Abstract:
A water delivery system for delivering water to a water dispenser or an icemaker of a refrigerator includes a water inlet adapted to be connected to a fresh water supply, a water outlet connected to at least one of a water dispenser and an icemaker, and a flow sensor in fluid communication between the water supply and water outlet for generating flow signals which are used by a controller to determine flow rate and flow volume parameters for the system. The water delivery system also preferably includes a filter positioned between the water inlet and the flow sensor. The determined flow parameters are used for indicating a need for a filter change and to regulate the volume of water flowing to the water dispenser and/or icemaker.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention pertains to the art of refrigerators and, more particularly, to a water delivery system incorporating a water flow sensor in a refrigerator.  
         [0003]     2. Discussion of the Invention  
         [0004]     Providing water dispensers and automatic icemakers in household refrigerators has become extremely commonplace. In addition, there is a growing trend toward increasing the purity of all consumed water. For at least these reasons, it has heretofore been proposed in the art to incorporate a water purifying system in a refrigerator in order to filter the water supplied to a water dispenser and/or icemaker. Early proposed purifying systems of this type centered around providing a filtering unit between the water supply and the conduit entering the refrigerator. These systems were typically installed by service personnel as aftermarket add-on units. More recently, it has been proposed to incorporate filter assemblies during the overall manufacturing of refrigerators, while utilizing filters which can be fairly, readily accessed for replacement directly by consumers.  
         [0005]     The filter assemblies have a limited life span and must be replaced, generally after a given number of gallons have been filtered, in order to maintain the quality of the filtered water. It is often difficult to estimate the amount of water filtered by a particular filter assembly. Therefore, there exists a need to monitor the amount of water that has flowed through the filter assembly and to notify a customer when the filter&#39;s capacity has been reached.  
         [0006]     In addition, many refrigerators include water dispensing systems having control panels for allowing users to select desired amounts of water to be dispensed. However, the amount of water selected may not correspond to the amount of water actually dispensed due to factors such as variations in household water pressure. Variations in water pressure also affect the amount of water flowing to an icemaker. Therefore, ice cube size may not be consistent. Based on the above, there also exists a need in the art for an enhanced water dispensing system for a refrigerator, particularly a dispensing system that ensures a selected volume of water will be dispensed irrespective of variables such as household water pressure.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention is directed to a water delivery system, including a flow sensor, for delivering water to a water dispenser or an icemaker in a refrigerator. In accordance with a preferred embodiment of the invention, the water delivery system includes a water inlet adapted to be connected to fresh water supply and a water outlet connected to at least one of a water dispenser and an icemaker. The flow sensor, which is positioned between the water inlet and water outlet, outputs signals which are used to establish flow rate and volume parameters by a controller. The water delivery system preferably includes a filter positioned between the water inlet and the flow sensor. If the water flow rate falls below a predetermined level, the controller generates an output indicating a problem with the water delivery system. In this manner, the controller establishes an indication of when the filter needs to be replaced based on the amount of water that flows past the sensor. The controller is also coupled to a selection device operative to allow a user to control the volume of water flowing to the icemaker for varying ice cube size.  
         [0008]     Additional objects, features and advantages of the water delivery system of the invention will become more readily apparent from the following detailed description of a preferred embodiment, when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a perspective view of a side-by-side refrigerator incorporating a water delivery system constructed in accordance with the present invention;  
         [0010]      FIG. 2  is an exploded view of the water delivery system of the invention; and  
         [0011]      FIG. 3  is a block diagram of a control arrangement employed in connection with the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]     With initial reference to  FIG. 1 , a side-by-side refrigerator is generally indicated at  2 . In a manner widely known in the art, a side-by-side refrigerator  2  is formed from a cabinet shell  3  to which is pivotably attached a freezer compartment side door  5  and a fresh food compartment side door  7 . Side door  7  is shown open to expose a fresh food compartment  8  defined within cabinet shell  3 . Fresh food compartment side door  7  supports a plurality of vertically spaced shelves  11 - 14  and is also preferably provided with a dairy compartment  16 . In a preferred embodiment, fresh food compartment  8  is formed from an integral liner  20  having opposed side walls  22  and  23 , a rear wall  26  and top and bottom walls  28  and  29 . Secured to rear walls  26  by means of mechanical fasteners (not shown) are a pair of laterally spaced and vertically extending rails  32  and  33  that adjustably support various vertically spaced shelves  35 - 37 , as well as a shelf supporting bin assembly generally indicated at  39 .  
         [0013]     Also shown mounted within fresh food compartment  8  at top wall  28  is a temperature control unit  43 . Temperature control unit  43  is preferably molded of plastic and includes upper and lower slidable temperature control members  46  and  47  which can be used by a consumer to adjust the temperatures within side-by-side refrigerator  2  to preferable levels. As also shown in this figure, freezer compartment side door  5  is preferably provided with a dispensing unit  50  which can be used to selectively dispense either water or ice.  
         [0014]     In general, the above-described structure of side-by-side refrigerator  2  is known in the art and does not form part of the present invention. Instead, this description is provided for the sake of completeness. The present invention is particularly directed to a water delivery system having a flow sensor for supplying water either directly to dispensing unit  50  or to an automatic icemaker. Also included in the water delivery system is a replaceable filter, generally indicated at  55  in  FIG. 1 , which forms part of the water delivery system of the present invention. As shown, filter cartridge  55  preferably projects downward from within the housing of temperature control unit  43  at a central rear portion of fresh food compartment  8 . This location is utilized in accordance with the preferred embodiment to provide a readily visible and easily accessible filter cartridge  55  that can be replaced by a consumer as needed. However, other locations for replaceable filter  55  could be employed.  
         [0015]     Reference will now be made to  FIG. 2  in detailing the overall components and their interconnections for the water delivery system of the present invention. In accordance with the preferred form of the invention, a water supply (not shown) is attached to refrigerator  2  at dual valve  76 . More specifically, dual valve  76  includes an inlet  78  for attachment of the supply line, as well as first and second outlets  80  and  81 . Dual valve  76  is attached to refrigerator  2  by means of bracket  83  and preferably constitutes a solenoid-type valve having electrical connectors  86  and  87  which can be utilized to fluidly interconnect inlet  78  to one or more of the first and second outlets  80  and  81  in the manner which will be described more fully below. Outlets  80  and  81  are respectively connected to first and second water delivery tubes  89  and  90 , preferably through the use of compression nuts  91  and  92 . First and second water delivery tubes  89  and  90  converge by means of a Y-connector  95  into a common water delivery tube  98 . Tube  98  has a terminal end  100  that is connected to a water inlet  102  of a filter cartridge mounting head  105  through a connector  106 .  
         [0016]     Filter cartridge mounting head  105  is used to support filter cartridge  55  and therefore it is preferably mounted such that at least a portion of the housing of temperature control unit  43  encloses filter cartridge mounting head  105 . In any event, mounting head  105  includes a main body  108  which is preferably injection molded of plastic and attached to a bracket  110  by means of various screws  112 . In addition to water inlet  102 , mounting head  105  has associated therewith a water outlet  115  to which is attached a tube  117  by means of an elbow connector  119 . Tube  117  is preferably formed from plastic and 0.25 inches in diameter. The manner in which water flows through mounting head  105  from tube  98  to tube  117  will be detailed more fully below. An opposing end of tube  117  is connected through a fitting  123  to an inlet port  124  of a dispenser valve  125 . Dispenser valve  125  includes a first outlet  126  which is connected through a conduit  127  that leads to a water tank  128 . In a manner known in the art, water tank  128  is preferably mounted within fresh food compartment  8 , such as at lower rear portion thereof. Preferably, dispenser valve  125  is a solenoid-type valve having electrical connectors  29  and  30 .  
         [0017]     Since both valves  76  and  125  are preferably located outside of fresh food compartment  8 , conduit  127  has positioned therealong a spacer  133  that extends through liner  20  to permit sealing around conduit  127  during the injection molding of foamed insulation within cabinet  3  in a manner widely known in the art. For additional sealing purposes, seals  136 ,  137  and  139  are also provided. Seal  139  is actually associated with a tube  142  that leads from water tank  128 . More specifically, tube  142  includes a first section  143  that is interconnected to a second section  144  through a connector  145 . Second section  144  of tube  142  directly leads to the fountain of water dispensing unit  50 . Dispenser valve  125  also includes a second outlet  148  to which is attached a tube  149  that leads to a nozzle  153 . More specifically, tube  149  is attached to nozzle  153  by means of a clamp  155  and nozzle  153  is utilized to provide a flow of water to an icemaker generally indicated at  158 .  
         [0018]     With this arrangement, water supplied to refrigerator  2  is first delivered to valve  76 . Whether icemaker  158  or the fountain associated with dispensing unit  50  requires water will determine which side of dual valve  76  is actuated, thereby controlling the connection between the first and second water delivery tubes  89  and  90  with the flow into inlet  78 . Mounting head  105  normally has filter cartridge  55  attached thereto, such that water would flow into inlet  102  through common tube  98 , would be forced to flow through filter cartridge  55  and would be delivered to a water outlet  115 . The filtered water would then be delivered through tube  117  to dispenser valve  125  which would regulate whether the water would flow to water tank  128  and then dispenser unit  50  or to icemaker  158 .  
         [0019]     Two valves  76  and  125  are utilized to control the flow of water in the overall water circuit. These multiple valves are utilized in order to separate the electrical nodes and allow the water to flow to its desired source. However, there are various other types of water circuit arrangements which could be devised to perform this function, such as utilizing a valve in place of dual valve  76  which has a single input and output in combination with dispenser valve  125 . The disclosed embodiment is preferred since a single signal received from either the dispenser unit  50  or icemaker  158  can be used to control both valves  76  and  125  such that the water is routed in the desired path. In any case, all of the water for either the dispensing unit  50  or icemaker  158  is directed through mounting head  105  and, so long as the consumer has attached a suitable filter cartridge  55 , the purity of the water delivered to either dispensing unit  50  or icemaker  158  will be enhanced.  
         [0020]     At this point it should be noted that the overall configuration of the water delivery system as described above is known in the art as set forth in U.S. Pat. No. 6,303,031 which is incorporated herein by reference. Therefore, this discussion has been included for the sake of completeness. The present invention is more particularly directed to the inclusion and use of a flow sensor  160  in the overall water delivery system. As shown, flow sensor  160  is preferably positioned along tube  117 , between filter cartridge  55  and dispensing valve  125 . Flow sensor  160  is preferably a turbine meter. A signal generated by flow sensor  160  is sent to an electronic controller  162  (see  FIG. 3 ). Controller  162  utilizes signals from flow sensor  160  to determine both an accumulated flow volume and a flow rate based on the volume of water that passes through flow sensor  160  in a predetermined period of time.  
         [0021]     Typically, the flow rate of water passing through the water delivery system varies from about 10-20 cc/sec., depending on the water inlet pressure, which ranges from about 20-120 psi. By sensing the flow rate, controller  162  can be used to determine how long dispensing valve  125  should be opened to dispense the selected amount of water. For example, controller  162  may signal dispensing valve  125  to close after 140 cc+/−10 cc has passed through flow sensor  160 . Although controller  162  can regulate the flow of water in various ways, the most preferred embodiment of the invention has controller  162  electrically linked to contacts  129  and  130  of dispensing valve  125  for this purpose. The following table demonstrates how adjusting dispensing time allows a consistent amount of water to be dispensed (135 cc) regardless of inlet pressure.  
                                                             Actual Amount   Dispense time   Flow rate   Inlet Pressure       (cc)   (sec.)   (cc/sec.)   (psi)                                135.5   9.0   15   41.5       135.5   8.7   15   41.5       136.0   8.7   15   41.5       135.2   8.8   15   41.0       135.2   24.0   5   9.0       135.0   24.5   5   8.5       135.2   24.3   5   8.5       135.0   8.1   16   120.0       135.3   8.1   16   120.0       135.2   8.0   16   120.0       136.0   8.0   17   119.5                  
 
         [0022]     The following table indicates the differences in fill amounts due to inlet pressure in a water dispensing system without a flow sensor versus the present water delivery system including flow sensor  160 .  
                                                     Water Inlet   Fill Amount   Fill Amount       Pressure (psi)   without sensor (cc)   with sensor (cc)                                9.0       135.1       20.0   81.0       30.0   108.0       40.0   129.0   135.7       60.0   139.0       80.0   143.0       100.0   145.0       120.0   141.0   135.5                  
 
         [0023]     In accordance with the invention, a consumer may advantageously vary the size of ice cubes made in icemaker  158  by adjusting the fill amount. Since the fill amount is regulated based on signals provided by flow sensor  160 , the selected ice cube size will be consistent. Similarly, a specific amount of water can be selected to be dispensed from dispensing unit  50  regardless of the inlet pressure. For example, a consumer may select a fill amount of 4 oz., 8 oz., etc. Preferably, these adjustments are made through a series of buttons  163  or directly through a display  165  provided on dispensing unit  50  (see  FIG. 1 ).  
         [0024]     Although flow sensor  160  may be used in water dispensing systems that do not include filter cartridge  55 , employing flow sensor  160  in combination with filter  55  provides many advantages. For instance, through the use of flow sensor  160 , the total amount of water that has passed through filter  55  is preferably recorded, with this information being conveyed to a consumer by controller  162  and display  165 . With this arrangement, a consumer will know exactly when to change filter  55  based on the amount of usage. Flow sensor  160  is also capable of detecting when filter  55  needs to be changed due to clogging. More specifically, a baseline flow rate is preferably recorded when a new filter cartridge is installed. When the flow rate drops below a predetermined level, a signal will be generated to notify the consumer that filter  55  needs to be changed.  
         [0025]     A change filter indicator (not individually shown) is preferably located in display  165  or elsewhere. In accordance with a preferred embodiment of the invention, an indicator is provided in the form of an amber light that is illuminated in display  165  to notify a consumer that filter  55  needs to be changed soon. More specifically, the indicator includes a red light to notify the consumer when it is immediately necessary to change the filter. Most preferably, the indicator indicates a “% of filter life remaining” based on water usage pattern. To this end, signals from flow sensor  160  may also be used to record the overall amount of water that passes through the system or the average use over a specific period of time.  
         [0026]     The inclusion of flow sensor  160  in accordance with the invention also provides a number of diagnostic benefits, such as notifying a consumer when a low water flow condition exists due to low water pressure or downstream water leaks. Downstream water leaks may occur due to an improper door hinge connection or an icemaker fill tube leak. A lack of water in the flow system may also occur if the water supply is not connected properly. In any case, water flow sensor  160  sends information to controller  162  which can shut down the system and notify the consumer of such conditions. Signals from flow sensor  160  can also be used to lock out icemaker  158  when water dispensing unit  50  is in use so that consumer selected fill amounts are not affected by the simultaneous use of water.  
         [0027]     Based on the above, it should be readily apparent that various changes and/or modifications can be made to the present invention without departing from the spirit thereof. Certainly, although described with reference to a side-by-side refrigerator, the water dispensing system and flow sensor of the invention could be used on various styles of refrigerators. In addition, although the preferred embodiment alters the water flow time through the system by controlling whether a single valve is opened or closed, this function could be performed in other ways, such as by controlling an adjustable flow characteristic associated with one or more variable position valves. Furthermore, the flow sensor of the invention could be employed in conjunction with other overall refrigerator water dispensing systems, including both single and dual control valve arrangements. In any event, the invention is only intended to be limited by the scope of the following claims.