Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a division of U.S. patent application Ser. No. 10/613,973, filed on Jul. 3, 2003, now U.S. Pat. No. ______ issued on ______, priority from which is hereby claimed. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to dispensers for consumable liquids, and more particularly to a dispenser that delivers consumable liquid from a container at one location, through a flow path to a dispensing location.  
       BACKGROUND OF THE INVENTION  
       [0003]     Often, in the past, consumable liquid dispensers for delivering, for example, cream or milk to a consumer&#39;s coffee or tea has relied on gravity flow downward from a container to a dispensing location. This has meant that such dispensers were typically located entirely above a counter. These dispensers use valuable above-counter space that could be put to better use. The dispensing unit has to be large enough to house one or more containers of significant size. In addition refrigeration of the above-counter container or containers (essential for dairy products) further adds to the size of the above-counter unit.  
         [0004]     Liquid consumables that are delivered under pressure such as beer or carbonated water can be remotely housed and delivered to a tap or dispenser at a bar or counter where drinks are prepared. Non-carbonated drinks like cream, milk and fruit juice have ordinarily not been delivered to a dispensing station in this manner. Beer is delivered to a remote tap by compressed air forced into direct contact with the beer in a keg. Where spoilage is a concern one would ordinarily like to avoid air contact with the liquid.  
         [0005]     Non-carbonated liquid can be moved from one place to another by a pump. However, where the liquid is consumable (i.e. a food product), that raises concerns for sanitation. Pump parts that contact liquid require constant, repeated cleaning to maintain proper sanitary conditions.  
         [0006]     There is a need, therefore, for a consumable liquid delivery system that does not require extensive counter space, that works to deliver non-carbonated liquids from a remote location, that does not contact the liquid with any movable part as would a pump and that moves the liquid other than by gravity.  
         [0007]     Where, as in the case of dairy products, temperature of the consumable liquid is an important consideration, a further problem must be addressed. That problem is maintaining temperature of the liquid product in the path from its container or “store” to its dispensing location. For dairy products close temperature control at all points along the delivery system is a government requirement. In the U.S. dairy product must be maintained at a temperature above 32° and below 41° Fahrenheit within its container and along the length of the delivery tube.  
         [0008]     A shortcoming of known dispensers of consumable liquids such as cream is lack of a consistent dose from one dispenser use to the next. In certain environments this is undesirable. Proprietors of many convenience stores and fast food restaurants where consumers operate the cream dispensers would prefer to know that each activation of the dispenser will provide the same dose. This is also true where an employee provides a beverage at a drive-through window. It is preferable for coffee with cream, for example, to be consistent from one restaurant to the next. Travelers that patronize chain restaurants often do so in the expectation that products they purchase will be virtually identical at each restaurant. So a consistent dose of cream, half and half or milk with every cup of coffee or tea is desirable.  
       SUMMARY  
       [0009]     In accordance with this invention, a dispenser for consumable liquids delivers the liquid to a dispensing location from a remote store or container without reliance on gravity flow, without introducing air or other gas under pressure into contact with the liquid and without contacting the liquid with any moving part of a pump or the like. The mechanism for delivery of the liquid is gas pressure activated. In the preferred embodiment it is an inflatable bladder or air bag that engages a collapsible container such as a compressible bag containing the liquid. Compressed air is fed to the inflatable bladder, which is confined in its position in force exerting contact with the flexible, liquid-containing bag. The compressible bag opens to a liquid delivery path leading to the dispensing location. Preferably the path contains a flexible tube through which the liquid flows. In a preferred embodiment, flow is controlled by a pinch valve normally pinching the tube closed. Preferably both the flexible bag and the flexible liquid delivery tube are relatively inexpensive and can be discarded after the bag is exhausted of liquid. In a preferred embodiment no part of the mechanism for forcing the liquid out of the bag to the dispensing location ever touches the liquid. Maintaining sanitary conditions is made very easy.  
         [0010]     Using the type of prior art pinch valve and flexible tube arrangement of U.S. Pat. No. 6,186,361, incorporated herein by reference, the dispensed liquid touches no permanent part of the dispenser on its way from the collapsible container to the tip of the tube from which it is dispensed.  
         [0011]     Delivery of liquid to a dispensing location in the manner of this invention as described above permits even non-carbonated or “still” consumable liquids to be pumped from a remote location to a dispensing location. In one exemplary and preferred embodiment the remote location of the compressible, flexible liquid container is a below-counter location while the dispensing location is an above-counter location. A relatively narrow stem projecting upward from the counter leads one or more of the flexible liquid delivery tubes to the dispensing location. Little counter space is used for dispensing the liquid. The under-counter location containing the flexible liquid filled bag and the inflatable bladder can be refrigerated. Also a compressor or air pump for supplying compressed air to the bladder can be housed below the counter. The under-counter location can be in a cabinet directly under the dispensing location.  
         [0012]     In the exemplary embodiment, the under-counter cabinet contains one or more enclosures or compartments. Each enclosure or compartment contains one or more of the flexible liquid filled bags and one or more bladders in contact with the bag or bags. Each enclosure that is equipped with one or more of the inflatable bladders has a structure that confines the bladder in contact with the flexible bag so that pressure from the bladder is exerted against the flexible liquid-containing bag. In an exemplary preferred embodiment described below the enclosure is a slidable drawer and the structure confining the bladder in contact with the bag is a stationary lid supporting the drawer for sliding movement. Preferably, as a safety feature, one or more safety shut off switches serve to relieve the pressure in the bladder or bladders in an enclosure when the enclosure is opened. The switch or switches serve as safety interlock devices, preventing pressure in the inflatable bladder or bladders expanding the bladder explosively when the drawer is slid out from under its lid, possibly injuring an attendant.  
         [0013]     In an embodiment where a variety of products are dispensed, the enclosures and the liquid containers that they accommodate can be of various sizes so as to take into account varying demand for the products. The enclosure can be modular, entirely removable and replaceable so as to permit a dispenser to be modified and tailored to the needs of a particular installation. In the case of the drawer and stationary lid, both drawer and lid can be attached and detached as a single module facilitating removal and replacement of one size enclosure with another.  
         [0014]     In one embodiment of the invention, the liquid delivery system delivers one or more of cream, non-dairy creamer, milk, half and half and/or other coffee and tea additives such as flavorings from the flexible bags at the below-counter location to the above-counter dispensing location. In a fast food restaurant, convenience store or elsewhere, valuable counter top space is conserved.  
         [0015]     In one particular embodiment, a below-counter cabinet containing the consumable liquid store is on wheels, casters or sliders or other means facilitating the movement of the cabinet, making the cabinet, its counter and the liquid dispenser easily moved from one location to another. This is an embodiment useful for hotels and resorts that set up refreshments at various locations in connection with conferences, meetings, parties, etc. held in various conference rooms.  
         [0016]     In any of the above embodiments of the invention, where refrigeration of the liquid to be dispensed is important, cooling by the refrigeration unit can extend upward from an under-counter location to a location at or very near the dispensing location. This is important in dispensing dairy product such as cream, milk or half and half for coffee or tea. Where, as described above, a stem containing a liquid delivery tube extends upward from a counter top, that stem&#39;s interior can be in communication with the refrigerated location of the liquid bag or bags below the counter in accordance with one aspect of this invention. Cooling of the stem interior by convection can be assisted by a fan moving refrigerated air into the liquid delivery path. Additionally for good conduction of heat away from the liquid dispensing location and away from the flexible tube or tubes leading the liquid to the dispensing location, a return air flow channel may extend into and along the inside of the stem.  
         [0017]     Preferably, too, in some embodiments, the pinch valve or valves that normally pinch the one or more flexible tubes closed are electrically operated from a manually activated switch or switches at the dispensing locations. Electrical solenoid-operated pinch valves suitable for use in this invention are commercially available items. Although, without departing from the invention, manually operated pinch valves can be used. These may be of the kind described in U.S. Pat. No. 6,186,361, incorporated herein by reference. In either case the valves, their manual actuators and the stem that communicates with the under counter refrigeration unit can be part of a dispensing head supported on the stem.  
         [0018]     An aspect of this inventive liquid dispenser addresses the problem of consistency in doses of coffee or tea additives. This is a dosing valve that meters out a consistent dose of the additive each and every time the dispenser is operated. The valve is a slide valve that, when the slide is spring biased to its “home” position defines a chamber in a close fitting housing in which the slide moves. The chamber, so-defined, is in communication with the tube supplying the additive from the collapsible bag that is the additive store. Movement of the slide to the dispensing position moves a liquid path formed in the slide between the chamber and a liquid emission opening through a wall of the housing. At the same time the slide closes the communication path between the chamber and the tube. An air passage between the outer surface of the slide and its housing allows the slide to return towards its home position under the influence of the biasing spring until the communication is again established between the chamber and the additive supply tube. As the additive again fills the chamber, air is displaced and escapes along the air passage.  
         [0019]     The above and further objects and advantages of the invention will be better understood in connection with the following detailed description of the invention taken in consideration with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1 . is a perspective view of an installed consumable liquid dispensing station according to this invention and shows a fountainhead installed on a countertop above a cabinet housing a store of consumable liquids;  
         [0021]      FIG. 2  is a further perspective view of a refrigeration unit outer shell for installation in a cabinet like that of  FIG. 1 ;  
         [0022]      FIG. 3  is a further perspective view of the refrigeration unit and shows a pair of pumps and an evaporator installed in place in the back of the refrigeration unit;  
         [0023]      FIG. 4  is a front elevation view of the refrigeration unit shell with door removed and shows a pair of fans located to move air over the evaporator of  FIG. 3 ;  
         [0024]      FIG. 5  is a perspective view upward from the front and bottom of a refrigerator subassembly housing the condenser of the refrigeration unit and shows a fan for moving air through an opening and over a condenser;  
         [0025]      FIG. 6  is a front elevation unit of the refrigeration unit with door removed and showing a number of consumable liquid storage drawers housed in the refrigeration unit;  
         [0026]      FIG. 6A  is a perspective view of a fitment that forms an outlet of a flexible bag of the consumable liquid;  
         [0027]      FIG. 6B  is a cross-sectional view of the fitment of  FIG. 6   a;    
         [0028]      FIG. 7  is a cross-sectional view of the refrigeration unit and drawers of  FIG. 6  along with the evaporator and condenser;  
         [0029]      FIG. 7A  is a cross-sectional view of one drawer in the refrigeration unit and illustrates an inflatable bladder, flexible liquid bag and the fitment of  FIGS. 6A  and B;  
         [0030]     FIGS.  8 A-D are cross-sectional views showing a drawer having an inflatable bladder in pressure exerting relation to a flexible consumable liquid bag that is full, partially emptied, and entirely emptied;  
         [0031]      FIG. 9  is a right side elevation view of the fountain head of  FIG. 1 ;  
         [0032]      FIG. 10  is a top plan view of the fountainhead of  FIG. 9 ;  
         [0033]      FIG. 11  is a perspective view of a front section of a fountainhead in accordance with the invention and shows air movement conduits therein;  
         [0034]      FIG. 12  is a perspective view of a top part of the fountainhead of  FIG. 1 ;  
         [0035]      FIG. 13  is a perspective view of a rear part of a stem portion of the fountainhead of  FIG. 1 ;  
         [0036]      FIG. 14  is a front elevation view of a fountainhead with electrically operated dispensing valves;  
         [0037]      FIG. 15  is a diagrammatic illustration of a dosing dispensing valve;  
         [0038]      FIG. 16  is a schematic illustration of the electrical and compressed air circuits of the dispensing system of the invention; and  
         [0039]      FIG. 17  is a partial sectional side view showing a pinch valve and dispending tube of a prior, incorporated-by-reference patent and of the kind that can be employed in the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0040]     Turning now to  FIG. 1  there is shown a consumable liquid dispensing station  20  in accordance with the invention. The station  20  includes a cabinet  22  having a door  23  and an upper surface  24  formed by a counter  26 . A fountainhead  28  is secured to the upper surface  24 . Wheels, casters or sliders  29  at the bottom of the cabinet  22  afford easy movement of the station  20 .  
         [0041]     The fountainhead  28  has a base  31  resting on the counter surface  24 . A drip tray  33  is shown supporting a cup  34 . A hollow stem  35  extends upwardly from the base  31  supporting a dispensing head  36 . A series of five manually activated push buttons  38  are the activators of manually operable pinch valves that normally pinch closed five flexible consumable liquid supply tubes as described in greater detail below. A user pushes one or more of the push buttons  38  to choose the consumable liquid of choice. The available products are identified at the five displays  39  aligned with the push buttons  38 . Additional information can be displayed at a display area  41 . This can be a passive or active electronic display. At  42  can be found a temperature readout of temperature in the fountainhead as determined by a suitably chosen, commercially available temperature sensor located there. At  43  low product and out of product indications are provided by LEDs. Supported on the fountainhead  28  in a fashion described in greater detail below is a placard  45  that may contain advertising or additional product information. The fountainhead  28  is particularly well suited for supplying coffee or tea additives such as cream, half and half, non-dairy creamer, flavorings, etc., but can be as well, a dispenser of fruit juices, water or other beverages. In the embodiment of  FIG. 1  the station  20  is readily moved to a location such as a hotel or resort conference room to serve at conference breaks, for example. Unlike prior dairy and non-dairy coffee additive dispensers, the fountainhead  28  leaves open a substantial amount of countertop that can be put to further good use. In the conference setting, this may support the familiar carafes of coffee and tea.  
         [0042]     The cabinet  22  of  FIG. 1  houses a refrigeration unit  50 . That unit&#39;s shell appears in  FIG. 2 . The shell is an insulated box-like structure with insulated walls  51  and  52 , an insulated floor  53  and an insulated top wall  55 . It is sized to fit closely within the cabinet  22  of  FIG. 1 . An insulated door  56  swings open as shown in  FIG. 2  to allow access to the interior of the refrigeration unit. A magnetic latch (not shown) like that used on home refrigerators ordinarily holds the door  56  closed. At  58  a generally square opening through the top  55  of the shell communicates between the interior and exterior of the unit. Into this opening a lower stem of the fountainhead  28  will extend. Such a stem  47  can be seen in  FIGS. 9 and 14 , for example. To accommodate the stem an opening similar in size to the opening  58  is formed in the counter  26  of  FIG. 1  in alignment with the opening  58 .  
         [0043]     Turning to  FIG. 3  the refrigeration unit  50  is again seen, but in perspective view from the rear  59  and side  52  of the unit. In a subassembly  62  a pair of pumps  64  and  65  are housed. One of these pumps,  64 , supplies compressed air and the other,  65 , pumps refrigerant. The refrigeration unit&#39;s evaporator  57  is located in a recess  69  in the back  59  of the unit  50 . The recess  69  ultimately is closed by a panel  71 , a fragment of which is shown in  FIG. 3 . Because the opening  58  in the top of the refrigeration unit  50  is generally square in cross section, as is the stem  47  that extends into it, the fountainhead  28  can face in any of four directions, as the particular installation site may dictate.  
         [0044]     In  FIG. 4  the refrigeration unit  50  is shown with its door removed. Looking into the interior, one sees a pair of fans  74  and  75 . These draw air over the evaporator  67 . They are installed inward of the evaporator in a partition  76 .  
         [0045]     In  FIG. 5  the subassembly  62  appears in perspective looking up from its bottom  78 . A fan  79  draws air into the subassembly housing through an opening  81  in the bottom  78  and expels that air at the opening  82  where the fan  79  is secured. A filter  84  is inserted through an opening  85  in the front face  86  of the subassembly  62  to filter air introduced into the subassembly and prevent dust build-up on a condenser,  88  in  FIG. 7 , that is housed in the subassembly  62 . Also in  FIG. 7 , on top of the condenser  88 , where evaporation is aided by greater warmth, a catch basin  89  receives condensation via a tube  90  from a drip tray  83  below the evaporator  67 . A further temperature display  87  is on the face of the subassembly  62 . Controls for the refrigeration unit  50  may be located on the face of the subassembly  62 . The temperature is that within the refrigeration until  50  as measured as known in the art by a suitably chosen commercially available temperature sensor.  
         [0046]     In  FIG. 6  the interior of the refrigeration unit  50  is illustrated with five drawers  91 - 95  in place. Each drawer is equipped with a lid  101 - 105 . Each lid is affixed to the underside of a shelf  107 ,  108  or  109 . Brackets  111  or other supporting means secure the shelves in place. Each drawer  91 - 95  has a pair of U-shaped channels  112  formed along the sides thereon. Each lid  101 - 105  has a pair of laterally outwardly projecting flanges  113  received in each of the channels  112  and supporting the associated drawer. Thus supported, the drawers  91 - 95  are able to slide forward toward the open front of the refrigeration unit  50 .  
         [0047]     As is evident in  FIG. 6 , the drawer  91  is larger than the remaining drawers  92 - 95 . This drawer  91 , then, is used to contain a larger collapsible bag and to supply the product most often chosen by users of the dispenser  20 . Of course, other configurations with varying drawer sizes and fewer or more drawers for the dispensing of fewer or more products may be readily accomplished.  
         [0048]     Five flexible liquid supply tubes  115 - 119  extend from the drawers  91 - 95  upward to the fountainhead through the opening  58 . At their lower ends, the tubes  115 - 119  connect with hollow outlet connections  121  of a series of fitments  122 . These fitments  122 , better seen in  FIGS. 6A and 6B , fit onto five outlet connections  124 , each secured to a consumable liquid supply bag  125  ( FIG. 7A ) in each of the drawers  91 - 95 . As shown in  FIGS. 6A and 6B , each fitment  122  has a series of spaced prongs  127 . The connection  124 , which opens into each interior consumable liquid bag extends downward and into the interior  128  of the fitment  122  as indicated in dashed lines in  FIG. 6B . The two pieces snap securely together. The fitment defines the liquid flow path from the interior of the collapsible container that is the bag  125  to the attached liquid supply tube.  
         [0049]     As shown at  131 - 136  in the cross-sectional view of  FIG. 7 , for liquid flow, bottoms of the drawers  91 - 95  slope towards the opening through the connection  124  and fitment  122 . In addition to each liquid containing flexible bag  125 , each drawer contains an expansible bladder  143  like that shown in  FIG. 7A . This bladder is supplied air under pressure from the pump  64  via compressed air lines  146 - 151  through couplings  153 . The expansible bladders  143  are confined in force exerting relation to the flexible, collapsible liquid containing bags  125 . As shown in the broken away portion of bag  125  in  FIG. 7A , the upstanding prongs  127  of the fitment  122  project into the bag somewhat higher than the bag bottom at the opening from the bag. These prongs prevent collapse of the bag under the influence of the expansible bladder  143  into liquid flow-blocking relation to the opening as the liquid is exhausted. The upstanding prongs define between them spaces through which the liquid can flow until the collapsed bag  125  is substantially completely empty.  
         [0050]     Shown in  FIG. 8C  a pair of Hall switches  165  and  166  are mounted by a bracket  168  to detect the proximity of a magnet  169 . The magnet  169  is secured, by for example gluing, to the bottom of the bladder  143 . This arrangement serves as a sensor to detect and indicate a low liquid level and an out-of-liquid condition.  
         [0051]      FIGS. 8A and 8B  illustrate the inflatable bladder  143  collapsed when the bag  125  is completely full.  FIG. 8C  shows the bag  125  partially empty and the bladder  143  partially inflated. Shown in full lines in  FIG. 8C , the bag  156  is not yet at the low liquid level, but shown in broken lines at  143 ′ is the location of the bottom surface of the bladder  143  when it has brought the magnet  169  into proximity with the low liquid level Hall switch  165 . This causes a change of state in the Hall switch used to indicate low liquid level. Finally, in  FIG. 8D , the “out-of-liquid” condition is sensed by the hall switch  166  when the bag  125  is substantially empty and the bladder  143  is completely inflated. By a simple electrical circuit known in the art, the switches  165  and  166  are electrically connected to and turn on “low-level” and “out-of-liquid” LED indicators (not shown). These are located on the fountainhead where they will be visible to an attendant.  
         [0052]     In  FIGS. 9-13 , the fountainhead  28  is shown in further detail. In the right side view of  FIG. 9  it can be seen that the fountainhead  28  is constructed of three molded pieces. These are the front  171 , the top  172  and the back  173 . In the top view of  FIG. 10 a  slot  175  in the top  172  receives a downward extending tab  176  of the placard  45 , to support the placard.  
         [0053]     The three molded elements  171 ,  172  and  173  that make up the fountainhead are shown in  FIGS. 11, 12  and  13 , respectively. These are molded of an insulating material, such as a plastic foam sandwiched between inner and outer plastic “skin” layers. There the internal construction of the fountainhead can be seen. The front  171  and back  173  come together to form two channels  176  and  177  separated by a molded baffle  178 ,  178 ′. The channels  176 ,  177  lead upward from the stem  147  and are in communication with the refrigeration unit below. At their interface, the front  171  carries seals  179 ,  181  and  183  in long slots extending along the sides of the channels  176  and  177 . These seals are received in conforming slots  185 ,  187  and  189  formed in the back  173  along the channels  176  and  177  where the back and front interface. Carried in the bottom of the channel  176  a fan  190  delivers refrigerated air into the channel  176 . The refrigerated air travels up the channel  176 , circulates about the interior of the fountainhead at its top and is withdrawn back into the refrigeration unit along the channel  177 . It is through the channel  177  that the flexible tubes  115 - 119  pass on their way to the dispensing location at the underside of the front  171  of the fountainhead  28 . The top  172  of the head  28  as seen in  FIG. 12  has a short section  192  of the baffle that separates the channels  176  and  177 . A short slot  193  receives an upper end of the seal  181  of  FIG. 11 .  
         [0054]     Held in place by a bracket  195 , as seen in  FIG. 11 , five pinch valves  197  receive the ends of the tubes  115 - 119 . From  FIGS. 11, 12  and  13 , it will be seen that the liquid supply tubes  115 - 119  are cooled along their length as they proceed through the refrigeration unit and into the fountainhead. This cooling is particularly important for dairy product that must be maintained below a government prescribed temperature.  
         [0055]     In an alternate embodiment of the invention illustrated in  FIG. 14 , solenoid driven pinch valves, known in the art and commercially available, are used. The fountainhead  200  of this embodiment has electrically operative touch pads  201  or other electrical switch activation means to activate a solenoid and cause the release of a pinch valve normally biased closed as is known in the art. In other respects, the head  200  is similar to the head  28  previously described. Cooling air flow is the same as described with respect to the head of  FIGS. 11, 12  and  13 . A temperature readout like that of  FIG. 1  indicates temperature within the dispensing head and low liquid and out of liquid LEDs can be provided.  
         [0056]      FIG. 15  illustrates an alternative to the previously described pinch valves controlling the flow of liquid from the fountainhead  28 . The valve  210  of  FIG. 17  connects to the output end of a flexible liquid supply tube  115  for example. A housing  211  receives a slide  212 . The slide is urged by spring  214  to the rest or home position at which it is shown in  FIG. 17 . The slide fits in liquid-tight relation to the housing. However at a location along its perimeter an air escape passage  215  is provided such as a channel or flat or other configuration forming a space between the valve slide and its housing communicating between the interior of the housing  211  and atmosphere. In the home position of the slide as shown the slide  212  and the housing  211  form a chamber  217 . The chamber communicates with the tube  115  through an opening in the chamber at  218 . Liquid product from the refrigeration unit enters the chamber  217 , filling it. Air displaced by the liquid as it fills the chamber  217  escapes along the passage  215  allowing the chamber  217  to be filled with liquid. To measure out a consistent portion of the liquid, the slide  212  is pushed to the left in  FIG. 17 , either manually or by activation of a solenoid or the like. An opening  219  in the slide moves into alignment with an output opening or spout  220  opening into the housing  211 . At that point liquid in the chamber  217  is forced out of the chamber  217  into a hollow interior  221  or other path or passage through the slide  212  and out of the valve through the opening  219  and the spout  220 . The exterior of the slide  212  closes off the opening  218  as it is pushed to the left and a measured dose of the liquid is dispensed. Upon release of the slide  212  it returns to its home position under the urging of the spring  214 . Initially, air moves into the chamber  217  allowing the slide to move towards its home position and until the opening  218  is again opened into the chamber  217 . At that time, chamber  217  again fills as air is expelled.  
         [0057]     Returning to  FIG. 6 a  pair of safety shut off safety interlock switches  225  and  226  are supported on the shell of the refrigeration unit  50  to be activated by the door of the unit when the door is closed. Any suitable commercially available switch can serve. Limit switches and proximity sensors are just two alternatives that may be used. How those switches operate is better described in connection with the circuit of  FIG. 19 . There the switches  225  and  226  are seen to be connected in series and are hence redundant for a greater measure of safety. Opening one or both switches, by opening the door of the unit  50 , interrupts a circuit from a DC power supply  228  to four electrically operated valves  230 ,  231 ,  232  and  233 . Ordinarily, with the door of the refrigeration unit  50  closed, air pump  64  is operative to apply air pressure elevated to something less than 8 PSI to an output line  235  and through a check valve  236 . Air is supplied to the vacuum side of the pump  64  via a filter  253 , valve  233  and a line  254 . An air pressure meter  237  monitors the pressure in the line  235 . From the line  235  the increased air pressure branches to lines  238  and  239 . Air pressure line  238  serves as an input to the first valve  230 , a valve that maintains the connection between a pair of air lines  241  and  242  normally open. In its normally open state the valve  230  applies the air pressure of the line  238  to the line  242 . A further pressure meter  244  monitors that pressure. The second valve  231  maintains the connection between the line  242  and a further line  245  normally closed. The line  245  applies the increased air pressure output of the pump  64  to a manifold  246  which distributes the air at the raised pressure to the bladders  143  via lines  248  and  249  and the lines  147 - 151  previously discussed. A pressure switch  256  monitors the pressure in the line  242  via a line  257  to interrupt the circuit from mains power at  259  to the pump  64  when that pressure falls. Initially, at startup, pressure is built in the line  242  by the pump by means of a timed breaker  261  that, upon application of the output of the DC power supply shorts out the pressure switch  256  for a period sufficient to pressurize the system.  
         [0058]     When one or both safety switches  225  and  226  open, the valve  230  connects the air lines  241  and  242  thus connecting line  242  to the intake of the pump  64  and dropping the pressure in the line  242 . The valve  231  at the same time vents the line  245  to atmosphere through the valve outlet  265  marked “EXH.” Through the manifold  246  the bladders  143  are thus vented to atmosphere, deflating the bladders and making it safe to open the drawers containing the bladders and the flexible bags containing the liquid product. The output of the pump  64 , also, is vented to atmosphere by the closing of the normally closed valve  232 . The air intake and filter  253  are disconnected from the vacuum side of the pump  64  by the opening of the normally open valve  233 . The loss of air pressure in the line  242  is communicated to the pressure switch  256  which interrupts the mains power to the pump  64 .  
         [0059]     As shown in  FIG. 17 , a manually operable pinch valve  350  of the kind shown in  FIG. 9  of the incorporate-by-reference U.S. Pat. No. 6,186,381, can be employed to control the flow of dispensed liquid from the collapsible containers  125 , e.g., of  FIG. 7A . A spring  354  normal biases a slide  353  to pinch closed at location  372  the tube,  115  for example, near its dispensing tip  356 . Manual depression of an external slide acts against the bias of the spring  354  to unpinch the tube and allow the dispensed liquid to flow.  
         [0060]     With the incorporated-by-reference valve of the above-cited U.S. Pat. No. 6,186,361 as shown in  FIG. 17 , liquid is dispensed from the tip of the tube  115  extending below the pinch valve. This means that in its movement from the collapsible container  125  (of  FIG. 7A ), through the tube  115 , to the tube tip  356  as shown in  FIG. 17 , the fluid touches no permanent part of the dispenser, i.e. just the disposable container  125 , tube  115  and attaching means. This significantly reduces the need for cleaning internal dispenser parts when liquids subject to spoilage are dispensed. Likewise the use of the inflatable bladder motivated delivery of liquid eliminates passage of the liquid through any pump that would need regularly to be pulled apart and cleaned.  
         [0061]     Although preferred embodiments of the invention have been described in detail, it will be readily appreciated by those skilled in the art that further modifications, alterations and additions to the invention embodiments disclosed may be made without departure from the spirit and scope of the invention as set forth in the appended claims.

Technology Category: 7