AU685963B2 - Improvements in inlet flow valves - Google Patents

Description

I S F Ref: 254D

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATIONl FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: LI- Pw .Vr~io- 1--1 Li PD 6ov Actual Inventor(s): Bidar Pty Ltd .1 rEV ii HelcnStret -o -Merewethcr New South NWales 2Z91 2:?oo Avs7i-u-A- Paul Francis Tisdell and Gary Keith Thorpe Address for Service: Invention Title: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Males, 2000, Australia Improv-3ments in Inlet Flow Valves best method of performing it known to me/us:- 1. or 5845 Improvements in Inlet Flow Valves Field of the Invention This invention relates to improvements in inlet flow valves and component parts therefor. Embodiments of the flow valve find application in domestic toilet cisterns and stock water troughs, for example.

Related Prior Art An indication of the prior art, can be obtained from US Patents No. 3,980,457, 4,444,217, 4,967,789, 5,014,735, 4,379,434, 3,854,390 and 5,176,167, and from published Australian Application No. 81732/91.

Summary of the Invention Therefore, the invention discloses a flow control valve for controlling the flow of a liquid to a reservoir, said valve comprising: a valve body having a first chamber therein; an inlet duct in fluid communication with a supply of the liquid, the inlet duct being in fluid communication with the first chamber, the first chamber being partitioned by a seat diaphragm to close off the inlet duct from an outlet of the first chamber, the 20 outlet in turn in fluid communication with an outlet duct and so to the reservoir, dithe seat diaphragm having an orifice therethrough; t a magnetically attractive elongate plunger body resiliently mounted to be urged :to close the orifice, the plunger body having an end adapted to close the orifice; and displaceable actuating means carrying permanent magnet means adapted to interact with the plunger body to move the plunger body to open or close the orifice respectively with motion of the actuating means, thereby respectively tending to close :or open the flow control valve, wherein the plunger body includes an internal cavity and a magnetically interactive member located within the internal cavity, the member adapted to be slidable along the longitudinal axis of the body between two end travel limits under external magnetic influence of the permanent magnet means so as to impart kinetic energy to the body, the member having a mass that is significant in relation to the mass of the body so as to maximise the impulse of the kinetic energy when the member reaches one of the two end travel limits.

The invention further discloses a flow valve for controlling the level of water in a reservoir having a 'time-on' delay function.

INA\LIBkI00248:VXF -2- The invention yet further discloses an automatically controlled irrigation flow valve having both 'time-on' and 'time-off' delay functions, Embodiments of the invention provide one or more of the following advantages over conventional flow valves.

When the inlet flow valve is open, the supply pressure and inlet/outlet size alone govern the flow rate through Lhe valve. The valve opens for full flow with a smooth action and can deliver the maximum flow rate without need for throttling until the valve closes by the same smooth action.

The size of the flow valve inlet and outlet, which typically must be matched to existing supply pipework and cistern outlet pipe respectively, places no restriction on the achievable flow rate, The valves can accommodate very high supply pressures. In some embodiments this is due to a rigid disk backing the diaphragms.

S 15 Brief Description of the Drawings A number of preferred embodiments of the i-vention now will be described with reference to the accompanying drawings, in which: Fig. 1 shows a cross-sectional view of a self-regulating inlet flow valve for a flushing tank, with the valve in the closed position; Fig. 2 shows a similar cross-sectional view of the valve of Fig. 1, but in the opened position; Fig. 3 shows a cross-sectional view of a self-regulating inlet flow valve for a stock trough valve, with the valve in the closed position; Fig. 4 shows a similar cross-sectional view of the valve of Fig. 3, but in the opened position; Fig. 5 shows a cross-sectional view of another self-regulating inlet flow valve for a toilet cistern, with the valve in the closed position; Fig. 6a shows a similar cross-sectional view of the valve of Fig. 5, but in the opened position; Fig. 6b is a cross-sectional view along line A-A of Fig. 6a; Fig. 7 is a cross-sectional view of another self-regulating inlet flow valve; Figs. 8a-8e show detail of a plunger mechanism suitable for use in a number of the embodiments of the flow valve; Fig. 9 is a cross-sectional view of a further inlet flow valve having a sensing fiunction; Fig. 10a is a cross-sectional view of an inlet flow valve suitable for irrigational pu-poses, and with the valve in the opened position; Fig. 10b is a cross-sectional view of the valve of Fig. 10a, but in the closed position; and IN\LIBkIOO248:BFD -3- Fig. 11 is a cross-sectional view of a yet further inlet flow valve arrangement.

Detailed Description of Preferred Embodiments A number of embodiments of self-regulating inlet flow valves will be described. All of the valves embody the same inventive concept; minor differences between the embodiments often are dictated simply by the particular applicational requirements. It is to be understood that the valves are suited to use with any liquid, and not simply water.

The first embodiment is a valve suitable for a domestic flushing tank, which typically receives mains pressure water supply (typically of about 300 kPa) at a flow rate necessary to fill a small volume (say 15 litres) in approximately 30 seconds, thus producing a relatively fast moving reservoir water level.

The second embodiment relates to a stock trough valve which, in contrast with the first embodiment, requires a low inlet pressure (in the range of 10-100 kPa) at a flow rate sufficient to fill a relatively high volume (say 600 litres) over a longer period of time, thus producing a very slow moving water level.

The flow valve 10 shown in Figs. 1 and 2 is located within a flushing tank and held in place by suitable fixing means (not shown). The level of water within the tank 40 is controlled by the valve 10 to vary in a range between the points and "z' as shown. The flow valve 10 can be cylindrical or rectangular in external configuration as is convenient for the shape of the tank The valve 10 comprises three housings: an upper housing 11, a mid-housing 12 and a lower housing 13, The valve 10 has two diaphragms, the first being a sensing diaphragm 14 and the other being a seat diaphragm 15. The sensing diaphragm 14 is secured between the upper housing 11 and the mid-housing 12, the assembly thereof being secured by bolts or pins 16. In a similar way, the seat diaphragm 15 is secured between the midhousing 12 and lower housing 13 by means of bolts or pins 17. The arrangement of the three housings 11,12,13 and the two diaphragms 14,15 forms three distinct chambers.

These are an upper chamber 18, a mid-chamber 19 and a lower chamber The inlet tube 21 and the outlet tube 22 of the valve 10 respectively are formed as a part of the lower housing 13, with the inlet tube 21 having a connection to the mains water supply (shown in phantom). The upstream end of the outlet tube 22 has a machined face 30 to provide a positively sealing seat for the seat diaphragm A spring-loaded plunger is located within the lower chamber 20. The plunger comprises a spring 23 connected from the mid-housing 12 at the top of the lower chamber 20 to a plunger body 24 which, in turn, acts against the seat diaphragm The plunger body 24 has a neoprene tip 25, and also carries a cylindrical ceramic ferrite permanent magnet 26.

IN:\LIBkIOO248:BFD The sensing diaphragm 14 carries a rigid disc-like member 28, which houses a ceramic ferrite magnetic assembly, in this case in the form of a ring-shaped permanent magnet 27 positioned so that when the plunger body 24 moves under the influence of the seat diaphragm 15, the cylindrical magnet 26 interacts with the magnetic field of the ring magnet 27.

An equalising tube 29 vents the upper chamber 18 to above the high water level of the tank 40. A vent plug 35, connecting the tank 40 with the mid-chamber 19, also is provided.

Operation of the flow valve 10 now will be described.

Fig. 1 shows the valve in the closed position, and with the water in the tank at the high level Water from the mains inlet pipe enters the inlet tube 21 and passes through an orifice 31 in the seat diaphragm 15 to fully occupy the lower chamber The spring 23 forces the plunger body 24 downwardly such that the tip 25 seals the small central orifice 32. Inlet water therefore is present on both sides of the seat 15 diaphragm 15, and due to a lower pressure existing in the outlet tube 22, the seat diaphragm 15 is forced to seat against the face 30 of the outlet tube 22. This prevents the inlet water from entering the outlet 22. The seat diaphragm 15 is of sufficient rigidity to resist bending into the outlet tube 22 under the influence of the inlet water pressure, which otherwise would create a leak.

Water from the tank 40 fully occupies the sensing tube 33 to pass to the midchamber 19. In this regard, the mid-chamber 19 initially must be primed to expel all air, and this is achieved by means of the vent plug 35. The water from the sensing tube 33 applies a net upwardly directed pressure acting against the sensing diaphragm 14, which causes the diaphragm to rise upwards to its upper limit of travel. That upper limit of travel is dictated by interaction of the stops 34 butting-up against the underside surface of the upper housing 11, and is related to the tank high water level as presently will be explained. The air displaced by the sensing diaphragm 14 is expelled by the equalising tube 29.

In further operation of the valve 10, and particularly as shown in Fig. 2, a flushing valve (not shown) causes the water stored within the tank 40 to discharge, in which case the water level within the tank starts dropping. When the tank level falls to level the net upwardly directed force acting on the sensing diaphragm 14 then is negated, since below this level, water within the mid-chamber 19 is at a greater head of pressure than the water within the tank, hence there is outflow of water via the sensing tube 33.

As the water level further reduces, a negative downwardly directed force is applied to the sensing diaphragm 14 which draws the ring magnet 27 downward towards the cylindrical magnet 26. The ring magnet 27 is arranged to have a south pole on its lower side and a north pole on its upper side. The cylindrical magnet 26 has 1N:\LIBk100248:BFD its poles configured in an opposite sense: a south pole on its upper side and a north pole on its underside. This means that as the magnets approach there initilly is a tendency for them to repel each other. This magnetic repulsion can be overcome by the mass of the diaphragm/disc member combination falling under the influence of gravity and/or the influence of negative pressure due to water outflowing from the mid-chamber 19.

When the water level drops to level being at a point below the openings to the sensing tube 33, the sensing diaphragm 14 has lowered onto the stops 36. An attractive force now exists between the respective north and south poles of the ring magnet 27 and the cylindrical magnet 26, so the plunger body 24 instantly moves upwardly and the cylindrical magnet 26 is captured in the stable position (illustrated in Fig. 2) in the middle of the ring magnet 27. The plunger body 24 is effectively balanced, in that repulsive forces resist motion of the plunger body 24 either upwardly or downwardly from the equilibrium position.

The sensing tube 33 remains full at all times will not syphon) since air cannot enter the mid-chamber 19 during the tank discharge due to the chamber being "primed, as previously discussed. This prevents the escape of all the water from the midchamber 19. The water level within the mid-chamber 19 therefore varies only by the volumetric difference between the travel limit positions dictated by the two sets of stops S"34,36.

With the plunger body 24 raised, the central orifice 32 is opened, and allows water to pass from the lower chamber 20 to the outlet tube 22. This causes the seat diaphragm 15 to be unseated from the face 30 due to the inlet water pressure acting on the diaphragm, and so the full inlet water flow can pass directly to the outlet tube 22 to commence refilling of the tank 40. The plunger body 24 and the central orifice 32 act as a bleed mechanism.

As the water level rises, the pressure within the mid-chamber 19 increases tending to drive the sensing diaphragm 14 upward. As the sensing diaphragm 14 rises up, the ring magnet 27 draws the cylindrical magnet 26 with it, so that the plunger body 24 acts to compress the spring 23. The configuration is arranged so that when the water level reaches position the sensing diaphragm 14 has risen upwardly to a point where the plunger body 24 engages the end stops 37, and so the retaining magnetic force can be broken with further travel of the sensing diaphragm 14 under the influence of the increase in water pressure in the mid-chamber 19, resulting in the cylindrical magnet 26 being repelled to return to the position shown in Fig. 1 under the influence of the energy stored in the fully compressed spring 23, together with the now repulsive magnetic interaction of the magnets 26,27.

Clearly the spring 23 must be sized so as not to be fiilly compressed before the plunger body 24 engages the end stops 37.

IN:\LIBk10O248:BFD Once the plunger body 24 has returned to the position where it closes-off the central orifice 32, the pressure within the lower chamber 20 begins to rise, continuing until the seat diaphragm 15 again seats against the machined face 30, thereby blockingoff the flow of inlet water to the outlet tube 22. The time between the plunger body 24 being repelled and closing-off of the outlet tube 22 will be very short.

The flow valve 10 thus has completed a full cycle, and is ready for the next use.

Another arrangement for the inlet valve 10 is configured such that when the plunger body 24 is captured by interaction of the cylindrical magnet 26 and the ring magnet 27 it instantly engages the ends stops 37. The plunger body 24 therefore is either in the equilibrium position, or restrained in a position where it experiences a positively attractive influence. In operation, the diaphragm 14 rises upwardly, as described previously, however the plunger body is now constrained from moving. The S 15 magnetic attraction lessens with further upward movement of the diaphragm 14, and at a point then becomes repelling and the plunger body 24 restores to the position shown in Fig. 1. It is often the case, therefore, that the restoring influence of the spring 23 is not required.

The particular 'instantaneous' action of the plunger due to the interaction of the Smagnetic assemblies allows the upper and lower water levels, and to be set accurately, and to be consistently repeatable.

The second embodiment relates to a stock trough flow valve. This embodiment conceptionally is the same as the flow valve described above, and like component parts have been identified by the same reference numerals.

In the embodiment, the stock trough valve 50 is separated from the stock trough 90, in distinction with the arrangement for the first embodiment.

The valve 50 shown in Figs. 3 and 4 includes an outlet diaphragm 51 which has been incorporated in the lower housing 13 to seat or seal-off the outlet tube 22.

The equalising tube 29 of the first embodiment has been replaced by a cap arrangement 52, essentially to stop airborne particles from blocking-off the venting action.

Similarly, the sensing tube 33 has been replaced by a tube 53 formed integrally between the upper, mid and lower housings 11,12,13. A priming vent screw 58 takes the place of the vent plug 35. It will be appreciated by those skilled in the art that the tube 53 can be of any length so the valve 50 can be remote from the trough and/or operate a number of troughs each set to the same height of water.

As previously discussed, the stock trough flow valve 50 can accommodate high supply heads as well as supply pressures down to less than lOkPa.

Fig. 3 shows the stock trough valve 50 in a closed position corresponding to full water level in the trough 90, represented by the level At this level, the pressure applied to the sensing diaphragm 14 in the mid-chamber 19 by means of the [N:\LIak1lO248:BFD -7tube 53 causes the sensing diaphragm 14 to rise to its upper limit of travel. The inlet water passes through an orifice 54 in the outlet diaphragm 51, and through a further duct 55 to enter and fill the lower chamber 20, passing through the orifice 31 in the seat diaphragm 15. The pressure of water acting on the outlet diaphragm 51 is sufficient to close off the 'waste' tube 57. The diaphragm 51 has sufficient rigidity to avoid collapse under the inlet pressure and so maintains a good seal to close-off the outlet tube 22.

As the water levl drops to level through evaporation, or by being consumed by stock, the pressure acting on the sensing diaphragm 14 reduces, causing the disc 28 carrying a ferrite permanent ring magnet 56 gradually to lower as the water pressure in the mid-chamber 19 reduces. When the water level in the trough 90 reaches the level being the low water level (as can be seen from Fig. the sensing diaphragm 14 is at its lowest level, in which case, as with the first embodiment, the cylindrical magnet 26 is captured causing opening of the central orifice 32. This is e• followed by a cascading effect, whereby water in the lower chamber 20 passes to the waste tube 57 to equalise with the pressure in the outlet 22. Following on, the outlet diaphragm 51 is unseated from the entrance to the outlet tube 22 due to the higher inlet pressure acting on the outlet diaphragm 51, and so opens the outlet tube to full flow from the inlet tube 21.

The stock trough valve 50 operates generally in the same way as described for the first embodiment as the water level rises, in that the spring 23 becomes compressed until the plunger body 24 engages the end stops, after which time further upward motion of the pair of magnets 56 will release the plunger body 24 and cause the staged shutting-off of the seat diaphragm 15 and the outlet diaphragm 51 when the water level has returned to the level For both the flushing tank flow valve 10 and stock trough flow valve 50, the water supply may contain contaminants such as fine metal particles, hence it is desirable to incorporate forms of filtering. Filters such as gauze or a fine metal mesh can be installed in the inlet pipe 21 or the duct 55 to block the passage of bodies which might block the orifices 31,32 and cause the valve to fail. Indeed, the filters may be incorporated into the seat diaphragm 15, and specifically spanning either one or both of the seat diaphragm orifice 31 and the central orifice 32.

The invention can be configured to accommodate a large number of applications by varying the size, strength and material of various components of the valve. Where there are higti inlet pressures, a strong field strength may be preferred for the interacting magnets, together with small orifices in the seat diaphragm 15. For low inlet pressures a relatively weak field strength is required for the interacting magnets.

[N:\LIBkIO024B:BFO High flow rate volumes require large inlets and outlets and large diaphragnl.seat areas. Furthermore, fast moving reservoir fluid levels require a large sensing tube volume to reduce the time lag caused by fluid filling the mid-chamber 19.

That same chamber should have a small residual volume and the equalising tube should be larger.

The fluid level or height of a reservoir can easily be adjusted by means of the mass of the disc member, by the size and material of the sensing diaphragm or the feld strength of magnetic interaction between the magnets. For example, the sensing diaphragm 14 can be replaced by a suitable flotation mechanism, such as a bubble float.

Figs. 5, 6a and 6b show another embodiment of a self-regulating inlet flow valve for a toilet cistern which, while operating on the same principle as the embodiments already described, replaces the sensing diaphragm 14 with a flotation arrangement.

The flow valve 60 is suited to be mounted within a cistern 40 at a position above the water level corresponding to a full flush volume of water. The cistern valve 60 has connection to a supply of water by means of an upstanding inlet tube 21.

The tube 21 is affixed to the base of the cistern by an appropriate threaded locking collar 61. The inlet tube also connects with the lower housing 13 by means of threaded S"engagement 69. The lower housing 13, in turn, fastens to the mid-housing 12 by means of locating bolts or pins 17.

The basic structure of the cistern valve 60 is completed by a float assembly formed of the float 62 concentrically mounted around (or at least surrounding) the inlet pipe 21, with the upper end thereof attached to a covering housing 63 that carries a permanent ring magnet 27. The float assembly is free to rise and fall with the water level in the cistern 40, and is held in place by the sliding interaction of the housing 63 with the upper sides of the mid-housing 12 in the vicinity of the ring magnet 27.

Fig. 5 shows the instance where the cistern 40 is fully filled to level In.

this situation, supply water has filled the inlet tube 21 passing the mesh filter 64 and occupying six finger-like inlet ducts 65, and so to fill the lower chamber 70. The water passes through the orifices 31 in the same manner as for the previously described embodiments. The plunger body 24 blocks-off the central orifice 32, thus increasing the water pressure in the portion of the chamber 20 above the diaphragm 15 as inlet water enters through the communicating orifice 31 and is prevented from leaving by the central orifice 32. The pressure increase applies a downward force on the diaphragm 15 thus seating it against the face 30 of the outlet chamber 66.

The relative arrangements of the interleaved inlet ducts 65 and outlet ducts 67 are best seen in Fig. 6b.

When the water within the cistern is discharged due to flushing taking place (by flushing means that are not shown), the water level drop:. As it drops, the float 62 IN\LIBk3OO24::BFD -9sinks downwardly with the reduction in the buoyancy force, thereby carrying the ring magnet 27 towards the plunger body 24. The mass of the housing 63 must overcome the oppositely directed buoyancy force of the float 62 and the initial magnetic repulsion between the magnets 26,27.

When the water level has dropped to the water level the ring magnet 27 has lowered onto the end limit of travel stops 68 and is in a position where the cylindrical magnet 26 carried on the plunger body 24 and the ring magnet 27 attract.

The magnetic attraction is sufficient to overcome the gravitational force acting on the plunger body 24 and the sealing force of inlet fluid pressure holding the plunger body 24 to the orifice 32, hence the plunger body 24 is captured, thereby causing a small upward motion, and thus opening the central orifice 32. This allows the passage of water from the chamber 20 to the outlet chamber 66, and so via the outlet duct 67 to the cistern. As the flow to the outlet increases, the seat diaphragm 15 moves upwardly, thereby opening a direct passage between the inlet duct 65 and the outlet chamber 66, o. enabling full flow to be achieved in order that the cistern 40 is filled without undue time delay. The plunger body 24 is carried upwardly and butts against the end stops 37, as shown in Fig. 6a.

As the water level in the cistern rises further, the buoyancy force acting on the float 62 seeks to carry the plunger body 24 further upwardly. As the water level rises, the buoyancy force overcomes the resistive magnetic force, and the float 62 rises up to a point corresponding with water level in which case the cylindrical magnet 26 is removed frora the influence of the ring magnet 27, and is free to move smoothly downwardly under the influence of gravity which may be assisted by the spring 23 and the now magnetically repulsive force to again close-off the central orifice 32.

As water pressure builds up within the lower chamber 20, the seat diaphragm is caused to close-off the inlet ducts 65 from the outlet chamber 66, thereby returning to the situation as shown in Fig. 5. For a valve designed for a domestic cistern, the travel of the float 62 between the open and closed position may be as little as 4mm.

In setting the high and low water levels in the cistern 40, there are a number of design variables which can be manipulated. Particularly, the float length, thickness and material conveniently can be varied.

The arrangement whereby the float 62 extends over substantially the whole length of the inlet tube 21 within the cistern has the particular advantage of being a noise reduction mechanism. Water discharging from the outlet ducts 67 is directed downwardly, as has been described. There is thus a noise source due to the discharging water obliquely impacting with the inside surface of the housing 63, and due to impact of water into the cistern. These noise sources do not have a direct air path t. free air outside of the cistern, rather are attenuated by a tortuous path around IN:\LIBk]OO248 BFD the bottom ot the float 62 which will be closed off by the water in the cistern as the water level rises, and by the. transmission loss/absorptivity of both the float 62 and water.

The embodiment just described also provides the same advantages and operational performance as for the other embodiments.

Fig. 7 shows a further embodiment of an inlet flow valve 75 suitable for installation in a cistern. In this regard, the further embodiment is somewhat similar to the valve shown in Figs. 5, 6a and 6b, and like elements are indicated by the same reference numerals. The flow valve 75 is shown in the opened position.

ie A first characterising difference of the valve shown in Fig. 7 over that of Figs.

6a and 6b is that the inlet valve 21 no longer terminates in finger-like inlet ducts nor the similarly shaped outlet ducts 67. Rather, the inlet tube 21 extends into a single c_ mnnel 80, thus providing access to seat diaphragm 15. The passage 80 typically extends for about one-third of the circumference of the valve. The outlet chamber 66 extends into an outlet passage 82, itself also extending partly circumferentially of the valve. The mouth of the outlet passage 82 provides for discharge of water into the cistern 40. The inlet passage 80 and outlet passage 82, therefore, are isolated from one another, and the larger inlet/outlet surface area has been determined to be beneficial in reducing noise in the operation of the valve over the finger-like arrangement of the previous embodiment.

Another feature of the valve 75 is an arrangement whereby the float 62 is separately and adjustably mounted from an extended version of the housing 63. This configuration further cooperates with an adjustable spring arrangement. The float 62 is S. height-adjustable between indexing positions 84 on the downwardly extended legs (skirt) of the housing 63. The top of the housing also is extended to a threaded *extension 86, onto which screws a base plate 88 for a tensioning spring 90. The other end of the spring is captured in a race 92 formed on an upper surface of the housing 63.

In operation, the compressive force of the spring 90 acts against the float 62.

By adjustment of the base plate 88, and similar adjustment of the location of the float 62 according to one of the indexing positions, precise control can be had over the high water level This means that the il-,ve 75 is suited to installation in many varying configurations of cistern or stock trough valves, thereby having a universality of application by virtue of the adjustments that can be made, and hence having improved utility over flow valves designed specifically for particular cistern configurations.

Another modification common to all of the flow valves previously described relates to the instance where the spring 23 is not required. The mass of the plunger body 24 acting under gravity and the magnetic repulsive force can be sufficient to restore the plunger body without requiring the assistance of the stored energy in the previously utilised compression spring 23. It is preferable, but not essential, that the IN:\LIBkIOO248:BFD st -11plunger body 26 be located in a vertical plane, or at least at an angle of not more than from the vertical, but otherwise only need be guided (laterally restrained) by the enveloping sides within the housing 63.

This configuration also is advantageous in respect of reducing the incidence of water hammer. Water hammer is the phenomenon where mechanical shock waves travel along water carrying pipes, often due to last-acting valves. The modification is rather in the nature of a 'soft' opening and closing valve. The improved performance is by virtue of the diaphragm 15 always following in close contact with the plunger 24 as the valve opens or closes. As the plunger seals the orifice 32, the diaphragm will try to close the valve due to an increase in water pressure in the region of the chamber above the diaphragm. If the plunger is pulled away from the diaphragm, the diaphragm will follow the plunger upwardly due the pressure of inlet water acting on the underside surface of the diaphragm and because there is a lower pressure above the diaphragm than below due to the orifice 32 being larger in area than the communication port 31.

'Soft' opening and closing is due to the speed at which the plunger 24 can move. The plunger is immersed in water and to rise it must displace the water directly above. That displaced water flows cown the sides of the plunger body. Therefore, the rate at which it falls is governed by the clearance of the plunger from side walls of the S•housing in which it is mounted, the mass of the plunger, the viscosity of the water and 20 force of the spring 23 (if fitted).

f." Fig. 8 shows an alternative configuration replacing the spring, "laded plunger shown in the previous embodiments. The plunger 100 directly substitutes for the plunger-like body as previously shown, for example, in Fig. 1. The plunger 100 is received into, and moves within, the guide formnied in the mid-housing 12. The two sets of stops 36,37 also have been shown. The polarities of the magnets ;c Ain as previously described.

The plunger 100 comprises an open-ended cylindrical body 102, the blind end of which is provided with resilient end-travel buffer 104. A cylindrically shaped sliding magnet 106 is received within the body 102, and held in place by an end cap 108 that screws into the threaded open end of ,he body 102 to form an airtight seal.

The end cap 108 also is provided with a sealing plug 110 that is equivalent to the neoprene tip 25 described in Fig. 1. The end plug 108 further includes a second resilient end-travel buffer 112 at the inner end thereof. The two buffers 104,112 act to form end stops for the magnet 106 between its travelled positions.

Operation of a flow valve incorporating the plunger 100 differs from the plungers described previously. In those cases the force holding the plunger body against the central orifice 32 is the product of dithe water pressure in the valve and the area of the orifice 32. For the valve to open, the attractive force between the IN\LIBk10OO248:BFD u ra -12cylindrical magnet 26 and ring magnet 27 mnwt he greater than the plunger held against the orifice.

The interaction of the plunger 100 with the magnet 106 is si-ch as to travel the length of the guide to engage either one of the respective buffers 104,112 before causing the plunger body 102 to move either upwardly or downwardly. The cylindrical magnet 106 is free to move inside the plunger body (case) 102, and its mass is significant in relation to the mass of the case 102.

As the ring magnet 27 (not shown) approaches the cylindrical magnet 106, a magnetic attraction occurs sufficient to overcome the force of gravity or any other force restraining the magnet 106. As the ripg magnet 27 further moves towaids the cylindrical magnet 106 it is accelerated by an inverse-square increase in magnetiZ field strength. When the plunger body thus reaches the upper end of the case 102, it 1its significant momentum, which is converted into an impulse force further assisting in, 15 unseating the plunger body 102 from the central orifice 32. In this way, a valve can be opened at greater water pressures for a given magnetic attraction than if the cylindrical magnet were fixed to the case.

The plunger 100 equally can be fabricated as a one-piece structure, although it ~.is necessary that the components other than the magnet 106 exhibit no residual magnetib~n, or otherwise are attracted or repelled from the magnet 106, else the passage 20 of the magnet between the buffers 104,112 would be impeded.

This plunger configuration is particularly advantageous in that the force acting to open a flow valve in which it is implemented can be increased by up to five times over that of the spring-loaded plunger configuration previously described. This leads to far greater reliability of operation, particularly under very high operating water inlet pressures. The plunger also has improved sensitivity to pressure variations, and is particularly advantageous at controlling slow moving water levels as are found in large volume reservoirs. The valve also is positively acting and does not suffer from 6:6 0 4:'dither', i.e. fast oscillations between open and shut at a change-over position.

The plunger may also be configured for the magnets to act in a repulsive mode rather than an attractive mode. This has the advantage of reducing the travel required by the ring magnet 27 to fully open or close the valve.

Operation of the magnets in a repulsive mode is described with reference to Figs. 8b to 8e. Fig. Sb shows the ring magnet 27 repelling the plunger magnet 106 to urge the plunger magnet downwards to close the vave. In Fig. 8c the ring magnet 27 has lowered due to a drop in reservoir level which lowers the ring magnet which is attached to a float, pressure sensing diaphragm or other device sensing the water level (not shown). As the ring magnet 27 passes the centre line of the plunger magnet 106, the force urging the plunger magnet 106 downwards is reversed and urges the plunger magnet 106 upwards. Fig. Sd shows the plunger 100 forced upwards to the top of its INALIMk100248UFD -13stroke by the repulsive force to open the valve. As the water level in the reservoir rises so then the cylindrical magnet will rise until it reaches the point shown in Fig, 8e where the repulsive force between the ring magnet 27 and the plunger magnet 106 once again changes direction to urge the plunger magnet downwards to close the valve and restore the mechanism to the configuration shown in Fig, 8a.

The plunger 100 can be used in flov, valves generally, including those of the outlet type. Also, it may be appropriate to have a further sealing tip (or like valveseating means) carried by the other end of the plunger body so that the plunger can function in a reciprocating fashion.

Fig. 9 shows another embodiment of an inlet flow valve 120, somewhat similar to that previously described with reference to Figs. 1 and 2. Components of the flow valve in common with the embodiment shown in Figs. 1 and 2 carry a like-reference number.

The basic constructional difference of this flow valve 120 over that shown in Figs. 1 and 2 is that the lower housing 13 has been extended downwardly to o accommodate a deeper outlet tube 122. The lower housing 13 accommodates a dump 9*99 passage 126 having communication between the mid-chamber 19 and a port 128. The ,dump passage incorporates a check valve (one way valve) 124. The port 128 opens out into the outlet tube 122, and also extends to a controlled passage 136 that is in communication with the mid-chamber 19. The port 128 further has a metering threaded *screw 130 controlling the flc- of water through the port.

The upper housing 11 envelopes a tensioning spring arrangement similar to that shown in Fig. 7. A helical spring 132 is restrained between a screw-adjustable end cap 134 that screwably engages an extension piece of the mid-housing 12. The spring 132 fastens at its other end to the rigid disc member 28 carried by the sensing diaphragm 14. The sensing diaphragm 14 and disc member 28 move up and down in operation of the inlet flow valve, and therefore a necessarily water-sealing fit is required between the disc member 28 and the mid-housing 12 so that the water occupying the mid-chamber 19 does not escape to the upper chamber 18.

The inlet flow valve 120 has a continuous self-sensing refilling function between a high water level and a low water level in a tank or reservoir (not shown).

The valve 120 automatically controls filling of the tank or reservoir to the high water level, and restores the water level to that high water level after the low water level is reached through usage of water from the tank or reservoir. This function is achieved as a combination of the location head of pressure difference) of the valve 120 with respect to the tank or reservoir, with the setting of the spring cap 134 (adjusting the energy to be overcome by the sensing diaphragm 14 working against the spring 132), and the setting of the metering screw 130 (to provide a time metered bleed path for water entering the mid-chamber 122 from to the outlet tube 122).

(N:\LIk100248;bFD -14- The situation shown in Fig. 9 has the flow valve 120 closed by the tip 25 of the plunger body to seal off the central orifice 32 in the seat diaphragm 15. The sensing diaphragm 14 is at, its upper-limit of travel acting against the spring 132. This corresponds with the high water level in the supplied tank. The back pressure of water present in the outlet tube 122 is equal to the pressure of water in the mid-chamber 19, hence there is no flow in either the dump passage 126 or the controlled passage 136.

As the level of water in the tank reduces, the back pressure occurring at the outlet tube 122 reduces, hence there is an outflow of water from the mid-chamber 19 via the dump passage 126, thus carrying the sensing diaphragm 14 downwards under the influence of the spring 132. By appropriate configuration of all the adjustment mechanisms, as discussed before, the downward travel of the diaphragm 14 to the point where it engages the end stops 36 corresponds with the low water level in the tank. At this point, the plunger body 24 is captured by the ring magnet 27, and thus the valve is S* 15 open to the flow of inlet water. The flow of refilling water therefore passes to the outlet tube 122 so as to refill the tank. At the same time, the refilling water enters the port 128 and so to the dump passage 126 and control passage 136. The one way valve 124 therefore acts to block the dump passage 126 from the flow of higher pressure inlet water. This means that the only path for the inlet water other than by the outlet tube 122 is via the control passage 136. Adjustment of the metering screw 130 controls the rate of flow of water in the control passage 136 to refill the mid-chamber 19. The metering screw 130 provides a 'time on' function. Once the mid-chamber 19 has been filled to the level shown in Fig. 1, the valve will again close, and if it is the case that the level in the tank has net yet been restored to the high level, the back pressure in the outlet tube 122 will be lower than the pressure existing in the mid-chamber 19, in which case pressure equalisation will occur by the check valve 124 immediately opening and water being dumped from the mid-chamber 19 via the dump passage 126, hence the valve then opens again. Thus valve closing and opening function occurs over a matter of only a few seconds, This configuration of the valve 120 can be used to accurately set the level of water in a reservoir at a distance from the valve. A valve that senses the pressure in the water delivery pipe with water flowing senses the static pressure head of the water in the reservoir together with the pipeline friction losses added to this pressure, Thus the pressure sensed at the valve will be dependant upon the water flow rate and any changes in friction l6sses in the delivery line.

The present valve 120 slops the water flow in the delivery line whilst sensing the pressure, so that only the static pressure head is sensed to give a more accurate measurement of the reservoir level.

IN:\LIBkI00248IFD The process of refilling continues in the same cycle until such time as the high water level is attained and the back pressure in the outlet tube 122 is equal to the pressure of the full mid-chamber 19 and the valve remains closed.

Clearly the setting of the metering screw 130 dictates the number of staged refilling cycles of the flow valve. The flow valve 120 therefore is self-sensing, and typically the flow valve might be set to cycle three times during the refilling operation from the low water level to the high water level.

The flow valve 120 is advantageous in that it does not require a sensing line between it and the tank or reservoir, it can be sited remotely from the tank or reservoir, even at distances of 100 metres, and does not need to be located at the same head of pressure.

Figs. 10a and 10b show a cross-sectional view of an irrigation inlet flow valve 140. The irrigation valve is shown in the open position in Fig. 10a and in the closed 15 position in Fig. 10b. The valve is characterised by having external adjustments for cyclic control over the time the valve is opened time-on) and the time the valve is 5closed time-off). Adjustment of these times by the user are achieved by use of the time-on metering wheel 142 and the time-off metering wheel 144.

Component parts of the flow valve 140 common with the valve shown in Figs.

1 and 2 have been represented by the same reference numerals.

20 The valve 140 receives a supply of inlet water from a pipe or hose 146, and its outlet is connected to an outlet hose or pipe 148. When the valve 130 is open, the typical delivery pressure at both the inlet and outlet is 70 kPa, and when the valve is closed the pressure generated in the inlet hose 136 typically is about 350 kPa.

Operation of the flow valve 140, apart from the time-on and time-off function, is as has been previously described. The sensing diaphragm 14 carrying the disc member 28 acts against a helical compression spring 150. The time-on and time-off functions are governed by the force of water within the mid-chamber 19 acting respectively on a spring loaded check valve 152 and a damped check valve 154, The spring loaded check valve 152 can be opened by the force of water within the midchamber 19 acting against the spring 156 to pass in a metered fashion to the outlet 22 via a passage 158. The damped check valve 154 closes under the pressure of water in the mid-chamber 19, however, a relative negative pressure will cause it to open and allow water to enter the mid-chamber 19 in a metered fashion from the outlet tube 22 via the passage 160.

In the case shown in Fig. 10a, the flow valve 140 has just opened, thus passing water from the inlet tube 21 to the outlet tube 22. As the pressure of water in the supplied tank or reservoir increases, an increased back pressure acts via the outlet tube 22 on both the damped check valve 154 and the spring loaded check valve 152. The spr;ng loaded check valve therefore is forced to cloe, whereas the damped check valve IN:LISk10024!B'FD -16- 154 opens to a degree allowing the commencement of refilling of the mid-chamber 19.

The rate of filling of the mid-chamber 19, and hence the rate of rise of the sensing diaphragm 14, is governed by the damping of the check valve 154 and the metering setting of the time-on metering wheel 142. Once the mid-chamber 19 has filled to the position shown in Fig. 10b, the plunger body 24 closes off the central orifice 32, thus closing the valve.

The sizing of the spring loaded check valve 152 is such that the pressure exerted on that valve by the full volume of water within the mid-chamber 19 is sufficient to overcome the resisting force of the spring 156 and unseat the body 162 thus allowing water to bleed from the mid-chamber 19 in a metered fashion via the passageway 158 to the outlet tube 22. This then causes the sensing diaphragm 14 to lower, in continuation of the cycle, back to the position shown in Fig, In use of the flow valve 140 in, say, an irrigation application, the hose 148 may be connected to a sprinkler or other such device. Therefore, the flow valve 140 acts as a time-on/time-off device that requires no human intervention other than when initially configuring the time-on metering wheel 142 and time-off metering wheel 144 to obtain the desired operational times.

In all the foregoing valves, it often is necessary to incorporate fine mesh S filtering in the various passages within the valve, particularly if the application to which the valve is being put is to control the flow of water or other liquid containing a significant proportion of suspended solids. This particularly may be the case where the various orifices, which are of a size that can easily be clogged by larger ones of the suspended particles must be kept clear to ensure proper functioning of the valves.

Clearly, all the foregoing valves can be used to control the flow of any liquid, and not only water.

In operation of the valves previously described utilising the form of plunger shown in Figs. 8a-8e, it is not necessary for the plunger to act directly on the bleed orifice 32 in the diaphragm. Fig. 11 shows a valve configuration 180 where the water entry from the inlet tube 122 to the upper chamber 20 is through an orifice 31 in the body 182 of the valve and the exit orifice 32 to the outlet tube is also in the body of the valve. The exit orifice 32 is closed by the plunger 100 that extends from the valve body 182 into a float chamber 190 mounted atop the valve body. The float chamber 190 carries a float 192 (that equally could be a diaphragm) carrying one or more permanent magnets 27 as in previous arrangements, and preferably a ring magnet. The level of water in the float chamber 190 is controlled by a sensing line 194 having connection with a reservoir, the level of which is controlled by the flow valve 180.

In operation, when the reservoir level is low to the point of requiring refilling, the float 192 is at a lower position than shown in Fig. 11 capturing the magnet 106 and raising the plunger 100 thus opening the orifice 32. The force of inlet water acting on IN:\LIklOO248MFD -17the underside of the diaphragm is then greater than that above the diaphragm tending to unseat the diaphragm to the. full flow of water, thus refilling the reservoir. When the reservoir reaches the full water mark, the float 192 will have risen upward in the chamber 190 to a point past which the magnet 106 is restrained by an end stop, and the plunger will be released to drop and seal the orifice 32. The pressure of water above the diaphragm will become greater than that acting on the underside thus positively seating the diaphragm on the valve seat 184.

0 ee *go *e IN:\UBkl00248:BFD

Claims (9)

1. A flow control valve for controlling the flow of a liquid to a reservoir, said valve comprising: a valve body having a first chamber therein; an inlet duct in fluid communication with a supply of the liquid, the inlet duct being in fluid communication with the first chamber, the first chamber being partitioned by a seat diaphragm to close off the inlet duct from an outlet of the first chamber, the outlet in turn in fluid communication with an outlet duct and so to the reservoir, the seat diaphragm having an orifice therethrough; a magnetically attractive elongate plunger body resiliently mounted to be urged to close the orifice, the plunger body having an end adapted to close the orifice; and displaceable actuating means carrying permanent magnet means adapted to interact with the plunger body to move the plunger body to open or close the orifice respectively with motion of the actuating means, thereby respectively tending to close or open the flow control valve, wherein the plunger body includes an internal cavity and a magnetically interactive member located within the internal cavity, the member adapted to be slidable along the longitudinal axis of the body between two end travel limits under external magnetic influence of the permanent magnet means so as to impart kinetic energy to the 20 body, the member having a mass that is significant in relation to the mass of the body so as to maximise the impulse of the kinetic energy when the member reaches one of the two end travel limits. i

2. A flow control valve as claimed in claim 1, wherein the plunger body is attractive and/or repulsive to the permanent magnet means.

3. A flow control valve as claimed in claim 1 or 2, wherein the valve body includes an internal cavity partitioned by a sensing diaphragm to define a sensing chamber, the second chamber being in fluid communication with the reservoir whereby •the sensing diaphragm is adapted to move between an upper and a lower limit with the level of the liquid in the reservoir. S" 30

4. A flow control valve as claimed in claim 3 further including a check valve adapted to provide fluid communication from the reservoir to the sensing chamber.

A flow control valve as claimed in claim 3 or 4 further including a metering valve adapted to provide fluid communication between the reservoir and the sensing chamber.

6. A flow control valve as claimed in claim 5 wherein the outlet duct is SR( adapted to provide fluid communication between the reservoir and the check valve and Sthe metering valve. IN:AIibdIOO134:VXF -19-

7. A control valve flow valve as claimed in any one of the preceding claims further comprising a biasing means operable to urge the sensing diaphragm downwardly against the upward urging of te sensing diaphragm in response to the level of the liquid in the reservoir.

8. A flow control valve as claimed in claim 7, wherein the biasing means is a helical spring.

9. A flow control valve as claimed in claim 8, wherein the helical spring is selectively compressingly adjustable. A flow control valve substantially as described herein with reference to Fig. 9 and including a plunger substantially as described herein with reference to Figs. 8a to 8e. DATED this Fifteenth Day of September 1997 Nu-Valve Pty Ltd Patent Attorneys for the Applicant SPRUSON FERGUSON S o SS 0. S oSo o*6 *0oo *o• 0 I IN:\libd00134VXF 4 I t ABSTRACT Improvements in Inlet Floxy Vales An inlet flow valve (60) is mounted within a cistern (40) and receives a supply of water by an inlet tube The inlet tube (21) is in communication with finger-like ducts (65) that supply water to an upper chamber The upper chamber (20) is separated from an outlet chamber (66) by a diaphragm with inlet water passing to the upper chamber via two orifices (31) in the diaphragm. The communication of water from the upper chamber to an outlet chamber (66) through a bleed orifice (32) is closed-off by a spring mounted plunger A float (62) concentrically arranged around the inlet tube (21) carries two magnets (27) that interact with the plunger (24) to unseat the plunger from the orifice in turn, to allow the diaphragm to be unseated and refilling water to pass from the inlet ducts (65) to the outlet chamber the outlet ducts and so to the cistern o. go ~a 0 co 0 *o o* **oee IN\LIBk]00248:BFD