Abstract:
A water purifying unit having a unique construction which enables it to be easily manufactured, assembled and serviced. The construction of the unit is such that it can with stand increased water pressure levels and is thus less prone to damage from water hammer.

Description:
RELATED APPLICATION INFORMATION  
         [0001]    This application claims priority under 35 U.S.C. §119(e) to Australian patent application number PR2102, filed Dec. 13,  2000 .  
         FIELD OF THE INVENTION  
         [0002]    The present invention relates to a water purifying unit and more particularly to a water purifying unit that can be installed for domestic use.  
         BACKGROUND OF THE INVENTION  
         [0003]    Over recent years the demand for high quality drinking water has greatly increased. Consumers have become more health conscious and more particular about the quality of the water that they drink. Although the water available in most people&#39;s homes would meet all of the standard water safety requirements, the taste and appearance of the water may not meet the consumer&#39;s expectations.  
           [0004]    Many consumers have therefore resorted to installing water purifying units to purify their drinking water.  
           [0005]    There are a number of different units available in the market place and the quality of these units varies. Furthermore, the expected lifespan of these units and the quality of the water produced from the units also varies greatly.  
           [0006]    The present invention seeks to provide an improved water purifying unit.  
         SUMMARY OF THE INVENTION  
         [0007]    According to a first aspect of the present invention there is provided a water purifying unit including a head having a first and a second chamber, an inlet port, an outlet port and a transfer port between the first and second chambers, each of the first and second chambers being arranged so that a sump can be removably secured thereto, a diverter mounted within each of said first and second chambers, said diverter dividing its respective chamber into an inlet zone and an outlet zone, each said diverter further being arranged so that a purifying cartridge can be attached thereto and located within the associated sump, and wherein the head is arranged so that water can enter the head, pass into the inlet zone of the first chamber, through the associated cartridge and into the outlet zone of the first chamber, through the transfer port located in the head, into the inlet zone of the second chamber, through the associated purifying cartridge into the outlet zone of the second chamber and out through the outlet port of the head.  
           [0008]    The head is preferably molded as a single unit from a plastics material. The preferred material is an ABS plastics. ABS plastics are a group of plastic materials based on blended copolymers of styrene-acrylo-nitrile and butadiene-acrylonitrile and on graft interpolymers of styrene and acrylonitrile with polybutadiene. After molding of the head the inlet port, transfer port and outlet port are formed in the head preferably by a single post molding drilling operation.  
           [0009]    Each diverter is preferably molded from a plastics material. The preferred material is preferably an ABS plastics. The diverter is preferably shaped so that it can be pressed into its respective chamber and adhered thereto using an appropriate adhesive.  
           [0010]    The inner wall of each chamber and the associated diverter preferably include a complimentary indentation and protrusion. This complimentary indentation and protrusion serve to properly position the diverter within its respective chamber during assembly of the unit. The inner wall of each chamber and the associated diverter may include alternative means for aiding the proper positioning of the diverter in the associated chamber.  
           [0011]    The inner wall of each chamber and its associated diverter are configured so that when they are assembled together they define there between the inlet zone and the outlet zone.  
           [0012]    Each diverter is configured so that a water purifying cartridge can be attached thereto. Preferably, the diverter and cartridge have complimentary bayonet type fitting means to enable the cartridge to be secured to the diverter.  
           [0013]    In a preferred form, the diverter includes a centrally located bayonet aperture and the cartridge includes a bayonet fitting at an upper end. The bayonet fitting of the cartridge being arranged to pass through the bayonet aperture whereafter the cartridge can be rotated to positively locate the bayonet fitting within the diverter.  
           [0014]    A double O-ring seal is preferably provided between the diverter and the upper end of the cartridge to prevent water leakage there between.  
           [0015]    Each sump is preferably molded from a plastics material. The preferred material is an ABS plastics.  
           [0016]    Each sump is preferably arranged to be attached to the head by a threaded connection. The upper inner wall of the sump preferably includes a screw thread arranged to threadedly engage with a complimentary screw thread on a lower end portion of the chamber to which it is to be secured.  
           [0017]    An O-ring seal is provided between the lower end of each chamber and the associated sump to prevent water leakage.  
           [0018]    The sump is preferably configured so that a cartridge can be secured to the respective diverter and then the sump connected to the head about the cartridge. Sufficient clearance is provided between the inner wall of the sump and the outer surface of the cartridge to enable water to flow into the sump and through the cartridge.  
           [0019]    The cartridge preferably includes an upper end cap, a lower end cap, a fluid pathway and a filter member.  
           [0020]    The cartridge is preferably substantially cylindrical in shape.  
           [0021]    The fluid pathway of the cartridge enables water that has passed through the filter member of the cartridge to pass into the outlet zone of the chamber. Spaced peripherally about the lower end cap of the cartridge are at least a pair of protrusions. The protrusions being arranged to prevent side to side movement of a lower end of the cartridge when high water pressure loads are applied to the cartridge. The protrusions are sized so that the cartridge can fit within the sump while still preventing excessive side-to-side movement of the cartridge under load conditions.  
           [0022]    Preferably, the protrusions take the form of triangular shaped wings which extend outwardly of the cartridge.  
           [0023]    In a preferred form, the head includes means for enabling the unit to be attached to a surface such as a sidewall of a cupboard.  
           [0024]    A decorative cover may be arranged to fit on the head to provide an improved aesthetic appearance to the unit.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:  
         [0026]    [0026]FIG. 1 is a perspective view of a purifying unit in accordance with an embodiment of the invention.  
         [0027]    [0027]FIG. 2 is an assembly view of the purifying unit shown in FIG. 1.  
         [0028]    [0028]FIG. 3 is a vertical cross-sectional view of the purifying unit shown in FIG. 1.  
         [0029]    [0029]FIG. 4 is a rear view of the water purifying unit as shown in FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]    A water purifying unit  10  in accordance with an embodiment of the invention is shown in FIG. 1. The water purifying unit  10  includes a head  12  having first and second open ended chambers  14 ,  16  formed therein. A sump  18  is arranged to be removably secured to the lower end  14   a,    16   a  of each of the first and second chambers  14 ,  16 . Positioned within the respective chambers  14 ,  16  and sumps  18  are a diverter  20  and filter cartridge  22 . As will be described in more detail below and as illustrated in FIGS. 2 and 3, a diverter  20  is arranged to be permanently mounted within the upper end of each of the first and second chambers  14 ,  16 . A filter cartridge  22  is in turn arranged to be removably connected to an associated diverter  20 . A decorative cover  24  is snap fitted to the upper side  12   a  of the head  12 .  
         [0031]    The components of the water purifying unit  10  are best illustrated in FIGS. 2 and 3. As shown in these figures, the head  12  includes an inlet port  26 , an outlet  28  and a transfer port  30  which extends between the first and second chambers  14 ,  16 . Each of the first and second chambers  14 ,  16  has a substantially cylindrical configuration and includes a chamber side wall  32  and a chamber top wall  34 . The transition between the chamber side wall  32  and the chamber top wall  34  is smooth with a large radius of curvature.  
         [0032]    Located within each of the first and second chambers  14 ,  16  is the diverter  20 . The diverter  20  includes an upper wall portion  20   a  which is shaped so that it can be located with a press fit within its associated chamber  14 ,  16 . The diverter  20  includes an indentation  20   b  which when located within its associated chamber  14 ,  16  is arranged to fit over a complimentary shaped protrusion  36  formed on the chamber top wall  34 . The complimentary indentation  20   b  and protrusion  36  serve to properly position the diverter  20  within its respective chamber  14 , 16 .  
         [0033]    When the diverter  20  is properly located within its associated chamber  14 ,  16  it divides its associated chamber  14 ,  16  into an inlet zone  38  and an outlet zone  40 .  
         [0034]    The diverter  20  includes a centrally located bayonet aperture  42  which is arranged to receive a bayonet fitting  44  which is formed as part of an upper end cap  46  of the filter cartridge  22 . The bayonet aperture  42  is arranged so that the bayonet fitting  44  can pass there through and subsequently be rotated so as to positively locate the bayonet fitting  44  of the filter cartridge  22  within the diverter  20 .  
         [0035]    Once a filter cartridge  22  has been connected to the diverter  20 , a sump  18  is connected to the associated chamber  14 ,  16 . The sump  18  is connected to the associated chamber  14 ,  16  by means of a threaded connection. As is best illustrated in FIG. 3, an upper inner side wall  18   a  of the sump  18  includes a threaded portion  18   b  which is arranged to engage with a threaded portion formed on the periphery of the lower portion of the side wall  52 . The sump  18  is configured so that the transition between the inner side wall  18   a  of the sump  18  and the inner bottom wall  18   b  is smooth with a large radius of curvature.  
         [0036]    To ensure water tightness of the purifying unit  10  an O-ring seal  55  is located between the lower edge of the side wall  52  of each of the chambers  14 ,  16  and the associated sump  18 . In addition, a double O-ring seal  56  is provided between the diverter  20  and the bayonet fitting  44  of the filter cartridge  22 . As best illustrated in FIG. 3, the filter cartridge  22  includes a filter element  58  which is located between the upper end cap  46  and a lower end cap  60 . A fluid pathway  62  is located substantially centrally of the filter element  58  so that water passing through the filter element  58  can enter the fluid pathway  62  and be driven upwardly in a manner described in more detail subsequently.  
         [0037]    The cartridge  22  is sized so that when it is connected to the diverter  20  and the associated sump  18  is attached to the head  12 , there is a clearance space  64  between the inner side wall  18 a of the sump  18  and the outer periphery of the filter cartridge  22 .  
         [0038]    In use, the filter unit  10  is connected to a water supply so that water can flow through the unit  10  and be purified. Water passes through the inlet port  26  and into the inlet zone  30  of the first chamber  14 . The water then flows through the clearance space  64 . Once the sump  18  is full, the water is caused to flow through the filter element  58  and into the fluid pathway  62 . The water then passes up the fluid pathway  62  through the upper end of the bayonet fitting  44  and into the outlet zone  34  of the first chamber  14 . The water then passes through the transfer port  30  which connects the first and second chambers  14 ,  16 . The previously described cycle is then repeated within the second chamber  16 . That is, the water passes into the inlet zone  38  of the second chamber, into the clearance space  64 , through the filter element  58 , up the fluid path  62  and into the outlet zone  40  of the second chamber  16 . The purified water then passes through the outlet port  28  of the purifying unit  10  whereafter it passes into pipework connected to a conventional plumbing outlet.  
         [0039]    As best illustrated in FIG. 2, located peripherally about the lower end cap  60  are a series of protrusions  70 . The protrusions  70  take the form of triangular shaped wings which extend outwardly of the filter cartridge  22 . The purpose of the protrusions  70  is to prevent excessive side to side movement of the filter cartridge  22  under high water load conditions. Without the protrusions  70  the filter cartridge  22  under high load conditions may be jarred back and forth in a side to side motion. As the filter cartridge  22  is only held in position by the location of the bayonet fitting  44  within the bayonet aperture  42 , side to side movement of the cartridge  22  may result in the bayonet fitting  44  becoming damaged and may in fact cause the bayonet fitting  44  to snap off so that the cartridge  22  is disconnected. The inclusion of the protrusions  70  substantially reduces if not totally prevents side to side movement of the filter cartridge  22  which may result from high water load forces. Such forces often occur if there is water hammer within the pipe work to which the purifying unit  10  is connected.  
         [0040]    The head  12  is molded as a single unit from a plastics material. The preferred material is an ABS plastics. After molding of the head  12  the inlet port  26 , transfer port  30  and outlet port  38  are formed by a single post molding drilling operation. Basically, a drill of appropriate size is bored through the head  12  to form the inlet, transfer and outlet ports  26 ,  30 ,  28 . The inlet and outlet ports  26 ,  28  are then threaded so that they can be readily connected to the water pipework of the home etc.  
         [0041]    After the ports  26 ,  30 ,  28  are formed in the head  12 , a diverter  20  is located within each of the first and second chambers  14 ,  16 . The diverter  20  is molded from a plastics material and is preferably made from an ABS plastics. The configuration of the diverter  20  and the inner walls  32 ,  34  of the chambers  14 ,  16  is such as to enable the diverter  20  to be located within the associated chamber  14 ,  16  with a press fit. An appropriate adhesive is used to permanently locate the diverter  20  within the associated chamber  14 ,  16 .  
         [0042]    Each sump  18  is molded from a plastics material. The preferred material for each of the sumps  18  is an ABS plastics. The materials from which the head  12 , sump  18  and diverter  20  are made have been selected so as to ensure adequate strength of these components and to reduce the creep of these components. In this way, any variation in the structure of the various components due to creep is minimised and therefore the ultimate fit between the components will be maintained after many hours of continuous use.  
         [0043]    As shown in FIG. 4, the head  12  also includes an attachment surface  80  which includes a pair of apertures  82 . These apertures  82  are arranged to fit over a protruding screw which is connected to a wall, such as a sidewall to a cupboard. In this manner, the purifying unit  10  can be mounted against the side wall of a cupboard or other wall.  
         [0044]    As stated previously, a decorative cover  24  is located on the upper side  12   a  of the head  12 . The cover  24  is provided to improve the aesthetic appearance of the purifying unit  10 .  
         [0045]    A purifying unit  10  in accordance with an embodiment of the invention has many advantages over prior art devices. For example, in previous devices the head and chambers were made from a number of different components which were assembled together in a cumbersome and time consuming manner. In addition, the two chambers had to be connected by a connection in the form of a nipple which was manually positioned and attached between the two sumps.  
         [0046]    It will also be appreciated by those skilled in the art that in prior art devices the filter cartridge was positioned within the sump between upper and lower seats. When the sump was tightened to the head the seal between the upper and lower seats and the ends of the cartridge was perfected. However, over time and with creep of the various components of such prior art units, the integrity of the seal was lost and thus the effectiveness of the purifying unit decreased. The configuration of the purifying unit in accordance with an embodiment of the invention eliminates this problem because of the use of the bayonet type fitting to secure the filter cartridge to the head. Thus, any creep within the system will not affect the effectiveness of the filtering system.  
         [0047]    It will also be appreciated that the large smooth curves formed between the side and bottom wall of the sump  18 , together with the materials from which the various components of the purifying unit  10  are made, result in a purifying unit  10  that can be used under increased water pressure levels. For example, conventional water purifying units are normally considered to be able to safely operate with static water pressure levels of 500 psi. However, it is envisaged that a purifying unit  10  in accordance with an embodiment of this invention will be able to withstand static water pressure levels up to 750 psi. It is also envisaged that a water purifying unit  1  in accordance with an embodiment of the invention will be able to withstand water hammer pressures between 1500 and 1600 psi.  
         [0048]    A water purifying unit  10  made in accordance with an embodiment of the invention will be easier to manufacture because of the reduced number of components, will be able to withstand higher static water pressure levels and will maintain its water purifying capabilities despite any creep in the component parts thereof. All of these advantages are achieved while still maintaining a construction which can be easily disassembled to enable changeover of the filter cartridges  22 . Furthermore, the filter cartridges  22  can be easily connected to the associated diverter  20  simply by passing the bayonet fitting  44  through the bayonet aperture  42  and rotating the cartridge  22 . The positive connection between the filter cartridge  22  and the bayonet aperture  42  means that the user can readily identify when the filters cartridge  22  is properly located.  
         [0049]    The embodiment has been described by way of example only and modifications within the spirit and scope of the invention are envisaged.