 is adjustable by the control screw 180 which sets the compression in the spring 166 and consequently controls the axial movement of the needle 162 under the influence of the water pressure in the chamber 161 acting on the diaphragm 164. The detailed operation of the control mechanism has previously been described.

The metered quantity of water will continue to flow into the control reservoir 113 causing the flexible liner 154 to be progressively raised into a folded and pleated condition as indicated in dotted outline in Figure 5 until the liner contacts the head 171 of the valve stem 170. When the liner reaches the stage that it can be no longer folded or pleated the pressure in the control reservoir 113 will commence to rise until it overcomes the action of the spring 174 and the pressure acting on the valve member 177 so as to move the valve member to engage the seat 118, thus closing the outlet port 112 and at the same time, communicating the passage 115 with the by-pass port 122. It will be understood that once the dump valve 143 closes the dump port 141, there will be a quantity of air trapped in the control reservoir 113 which cannot escape as the level of water rises in the control reservoir, and thus a cushion of air will be present in the control reservoir during the period of actuation of the valve 117 to function in the manner previously described with reference to the embodiment of the invention illustrated in Figures 1 to3.

Again, as previously described, once the valve 117 has closed the outlet port 112, the control device will remain in a static condition until the water pressure in the inlet port 111 and passage 115 falls to approximately atmospheric pressure. Upon this fall in pressure, a similarfall in pressure will occur in the chamber 144 and hence the resilience of the dump valve diaphragm 145 will move the dump valve 143 to the open position so that the water in the control reservoir 113 will discharge through the port 141.

Upon the discharge of the water from the control reservoir, the spring 174 will return the valve 117 to its initial pqsition closing the communication to the by-pass port 122 and opening the passage to the outlet port 112.

It is to be understood that some or all of the variations incorporated in the embodiment illustrated in Figures 4to 7 of the drawings may be incorporated into the construction shown in Figures 1 to 3 of the drawings and vice versa, that is to say, the use of the flexible liner 154 may be incorporated into the construction illustrated in Figures 1 to 3 as a re-placement for the diaphragm and the air bleed device. Equally the diaphragm and air bleed device of the embodiment shown in Figures 1 to 3 could be incorporated into the embodiment described with reference to Figures 4 to 5. Likewise, the dump valve construction, the water metering device or the filter described with reference to the construction shown in Figures 4to 7 of the drawings could be incorporated singularly or in any combination into the construction shown in Figures 1 to 3 of the drawings.

The maximum cycle time of the control device is related to the capacity of the reservoir, however provision may be made to connect one or more auxiliary reservoirs to increase this capacity. Each auxiliary reservoir would preferably have an air bleed valve, however provided the auxiliary reservoir is not lower than the reservoir of the control device, additional dump valves are not required.

Some of the principal advantages of the flow control device described above are 1. No manual resetting of the device is necessary between successive operations.

2. A number of the devices can be coupled in series to automatically operate in sequence.

3. The device may be operated in either a vertical or horizontal position.

4. The device can operate effectively on an unfiitered water supply.

5. The main valve member is held closed by the supply water pressure once the outlet port is initially closed by the operation of the water in the reservoir.

Claims (26)

1. Afluid flow control device comprising a body having inlet and outlet ports and a main conduit providing a passage for fluid from the inlet to the outlet port, main valve means operable to interrupt fluid flow communication between said inlet and outlet ports, a fluid reservoir, adjustable bleed means communicating with the main conduit on the inlet side of the main valve means with the reservoir to divert portion of the fluid entering the main conduit into the reservoir, and means responsive to the pressure in said reservoir to actuate said main valve to interrupt communication between said inlet and outlet ports upon a predetermined pressure difference existing between the main conduit and the reservoir.

2. Afluid flow control device as claimed in claim 1 including a reservoir air bleed assembly comprising a port in the reservoir communicating the interior thereof with atmosphere, and a bleed valve member operable to close said port to prevent the escape of air from the reservoir upon fluid in the reservoir reaching a predetermined level.

3. A fluid flow control device as claimed in claim 2 wherein said valve member is biased towards an open position.

4. A fluid flow control device as claimed in claim 2 wherein said predetermined level of fluid in the reservoir is below the level at which the reservoir is filled with fluid.

5. Afluid flow control device as claimed in claim 1 including a dump valve assembly to control discharge of fluid from said reservoir, said assembly being adapted to close to prevent said discharge of fluid upon the pressure in the main conduit exceeding a predetermined value.

6. A fluid flow control device as claimed in claim 5 wherein the dump valve assembly comprises a dump valve member biased towards an open position permitting the discharge of fluid from the reservoir, and means operable by the pressure of the fluid in the main conduit to move said dump valve member to a closed position to prevent said discharge of fluid upon the pressure in the conduit exceeding said predetermined value.

7. Afluid flow control device as claimed in claim 2 including a dump valve assembly to control discharge of fluid from said reservoir, said assembly being adapted to close to prevent said discharge of fluid upon the pressure in the main conduit exceeding a predetermined value.

8. Afluid flow control device as claimed in claim 1 wherein the means to actuate the main valve member include a diaphragm forming one wall of the reservoir, said diaphragm being operably connected to the main valve member to actuate said main valve member in response to deflection of the diaphragm upon establishment of said pressure difference.

9. A fluid flow control device as claimed in claim 5 wherein the means to actuate the main valve member include a diaphragm forming one wall of the reservoir, said diaphragm being operably connected to the main valve member to actuate said main valve member in response to deflection of the diaphragm upon establishment of said pressure difference.

10. A fluid flow control device as claimedin claim 1 wherein the body includes a secondary conduit communicating with the said main conduit through a by-pass port, said main valve member being movable to selectively close the outlet port or the by-pass port.

11. A fluid flow control device as claimed in claim 10 wherein the main valve member is biased to move in the direction to close the by-pass port.

12. A fluid flow control device as claimed in claim 10 wherein the outlet port and by-pass port are disposed in alignment in opposite walls of a chamber forming part of the main conduit, said main valve member being located in said chamber and supported to move thereacross to selectively close said outlet or by-pass port.

13. A fluid flow control device as claimed in claim 1 including filter means interposed between the conduit and the adjustable bleed means to filter the fluid passing to the bleed means.

14. A fluid flow control device as claimed in claim 13 wherein the filter means comprise a chamber divided into upstream and downstream sections by a filter element, the upstream section communicating with the main conduit to receive fluid therefrom, and the downstream section communicating with the adjustable bleed means and the dump valve assembly to provide filtered fluid to each.

15. A fluid flow control device as claimed in claim 1 wherein a filter member is disposed in the main conduit so that fluid flowing in the main conduit will move across one surface of the filter member, and so that fluid enters the filter member through said surface to flow from the inlet port to the bleed means.

16. A fluid flow control device as claimed in claim 15 wherein the filter member is hollow and said one surface is the internal or external surface thereof.

17. Afluid flow control device as claimed in claim 15 wherein the filter member is of a tubular form with the internal surface forming said one surface.

18. Afluid flow control device as claimed in claim 6 wherein a filter member is disposed in the main conduit so that fluid flowing in the main conduit will move across one surface of the filter member, and so that fluid enters the filter member through said surface to flow from the inlet port to the bleed means and to a conduit communicating with the dump valve assembly.

19. Afluid flow control device as claimed in claim 1 wherein the adjustable bleed means comprises a variable size port, selectively adjustable means to set the size of said port for a predetermined flow rate through the port at a predetermined entry pressure, and automatic means to vary said selected size to compensate for variation in pressure from said predetermined entry pressure.

20. Afluid flow control device as claimed in claim 19 wherein said variable size port comprises a port and a needle valve extending therethrough adapted so that the effective size of the port opening is determined by the axial position of the port relative to the needle, and the automatic means are responsive to the entry pressure to increase the effective size of the port on a decrease in entry pressure and vice versa.

21. A fluid flow control device as claimed in claim 20 wherein the automatic means comprise a movable member, subjected to said entry pressure to induce movement thereof in one direction, a spring acting on said member to induce movement in the opposite direction, said movable member being connected to the needle so that movement in said one direction will move the needle in a direction to reduce the effective size of the port.

22. A fluid flow control device as claimed in claim 22 wherein the movable member is a diaphragm.

23. A fluid flow control device as claimed in claim 22 wherein the needle has an operative portion which moves in the port during movement to compensate for entry pressure variations, said operative portion having a cross-sectional area that progressively increases in the direction of said opposite movement.

24. Afluid flow control device as claimed in claim 1 wherein the body has an internal chamber and the means to actuate the main valve means includes a flexible liner disposed within the chamber and sealed about the perimeter to the body, said liner dividing the chamber into a first section on one side of the liner in communication with atmosphere externally of the body and a second section on the other side of the liner forming the reservoir, said means to actuate the main valve means also including an operator member extending into said first section of the chamber and operably connected to the main valve means, whereby fluid entering the reservoir displaces the flexible liner to engage said member and actuate the main valve means.

25. A fluid flow control device as claimed in claim 24 wherein the said main valve means includes a valve member supported in the body for movement between open and closed relationship with respect to said outlet port, said valve member being connected to said operator member, and spring means arranged to urge said valve member to the open relationship with the outlet port.

26. A fluid flow control device substantially as herein described with reference to Figures 1 to 3 or 4 to 7 of the accompanying drawings.