Abstract:
A valve cartridge for controlling the flow of fluid from a fluid source to a fluid outlet, the valve cartridge comprising a valve body having a first body portion and a second body portion. A valve cartridge comprising a fixed ceramic plate and a moveable ceramic plate is mounted within the body. A biasing element is disposed between the moveable ceramic plate and the second body portion for biasing the moveable ceramic plate against the fixed ceramic plate. The first and second body portions are coupled together such that a portion of the second body portion biases the fixed ceramic plate against the first valve body portion to compressibly retain the first ceramic plate there against and independently of the biasing element biasing the rotating ceramic plate against the fixed ceramic plate.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority on U.S. Provisional Application 60/173,277, filed Dec. 28, 1999. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to a valve cartridge having a valve stack-up comprising a rotating ceramic disk and a fixed ceramic disk, both with pass-through openings that are brought into alignment to control the flow of fluid through the valve; and, more particularly, to a valve cartridge having reduced tolerance variations between the stack-up elements to better control the tight seal between the ceramic disks while permitting their rotation.  
           [0004]    2. Description of the Related Art  
           [0005]    Fluid valves using ceramic valve stacks comprising a fixed ceramic disk and a rotating ceramic disk, both of which have pass-through openings that are aligned and unaligned to control the flow of fluid through the valve, are widely known and appear in various configurations, such as in-line valves, diverter valves, and hydrants, to name a few. Almost all ceramic valves comprise a “stack-up” that traditionally includes an O-ring, a fixed ceramic disk, a rotating ceramic disk, and a bearing in contact with the rotating ceramic disk. The stack-up is typically contained within a valve body, which defines the various inlets and outlets to the fluid sources.  
           [0006]    For the ceramic valve to work properly, the fixed and rotating ceramic disks must be held together in compression with a pressure (the stack-up pressure) sufficient to prevent fluid from leaking between the interface of the disks while having a rotating force less than a predetermined value. Typically, the stack-up pressure is applied by securing a valve body holding the stack-up against a compression seat, or securing a retainer to the end of the valve body as disclosed in U.S. Pat. RE 35,545. The rotating force is the force that a user must supply to the handle of the valve to rotate the rotating disk with respect to the fixed disk to turn the valve through its various operating positions. Although there is some subjectivity in the desired rotating force, the force must always remain low enough to permit the weakest of users to easily operate the valve.  
           [0007]    Striking a balance between the required stack-up pressure to prevent the ceramic valve from leaking and the desired rotating pressure is a problem for all valves using a ceramic stack-up. The problem is exacerbated in that it is very difficult to control the tolerance variations of the ceramic disks during their manufacture. The variation in the ceramic disks can vary the stack-up pressure that is required for a particular pair of ceramic disks.  
           [0008]    It is highly desirable to produce a ceramic valve that provides better control over the stack-up pressure to thereby provide better control over the stack-up pressure and the rotating pressure of the valve.  
         SUMMARY OF THE INVENTION  
         [0009]    The invention relates to a valve cartridge for controlling the flow of fluid through a fluid conduit that fludily connects a fluid source to a fluid outlet. The valve cartridge comprises first and second valve body portions. The valve body portions define a flow passage fluidly connecting the fluid source to the fluid outlet when the valve cartidge is fluidly coupled to the fluid conduit. The first and second valve body portions define a longitudinal axis.  
           [0010]    A first ceramic plate is mounted to the first body portion within the flow passage and with the longitudinal axis extending through the first plate such that the first ceramic plate is axially immovable relative to the first body portion. A second ceramic plate is mounted to the second body portion within the flow passage such that the second ceramic plate is movable along the long axis and maintained in an axially facing relationship with the first ceramic plate. Each of the first and second ceramic plates have pass-through openings and are movable to each other between a first position, where the pass-through openings are not aligned, and a fluid through the flow passage is prohibited, and a second position, where the pass-through openings are aligned to permit fluid flow through the flow passage. A biasing element is disposed between the second body portion and the second ceramic plate to bias the second ceramic plate against the first ceramic plate along the longitudinal axis.  
           [0011]    Preferably, the valve cartridge further comprises a bearing disposed between one of the first or second body portions and the corresponding first or second ceramic plates. The bearing is in abutting relationship with the corresponding first or second plate to protect the one of the first and second body portions from the relative movement of the first and second ceramic plates. The second body portion can have a bottom wall against which the second ceramic plate abuts and the bottom wall forms the bearing.  
           [0012]    At least one channel is formed in the bottom wall and the biasing element is preferably a resilient seal disposed within the at least one channel to seal the second ceramic plate relative to the second body portion and to bias the second ceramic plate against the first ceramic plate. The resilient seal is preferably an O-ring and the second body portion pass-though opening is located in the bottom wall such that it is circumscribed by the O-ring.  
           [0013]    The first body portion can comprise a top wall and an annular wall that depends from the top wall. The top wall and annular wall define a recess that is sized to receive the first ceramic plate to form a first valve seat within which the first ceramic plate is retained. The second body portion comprises a collar that defines a portion of a recess sized to receive the second ceramic plate and forming a second valve seat in which the second ceramic plate is received. The collar is preferably sized such that it abuts the first ceramic plate to bias the first ceramic seat within the first valve seat to compressibly retain the first ceramic plate against the top wall. Alternatively, the first body portion can comprise a radially extending lip that retains the first ceramic plate within the first body recess.  
           [0014]    The collar has an upper end that is approximately coterminous with an upper surface of the second ceramic plate. The depth of the second body portion recess is approximately equal to the thickness of the second ceramic plate.  
           [0015]    The collar has at least one notch formed therein and the second ceramic plate has a key extending through the notch wherein the second ceramic plate is moved between the first and second positions between the ends of the notch. Preferably, the collar comprises two diametrically opposed notches and the second ceramic plate has two diametrically opposed keys. The valve cartridge further comprises an outer collar circumscribing the second body portion having keyholes that receive the second ceramic plate key, wherein the rotation of the outer collar moves the second ceramic plate.  
           [0016]    The first body portion preferably further comprises at least one key extending into the first body portion recess and the first ceramic plate having a keyhole sized to receive the key when the first ceramic plate is received within the recess to fix the rotational position of the first ceramic plate relative to the first body portion.  
           [0017]    Preferably, the first and second ceramic plates are disks. The first and second body portions and the first and second ceramic disks can have multiple fluid openings that permit the rotation of the disks between a first position where fluid flow through the valve cartridge is prohibited, a second position where fluid flow through the valve cartridge is permitted, and a third position where fluid flow through the valve cartridge is bypassed through a filter element.  
           [0018]    The biasing device is preferably made from a resilient material. The characteristics of the resilient material are selected to control the force supplied by the bypassing element to the second ceramic plate. Preferably, the hardness and size of the resilient material are the selected and controlled characteristics. The biasing element is preferably and O-ring seal.  
           [0019]    Preferably, the first ceramic plate is located at a fixed position along the longitudinal axis independent of the position of the second ceramic plate along the longitudinal axis. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    In the drawings:  
         [0021]    [0021]FIG. 1 is an exploded view of a two-position diverter valve comprising a ceramic stack-up in accordance with the invention;  
         [0022]    [0022]FIG. 2 is a bottom view of the upper valve body;  
         [0023]    [0023]FIG. 3 is a top view of the lower valve body;  
         [0024]    [0024]FIG. 4 is a bottom view of the lower valve body;  
         [0025]    [0025]FIG. 5 is a top view of the fixed ceramic disk;  
         [0026]    [0026]FIG. 6 is a top view of the rotating ceramic disk;  
         [0027]    [0027]FIG. 7 is a bottom view of the rotating ceramic disk;  
         [0028]    [0028]FIG. 8 is a bottom view of the selection ring;  
         [0029]    [0029]FIG. 9 is a side view of the assembled valve;  
         [0030]    [0030]FIG. 10 is a longitudinal sectional view of the assembled valve of FIG. 9 and illustrates the independent mounting of the fixed disk;  
         [0031]    [0031]FIG. 11 is a partial assembly view of the fixed ceramic disk, rotating ceramic disk, and the lower valve body shown with the rotating ceramic disk in a filtered flow operational position wherein the water supply coming into the valve is diverted to a filter and returned to the valve body where it exits a spray opening;  
         [0032]    [0032]FIG. 12 illustrates the water flow path through the valve body when the rotating ceramic disk is in the filtered flow position;  
         [0033]    [0033]FIG. 13 illustrates the relative positions of the fixed ceramic disk, rotating ceramic disk, and lower valve body when the rotating ceramic disk is in a neutral position where the water input is not fluidly connected to either an external filter or directly passing through the valve;  
         [0034]    [0034]FIG. 14 illustrates the fluid flow path through the valve when the rotating ceramic disk is in the neutral position;  
         [0035]    [0035]FIG. 15 illustrates the relative positions of the fixed ceramic disk, rotating ceramic disk, and the lower valve body when the rotating ceramic disk is in a pass-through position where the fluid entering the valve passes directly through the valve body without being diverted to a filter and exiting the spout;  
         [0036]    [0036]FIG. 16 illustrates the fluid flow path through the valve when the rotating ceramic disk is in the direct flow through position; and  
         [0037]    [0037]FIG. 17 is a sectional view similar to FIG. 10 of an alternative construction of the valve cartridge with fixed disk being mounted by to the upper body portion independently of the lower body portion. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0038]    [0038]FIG. 1 illustrates a valve cartridge  10  according to the invention. The valve cartridge  10  comprises an upper valve body portion  12  and a lower valve body portion  14  that together retain a fixed ceramic disk  16  and a rotating ceramic disk  18 , whose rotational operation is controlled by a selection ring  20 . O-rings  22  seal the fixed ceramic disk  16  with respect to the upper valve body portion  12 . O-rings  24 ,  26  seal the rotating ceramic disk  18  with respect to the lower valve body portion  14 .  
         [0039]    An upper housing cover  28  and lower housing cover  30  are shaped to fit over the assembled upper valve body portion  12  and lower valve body portion  14 , respectively, to provide an aesthetic cover for the upper and lower valve body portions  12 ,  14 . Additionally, a collar  32  mounts to the upper cover  28  to aid in the connection of the valve to water supply. A nozzle  34  mounts to the lower body portion  14  to control the valve flow of fluid from the valve cartridge. The covers  28 ,  30 , collar  32 , and nozzle  34  are not germane to the function of the valve  10  and will not be described in greater detail.  
         [0040]    The various functional components of the valve cartridge  10  will now be described in greater detail. Referring to FIGS. 1 and 2, the upper valve body portion  12  comprises a top wall  40  having a depending annular wall  42 , which is interrupted by opposing notches  44 . The top wall  40  and the annular wall  42  define a recess  45  that forms a seat for the fixed disk  16 . Keys  46  extend away from the annular wall  42 . A tubular inlet  48  (FIG. 16) extends upwardly from the top wall  40  and defines an inlet chamber that is in fluid communication with a fluid source when the valve is assembled. A filter inlet  50  extends horizontally relative to the top wall  40 . Similarly, a filter outlet  52  extends horizontally away from the top wall  40 . The fluid inlet  46 , filter inlet  50 , and filter outlet  52  are all fluidly connected to the interior of the upper valve body portion  12  through pass-through openings  54 ,  56 ,  58 , respectively, which are surrounded by annular channels  60 ,  62 , and  64 , which are sized to receive the O-rings  22 .  
         [0041]    Referring to FIGS. 1, 3, and  4 , the lower valve body portion  14  comprises a bottom wall  70 , having an upwardly extending peripheral wall  72  interrupted by diametrically opposing notches  74 . The inner surface of the top wall  70  and peripheral wall  72  form a recess  73  that forms a seat for the rotatable disk  18 . A guide collar  76  extends upwardly from the peripheral wall  72  and has a slightly smaller radius than the peripheral wall  72 .  
         [0042]    A spout opening  78  is axially located in the bottom wall  70  and is surrounded by an O-ring groove  80 . A filtered output opening  82  also passes through the bottom wall  70  and is located in a filtered fluid outlet channel  84  formed in the bottom wall  70 , which is concentrically oriented with respect to the O-ring groove  80  in the spout opening  78 . Also formed in the bottom wall  70  is an O-ring groove  86  concentrically located outside the filtered fluid outlet channel  84  and interior of the peripheral wall  72 .  
         [0043]    The O-ring groove  80 , outlet channel  84 , and O-ring groove  86  effectively define circular portions or rings  81 ,  83 , and  85 , respectively, in the bottom wall  70 . The tops of these rings define the bottom wall upper surface and form a bearing against which the rotatable disk  18  abuts when the valve is assembled.  
         [0044]    A filtered outlet spout  88  extends away from the exterior side of the bottom wall  70  along with a nozzle mounting collar  90 . The nozzle-mounting collar  90  is threaded, permitting the nozzle  34  to be threaded onto the nozzle-mounting collar to mount the nozzle to the lower body portion.  
         [0045]    Referring to FIGS. 1 and 5, the fixed ceramic disk  16  is generally circular with diametrically opposing keyholes  94  extending into the edge of the disk  16 . The key holes  94  are sized to receive the keys  46  of the upper valve body portion  12  to fix the relative position of the fixed ceramic disk  16  with respect to the upper valve body portion  12 . Multiple pass-through openings  96 ,  98 , and  100  extend through the fixed ceramic disk  16 . The pass-through openings  96 ,  98 , and  100  correspond to the pass-through openings  54 ,  56 , and  64  of the upper valve body portion  12 . The fixed ceramic disk  16  is mounted to the upper valve body portion  12  and permits the flow of fluid from the pass-through openings of the upper valve body portion  12  to also pass through the corresponding openings in the fixed ceramic disk  16 .  
         [0046]    Referring to FIGS. 1, 6 and  7 , the rotating ceramic disk  18  has a generally circular shape from which extend keys  110 , which are sized to be received within the notches  44 ,  74  of the upper and lower valve body portions  12 ,  14  when the valve is assembled. The rotating ceramic disk is of a smaller diameter than the fixed ceramic disk. An elongated blind opening  112  is located on the upper surface of the rotating ceramic disk  18  and extends slightly radially outwardly from the center of the rotating ceramic disk  18 . The elongated opening  112  is used to establish fluid communication between the fluid inlet opening  96  and filter inlet opening  98  of the fixed ceramic disk  18 .  
         [0047]    A pass-through opening  114  in combination with an arcuate blind opening portion  116  is also provided on the upper surface of the rotating ceramic disk  18 . The pass-through opening  114  fluidly connects the filter outlet pass-through opening  100  of the fixed ceramic disk to the filtered fluid outlet channel  84  of the lower valve body portion  14 . The corresponding arcuate blind portion  116  aids in keeping the pass-through opening  114  in fluid communication with the filter outlet pass-through opening  104  for a predetermined rotational range of the rotating ceramic disk  18 .  
         [0048]    A pass-through opening  118  in combination with an arcuate blind opening  120  is provided on the upper surface of the rotating ceramic disk  18  and establishes fluid communication between the fluid inlet pass-through opening  96  of the fixed ceramic disk  16  and the spout opening  78  of the lower valve body portion  14 . The arcuate blind opening  120  is shaped to maintain fluid communication between the fluid source pass-through opening  96  of the fixed ceramic disk  16  and the pass-through opening  118  of the rotating ceramic disk  18  through a predetermined rotational range of the rotating ceramic disk  18 .  
         [0049]    Referring to FIGS. 1 and 8, the selection ring  20  comprises an outer collar  130  and an inwardly directed annular lip  132  in which are formed diametrically opposing key holes  134 , sized to receive the keys  110  of the rotating ceramic disk  18  when the valve is assembled.  
         [0050]    Referring to FIGS. 1, 9 and  10 , the assembly of the valve  10  will be described in detail. Initially, it should be noted that the particular sequence of the assembly as described here is only one of the many possible combinations for assembling the valve. Many of the various ways to assemble the valve are equally preferred. Therefore, the described assembly of the valve is only meant to better describe the interfitting of the various valve elements and is not meant to limit the valve assembly to the described sequence.  
         [0051]    The assembly begins by creating a lower body portion sub-assembly. The O-rings  24 ,  26  are inserted into their corresponding O-ring grooves  80 ,  86  of the lower valve body portion  14 . The rotating disk  18  is placed on the bearing formed by the upper surface of the rings  81 ,  83 ,  85  of the bottom wall  70  so that the rotating ceramic disk keys  110  lie between the notches  74  of the peripheral wall  72 . The selection ring  20  is oriented so that the key holes  134  align with the keys  110  on the rotating ceramic disk and is pressed onto the lower valve body  14  so that the guide cover  76  passes through the lip  132  of the selection ring  20  and the keys  110  seat within the key holes  134 . The lower valve body portion  14 , rotating ceramic disk  18  and selection ring  20  can be handled as a subassembly by merely compressively holding together the lower valve body portion  14  and the selection ring  20 .  
         [0052]    Once the lower valve body portion subassembly  14  is completed, the O-rings  22  are placed within the corresponding O-ring grooves  60 ,  62 , and  64  and the upper valve body portion  12  to begin the upper valve body portion subassembly. The fixed ceramic disk  16  is oriented relative to the upper valve body portion  12  so that the key holes  94  of the fixed ceramic disk  16  align with the keys  46  of the upper valve body portion  12 . The fixed ceramic disk  16  is pressed into the annular wall  42  of the upper valve body portion  12  until the keys  46  seat within the key holes  94 , completing the upper valve body portion  12  subassembly.  
         [0053]    The upper and lower valve body portion subassemblies are brought together by inserting the guide collar  76  of the lower valve body portion  14  into the interior of the annular wall  42  of the upper valve body portion  12 . The guide collar  76  abuts the bottom surface of the fixed ceramic disk  16  and compressively retains the fixed ceramic disk therebetween. As the lower body  14  is interfitted with the upper body portion  12 , the O-rings  24 ,  26  and possibly the upper surface of the lower body portion press against the lower surface of the rotating ceramic disk  18  to compress the upper surface of the rotating ceramic disk  18  against the bottom surface of the fixed ceramic disk  16  to apply the stack-up pressure between the ceramic disks. The upper and lower valve body portions  12 ,  14  are then sonically welded together or attached by any other suitable means.  
         [0054]    When assembled, the valve cartridge  10  has a longitudinal axis A. The axis A preferably passes through the center point of the ceramic disks.  
         [0055]    The height of the guide collar  76  is such that the fixed ceramic disk  16  is compressively retained between the guide collar  76  and the top wall  40  just as or slightly before the peripheral wall  72  of the lower valve body portion  14  abuts the peripheral wall  42  of the upper valve body portion. The depth of the recess  73  is substantially equal to or greater than the thickness of the rotating ceramic disk  18 . The structural relationship between the collar  76  and the recess  73  permits the mounting of the fixed ceramic disk to the upper valve body portion at fixed location relative to the upper valve body portion and the axis A, while preventing the movement of the fixed disk along the axis A.  
         [0056]    The benefit of such a fixed mounting of the fixed disk to the upper body portion such that it is not moveable relative to the axis A is that the tolerance variation attributable to the fixed disk is controlled without reliance on the biasing force of the O-ring. In other words, the tolerance variation attributable to variations in the thickness of the fixed disk is controlled by the lower body portion pressing the upper face of the fixed ceramic disk against the top wall of the upper body portion. In previous valve cartridges, the biasing force associated with the O-ring would have to compensate for the tolerance variation in both the fixed and rotation ceramic disks, which lead to higher than desired forces needed to rotate the rotating disk.  
         [0057]    To complete the assembly of the valve  10 , the collar  32  is mounted to the upper body portion  12 , which is positioned over the upper valve body portion  12  and affixed thereto preferably by sonic welding or adhesive. The lower body cover  30  is then slidably mounted over the filter nozzle  88  and collar  90  and affixed to the lower valve body portion  14 , preferably sonic welding or adhesive. The nozzle  34  is positioned over the collar  90  and affixed thereto in a manner similar to the upper and lower covers  28 ,  30 .  
         [0058]    As best seen in FIG. 10, one important advantage of the valve cartridge  10 , according to the invention, is that the valve stack-up comprises only the rotating ceramic disk  18  and the O-rings  24 ,  26 . The fixed ceramic disk  16  is effectively taken out of the stack-up since it is compressively retained between the guide collar  76  and the lower surface of the bottom wall  40  independent of the mounting of the rotating disk. Thus, the compressive force applied by the lower body portion and O-rings to the rotating disk need only account for the tolerance variation in the rotating disk, instead of both of the fixed and rotating disk as in the prior art valve cartridges.  
         [0059]    The compressive force applied by the O-rings is a function of the resiliency of the O-rings and the degree to which they are compressed up the mounting of the lower body portion to the upper body portion. Since, in the preferred design, the insertion of the lower body portion relative to the upper body portion is limited by the annular collar abutting the fixed disk, the axial compression of the O-rings is so limited. The biasing force associated by the axial compression is attributable to the resiliency of the material forming the O-rings. With these factors in mind, the cross-section size of the O-rings can be selected to control the amount of material to be compressed and the hardness of the material can be selected to control the force that is applied by the compressed O-ring to the rotating ceramic disk. By controlling these characteristics of the O-rings, and any other biasing element, the force applied by the O-rings against the rotating ceramic disk can be controlled, which permits control of the stack-up pressure, which is the O-ring force acting over the area of the rotating ceramic disk.  
         [0060]    In essence, the O-rings function like a spring. The O-rings can be replaced by any other suitable biasing element, such as a spring. The O-ring is preferred because it performs the dual function of sealing the rotating ceramic disk relative to the lower body portion and applying the compressive force.  
         [0061]    An additional advantage of the stack-up of the valve cartridge  10  is that the bearing surface, to the extent it is needed, is integrated with the lower valve body  14 , effectively eliminating it&#39;s tolerance losses from the stack up. The bearing function of the valve cartridge  10  is performed by the portion of the bottom wall  70  not forming a part of the O-ring grooves  80 ,  86  and the filter fluid outlet channel  84 . Thus, any tolerance variation attributable to the bearing does not need to be accounted for by the stack-up pressure applied by the lower body portion and the O-ring, unlike the prior art valve cartridges.  
         [0062]    Therefore, the stack-up pressure as applied by the O-rings as they are compressed against the bottom wall  70  to seal the fixed and rotating ceramic disks  16  and  18  need only be concerned about the tolerance variances associated with the rotating ceramic disk  18  and not the combined tolerance losses of the rotating ceramic disk, fixed ceramic disk, and bearing, as in prior art valve cartridges. Moreover, since only the tolerance variation of the rotating ceramic disk need be accounted for in the stack-up pressure, the characteristics of the material for the biasing element, such as the O-ring, can be more accurately selected. Typically, these characteristics, in the case of an O-ring, are the hardness and the cross-sectional area and shape. These characteristics are selected such that the force applied to the rotating ceramic disk is such that a seal is maintained between the rotating and fixed disk. The harder (less resilient) the material and the greater the cross-sectional area the greater will be the force transferred from lower body portion to the rotating ceramic disk.  
         [0063]    The major operational portions of the valve  10  will be described with respect to FIGS.  11 - 16 . FIGS. 11 and 12 illustrate the relative positions of the fixed ceramic disk  16 , rotating ceramic disk  18 , and lower valve body portion  14  when the rotating ceramic disk  18  is in the filtered output position along with the fluid flow path through the valve  10 . For illustrative purposes, FIG. 11 shows the lower valve body portion  14  and its corresponding spout opening  78 , filtered output  82 , and filter fluid outlet channel  84  in phantom. The water inlet pass-through opening  96 , filter inlet pass-through opening  98 , and filter output pass-through opening  100  of the fixed ceramic disk along with the elongated blind opening  112 , filter pass-through opening  114  and arcuate blind opening  116 , and fluid source through opening  118  and arcuate blind opening  120  are illustrated as solid lines even though the pass-through openings  96 ,  98 ,  100  of the fixed ceramic disk  16  are positioned above the rotating ceramic disk  18 .  
         [0064]    In the filtered output position, the rotating ceramic disk  18  is rotated counterclockwise as seen in FIG. 11 looking from the upper valve body portion  12  down to the lower valve body  14  until the keys  110  abut the peripheral wall  72 . In this position, the elongated blind opening  112  of the rotating ceramic disk  18  fluidly connects the fluid source inlet pass-through opening  96  to the filter inlet pass-through opening  98 , diverting the fluid supply entering the fluid inlet  48  of the upper valve body portion  12  to the filter inlet  50 . The filter pass-through opening  114  and its corresponding arcuate blind opening  116  are fluidly connected to the filter pass-through opening  100  and the fixed ceramic disk  16 , permitting the output from the filter to pass through the filter outlet  52 , through the ceramic disks  16 ,  18  into the fluid channel  84  of the lower valve body  14  where the filtered output exits through the filtered output  82  and its corresponding filter nozzle  88 .  
         [0065]    [0065]FIGS. 13 and 14 illustrate the relative position of the fixed ceramic disk  16 , rotating ceramic disk  18 , and lower valve body portion  14 , along with the fluid flow path through the valve cartridge  10  when the valve is in the neutral or off position. In the neutral position, the rotating ceramic disk  18  is rotated through approximately 30 degrees clockwise (as seen in FIG. 13) from the filtered output position of FIG. 11. In the neutral position, the elongated blind opening  112  is no longer in fluid communication with either the source inlet through opening  96  or filter inlet through opening  98  of the fixed ceramic disk  16 , preventing the flow of fluid from the fluid source to the filter. However, the filter pass-through opening  114  and its corresponding arcuate blind opening  116  are still in fluid communication with the filter outlet pass-through opening  100  of the fixed ceramic disk  16  and the filter fluid outlet channel  84 , permitting the draining of any pressurized fluid from the filter. It is important for the longevity of the the filter device, that the fluid source is shut off to the filter prior to the shutting off of the flow from the filter, which effectively permits the draining of any pressurized fluid from the filter and reducing the likelihood that a back pressure can be created in the fluid system that might adversely impact the seals of the filter and the valve.  
         [0066]    [0066]FIGS. 15 and 16 illustrate a straight through output position of the valve cartridge  10 . FIG. 15 and  16  illustrate the relationship of the fixed ceramic disk  16 , rotating ceramic disk  18 , and lower valve body portion  14  along with the corresponding fluid path through the valve cartridge  10 . In the flow through position, the elongated blind opening  112  and filter pass-through opening  114  and its corresponding arcuate blind opening  116  are no longer in fluid communication with any pass-through openings of the fixed ceramic disk  16 . However, the fluid source through opening  118  and its corresponding arcuate blind opening  120  are in fluid communication with the fluid source pass-through opening  96  with a fixed ceramic disk  16  and the spout opening  78  and the lower valve body portion  14 , permitting the flow of fluid from the fluid inlet  48  through the valve cartridge  16 ,  18  and out through the spout opening  78  and nozzle  34 .  
         [0067]    Preferably, the rotating ceramic disk  18  rotates through approximately  60 . If the entire rotational range is thought of in terms of −30° to 30° the neutral position occurs at 0°, the filtered output at −30° and the pass-through output at 30°. The rotating ceramic disk is rotated by turning the selection ring  20 .  
         [0068]    [0068]FIG. 17 illustrates an alternative construction for the valve cartridge  10 . The only difference between the alternative construction of FIG. 17 and the valve cartridge of FIGS.  1 - 16  is in the manner in which the fixed ceramic disk is mounted to the upper body portion. Therefore, like numerals will be used to identify like parts in both constructions.  
         [0069]    In the alternative construction of FIG. 17, the upper body portion annular wall  42  comprises an inwardly directed radial lip  43  that extends over the fixed ceramic disk  16  to compressively retain the fixed ceramic disk within the recess  45 . The radial lip  43  can be formed in many different ways. For example, the fixed ceramic disk can be in-molded with the upper body portion. The radial lip can be a staked or bent portion of the annular wall  42 .  
         [0070]    Since the radial lip  43  performs the function of the collar  76 , the lower body portion need not have the collar  76  of the first embodiment. In all other aspects the alternative constructions are identical.  
         [0071]    While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.