Abstract:
A mixer valve is shown which has two valves controllable by a mix controller to determine the ratio of fluid entering the mixer valve from two respective inputs, such as a hot fluid input and a cold fluid input, and a third valve controllable by a flow controller to determine the flow rate of fluid out of the mixer valve. Thus, the mixing proportion of the input fluids and the output flow rate are independently controllable. The mixer valve is suitable for incorporation into a mixer tap.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to mixer valves, i.e. units which receive two or more fluid inputs (e.g. hot and cold water) and are arranged controllably to produce a mixed fluid output. Mixer valves are typically used in taps (faucets), showers and the like.  
         [0003]     2. Summary of the Prior Art  
         [0004]     Conventional mixer valves typically have a housing which receives two fluid inputs and provides them to a mixing unit which comprises two ceramic discs, which are movable relative to one another. In one arrangement, one of the ceramic discs is fixed in the housing with the other being movable by an external controller. The fixed disc has two holes therethrough which receive fluid from the respective inputs. The fixed disc has another hole in fluid communication with an outlet to permit fluid to leave the housing. The movable plate includes a mixing chamber (e.g. a recess) which can selectively join either or both input holes to the output hole so that fluid can flow from the inputs to the outlet, mixing in the mixing chamber as it does so.  
         [0005]     The above type of arrangement is used in a single lever mixing cartridge, which provides separate control of the mixing proportion and flow rate through the provision of a single control lever that is movable in two distinct ways. Typically, the lever is tiltable to control flow rate, e.g. by moving the mixing chamber into or out of fluid communication with the input holes, and rotatable to control mixing proportion (e.g. temperature). However, such complex movement is not always easily or conveniently controllable, e.g. in small spaces or where the mixer valve needs to be at a distance from an operating device.  
         [0006]     US 2005/0076960 proposes a mixer valve where the hot and cold inputs are connected to respective valve cartridges, which are independently operated by separate tap controllers. The valve cartridges used are standard: fluid is received into the base, and flows out of an outlet in the cartridge side wall under the control of a valve, which is operated by a rotatable control spindle which protrudes from the top of the cartridge. There is a geared connection between the tap controllers (e.g. handle) and the control spindles of the valve cartridges. The gearing ratio is arranged to give make the operation angle of the tap controllers larger than the operation angle of its respective cartridge control spindle. This can give greater mechanical advantage and facilitate temperature control. However, the flow rate out of the mixer valve is not easily controlled without affecting the mixing proportion (temperature) of the output fluid.  
       SUMMARY OF THE INVENTION  
       [0007]     One aim of the present invention is to provide an improved mixer valve where mixing proportion and output flow rate are independently controllable in a simple fashion. Combinations of different types of motion (e.g. the tilting and rotating of known devices) is preferably avoided; for example, the mixing proportion and output flow rate may be controllable using only rotational motion.  
         [0008]     At its most general, the present invention provides a mixer valve having three valve portions associated with fluid inputs and outputs so that fluid flow out of the mixer valve is controllable separately from (i.e. independently of) the proportion of fluid received from each input.  
         [0009]     Thus, according to the present invention there is provided a mixer valve for mixing fluid received from first and second inputs to provide an output of mixed fluid, the mixer valve having: a first valve with an inlet in fluid communication with the first input; a second valve with an inlet in fluid communication with the second input; a third valve with an inlet in fluid communication with outlets of the first and second valves, and an outlet arranged to provide the output of mixed fluid; a mix controller arranged to operate the first and second valves; and a flow controller arranged to operate the third valve. The flow controller may therefore control the flow rate of fluid leaving the mixer valve. The flow controller may be able to completely close the third valve so that no fluid may leave the mixer valve. The operation of the flow controller is independent of the operation of the mix controller, so that the flow rate of fluid leaving the mixer valve may be controllable without affecting the mix proportion of the input fluid.  
         [0010]     Preferably the mixer valve comprises a housing which contains the first, second and third valves. The housing may enclose a mixing chamber forming part of the fluid communication between the outlets of the first and second valves and the inlet of the third valve, the mixing chamber providing a space to promote thorough mixing so that the output is a substantially uniform mixture of the input fluids.  
         [0011]     Preferably, the mix controller is arranged to operate the first and second valves in a complementary fashion. The first and second valves are preferably controlled by a common mix control element. The common mix control element may interconnect the first and second valves, so that when the first valve opens the second valve closes and vice versa. Such an interconnected controller promotes smooth variation of the input mix proportion. The combined flow rate from the fluid outlets of the first and second valves may be constant, although this may in practice depend on the fluid pressures of the inputs. This means that a constant input flow may be provided to the third valve, which therefore improves the control the third valves gives over output flow rate.  
         [0012]     Preferably, one or more or all of the first, second and third valves are standard ceramic valve cartridges. Preferably, each valve cartridge has its input in its base and a valve plate or plates arranged to open or close a fluid passageway between the base and the outlet to permit fluid flow out of the outlet when the passageway is open.  
         [0013]     Preferably, each valve cartridge has an control spindle (e.g. upstanding from the cartridge) which is rotatable to open and close the valve. In the preferred embodiment, the bases of two of the valve cartridges are attached to the fluid inputs, i.e. a first valve cartridge may receive hot water, and the second valve cartridge may receive cold water. The output supplies of the first and second valve cartridges are preferably in fluid communication with the base of a third valve cartridge. In this arrangement, a mixing chamber may be provided in the volume (space) between the output suppliers of the first and second valve cartridge and the base of the third valve cartridge.  
         [0014]     The output supply of the third valve may be directly connectable to a conduit or other fluid conveying means in order to carry fluid from the mixer valve to an outlet apparatus, e.g. tap. Of course, the mixer valve may be an internal or even integral component of such an outlet apparatus.  
         [0015]     Preferably, the mix controller is arranged to rotate the control spindles of the first and second valve cartridges. Preferably, rotation of the control spindles is controlled in a complementary fashion, i.e. a common control element may interconnect them to cause rotation of both control spindles.  
         [0016]     Preferably, a first mix controller operation causes the first valve cartridge to open and the second valve cartridge to close, and a second mix controller operation causes the second valve cartridge to open and the first valve cartridge to close. The common control element may be a rotatable shaft, and the first and second mix controller operations preferably correspond to opposite senses of rotation of the shaft.  
         [0017]     The control spindles of the first and second valve cartridges may have gears attached to them that are operably connected to a main gear or other drive means rotatable by the mix controller. Preferably, the mix controller includes a rotatable shaft coupled to the main gear.  
         [0018]     The gearing ratio between the main gear and gears attached to the control spindles may be 1:1, or there may be a step-up or step-down arrangement. Preferably the ratio is the same for both control spindles. For example, a step-down arrangement, which may give the rotatable shaft a larger operation angle than the valve cartridge control spindle, may be used to give improved leverage. Alternatively, a step-up arrangement, which may give the rotatable shaft a smaller operation angle than the valve cartridge control spindle, may be used to reduce the amount of movement required by the rotatable shaft. This can be useful where space is limited. Thus, a conventional quarter turn valve cartridge (having an operation angle of 90° between full open and full closed) may require the rotatable shaft to be rotated by more than 90° (e.g. 120° or more) in a step-down mechanism, or by less than 90° (e.g. 600 ° or less) in a step-up mechanism.  
         [0019]     The rotatable shaft is preferably adapted to be connected to a user-operated mechanism belonging to an outlet (e.g. tap) assembly. The user-operated mechanism may be a conventional rotary handle. The rotatable shaft may be connected to it by conventional means, e.g. a splined head matingly receivable in a correspondingly splined recess.  
         [0020]     Preferably, the flow controller is arranged to rotate the control spindle on the third valve cartridge. This may also be achieved by a gear attached to the control spindle which is operably connected (e.g. meshed with) a main gear or other drive means rotatable by the flow controller. As above, the gearing ratio between the main gear and gear attached to the control spindle may be 1:1, or there may be a step-up or step-down arrangement, depending on the constraints of leverage and/or space.  
         [0021]     Preferably, the flow controller includes a rotatable shaft coupled to it main gear. The rotatable shaft is preferably adapted to be connected to a user-operated mechanism belonging to an outlet (e.g. tap) assembly. For example, the user-operated mechanism may be a conventional rotary handle, or a tiltable lever, etc.  
         [0022]     Both the mix controller and flow controller may include rotatable shafts to operate their respective valve cartridges. In this case, the rotatable shafts may be coaxial. For example, the control shaft for one of the mix or flow controller may be a sleeve surrounding and rotatable relative to the rotatable shaft for the other controller. Preferably, the main gears attached to the rotatable shafts also rotate about a common axis. Preferably they are axially displaced to avoid interfering with one another and cluttering the interior of the mixer valve. Since the gears attached to the valve cartridges have a limited rotational extent, the main gears may be provided with meshing teeth only around part of their circumference. This can save space inside the mixer valve and also lead to a more lightweight product.  
         [0023]     A mixer valve as described above has general applicability, and may be incorporated in all types of mixer taps, or with the fluid outlet assemblies that require mixing. Another aspect of the present invention may provide a fluid outlet assembly or mixer tap that includes such a mixer valve. The mixer valve may be incorporated into the housing of such an assembly, or it may be located out of sight (e.g. behind a wall or below a work surface). 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     Examples of the present invention will now be described with reference to the accompanying drawings, in which:  
         [0025]      FIG. 1  shows a mixer tap having a mixer valve according to an embodiment of the invention;  
         [0026]      FIG. 2  shows a cross-section along the line A-A of the mixer tap shown in  FIG. 1 ;  
         [0027]      FIG. 3  shows a close-up perspective view of the mixer valve shown in  FIG. 1 ;  
         [0028]      FIG. 4  shows the opposite view of the mixer valve shown in  FIG. 3 ;  
         [0029]      FIG. 5  shows a side view of a mixer valve which is an embodiment of the invention in isolation;  
         [0030]      FIG. 6  shows a cross-section along the line C-C through the mixer valve of  FIG. 5 ;  
         [0031]      FIG. 7  shows a cross-section taken along the line B-B of the mixer valve shown in  FIG. 5 ;  
         [0032]      FIG. 8  shows another side view of the mixer valve shown in  FIG. 5 ;  
         [0033]      FIG. 9  shows a cross-section through the line E-E of the mixer valve shown in  FIG. 8 ;  
         [0034]      FIG. 10  shows a cross-section taken along the line D-D of the mixer valve shown in  FIG. 8 ;  
         [0035]      FIG. 11  shows a perspective view of another mixer tap having a mixer valve which is an embodiment to the present invention;  
         [0036]      FIG. 12  shows a side view of the mixer tap shown in  FIG. 11  when mounted on a work surface; and  
         [0037]      FIG. 13  shows a cross-section taken along the line F-F of the mixer tap shown in  FIG. 12 . 
     
    
     DETAILED DESCRIPTION  
       [0038]      FIG. 1  shows a mixer tap  10  that incorporates a mixer valve  20  that is an embodiment of the present invention. The mixer valve  20  includes a housing  15  arranged to receive fluid inputs via supply conduits  14 , 16  from main hot and cold water supply pipes respectively. An output conduit  18  extends away from the bottom of housing  15  and loops around the mixer valve  20  to be fed through a hole in the work surface  42  into a spout  32 , terminating in a conventional spray head  34 . The spout  32  is mounted on the work surface via a housing  26 . A rigid upstanding tube  24  extends through a hole in the work surface  42  and has the mixer valve  20  mounted on it via casing  17 . The tube  24  is secured in place, i.e. prevented from rotating or moving axially with respect to the work surface  42 , by a backing nut  27 . A cut-out hole  25  is formed in the tube  24  to allow the output conduit  18  to pass into the tube and through a passageway in the middle of the housing  26 . A guide pipe  22  is attached by a ring  21  and lug  23  (see  FIG. 2 ) to the tube  24 . The guide pipe  22  helps to orientate the output conduit  18  correctly so that it enters the cut-out  25  in the tube  24  without excessive bending or interference from the edges of the cut-out  25 .  
         [0039]     As shown in detail in  FIG. 2 , rotatable radially protruding levers  30 , 31  are operably connected to rotatable control elements  44 , 46  in the mixer valve  20 . The levers  30 , 31  are used to control the mixing proportion of hot and cold water received in the mixer valve and the output flow rate of fluid away from the mixer valve in the manner described in detail below.  
         [0040]     In  FIG. 2 , it can be seen that housing  26  is formed in one piece with tube  24 , and has control sleeves  36 , 38  coaxially mounted therein. The spout  32  is mounted in the top part of housing  26 , where it is held in place by stopper  39 . The control sleeves  36 , 38  are able to rotate relative to one another and to the tube  24 . Inner control sleeve  38  has an upper head portion  37  connected to lever  31 , and outer control sleeve  36  has an upper head portion  35  connected to lever  30 . These connections are covered by respective trim covers  28 , 29 . Both the control sleeves  36 , 38  have cut-out portions arranged to overlap with the cut-out  25  in tube  24  to enable the output conduit  18  to pass cleanly into the inside of the housing  26 . The gearing ratios described below may be selected to give a small operation angle to the control sleeves  36 , 38  so that cut-outs having a smaller circumferential extent can still fully overlap with the cut-out  25  in tube  24 .  
         [0041]     The base  40  of inner control sleeve  38  has a central, internally splined, through hole  43  arranged to matingly receive a correspondingly splined upstanding peg  45  of flow control element  44 . Thus, rotation of inner control sleeve  38  (via upper lever  31 ) causes rotation of flow control element  44 .  
         [0042]     Outer control sleeve  36  is connected to mix control element  46 , so that rotation of lower lever  30  causes rotation of the mix control element  46 .  
         [0043]     As shown in  FIGS. 3 and 4 , flow control element  44  has a toothed gear  62  radially protruding therefrom so as to mesh with a gear wheel  56  mounted on the control spindle (not shown) of a conventional ceramic disc valve cartridge  50 . Meanwhile, mix control element  46 , which is formed in the shape of an annulus, thereby allowing flow control element  44  to pass through it, has a depending connector plate  55  attached to another gear  64 , whose radially protruding teeth mesh with gears  58 , 60  mounted on the control spindles (not shown) of two further ceramic plate valve cartridges  52 , 54 . To maintain smooth rotation, the gears  62 , 64  controlled by the flow and mix control elements  44 , 46  are rotatably mounted on an upstanding axle  57 , which is mounted in the base  15  of the mixer valve  20 . Outer casing  17  securely attaches base  15  to a tube  24  to prevent the base  15  from rotating when the mix or flow control elements  44 , 46  are rotated. Casing  17  also acts as a protective cover for the gear mechanism.  
         [0044]     FIGS.  5  to  9  show the internal configuration of the mixer valve  20  in more detail. Briefly, the input fluid supplies  14 , 16  are respectively connected to the inputs of valve cartridges  52 , 54 , whose control spindles are operated by mix control element  46 . The outlets from these valve cartridges  52 , 54  are connected to the inlet of valve cartridge  50 , whose control spindle is operated by flow control element  44 . The outlet of valve cartridge  50  is connected to output conduit  18  so that any fluid flowing out of the mixer valve  20  is carried by output conduit  18  to spray head  34 .  
         [0045]     In detail,  FIG. 5  shows the outlet tube  70  to which the output conduit  18  is attached. As shown in  FIG. 6 , a central passageway  72  is formed inside the base  15  to carry fluid out of the tube  70 . Fluid is provided to the central passageway  72  from the outlet  73  of the valve cartridge  50  via a radial passageway  76 . Fluid enters the inlet of valve cartridge  50  from upstanding passageway  78 , which is in fluid communication with mixing chamber  74 , which has an annular form, as shown in  FIG. 7 . Thus, fluid entering the mixing chamber  74  flows into valve cartridge  50  via upstanding passageway  78 . If the valve is open, the fluid will leave the mixer valve  20  via passageways  72 , 76 . The outlets of the valve cartridges that receive fluid input open into mixing chamber  74 .  
         [0046]      FIG. 8  shows another side view of the mixing valve  20 , where the axial displacement of the valve cartridges  50 , 52 , 54  can clearly be seen. Valve cartridge  50  projects further out of the base  15  than valve cartridges  52 , 54 . This allows the operating gears  62 , 64  to be axially displaced from one another. In fact it allows them to share a common axis whilst maintaining their independence. It also allows the mixer valve  20  to be compact in the radial direction.  
         [0047]     The cross-section of  FIG. 9  demonstrates how fluid is provided from the first two valve cartridges  52 , 54  to the mixing chamber  74 . Fluid enters upright passageways  86 , 88  from input supplies  14 , 16 . Input passageways  86 , 88  respectively carry the fluid into the inlets of valve cartridges  52 , 54 . The outlets  90 , 92  of valve cartridges  52 , 54  are in fluid communication with the mixing chamber  74 .  
         [0048]      FIG. 10  shows that a single gear  64  is used to control both gears  58 , 60  mounted on the control spindles  82 , 84  of valve cartridges  52 , 54 . Since output flow rate is controlled separately by the action of gear  62  with gear  56  (which is shown mounted on the control spindle  80  of valve cartridge  50  in  FIG. 10 ), there is no need for the mix control mechanism to exhibit any flow rate control. In other words, mix control mechanism need not cause both valves to be closed at the same time. That is, the mechanism represented by main gear  64  and valve cartridge gears  58 , 60  need only present the capability of varying the relative proportion of fluid permitted through valve cartridges  52 , 54 . At one extreme, valve cartridge  52  is fully open and valve cartridge  54  is fully closed. The other extreme is represented by valve cartridge  52  being fully closed and valve cartridge  54  being fully open. By setting the initial position of the control spindles and main gear  64  correctly, the relative proportion of fluid permitted through valve cartridges  52 , 54  can be varied smoothly (e.g. linearly) between these two extremes. This is brought about by meshing equally sized gears  58 , 60  with the same main gear  64 .  
         [0049]     FIGS.  11  to  13  show a mixer tap  100  with another mixer valve  200  according to the present invention. As shown in  FIG. 12 , mixer valve  200  is arranged to be mounted above the work surface  42  within the main housing  106 , 108  of a mixer tap assembly  100 . As before, input supplies  14 , 16  are connected to the base  15  of the mixer valve  200 . Radially protruding levers  30 , 31  are turned to rotate gears in the same way as shown in FIGS.  5  to  9 . As the mixer valve  200  is above the work surface in this embodiment, there is no need for control sleeves to connect the levers  30 , 31  to the mix and flow control elements. Connection is more direct, as shown in  FIG. 11 .  
         [0050]     One difference in this embodiment is that the output from valve cartridge  50  is provided to a supply pipe  104  that extends out of the top of base  15  and is connected to the base of spout  102 . Other than this, the internal mechanisms of the mixer valve  200  are the same as those illustrated in FIGS.  5  to  9 .  FIG. 13  shows the presence of a mixing chamber  110 .  
         [0051]     In use, therefore, the user operates one of the radially protruding levers  30 , 31  to control the flow rate of fluid ejected from the mixer valve  20 , 200  to be carried to the spout or other outlet of the assembly in which the mixer valve is mounted. Independently of the flow rate, the user can control the mixing proportion (i.e. the temperature, where the fluid inputs are hot and cold water) of the ejected fluid by operating the other one of the radially protruding levers  30 , 31 .