Abstract:
A hot water filter ( 30 ) for a dishwasher ( 10 ) having a base ( 34 ) connected to a hot water line ( 28 ) to allow water to be filtered prior to introduction into the dishwasher washing compartment, a filter element ( 42 ) and a housing element ( 40 ) for attaching to the base ( 34 ) and enclosing the filter element ( 42 ). The filter element ( 42 ) includes one or more stages or layers ( 70, 72, 74, 76 ) to filter the water. In one embodiment, the filter element ( 42 ) has a cation resin layer ( 74 ), a carbon layer ( 72 ) and one or more water permeable layers ( 70, 76 ).

Description:
[0001]    This application claims benefit to U.S. Provisional Patent Application No. 60/986,618, filed Nov. 9, 2007; U.S. Provisional Patent Application No. 60/922,900, filed Apr. 11, 2007; U.S. Provisional Patent Application No. 60/922,690, filed Apr. 9, 2007; U.S. Provisional Patent Application No. 60/918,858, filed Mar. 19, 2007; and U.S. Provisional Patent Application No. 60/905,409, filed Mar. 7, 2007. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to hot water line filters for dishwashers. 
       BACKGROUND ART 
       [0003]    While electronic dishwashers provide a means to readily clean dishes with less manual labor, many dishwashers leave spots, films or other residue on the dishes after completion. This can lead to having to manually or otherwise rewash the dishes—thereby eliminating the benefits of an automatic dishwasher—serving dishes that give the appearance of being unclean or dirty. 
         [0004]    While most people assume that faulty or outdated dishwashers cause spots and films on dishes, Applicants have determined that most blemishes are caused by minerals (e.g., calcium or magnesium) and other sediments in the water itself. Accordingly, in addition to “dirty” dishes, continued use of such water can lead to, among other things, buildup in the mechanical parts of the dishwasher, thereby causing damage to the dishwasher or lowering the length of the dishwasher&#39;s life. 
       DISCLOSURE OF THE INVENTION 
       [0005]    The present invention is an improvement over the prior dishwasher filtering systems in the way that the hot water filter filters water going into the dishwasher. In one embodiment, a base having an inlet and an outlet is positioned within an opening in the dishwasher to allow hot water to travel through the inlet and out the outlet after being filtered. In particular, the inlet leads into the inside of a housing member  40  that is sealingly attached to the base and which encloses a filter element. 
         [0006]    The filter element comprises one or more layers or phases to filter the hot water prior to its introduction into the dishwasher washing compartment. In order to reduce film and sediment like sand and rust, the water may first pass through a water permeable layer such as polypropylene wound fibers. An activated carbon phase or layer may be used to, among other things, improve the taste and odor of the water. The filter element also includes a cation resin layer or phase to filtrate and remove calcium and magnesium from hard water, while replacing it with sodium. This will allow the consumer to use less dishwashing detergent because removal of the calcium and magnesium from the water allows the detergent to better mix with the softened water. Another water permeable layer such as polypropylene wound fibers may be located towards the outlet end of the filter element. 
         [0007]    It is therefore an object of the present invention to provide a new system and method for introducing clean water into a dishwasher. 
         [0008]    Another object of the present invention is to provide a new system and method for cutting down on chlorine and mineral deposits in dishwashers. 
         [0009]    It is yet another object of the present invention to provide a new system and method for filtering out rust and sediments from dishwasher water. 
         [0010]    Still yet another object of the present invention is to provide a system and method for extending the life of a dishwasher. 
         [0011]    Another object of the present invention is to provide a system and method for removing taste and odor from dishwasher water. 
         [0012]    Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The design of the system can be better understood by following the description of the drawings set forth herein. A brief description of each figure is included here. 
           [0014]      FIG. 1  is a front elevated view of one embodiment of a dishwasher utilizing a hot water line filter of the present invention. 
           [0015]      FIG. 2  is a perspective view of one embodiment of the hot water line filter of the present invention. 
           [0016]      FIG. 3  is a perspective inverted and exploded view of the hot water line filter of  FIG. 2 . 
           [0017]      FIG. 4  is a cross-sectional view of the hot water line filter of  FIG. 2  taken along line  4 - 4 , with arrows showing the directional flow of water through the filter. 
           [0018]      FIG. 5  is a top perspective view of one embodiment of the base of the filter. 
           [0019]      FIG. 6  is a bottom plan view of the housing of the filter of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail several specific embodiments, with the understanding that the present disclosure is to be considered merely an exemplification of the principles of the invention and the application is limited only to the appended claims. 
         [0021]    Referring to  FIG. 1 , one embodiment of a dishwasher is shown. The undercarriage  12  supporting a frame  14  having a door  16  that is hingedly attached to the frame to permit access to the washing compartment of the dishwasher  10 . A control panel  18  having a series of buttons  20  may be located at the top of the frame  14  to control the operation of the dishwasher  10 . It is also appreciated that the control panel may be a touch screen or other known controls for dishwashers. A power switch  22  (i.e., an on/off switch) may be located with the other buttons of the control panel or separate to allow for the selective operation of the dishwasher. 
         [0022]    A drive device such as a motor  24  may be located under or within the undercarriage to drive a wash pump (not shown) integrated with a rotating spray arm (not shown), and a drainage pump (not shown). A water solenoid  26  for controlling the flow of water into the dishwasher is shown on the bottom of the dishwasher. In a preferred embodiment, the kick panel or undercarriage  12  will include a panel that may be removed or opened to reveal an opening for receiving a filter system  30  of the present invention. A water line  28  connects the dishwasher to a hot water source to provide hot water for use in the dishwasher. 
         [0023]    Referring now to  FIGS. 2 through 4 , one embodiment of the filter system of the present invention is shown. The filter system, generally designated by the number  30 , includes: a base  34  with a hot water inlet  36  and a hot water outlet  38 ; a housing element  40  and a filter element or cartridge  42 . 
         [0024]    As shown in  FIGS. 3 and 5 , a top wall  48  extends across the interior width of the base  34  to define a cavity with the base&#39;s interior or circumferential walls  35 . One embodiment of the base  34  includes a central conduit  50  extending upward from the base and which is operably connected to the hot water outlet  38  to allow filtered water to flow into the dishwasher. 
         [0025]    A cylindrical wall  52  extends about the bottom of the conduit  50 , wherein the top of the cylindrical wall  52  provides a top surface  54  for engaging the end of the filter element  42  and creating a seal thereto. While a cylindrical wall is shown and disclosed, it is appreciated that other known methods of operably connecting or locating the filter element relative to the conduit may be used including, but not limited to, a threaded connection or twist locks and not depart from the scope of the present invention. 
         [0026]    An opening  58  in the top wall  48  in an area outside of the cylindrical wall provides a passage to operably connect the cavity of the base  34  to the hot water line inlet  36  to permit water to flow into the base  34  and filter element  42 . While the housing element  40  and base  34  may be sealingly connected in any known way, referring to  FIGS. 3 and 4 , one embodiment utilizes corresponding threads  62 ,  64  on the respective ends of the base  34  and housing element  40  to permit the housing element  40  to be twisted into engagement with the base  34 . The base and housing elements may be made out of a variety of non-water-permeable materials including, but not limited to, various polymers or steel. 
         [0027]    As shown in  FIG. 4 , the filter element or cartridge  42  includes a number of different sections or phases for water to pass through. In one embodiment, the cartridge may be sized such that it is about  10  inches long and 2½ inches wide to go into a standard  10  inch housing element; however, it is appreciated that it may be of a variety of different sizes and shapes depending on the system that is used in and not depart from the scope of the invention. The filter element  42 , in the embodiment shown in  FIGS. 4 and 5 , is sized to snuggly fit between the top surface  54  of the cylinder wall  52  and the inside  56  of the top of the housing element  40 . A rubber O-ring gasket  60  may be used at the bottom of the filter element to assist in providing a sealed connection with the cylindrical wall  52 . In order to prevent the water from entering the filter element other than through the first water permeable layer or inlet, the filter element preferably includes a protective casing  44  around most of the filter element. The casing is preferably a thin polymer casing, but may be made of a variety of thicknesses and materials that are not water permeable. 
         [0028]    When installed, water entering from the hot water inlet will pass through the base and pocket in the housing about the filter element and enter the filter element about it through an inlet at or proximate its top end (with reference to the view in  FIG. 4 ). Referring now to  FIG. 4 , a water permeable layer  70  may be located at or near the top or inlet of the filter element  42  to permit water to enter the filter element  42  for processing. One such embodiment of a water permeable layer is made of polypropylene (e.g., polypropylene wound fibers)  70 , which act to reduce film and sediment like sand and rust in the water. A perforated interior wall  80  may be used to provide support to the wound fibers or other water permeable layer  70 , and to permit water to flow into the interior of the filter cartridge  42 . When water does not enter the filter element through an opening in the top of the filter element, it is appreciated that a rubber O-ring gasket may also be used at the top of the filter element to provide a sealed connection with the inside of the top of the housing. 
         [0029]    An activated carbon layer  72  may be located within the filter element  42  after the water permeable layer  70  to filter out harmful chemicals and to improve the taste and odor of the water. The third phase or layer  74  includes cation resin, which filtrates and removes calcium and magnesium from hard water, and replaces it with sodium. Using the activated carbon layer before the cation layer will increase the life of the cation layer. The cation resin also acts to reduce spotting of dishes caused by hard water (e.g., calcium and lime deposits), and filtrates aluminum and lead. An example of a cation resin that may be used is Indion 225Na (crosslinked polystyrene and sulphonic acid) by Ion Exchange India Limited. 
         [0030]    A fourth phase or layer  76 , which may be located towards the outlet end of the filter element  42 , also may be a water permeable material such as, but not limited to, polypropylene wound fibers. A perforated interior wall  82  may be used to provide support to the wound fibers or other water permeable layer  76 , and to permit water to flow into the opening  66  of the filter cartridge  42  to permit water to flow out of the filter cartridge  42  and through the hot water outlet  38 . While the embodiment shown in the drawings is preferred, it is appreciated that the phases may be used in different orders and/or include different elements. 
         [0031]    In order to assist and retain the filter element  42  relative to the base  34 , the bottom end of the filter element  42  may include an opening  66  that is sized to accept the end of the central conduit  50  of the base  34 . While the filter element is shown as having a substantially cylindrical cross-section, it is appreciated that it may be of a variety of other cross-sections and not depart from the scope of the present invention. 
         [0032]    In operation, the base is installed within a dishwasher unit with the hot water line  28  connected to the hot water inlet  36  of the base  34  and the hot water outlet  38  being connected to an internal hot water line for dispensing hot water within the washing compartment of the dishwasher  10 . It is also appreciated that the base may be built into the dishwasher during manufacture. In order to permit replacement of a spent filter cartridge  42 , the base  34  may be aligned with an opening in the front or kick panel  12  of the dishwasher. If a filter element  42  is being replaced, the housing element  40  may be twisted in a counterclockwise direction to disengage the threads  64  of the housing element  40  from the corresponding threads  62  of the base  34 . The housing element  40  and the filter element  42  may be removed through the opening of the dishwasher  10 . Thereafter, a new filter element  42  may be placed through the opening so that the opening  66  in its bottom end extends over the central conduit  50 . The housing member  40  may then be inserted over the filter element  42  until its threads  64  engage the threads  62  at the top of the base  34 , wherein it may be rotated in a clockwise direction to removably fix the housing element  40  to the base  34 . 
         [0033]    In use, hot water flows through the hot water line and the hot water inlet  36  in the base  34  and into the cavity defined by the base  34  through opening  58 . The water then flows into the pocket in the housing element  40  (defined by the filter element and the interior wall of the housing element) and through the water permeable layer  70  into the filter element  42 . After passing through the activated carbon and cation resin layers  72 ,  74 , the water passes through the second water permeable layer  76  and into the central conduit  50 , where it then proceeds through the hot water outlet  38  into the dishwasher unit. 
         [0034]    Many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. Various modifications, changes and variations may be made in the arrangement, operation and details of construction of the invention disclosed herein without departing from the spirit and scope of the invention. The present disclosure is intended to exemplify and not limit the invention.