Abstract:
A diverter valve comprises a housing having inlets, a first outlet, and a second outlet. The inlets are connected to hot and cold water supplies, and mixing of the hot and cold water occurs both inside the housing and inside a mixing chamber external to the valve. The first outlet is connected to a spout, and the second outlet is connected to a spray unit. A valve element is mounted in the housing, movable between a closed position and an open position with respect to the first outlet. A piston member comprising a first piston at the bottom end of the valve element, and a second smaller piston at the top end of the valve is responsive to pressure differential between the second outlet and the inlet for movement to a first ad second position. When a lower pressure exists at the second outlet, the piston member moves to the second position, closing off the first outlet. The valve also includes a flow regulator to regulate the flow through the second outlet. Fluid is directed into the flow regulator by channels running through the bottom piston. The flow regulator allows pressure to build up inside the valve, providing an increased closure force on the second outlet when the first outlet is open. An inverted cup washer prevents fluid leakage from the second exit by any other route than through the flow regulator. Build up of water inside this cup washer pushes it against the housing, providing an anti-knocking mechanism. The diverter valve may be included in a faucet assembly along with a separate isolated channel for filtered water.

Description:
INTRODUCTION AND BACKGROUND  
         [0001]    This invention relates to valve structures and more particularly to a diverter valve that incorporates an improved closure mechanism and anti-knocking mechanism.  
           [0002]    Diverter valves are commonly used in water tap or faucet assemblies to divert water between a spout and a hand spray. When the spray is operated, the diverter valve shuts off the flow of water to the spout. When the spray is shut off, the diverter valve automatically adjusts to allow water to flow from the spout again. Such systems are particularly used in domestic environments, as well as commercial establishments,  
           [0003]    A common method of implementing this automatic diverter system is by means of a piston mechanism. The valve comprises a housing containing a valve member shaped to act as a piston. The valve member is movable from a first position, in which the outlet to the spout is open, to a second position, in which the outlet to the spout is closed off. The piston is responsive to a difference in pressure between the spray outlet and the inlet, so that when the spray is open, the piston moves to close off the spout. Additionally, such a valve may comprise both hot and cold water inlets, such that mixing of the hot and cold water occurs. For example, Moen (U.S. Pat. No. 2,949,933) describes a hot and cold water mixing valve, which can also automatically divert the mixed water from a principle outlet passage to an auxiliary outlet passage when a control valve on the auxiliary passage is opened.  
           [0004]    However, a problem with existing diverter valves is that they only operate over a limited pressure range. At high pressures, leakage tends to occur. At low pressures, there is not enough force to close the seal on the spout properly, again resulting in leakage.  
           [0005]    Another problem is the tendency for knocking to occur. Knocking is when a valve member is quickly moved from one position to the second position and rebounds back, thereby producing an audible hammering effect in the water line. It can be sufficiently loud as to make someone using the spray/spout system to believe that there is something seriously wrong with it. In U.S. Pat. No. 4,577,653 (Masco Corporation), a new design of valve is described, which is intended to reduce knocking of the valve member in the housing. This is achieved largely by prongs at the bottom of the upper housing part which bear on the conical mid-portion of the valve member. However, the design of Masco&#39;s valve is extremely complicated. The present invention aims both to improve substantially on the pressure range over which the valve will operate, and to reduce the amount of knocking which occurs, based on a design which is fairly straightforward and easy to construct.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a diverter valve, comprising a housing having an inlet, a first outlet, and a second outlet, a valve element mounted in said housing, movable between a closed position and an open position with respect to the first outlet, a piston means for moving said valve element, with said piston means being responsive to pressure differential between said second outlet and said inlet such that when a lower pressure exists at said second outlet, said piston means moves said valve element to said closed position. A flow regulator regulates the flow through the second outlet, so that as the water pressure in the housing increases, the restricting effect on the flow by the flow regulator increases, and as the water pressure in the housing decreases, the restricting effect on the flow by the flow regulator decreases.  
           [0007]    Preferably, the piston means comprises a first piston at the bottom end of the valve element, and a second piston at the top end of the valve element. The first piston has a larger effective cross section than the second piston, resulting in the fluid in the chamber exerting a larger force on the first piston than on the second piston. The valve additionally comprises a flow regulator adapted to regulate the flow rate through the second outlet. Preferably, the diverter valve includes channelling means for channelling fluid through the flow regulator. Preferably, this fluid channelling means comprises one or more channels running through the length of the first piston. Preferably, the diverter valve also includes leakage prevention means for preventing fluid leakage from the second outlet by any other route than through the flow regulator. Preferably, the leakage prevention means comprises an inverted flexible cup washer, such as of rubber or other suitable polymer material. Preferably, the diverter valve comprises a second inlet, such that hot water enters via the first inlet, and cold water enters via the second inlet, and the hot and cold water mix inside the housing. The hot and cold water may enter the valve independently, or they may partially mix beforehand in a mixing chamber outside the housing.  
           [0008]    The first outlet may be connected to a spout, and the second outlet may be connected to a spray. The housing of the valve may be integral with the spout, may be attached to the spout (for example, by welding or soldering) or may be separate from the spout. Having the housing fixed to the spout has the advantage that there are fewer parts to put together during assembly or repair of a tap system which utilises the diverter valve. If the housing was integral with the spout, they could be manufactured as a single item.  
           [0009]    It is also possible to have a separate channel by which filtered water can pass through to the spout, but not to the spray. This would be useful to provide drinking water from the same spout as is used for hot/cold water in a sink. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:  
         [0011]    [0011]FIG. 1 shows a perspective view of a prior art design of diverter valve;  
         [0012]    [0012]FIG. 2 shows a sectional view of the valve of FIG. 1, located within an outer body;  
         [0013]    [0013]FIG. 3 shows a perspective view of the diverter valve according to a first embodiment of the invention;  
         [0014]    [0014]FIG. 4A shows a side view of the valve of FIG. 3. FIG. 4B gives a sectional view along line A-A of FIG. 4A;  
         [0015]    [0015]FIGS. 5A and 5B give a more detailed view of channels running through a lower piston element in the valve of FIG. 8. FIG. 5A shows a bottom view and FIG. 5B shows a side view;  
         [0016]    [0016]FIGS. 6A to  6 C show a flow regulator. FIG. 6A gives a bottom view, FIG. 6B is a cross-section along line A-A of FIG. 6A, and FIG. 6C shows the fitting mechanism of the flow regulator in more detail;  
         [0017]    [0017]FIG. 7 is an exploded perspective view of a second embodiment of the present invention;  
         [0018]    [0018]FIGS. 8A to  8 E show a detailed view of a valve member of the second embodiment;  
         [0019]    [0019]FIG. 8A is a side view; FIG. 8B is an underneath view; FIG. 8C is a cross section through line A-A of FIG. 8C; FIG. 8D is a perspective view from above and FIG. 8E is a perspective view from below.  
         [0020]    [0020]FIGS. 9A to  9 E show a detailed view of an upper valve housing of the second embodiment. FIG. 9A is a side view, FIG. 9B is a top view, FIG. 9C is a cross sectional view along line A-A of FIG. 9B, FIG. 9D is a cross sectional view along line B-B of FIG. 9B and FIG. 9E is a perspective view from above;  
         [0021]    [0021]FIGS. 10A to  10 B show a detailed view of the guide plate of the second embodiment. FIG. 10A is a base view and FIG. 10B is a cross sectional view along line A-A of FIG. 10A;  
         [0022]    [0022]FIGS. 11A to  11 E show a detailed view of an outer housing of the second embodiment. FIG. 11A shows a side view, FIG. 11B shows a top view, FIG. 11C shows a cross section through line A-A of FIG. 11B, FIG. 11D shows a cross sectional view through line B-B of FIG. 11A, and FIG. 11E shows a side perspective view;  
         [0023]    [0023]FIG. 12 shows a base view of the faucet assembly incorporating the second embodiment;  
         [0024]    [0024]FIGS. 13A to  13 G show details of the faucet assembly of FIG. 2. FIG. 13A shows a front view, FIG. 13B shows a side view, FIG. 13C shows a cross section through line A-A of FIG. 13B, FIG. 13D shows a cross section through line B-B of FIG. 13A, FIG. 13E shows a cross section through line C-C of FIG. 13A) FIG. 13F shows a cross sectional view through line D-D of FIG. 13B, and FIG. 13G shows a base view;  
         [0025]    [0025]FIG. 14 shows a perspective view of the spout and valve assembly when fixed inside the faucet assembly, according to the second embodiment of the invention.;  
         [0026]    [0026]FIG. 15 shows an enlarged view of the valve assembly of FIG. 14;  
         [0027]    [0027]FIG. 16 shows a perspective view of the faucet assembly and spout of the second embodiment;  
         [0028]    [0028]FIG. 17A shows a side view of the spout and FIG. 17B shows a front view of the spout of the second embodiment;  
         [0029]    [0029]FIG. 18A shows a base view of the end-cap of the spout of FIG. 17, and FIG. 18B shows a cross sectional view along line A-A of FIG. 18A; 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]    [0030]FIG. 1 shows a prior art design of valve, in which a brass or plastic valve member  100  is contained within a brass housing  101 . The valve has two inlets  120 ,  121  and two outlets  109 ,  113 . The two inlets are used for hot and cold water. The path of the water, with the valve member  100  in the position shown, is indicated by arrows  106  and  107 . The inlets  120 , 121  access a common channel outside the housing with hot and cold water fed to the channel, so that mixed hot and cold water enters the housing, followed by further mixing inside the housing. The bottom outlet  113  is for connection to a spray unit and the top outlet  109  is for connection to a nozzle or spout. The valve member  100  is shaped in the form of a stem  105  with a piston  115  on the top end and a piston element  114  on the bottom end. The top piston  115  also acts as a closure element for the outlet  109  to the spout. The housing just below the top piston  115  is shaped with a ledge  125  on which the piston  115  rests in order to close off the spout outlet  109 . An O-ring seal  110  is located on the valve member  100  just above the top piston  115 , allowing the nozzle outlet  109  to be sealed shut when the valve member  100  is pushed downwards. On the end of the valve member  100 , next to the top piston  115 , is a triangular shaped guide  130  which guides the upper part of the valve member  100  within the housing  101  to minimise vibration. The effect of the triangular shape is to give a larger cross section to the waterway than, for example, a square shape. At the bottom of the valve, a rubber cup washer  102  is held in position between a bush  103  and a clip  104 . A lower piston is formed comprising both the bottom piston element  114  and the rubber cup washer  102 . The rubber cup washer effectively increases the area of the bottom piston beyond that of the bottom piston element  114  alone. Thus, the effective cross-section area of the bottom piston is larger than of the top piston  115  The flow of fluid to the spray is restricted by having to pass around the outer edge of the rubber cup washer  102 . On the outside of the housing are O-ring seals  111 ,  112  to allow sealed connections to be made to the spout and spray outlets, such that the outflow from these outlets can be isolated from each other and from the inlets. The entire housing fits within a cavity in a body of a faucet system. The central portion of the housing  101  acts as a pressure chamber  108 .  
         [0031]    In operation, hot  106  and cold  107  water come into the pressure chamber  108 . With the spray unit closed water will not flow through outlet  113 . The faucet spout (connected to outlet  109 ) is always open so water can flow through that. Thus there is a pressure differential on the upper piston  115 , but not on the lower piston. The pressure of the water in the pressure chamber  108  thus forces the valve member  100  upwards towards outlet  109 , so that water flows through the outlet  109 . When the spray unit is opened, water can flow through outlet  113 , and so there is now a pressure differential across both pistons  114 , 115  Due to the lower piston having a larger surface area than the upper piston  115 , the downward force (towards outlet  13 ) is greater than the upward force (towards outlet  109 ). The valve member  100  therefore moves downwards in the housing  101 , losing off the water supply to the nozzle, and causing the water to force past the rubber cup washer  102 . It will be appreciated that when we refer to ‘upwards’ and ‘downwards’ this refers to the direction of the outlets  109 , 113 . In use, the housing  101  could be mounted in any orientation.  
         [0032]    [0032]FIG. 2 shows a sectional view of the diverter valve of FIG. 1 located within an outer body  126  of a tap or faucet. A mixing chamber  122  is provided in the outer body  126  in which the hot and cold water partially mix before entering the valve. Mixing is then completed inside the pressure chamber  108 . The lower end of a top nozzle  123  is shown fluidly connected to outlet  109 . A channel  124  connects with outlet  113  and leads to a spray unit (not shown).  
         [0033]    The valve of FIGS. 1 and 2 operates in a range between 1 bar and 6 bar. Above 6 bar, there is a tendency for leakage from the spout when diverted to spray, especially with hot water. This is due to the lip of the rubber cup washer  102  softening and being dragged inwards by the flow of water. A pressure drop occurs in the central portion of the housing  108 , and thus some of the closing force on the nozzle seal  110  is lost. The valve of the invention has been designed to avoid this problem, and also to incorporate a simple mechanism to reduce knocking.  
         [0034]    [0034]FIG. 3 shows a valve according to a first embodiment of the invention. The arrangement is generally similar to the arrangement of FIGS. 1 and 2. The rubber cup washer  202  has been inverted to trap the water and form a seal between the outer lip of the washer  202  and the housing  201 . Again, the rubber cup washer  202  and the lower piston element  214  together form a lower piston, with larger effective cross section than the top piston  215 . The valve has a central waterway comprising several channels  219  through which the flow of water is routed to a standard flow regulator  216  that restricts the flow to a substantially constant rate over a range of water pressure. This results in an increase in pressure in the pressure chamber  208 , producing a much improved seal on the nozzle. The valve of the invention works between  1  bar and  10  bar. An additional beneficial effect is that the pressure of the water pushes and locks the cup washer  202  against the inside of the housing  201 , reducing the tendency for the valve member  200  to shuttle back and forth, hence reducing the chance of knocking.  
         [0035]    [0035]FIG. 4A shows a side view of the valve of the first embodiment. A sectional view along line A-A is given in FIG. 4B. The structure of the flow regulator  216  can be seen, where channels  230  allow fluid to pass through at a controlled rate. The flow regulator  216  is snapped into place in the housing  201  by forcing it through a tapered die  227 .  
         [0036]    [0036]FIG. 5 shows more detail of the channels through the lower piston. FIG. 5A shows a bottom view of the valve member, wherein six channels  228  are formed through the lower piston element  211  The edges of the top piston  215  can be seen behind the bottom piston element  214 . The lower end  229  of the valve member can be seen in the centre of the figure. FIG. 5B shows a side view of the lower piston element  214 . The six channels  228  extend through the tapered piston surface  229 .  
         [0037]    [0037]FIG. 6 shows the flow regulator in more detail. FIG. 6A gives a rear view, showing the six outlet channels  230  in the body  234  of the flow regulator. The flow regulator has a central pillar  231 , one end of which is fixed to the body  234  of the flow regulator. The other end of the central pillar  231  has a splayed shape, enabling the central pillar  231  to retain an O-ring  232  looped around it. The O-ring  232  is made of an elastic material.  
         [0038]    When the pressure in the waterway is increased, the O-ring  232  is forced against the restricting bars  233  surrounding the outlet channels  230  in the body  234  of the flow regulator. The higher the pressure, the more the O-ring  232  becomes flattened, thus progressively reducing the size of the waterway. In this way, a constant flow of water is maintained.  
         [0039]    [0039]FIG. 6B shows a section along line A-A of FIG. 6A. The flow regulator  216  is attached to the housing  201  by a snap fastening means comprising a tapered die  227 . FIG. 6C shows this snap fastening means in more detail.  
         [0040]    The embodiment of FIGS.  3  to  6  functions in the same general manner as the prior art embodiment of FIGS. 1 and 2, with the valve moving to close off the outlet  209  when the spray nozzle is opened. Water in chamber  208  then flows through channels  280  to the spray outlet. When the spray outlet is closed, valve member  200  moves towards nozzle outlet  209 , opening the flow channel through to the faucet nozzle.  
         [0041]    FIGS.  7  to  18  show a second embodiment of the invention, in which the valve housing is integrated with the spout of the faucet. As shown in FIG. 7, the valve assembly comprises an outer housing  301  which is attached to the inlet end  370  of the spout  371 . In this embodiment, the outer housing  301  is soldered to the spout with a solder ring placed in a groove in the outer housing  301 . The solder joint is concealed by a decorative ring held in place by an O-ring.  
         [0042]    An upper valve housing part  845  is inserted into the outer housing  301 , and sealed against it using an O-ring. A guide plate  346  and seating O-ring  347  are fitted into a channel  365  (FIG. 9) in the upper valve housing  345 . The end of the valve member  300  is fastened to the guide plate  346 . A flow regulator  316 , of similar design to the flow regulator  216  of the first embodiment, is positioned against the lower part of the valve member  300 . The lower part of the outer housing  301 , containing the valve assembly, is fixed in position inside the faucet body  380 , for example, by using a grub screw  366 .  
         [0043]    The individual parts of the valve assembly are shown in more detail in FIGS.  8  to  11 . FIGS. 8A to  8 E show the valve member  300  which comprises a small upper piston  315 , a larger lower piston  314  and a stem  305  joining the two pistons. The upper piston  315  has a guide pin  390  attached to its upper surface, which is for engaging with the guide plate  346 . The guide plate  846  snap fastens on to the guide pin  390 . The valve member  300  has a hollow  394  on the lower surface of the lower piston  814 , into which the flow regulator  316  is inserted. The lower piston  314  has a number of holes  391 , spaced evenly in a circular pattern around its central axis  392 . These holes are positioned such that when the flow regulator  316  is positioned inside the lower piston  314 , the holes  391  in the lower piston  314  will align with the holes of the flow regulator  316 . Two hooked projections  393  are positioned beside the hollow  394 . These allow easy removal of the valve member  300  from the outer housing  301 , e.g. during maintenance of the valve assembly, by levering the valve member  300  out using a screwdriver inserted against one of the hooked projections  393 .  
         [0044]    FIGS.  9 SA to  9 E show the upper valve housing  345  on enlarged scale. It has a channel  365 , running though it to allow water to pass through into the spout when the valve is open. The channel has a circumferential lip  367  on the bottom part of its inner surface. In operation, the upper piston  315  of the valve member  300  is located inside the channel  365 , and presses downwards against the lip  367  to seal off the channel  365  when the valve is in a closed position.  
         [0045]    [0045]FIGS. 10A and 10B show the guide plate  346 . This has a central channel  396 , into which the pin  390  of the valve member is inserted. The guide plate  346  also has a lip  395  protruding upwardly from the circumference of its top surface. The seating O-ring  347  (FIG. 7) is positioned against the guide plate  346 , and against the inner circumference of the lip  395 .  
         [0046]    [0046]FIGS. 11A to E show the outer housing  301 . The lower part of the outer housing  301  (as viewed in FIG. 11C) accommodates the upper valve housing  345  and the valve member  300 . The lower part of the outer housing  301  acts as a pressure chamber  399  for the valve assembly. Hot and cold water enter the pressure chamber via side inlets  352 ,  353 . The outer housing  301  has a barrier  350  separating its lower and upper parts. The upper valve housing  345  is seated against the lower surface of the barrier  350 . The top part of the outer housing  301  is attached to the spout  371  and any water flowing into the top part passes through and out of the spout  371 . The barrier  350  contains a series of holes  354  (FIG. 11B) through which the hot/cold water mixture may pass when the valve is in an open position. The barrier  350  also contains a separate central channel  398  which runs in a horizontal direction, and connects has a separate central outlet  357  to the spout  371 . Filtered water may flow through this channel  398 , by-passing the valve system, and exiting into the spout  371 . The outer housing  301  has a series of circumferential grooves  397  around its outer surface, which can each accommodate an O-ring in order to seal the outer housing  301  against the inside of the faucet assembly  380 . Faucets delivering hot, cold and filtered water are well known and described, fro example, in EP-A-501989  
         [0047]    [0047]FIG. 12 shows an underneath view of the faucet assembly. The faucet assembly has three inlet pipes—a hot water inlet  381 , a cold water inlet  382 , and a filtered water inlet  383 . Each inlet has a control valve  360 ,  361 ,  362  associated with it, to control the flow of water. The faucet assembly also has an outlet pipe $ 84  running through it. This outlet leads to the spray.  
         [0048]    When the spray is opened, hot and cold water which have been mixed together in the valve assembly are diverted to this outlet  384 . When the spray is closed, all the water passes out via the spout  371 . The clamp plate  363  and clamp nut  864  used to fix the faucet to a surface are also shown.  
         [0049]    [0049]FIGS. 13A to  13 E show side views and cross sectional views of the faucet assembly, and FIG. 13F shows a base view. FIG. 13C corresponds to cross section A-A on FIG. 13B, and FIG. 13D corresponds to cross section B-B. The housing or spaces for the hot  385 , cold  386  and filtered  387  water valves are shown. Each space  385 ,  386 ,  387  is connected to one of the three inlet channels  381 ,  382 ,  383 . The hot and cold water valve spaces  385 ,  386  have outlets aligned to lead to the pressure chamber of the outer housing  301 . The filtered water valve space  387  has an outlet aligned to lead to the by-pass channel  398  within the outer housing  301 .  
         [0050]    The faucet assembly also has a hole  368  into which a grub-screw may be inserted, in order to firmly attach the faucet assembly and the outer housing  301  together.  
         [0051]    [0051]FIG. 14 shows a perspective view of the valve assembly when fitted inside the faucet assembly  380 . FIG. 15 shows an enlarged perspective view of the valve assembly, in which the structures of the valve parts are more clearly shown.  
         [0052]    The paths taken by the cold water  307  and the filtered water  355  are shown. The cold water enters the system through the inlet pipe  382  in the faucet assembly  380 , and then passes through the cold water valve  361 , which controls its flow. It then enters the pressure chamber  399  via the side inlet  353 . Hot water enters the pressure chamber  399  by a second similar route, Inside the pressure chamber  399 , the hot and cold water mix together. They then exit either by the top exit, to the spout, or by the bottom exit, to the spray, depending on the position of the valve. When the spray outlet is closed, the hot/cold water mixture flows past the top piston  315  and exits to the spout via the channels  354  in the outer housing. When the spray is open, the valve member  300  is forced downwards. This is due to the fact that the bottom piston has a larger surface area than the top piston, so when both pistons have a differential pressure across them, the downward force is greater than the upward force. The upper piston  315  is forced downwards. The guide plate  346 , which is fixed to the upper piston  315 , is also forced downwards towards the upper housing  345 , compressing the O-ring  347  to provide a seal, preventing water from flowing to the spout. The seal can withstand pressures of up to 8 bar. Instead of passing through the spout, the water passes through the channels  391  in the lower piston  314 , and through the flow regulator  316  to exit via the spray unit. The flow regulator  316  prevents the water from leaving the pressure chamber  399  too quickly, so that the high pressure can be maintained inside the pressure chamber  399 . There is a certain amount of leakage around the sides of the piston, but this is minimised by having the piston and the outer housing machined to high tolerance. There is also preferably a groove in the piston to minimise the noise at higher pressures.  
         [0053]    The filtered water  355  does not pass through the valve. It enters the faucet assembly  380  via inlet pipe  383 , and its flow is controlled by faucet  362 . It then flows through a channel  356  in the faucet assembly which by-passes the valve. The spout has an inner tube  374  within it, and the filtered water passes out through this inner tube  374 . It does not, therefore mix with the hot/cold water inside the spout  371 . In this embodiment of the invention, there is no pathway by which the filtered water may exit via the spray.  
         [0054]    [0054]FIG. 16 shows a perspective view of the spout  371  connected to the faucet assembly. The spout has an end cap  375  comprising a channel through which the inner pipe  374  passes. The end cap  375  also has a series of holes  359  to allow the hot/cold water mixture to exit from the spout  371 .  
         [0055]    [0055]FIG. 17A shows a side cross sectional view of the spout. FIG. 17D shows a front view. The end cap  375  and valve assembly can be seen. FIG. 18 shows a cross sectional view of the end cap  375 , with the channels for the hot/cold water mixture, and the central channel  390  for the filtered water.