Abstract:
A conveyor warewasher includes at least one spray zone with multiple nozzles for spraying liquid onto wares passing therethrough, the spray zone including a tank for collecting sprayed liquid. The tank includes a drain outlet at the bottom of the tank for draining of the tank and a drain stop movable between a drain outlet closed position and a drain outlet open position. A drain control assembly includes a drain actuator operatively connected to cause movement of the drain stop between the drain outlet closed position and the drain outlet open position, and the drain actuator is moved by a powered device.

Description:
CROSS-REFERENCES 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/062,394, filed Oct. 10, 2014, the entirety of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This application relates generally to warewash machines and, more specifically, to a conveyor warewasher with an automated draining operation. 
       BACKGROUND 
       [0003]    Commercial warewashers of the conveyor-type (e.g., using a continuous conveyor with slots for wares or using a conveyor that reciprocates to moves wares through the machine in baskets) commonly include a housing area which defines washing and rinsing zones for dishes, pots pans and other wares. In certain zones, water is typically pumped from a tank through a pump intake, delivered to the wares via a spraying operation and then collected in the tank for re-use. In instances where the wash solution within a given tank becomes undesirably soiled, it may become necessary for the operator to manually drain the tank by lifting a drain lever to an open position until the wash solution drains out, then releasing the lever to refill the tank with water. This operation requires some time on the part of the operator, as the operator must remain in the vicinity of the tanks during the process. 
         [0004]    It would be desirable to provide a more operator friendly machine, enabling the operator to perform other necessary functions during a drain and refill process. 
       SUMMARY 
       [0005]    In one aspect, a conveyor warewasher includes at least one spray zone with multiple nozzles for spraying liquid onto wares passing therethrough, the spray zone including a tank for collecting sprayed liquid. The tank includes a drain outlet at the bottom of the tank for draining of the tank and a drain stop movable between a drain outlet closed position and a drain outlet open position. A drain control assembly includes a drain actuator operatively connected to cause movement of the drain stop between the drain outlet closed position and the drain outlet open position, and the drain actuator is moved by a powered device. 
         [0006]    In one implementation of the above aspect, the powered device is a solenoid actuator operatively connected to move the drain actuator. 
         [0007]    In one implementation of the above aspect, the powered device is a motor that rotates a cam member, which in turn engages the drain actuator. 
         [0008]    In one implementation of the above aspect, the machine includes an interface button for use in triggering operation of the powered device. In one example, the machine includes a controller responsive to actuation of the interface button to activate the powered device to move the drain actuator to a position corresponding to the drain stop in the drain outlet open position for a predetermined time period and, after the predetermined time period to activate the powered device to move the drain actuator to a position corresponding to the drain stop in the drain outlet closed position. 
         [0009]    In another aspect, a conveyor warewasher for washing wares includes a housing defining at least one spray zone for spraying liquid onto wares passing therethrough. A tank collects sprayed liquid, and includes a drain outlet. A drain stop is positioned in the tank and movable between a lowered drain outlet closed position and a raised drain outlet open position. The drain stop includes an upwardly extending overflow pipe through which excess liquid in the tank can flow to the drain outlet even when the drain stop is in the lowered drain outlet closed position. An automated drain control arrangement includes a drain actuator positioned to effect movement of the drain stop between the lowered drain outlet closed position and the raised drain outlet open position. 
         [0010]    In one implementation of the foregoing aspect, the automated drain control arrangement includes a linear actuator positioned for engaging the drain actuator. 
         [0011]    In one implementation of the foregoing aspect, the automated drain control arrangement include a rotatable cam member positioned for engaging the drain actuator during rotation. 
         [0012]    In one example of the foregoing implementation, the automated drain control arrangement includes a motor operatively connected to rotate the cam member. 
         [0013]    In one variation of the foregoing example, the automated drain control arrangement includes a controller operatively connected to effect operation of the motor, the controller configured to carry out a tank drain operation in which the cam member is rotated into a drain actuator lift position that causes the drain stop to move to the raised drain outlet open position. 
         [0014]    In one instance of the foregoing variation, during the tank drain operation the controller is configured to control the motor so as to maintain the cam member in the drain actuator lift position for a set time period, and to thereafter control the motor to move the cam member to a drain actuator drop position that enables the drain stop to move to the lowered drain outlet closed position. 
         [0015]    In one implementation of the foregoing aspect, the automated drain control arrangement includes a controller operatively connected to effect movement of the drain actuator, the controller configured to carry out a tank drain operation in which the drain stop is moved to the raised drain outlet open position. 
         [0016]    In one example of the foregoing implementation, during the tank drain operation the controller is configured to maintain the drain stop in the raised drain outlet position for a set time period, and to thereafter effect movement of the drain stop to the lowered drain outlet closed position. 
         [0017]    In one variation of the foregoing example, the controller is configured to effect refill of the tank after the drain stop has been moved to the lowered drain outlet closed position. 
         [0018]    In one variation of the foregoing example, the controller is configured to initiate the tank drain operation in response to operator actuation of an interface button. 
         [0019]    In one variation of the foregoing example, the controller is operatively connected to effect movement of the drain actuator through one of (i) a motor and rotatable cam member or (ii) a solenoid operated linear actuator. 
         [0020]    The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a schematic depiction of one embodiment of a conveyor warewasher; 
           [0022]      FIG. 2  is partial perspective view of a tank drain arrangement; 
           [0023]      FIGS. 3-5  are partial perspective views of operation of the tank drain arrangement; 
           [0024]      FIG. 6  is a partial perspective view of a variation of the tank drain arrangement; and 
           [0025]      FIG. 7  is a perspective view of another embodiment of a conveyor warewasher. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Referring to  FIG. 1 , an exemplary conveyor-type warewash system, generally designated  10 , is shown. Warewash system  10  can receive racks  12  of soiled wares  14  from an input side  16  which are moved through tunnel-like chambers from the input side toward a dryer unit  18  at an opposite end of the warewash system by a suitable conveyor mechanism  20 . Either continuously or intermittently moving conveyor mechanisms or combinations thereof may be used, depending, for example, on the style, model and size of the warewash system  10 . The conveyor machine includes multiple spray zones for cleaning the wares passing therethrough. In the illustrated embodiment, the racks  12  of soiled wares  14  enter the warewash system  10  through a flexible curtain  22  into a pre-wash chamber or zone  24  where sprays of liquid from upper and lower pre-wash manifolds  26  and  28  with spray nozzles  27  and  29 , above and below the racks respectively, function to flush heavier soil from the wares. The liquid for this purpose comes from a tank  30  via a pump  32  and supply conduit  34 . As will be described below, a drain system  120  provides a single location where liquid is pumped from the tank  30  using the pump  32  and where liquid can be drained from the tank, for example, for a tank cleaning operation. 
         [0027]    The racks proceed to a next curtain  38  into a main wash chamber or zone  40 , where the wares are subject to sprays of cleansing liquid from upper and lower wash manifolds  42  and  44  with spray nozzles  47  and  49 , respectively, these sprays being supplied through a supply conduit  46  by a pump  48 , which draws from a main tank  50 . A heater  58 , such as an electrical immersion heater provided with suitable thermostatic controls (not shown), maintains the temperature of the cleansing liquid in the tank  50  at a suitable level. Not shown, but which may be included, is a device for adding a cleansing detergent to the liquid in tank  50 . During normal operation, pumps  32  and  48  are continuously driven, usually by separate motors, once the warewash system  10  is started for a period of time. 
         [0028]    The warewash system  10  may optionally include a power rinse chamber or zone (not shown in  FIG. 1 ) that is substantially identical to main wash chamber  40 . In such an instance, racks of wares proceed from the wash chamber  40  into the power rinse chamber, within which heated rinse water is sprayed onto the wares from upper and lower manifolds. 
         [0029]    The racks  12  of wares  14  exit the main wash chamber  40  through a curtain  52  into a final rinse chamber or zone  54 . The final rinse chamber  54  is provided with upper and lower spray heads  56 ,  58  (with respective nozzles) that are supplied with a flow of fresh hot water via pipe  60  under the control of solenoid valve  62 . A rack detector  64  is actuated when a rack  12  of wares  14  is positioned in the final rinse chamber  54  and through suitable electrical controls, the detector causes actuation of the solenoid valve  62  to open and admit the hot rinse water to the spray heads  56 ,  58 . The water then drains from the wares into tank  50 . The rinsed rack  12  of wares  14  then exit the final rinse chamber  54  through curtain  66 , moving into dryer unit  18 , and eventually out of the machine. 
         [0030]    A machine controller  200  and user interface  202  are shown schematically in  FIG. 1 . The term controller as used herein is intended to broadly encompass any circuit (e.g., solid state, application specific integrated circuit (ASIC), an electronic circuit, a combinational logic circuit, a field programmable gate array (FPGA)), processor (e.g., shared, dedicated, or group—including hardware or software that executes code) or other component, or a combination of some or all of the above, that carries out the control functions of the machine or the control functions of any component thereof. The user interface  202  may, by way of example, be a touch screen display (e.g. capable of presenting user actuatable buttons), a regular display in combination with one or more keys or buttons, a set of buttons and one or more indicator lights, or combinations of any of the foregoing. 
         [0031]    Many variations of conveyor warewash devices are possible, the foregoing being merely one example. 
         [0032]    Referring now to  FIG. 2 , a drain system for a tank of such machine includes a standpipe  130  that supports a strainer  132  thereon. The standpipe typically sits down in a well and has a lower drain plug portion that can be positioned within the well so as to block a drain port in the well. The drain plug portion may include a tapered end that is used to guide the drain plug portion into the drain port. The standpipe  130  includes an opening at its upper end and passing down through the standpipe to the lower end. A deflector  141  may be included that is connected at the upper end to the standpipe  130 . The deflector  141  is spaced from the upper end to allow liquid to pass therebetween during an overflow condition, in which case such overflowing liquid travels down internally within the standpipe to and out of the drain port. The deflector  141  prevents large food particles and tableware (or other objects) from entering the opening of the standpipe. 
         [0033]    A drain actuator (here a lift linkage system)  140  is provided for use in lifting and lowering the standpipe  130 . The drain actuator  140  includes a support bracket  142  that is mounted on an upper surface  144  of a pump housing  146 . The support bracket  142  slidably supports a moveable member  148  that includes a pair of L-shaped slots  150  and  152  within which fasteners  154  and  156  are received. The moveable member  148  includes an engageable end  160  that includes a graspable portion  162  (or lever) that can be grasped and pulled by an operator to lift the moveable member and pull the moveable member toward the operator. Due to the L-shape of the slots  150  and  152 , the moveable member  148  can remain in the raised position until a horizontal force is applied thereto. The moveable member  148  is operatively connected to a connector  164  that connects the standpipe  130  to the moveable member. In particular, the connector  164  is illustrated as being releasably engaged with the deflector  141 , however, other configurations are possible. Further details are described in U.S. Pat. No. 8,252,121, which is incorporated herein by reference. 
         [0034]    Referring now to  FIGS. 3-5 , the movement of the movable member of the drain lift linkage may also be controlled by an associated actuator. In this embodiment, a cam member  180  is rotatable by a motor (represented schematically as  182 ) such as a stepper motor or servo motor. The cam member may be rotatable by a shaft  181  that passes through the machine housing. In  FIG. 3  the lever  162  of the movable member  160  is in the lowered position and in  FIG. 4  the lever  162  has been moved to the raised position (for draining) by clockwise rotation of the cam member  180 , the cam surface  186  of which slides across and relative to the lever  162  as the lever is raised. The cam member  180  is held in the position of  FIG. 4  for a time period suited for draining (e.g., a set time period or a time period that ends upon sensing of drain completion), and then the cam member  182  is rotated clockwise to be clear of the lever  162 , allowing the lever to release and fall back down (to stop draining) as reflected in  FIG. 5 . In this regard, the slots  150  and  152  may be shaped to permit such drop without requiring any horizontal shift of member  148 . 
         [0035]    Of course, it is recognized that other mechanisms could be used to raise and lower the lever  162 , such as a solenoid operated device. For example,  FIG. 6  depicts a potential arrangement using a linear actuator  190  with associated solenoid  192  to raise and lower the lever  162  of the movable member  160 . Notably, in the case of both the cam member arrangement and the linear actuator arrangement, the lever  162  can still be manually moved by an operator of needed. 
         [0036]    Through use of these arrangements (e.g.,  FIGS. 3-5  or  FIG. 6 ), the draining and filling processes of a machine may be automated, providing operators some flexibility to save time by pressing a button for the draining and filling processes to take place in the absence of the operator while the machine gets ready for the next cleaning cycles. Operators are able to perform other tasks while the machine goes through the draining and filling process unmanned, getting the machine ready for the subsequent cycles. 
         [0037]    An exemplary sequence of operation of automatic machine draining and refilling may include an operator pressing a button (e.g., a control button associated with a machine user interface, such as interface  202  depicted in  FIG. 7 ) or taking some other actuation to trigger the drain. The machine controller is configured to control the components in response to the trigger. Thus, the machine controller  200  activates the powered device (e.g., the solenoid  192  or motor  182 ) to lift the drain lever  162  to an open position (e.g., per  FIG. 4 ) to drain the machine tank. Such lift and drain may, for example, be for a predetermined time period known to be sufficient to allow complete draining. In some embodiments the predetermined time period may be adjustable by the operator (e.g., via the user interface  202 ), so as to enable either full or partial draining. After the predetermined time period, the powered device finishes its cycle to release or otherwise permit lowering of the drain lever  162  to the closed position (e.g., per  FIG. 3 ), and refill of the machine tank is initiated (e.g., by opening a valve). After refill the machine would then automatically reheat water to a set temperature to make the machine ready for operation. 
         [0038]    In one example of a more advanced arrangement, the operator may press the button to trigger drain and refill at any time (e.g., even during an ongoing machine cleaning operation) and the machine will identify (e.g., via controller  200  configuration and use of sensors such as rack detector  64 ) when the machine is empty of wares. Only then would the controller initiate the automated drain and refill process. In another example of a more advanced arrangement, the controller  200  may keep track of the duration of machine operation since the last drain and refill occurred and initiate an alert (e.g., a drain alert indicator light of the user interface  202 ) after a predetermined amount of operating time so that the operator knows it may be time to initiate the automated drain and refill. 
         [0039]      FIG. 7  shows another machine incorporating the automated drain and fill arrangement, as well as a controller  200 ′ of such machine, and associated user interface  202 ′. 
         [0040]    It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible.