GB2503279A

GB2503279A - Mixer valve

Info

Publication number: GB2503279A
Application number: GB1211101.9A
Authority: GB
Inventors: Kevin Taylor Peel
Original assignee: Kohler Mira Ltd
Current assignee: Kohler Mira Ltd
Priority date: 2012-06-22
Filing date: 2012-06-22
Publication date: 2013-12-25
Anticipated expiration: 2032-06-22
Also published as: GB2503279B; GB201211101D0

Abstract

A mixer valve 1 has inlets 4, 6 for supplies of cold water and hot water and an outlet 8 for water having a desired temperature for washing, showering or bathing. A flow control valve 9 for the cold water and a flow control valve 10 for the hot water control the relative proportions of cold water and hot water admitted to a mixing chamber 11 leading to the outlet 8. Each flow control valve 9, 10 has two outlets and is configured such that water flowing through the flow control valve exerts substantially no net force on a valve member assembly 12, 12' that is movable relative to the outlets for controlling the flows of cold water and hot water.

Description

IMPROVEMENTS IN AND RELATING TO VALVES

This invention relates to valves, especially valves for plumbmg fixtures, fittings and water supply systems and installations for washing, showering, bathing and the like employing such plumbing fixtures and fittings. The invention has particular, but not exclusive, application to a mixer valve, especially a thermostatic mixer valve and, more particularly, to an electronically controlled thermostatic mixer valve. The invention also relates to a flow control valve and to applications of such flow control valve in plumbing fixtures and fittings and parts thereof including, for example, a mixer valve.

A mixer valve receives a fluid flow from at least two sources and provides an output comprising a mix or blend of the sources. Typically, mixer valves are used to control water flow in plumbing fixtures and fittings. In such fixtures and fittings, the mixer valve commonly receives a first input from a cold water supply and a second input from a hot water supply. The mixer valve includes controls that act to control in what proportions the hot and cold supplies are mixed. Thus, the mixer valve mixes the hot and cold supplies in accordance with the setting of its controls to achieve a desired water outlet temperature.

Manually operable thermostatic mixer valves typically include a valve member that is manually adjustable to blend the hot and cold supplies in the correct proportion to set a desired water outlet temperature and a thermostat responsive to the water outlet temperature to adjust the position of the valve member to maintain constant the selected water outlet temperature. The known manually operable thermostatic mixer valves may also provide control of the water outlet flow rate.

An example of such manually operable thermostatic mixer valves is shown in Figures 12 and 13. The mixer valve 101 is designed for mounting on a wall or partition 102 within a shower enclosure and has elbow members 103, 104 either side of a waisted body 105. The elbows 103, 104 are connected to incoming supplies 106, 107 of hot and cold water entering the enclosure through the wall 102.

The body 105 houses a valve mechanism including a valve member that is axially movable between hot and cold seats to control the relative proportions of hot and cold water admitted to a mixing chamber. The valve member is manually adjusted to set the desired outlet water temperature by a rotatablc temperature control knob 110 at the front of the body 105.

The mixing chamber communicates with an outlet 108 in the body. The outlet 108 is shown arranged on the underside of the body 105 when the valve 101 is installed on the wall 102 for connection to a flexible hose that 109 delivers water to a handset. In other arrangements, the outlet may bc arranged on the top of the body 105 when the valve 101 is installed on the wall 102 for connection to a rigid riser pipe that delivers water to a fixed overhead shower.

The valve mechanism includes a thermostat responsive to the water temperature in the mixing chamber to adjust the position of the valve member to maintain constant the selected water temperature. The valve further includes a rotatable tiow control knob 111 mounted concentric with the temperature control knob 110 to control and regulate the flow of water from off to fully open.

Such known valves 101 arc relatively large (the inlets centrcs arc typically spaced 150mm (6 inches) apart) and are often made of metal and therefore relatively heavy and expensive to manufacture.

Electronically controlled thermostatic mixer valves typically utilise motors to control the movement of a valve member to blend the hot and cold supplies in the correct proportion to set a desired water outlet temperature and a temperature sensor responsive to the water outlet temperature to provide a signal to control circuitry to operate the motor to adjust the position of the valve member to maintain constant the selected water outlet temperature.

An example of such electronically operable thermostatic mixer valves is shown in Figures 14 and a mixer unit incorporating the mixer valve is shown in Figure 15. The mixer valve 201 has a body 202 with inlets 203, 204 for connection to supplies of hot and cold water and an outlet 205. The body 202 houses a valve mcchanism including a valve spool 206 having two parts 206a, 206b provided with interlocking castellations that form a series of slotted ports 207.

The inlets 203, 204 open to inlet chambers that surround the spooi 206 and the valve spool 206 is axially movable between a first end position in which the ports 207 communicate with the inlet chamber connected to the cold water supply corresponding to full cold and a second end position in which the ports 207 communicate with the inlet chamber connected to the hot water supply corresponding to full hot. Between the end positions, the ports 207 communicate with both inlet chambers and, adjusting the axial position of the spool 206 between the end positions adjusts the relative proportions of hot and cold water flowing to the outlet 205 and thus the water outlet temperature.

The spool 206 is axially adjustable under the control of a stepper motor 208 that is coupled to the spool 206 by a drive mechanism including a drive rod 209. The stepper motor 208 is controlled by an electronic controller 210 (Figure 15) arranged to receive signals from a user interface (not shown) for selecting the desired water outlet temperature and from a temperature sensor (not shown) mounted in the outlet 205 to adjust the position of the spool 206 to achieve and maintain the desired outlet water temperature.

Such known electronic mixer valves 201 arc relatively large and only control the outlet water temperature not the flow rate. Consequently a separate electronically operable flow control valve 211 is provided with associated controls to start/stop water flow and control the flow rate. The flow control valve 211 has an inlet 212 connected to the outlet 205 of the mixer valve 201. A valve member 213 engages a valve scat 214 to prevent tiow of water from the inlet 212 to an outlet 215 in the closed position of the valve.

The valve member 213 is urged away from the valve seat 214 to open the flow control valve 211 when a solenoid 217 is energised and opening movement of the valve member 213 is controlled by a stepper motor 216 via a drive rod 218 to control the flow rate of water delivered to the outlet 215. The stepper motor 216 is controlled by the electronic controller 210 that receives signals from the user interface for selecting the desired flow rate of the outlet water and from a flow rate sensor mounted in the outlet to adjust the position of the valve member 213 to achieve and maintain the desired outlet water flow rate.

The mixer valve 201 and separate flow control valve 211 are typically combined in a single unit 219 within a housing 220 for connection to the electrical supply for the stepper motors. The large size of the units 219 renders them unsuitable for mounting in a shower enclosure. As a result, they are usually mounted remote from the shower enclosure, for example in the ceiling above the shower enclosure with the outlet 215 supplying connecting pipework to deliver outlet water to an overhead shower, a handset or other spray device within the shower enclosure and with a wired or wireless connection from the user interface located in the shower enclosure to the electronic controls for the mixer valve and flow control valve.

Due to the size and complexity of many parts of the mixer valve and how control valve that form the water way and come into contact with the water, such parts are made of plastics materials to facilitate manufacture and reduce the weight of the units.

The use of plastics materials however gives rise to a health risk from the presence of harmful micro-organisms in the water supply, especially bacteria and in particular legionella bacteria. The bacteria readily form a bio-film on surfaces of the waterway in contact with the water that are made of plastics material and the growth of bacteria forming the bio-film is promoted in the warm water present in the waterways, especially immediately after use while the water remaining in the valve is still warm and before it has cooled down. The large surface area of the waterways in the known electronically controlled mixer valves therefore presents a particular problem for effective control of bacteria to reduce the risk of users being infected by bacteria in the fine droplets of water present in the shower area when showering and which can be readily inhaled.

It is known to periodically flush the waterways with hot water for a pre-determined period of time, typically at least 65°C for at least 10 minutes, to kill bacteria present on the surface of the waterways. However, if the water used is not hot enough or is not present for a sufficient period of time the bacteria can survive and continue to grow.

Also flushing with hot water may not remove bacteria present on the surface of the waterway in trapped areas of the waterway that are not flushed by the hot water. This can be a further problem affecting the efficient removal of bacteria in complex waterways made of plastics niaterials.

Hence a need exists for improved valves for plumbing fixtures, fittings and water supply systems and installations for washing, showering, bathing and the like employing such plumbing fixtures and fittings.

According to an exemplary embodiment, a mixer valve includes a first fluid inlet adapted to receive a first fluid, a second fluid inlet adapted to receive a second fluid, a fluid outlet adapted to output the first fluid or the second fluid or a mixture thereot and a first flow control valve for controlling the flow of fluid from the first fluid inlet and a second flow control valve for controlling the flow of fluid from the second fluid inlet, each of the first and second flow control valves including a valve member assembly to control the tluid flow through the respective flow control valvc, the valve member assembly and the fluid inlet of each of the first and second flow control valves being adapted and arranged such that, when in use, fluid flowing through the first flow control valve exerts substantially no net force on the valve member assembly of the first flow control valve and fluid flowing through the second flow control valve exerts substantially no net force on the valve member assembly of the second flow control valve.

By the term "substantially no nct force" we mean that the valve member assembly is essentially "force balanced" with respect to the fluid flow. In other words, the force required to actuate the valve member assembly when controlling the valve is substantially independent of fluid flow. As a result, the actuating force can be reduced compared to valves where there is a significant imbalance of the forces due to fluid flow.

Reducing the actuating force to operate the valve member assembly may enable the actuator to be made smaller than would otherwise be possible with potential cost and cnergy savings. Consequently, the mixer valve itself may be made smaller (because less power is required to operate the valve member assembly) than would otherwise be possible in existing mixer valves.

By reducing the size of the mixer valve, the size of the waterways within the mixer valve and thus the volume of water present in the mixer valve and the available surface area in contact with the water for bio-film to form and bacteria to grow can be reduced. Also the occurrence of trapped areas in the waterways where water can collect and promote growth of bacteria may be reduced. Furthermore, by reducing the size of the mixer valve, it may be possible to manufacture the mixer valve, especially parts forming the waterways, from metal rather than plastics. The use of metals can have further benefits for controlling the growth of bacteria. Thus, bio-films form more readily on plastics than metal and bacteria are killed by contact with certain metals, especially metal alloys containing copper such as brass.

It will be understood that reducing the effect of fluid flow on the valve member assembly is an important factor in reducing the size of the mixer valve by reducing the actuating force required to operate the valve member assembly. While it may therefore be desirable to eliminate the effect of tluid flow on the valve member assembly altogether, it may for practical reasons not always be possible to achieve.

Accordingly, while the aim may be to reduce any imbalance of the forces acting on the valve member assembly due to fluid flow when designing the mixer valve, the benefits and advantages of reduced actuating force and thus reduced size (power) of the actuator and reduced size of the mixer valve may still be achieved to a large extent even if some imbalance of the forces acting on the valve member assembly due to fluid flow is present.

In some eases, it may even be desirable to have a small imbalance of the forces acting on the valve member assembly due to fluid flow. For example, a small imbalance of the forces may be utilised to hold the valve member assembly closed without relying on the actuator. In this way, it may not be necessary to provide power to the actuator when the mixer valve is closed with consequential saving in energy costs.

Accordingly we intend the term "substantially no net force" to include not only situations where there is no imbalance of the forces acting on the valve member assembly due to fluid flow i.e. fully force balanced", but also situations where some imbalance of the forces is present whether by design or not provided that such imbalance does not result in a significant increase in the size (power) of the actuator.

The actual force required to operate the flow control valves when fully force balanced may depend on various factors including, but not limited to * the size of the valve and/or of the valve member assembly, * the number, materials and arrangement of seals provided between the valve members and the valve seats * the number, materials and arrangement of seals provided between the spool and the housing, Thus, for a given valve, it may be that in some embodiments a level of imbalance of up to + 10% of the actuating force when fully force balanced may be present while in other embodiments a level of imbalance of up to ± 5°% of the actuating force when fully force balanced may be present and in yet further embodiments a level of imbalance of the actuating force when fully force balanced of up to + 2% may be present.

According to an exemplary embodiment, each flow control valve compriscs a valve inlet for receiving fluid from one of the first or second fluid inlets, the valve member assembly including a first valve member adapted to engage with a first valve seat in a closed position of the flow control valve and a second valve member adapted to engage with a second, separate, valve seat in the closed position of the flow control valve, the first valve member being arranged to be urged closed by fluid entering through the valve inlet and the second valve member being arranged to be urged open by fluid entering through the valve inlet.

This is advantageous because, when in use, the force exerted by the fluid on each of the valve members can be balanced (as discussed herein) such that the actuating force to move the valve members from thcir respective valve seats can bc reduced.

According to an exemplary embodiment, each valve inlet is located between the first valve member and the second valve member of each of the first and second flow control valves. For example, according to one particular exemplary embodiment, the valve inlet is configured to open into an inlet chamber defined by a chamber wall having a first valve outlet and a second valve outlet formed therein. The first valve seat may be associated with the first valve outlet and the second valve seat may be associated with the second valve outlet.

According to an exemplary embodiment, the mixer valve includes a mixing chamber that includes the fluid outlet, the mixing chamber being arranged to receive fluid from

S

the first and second fluid outlets of thc flow control valves. This is advantageous as it has been found that a high flow rate can be achieved even when the valve is miniaturised (i.e., reduced in size).

According to an exemplary embodiment, the first and second valve outlets may be of similar size. In some embodiments, the first and second valve outlets may be the same size. This is advantageous as it been found to assist balancing the valve assemblies (as discussed herein). Furthermorc, using two outlets we can achieve flow rates comparable with using a single, larger outlet, thereby allowing the valve to be miniaturised (i.e. reduced in size).

According to an exemplary embodiment, the first valve member and second valve member are connected by a spool. In particular, the valve members may be fixedly mounted to the spool. According to an exemplary embodiment, the spool may be coupled to an actuator which controls the position of the valve members relative to their respective valve seats. According to an exemplary embodiment, the actuator comprises an electrically-powered motor. The actuator may comprise a stepper motor.

It may bc that the motor can be very low power as the double valve member design ensures that the valve member assembly is substantially balanced against the force exerted by the fluid (as discussed herein). Thus, only a small actuation force is required. The stepper motor may be connected to the spool such that rotational motion of the stepper motor causes linear motion of the spool. Any suitable actuator for controlling linear motion of the spool may be employed including, but not limited to, linear actuators.

According to an exemplary embodiment, the first and second valve seats may be located within the valve outlets. For example, the valve seats may include a cylindrical bore portion of the valve outlets in which the valve members are slidably received in the closed position. This is advantageous as the spoo1 carrying the valve members can be fitted from one end of the valve by inserting the spool and valve members from one end of the inlet chamber through onc of the valve outlets to engage the other valve outlet at the opposite end of the inlet chamber.

According to a different exemplary embodiment, the first and second valve seats may bc located at onc end of the valve outlets. For example, the valve seats may include an end face of the valve outlets against which the valve members seat in the closed position.

According to an exemplary embodiment, the first valve member may be received in the valve inlet chamber in an open position of the flow control valve and the second valve member may be received in the mixing chamber in the open position of the flow control valve. In this way, the first valve member nioves away from its valve seat to open the valve outlet against the direction of fluid flow and the second valve member moves away from its valve scat to open the valve outlet in the direction of fluid flow.

Thus fluid flow assists opening movement of the second valve member and opposes opening movement of the first valve member. The effect of the fluid flow on each valve member is reversed whcn moving the valve members towards their valve scats to close the valve outlets. The fluid forces acting on the valve members can be balanced (as discussed herein) when the valve outlets and valve members are matched, i.e. of similar size, so that the actuator to operate the valve member assembly does not have to overcome a significant force imbalance due to fluid flow both when opening and closing the valve. This is advantageous as the actuation force is substantially independent of fluid flow and the actuator can be smaller than would otherwise be necessary.

According to an exemplary embodiment, the mixer valve comprises a valve housing that houses the flow control valves. The housing may include apertures that form the first fluid inlet, second fluid inlet, and fluid outlet.

According to an exemplary embodiment, the housing may be made of metal or alloy, especially alloys containing copper such as brass to kill harmful micro-organisms present in the fluid. An electrically powered heating device may be provided for thermally disinfecting the mixer valve. The mixer valve may be disabled during a thermal disinfection cycle to prevent discharge of fluid. The thermal disinfection cycle may include a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and optionally a cool down cycle to allow the housing and fluid contained in the valve to cool down after the heating cycle.

According to an exemplary embodiment, the first and second flow control valves are connected to supplies of hot and cold water and are controlled in response to outlet water temperature and/or flow rate. In one exemplary arrangement, a sensor device may be arranged to measure tile temperature and/or flow rate of tile outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate. In another exemplary arrangement, a sensor device may be arranged to measure the temperature of the supplies of hot and cold water and/or flow rate of the outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.

According to another exemplary embodiment, a mixer valve includes a first inlet for receiving a first fluid, a second inlet for receiving a second fluid, and a mixing chamber having a fluid outlet for outputting the first fluid or the second fluid or a is mixture thereof, the mixer valve including a first flow control valve for controlling the flow of the first fluid into the mixing chamber and a second flow control valve, separate from the first flow control valve, for controlling the flow of the second fluid into the mixing chamber, wherein at least the first or second flow control valve includes at least two, separatc outlets into the mixing chamber.

This is advantageous as the separate outlets ensure that a substantial flow rate can be maintained through the mixer valve even when it is miniaturised. The first inlet typically receives cold water from a cold water supply and the second inlet typically receives hot water from a hot water supply.

According to an exemplary embodiment, at least the first or second flow control valve includes a valve member assembly to control the flow through the control valve that is balanced (as discussed herein) such that fluid flowing through thc control valve exerts substantially no net force on the valve member assembly. This is advantageous as the force required to actuate the valve member assembly when controlling the mixer valve is small. Accordingly, the actuator for moving the valve member assembly and the mixer valve itself can be miniaturised (i.e. reduced in size).

According to an exemplary embodiment, both the first flow control valve and the second how control valve each include at least two separate outlets into the mixing chamber. According to an exemplary embodiment, each flow control valve is defined by an elongate valve inlet chamber having a valve inlet and two separate outlets formed at substantially opposite ends of the valve inlet chamber. Thus, each flow control valve controls the flow between the associated valve inlet chamber and the mixing chamber.

According to an exemplary embodiment, each flow control valve includes a valve member assembly including a first valve member adapted to engage with a first valve seat associated with a first of the two outlets and a second valve member adapted to engage with a second, separate, valve seat associated with a second of the two outlets in the closed position of the flow control valve.

The first valve member may be arranged to be urged closed by fluid entering the valve inlet chamber through the valve inlet and the second valve member may be arranged to be urged open by fluid entering the valve inlet chamber through the valve inlet. Thus the first and second flow control valves can be balanced (as discussed herein) due to the dual valve member design. The two outlets and two valve members ensure a substantial flow rate can be achieved while ensuring the valve members are fluid flow force balanced (as discussed herein) to aid miniaturisation.

According to an exemplary embodiment, the first valve member and second valve member are connected by a spool. The valve members may be fixedly mounted to the spool. According to an exemplary embodiment, the spool is connected to an actuator, which controls the position of the valve members relative to their respective valve seats. Thc actuator may be an electrically powered motor, for example a stepper motor. The actuator motor can be very low power as the double valve member design ensures that the valve is balanced (as discussed herein) against the force exerted by the fluid. Thus, only a small actuation force is required. Accordingly, thc stepper motor and thus the mixer valve itself can be very small compared to prior art designs.

According to an exemplary embodiment, the first and second valve outlets may be of similar size. According to an exemplary embodiment, the first and second valve outlets can be the same size. According to an exemplary embodiment, the first and second valve outlets may be axially aligned.

In some embodiments, the valve seats may be located within the valve outlets. For example, the valve seats may include a cylindrical bore portion of the valve outlets in which the valve members are slidably received in the closed position. This is advantageous as the spool carrying the valve members can be fitted from one end of the valve by inserting the spool and valve members from one end of the inlet chamber through one of the valve outlets to engage the other valve outlet at the opposite end of the inlet chamber.

In other embodiments, the valve seats may be located at one end of the valve outlets.

For example, the valve seats may include an end face of the valve outlets against which the valve members seat in the closed position.

According to an exemplary embodiment, the first valve member may be received in the valve inlet chamber in an open position of the flow control valve and the second valve member may be received in the mixing chamber in the open position of the flow control valve. In this way, the first valve member moves away from its valve seat to open the valve outlet against the direction of fluid flow and the second valve member moves away from its valve seat to open the valve outlet in the direction of fluid flow.

Thus fluid flow assists opening movement of the second valve member and opposes opening movement of the first valve member. The effect of the fluid flow on each valve member is reversed when moving the valve members towards their valve seats to close the valve outlets. The fluid forces acting on the valve members can be balanced (as discussed herein) when the valve outlets and valve members are matched, i.e. of similar size, so that the actuator to operate the valve member assembly does not have to overcome a significant force imbalance due to fluid flow both when opening and closing the valve.

According to an exemplary embodiment, the mixer valve includes a housing that houses the first and second flow control valves and includes apertures that forni the first fluid inlet, second fluid inlet and fluid outlet.

According to an exemplary embodiment, the housing may be made of metal or alloy, especially alloys containing copper such as brass to kill harmful micro-organisms presenl in the fluid. An electrically powered heating device may be provided for thermally disinfeeting the mixer valve. The mixing valve may be disabled during a thermal disinfection cycle to prevent discharge of fluid. The thermal disinfection cycle may include a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and optionally a cool down cycle to allow the housing and fluid contained in the valve to cool down after the heating cycle.

According to an exemplary embodiment, the first and second flow control valves are connectcd to supplies of hot and cold water and are controlled in response to outlet water temperature and/or flow rate. In one exemplary arrangement, a sensor device may be arranged to measure the temperature and/or flow rate of the outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate. In anothcr exemplary arrangement, a sensor device may be arranged to measure the temperature of the supplies of hot and cold water and/or flow rate of the outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.

According to another exemplary embodiment, a plumbing fitting may be configured to receive a mixer valve such as those described in the present application.

According to an exemplary embodiment, the plumbing fitting comprises a fluid delivery device. According to an exemplary embodiment, the fluid delivery device is a shower head. According to another exemplary embodiment, the fluid delivery device is a faucet such as a bath tap, sink tap and basin tap. As the mixer valve can be easily miniaturiscd (i.e. reduced in size), it can be placed within plumbing fittings where it was previously not possible to do so or doing so would have made the fitting large and/or heavy and/or cumbersome to use.

Thus, a showcr system may simply comprise a shower head that receives both hot and cold water supplies through two conduits wherein the mixer valve is housed within the shower head and delivers water to an outlet of the shower head. The mixer valve niay be controlled via a control device such as a user interface which may be incorporated in the shower head or provided separately and connected to the shower head via a wired or wireless link. The interface niay provide control signals to an electronic controller that controls the actuators for the flow control valves according to user selected inputs of temperature and/or flow rate and/or outlet, for example where the shower system has multiple outlets. The electronic controller may receive inputs of the actual temperature of the outlet water and/or the inlet water and/or flow rate from appropriately positioned sensors and control the actuators for the flow control valves in response thereto to achieve and maintain the user selected settings. The electronic controller may include a microprocessor. The microprocessor may be programmable and may include a memory.

Likewise, a fluid delivery system may comprise a faucet that receives both hot and cold water supplies through two conduits wherein the mixer valve is housed within the faucet and delivers water to an outlet of the faucet which may, in use, project over a bath, a sink or a basin. The mixer valve may be controlled via a control device such as a user interface which may be incorporated in the faucet or provided separately and connected to the faucet via a wired or wireless link. The interface may provide control signals to an electronic controller that controls the actuators for the flow control valves according to user selected inputs of temperature and/or flow rate and/or outlet, for example where the faucet has multiple outlets. The electronic controller may receive inputs of the actual temperature of the outlet water and/or the inlet water and/or flow rate from appropriately positioned sensors and control the actuators for the flow control valves in response thereto to achieve and maintain the user selected settings. The electronic controller niay include a microprocessor. The microprocessor may be programmable and may include a memory.

According to another exemplary embodiment, a shower head is configured to receive a first fluid conduit and a second fluid conduit, wherein the shower head includes a mixer valve adapted to receive a first fluid from the first fluid conduit and a second fluid from the second fluid conduit and output the first fluid or the second fluid or a blend of the first and second fluids to a shower head outlet. According to an exemplary embodiment, the mixer valve may be such as those described in the present application.

According to an exemplary embodiment, the shower head includes a stem or body portion to receive the first and second conduits and at least one outlet to discharge fluid received from the mixer valve. The stern portion rnay include a body having a duet therein for a fixed shower head or a handle having a duct therein for a moveable shower head. The duet may carry first and second fluid conduits. The mixer valve may be such as those described in the present application.

According to an exemplary embodimcnt, the shower head may be provided with a spray head having a single outlet provided with a spray plate having an array of holes for discharging water. The array of holes may be configured to discharge water in any selected one of a plurality of spray patterns.

According to another exeniplary embodiment, the shower head is provided with a spray head having a plurality of outlets and the spray head is adjustable to select any one of the outlets or a combination of outlets for discharging water.

According to another exemplary embodiment, a fluid delivery device is configured to receive a first fluid conduit and a second fluid conduit, wherein the fluid delivery device includes a mixer valve adapted to receive a first fluid from the first fluid conduit and a second fluid from the second fluid conduit and output the first fluid or the second fluid or a blend of the first and second fluids to an ourlet of the fluid delivery device. The mixer valve may be such as those described in the present application According to an exemplary embodiment, the fluid delivery device includes a body portion to receive the first and second conduits and an outlet to discharge fluid received from the mixer valve. The fluid delivery device may include a faucet. The faucet may comprise a tap selected from the group comprising a bath tap, a sink tap and a basin tap.

According to an exemplary embodiment, the body por ion includes a base por ion and a stem portion (sometimes referred to as a "spout") provided with the outlet for discharging water. The mixer valve may be located in the stem portion. This is advantageous because previous mixer taps required the mixer valve to be located in the base of the faucet rather than the spout or even separate from the faucet altogether.

The mixer valves as described herein can be miniaturised (i.e. reduced in size) such that it can be located in the stem portion, adjacent to, or within the outlet of the faucet. The faucet need not have controls at its base as the faucet can simply comprise the stern portion.

The stem portion may be movable according to an exemplary embodiment. For example, it may be arranged to pivot about its base. Kitchen taps, for example, commonly have movable stem portions. The mixer valves as described in the present application can be provided or mounted in the movable stem portion and not in a fixed

valve base as in prior art tap designs.

The flow control valves disclosed in the present application may be used individually as flow control valves according to an exemplary embodiment.

According to another exemplary embodiment, a flow control valve includes a valve inlet adapted to receive a fluid, a valve outlet adapted to output the fluid, the flow control valve including a valve member assembly to control the fluid flow through the flow control valve, wherein the valve member assembly and the valve inlet are adapted and arranged such that, when in use, fluid flowing through the flow control valve exerts substantially no net force on the valve member assembly.

According to an exemplary embodiment, the valve member assembly comprises a first valve member adapted to engage with a first valve seat in a closed position of the flow control valve and a second valve member adapted to engage with a second, separate, valve seat in the closed position of the flow control valve, wherein the first valve member is arranged to be urged closed by fluid entering through the valve inlet and the second valve member is arranged to be urged open by fluid entering through the valve inlet.

This is advantageous because the force exerted by the fluid on each of the valve members can be balanced (as discussed herein) such that the valve requires a small force to move the valve members from their respective valve seats.

According to an exemplary embodinient, the valve inlet is located between the first valve member and the second valve member. The valve inlet may open into an inlet chamber defined by a chamber wall having a first valve outlet and a second valve outlet formed therein. The first valve seat may be associated with the first valve outlet and the second valve seat may be associated with the second valve seat.

According to an exemplary cmbodimcnt, thc valve includes an outlet chamber that includes the fluid outlet with the outlet chamber being arranged to receive fluid from the first and second valve outlets of the inlet chamber. The first and second valve outlets may be of similar size. Thc first and second valve outlets may be axially aligned, for example at opposite ends of the inlet chamber.

According to an exemplary embodiment, the first valve member and second valve member are connected by a spool. In particular, the valve members may be fixedly mounted to the spool. According to an exemplary embodiment, the spool is connected to an actuator which controls the position of the valve members relative to their respective valve seats.

According to an exemplary embodiment, the actuator includes an electrically-powered motor. The actuator may comprise a stepper motor. The motor can be very low power as the double valve member design ensures that the valve is balanced (as discussed herein) against the force exerted by the fluid. Thus, only a small actuation force is required. The stepper motor may be connected to the spool such that rotational motion of the stepper motor causes linear motion of the spool. Any suitable actuator for controlling linear motion of the spool may be employed including, but not limited to, linear actuators.

According to an exemplary embodiment, the valve seats are located within the valve outlets. The valve seats may include a cylindrical bore portion of the valve outlets in which the valve members are slidably received in thc closed position.

According to an exemplary embodiment, the valve seats are located at one end of the valve outlets. The valve seats may include an end face of the valve outlets against which the valve members seat in the closed position.

According to an exemplary enibodiment, the first valve member is received in the valve inlet chamber in an open position of the flow control valve and the second valve member is received in the outlet chamber in the open position of the flow control valve. In this way, the first valve member moves away from its valve seat to open the valve outlet against the direction of fluid flow and the second valve member moves away from its valve seat to open Ihe valve oullet in the direction of fluid how.

Thus fluid flow assists opening movement of the second valve member and opposes opening movement of the first valve member. The effect of the fluid flow on each valve member is reversed when moving the valve members towards their valve seats to close the valve outlets. The fluid forces acting on the valve members can be balanced (as discussed herein) when the valve outlets and valve members are matched, i.e. of similar sizc, so that the actuator to operate the valve member assembly does not have to overcome a significant force imbalance due to fluid flow both when opening and closing the valve.

According to an exemplary embodiment, the flow control valve includes a valve housing that houses the valve member assembly. The housing may have apertures that form the fluid inlet and fluid outlet.

According to an exemplary embodiment, the housing may be made of metal or alloy, especially alloys containing copper such as brass to kill harmful micro-organisms present in the fluid. An electrically powered heating device may be provided for thermally disinfccting thc flow control valve. The flow control valve may be disabled during a thermal disinfection cycle to prevent discharge of fluid. The thermal disinfection cycle includes a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and a cool down cycle to allow the housing and fluid contained in the valve to cool down after the heating cycle.

According to another exemplary embodiment, a flow control valve includes an inlet for receiving a fluid, and an outlet chamber having an outlet for outputting the fluid, the flow control valve controlling the flow of fluid into the outlet chamber, wherein the flow control valve includes at least two, separate valve outlets into the outlet chamber.

This is advantageous as the separate outlet apertures ensure that a substantial flow rate can be maintained through the valve even when it is miniaturised (i.e. reduced in size).

According to an exemplary embodiment, thc flow control valvc includes an elongate inlet chamber having the inlet and two separate valve outlets formed at substantially opposite ends of the inlet chamber.

According to an exemplary embodiment, the flow control valve includes a valve member assembly to control the flow through the control valve that is balanced (as discussed herein) such that fluid tiowing through the control valve exerts substantially no net force on thc valve member assembly. This is advantageous as the force required to actuate the valve member assembly when controlling the valve is small.

Accordingly, the actuator for moving the valve member assembly and the valve itself can be miniaturised (i.e. reduced in size).

According to an exemplary embodinient, the valve nieniber assembly includes a first valve member adapted to engage with a first valve seat associated with a first of the at least two valve outlets in a closed position of the flow control valve and a second valve member adapted to engage with a second, separate, valve seat associated with a second of the at least two valve outlets in the closed position of the flow control valve.

According to an exemplary enibodiment, the first valve member is arranged to be urged closed by fluid entering through the inlet chamber through the inlet and the second valve member is arranged to be urged open by fluid entering the inlet chamber through the inlet. Thus the flow control valve can be balanced (as discussed herein) due to the dual valve member design. The two outlets and two valve members ensure a substantial flow ratc can be achieved.

According to an exemplary embodiment, the valve inlet is located between the first valve member and the second valve member. The valve inlct may open into the inlet chamber defined by a chamber wall in which the first valve outlet and the second valve outlet are formed.

According to an exemplary embodiment, the first valve member and second valve member are connected by a spool. The valve members may be fixedly mounted to the spool.

According to an exemplary embodiment, thc spool is coupled to an actuator which controls the position of the valve members relative to their respective valve seats. The actuator motor may comprise an electrically powered motor and can be very low power as the double valve member design ensures that the valve is balanced against the force exerted by the fluid. Thus. only a small actuation force is required.

Accordingly, a stepper motor can be used and thus the flow control valve itself can be

very small compared to prior art designs.

According to an exemplary embodiment, the first and second valve outlets are of similar size. The first and second valve outlets may be axially aligned.

According to an exemplary embodiment, the valve seats are located within the valve outlets. For example, the valve seats may include a cylindrical bore portion of the valve outlets in which the valve members are slidably received in the closed position.

According to an exemplary embodiment, the valve seats are located at one end of the valve outlets. For example, the valve seats may include an end face of the valve outlets against which the valve members seat in the closed position.

According to an exemplary embodiment, the first valve member is received in the inlet chamber in an open position of the flow control valve and the second valve member is received in the outlet chamber in the open position of the flow control valve.

According to an exemplary embodiment, the flow control valve includes a housing that includes apertures that form the fluid inlet and fluid outlet.

According to an exemplary embodiment, the housing may be made of metal or alloy, cspecially alloys containing copper such as brass to kill harmful micro-organisms present in the fluid. An electrically powered heating device may be provided for thermally disinfecting the flow control valve. The flow control valve niay be disabled during a thermal disinfection cycle to prevent discharge of fluid. The thermal disinfection cycle may include a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and optionally a cool down cycle to allow the housing and fluid contained in the valve to cool down after the heating cycle.

According to an exemplary embodiment, a method of controlling flow rate and/or temperature of outlet water from a mixer valve having first and second flow control valves is provided. The method includes connecting the first flow control valve to a first water supply, connecting the second flow control valve to a second water supply, wherein the first and second water supplies have different temperatures, configuring the first and second flow control valves so that an operating force to actuate the flow control valves is substantially independent of water flow, and controlling the first and second flow control valves separately or in combination and outputting a flow of the first water supply or the second water supply or a blend of the first and second water supplies having a desired flow rate and/or temperature.

According to an exemplary embodiment, the first and second flow control valves each include a valve member assembly configured such that, when in use, fluid flowing through the valve exerts substantially no net force on the valve member assembly.

According to an exemplary embodiment, the first and second flow control valves each include a valve inlet chamber to receive water from the associated water supply and having first and second outlets opening to a mixing chamber.

According to an exemplary embodiment, the first and second outlets are arranged at opposite ends of the inlet chamber and are axially aligned and provide first and second valve seats for co-operating with first and second valve members connected to a common spool coupled to an actuator for adjusting the first and second valve members relative to the first and second valve seats for controlling flow of water from the inlet chamber to the outlet chamber.

According to an exemplary embodiment, in use, fluid flowing through each flow control valve exerts a force on each valve member wherein the force on the first valve member is substantially equal to and in the opposite direction to the force exerted on the second valve member.

According to an exemplary embodiment, the outlet water is supplied to an outlet of a water delivery device. The water delivery device may be a shower head or a faucet.

The faucet may be selected from a bath tap, a sink tap and a basin tap.

According to an exemplary embodiment, a method of controlling flow rate of outlet water from a flow control valve is provided. The method includes connecting the flow control valve to a water supply, configuring the flow control valve so that an operating force to actuate the flow control valve is substantially independent of water flow, and controlling the flow control valve to output a flow of the water having a desired flow rate.

According to an exemplary embodiment, the flow control valve includes a valve member assembly configured such that, when in use, fluid flowing through the valve exerts substantially no net force on the valve member assembly.

According to an exemplary embodiment, the flow control valve includes a valve inlet chamber to receive water from the water supply and having first and second outlets opening to an outlet chamber.

According to an exemplary embodiment, wherein the first and second outlets are arranged at opposite ends of the inlet chamber and arc axially aligned and provide first and second valve seats for co-operating with first and second valve members connected to a common spool coupled to an actuator for adjusting the first and second valve members relative to the first and second valve seats for controlling flow of water from the inlet chamber to the outlet chamber.

According to an exemplary embodiment, in use, fluid flowing through the flow control valve exerts a force on each valve member wherein the force on the first valve member is substantially equal to and in the opposite direction to the force exerted on the second valve member.

The faucet may be selected from a bath tap, a sink tap and a basin tap.

Other features, benefits and advantages of the mixer valve and flow control valve described herein will be apparent from the description hereinafter of exemplary embodiments thereof and of the application of the mixer valve and flow control valve to plumbing fixture and fittings and water supply systems and installations employing such plumbing fixtures and fittings. Such description is provided for the purpose of demonstrating the diverse ways in which the mixer valve and flow control valve can be configured and used and is not intended to be limiting on the scope of the

disclosure.

There now follows by way of example only a detailed description of various exemplary embodiments disclosed in the present application, with reference to the accompanying drawings, iii which; Figure 1 shows a view of an embodiment of a mixer valve; Figure 2 shows a cross-sectional view of the mixer valve shown in Figure 1; Figure 3 shows a more detailed view of the flow control valves shown in Figure 2; Figure 4 shows the mid-open position of the flow control valve shown in Figures Ito 3; Figure 5 shows a perspective view of another embodiment of a mixer valve; Figure 6 shows a sectional view of the mixer valve of Figure 5: Figure 7 shows a perspective view of another embodiment of a mixer valve; Figure 8a shows a plumbing fitting comprising a shower head incorporating an embodiment of the mixer valve disclosed herein; Figure 8b shows a cut-away view of the shower head shown in Figure Sa showing the mixer valve therein; Figure 9a shows a plumbing fitting comprising a faucet incorporating an embodiment of the mixer valve disclosed herein; Figure 9b shows a cut away view of thc faucet shown in Figure 9a showing thc mixcr valve therein; Figure 10 shows a further plumbing fitting comprising a shower head incorporating an embodiment of the mixer valve disclosed herein; Figure ha shows a further embodiment of a plumbing fitting comprising a bar mixcr assembly incorporating an embodiment of the mixer valve disclosed herein; Figure lib shows a top view of the bar mixer assembly with the control panel reino v e d; Figure lic shows a detailed view of one of the tiow control valves of the bar mixcr assembly shown in Figurc I Ib; Figure 12 shows a front view of a prior art mixer valve: Figure 13 shows an underneath plan view of the prior art mixer valve of Figure 12; Figure 14 shows a side view of a prior art electronic mixer valve; and Figure 15 shows a side view of a unit containing the prior art electronic mixer valve shown in Figure 14.

Figures 1 to 4 show an embodiment of a mixer valve for use in controlling the mixing of two supplies of water having differcnt temperatures (nominally hot and cold water supplies) and outputting water having a desired temperature for use. The valve may also control flow rate of the output water. The mixer valve may be incorporated into a plumbing fixture or fitting for washing, showering, bathing or the like and water supply systems and installations employing such plumbing fixtures and fittings. For example, the mixer valve may be incorporated in a faucet for a basin, sink, shower bath or the like. The mixer valve may be incorporated in a water supply system or installation having one or more outlets for washing, showering, bathing or the like.

Each outlet may include a faucct incorporating the mixer valve. Alternatively, the mixer valvc may be incorporated in a fitting supplying more than one outlet. For example multiple shower heads may be supplied with water from one mixer valve.

Other applications and uses of the mixer valve will be apparent to those skilled in the art from the description of the invention provided herein and the invention extends to and includes all modifications and changes within the spirit and scope of the

disclosure.

Figure 1 shows the mixer valve 1 enclosed within a valve housing 2. An aperture 3 in the housing 2 forms a first fluid inlet 4 for receiving a first fluid (cold water in this cmbodiment). Similarly, as shown in Figure 2, the housing 2 includcs a further aperture 5 that forms a second fluid inlet 6 for receiving a second fluid (hot water in this embodiment) and a still further aperture 7 that forms a fluid outlet 8 for outputting the first fluid or the second tluid or a mixture thereof.

Figures 2, 3 and 4 show the mixer valve 1 in cross section. The mixer valve I includes a first flow control valve 9 and a second flow control valve 10 located within a mixing chamber 11. The first flow control valve 9 controls the flow of fluid from the first fluid inlet 4 to the mixing chamber 11. The second flow control valve 10 controls the flow of fluid from the second fluid inlet 6 to the mixing chamber 11. The mixing chamber 11 provides a volume in which the first and second fluids can mix and directs the mixed fluid to the fluid outlet 8.

The first and second flow control valves 9, 10 are similar and arc arranged side by side in parallel and on opposite sides of the mixing chambcr 11. There follows a description of the construction and operation of the first flow control valve 9 and the same reference numerals have been used but with an additional apostrophe to identify similar features of the second flow control valve 10 such that the construction and operation of the second flow control valve 10 will be apparent and understood from

the description of the first flow control valve 9.

The first foxy control valve 9 includes a valve member assembly 12, a valve inlet chamber 13 and first and second valve outlets I 4a and I 4b. The inlet chamber 13 is substantially cylindrical. The first fluid inlet 4 opens into the inlet chamber 13 through the side wall of the inlet chamber 13 (the second inlet 6 opens into the valve inlet chamber 13' of the second flow control valve 10 through the side wall of the inlet chamber 13').

The first valve outlet 14a is arranged at one end of the inlet chamber 13 and the second valve outlet 14b is arranged at an opposed end of the inlet chamber 13. Each of the valve outlets 14a and 145 includes a through bore with a cylindrical centre section 15 of reduced diameter relative to the end sections 16, 17. The bore is tapered between the centre section 15 and the end sections 16, 17. The valve outlets 14a and 1 4b are axially aligned and in tlus embodiment the centre sections 15 of the outlets l4a and 14b are coaxial and have the same diameter. The valve member assembly 12 controls the flow of water through the first flow control valve 9 from the inlet chamber 13 to the mixing chamber 11.

The valve member assembly 12 comprises a first valve member iSa adapted to co-operate with the first valve outlet 14a and a second valve member lSb adapted to co-operate with the second valve outlet 14b to control flow of water from the inlet chamber 13 to the mixing chamber 11. The first and second valve members I Sa, 155 are fixedly mounted on a spool 19 such that they arc held a predetermined distance apart. The predetermined distance corresponds to the distance between the first and second valve outlets 14a, 145.

The first flow control valve 9 is shown in the full open position (maximum flow) in Figure 2 and in the closed position (no flow) in Figure 3 (the second flow control valve 10 is shown in the closed position in Figure 2 and in the full open position in Figure 3). Both flow control valves 9, 10 are shown in a mid-open position in Figure 4.

In the closed position, the first and second valve members iSa, lSb arc received in the centre sections 15 of the first and second valve outlets 14a, 14b and carry an elastomeric seal 20a, 205 that engage valve seats provided by the centre section 15 of the first and second valve outlets 14a, 14b to seal the valve outlets 14a, 14b preventing flow of water from the inlet chamber 13 to the mixing chamber 11. The elastonieric seal could be an 0-ring carried by each valve member 1 Sa, 1 Sb or could be a resilient portion over moulded onto the outwardly facing surface of the valve member.

In the full open position, the first valve member ISa is located within the inlet chamber 13 upstream of the associated valve outlet 1 4a and the second valve member ISb is located outside the inlet chamber 13 downstream of the associated valve seat lSb in the mixing chamber waterway. The first and second valve outlets 14a, 14b are configured such that they present substantially the same area to the water flow.

The first fluid inlet 4 opens to the inlet chamber 13 between the first and second valve outlets Ma, Mb. When opening the first flow control valve from the closed position, the force exerted by the water acts to resist opening movement of the first valve member ISa and to assist opening movement of the second valve member 1 Sb. When closing the first flow control valve from an open position, the force exerted by the water acts to resist closing movement of the second valve member lSb and to assist closing movement of the first valve member 1 Sa.

By configuring the valve outlets 14a, 14b to present substantially the same area to the water flow and arranging the valve members 1 Sa, 1 Sb so that water acts on the valve members I Sa, I Sb in opposite directions and with substantially the same force, the valve member assembly 12 of the first flow control valve 9 is essentially balanced (as previously discussed). As a result, there is substantially no net force on the valve member assembly 12 due to force exerted by the water pressure when opening and closing the first flow control valve 9.

A first end of the spool 19 is received within a blind guide bore 21 formed in the housing 2. A second, opposed end of the spool 19 extends through an opening in the housing 2 and is connected to an actuator 22. The actuator 22 is connected to the housing 2. The actuator 22 is adapted to control the linear position of the spool 19 and thus the position of the first and second valve members ISa, ISb with respect to the valve outlets 1 4a, I 4b.

The actuator 22 comprises a stepper motor arranged to move the spooi 19 linearly in an axial direction. Any suitable actuator for controlling linear motion of the spool niay be employed in place of the stepper motor including, but not limited to, linear actuators. The actuator 22 is connected to the spool 19 by a spool connector portion 23 coupled to the second end of the spool 19 that extends through an opening in the housing 2. An elastorneric seal 24 engages the second end of the spool 19 within the opening to prevent leakage of water from the mixing chamber 11. The seal 24 could be an 0-ring located in a groove in the housing 2.

The mixer valve 1 may include a controller (not shown) which provides control signals to the actuators 22, 22' of the first and second flow control valves 9, 10. The controller may also include a temperature sensor and/or flow rate sensor to measure the temperature and/or flow rate of the water leaving the fluid outlet 8 or at any other relevant point in the mixer valve or external thereto. The signals from the sensor(s) may be used to control the actuator 22, 22' of each flow control valve 9, 10 to control the temperature and/or flow rate of the water leaving the outlet 8. For example the signals may be used to maintain a desired temperature and/or flow rate or to provide feedback to the controller so that the water leaving the outlet 8 corresponds to desired settings despite changes in the water prcssure and temperature at the first fluid inlet 4 and/or second fluid inlet 6. The controller may include an interface to receive settings input by a user. Wired or wireless communication may be provided between the controller, sensor(s) and interface.

Various methods of operating the actuator 22, 22' of each flow control valve 9, 10 to control the temperature and/or flow rate of the water leaving the outlet 8 are now discussed. These are examples only of possible methods of operation and are not intended to be exhaustive of all possible ways in which the mixer valve 1 may be used to provide a source of outlet water having a desired temperature and/or flow rate.

Control to output cold water or hot water.

With the mixcr valve 1 in thc closed position, the first actuator 22 and second actuator 22' position their respective spools 19 and 19' such that the valve members 1 8a, I 85 and I 8a', I 85' of the first and second flow control valves 9, 10 are sealed against their respective valve seats 15 and 15' to prevent flow of water to the outlet 8.

When only cold water is required by the user, the actuator 22 of the first flow control valve 9 is operated to open the first flow control valve 9 and the flow rate of cold water delivered to the outlet S is controlled by adjusting the position of the valve members iSa, 18b relative to the outlets 14a, 14b. The second flow control valve remains closed.

When only hot water is required by the user, the actuator 22' of the second flow control valve 10 is operated to open the second flow control valve 10 and the flow rate of hot water delivered to the outlet S is controlled by adjusting the position of the valve members I Sa', I Sb' relative to tile outlets I 4a', I 4b'. The first flow control valve 9 remains closed.

Control to output blended cold water and hot water With the mixer valve I in the closed position, the first actuator 22 and second actuator 22' position their respective spools 19 and 19' such that the valve members iSa, iSb and iSa', iSb' of the first and sccond flow control valves 9, 10 are sealed against their respective valve seats 15 and iS' to prevent flow of water to the outlet 8.

When water having a temperature between full cold and full hot is rcquired by the user, the actuators 22, 22' of both flow control valves 9, 10 are operated to open both flow control valves 9, 10 together to deliver a mixture of hot and cold water to the outlet 8. The temperature and/or flow rate of the mixed water can, as an example, be adjusted as follows: Adjust flow control valves independently to adjust tcmperaturc and flow rate With both flow control valves 9, 10 open, the actuator 22 is operated to move the valve member assembly 12 of the first flow control valve 9 to open further the first flow control valve 9 and the actuator 22' is kept stationary. The flow of cold water increases and the flow of hot water remains the same resulting in an increase in flow rate and a decrease in temperature of the outlet water.

With both flow control valves 9, 10 open, the actuator 22 is operated to move the valve member assembly 12 of the first flow control valve 9 towards the closed position and the sccond actuator 22' is kept stationary. The flow of cold water reduces and the flow of hot water remains the same resulting in a decrease in flow rate and an increase in tcmperature of the outlet water.

With both flow control valves 9, 10 open, the actuator 22 is kept stationary and the actuator 22 is operated to move the valve menTher assembly 12 of the second flow control valve 10 to open further the flow control valve 10. The flow of cold water remains the same and the tiow of hot water increases resulting in an increase in flow rate and an increase in temperature of the outlet watcr.

With both flow control valves 9, 10 open, the actuator 22 is kept stationary and the actuator 22 is operated to move the valve mcmber assembly 12 of the second flow control valve 10 towards the closed position. The flow of cold water remains the same and the flow of hot water reduces resulting in a decrease in flow rate and a decrease in temperature of the outlet water.

Adjust flow control valves together to change flow rate and maintain temperature With both flow control valves 9, 10 open, the temperature of the outlet water can be kept substantially constant while changing the flow rate by operating the first and second actuators 22, 22' together to move the valve member assemblies 12, 12 of both flow control valves 9, 10 in the same direction by the same amount so that the ratio of cold water to hot water delivered to the mixing chamber 11 remains substantially constant thus maintaining a constant temperature of the outlet water with a change in flow rate of the outlet water.

Thus, with both flow control valves 9, 10 open, if both valve member assemblies 12, 12' are moved to open further the flow control valves 9, 10 the flow rate will increase, and if both valve member assemblies 12, 12' are moved towards the closed position the flow rate will decrease without changing the temperature of the outlet water.

Adjust flow control valves together to change temperature and maintain flow rate With both flow control valves 9, 10 open, the flow rate can be kept substantially constant while changing the temperature by operating the first and second actuators 22, 22 together to move the valve member assemblies 12, 12 of both flow control valves 9, 10 in opposite directions by the same amount so that the ratio of cold water to hot water delivered to the mixing chamber 11 changes but the total volume of water remains the same thus maintaining a constant flow rate with a change in temperature of the outlet water.

Thus, with both flow control valves 9, 10 open, if thc valve membcr assembly 12 of the first flow control valve 9 is movcd to open further the first flow control valve 9 while simultaneously the valve member assembly 12' of the second flow control valve 10 is moved towards the closed position, the flow rate will remain the same but the tcmperature of the outlet water will decrease.

Similarly, with both flow control valves 9, 10 open, if the valve member assembly 12' of the second flow control valve 10 is moved to open further the second flow control valve 10 while simultaneously the valve member assembly 12 of the first flow control valve 9 is moved towards the closed position, the flow rate will remain the same but the temperature of the outlet water will increase.

As will be apparent from the description of the exemplary embodiment of mixer valve I shown in Figures 1 to 4, the configuration of the valve member assemblies 12, 12' of the flow control valves controlling the flow of cold water and hot water to the mixing chamber is such that the valve member assemblies 12, 12' are essentially "force balanced" with respect to the fluid flow. In other words, substantially no net force is exerted on the valve member assemblies 12, 12' by the fluid flow and the actuating force to move the valve member assemblies 12, 12' for operating the flow control valves 9, 10 when controlling the mixer valve 1 is substantially independent of fluid flow.

As a result, the actuating force can be reduced compared to valves where there is a significant imbalance of the forces due to fluid flow. Thus, the actuating force to move the valve member assemblies 12, 12' only has to overcome factors such as friction betwccn the valve seats 15 and the seals 20a, 20b, 20a', 2Gb' on the valve members I 8a, I 85, 1 8a', 18b' and between the spools 19, 19' and the bores 21, 21' and between the spool connector portions 23, 23' and the seals 24, 24'.

By way of example only, in many water supply systems and installations in the United Kingdom the water pressure is in the range 1 to 10 bar and is typically around 3 bar.

If a single valve member is used to control flow through an opening, there is a force imbalance across the valve member due to fluid tiow which has to be overcome by the actuating force in addition to any other factors such as friction. For an opening have a diameter of 9mm this force imbalance is approximately 60 Newtons at a water pressure of 10 bar and approximately 18 Newtons at a water pressure of 3 bar.

By replacing a single opening with a diameter of 9mm with two openings each having a diameter of 6mm we can achieve similar flow rates to that provided by the single opening of larger diameter and, by balancing the effect of fluid flow on the valve members, we can reduce the size (power) of the stepper motors required to move the valve members as the stepper motors no longer have to overcome the force imbalance that exists when using a single valve member.

Thus by employing force balanced valve assemblies, not only can the size of the flow control openings be reduced but the size of the stepper motors to drive the valve assemblies can also be reduced. This in turn also enables the overall size of the mixer valve 1 to be reduced.

Again by way of example, using flow control openings having a diameter of 6mm we can achieve a reduction in size of the mixer valve whereby the housing 2 may have dimensions of 65mm x 30mm x 15mm. By way of comparison prior art mixer valves as shown in Figures 12 and 13 typically have dimensions of around 1 80mm x 130mm x 85mm while prior art electronic mixer valves as shown in Figures 14 and 15 that control temperature only and require separate control of flow rate typically have dimensions of around 230mm x 210mm x 55mm.

By reducing the size of the mixer valve 1, the size of the waterways within the mixer valve I and thus the volume of water present in the mixer valve I and the available surface area in contact with the water for bio-film to form and bacteria to grow can be reduced. Furthermore, by reducing the size of the mixer valve, it may be possible to manufacture the mixer valve, especially parts of the housing 2 forming the waterways and the flow control valves 9, 10 within the waterways, from metal rather than plastics. In particular, parts that come into contact with the water within the mixer valve can be made of brass. Brass contains copper that kills present bacteria in the water thereby reducing and possibly eliminating the formation of bio-films on the surface of the waterways and flow control valves 9, 10.

A further benefit of reducing the size of the waterways within the valve is that the occurrence of trapped areas where water may collect and allow bacteria to grow and/or form bio-films on surfaces within the valve may be reduced. Also the waterways may be configured to promote turbulent flow and high flow velocity through the valve.

This is not only desirable for mixing the hot and cold flows for accurate sensing of the temperature of the outlet water but also assists in preventing formation of bio-films on the exposed surfaces of the waterways within the valve and may even assist in removing any bio-films that are formed, for example as may occur when the valve is not in use, i.e. when there is no flow of water through the valve, and bacteria present in the water remaining in the valve from the previous use of the valve may grow and attach to the exposed surfaces.

To further reduce the health risk from bacteria present in the water, it may be desirable to carry out a disinfection routine at regular intervals to kill and remove (or reduce to acceptable levels) any bacteria and bio-film within the valve. Such disinfection routine may involve fully opening the flow control valve 10 connected to the supply of hot water and passing water at an elevated temperature through the valve 1 for sufficient time to kill and remove ally bacteria and bio-film within the valve. Typically this may involve passing water having a temperature of at least 65°C through the valve for at least 10 minutes although this is by no way limiting and different routines with different water temperatures and/or duration may be employed.

Other disinfection routines may be employed alongside or in place of thermal disinfection with hot water. For example, Figures 5 and 6 show a modification to the mixer valve 1 of Figures 1 to 4 to include an electrical heater 25 and like reference numerals are used to indicate corresponding parts.

The water inlets 4, 6 arc provided on one face 26 of the body 2 of the housing and an electrical heater 25 is located in a bore 27 within the body of the housing 2 on the opposite face 28 and is surrounded by a thermally conductive potting compound 29 for transferring heat from the heater 25 to the metal body of the housing 2. The usc of electrical heating for the disinfection routine is suitable as the valve 1 already has an electrical supply for operating the actuators.

The heater 25 may be employed in a thermal disinfection cycle to heat the metal parts of the housing 2 and the flow control valves 9, 10 within the housing 2 (one only shown in Figure 6) that contact the water to an elevated temperature sufficient to kill any bacteria present in the water and/or any bio-film formed on the exposed surfaces of the waterways within the valve. By reducing the size of the valve 1, the thermal mass of the metal parts to be heated may be significantly reduced and a low power electrical heater (approximately 10 watt) may be sufficient to heat the metal parts of the housing 2 and flow control valves 9, 10 to an elevated temperature of 70°C to 80°C. for 5 minutes which may be sufficient for this purpose.

An advantage of this method compared to the thermal disinfection with hot water is that all of the metal parts of the housing and the flow control valves 9, 10 arc heated whereas thermal disinfection with hot water may not be effective in those areas that do not come into contact with the hot water supply. A temperature sensor (not shown) such as a thermistor may be provided to monitor the temperature during the disinfection cycle and control the power input to the electrical heater 25 to control the disinfection temperature and prevent overheating the housing 2 and flow control valves 9, 10 which may damage any parts not made of metal such as the seals.

The housing 2 is preferably insulated so that exposed external surfaces are not heated to a high temperature. In this way, the risk of a user touching any part of the valve that has been heated to the elevated temperature used for the disinfection routine may be reduced and possibly eliminated. Such insulation also improves the efficiency of the thermal disinfection cycle by reducing heat loss to the environment and may allow use of a lower power heating clement.

The valve I may be disabled during the disinfection cycle to prevent discharge of water from the outlet while the metal parts of housing 2 and flow control valves 9, 10 arc being heated during the disinfection cycle and/or while they are cooling down after the disinfection cycle. Thus, operation of the mixer valve I may be prevented during the disinfection cycle and for an interval of time after the disinfection cycle is completed to allow the valve 1 and any water in the valve to cool down and prevent very hot water being discharged when the valve is next used. In this way the risk of a user being scalded by very hot water may be reduced and possibly eliminated.

The controller may respond to initiation of the disinfection cycle to prevent operation of the valve until it is safe. Thus, the temperature sensor for controlling the electrical heater (or a separate sensor) may provide feedback of temperature to the controller so that the valve is not operable until the metal parts of the housing 2 and flow control valves have cooled down to a safe temperature. Also the sensor monitoring the outlet water temperature (or a separate sensor) may provide feedback of temperature to the controller so that the valve is not operable until the water in the valve has cooled down to a safe temperature. Any suitable form of electrical heating may be employed.

Referring now to Figure 7, a mixer valve I is shown with a controller 55 for controlling operation of the valve 1. The mixer valve 1 is similar to previous cmbodiments and like reference numerals are used to indicate similar parts. The controller 55 provides control signals to control actuation of the actuators 22, 22 of the first and second flow control valves (not visible) to adjust the positions of the valve member assemblies (not visible) to control the flow rate and temperature of the outlet water delivered to the outlet as described previously.

The controller 55 may be an electronic controller with control circuitry that may include a microprocessor or similar electronic controller mounted on a control panel 56 such as a printed circuit board. The controller 55 may include an interface (not visible) to allow a user to select a required flow rate and/or temperature of the outlet water. The interface may be a physical interface including one or more rotatable knobs or linear sliders or push buttons for selecting flow rate and/or temperature. Alternatively, the interface may be a virtual interface that uses touch screen technology or the likc. The interface may include a display for providing a visual indication of the flow rate and/or temperature. The display niay be a digital display of nunierical values and/or visual display such as an array of lights. The controller 55 receives the user's setting from the interface and sends control signals to the actuators 22, 22' to operate the flow control valves as describcd in connection %vith previous embodiments to achieve the selected temperature and flow rate of the outlet water.

The controller 55 may be programmable and may include a memory for storing different settings of temperature and/or flow rate of the outlet water that may be set via the interface and selected by a user via the interface. The controller 55 may allow selection of a disinfection cycle and may collect and store details of the disinfection cycle. For example, in plumbing fixtures and fittings and water supply systems and installations that require regular disinfection, the memory may record when the disinfection cycle is carried out and the temperature of the outlet water and the duration of the disinfection cycle which may be used to check that the disinfection routine has been carried out and has been successful.

The interface may be incorporated into the plumbing fixture or fitting. Alternatively or additionally, the interface may be incorporated into a remote control that communicates with the controller 55 via a wired or wireless connection. For example, where the mixer valve 1 is incorporated in a plumbing fixture or fitting that, in use, is out of reach of the user, the controller 55 may receive control signals via a wired or wireless link from an interface mounted remotely from the mixer valve I. In one form of wireless link, the interface may include a wireless transmitter and the controller may include a wireless receiver to receive control signals, for example radio frequency signals, representative of a user's selected input via the interface.

By reducing the size of the mixer valve 1, the mixer valve 1 may be configured for supplying water for a range of different applications including hand washing, showering and bathing. Thus mixer valves for supplying water for hand washing may typically be required to have a flow coefficient (C-value) of 0.5 to 1.0 corresponding to flow rates of 5 to 10 litres per minute at a pressure of I bar, while mixer valves supplying water for showering may typically be required to have a flow coefficient of 1.0 to 3.0 corresponding to flow rates of 10 to 30 litres per minute at a pressure of 1 bar and mixer valves for supplying water for bath filling may typically be required to have a flow coefficient of 3.0 to 5.0 corresponding to flow rates of 30 to 50 litres per minute at I bar.

We have found that using flow control openings have a diameter of 6mm we can achieve a flow coefficient (C-value) of around 2.5 corresponding to a flow rate of 25 litres per minute at I bar when both flow control valves 9, 10 are in the mid-open position (Figure 4). In this way, the mixer valve 1 can meet the flow requirements for hand washing, showering and bath filling.

The flow rates for showering are provided when both flow control valves 9, 10 are opened to the mid-open position (Figure 4) and controlling temperature without changing flow by reducing flow of one supply and increasing flow of the other supply by the same amount or controlling flow without changing temperature by eithcr reducing or increasing flow of both supplies by the same amount. Flow rates for hand washing may be achieved by opening both flow control valves 9, 10 less than the niid-open position (Figure 4) and controlling temperature and/or flow rate as for showering. Higher flow rates for bath filling can be achieved by fully opening both flow control valves 9, 10 and controlling temperature by reducing flow of the hot or cold water as necessary.

These flow rates and dimensions are provided by way of non-limiting cxample and it will be understood that different flow rates and dimensions may be employed where appropriate for the intended application of the mixer valve.

Various control routines may be employed for operating thc mixer valve 1 depending on the application. Routines for showering and bath filling are now described. These are examples only of possible routines and are not intended to be exhaustive of all possible routines which may be used when operating the mixer valve 1.

Routine for showering The valve men-iber assemblies 12, 12 of the first and second flow control valves 9 and 10 are both moved simultaneously and equally to the mid-open position (50% actuator travel) shown in Figure 4 by their respective actuators 22, 22' to provide a nominal flow rate.

To change the flow rate without changing the temperature of the outlet water, both valve member assemblies 12, 12' are simultaneously moved from the mid-open position (Figure 4) in the same direction either towards the closed position to reduce flow rate or towards the open position to increase flow rate while maintaining the ratio of hot and cold water to keep thc temperature of the outlet water constant.

Further changes to increase or decrease flow from any adjusted position without changing the temperature of the outlet water can be made in similar manner.

To change the outlet water temperature without changing the flow rate from the nominal flow (50% of actuators travel position) starting point, the valve assemblies 12, 12 are simultaneously moved in opposite directions to increase one flow whilst simultaneously reducing the other flow by an equal amount. By operating the first and second flow control valves 9, 10 in this way, the ratio of the hot and cold water is changed but the total flow remains the same so that the temperature of the outlet water can be adjusted without substantially affecting the flow rate.

Both temperature and flow rate can be adjusted in use by a combination of movement of the valve member assemblies to change the flow rate and the temperature and/or to maintain a selected flow rate or temperature.

Routine for bath filling The valve mcmbcr assemblies 12, 12' of the first and second flow control valves 9, 10 are both moved to the fully open positions (100% actuator travel) to achieve the maximum flow rate.

Temperature is then controlled by reducing the flow of hot water if the temperature of the outlet water needs to be reduced by moving the valve member assembly 12' of the second flow control valve 10 towards the closed position or by reducing the flow of cold water if the temperature of the outlet water needs to be increased by moving the valve member assembly 12 of the first flow control valve 9 towards the closed position.

Although such adjustn-ient changes the flow rate as well as the temperature of the outlet water, such change is acceptable in the context of bath filling where the user is typically not exposed directly to the flow of water from the outlet as is usually the case when showering where changes to flow and temperature are readily detected and greater control is required, particularly to reduce the risk of scalding by very hot water.

By reducing thc size of the mixer valve 1, it may be possible to employ the mixer valve I in situations where it has not previously been possible to use existing mixer valves. In particular, the small size of the mixer valve 1 as discussed herein opens up the possibility of incorporating the mixer valve into a wide range of plumbing fixtures and fittings that could not incorporate existing mixer valves due to their size and other constraints on the design and installation of such plumbing fixtures and fittings.

The mixer valve I may also be used to replace mixer valves employed in existing plumbing fixtures and fittings. Here the small size of the mixer valve I may allow the size of such existing plumbing fixtures and fillings to be reduced and/or the shape to be altered.

Thus, the mixer valve 1 increases the freedom of designers when designing plumbing fixtures and fittings and water supply systems and installations incorporating such plumbing fixtures and fittings that incorporate the mixer valve 1. Various examples of plumbing fixture and fittings incorporating the mixer valve 1 are now described.

These arc examples only of possible applications of the mixer valve 1 and are not intended to be exhaustive of all possible applications in which the mixer valve I may be incorporated in a plumbing fixture or fitting.

Referring to Figures 8a and 8b, an embodiment of a plumbing fitting 50 comprising a fluid delivery device such as a shower head incorporating a mixer valve 1 is shown.

The mixer valve 1 is similar to previous embodiments and like reference numerals are used to indicate corresponding parts.

The shower head 50 comprises a moveable handset and includes a stem 51 that can be inserted into a shower head dock within a shower enclosure (not shown). The shower head 50 could alternatively be a fixed shower head that is arranged to be fixed to and project from a wall.

The shower head 50 includes a spray head 53 that provides a plurality of outlets for discharge of water in use to provide a variety of different spray patterns. In one arrangement, the spray head 53 has outlets in opposite sides and optionally on one or more side edges. The spray head 53 can rotate within a substantially circular spray head mount 58 about diametrically opposed pivots 59 to select an outlet for use.

According to other exemplary embodiments, other types of spray heads may be used, including those that are configured to provide only a single spray pattern and those that operate differently than the spray head 53 shown in Figures 8a and 8b to provide multiple spray patterns.

The shower head stem 51 receives the mixer valve 1 together with the controller 55.

The stem SI includes two conduits -a cold water supply conduit 54 and a hot water supply conduit (not visible). The cold water conduit 54 connects to the first fluid inlet 4 and the hot water conduit connects to the second fluid inlet (not shown) of the mixer valve 1. The fluid outlet 8 of the mixer valve I is connected to the spray head 53 by an outlet conduit 56. The outlet conduit 56 extends through the spray head mount 58 and enters the spray head 53 through the pivots 59.

The controller 55 provides control signals to the mixer valve I for controlling the flow rate and temperature of the outlet water delivered to the spray head 53 according to the user selection via the interface (not visible). The interface may be arranged on the stem 51 to allow a user to select the flow rate and temperature of the outlet water they wish. The interface may be a physical interface including one or more rotatable knobs or linear sliders or push buttons for selecting flow rate and/or temperature.

Alternatively, the interface may be a virtual interface that uses touch screen technology or the like. The interface may include a display for providing a visual indication of the flow rate and/or temperature. The display may be a digital display of numerical values and/or visual display such as an array of lights.

In other embodiments, the interface may be incorporated into a remote control that communicates with the controller 55 via a wired or wireless link. Thus, if the shower head 50 is of fixed type, then the controller 55 may receive control signals from an interface mounted remotely from the shower head 50.

Referring now to Figures 9a and 9b, an embodiment of a plumbing fitting comprising a fluid delivery device such as a faucet 60 incorporating a mixer valve 1 is shown.

The faucet 60 may bc in the form of a tap and includes a base 61 by which it is secured to a support surface such as a sink or worktop (such as kitchen or bathroom worktop). The faucet 60 includes a perforated plate 63 that provides an outlet for the water for use. The faucet 60 receives the mixer valve 1 together with the controller 55.

The faucet 60 has a stem portion (sometimes referred to as a "spout") and two conduits -a cold water supply conduit 64 and a hot water supply conduit 65. The cold water conduit 64 connects to the first fluid inlet 4 and the hot water supply connects to the second fluid inlet (not visible) of the mixer valve 1. The fluid outlet S of the mixer valve 1 is connected to the plate 63 by an outlet conduit 66.

The controller (not shown) provides control signals to the mixer valve 1 for controlling the flow rate and temperature of the outlet water delivered to the plate 63 according to the user selection via an interface 67 on the base 61 to allow a user to select the flow rate and temperature they wish. The interface 67 includes a touch sensitive pancl 67a for inputting settings and a display 69b which shows the water temperature. It will, be appreciated that the interface 67 can be of any suitable form for receiving user inputs for controlling the mixer valve 1.

Conventional faucets require a valve base that is secured to the support surface and the spout then extends from the valve base to channel the water to where it needs to be dispensed. The present embodiment is advantageous as the mixer valve, due to its ability to be miniaturized (i.e. reduced in size), can be incorporated into the spout without the i-iced for the valve base. Also the rectangular shape of the housing 2 provides the designer with the opportunity to employ different configurations for the stem portion (spout) of the faucet.

Referring now to Figure 10, an embodiment of a plumbing fitting comprising a fluid delivery device such as a fixed shower head 70 incorporating a mixer valve 1 is shown. The mixer valve I is similar to previous embodiments and like reference numerals are used to indicate corresponding parts.

The fixed shower head 70 includes a base 71 by which it is secured to a wall or similar support surface within a shower enclosure (not shown). The shower head 70 includes a perforated plate 72 that provides an outlet for the water iii use. The shower head 70 receives the mixer valve I together with the controller 55. The shower head 70 has two conduits -a cold water supply conduit 73 and a hot water supply conduit 74. The cold water supply conduit 73 is connected to the first fluid inlet (not visible) and the hot water supply conduit 74 is connected to the second fluid inlet (not visible) of the nñxcr valve 1.

The mixer valve is similar to the embodiment shown in Figures 8a and Sb except that the controller 55 is mounted within the shower head 70 differently such that the supply conduits 73 and 74 pass between the mixer valve I and the controller 55. The fluid outlet 8 of the mixer valve I is connected to the plate 72 by an outlet conduit 76.

The controller 55 provides control signals to the mixer valve 1 for controlling the flow rate and temperature of the outlet water delivered to the plate 72 according to the user selection via a remote interface (not shown) allowing a user to select the flow rate and temperature they wish. It will be appreciated that the interface can be of any suitable form such as the interfaces disclosed herein for receiving user inputs for controlling the mixer valve I and the controller 55 may be arranged to receive control signals from the interface by a wired or wireless link for controlling the actuators 22, 22'.

Referring now to Figures ii a, 11 b and lie, an embodiment of a plumbing fitting comprising a shower valve 40 of the bar mixer type that incorporates an embodiment of the mixer valve I described herein is shown.

The shower valve 40 comprises a cold water inlet 41, a hot water inlet 42 and a blended water outlet 43. The outlet is connected to a tiexible shower hose 44 that leads to a shower head (not shown) or the like. The shower valve 40 includes a control panel 45 which controls the mixer valve I. The control panel 45 includes controls 45a for switching the shower on and oft setting the flow rate and the temperature of the outlet water and also a temperature display 45b to display the temperature of the outlet water. The controls 45a niay include an interface such as the interfaces disclosed herein.

In this embodiment, the mixing chamber 11 includes an elongate structure formed by a conduit with the first flow control valve 9 at one end of the conduit and the second flow control valve 10 at the other, opposed end of the conduit. The valve outlet 43 is formed in the conduit in between the first and second flow control valves 9, 10.

The flow control valves 9, 10 are similar to those described above in relation to the embodiment of Figures 1 to 4 and like reference numerals are used to indicate corresponding parts. The first flow control valve 9 is shown in Figure lie and the following description of the first flow control valve 9 also applies to the second flow control valve 10.

In this embodiment, the flow control valve 9 has a valve member assembly 12 with valve members 1 8a, 1 Sb mounted on a spool 19 connected to an actuator 22. The valve members iSa, lSb carry an elastomeric seal 20a, 20b that faces in a longitudinal and radial direction. Rather than being received in the centre section of the valve outlets 14a, 14b in the closed position as in the embodiment of Figures 1 to 4, the valve members 1 Sa, I Sb are arranged to engage end sections of the valve outlets 14a, 14b that provide the valve seats in the closed position shown in Figure lie.

The valve member iSa is disposed within the inlet chamber 13 and engages end section 16 of the valve outlet 14a and the valve member iSb is arranged in the mixing chamber 11 and engages the end section 17 of the valve outlet 14b. The valve inlet chamber 13 receives the water from the inlet 4 and the valve members 1 Sa, 1 Sb are movable under the control of the actuator 22 to open the flow control valve and control the flow of water from the valve chamber 13 into the mixing chamber 11 in similar manner to the embodiment of Figures 1 to 4. The mixing chamber 11 receives water from one or both flow control valves 9, 10 according to the operating routine of the mixer valve 1 as described in connection with Figures 1 to 4 and the water leaves the mixing chamber 11 via outlet 43 for use.

The embodiments described above relate to mixer valves. However, the flow control valves 9, 10 could be used individually to control fluid flow. As an example, the control valve 9 shown in Figure 1 Ic could be employed separately from the flow control valve 10 in any application where it is desired to control the flow rate of a water supply.

In such application, the mixing chamber II of the shower valve 40 shown in Figure 1 lb is replaced with an outlet chamber which directs the flow from the outlets 14a, 14b of the flow control valve 9 to an outlet (not shown) for the intended application. The flow control valve 9 operates to control tiow rate in similar manner to previous embodiments. Similarly the flow control valves 9, 10 of other embodiments may be employed separately to control flow rate.

One application for such a flow control valve could be in an instantaneous water heater of the type in which a supply of water is heated as it passes through a heater tank to provide a source of hot water on demand. In such instantaneous water heaters (sometimes referred to as continuous flow water heaters), for a given power input to the heater tank, the tempcrature of the outlet water is determined by the flow rate of the water through the heater tank and control of flow rate may be used to achieve and maintain a selected outlet water temperature. One application for such water heaters is in an electric shower to supply water to one or more shower outlets such as a handset or fixed shower handset. Other applications of the flow control valve will be apparent to those skilled in the art.

It will be appreciated that while the embodiments of the mixer valve and the flow control valve described herein are shown as being incorporated into plumbing fittings, they have wider application. For example, due to the valve's ability to be miniaturised (i.e. reduced in size) while maintaining a high flow rate for its size it may have advantageous uses in process control valves, pneumatic and hydraulic systems, medical equipment or in automotive components or other components where control of flow rate of a fluid and/or mixing of two fluids having different characteristics is required. Thus, mixing fluids may not be limited to fluids having different temperatures.

As utilizcd herein, the terms "approximately," "about," "around," "substantially," and similar tenns are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who revicw this disclosure that these terms arc intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these tenns should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.

It should be noted that the term "exemplary" as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

The terms "coupled,' connected," and the like as used herein mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.

References herein to the positions of elements (e.g., "top," "bottom," "above," "below," etc.) are merely used to describe the orientation of various elements in the Figures. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be

encompassed by the present disclosure.

It is important to note that the construction and arrangement of the mixer valves and related assemblies as shown in the various exemplary embodiments is illustrative only. Although only a few embodinients have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method slops may be varied or re-sequenced according to alternative embodiments.

Features of any of the embodiments may be employed separately or in combination with any other feature(s) of the same or different embodiments and the disclosure extends to and includes all such arrangements whether or not described herein.

Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the inventions described herein.

Claims

CLAIMS1. A mixer valve comprising a first fluid inlet adapted to receive a first fluid, a second fluid inlet adapted to receive a second fluid, a fluid outlet adapted to output the first fluid or tile second fluid or a mixture thereof, and a first flow control valve for controlling the flow of fluid from the first fluid inlet and a second flow control valvc for controlling thc flow of fluid from the sccond fluid inlct, cach of thc first and second flow control valves including a valve member assembly to control the fluid flow through the respective flow control valve, the valve member assembly and the fluid inlet of each of the first and second flow control valves adapted and arranged such that, when in use, fluid flowing through the first flow control valve exerts substantially no net force on the valve member assembly of the first flow control valve and fluid flowing through the second flow control valve exerts substantially no net force on the valve member assembly of the second flow control valve. is
2. A mixer valve according to claim I, in which each flow control valve comprises a valve inlet for receiving fluid from one of the first or second fluid inlets, thc valve mcmbcr asscmbly including a first valve member adaptcd to engage with a first valve seat in a closed position of the flow control valve and a second valve member adapted to engage with a second, separate, valve seat in the closed position of the flow control valve, wherein the first valve member is arranged to be urged closed by fluid entering through the valve inlet and the second valve member is arranged to be urged open by fluid entering through the valve inlet.
3. A mixer valve according to claim 2, in which cach valve inlet is located between the first valve member and the second valve member of each of the first and second flow control valves.
4. A mixer valve according to claim 2 or claim 3, in which each valve inlet opens into a chamber defined by a chamber wall having a first valve outlet and a second valve outlet formed therein.
5. A mixer valve according to claim 4, in which the first valve member is associated with the first valve outlet and the second valve member is associated with Ihc sccond valve outlct.
6. A mixer valve according to claim 4 or claim 5, in which the mixer valve includes a mixing chamber that includes the fluid outlet with the mixing chamber arranged to receive tluid from the first and second valve outlets of the flow control valves.
7. A mixer valve according to claim 6, in which the first and second outlets are of similar size.
8. A mixer valve according to any of claims 4 to 7, in which the first and second outlets are axially aligned.
9. A mixer valve according to claim 8, in which the first and second valve members of each flow control valve are connected to a spool coupled to an actuator which controls the position of the valve members relative to their respective valve seats.
10. A mixer valve according to claim 9, in which the actuator comprises an electrically powered motor.
11. A mixer valve according to claim 10, in which the motor comprises a stepper motor.
12. A mixer valve according to any of claims 9 to 11, in which the valve seats are located within the valve outlets.
13. A mixer valve according to claim 12, in which the valve seats include a cylindrical bore portion of the valve outlets in which the valve members are slidably received in the closed position.
14. A mixer valve according to any of claims 9 to 11, in which the valve seats are located at one end of the valve outlets.
15. A mixer valve according to claim 14, in which the valve seats include an end face of the valve oullets against which the valve members seat in the closed position.
16. A mixer valve according to any of claims 4 to 15, in which the first valve member is received in the valve inlet chamber in an open position of the flow control valve and the second valve member is received in the mixing chamber in the open position of the flow control valve.
17. A mixer valve according to any preceding claim, in which the mixer valve includes a housing that houses the first and second flow control valves and includes apertures that form the first fluid inlet, the second fluid inlet and the fluid outlet.
18. A mixer valve according to claim 17, in which the housing is made of metal or alloy and includes an electrically powered heating device for thermally disinfecting the mixer valve.
19. A mixer valve according to claim 18, in which the mixing valve is disabled during a thermal disinfection cycle to prevent discharge of water.
20. A mixer valve according to claim 19, in which the thermal disinfection cycle includes a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and a cool down cycle to allow the housing and water contained in the valve to cool down after the heating cycle.
21. A mixer valve according to any preceding claim, in which the first and second flow control valves are connected in use to supplies of hot and cold water and are controlled in response to water temperature and/or flow rate.
22. A mixer valve according to claim 21, in which a sensor device is arranged to monitor the temperature and/or flow rate of the outlet water and the tiow control valves arc controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.
23. A mixer valve according to claim 21, in which a sensor device is arranged to monitor the temperature of the supplies of hot and cold water and/or flow rate of the outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.
24. A mixer valve comprising a first inlet for receiving a first fluid, a second inlet for receiving a second fluid, and a mixing chamber having a fluid outlet for outputting the first fluid or the second fluid or a mixture thereof, the mixer valve including a first flow control valve for controlling the flow of the first fluid into the mixing chamber and a second flow control valve, separate from the first flow control valve, for controlling the flow of the second fluid into the mixing chamber, wherein at least the first or second flow control valve includes at least two, separate outlets into the mixing chamber.
25. A mixer valve according to claim 24, in which both the first flow control valve and second flow control valve each include at least two, separate outlets into the mixing chamber.
26. A mixer valve according to claim 24 or 25, in which each flow control valve is defined by an elongate valve inlet chamber having a valve inlet and two separate valve outlets formed at substantially opposite ends of the valve inlet chamber.
27. A mixer valve according to claim 26, in which the valve inlet is located between the valve outlets.
28. A mixer valve according to claim 26 or claim 27, in which the first valve member is received in the valve inlet chamber in an open position of the flow control valve and the second valve member is received in the mixing chamber in the open position of the flow control valve.
29. A mixer valve according to any of claims 26 to 28, in which each flow control valve includes a valve member assembly including a first valve member adapted to engage with a first valve seat associated with a first of the two valve outlets in a closed position of the flow control valve and a second valve member adapted to engage with a second, separate, valve seat associated with a second of the two valve outlets in the closed position of the flow control valve.
30. A mixer valve according to claim 29, in which the first valve member is arranged to be urged closed by fluid entering the valve inlet chamber through the valve inlet and the second valve member is arranged to be urged open by fluid entering the valve inlet chamber through the valve inlet.
31. A mixer valve according to claim 29 or claim 30, in which the first and second valve members of each flow control valve are connected to a spool coupled to an actuator which controls the position of the valve members relative to their respective valve seats.
32. A mixer valve according to claim 31, in which the actuator comprises an electrically powered motor.
33. A mixer valve according to claim 32, in which the motor comprises a stepper motor.
34. A mixer valve according to any of claims 29 to 33, in which the valve member assembly is balanced such that fluid flowing through the flow control valve exerts substantially no net force on the valve member assembly.
35. A mixer valve according to any of claims 29 to 34, in which the first and second valve outlets are of similar size.
36. A mixer valve according to any of claims 29 to 35, in which the first and second valve outlets are axially aligned.
37. A mixer valve according to any of claims 29 to 36, in which the valve seats are located within the valve outlets.
3. A mixer valve according to claim 37, in which the valve seals include a cylindrical bore portion of the valve outlets in which the valve members are slidably received in the closed position.
39. A mixer valve according to any of claims 29 to 36, in which the valve seats are located at one end of the valve outlets.
40. A mixer valve according to claim 39, in which the valve seats include an end facc of the valve outlets against which the valve members seat in the closed position.
41. A mixer valve according to any of claims 24 to 40, in which the mixer valve includes a housing that houses the first and second flow control valves and includes apertures that form the first fluid inlet, the second fluid inlet and the fluid outlet.
42. A mixer valve according to claim 41, in which the housing is made of metal or alloy and includes an electrically powered heating device for thermally disinfecting the mixer valve.
43. A mixer valve according to claim 42, in which the mixing valve is disabled during a thermal disinfection cycle to prevent discharge of water.
44. A mixer valve according to claim 43, in which the thermal disinfection cycle includes a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and a cool down cycle to allow the housing and water contained in the valve to cool down after the heating cycle.
45. A niixer valve according to any of claims 24 to 44 in which the first and second flow control valves are connected in use to supplies of hot and cold water and are controlled in response to water temperature and/or flow rate.
46. A mixer valve according to claim 45, in which a sensor device is arranged to monitor the temperature and/or flow rate of the outlet water and thc flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.
47. A mixer valve according to claim 45, in which a sensor device is arranged to monitor the temperature of the supplies of hot and cold water and/or flow rate of the outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.
48. A plumbing fitting constructed and arranged to receive the mixer valve of any one of claims 1 to 47.
49. A plumbing fitting according to claim 48, in which thc fitting compriscs a fluid delivery device.
50. A plumbing fitting according to claim 48 or claim 49, in which the fitting comprises shower head.
51. A plumbing fitting according to claim 48 or claim 49, in which thc fitting comprises a faucet.
52. A plumbing fitting according to claim 51, in which thc faucct is selected from a bath tap, a sink tap and a basin tap.
53. A water supply system including a mixer valve according to any of claims 1 to 47.
54. A water supply system including a plumbing fitting according to any of claims 48 to 52.
55. A shower head adapted to receive a first fluid conduit and a second fluid flow conduit, wherein the shower head includes a mixer valve adapted to receive a first fluid from the first fluid conduit and a second fluid from the second fluid conduit and output the first fluid or the second fluid or a blend the first and second fluids to a shower head outlct.
56. A shower head according to claim 55, in which the mixer valve comprises the mixer valve of any one of claims 1 to 47.
57. A shower head according to claim 55 or claim 56, in which the shower head includes a stem portion to receive the first and second fluid conduits and at least one outlet to discharge fluid received from the mixer valve.
58. A shower head according to claim 57, in which the stem portion includes body having a duct therein for a fixed shower head or a handle having a duct therein for a moveable shower head.
59. A shower head according to claim 5, in which the duct carries the first and second fluid flow conduits.
60. A shower head according to any of claims 57 to 59, in which the mixer valve is received in the stem portion of the shower head.
61. A shower head according to any of claims 57 to 60, in which a spray head is provided having a single outlet provided with a spray plate having an array of holes for discharging water.
62. A shower head according to claim 61, in which the array of holes can be configured to discharge water in any selected one of a plurality of spray patterns.
63. A shower head according to any of claims 57 to 60, in which a spray head is provided having a plurality of outlets and the spray head is adjustable to select any one of the outlets or a combination of outlets for discharging water.
64. A water supply system provided with a shower head according to any of claims 55 to 63.
65. A fluid delivery device adapted to receive a first fluid conduit and a second fluid flow conduit, wherein the fluid delivery device includes a mixer valve adapted to receive a first fluid from the first fluid conduit and a second fluid from the second fluid conduit and output the first fluid or thc second fluid or a blend the first and second fluids to an outlet of the fluid delivery device
66. A fluid dclivery device according to claim 65, in which the mixer valve comprises the mixer valve of any one of claims 1 to 47.
67. A fluid delivery device according to claim 65 or claim 66, in which the fluid delivery device includes a body portion to receive the first and second conduits and an outlet to discharge fluid received from the mixer valve.
68. A fluid delivery device according to claim 67, in which thc fluid delivery device includes a faucet.
69. A tluid delivery device according to claim 68, in which the faucet eompriscs a tap selected from the group comprising a bath tap, a sink tap and a basin tap.
70. A fluid delivery device according to any of claims 67 to 69, in which the body portion includes a base portion and a stein portion.
71. A fluid delivery device according to claim 70, in which the stem portion is movable relative to the base portion and is provided with the outlet for discharging water.
72. A tap spout according to claim 71, in which the stem portion is arranged to pivot about the base portion.
73. A water supply system provided with a fluid delivery device according to any of claims 65 to 72.
74. A flow control valve including a valve inlet adapted to receive a fluid, a valve outlet adapted to output the fluid, the flow control valve including a valve member assembly to control the fluid flow through the flow control valve, wherein the valve member assembly and the valve inlet are configured such that, when in use, fluid flowing through the tiow control valve exerts substantially no net force on the valve member assembly.
75. A flow control valve according to claim 74, in which the valve member assembly comprises a first valve member adapted to engage with a first valve seat in a closed position of the flow control valve and a second valve member adapted to engage with a second, separate, valve seat in the closed position of the flow control valve, wherein the first valve member is arranged to be urged closed by fluid entering through the valve inlet and the second valve member is arranged to be urged open by fluid entering through the valve inlet.
76. A tiow control valve according to claim 75, in which thc valve inlet is located between the first valve member and the second valve member.
77. A flow control valve according to claim 76, in which the valve inlet opens into a valve inlet chamber defincd by a chamber wall having a first valve outlet and a second valve outlet formed therein.
78. A flow control valve according to claim 77, in which the first valve seat is associated with the first valve outlet and the second valve seat is associated with the second valve outlet.
79. A flow control valve according to claim 77 or claim 78, in which the first and second valve outlets are of similar size.
80. A flow control valve according to any of claims 77 to 79, in which the first and second valve outlets are axially aligned.
81. A flow control valve according to claim 80, in which the first and second valve members connected to a spool coupled to an actuator which controls the position of the valve members relative to their respective valve seats.
82. A flow control valve according to claim 81, in which the actuator comprises an electrically powered motor.
83. A flow control valve according to claim 82, in which the motor comprises a stepper motor.
84. A flow control valve according to any of claims 81 to 83, in which the valve seats are located within the valve outlets.
85. A tiow control valve according to claim 84, in which the valve seats include a cylindrical bore portion of the valve outlets in which the valve members are slidably received in the closed position.
86. A flow control valve according to any of claims 81 to 83, in which the valve seats are located at one end of the valve outlets.
87. A flow valve according to claim 86, in which the valve seats include an end face of the valve outlets against which the valve members seat in the closed position.
88. A flow control valve according to any of claims 77 to 87, in which the flow control valve includes an outlet chamber that includes the fluid outlet and is arranged to receive fluid from the first and second valve outlets.
89. A tiow control valve according to claim 88, in which the first valve member is received in the valve inlet chamber in an open position of the flow control valve and the second valve member is received in the outlet chamber in the open position of the flow control valve.
90. A flow valve according to any of claims 74 to 89, in which the valve includes a housing that houses the flow control valve and includes apertures that form the fluid inlet and the fluid outlet.
91. A flow control valve according to claim 90, in which the housing is made of metal or alloy and includes an electrically powered heating device for thermally disinfecting the valve.
92. A flow control valve according to claim 91, in which the valve is disabled during a thermal disinfection cycle to prevent discharge of water.
93. A flow valve according to claim 92, in which the thermal disinfection cycle includes a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and a cool down cycle to allow the housing and water contained in the valve to cool down after the heating cycle.
94. A flow control valve according to any of claims 74 to 93, in which the valve is connected to a supply of water and controlled in response to water flow rate.
95. A flow control valve according to claim 94, in which a sensor dcvicc is arranged to monitor flow rate of the outlet water and the valve is controlled to achieve and maintain a user selected flow rate.
96. A plumbing fitting provided with a flow control valve according to any of claims 74 to 95.
97. A water supply system provided with a flow control valve according to any of claims 74 to 95.9. A tiow control valve including a valve inlet adapted to receive a fluid and a valve outlet chamber having a fluid outlet for outputting the fluid, the flow control valve controlling the flow of fluid into the outlet chamber, wherein the flow control valve includes at least two, separate valve outlets into the outlet chamber.99. A flow control valve according to claim 98, in which the valve inlet opens into an elongate valve inlet chamber having two separate valve outlets formed at substantially opposite ends of the valve chamber with the valve inlet located between the valve outlets.100. A flow control valve according to claim 99, in which the flow control valve includes a valve member assembly to control the flow through the control valve that is balanced such that fluid flowing through the control valve exerts substantially no net force on the valve member assembly.101. A flow control valve according to claim 99 or claim 100, in which the valve member assembly comprises a first valve member adapted to engage with a first valve seat associated with a first of the two valve outlets in a closed position of the flow control valve and a second valve member adapted to engage with a second, separate, valve seat associated with a second of the two valve outlets in the closed position of the flow control valve.102. A flow control valve according to claim 101, in which the first valve member is arranged to be urged closed by fluid entering the inlet chamber through the inlet and the second valve member is arranged to be urged open by fluid entering the inlet chamber through the inlet.103. A flow control valve according to any of claims 99 to 102, in which the first and second valve outlets are of similar size.104. A flow control valve according to any of claims 99 to 103, in which the first and second valve outlets are axially aligned.105. A flow control valve according to claim 104, in which the first and second valve members connected to a spool coupled to an actuator which controls the position of the valve members relative to their respective valve seats.106. A flow control valve according to claim 105, in which the actuator comprises an electrically powered motor.107. A flow control valve according to claim 106, in which the motor comprises a stepper motor.108. A flow control valve according to any of claims 105 to 107, in which the valve seats are located within the valve outlets.109. A flow control valve according to claim 108, in which the valve seats include a cylindrical bore portion of the valve outlets in which the valve members arc slidably received in the closed position.110. A flow control valve according to any of claims 105 to 107, in which the valve seats are located at one end of the valve outlets.111. A flow valve according to claim 110, in which the valve seats include an end face of the valve outlets against which the valve members seat in the closed position.112. A flow control valve according to any of clainis 99 to iii, in which the first valve member is received in the valve inlet chamber in an open position of the flow control valve and the second valve member is received in the outlet chamber in the open position of thc flow control valve.113. A how valve according to any of claims 98 to 112 in which the valve includes a housing that houses the flow control valve and includes apertures that form the fluid inlet and the fluid outlet.114. A flow control valve according to claim 113, in which the housing is made of metal or alloy and includes an electrically powered heating device for thennally disinfeeting the valve.115. A flow control valve according to claim 114, in which the valve is disabled (luring a thennal disinfection cycle to prevent discharge of water.116. A flow control valve according to claim 115, in which the thermal disinfcction cycle includes a heating cycle to heat the housing to a temperature sufficient to disinfect waterways within the housing and a cool down cycle to allow the housing and water contained in the valve to cool down after the heating cycle.117. A flow control valve according to any of claims 98 to 116, in which the valve is connected to a supply of water and controlled in response to water flow rate.118. A flow control valve according to claim 117, in which a sensor device is arranged to monitor flow rate of the outlet water and the valve is controlled to achieve and maintain a user selected flow rate.119. A plumbing fitting provided with a flow control valve according to any of claims 98 to 118.120. A water supply system provided with a flow control valve according to any of claims 98 to 118.121. A method of controlling flow rate and/or temperature of outlet water from a mixer valve having first and second flow control valves, the method including connecting the first Ilow control valve to a first water supply, connecting the second flow control valve to a second water supply, wherein the first and second water supplies have different temperatures, configuring the first and second flow control valves so that an operating forcc to actuate the flow control valves is substantially independent of water flow, and controlling the first and second flow control valves separately or in combination and outputting a flow of the first water supply or the second water supply or a blend of the first and second water supplies having a desired flow rate and/or temperature.122. A method according to claim 121 wherein the first and second flow control valves each include a valve member assembly configured such that, when in use, fluid flowing through the valve cxerts substantially no net force on the valve member assembly.123. A method according to claim 121 or claim 122 wherein the first and second flow control valves each include a valve inlet chamber to receive water from the associated water supply and having first and second outlets opening to a mixing chamber.124. A method according to claim 123 wherein the first and second outlets are arranged at opposite ends of the inlet chambcr and arc axially aligned and provide first and second valve seats for co-operating with first and second valve members connected to a common spool coupled to an actuator for adjusting the first and second valve members relative to the first and second valve seats for controlling flow of water from the inlet chamber to the outlet chamber.125. A method according to claim 124 wherein, in use, fluid flowing through each flow control valve exerts a force on each valve member wherein the force on the first valve member is substantially equal to and in the opposite direction to the force exerted on the second valve member.126. A method of controlling tiow rate of outlet water from a flow control valve, the method including connecting the flow control valve to a water supply, configuring the flow control valve so that an operating force to actuate the flow control valve is substantially independent of water flow, and controlling the flow control valve to output a flow of the water having a desired flow rate.127. A method according to claim 126, wherein the flow control valve includes a valve niember assembly configured such that, when in use, fluid flowing through the valve exerts substantially no net force on the valve member assembly.128. A method according to claim 126 or claim 127, wherein the flow control valve includes a valve inlet chamber to receive water from the water supply and having first and second outlets opening to an outlet chamber.129. A method according to claim 128, wherein the first and second outlets are arranged at opposite ends of the inlet chamber and arc axially aligned and provide first and second valve seats for co-operating with first and second valve members connected to a common spool coupled to an actuator for adjusting the first and second valve members relative to the first and second valve seats for controlling flow of water from the inlet chamber to the outlet chamber.130. A method according to claim 129, wherein, in use, fluid flowing through the flow control valve exerts a force on each valve member wherein the force on the first valve member is substantially equal to and in the opposite direction to the force exerted on the second valve member.131. A method according to any of claims 121 to 130, wherein the outlet water is supplied to an outlet of a water delivery device.132. A method according to claim 131, wherein the water delivery dcvicc is a shower head.133. A method according to claim 131, wherein the water delivery dcvicc is a faucet.134. A method according to claim 133, wherein the faucet is selected from a bath tap, a sink tap and a basin tap.135. A method according to any of claims 131 to 134, wherein the fluid delivery device includes the mixer valve of any of claims I to 46 or the flow control valve of any of claims 74 to 118.136. A mixer valve substantially as described herein with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.137. A mixer valve substantially as described herein with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings as modified by Figures 5 and 6 or Figure 7 of the accompanying drawings.138. A shower head substantially as described herein with reference to and as illustrated in 8a and 85 or Figure 10 of the accompanying drawings.139. A fluid delivery device substantially as described herein with reference to and as illustrated in Figures 9a and 9b of the accompanying drawings.140. A mixer valve substantially as described herein with reference to Figures 1 Ia to lie of the accompanying drawings.141. A flow control valve substantially as described herein with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.142. A flow control valve substantially as described herein with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings as modified by Figures 5 and 6 or Figure 7 of the accompanying drawings.143. A flow control valve substantially as described herein with reference to Figure 1 Ic of the accompanying drawings.Amended claims have been filed as follows:-CL Al NI S 1. A mixer valve for use in controlling mixing of two supplies of water having different temperatures comprising a cold water inlet adapted to receive a supply of cold water, a hot water inlet adapted to receive a supply of hot water, a water outlet adapted to output cold water or hot water or a mixture thereot and a first flow control valve for controlling the flow of cold water from the cold water inlet to the water outlet and a second flow control valve for controlling the flow of hot water from the hot water inlet to the water outlet, each of the first and second flow control valves including a valve inlet communicating with the associated water inlet, first and second, separate valve outlets communicating with the water outlet and a valve member assembly to control the flow of water through the valve outlets, wherein each valve member assembly includes a first valve member adapted to engage with a first valve seat associated with the first valve outlet in a closed position of the flow control valve and a second valve membcr adapted to engage with a second, separate, valve seat associated with the second valve outlet in the closed position of the flow control valve, wherein the first valve member is arranged to be urged closed by water entering through the valvc inlet and thc sccond valve mcmbcr is arranged to be urged opcn by C watcr entering through the valvc inlet such that, when in use, water flowing through the first flow control valve exerts substantially no net force on the valve member C assembly of the first flow control valve and water flowing through the second flow control valve exerts substantially no net force on the valve member assembly of the second flow control valve.2. A mixer valve according to claim 1, in which the valvc inlet of each flow control valve is located between the first valve member and the second valve member of the valve member assembly.3. A mixer valve according to claim 1 or claim 2, in which each flow control valve includcs an inlct chamber and the valve inlet of cach flow control valve opens into the inlet chamber.4. A mixer valve according to claim 3, in which the first and second valve outlets of each flow control valve arc arranged at opposite ends of the inlet chamber.5. A mixer valve according to claim 3 or claim 4, in which the mixer valve includes a mixing chamber that includes the water outlet with the mixing chamber arranged to receive water from the first and second valve outlets of each flow control v a I v e.6. A mixer valvc according to claim 5, in which thc first and second valve outlcls are of similar size.7. A mixer valve according to any of claims 4 to 6, in which the first and second valve outlets are axially aligned.8. A mixer valve according to claim 7, in which the first and second valve members of each valve member assembly are connected to a spooi coupled to an actuator which controls the position of the valve members relative to their respective valve seats. C1)9. A mixer valve according to claim 8, in which the actuator comprises an clectrically powcrcd motor.10. A mixer valve according to claim 9, in which the motor comprises a stepper 0 motor.11. A mixer valve according to any of claims 8 to 10, in which the first and second valve seats are located within the first and second valve outlets.12. A mixer valve according to claim II, in which the first and second valve seats include a cylindrical bore portion of the valve outlets in which the first and second valve members are slidably received in the closed position.13. A mixer valve according to any of claims 8 to 10, in which the first and second valve seats arc located at one end of thc first and second valve outlets.14. A mixer valve according to claim 13, in which the first and second valve seats include an end face of the valve outlets against which the first and second valve members seat in the closed position.15. A mixer valve according to any of claims 5 to 14, in which the first valve member of the valve member assembly of each flow control valve is received in the inlet chamber in an open position of the flow control valve and the second valve member is received in the mixing chamber in the open position of the flow control valve.16. A mixer valve according to any preceding claim, in which the mixer valve includes a housing that houses the first and second flow control valves and includes apertures that form the cold water inlet, the hot water inlet and the water outlet.17. A mixer valve according to claim 16, in which the housing is made of metal or alloy and includes an electrically powered heating device for thernially disinfecting the mixer valve.18. A mixer valve according to claini 17, in which the mixing valve is disabled during a thermal disinfection cycle to prevent discharge of water.0 19. A mixer valve according to claim 18, in which the thermal disinfection cycle includes a heating cycle to heat the housing to a temperature sufficient to disinfect 0 waterways within the housing and a cool down cycle to allow the housing and water contained in the valve to cool down after the heating cycle.20. A mixer valve according to any preceding claim, in which the first and second flow control valves are controlled in response to water temperature and/or flow rate.21. A mixer valve according to claim 20, in which a sensor device is arranged to monitor the temperature and/or flow rate of the outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.22. A mixer valve according to claim 20, in which a sensor device is arranged to monitor the temperature of the hot and cold water and/or flow rate of the outlet water and the flow control valves are controlled to achieve and maintain a user selected outlet water temperature and/or flow rate.23. A plumbing fitting including the mixer valve of any one of claims 1 to 22.24. A plumbing fitting according to claim 23, in which the fitting comprises a water delivery device.25. A plumbing fitting according to claim 23 or claim 24, in which the fitting comprises a shower head.26. A plumbing fitting according to claim 23 or claim 24, in which the fitting comprises a faucet.27. A plumbing fitting according to claim 26, in which the faucet is selected from a bath tap, a sink tap and a basin tap.28. A water supply system including the mixer valve according to any of claims I to 22.O 29. A water supply system including the plumbing fitting according to any of claims 23 to 27.30. A method of controlling flow rate and/or temperature of outlet water from a mixer valve, the method including providing the mixer valve with a cold water inlet, a hot water inlet, a water outlet, a first flow control valve for controlling flow of cold water from the cold water inlet, and a second flow control valve for controlling flow of hot water from the hot water inlet, providing each flow control valve with a valve inlet communicating with the associated water inlet, two valve outlets communicating with the water outlet and a valve member assembly to control the flow of water through the respective flow control valve, connecting the cold water inlet to a cold water supply, connecting the hot water inlet to a hot water supply, wherein the cold and hot water supplies have different temperatures, providing each valve member assembly with a first valve member adapted to engage with a first valve seat in a closed position of the associated flow control valve and a second valve member adapted to engage with a second, separate, valve seat in the closed position of the associated flow control valve so that, the first valve member is arranged to be urged closed by water entering through the valve inlet and the second valve member is arranged to be urged open by water entering through the valve inlet such that, when in use, water flowing through the first flow control valve exerts substantially no net force on the valve member assembly of the first flow control valve and water flowing through the second flow control valve exers substantially no net force on the valve member asscmbly of the second flow control valve so that an operating force to actuate the first and second flow control valves is substantially independent of water flow, and controlling the first and second flow control valves separately or in combination and outputting a flow of cold water or hot water or a blend of the cold and hot water having a desired flow rate and/or temperature.31. A method according to claim 30 wherein the first and second flow control valves each include a valve inlet chamber to receive water from the associated water inlet and the valve outlets open to a mixing chamber.32. A method according to claim 31 wherein the valve outlets are arranged at opposite ends of the inlet chamber and are axially aligned.0 33. A method according to claim 31 or claim 32 wherein the first and second valve members are connected to a common spool coupled to an actuator for adjusting the 0 first and second valve members relative to the first and second valve seats for controlling flow of water from the inlet chamber to the mixing chamber.34. A method according to any of claims 30 to 33 wherein, in use, water flowing through each flow control valve exerts a force on each valve member wherein the force on the first valve member is substantially equal to and in the opposite direction to the force exerted on the second valve niember.35. A mixer valve substantially as described herein with reference to and as illustrated in Figures ito 4 of the accompanying drawings.36. A mixer valve substantially as described herein with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings as modified by Figures 5 and 6 or Figure 7 of the accompanying drawings.37. A shower head and mixer valve substantially as described herein with reference to and as illustrated in 8a and Sb or Figure 10 of the accompanying drawings.38. A water delivery device and mixer valve substantially as described herein with reference to and as illustrated in Figures 9a and 9b of the accompanying drawings.39. A mixer valve substantially as described herein with reference to Figures ha to lie of the accompanying drawings. C') aD