Abstract:
A drip tray sanitizing system includes a pump connectable to a sanitizer solution container and a valve connectable to a diluent source. A spray manifold disposed in the drip tray receives a mixture of the two streams and sprays the mixture into the drip tray in a prescribed routine to produce a sanitizing or cleansing effect. Methods for using the drip tray sanitizing system include manual, semi-automatic, and automatic sanitizing, as well as manual and automatic rinsing. The semi-automatic and automatic sanitizing routines require the use of a controller. Use of this apparatus in a product dispenser may widen the range of products and product concentrates available for use with a product dispenser.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to product dispensers, and more particularly to, but not by way of limitation, to a method and apparatus for sanitizing or cleansing a drip tray of a product dispenser. 
   2. Description of the Related Art 
   Product dispensers on the market typically are sold with a drip tray and a cup rest attached. The drip tray serves as a safeguard to catch and control overspray and overfill of product. The drip tray also ends up as a disposal site for unwanted drinks, unwanted ice and in cases where the dispenser is not producing the product in the right proportions, bad dispenses. 
   Two types of drip trays exist, draining and non-draining. Draining drip trays are typically hard-plumbed to the drain lines of a building. The non-draining drip trays are not plumbed and must be emptied on a regular basis, or immediately when full. For this reason, drip trays on product dispensers with shelf stable products are usually installed with a hard mounted drain. The installed drain enables the users to dispose of items through a hard-plumbed, permanent sewer disposal system, thereby avoiding the mess associated with overflowing of the non-draining drip tray. 
   In some cases, where it would be unpleasant for the product or product concentrate spills to sit in the drip tray for extended periods, the drip trays are removable, thereby forcing the operators to clean the drip trays daily. Problems with this situation arise when operators do not clean the drip trays on a regular basis. For example, uncleaned drip trays in citrus dispensers can attract fruit flies, as well as cause unpleasant odors or bacterial growth. 
   Still another level of cleanliness is required for products that belong to the dairy family. Milk or milk concentrate will spoil quickly if a remnant is left exposed in a drip tray or even a drain. Spoiled milk or dairy products around a dispenser can cause foul odors, be unsightly, and promote bacterial growth. Milk dispensers on the market typically do not have more than a catch basin, if they have any sort of drip tray at all. Accordingly, a sanitizing system for a drip tray would be both beneficial and effective in promoting a cleaner product dispenser and surrounding environment. 
   SUMMARY OF THE INVENTION 
   The present invention is a sanitizing system for a product dispenser similar in type, but not exclusive to the product dispenser disclosed in U.S. Pat. No. 6,568,565, which issued on May 27, 2003. In this filing, a drip tray sanitizing system includes a valve, a pump and a spray manifold used to deliver a sanitizing mixture or a diluent to a drip tray of a product dispenser. The sanitizing mixture or diluent is sprayed in a shape complementary to the inner chamber of the drip tray for a predetermined interval. The drip tray sanitizing system may further include a controller to conduct the cleansing or rinsing routines automatically or semi-automatically. The drip tray sanitizing system may be implemented in new production or may be retrofit into existing product dispensers. 
   A method of sanitizing the drip tray includes pumping sanitizing solution from a package, mixing the dispensed sanitizing solution with diluent, and dispensing the mixed solution through a spraying apparatus into the drip tray in a prescribed pattern to produce a cleansing or sanitizing effect. 
   A second method includes using the drip tray sanitizing system to rinse the drip tray. In this case, sanitizer is not delivered to the drip tray. Further derivations of the methods include sanitizing the drip tray and/or rinsing automatically through the use of the controller and a software activation routine. With this type of control scheme, the sanitizing and the rinsing may be activated in a timed fashion to optimize the cleansing effect. 
   It is therefore an object of the present invention to provide a system for delivering a sanitizing mixture or a diluent into a drip tray to produce a cleansing or sanitizing effect. 
   It is further an object of the present invention to provide a drip tray sanitizing system that automatically conducts a sanitizing or rinsing routine through the use of a real time clock. 
   It is still further an object of the present invention to provide a beverage dispenser with a drip tray sanitizing system. 
   Still other objects, features, and advantages of the present invention will become evident to those of ordinary skill in the art in light of the following. Also, it should be understood that the scope of this invention is intended to be broad, and any combination of any subset of the features, elements, or steps described herein is part of the intended scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view illustrating the components of a sanitizing system according to the preferred embodiment. 
       FIG. 2   a  is a perspective view of a product dispenser with a self-sanitizing drip tray. 
       FIG. 2   b  is a side view and a cut away of a product dispenser with a self-sanitizing drip tray. 
       FIG. 3   a  is a block diagram of a control system associated with a method of manually sanitizing a drip tray. 
       FIG. 3   b  is a method flowchart for a manual sanitize routine. 
       FIG. 3   c  is a block diagram of a control system associated with a semi-automatic or automatic sanitizing system for a drip tray. 
       FIG. 3   d  is a method flowchart for semi-automatically sanitizing a product dispenser drip tray. 
       FIG. 3   e  is a method flowchart for automatically sanitizing a product dispenser drip tray. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. It is further to be understood that the figures are not necessarily to scale, and some features may be exaggerated to show details of particular components or steps. 
   A method and apparatus are used to sanitize a product dispenser drip tray. The apparatus includes a spray manifold disposed in the drip tray of a product dispenser. The present invention is a sanitizing system for a product dispenser similar in type, but not exclusive to the product dispenser disclosed in U.S. Pat. No. 6,568,565, which issued on May 27, 2003. In this filing, a sanitizing system includes a drip tray with a drain, a cup rest, a spray manifold, a pump that draws sanitizer fluid from a sanitizer solution container, a water valve, a backflow prevention device, and, if desired, a control system that activates and deactivates the system in a prescribed routine to produce a cleansing or sanitizing effect in the drip tray. A method of sanitizing the drip tray includes pumping a sanitizing solution from a package, mixing the dispensed sanitizing solution with a diluent, and dispensing the mixed solution through a spraying apparatus into the drip tray. 
   As illustrated in  FIGS. 1-3 , a drip tray sanitizing system  100  includes a spray manifold  130 , a pump  140 , a sanitizer container  160 , and a valve  165 . The pump  140  includes an inlet port  178  and an outlet port  179 . The inlet port  178  is coupled to a tubing adapter  175  having a first end  176  and a second end  177 . The first end  176  includes a smooth outer face to mate with an o-ring (not shown), thereby creating a sealed passage. The second end  177  is a barb fitting, commonly used in the industry, for mating with flexible tubing. The second end  177  of the tubing adapter  175  is connected to a first end  174  of a flexible tubing, herein known as a first sanitizer supply line  148 . A second end  173  of the first sanitizer supply line  148  adapts to an outlet port  151  of a quick disconnect connector  150 . The inlet port  152  of the quick disconnect connector  150  is suitable for mating with an outlet port  163  of the sanitizer container  160 . While this quick disconnect connector  150  has been shown with o-rings, one skilled in the art will recognize that any suitable type of quick disconnect may be used to accelerate changeout of the container  160 . 
   The outlet port  179  of the pump  140  is connectable to a first end  276  of a second adapter  275 . A second end  277  of the second adapter  275  is connectable to an inlet port  154  of a second sanitizer supply line  144 . An outlet port  155  of the second sanitizer supply line  144  is connectable to a second inlet port  186  of a mixing union  145 . 
   The valve  165  is a solenoid-operated valve, and includes an inlet port  168  and an outlet port  167 . The inlet port  168  of the valve  165  attaches to an outlet port  172  of a backflow prevention device  170  or may attach to a diluent supply tube, depending upon installation constraints. The backflow prevention device  170  further includes an inlet port  171  that is plumbed to a diluent source. The backflow prevention device  170  separates the fluid system from a public water system. As such, the diluent may flow from the inlet port  171  to the outlet port  172  of the backflow prevention device  170 , but cannot flow in the reverse direction to the supply. 
   The outlet port  167  of the valve  165  is adapted to mate with a first end  182  of a tubing adapter  180 . The tubing adapter  180  includes a second end  181  having a barb fitting for coupling with flexible tubing. The second end  181  of the adapter  180  connects to a first end  183  of a diluent supply tube  146 . The diluent supply tube  146  further includes a second end  184  that is adaptable to a first inlet port  185  of the mixing union  145 . The mixing union  145  further includes an outlet port  187 . 
   The outlet port  187  of the mixing union  145  is coupled to an inlet port  188  of a mixture tube  138 . An outlet port  189  of the mixture tubing  138  is coupled to an inlet port  190  of a removable fitting  135 . The removable fitting  135  includes an outlet port  191  suitable for mating with an inlet port  192  of the spray manifold  130 . In this preferred embodiment, the structure includes o-rings, a bore, and a lockplate  195  to secure the removable fitting  135  to the spray manifold block  130  and maintain a seal. While this preferred embodiment has been shown with o-rings, any suitable means may be used to provide the ability to remove and reinstall the fitting  135  in the spray manifold  130 . 
   The spray manifold  130  includes the inlet port  192 , an inner passage  196 , spray ports  193 , and a groove  194 . The inner passage  196  is contained within the confines of the spray manifold  130 , and can be accessed through the inlet port  192 . The spray ports  193 , located in a predetermined pattern on a first side  197  and a second side  198  of the spray manifold  130 , pass through to the inner passage  196 , thereby providing multiple exit ports for fluids entering through the inlet port  192 . It should be understood by those of ordinary skill in the art that the spray ports  193  may be located on the spray manifold  130  on only one side and in any pattern. The alignment groove  194  is located parallel to the first and second sides  197  and  198  of the spray manifold  130  to provide alignment aid upon installation. 
   The mixing union  145  allows the sanitizing fluid and the diluent streams to merge before entering the spray manifold  130 . Although this preferred embodiment includes the mixing union  145 , mixing may be accomplished through other means or in varying components. Illustratively, the sanitizing fluid stream and the diluent stream may each be input separately into the spray manifold  130  or the fluid paths may be joined through a standard tee connection. 
   As shown in  FIG. 2   a , a product dispenser  200  includes a drip tray  101  with a drain  105 , and a cup rest  125 . The drip tray  101  is typically removable for cleaning. The cup rest  125  fits into the drip tray  101 , thereby providing a level surface for cups to rest on while being filled. The drain  105 , when connected to a suitable sewage disposal system, allows for easy disposal of drip tray food contents and cleansing fluids. 
   As shown in  FIG. 2   b , the product dispenser  200  may be outfitted with a drip tray sanitizing system  100 . The drip tray sanitizing system  100  may be retrofit into existing product dispensers or may be installed as a new production feature. In use, the spray manifold  130  must be disposed inside of the drip tray  101 , beneath the cuprest  125  to refrain from impacting a user interface area. The remainder of the components, including the mixing union  145 , the valve  165 , and the pump  140  may be located remotely from the spray manifold  130 , as required, depending upon dispenser design constraints and installation conditions. 
   Optimally, the sanitizing system lines would be located within the confines of the product dispenser  200 , with an access port providing an entrance for the diluent source line and the sanitizer line  148 . The sanitizer container  160  may be located remote from the pump  140 . The sanitizer container  160  should be located in an easily accessible location to facilitate the changing of the container  160 . Illustratively, the sanitizer container  160  could be stored in a hanging position on a backside of the dispenser  200 , underneath the product dispenser  200 , or beneath a countertop. The container  160  in this preferred embodiment is a disposable container for ease of use. However, one skilled in the art will recognize that the container may be of the refillable type to reduce sanitizer packaging costs. 
   The drip tray sanitizing system  100  may further include a pump switch  141  and a valve switch  166  as shown in  FIG. 3   a  for activation by an operator. Power is supplied from the power supply  161  to the pump  140  and the valve  165  when the switches  141  and  166  are depressed. The switches  141  and  166  may be activated manually by an operator to provide power to the pump  140  and the valve  165 . 
   In operation, when the pump  140  is powered, the sanitizing fluid located in the sanitizer container  160  is suctioned out of the container outlet  163 , through the quick disconnect connector  150 , through the sanitizer supply tube  148 , through the adapter  175  to the inlet port  178  of the pump  140 . The sanitizer fluid passes through the pump  140  and exits the pump outlet  179 . Once out of the pump  140 , the sanitizer fluid is forced through the second adapter  275 , and then through the high pressure sanitizer line  144  to the second inlet port  186  of the mixing union  145 . 
   The diluent from the diluent source enters the sanitizing drip tray control system through the inlet port  171  of the backflow prevention device. Pressure from the diluent source forces the diluent through the backflow prevention device  170 , and into the inlet  168  of the valve  165 . The diluent flow stops at the valve  165  when the valve  165  is in a closed position. When powered, the valve  165  is in an open position, and the diluent flows therethrough. Once the diluent exits the outlet port  167  of the valve, it flows through the adapter  180 , and through the diluent tube  146 , thereby entering the first inlet port  185  of the mixing union  145 . 
   The sanitizer fluid and the diluent streams merge in the mixing union  145  and exit the outlet port  187 . The mixture then moves through the mixture tube  138 , through the removable fitting  135 , and into the inlet  192  of the spray manifold  130  when the pump  140  is on and the valve  165  is in the open position. The mixture continues past the inlet port  192  and enters the inner passage  196 , where it is forced to exit through the plurality of smaller diameter outlet ports  193 . The smaller diameter outlet ports  193  force the fluid to exit in a jet stream, thereby creating a predetermined spray pattern complementary to the inner envelope of the drip tray  101 . The mixture is sprayed into the drip tray  101  until the pump  140  and the valve  165  are de-energized. Excess fluid will drain out of the drip tray  101  through the drain port  105  to a suitable disposal. 
     FIG. 3   b  provides a method flowchart for manually conducting a drip tray sanitizing operation in a product dispenser  200 . The process commences with step  10 , wherein an operator activates the pump switch  141  and the valve switch  166  to provide power to the pump  140  and the valve  165 , respectively, step  15 . The process continues with step  20 , wherein the pump  140  displaces the sanitizer fluid and the valve  165  opens to allow the diluent to flow past the valve  165 . Both the sanitizer fluid and the diluent flow to the spray manifold  130  and are sprayed into the drip tray  101 , step  25 . The mixture continues to flow until the switches are deactivated in step  30 . 
   While the manual process has been shown with both the valve switch  166  and the pump switch  141  being activated, one skilled in the art will recognize that only one switch may be activated to allow for either a sanitizing fluid only or a diluent only flow. The use of a sanitizing fluid only flow would be beneficial in providing a higher concentration of sanitizing fluid in the drip tray  101 . The use of a diluent only flow is beneficial to provide a rinsing function in the drip tray  101 , thereby decreasing amount of sanitizing fluid used in a given time interval. As such, the operator may alternate between rinsing and sanitizing the drip tray  101  on a personal preference basis. 
   Alternatively, a controller  162 , which may be any suitable control device such as a microprocessor or microcontroller, may be employed to provide the switching as shown in  FIG. 3   c . The use of a controller  162  provides the capability to semi-automatically or automatically conduct all or some of the drip tray sanitizing operations. The controller  162 , the power supply  161 , and the switches  141  and  166  may be packaged as a standalone control system for the drip tray sanitizing system  100  or may be fully integrated into an existing electronic control system of the product dispenser  200 . 
     FIG. 3   d  provides a method flowchart for semi-automatically sanitizing a drip tray  101 . In this embodiment, the process is still initiated by an operator, but the remainder of the process is conducted by the controller  162 . The process begins with step  35 , wherein the controller  162  is in a wait state. The controller  162  then moves to step  40 , wherein it determines whether a start signal has been received by the operator. If a start signal has not been received, the process returns to the wait state in step  35 . If a start signal has been received in step  40 , then the process moves to step  45 , wherein the controller  162  activates the pump switch  141  and the valve switch  166 . Once activated, power is transferred to the pump  140  and the valve  165 . 
   The pump  140  siphons the sanitizer fluid from the sanitizer container and the valve  165  moves to an open position, thereby allowing the sanitizing fluid stream and the diluent stream to move towards the mixing union  145 . The diluent stream and the sanitizing fluid stream merge in the mixing union  145 , and are allowed to mix. The controller  162  continues to energize the switches  141  and  166  for a predetermined interval, thereby allowing the sanitizing mixture to move through the spray manifold  130 , and into the drip tray  101 . At the end of the predetermined interval, ten seconds in this preferred embodiment, the controller  162  deactivates the switches  141  and  166  to stop the flow of the sanitizing fluid, the diluent, and ultimately, the sanitizing mixture, step  55 . Next, the controller  162  determines if a stop signal has been received, step  60 . If a stop signal has been received the process moves to step  65 , the end. If a stop signal has not been received in step  60 , the controller  162  returns to step  35  to await another start signal. The sanitizing mixture pools in the drip tray  101  to provide a sanitizing effect, and then moves down the drain, thereby sanitizing the drain line. 
   Similar to the manual process previously disclosed, the semi-automatic process may further include a rinse only function. The semi-automatic rinse process is virtually identical to the method of  FIG. 3   d , except that the controller  162  activates and deactivates only the valve switch  166  in steps  45  to step  55 . The ability to only use the diluent provides additional cost savings through reduced sanitizer fluid or sanitizer fluid concentrate. In this arrangement, the operator has the ability to determine the level of cleansing required. 
   In a fully automatic embodiment, the controller  162 , having a real-time clock, conducts all of the sanitizing operations for the product dispenser  200 . The method flowchart of  FIG. 3   e  illustrates the fully automatic process. In the fully automatic process, the controller  162  activates and deactivates the valve switch  141  and the pump switch  166  at predetermined intervals from initialization of the product dispenser  200  to control the flow of fluids to the spray manifold  130  and drip tray  101 . In this arrangement, the controller  162  may be programmed to conduct a cleansing routine on a scheduled basis, illustratively, every fifteen minutes or on the hour. Further advantages of this type of arrangement include the ability to alternate between the sanitizing routine and the rinsing routines to minimize the unnecessary use of sanitizing fluid. The length of the cleansing routine may also be customized to tailor the sequence to a specific product type. 
   The process begins with step  70 , wherein the product dispenser  200  and the controller  162  are initialized. The controller  162  proceeds to a wait state, as shown in step  72 . The controller  162  then moves to step  74 , wherein the controller  162  determines whether a start signal has been received. If a start signal has not been received, the process returns to step  72 , the wait state. If a start signal has been received, the controller  162  moves to step  76 , wherein the controller  162  determines if the start signal is for a sanitize routine or a rinse routine. If the start signal is for a sanitize routine, the process moves to step  78 , wherein the controller  162  activates the valve switch  166  and the pump switch  141 , thereby allowing the sanitizer fluid and the diluent to flow to the spray manifold  130 . 
   The valve switch  166  and the pump switch  141  are activated for a predetermined interval, ten seconds in this preferred embodiment, to allow the mixture to spray the inside of the drip tray  101 . After the predetermined interval, the controller  162  moves to step  82 , wherein it deactivates the switches  141  and  166  to cease the flow of fluids to the drip tray  101 . If the start signal in step  76  was not for a sanitize routine, then the process moves to step  80 , wherein the controller  162  activates only the valve switch  166  for the predetermined interval, thereby commencing a rinse routine. Upon ending the activation time, the process moves to step  82 , wherein the controller  162  deactivates the switches to cease the flow of fluids to drip tray  101 . In step  84 , the controller  162  determines if a stop signal has been received. If a stop signal has been received, the process moves to step  86 , where the process ends. If a stop signal has not been received, the process returns to step  72 , the wait state, such that the controller  162  may continue to monitor for start signals. 
   The fully automatic process has been shown to accommodate a rinse cycle to minimize the use of the sanitizer fluid or fluid concentrate. It should be clear to one skilled in the art the controller  162  has control of the valve switch  166  and the pump switch  141  to conduct any rinsing or sanitizing functions. It should also be clear that a set of manual override switches may be included for use in an on demand type if arrangement, thereby allowing the operator to conduct an unscheduled cleansing operation. 
   While this process has been shown to hinge on the initialization of the product dispenser  200 , it should be clear to one skilled in the art that the controller  162  may use an actual time as an activation point for the commencement of the a sanitizing routine; illustratively, on the hour, store closing time, store opening time, etc., to remove the possibility of missed cleansing cycles. 
   Although the present invention has been described in terms of the foregoing preferred embodiment, such description has been for exemplary purposes only and, as will be apparent to those of ordinary skill in the art, many alternatives, equivalents, and variations of varying degrees will fall within the scope of the present invention. That scope, accordingly, is not to be limited in any respect by the foregoing detailed description; rather, it is defined only by the claims that follow.