Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to the art of refrigerators and, more particularly, to a control system for operating a refrigerator ice/water dispenser. 
     2. Discussion of the Prior Art 
     Door mounted ice/water dispensing systems are widely known in the art of refrigerators. Depending upon a particular refrigerator model, the dispensing systems are available with a variety of options. For example, top mount and bottom mount refrigerators typically only include a water dispensing option, while side-by-side models include both water and ice dispensing options. Ice dispensing may also include options for dispensing crushed and/or cubed ice. In most instances, the dispensing system will generally include a switch that is activated by a glass or other beverage holder to initiate dispensing either water or ice. 
     Regardless of the particular dispensing system employed, non-intentional dispensing is highly undesirable. More specifically, it is highly undesirable for the dispensing system to begin releasing ice and or water without any user input as non-intentional dispensing of ice and/or water creates a mess for the consumer and may damage certain kitchen floor surfaces. An electrical short circuit, electronic or other component failure could potentially activate the dispensing system without activation of the switch. 
     In order to address this problem, manufacturers have developed various circuits that attempt to minimize the likelihood of a non-intentional dispensing event. One example of such an effort can be found in U.S. Pat. No. 4,739,233 directed to a motor control circuit for an ice dispensing system. The disclosed motor control routes current to a motor actuator through a dispensing actuation switch. While effective at reducing the risk of a non-intentional dispensing event, a ground short in any one of a number of locations in the motor control, circuit will activate a dispensing motor, causing ice to be released regardless of consumer demand. In addition, the system requires periodic cessation of power to the dispenser to check the position of the dispensing actuation switch. This requirement adds unnecessary complexity to the motor control. 
     Based on the above, despite the existence of dispensing control systems in the prior art, there still exists a need for a more advanced ice/water dispensing control system. More specifically, there exists a need for a dispensing control system that incorporates fail safe systems to more effectively minimize any potential non-intentional dispensing event. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a control system for a refrigerator ice/water dispensing unit. The control system includes an actuation switch, a drive unit that is selectively activated to release either ice or water, a control switch that controls operation of the motor, and a power system having multiple power supplies for operating the control system, control switch and drive unit. Preferably, the dispensing unit includes multiple actuation switches, e.g. a water activation switch and a water/ice activation switch, for independently controlling the release of water and ice respectively. 
     In accordance with the invention, the control system includes a first drive unit in the form of a water valve and a second drive unit or auger. The first and second drive units are coupled to corresponding first and second control switches. In addition, the control system includes an ice selection switch coupled to an ice selection control switch. A processor, having multiple inputs and multiple outputs, routes signals to appropriate ones of the first and second control switches, as well as the ice selection control switch depending upon a given consumer selection at a dispenser keypad. 
     In accordance with the most preferred form of the invention, activation current for the first and second control switches, as well as the ice selection control switch, passes through a switching device, and activation current for the switching device must pass through one of the water activation switch and the water/ice activation switch. Preferably, the control system includes first and second control circuits. The first control circuit operates the drive units, while the second control circuit enables operation of the first control circuit, while interfacing with the consumer. 
     In further accordance with the most preferred form of the invention, both the water activation switch and the water/ice activation switch are constituted by membrane switches coupled to the processor. The membrane switches are connected to a very low voltage source in the processor, the first, second and ice control switches are coupled to a low voltage source, and the first and second drive units are connected to line voltage. This arrangement not only avoids unintentional dispensing, but ensures that only trace voltage levels are present at the dispenser keypad. 
     Additional objects, features and advantages of the present 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 
         FIG. 1  is an upper left perspective view of a side-by-side refrigerator having an water/ice dispenser including a dispenser control system constructed in accordance with the present invention; 
         FIG. 2  is an enlarged perspective view of the water/ice dispenser and control system of  FIG. 1 ; 
         FIG. 3  is a schematic view of a first portion of the dispenser control system constructed in accordance with the present invention; and 
         FIG. 4  is a schematic view of a second portion of the dispenser control system. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With initial reference to  FIG. 1 , a refrigerator  2  includes an outer shell or cabinet  4  within which is positioned a liner  6  that defines a fresh food compartment  8 . In a manner known in the art, fresh food compartment  8  can be accessed by the selective opening of a fresh food door  10 . In a similar manner, a freezer door  12  can be opened to access a freezer compartment  13 . In the embodiment shown, freezer door  12  includes a dispensing unit  14  that enables a consumer to retrieve a water product, such as ice and/or fresh water, without accessing fresh food or freezer compartments  8  and  13 . For the sake of completeness, fresh food door  10  is shown to include a dairy compartment  15  and various vertically adjustable shelving units, one of which is indicated at  16 . 
     In a manner known in the art, fresh food compartment  8  is provided with a plurality of vertically adjustable shelves  20 - 22  supported by a pair of shelf support rails, one of which is indicated at  25 . At a lowermost portion of fresh food compartment  8  is illustrated a pair of temperature controlled bins  28  and  29 , as well as a conventional storage compartment  30 . At an upper region of fresh food compartment  8  is a temperature control housing including a user interface  40 . In the embodiment shown, interface  40  includes a display zone  42  and a plurality of control elements  45 - 49 . Interface  40  also includes a light  63  which, in a manner known in the art, is controlled by a switch  65  operated by opening and closing fresh food door  10 . Refrigerator  2  also includes a power system  70  for supplying power at various voltage levels to various components such as a compressor, fans and light  63 , as well as components of dispensing unit  14  in a manner that will be detailed more fully below. 
     As best shown in  FIG. 2 , dispensing unit  14  includes a facade  94  mounted to freezer door  12 . Facade  94  includes a recessed portion  98  for receiving a beverage container, such as a glass, for collecting any water and/or ice released from dispensing unit  14 . Dispensing unit  14  also includes a base portion  105  which is designed to catch small amounts of water and/or ice which may drip or otherwise be released from dispenser unit  14  when a container is not in recessed portion  98 . Dispensing unit  14  further includes a user interface or keypad  110  having a plurality of user selection members or keys  114 - 118  and a display  124 . Keys  114  and  115  control a dispenser light (not shown) and menu options, e.g., filter reset and dispenser lock out, respectively, while keys  116 - 118  enable a consumer to select between dispensing water, crushed ice or cubed ice. In addition, dispensing unit  14  is provided with actuation switches that trigger release of water and/or ice. In the embodiment shown, dispensing unit  14  includes a first or water/ice activation switch  128  positioned within recessed portion  98  that is designed to be acted upon by a beverage container, as well as a sport water activation switch  130  for releasing water either independent from or in conjunction with ice activation switch  128 . In any event, the above described structure is provided for the sake of completeness and to enable a better understanding of the figures. Instead, the present invention is particularly directed to a control system  140  for dispensing unit  14 . 
     As best shown in  FIGS. 3 and 4 , control system  140  includes first and second control circuits  142  and  144 . First or main control circuit  142  controls operation of main dispensing components as will be discussed more fully below, while second or fountain control circuit  144  provides signals to main control circuit  142  enabling activation of the main dispensing components in a manner that will also be discussed more fully below. With particular reference to  FIG. 3 , main control circuit  142  is operatively connected to a first motor or drive unit  157  which, in accordance with the present invention, constitutes an activation solenoid of a water valve. Main control circuit  142  is also operatively connected to a second motor or drive unit shown  159  which takes the form of an ice dispensing auger. Main control circuit  142  also contains a crushed ice select line  161  that provides input to auger  159  causing ice to be directed through a crusher depending upon user preferences. In any event, water valve  157  and auger  159  are coupled to a power supply  163  which provides line voltage, preferably approximately 120 volts, from power system  70 . Power supply  163  also feeds a power supply box  164 , which provides low voltage (preferably approximately 12 volts) to main control circuit  142  and, through line  165 , to fountain control circuit  144 . 
     In accordance with the invention, main control circuit  142  includes a plurality of control switches  169 - 171  which control operation of water valve  157 , auger  159  and crushed ice select line  161  respectively. Each control switch  169 - 171  includes a corresponding relay portion  178 - 180  that selectively engages a contact portion  184 - 186  coupling water valve  157 , auger  159  and crushed ice select line  161  to power supply  163 . In addition, each relay portion  178 - 180  includes a corresponding diode circuit  189 - 191  to prevent feedback voltage from a corresponding one of control switches  169 - 171 . As will be discussed more fully below, each relay portion  178 - 180  is activated by power supplied from a relay control line  194  through a respective drive switch  197 - 199 . More specifically, drive switches  197 - 199  include corresponding control input terminals  204 - 206 , as well as respective first and second main terminals  207 ,  208 ,  210 ,  211  and  213 ,  214 . Input terminals  204 - 206  are activated by signals provided by a main processing unit  216 . A signal from main processor  216  at one or more of input terminals  204 - 206  allows current to pass from relay control line  194  to a respective control switches  169 - 171 . The particular drive switch  197 - 199  activated depends upon signals received based on the pressing of a key  116 - 118  from keypad  110  through a signal line  218  in a manner that will be discussed more fully below. Main processor  216  receives power from power supply box  164  which is coupled to power system  70  and includes a voltage regulator circuit  220  that outputs very low voltage, preferably approximately 5 volts. 
     With reference to  FIG. 4 , fountain control circuit  144  includes a second or fountain processor  240  coupled to a voltage regulator circuit  242  that supplies approximately 5 volts and, as described above, is coupled to power supply box  164  through line  165 . Processor  240  is also coupled to dispensing switches  128  and  130 . More specifically, each dispensing switch  128 ,  130  preferably takes the form of a membrane switch having corresponding first and second terminals  244 ,  245  and  247 ,  248 , with first terminals  244 ,  247  receiving power from processor  240  through a supply line  254  and second terminals  245 ,  248  providing a switch status signal to processor  240  through a corresponding return line  257 ,  258 . Preferably, processor  240  pulses supply line  254  until sensing that a dispensing switch  128 ,  130  has been closed through a corresponding return line  257 ,  258 . Once processor  240  senses that one of dispensing switches  128 ,  130  has been closed, power is provided to supply line  254  continuously until switch  128  or  130  is released. In any event, from the above description, it should be understood that main control circuit  142  and fountain control circuit  144  are linked by four lines, i.e., lines  165 ,  194 ,  218  and a common or ground line  293 . 
     In addition to providing an input signal to processor  240 , switches  128  and  130  enable current to pass along relay control line  194  to first control circuit  142 . As each switch  128 ,  130  provides current to relay control line  194  in a similar manner, a detailed description will be made with respect to the closing of dispensing switch  128  with an understanding that the closing of dispensing switch  130  operates in a similar manner. Once switch  128  is closed, a signal is sent through return line  257  into a branch circuit  280 , through a diode D 1  and resistor R 1 , and into an input terminal  283  of a first switching unit  284 . Once power is provided at input terminal  283 , switching unit  284  enables low voltage power, preferably approximately 12 volts, to pass from power supply box  164  through a resistor R 2 , resistor R 3 , and first and second main terminals  291 ,  292  of switching unit  284  before passing to ground line  293 . After passing through resistor R 2 , current is also received at a second input terminal  295  of a second switching unit  297 . At this point, low voltage from power supply box  164  can pass through first and second main terminals  305 ,  306  of second switching unit  297  into relay control line  194  and pass to first control circuit  142 . In this manner, switching unit  284  and switching unit  297 , as well as resistors R 1 -R 4 , form an overall switching device of second control circuit  144 . 
     Once relay control line  194  is powered, current is received at first main terminals  207 ,  210  and  213  of drive switches  197 - 199  respectively. Having received a signal from a switch  116 - 118  on keypad  110 , main processor  216  selectively activates one or more of input terminals  204 ,  205  and  206  of drive switches  197 - 199  in order to allow current to pass to one or more of control switches  169 - 171 . Thus, for example, if a consumer simply wants to dispense water from dispensing unit  14 , activating switch  128  and key  116  sends power along relay control line  194 , while main processor  216  provides a signal to input terminal  204 , thereby allowing control switch  169  to activate water valve  157 , releasing water from dispensing unit  14 . In a similar manner, the operation of control switch  170 , with or without control switch  171 , can be controlled. 
     At this point, it should be understood that the present invention provides a control system that ensures that single or multiple electronic component failures will not result in unintended dispensing of a water product from dispensing unit  14 . That is, by ensuring that current passes through dispensing switches  128  and/or  130 , and by providing multiple levels of redundancy, such as switching units  284 ,  297  and drive switches  197 - 199 , dispensing unit  14  will not release a water product without being activated by a consumer. In this way, second control circuit  144  actually regulates the ability of main processor  216  to operate drive units  157  and  159 . Therefore, a short in main processor  216 , which could potentially provide a signal to one or more of input terminals  204 - 206 , would still not enable an unintended dispensing operation to occur. Similarly, a short in fountain processor  240  would not enable power to flow through relay control line  194 . Moreover, the use of three different voltage levels provides a further control degree against an unintentional dispensing operation, while also enabling membrane switches to be readily used in dispensing unit  14  given the minimal voltage levels maintained at dispensing unit  14  at all times. 
     Although described with reference to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, the number and types of switching units, drive units, and the like can be varied without departing from the spirit of the present invention. In addition, the control system could also be employed to dispense other substances, such as juice and other water-based products. In general, the invention is only intended to be limited by the scope of the following claims.

Technology Category: 2