Patent Publication Number: US-8540118-B2

Title: Water dispenser and method of operating it

Description:
BACKGROUND OF THE INVENTION 
     The present disclosure relates generally to water dispensers. More particularly, the present disclosure relates to a point of use water dispenser that has a control system that prevents the water refill valve from refilling the water reservoir or tank when there is a leak in the water dispenser, and a method of operating such a water dispenser. 
     A point of use water dispenser generally includes a water reservoir or tank fluidly connected to a water refill valve. The water refill valve is in turn fluidly connected to a water source, such as, for example, a tap connected to a municipal water source. The water refill valve controls the amount of water supplied to the water reservoir. Water is preferably passed through a filter to filter the water prior to being deposited in the water reservoir. Generally, a faucet is fluidly connected to the water reservoir, which allows a consumer to draw water from the water reservoir. 
     A problem in the existing water dispensers is that an internal leak may develop over time, causing property damage due to water spillage. The maximum leakage with the traditional “bottled” water dispensers is limited by the physical size of the bottle. A “plumbed-in” point of use water dispenser, however, has a much higher risk of property damage, as the water supply is unlimited and therefore requires special design considerations to mitigate this risk. 
     For example, in the point of use water dispensers, if there is a leak, the water refill valve may be controlled to open to refill the water reservoir periodically, only to have the water reservoir drain again in a period of time over the floor of the home or office. If not monitored, a substantial amount of water may be drained from the water reservoir, which can cause relatively considerable amount of damage to the home or office. Generally, a customer will be very displeased since if the customer is not closely monitoring the water dispenser then a considerable amount of spillage may potentially occur over a relatively short period of time. 
     BRIEF DESCRIPTION OF THE INVENTION 
     As described herein, the various exemplary embodiments of the present invention overcome one or more of the above or other disadvantages known in the art. 
     One aspect of the present disclosure relates to a water dispenser that is fluidly connectable to a water source. The water dispenser includes a water tank; a faucet fluidly connected to the water tank and configured to generate an activation signal after being activated; a valve fluidly connectable to the water source and fluidly connected to the water tank; a first float switch movably disposed in the water tank and configured to generate an open signal after moving away from a predetermined position; and a controller operatively connected to the faucet and the first float switch. The controller is configured to open the valve to refill the water tank with water from the water source after the controller receives both the activation signal from the faucet and the open signal from the first float switch. 
     Another aspect of the present disclosure relates to a method of controlling a water dispenser. The water dispenser includes a water tank, a faucet fluidly connected to the water tank, a valve fluidly connectable to a water source and fluidly connected to the water tank. The method includes opening the valve to refill the water tank with water from the water source only after receiving an activation signal from the faucet and an open signal from a first float switch movably disposed in the water tank. 
     These and other aspects and advantages of the present disclosure will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the disclosure, for which reference should be made to the appended claims. Moreover, the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a point of use water dispenser according to an exemplary embodiment of the present disclosure. 
         FIG. 2  is another perspective view of the water dispenser of  FIG. 1 , with a cover being removed to show a water filter therein;  FIG. 2  also shows the tubing and the water tap valve that are used to connect the water dispenser to a municipal water supply. 
         FIG. 3  is block diagram of the water dispenser of  FIG. 1 , schematically showing some components of the water dispenser. 
         FIG. 4  is a simplified, partial view of the water dispenser of  FIG. 1 , schematically showing some components of the water dispenser. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE INVENTION 
     It is contemplated that the teaching of the present disclosure set forth below is applicable to all types of water dispensing devices, including but not limited to, point of use water dispensers, water filtration devices, consumer water dispensers, commercial water dispensers, household refrigerators, or water bottling devices. The present disclosure is therefore not intended to be limited to any particular apparatus or configuration described in the exemplary embodiments of the present disclosure. It should be appreciated that the present disclosure may be applicable to other types of appliances that dispense water or fluid including commercial refrigerators, appliances with faucets, icemakers, water bottlers, food manufacturing equipment, freezers, or any other type of appliance that may include a point of use water dispenser known in the art. 
       FIG. 1  illustrates a point of use water dispenser  10  including, among other things, a housing  14  and a dispenser shelf  16  where a user may place a cup to receive water. The point of use water dispenser  10  also includes a cover  17  located in a lower portion of the water dispenser  10  that is secured via a hinge or the like to the chassis of the water dispenser and has a handle  19  for facilitating the opening of the cover  17  to reveal one or more interior components of the water dispenser  10 . The water dispenser  10  includes switches or faucets  12   a ,  12   b ,  12   c  for dispensing hot water, room temperature water, or cold temperature water from respective outlets. Other configurations are possible and the water dispenser  10  is not limited to the three switches  12   a ,  12   b ,  12   c  shown. The water dispenser  10  is shown as a so called “bottle-less” dispenser where a water reservoir  205  (shown in  FIG. 4 ) is placed inside the housing  14 ; however, the present disclosure encompasses a bottle configuration where a water bottle is placed on a top side  15  of the housing  14  to fill the water reservoir  205 . 
     The water dispenser  10  advantageously limits water leakage or does not allow an endless flow of water escaping from the water dispenser  10  from the municipal water supply. Such leakage may damage the floor of the home or office. Instead, the water dispenser  10  will only open a refill valve to refill the water reservoir  205  when certain conditions are met. If there is a leakage, the water dispenser  10  will not dispense water in an endless manner. 
     Turning now to  FIG. 2 , the water dispenser  10  preferably includes a water filter  18  that is disposed in the housing  14  under the shelf  16  for a single stage filtration of the water in the water dispenser  10 . A tubing  20  fluidly connects the water dispenser  10  to a water tap valve  22 . In operation, the municipal water supply is connected to the water tap valve  22 . The water tap valve  22  shown in  FIG. 2  is typically known as a saddle valve. Water will flow from the municipal water supply through the water tap valve  22  and through the tubing  20  into the point of use water dispenser  10  where the filtration of the water occurs. 
     Turning now to  FIG. 3 , there is shown a simplified block diagram of the water dispenser  10 . The water dispenser  10  includes a computing device  100  that includes a controller  110  that may be a digital signal processor manufactured with an arithmetic logic unit (ALU), a control unit and registers as is known in the art. Alternatively, the controller  110  can be a digital control circuit or an analog circuit. The controller  110  is configured to deliver control signals to various components of the water dispenser  10 . Various configurations are possible and within the scope of the present disclosure, and therefore the configurations shown therein form no limitations to the present disclosure. 
     The controller  110  is operatively connected to a bus  120 . As is known in the art, the bus  120  enables communications between the controller  110  and other components of the water dispenser  10  so that the controller  110  can control the operation of these components. 
     As illustrated in  FIG. 3 , in one embodiment, the bus  120  is operatively connected to a memory  180  that may include a main memory and secondary storage for storing executable program instructions and for writing to the memory  180  as is known in the art, to an input/output device  140  (such as a keyboard, a touch screen), to a display  150  which is used for displaying/monitoring one or more conditions of the water dispenser  10 , to a heater  213  and a cooling device  170  that are selectively used to control the temperature of the water to be dispensed by the water dispenser  10 , to an alarm  130  that can be used to alert the user of one or more conditions of the water dispenser  10 , to a timer  110   a , to a refill valve such as a solenoid valve  224  for the water reservoir  205 , to float switches  203 ,  204   a , and  204   b , and to a switch or faucet  220  which corresponds to one of the faucet  12   a ,  12   b ,  12   c  shown in  FIG. 1 . A power supply  190  provides electricity to many components of the water dispenser  10 . 
     Turning now to  FIG. 4 , operation of the water dispenser  10  that provides improved control and eliminates endless leakage will be described. The saddle valve  22  of  FIG. 4  is fluidly connected to a municipal water supply as discussed above in connection with  FIG. 2 . The tubing  20  fluidly connects the saddle valve  22  to a single stage manifold and filter assembly  227 . The filter of the assembly  227 , which corresponds to the filter  18  in  FIG. 2 , may include various filter media. The filter media may include a surface filter, or a solid sieve which traps the solid particles, with or without the aid of filter paper (e.g., Buchner funnel, belt filter, rotary vacuum-drum filter, cross flow filters), or a second depth filter (a bed of granular material which retains the solid particles as it passes). The single stage manifold and filter assembly  227  filters particulates from the municipal water and communicates the filtered water to the solenoid valve  224 , which is then communicated to the water reservoir  205  as discussed herein. 
     The solenoid valve  224 , which is an electromechanical valve controlled by an electric current through a solenoid coil, may be opened to release water into the water reservoir tank  205 . Other types of valves can be used, but solenoid valve is preferred because it offers fast and safe switching, is highly reliable, and has a relatively long service life, low power requirements and a compact design. The solenoid valve  224  preferably has two ports—one port for receiving water from the single stage manifold and filter assembly  227  and the other port for releasing water into the water reservoir  205  and then to a hot water reservoir or tank (not shown) via a flow connection  212   a . However, the solenoid valve  224  may have more than two ports. 
     In the case of a two-port solenoid valve  224  the flow is switched on or off by the electrical current. It should be appreciated that the present water dispenser  10  advantageously uses a single solenoid valve  224 . This configuration is advantageous as the solenoid valve  224  is relatively expensive. By using just one solenoid valve  224  instead of multiple solenoid valves, the production costs for the water dispenser  10  can be lower. However, multiple solenoid valves can be used. For example, the water dispenser  10  can have two solenoid valves, the second valve being used to supply water from the single stage manifold and filter assembly  227  to the hot water reservoir directly without using the flow connection  212   a . The solenoid valve  224  is used to release water into the water reservoir  205  when opened and to terminate releasing water into the water reservoir  205  when closed. 
     A separator plate  202  is disposed in the water reservoir  205  to roughly divide the water reservoir  205  into a first portion  205   a  and a second portion  205   b . In the embodiment shown in  FIG. 4 , the separator plate  202  does not seal the first portion  205   a  relative to the second portion  205   b  so that these portions  205   a ,  205   b  are still fluidly connected to each other. The cooling device  170  shown in  FIG. 3  includes an evaporator  213   a  of a sealed refrigeration system. The evaporator  213   a  surrounds the second portion  205   b  to primarily cool the water contained in the second portion  205   b  while not covering at all the first portion  205   a . In this manner, the first portion  205   a  holds relatively warm or room temperature water while the second portion  205   b  holds relatively cold water. Preferably, the inlet end of the flow connection  212   a  is disposed in the first portion  205   a  so that water flowing into the hot water reservoir is relatively warm. As is known in the art, the hot water reservoir is heated by the heater  213  ( FIG. 3 ) which can be, for example, an electric heater. 
     Preferably, an upper float switch  204   a , a lower float switch  204   b  and a warning or third float switch  203  are disposed in the first portion  205   a  of the water reservoir  205 . In the embodiment shown, the upper float switch  240   a  and the lower float switch  204   b  share a common anchoring post  204   c  which is supported by the top  205   t  of the water reservoir  205 , and the warning float switch  203  has its own anchoring post  203   c  which is also supported by the top  205   t . In the embodiment shown in  FIG. 4 , at their lowermost positions, the upper float switch  204   a  is disposed above the lower float switch  204   b , but below the warning float switch  203 . In one embodiment, the warning float switch  203 , in its lowermost position, is higher than the upper float switch  204   b  when the upper float switch  204   b  is in its uppermost floating position. These float switches are known in the art, and the function of these float switches in the embodiments will be apparent from the following discussions. 
     The switch or faucet  220  is fluidly connected to the second portion  205   b  of the water reservoir  205  through the flow connection  213   b . The switch or faucet  220  preferably has a mechanical valve  220   a  with an outlet  233 , and a micro switch  232  which is operatively connected to the mechanical valve  220   a  and is schematically illustrated in  FIG. 4 . The micro switch  232  is also operatively connected to the controller  110 . Activating the mechanical valve  220   a  will activate the micro switch  232  by opening or closing circuit of the micro switch  232 , and such opening or closing will send a signal to the controller  110 . Similarly, deactivating the switch or faucet  220  will close or open the circuit of the micro switch  232 , and such closing or opening will send another, different signal to the controller  110 . 
     In the embodiment shown in  FIG. 4 , each of the first portion  205   a  of the water reservoir  205  and the hot water reservoir has its own switch or faucet (not shown), which is fluidly connected to the first portion  205   a  or the hot water reservoir by a separate flow connection (not shown) and corresponds to the respective one of the switches  12   a ,  12   b  and  12   c  shown in  FIG. 1 . In another embodiment, only one switch or faucet can be used, which is then fluidly connected to the first portion  205   a , the second portion  205   b  and the hot water reservoir, respectively, in a known manner. 
     After the installation of a new water dispenser  10  which has no water in the water reservoir  205 , all three float switches  203 ,  204   a ,  204   b  are in their lowermost positions. Activating the mechanical valve  220   a  of the faucet  220  will activate the micro switch  232 , which will then send a signal to the controller  110  to activate or open the solenoid valve  224  to fill the water reservoir  205  with water. The solenoid valve  224  will remain open even if the user deactivates the mechanical valve  220   a  at this point. As the solenoid valve  224  remains open, water will be supplied to the water reservoir  205  and water level in the water reservoir  205  will raise to move the lower float switch  204   b  upward from its lowermost position. In one embodiment, the lower float switch  204   b  is configured to send a signal to the controller  110  to activate the cooling device  170  and/or the heater  213  when it moves from its lowermost position to an upper position such as its uppermost floating position. The solenoid valve  224  remains open to fill the water reservoir  205  with water until the upper float switch  204   a  moves upward and/or reaches a predetermined upper position such as its uppermost floating position, at which position the upper float switch  204   a  sends a signal to the controller  110  to deactivate or close the solenoid valve  224 . 
     At this initial water filling stage, the controller  110  can be programmed or configured to use the timer  110   a  to limit the on-time of the solenoid valve  224  to a predetermined period of time. The predetermined period of time is chosen so that if everything works as planned, water in the water reservoir  205  will reach its designed maximum water level within this predetermined period of time. This on-time limit prevents burn-out damages to the solenoid valve  224  when there is an incomplete or improper installation or when municipal water supply is shut off for some reasons. The controller  110  can be programmed or configured to activate the alarm  130  and/or to turn on the display  150  if one or both of the lower and upper float switches  204   b ,  204   a  do not reach their uppermost floating positions within the predetermined period of time. In one embodiment, the predetermined period of time is approximately 4 minutes. 
       FIG. 4  shows that the water reservoir  205  has the designed maximum water level so that both the upper and lower float switches  204   a ,  204   b  are in their uppermost floating positions, but the warning float switch  203  remains in its lowermost position. If a user activates the mechanical valve  220   a , water will be dispensed from the water reservoir  205 , and the water level in the water reservoir  205  will decrease, which will cause the upper float switch  204   a  and/or both the upper and lower float switches  204   a ,  204   b  to move from their uppermost floating positions to lower positions. In one embodiment, it is the lower float switch  204   b  that will send an open signal to the controller  110  when it moves downward from its uppermost floating position, but the upper float switch  204   a  may be used instead to send this open signal. As discussed earlier, activation of the mechanical valve  220   a  will also activate the micro switch  232  which will then send an activation signal to the controller  110 . The controller  110  will send a signal to open the solenoid valve  224  to refill the water reservoir  205  with water only after it receives both the open signal from one of the upper and lower float switches  204   a ,  204   b , and the activation signal from the micro switch  232  of the switch or faucet  220 . 
     The controller  110  may be programmed or configured so that it requires not only the receipt of the two signals (i.e., the activation signal and the open signal) but also the receipt of the two signals in a sequence (i.e., the activation signal no later than the open signal). This allows for a redundancy and safe operation, as the water reservoir  205  will not be continuously refilled if the water dispenser  10  is leaking. 
     Furthermore, the controller  110  may be programmed or configured so that it will activate the solenoid valve  224  after receiving the two signals and the expiration of a predetermined period of time. Delay is preferred here because more mixing of water in the water reservoir  205  while water is being dispensed from the water dispenser  10  is not desirable because if there is a substantial temperature difference between the water dispensed and the water temperature expected by a user, the user may infer incorrectly that the water dispenser is malfunctioning. The delay may be under a minute, about a minute or about several minutes, depending on the size of the water reservoir  205  and the water dispensing ratio. The controller  110  can use the timer  110   a  to count the delay, and start to activate the solenoid valve  224  immediately after the expiration of the predetermined period of time which starts, for example, when the upper float switch  203   a  moves downward from its uppermost floating position, when the upper float switch  203   a  reaches its lowermost position, when the lower float switch  203   b  moves downward from its uppermost floating position, or when the lower float switch  203   b  reaches its lowermost position. 
     Once activated, the solenoid valve  224  remains open until water in the water reservoir  205  moves the upper float switch  204   a  upward from its lowermost position and/or reaches its uppermost floating position, at which position the upper float switch  204   a  sends a close signal to the controller  110  to deactivate or close the solenoid valve  224 . 
     The lower float switch  204   b  can be used to deactivate the cooling device  170  and/or the heater  213 . For example, when the lower float switch  204   b  moves from its uppermost floating position to a lower position such as its lowermost position, it sends a signal to the controller  110  to deactivate the cooling device  170  and/or the heater  213 . Of course, the upper float switch  204   a  can be used for this purpose also. 
     The lower float switch  204   b  can also be used to provide a signal to the controller  110  to start the timer  110   a . The timer  110   a  sets the time cycle that the solenoid valve  224  is allowed to stay open. At the commencement of the time cycle, the solenoid valve  224  is opened. At the conclusion of the time cycle, the solenoid valve  224  is closed. The time cycle may include various different cycles and may depend on the water holding capacity of the water dispenser  10 , mass flow rate of water through components of the water dispenser  10  and other factors and may be programmed accordingly. For example, in the event that the mechanical valve  220   a  remains activated or open, the solenoid valve  224  will remain activated or open only for a predetermined period of time, such as for example approximately 7 minutes, after the controller  110  sends a signal to activate the solenoid valve  224 . This feature prevents damages to the solenoid valve  224  due to forced continuous operation by the user when the user keeps the mechanical valve  220   a  in an activated state. The controller  110  resets the time cycle whenever the upper float switch  204   a  reaches its uppermost floating position and sends a close signal to the controller  110  to deactivate the solenoid valve  224 , or whenever the mechanical valve  220  is deactivated or closed, for example. 
     The warning float switch  203  is disposed a predetermined distance higher than the upper float switch  204   a . The predetermined distance can be less than a height of an individual float switch as shown. The warning float switch  203  is optional. In one embodiment, the warning float switch  203  is directly wired or connected (i.e., a direct connection without passing through the controller  110 ) to the solenoid valve  224 . When there is a malfunction in the upper float switch  204   a  and/or the controller  110  while the solenoid valve  224  is still activated and water is still supplied to the water reservoir  205 , the warning float switch  203  will deactivate the solenoid valve  224  and therefore shut down the water supply to the water reservoir  205  when, for example, it moves upward from its lowermost position or when it reaches its uppermost floating position. In this manner, the warning float switch  203  prevents overfilling the water reservoir  205  and spill of water onto the floor of the home or office. The warning float switch  203  can also be directly wired to the alarm  130  so that once the warning float switch  203  is triggered when it moves upward from its lowermost position or reaches its uppermost floating position, the alarm  130  will be triggered to warn a user, audibly and/or visually, that there is a malfunction in the water dispenser  10 . 
     It should be appreciated that generally the controller  110  may receive signals from the mechanical valve  232  and float switches  203 ,  204   a ,  204   b  to control the solenoid valve  224  that are not simultaneous. It should be appreciated that the controller  110  may search for signals from the mechanical valve  232  and float switches  203 ,  204   a ,  204   b  continuously and receive the signals simultaneously and also over a predetermined time frame and then output control commands. 
     Thus, while there have shown and described and pointed out fundamental novel features of the disclosure as applied to various specific embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the apparatus illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the disclosure. For example, since the first portion  205   a , the second portion  205   b  and the hot water reservoir are fluidly connected to each other, they are considered as forming one water tank in the present disclosure. Furthermore, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.