Abstract:
A system controls dispensing different chemicals received from containers at a plurality of ports. Each container has data thereon that identifies the chemical within the container. The system reads the data from each container to determine which port is associated with each chemical. When a given chemical is required, the system activates a flow control device coupled to the port associated with that given chemical, thereby supplying the given chemical to a consuming device. Therefore regardless of into which port an operator places a particular chemical, the system automatically knows which port has which chemical and the dispensing is configured accordingly. Various mechanisms for storing the data on and reading the data from the container are described.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims benefit of U.S. Provisional Patent Application No. 60/712,315 filed on Aug. 30, 2005. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention  
         [0004]     The present invention relates to cleaning apparatus, such as machines for washing kitchenware or laundry; and in particular to systems for automatically dispensing chemicals used by such cleaning apparatus.  
         [0005]     2. Description of the Related Art  
         [0006]     Commercial kitchens have equipment to clean and sanitize glassware, dishes, silverware, pot, pans and cooking utensils, which are collectively referred to as “kitchenware.” Such equipment, commonly known as a “dishwasher” or more generically as a “warewasher”, has a cabinet defining an internal chamber into which trays of kitchenware are placed for washing. A washing and rinsing assembly within the chamber has a plurality of nozzles from which water sprays onto the kitchenware being cleansed. The lower part of the cabinet forms a reservoir that collects the water which is repeatedly circulated through the nozzles by a pump during the wash cycle. In a dump and fill system, the reservoir is drained after the wash cycle and refilled with fresh water for rinsing which then is pumped through the nozzles.  
         [0007]     At various times during the cleaning process, different chemicals are dispensed from supply containers into the warewasher. These chemicals may include a detergent, a rinse additive, and a sanitizer. Conventional warewashing equipment have separate receptacles for receiving these chemicals with each receptacle dedicated to only one type of chemical. For example, U.S. Pat. No. 6,322,242 discloses a dispensing system that has separate caps for chemical containers with supply lines running from each cap to the apparatus in which the chemicals will be used. Each cap and supply line is color coded to designate the type of chemical that is dispensed there through. Other types of marking have been used to indicate to employees which chemical container connects to each receptacle.  
         [0008]     Chemicals for use in automatic warewashing machines are available from many manufacturers. The same type of chemical, detergent for example, may vary in concentration depending upon the specific manufacturer and even the same manufacturer may produce the same chemical in different concentrations. A lesser amount of a more concentrated chemical is required during each operating cycle than a lesser concentrated version of the same chemical. Therefore the amount of a chemical to dispense into the warewasher can vary depending upon the particular brand of the chemical.  
         [0009]     Even with such location designations, employees still place the incorrect chemical in a particular dispenser location. This results in the wrong the chemical being dispensed at a particular time during the cleaning process. For example, a rinse additive might be dispensed in place of a detergent and thus the kitchenware is not properly cleaned.  
         [0010]     Therefore, there still exists a need for a control system that eliminates the possibility of dispensing an incorrect chemical into a cleaning apparatus.  
       SUMMARY OF THE INVENTION  
       [0011]     An apparatus is provided to dispense a plurality of chemicals into a cleaning machine. The chemicals are supplied in a plurality of containers each having data recorded thereon. The apparatus includes a plurality of dispenser ports for receiving chemicals from the containers and a plurality of flow control devices that govern the flow of chemicals from each dispenser port to the cleaning machine. A data reader arrangement obtains the data on the containers from which chemicals are received at each of the plurality of dispenser ports.  
         [0012]     A controller is connected to the plurality of flow control devices and to the data reader arrangement. The controller employs the data obtained from the containers to identify which of the plurality of ports received which of the plurality of chemicals. In response to a command to dispense a given chemical, the controller activates the respective flow control device which is associated with the dispenser port that received the given chemical. Thus a particular chemical can be received at any of the plurality of dispenser ports with the apparatus automatically knowing which port received which chemical.  
         [0013]     Various mechanisms can be used to record the data on the containers. In one case, the data are recorded as indicia on a label and the data reader arrangement optically senses the indicia. For example, the indicia may be a barcode that is read by a conventional barcode scanner. In another case, the data are recorded in a radio frequency tag on the container and the data reader arrangement interrogates the radio frequency tag to obtain the data. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is an isometric illustration of a commercial warewasher which incorporates the present invention;  
         [0015]      FIG. 2  is a partial sectional drawing showing connection of a chemical container to the dispenser of the warewasher;  
         [0016]      FIG. 3  is a schematic depiction of an optical system for reading indicia located on a chemical container;  
         [0017]      FIG. 4  illustrates a system for reading a barcode located on the chemical container;  
         [0018]      FIG. 5  is a schematic depiction of system for interrogating a radio frequency identification tag located on the chemical container;  
         [0019]      FIG. 6  is a schematically shows the warewasher control circuit; and  
         [0020]      FIG. 7  is a flowchart of a software routine that is executed by the control circuit to configure the warewasher operation to properly dispense each chemical. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     The present inventive dispensing system will be described in the context of a warewasher for cleaning kitchenware, however it should be appreciated that this dispensing system can be utilized with other types of cleaning equipment, such as apparatus for washing laundry, cleaning floors, and cleaning vehicles to name but a few examples.  
         [0022]     With initial reference to  FIG. 1 , a commercial kitchen warewasher  10  has a cabinet  12  defining a chamber into which kitchenware is placed for washing. Two side doors  13  and  14  are slidably mounted on the cabinet  12  to close openings through which racks of glasses, dishes, utensils, pot and pans pass into and out of the chamber. The side doors  13  and  14  are connected to a link arm  17  so that they operate in unison. The cabinet  12  contains standard washing and rinsing assembly that includes a plurality of nozzles  16  which spray water supplied by a pump  18 . A region at the bottom of the cabinet  12  forms a reservoir  15  into which the water drains from the kitchenware and which holds a volume of water.  
         [0023]     A dispensing system  20  is connected to the warewasher  10  to mete out different chemicals into the cabinet  12  at specific times during the cleaning process. The dispensing system  20  has a dispenser  21  that holds three containers  22 ,  23  and  24  that store a detergent, a rinse additive, and a sanitizer, for example. A different electrically operated pump is provided to feed each chemical from the respective container  22 ,  23  or  24  through supply tubes  29  to the warewasher cabinet  12 . Each container  22 ,  23  and  24  is inverted so that its neck  25  fits into a separate port  26 ,  27  and  28  of the dispenser  21  as shown in  FIG. 2  with respect to the first port  26  and first container  22 . Each container has a key  30  that fits into a keyway  31  of the respective dispenser port, thereby orienting the container so that an indicia  32  on the label faces a data reader  33 . It should be understood that the dispensing system  20  can utilize other forms of ports, such as for example the container caps with tubes shown in U.S. Pat. No. 6,322,242 or a reservoir that holds the chemical received from a container.  
         [0024]     A separate data reader  33 ,  34  and  35  is provided for each port  26 ,  27  and  28 , respectively to read data from the associated container and collectively form a data reader arrangement. The three data readers  33 - 35  are identical and an exemplary type of data reader is shown in  FIG. 3  as the first data reader  33 . In this case, the first container  22  has a label  80  with four areas  81 ,  82 ,  83  and  84  thereon, which may either be reflective or non-reflective to light. For example, each area may be printed with either white or black ink to define its reflectivity. The reflectivity of each of the four areas  81 - 84  is used to encode data regarding the particular container  22 , and specifically to identify the type of chemical contained therein. With four label areas  81 - 84 , sixteen different types of chemicals can be identified. Therefore, the indicia formed by the four label areas  81 - 84  can indicate not only the three chemical types (detergent, rinsing agent, or sanitizer), but other characteristic of the general chemical type, such as its concentration.  
         [0025]     The data reader  33  has four separate pairs  86 ,  87 ,  88  and  89  of light emitters  91  and detectors  92 . Each emitter-detector pair  86 - 89  is focused on a different one of the label areas  81 - 84 , respectively, to produce a signal that indicates the degree of reflectivity of the associated label, e.g. whether the area is white or black. For example, in the first emitter-detector pair  86 , the light emitter  91  transmits a beam  93  of light which is directed toward label area  84  on the container  22 . Depending on the reflectivity of the label area, the beam may be reflected back to the associated detector  92 . Even a black label area may reflect some light back to the associated detector. The emitter-detector pair may operate at a narrow band of wavelengths (for example in the infrared spectrum) to distinguish the sensing light from ambient light. The intensity of the reflected light is a function of the reflectivity of the associated label area  81 . Specifically, a white label area will reflect a greater amount of light than a black label area, thereby producing analog electrical signals of different magnitudes from the detector  92 . Therefore by comparing the signals from each light detector  92  to a threshold level, each analog signal is converted into a digital bit that indicates whether the associated label area is white or black. The four digital bits from the plurality of light detectors  92  of the data reader  33  designate the data about the chemical that is encoded by the indicia  32 , e.g. one of the sixteen chemical types. Because a black label area reflects some light, the failure of the detectors  92  to sense any reflected light indicates the absence of a container at that particular dispenser port.  
         [0026]     Where a need to encode a greater number of chemical types is required, other kinds of data recording mechanisms may be utilized. For example as shown in  FIG. 4 , a conventional barcode  94  can be utilized as the indicia  32  on container  22 . The barcode  94  can encode not only the type of chemical, but other information such as its manufacture date and concentration. In this embodiment, a standard barcode scanner  95  is employed as the first data reader  33 .  
         [0027]     There is a trend toward providing radio frequency identification tags on products, thereby enabling the products to be tracked during distribution from manufacturer to the ultimate consumer. Conventional radio frequency tags act as a transponder and respond to being interrogated by a radio frequency (RF) signal by producing a reply signal that carries information identifying the particular piece of merchandise. Such radio frequency identification tags can be utilized on the chemical containers  22 - 24  as the indicia  32  to identify the particular type of chemical contained therein, the concentration of that chemical, and other product information. As shown in  FIG. 5 , a radio frequency tag  96  is attached to the first container  22 . In this embodiment, the first data reader  33  comprises a conventional RF interrogator  97  that emits a radio frequency signal  98  that is directed toward the container  22 . In order to avoid cross-talk between the three data readers  33 - 35 , the transmitted radio frequency signal has a relatively low power so that it does not activate a tag on an adjacent container  23  or  24  within the dispensing system  20 . This ensures that the data being read will come from a container within the first dispenser port  26 . Upon receiving a signal at the proper frequency from RF interrogator  97 , the identification tag  96  returns a reply signal  99  that carries encoded information about the chemical within the first container  22  which the manufacturer stored in the tag. The radio frequency interrogator  97  receives and decodes that reply signal  99  to extract the encoded data.  
         [0028]     Referring to  FIG. 6 , the three data readers  33 - 35  are part of a control system  36  the governs the operation of the warewasher  10 . The control system  36  employs an electronic controller  37  that is based on a microcomputer  38  which executes a software control program stored in a memory  41 . The controller  37  includes input circuits  40  that receive signals from the data readers  33 - 35 . Input signals also are received from the operator control panel  39  that has switches by which the human operator starts a cleaning operation and selects operational functions to be performed. The control panel  39  also has devices that provide visual indications of the functional status of the warewasher. A modem  46  is connected to the microcomputer  38  for the exchange of data with other control systems and computers via a computer network  48 .  
         [0029]     The controller  37  has several output drivers  42 , one of which activates an annunciator  44 , such as a buzzer or a lamp which produce an audible or visible warning. Another output driver  42  operates a solenoid water valve  50  during the rinse cycle to send fresh water through the nozzles  16 . A manually operated supply valve  52  is provided to fill the reservoir  15  at the bottom of the cabinet  12  prior to operating the warewasher  10 . A drain valve  54  is electrically operated to empty the reservoir  15 . Another output of the controller  37  activates the pump  56  during the wash cycle. The controller  37  also automatically governs dispensing detergent and additives into the warewasher cabinet  12 . Specifically, the microcomputer  38  determines when to activate a detergent pump  58  in response to a signal from a conductivity sensor  59 , that is located below the water line of the reservoir  15 . Other output drivers  42  operate pumps  64  and  66  to introduce the rinse additive and the sanitizer chemicals into the warewasher cabinet  12  at appropriate times during the cleaning cycle. Alternatively the chemicals can flow to the warewasher cabinet by gravity in which case the dispenser pumps  58 ,  64  and  66  can be replaced by electrically operated valves to control that flow. Such dispenser pumps and valves are generically referred to as “flow control devices.” 
         [0030]     Several different types of sensors can be connected to the input circuits  40  of the controller  37 . A water temperature (WT) sensor  68  is located in the reservoir  15  to produce a signal indicating the temperature of the water. The controller  37  responds to that temperature signal by activating a water heater  70  that has a heating element within the reservoir. Another temperature sensor  72  is mounted in a conduit that carries water during the rinse cycle and thus provides an indication of the rinse water temperature (RT) to ensure that the proper water temperature is being maintained. If the rinse water is not at the proper temperature the controller  37  adds the sanitizer chemical from the dispensing system  20 . A pair of sensor switches (DR)  74  provide signals indicating when either side door  14  is open and the controller  37  suspends operation in those cases. A set of three sensors  75 ,  76  and  77  respectively detect when the chemical containers  22 ,  23  and  24  are empty.  
         [0031]     The present invention relates to a mechanism which dispenses chemicals from the dispenser  21  based on the information read from the data recorded on the containers  22 - 24  placed into the dispenser. Occasionally, the microcomputer  38  reads the data signals from the three data readers  33 - 35  to determine characteristics of the chemical at each dispenser port  26 - 28 . In the preferred embodiment, the data readers are polled each time a washing operation commences. However, in other cases, the signals from the data readers may be inspected by the microcomputer  38  whenever the operator changes a chemical container and presses a button on the dispenser  21  to indicate that event. In a system in which each dispenser port  26 - 28  has a reservoir that holds the chemical received from a container, the data reader scans the indicia when an operator fills the reservoir from the container.  
         [0032]     When it is desired to read the signals from the three data readers  33 ,  34  and  35 , the microcomputer  38  executes a software routine  100  depicted in  FIG. 7 . That routine commences at step  102  by setting a variable, designated a Port Pointer, to one to indicate the first port  26  of the dispenser  21 . Then, at step  104 , the microcomputer reads the signal from the data reader for the indicated port, at this time the first data reader  33 . The signal from that data reader is decoded at step  106  to extract the information indicating the type of chemical, e.g. detergent, rinsing agent or sanitizer, within the associated container. At step  108 , that chemical type designation is stored within a table in the memory  41  to provide an indication of the chemical available at the first dispenser port  26 .  
         [0033]     Next at step  110 , the microcomputer  38  determines the appropriate dose of this chemical to dispense during each operation of the warewasher. In one version of the present invention, the microcomputer  38  utilizes the indication of the particular type of chemical to address a look-up table within the memory  41  that contains a dose value for each commonly used type of chemical. For example, various types of detergent may require that different amounts be dispensed during each wash cycle of the warewasher  10 . Even the same general type of detergent may come in different concentrations, which also require that different amounts be dispensed for optimum cleaning and economy. The dose value preferably is defined by a particular amount of time that the pump  58  for the first dispenser port  26  should be operated in order to dispense the proper amount of chemical. Alternatively, for dispensing systems  20  that utilize a radio frequency identification tag  96  on the container, the information obtained from that tag may indicate not only the type of chemical, but also its physio-chemical parameters, such as viscosity, density, and concentration. The concentration is used to address in a look-up table to determine the pump operating time. In other situations, the control system  36  may be configured with the proper dispenser pump operating interval for a detergent, rinsing agent or sanitizer that has a predefined concentration. When the same general type of chemical is found with a different concentration, the microcomputer  38  executes a preprogrammed equation to derive the proper pump operating time for that different concentration, based on the pump operating time for the predefined concentration. In either situation, the appropriate pump operating time for the particular chemical in the container inserted in the first port  26  is then stored at step  112  as a the value of a dose variable for that port. This completes the configuration of the first port  26  with the type of chemical and the chemical dose.  
         [0034]     The software routine  100  then advances to step  114  at which the Port Pointer is incremented to read and process the indicia for the container in the next port. At step  116 , the program then returns to step  104  to process that data. When all three ports  26 - 28  have been configured in this manner, the software routine  100  terminates and normal washing operation of the warewasher  10  commences. At that time the memory  41  contains a designation of which port  26 - 28  contains each type of chemical (detergent, rinsing agent and sanitizer) and the pump operating time for that port.  
         [0035]     When the controller  37  gets to a point during the cleaning cycle at which detergent is to be dispensed into the cabinet  12 , the microcomputer  38  accesses the table within memory  41  that specifies the type of chemical inserted into each port  26 ,  27  and  28  of the dispenser  21 . Specifically, the microcomputer accesses a memory location that indicates the port into which a container of detergent has been inserted. That port designation determines which dispenser pumps  58 ,  64  or  66  to activate for the detergent. The table in memory  41  also specifies the amount of time that this pump should be operated to feed the proper dose of the detergent into the warewasher cabinet  12 . The microcomputer  38  then activates the respective dispenser pump for that prescribed period of time. A similar operation is conducted at the appropriate times during the cleaning cycle to dispense the rinsing agent and the sanitizer from the dispensing system  20 . Alternatively variable speed dispenser pumps  58 ,  64  or  66  could be employed and the dose of each chemical is controlled by varying the pump speed and thus the rate at which the chemical is supplied to the warewasher.  
         [0036]     Therefore, the present system properly dispenses the different chemicals regardless of into which port  26 ,  27  or  28  the operator has inserted a container of a particular chemical. In other words, unlike previous systems in which a particular port was designated to always receive a container of a given chemical, detergent for example, a particular chemical may be placed into any port and the operation of the machine is automatically reconfigured to properly dispense that chemical. The present dispensing system also detects when the same chemical is placed into more than one dispenser ports  26 - 28 , in which case the operator is alerted to that occurrence.  
         [0037]     Furthermore, if the signals from a data readers  33 - 35  indicate the absence of a particular chemical that is critical to proper cleaning, an alarm annunciation is issued. In addition, operation of the warewasher may be suspended by the controller  37  until a container of that chemical is inserted into the dispensing system  20 . It should be understood that not all of the different chemicals are essential to cleaning in all circumstances. A sanitizer typically only is required if the rinse water is below a defined temperature, e.g. 74° C., as water above that temperature will sanitize the kitchenware without requiring chemical augmentation. Therefore, operation of the warewasher  10  may continue after the supply of sanitizer is exhausted, as long as the rinse water is above the defined temperature.  
         [0038]     The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.