Abstract:
Apparatus for dispensing a post-mix beverage is characterized by a beverage concentrate metering system comprising a reservoir of beverage concentrate, a disposable pump unit containing a pair of piston pumps and inlet and outlet valves from each piston pump. The inlet valves are coupled to the reservoir of beverage concentrate and the outlet valves are coupled to a mixer. A control valve introduces diluent to the concentrate intermediate the outlet valves and mixer and a reusable pump drive operates the piston pumps. The control valve and pump drive are operated by a control system in a manner such that a predetermined ratio of diluent to concentrate is delivered to the mixer. Downstream from the mixture the admixture of diluent and concentrate is dispensed as a beverage into a cup.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to beverage dispensers, and more specifically to dispensers for dispensing a diluted beverage concentrate.  
       BACKGROUND OF THE INVENTION  
       [0002]     Beverage dispensers for juice, particularly for orange juice, are required to pump a high viscosity juice concentrate and accurately control the ratio of juice concentrate to diluent to produce a beverage of uniform standard. Such dispensers commonly comprise a diluent inlet line from a pressurised diluent source, a juice concentrate reservoir and means for delivering concentrate from the reservoir to the dispenser, which delivering means customarily comprises one of means for pressurising the concentrate reservoir and controlling the flow of concentrate through a valve, means for pumping concentrate from the reservoir and controlling the flow through a valve, or means for volumetrically pumping concentrate from the reservoir. It is known that there are advantages to having a juice concentrate delivery system in which those parts of the system that contact the concentrate are disposable in order to maintain sanitation and reducing the risk of contamination through substandard cleaning of the system.  
         [0003]     To improve sanitation in the delivery of juice concentrate from a concentrate reservoir to a juice dispenser the art contemplates use of a rotary peristaltic pump to deliver the concentrate, a deformable tube of which pump forms an integral part of a disposable concentrate reservoir, and use of a positive displacement pump that includes a disposable piston-type pump portion supplied with the concentrate reservoir and a non-disposable drive for reciprocating the pump to draw fluid into and expel it from the disposable pump, as shown in U.S. Pat. Nos. 5,114,047 and 5,154,319.  
         [0004]     Peristaltic pumps provide a reasonable solution for sanitation problems, but often experience problems pumping higher viscosity fluids such as juice concentrate, and as the viscosity of juice concentrate can be highly dependant on its temperature, peristaltic systems often do not dispense a correct ratio of juice concentrate to diluent at lower temperatures. In addition, the tube part of the pump often deforms to a permanent set over time, such that the volumetric output towards the end of its life is less than that at the beginning of its life, again affecting the ratio of the mix of concentrate to diluent.  
         [0005]     Positive displacement pumps, such as that in U.S. Pat. No. 5,114,047, produce a more constant ratio of the mix of juice concentrate to diluent, but because they have a fill cycle and a dispense cycle, the beverage will have a stratified appearance as it exits the dispenser as a result of the concentrate being intermittently dispensed into the diluent stream.  
       OBJECT OF THE INVENTION  
       [0006]     A primary object of the invention is to provide a beverage dispenser incorporating a relatively inexpensive piston pump having a disposable pumping portion that is incorporated into a concentrate cartridge and that is capable of pumping high viscosity concentrate at a substantially continuous flow rate.  
       SUMMARY OF THE INVENTION  
       [0007]     In accordance with the present invention, apparatus for dispensing a post-mix beverage comprises a reservoir of beverage concentrate; a disposable pump unit including a pair of piston pumps having inlet means fluid coupled to beverage concentrate in the reservoir and outlet means; and pump drive means for being coupled to the disposable pump unit for operating the pump unit to pump concentrate from the inlet means to the outlet means. Also included is a mixer fluid coupled to the pump unit outlet means; a control valve having an inlet for being fluid coupled to a supply of diluent for the beverage concentrate and an outlet for being fluid coupled to introduce diluent to beverage concentrate intermediate the disposable pump outlet means and the mixer; and control system means. The control system means operates the pump drive means and the control valve to provide a predetermined ratio of diluent to concentrate as delivered to the mixer.  
         [0008]     The invention also contemplates a method of dispensing a post-mix beverage, which method comprises the steps of providing a reservoir of beverage concentrate; fluid coupling an inlet to a pair of piston pumps of a disposable pump unit to beverage concentrate in the reservoir; and fluid coupling an outlet from the pair of piston pumps to a mixer. Also included are the steps of connecting a pump drive to the disposable pump unit to operate the piston pumps; controlling the pump drive to reciprocate pistons of the pair of piston pumps of the disposable pump unit to pump beverage concentrate from the inlet to the pair of piston pumps to the outlet from the pair of piston pumps; delivering beverage concentrate from the outlet from the piston pumps to a mixer; and fluid coupling diluent for the beverage concentrate from a supply of diluent through a control valve to the beverage concentrate being delivered to the mixer to introduce diluent to the concentrate. Further included is the step of controlling operation of the pump drive and the control valve so that a predetermined ratio of diluent to beverage concentrate is delivered to the mixer.  
         [0009]     The foregoing and other objects, advantages and features of the invention will become apparent from a consideration of the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:  
         [0011]      FIG. 1  is a schematic diagram of a dispenser in accordance with the invention;  
         [0012]      FIG. 2  is a perspective view of a twin barrel syringe pump for use in the invention; and  
         [0013]      FIG. 3  is an exploded diagram of a concentrate reservoir, pump and mixing element for use in a dispenser of the invention.  
     
    
     DETAILED DESCRIPTION  
       [0014]     Referring to  FIG. 1 , a schematic diagram of a beverage dispenser  1  connected to a diluent supply  2 , which may be a supply of mains water. When the diluent enters the dispenser it is cooled in a cooling unit  3  to the required temperature for a beverage, commonly in the region of about 35° F. to 43° F. The cooling unit  3  may be a water bath heat exchanger or other type of cooling technology known in the art, such as a cold plate. An electronic controller  4  receives signals from a diluent flow measurement device (not shown) that may be part of a control valve  5  through which passes cooled diluent from the cooling unit  3 . Electronic controller  4  operates both the control valve  5  and a pump drive  6  in a manner to bring together cooled diluent and juice concentrate in a predetermined ratio for being mixed together and dispensed as a beverage. Situated within or attached to dispenser  1  is a disposable concentrate unit  7 . The concentrate unit  7  comprises a concentrate reservoir  8 , a twin barrel piston pump cartridge  9  driven by the pump drive  6  and connected to and for receiving juice concentrate from the concentrate reservoir  8 , a diluent conduit  10  fluid coupled to an outlet from the control valve  5  for delivering cooled diluent to the concentrate unit  7  for introduction to juice concentrate delivered from the piston pump cartridge  9 , and a static mixer  11  for mixing the juice concentrate and diluent to form a homogeneous mixture.  
         [0015]      FIG. 2  shows an output from the non-disposable pump drive  6  mechanically coupled to the twin barrel piston pump cartridge  9 . A contemplated embodiment of the twin barrel piston pump  9  comprises two syringe type pump cylinders or barrels  12  and  13  that have associated inlets  14  and  15  fluid coupled to juice concentrate in the concentrate reservoir  8 . The pump inlets  14  and  15  are provided with respective inlet check valves  16  and  17  that allow flow of concentrate from the concentrate reservoir  8  through the inlets into the pump barrels  12  and  13 , but prevent backflow of concentrate out of the barrels through the inlets. The barrels  12  and  13  also have associated outlets  18  and  19  fluid coupled to the static mixer  11 . The outlets  18  and  19  are provided with respective outlet check valves  20  and  21  that allow flow of concentrate from the barrels through the outlets to the static mixer  11 , but prevent a reverse flow of concentrate back through the outlets.  
         [0016]     In operation of the concentrate pumping mechanism, a pair of rotary cams  22  and  23  is coupled to an output from the pump drive  6  for being rotated by the pump drive. The cams  22  and  23  are also coupled via interface means comprising associated piston or cam rods  24  and  25  to respective ones of a pair of plungers or pistons  26  and  27  disposed for reciprocation in respective cylinders  12  and  13 . Operation of the pump drive  6  therefore rotates the cams  22  and  23  to reciprocate the pistons  26  and  27  in both directions in the piston pump barrels  12  and  13  to thereby alternatively draw concentrate into the barrels through the check valves  16  and  17  and to eject fluid out of the barrels through the check valves  20  and  21 . The arrangement advantageously is such that the directions of reciprocation of the pistons  26  and  27  through the cylinders  12  and  13  are 180° out of phase, so that while the plunger  26  is being drawn back through the barrel  12  to draw fluid into the barrel through the inlet  14  and the check valve  16 , the plunger  27  is being driven forward through the barrel  13  to expel fluid from the barrel through outlet  19  and check valve  21 . The cams  22  and  23  may be rotated together at a constant speed but, preferably, the rate of rotation of each cam is independently controlled and the speed of rotation is modulated, so that the plungers  26  and  27  are withdrawn through the barrels  12  and  13  at a faster rate than they are driven forward through the barrels, thereby to enable whichever barrel  12  or  13  is not then dispensing fluid to be fully filled with fluid and ready to dispense before the barrel that is then dispensing fluid is at the end of its dispensing stroke. The result is that the twin barrel piston pump  9  delivers to the mixer  11  a substantially constant and uninterrupted output flow of concentrate during a beverage dispense cycle.  
         [0017]      FIG. 3  shows a disposable liquid juice concentrate reservoir  28  that is connectable to a disposable twin barrel piston pump element or cartridge  29 . The pump element  29  includes a twin barrel piston pump  30  of a type heretofore described, for pumping the juice concentrate received from the reservoir  28 . A water inlet  31  through which a moderated flow of water is passed from the control valve  5 , provides for introduction of diluent to concentrate discharged from the pump  30 . The control valve  5  and the pump drive  6  are operated by the control electronics  4  in such manner as to provide, upstream of a mixer  32 , the bringing together of a predetermined constant ratio of diluent to juice concentrate, depending upon the particular beverage to be served by the dispenser  1 . The concentrate and water diluent are then flowed together through a static mixer  32  to provide a substantially homogeneous mixture of diluted concentrate which is dispensed into a receptacle in a conventional know manner. In the arrangement shown in this  FIG. 3  the disposable twin barrel piston pump  30  has plunger extensions  33  removably connectable to a pump driver, such as the pump drive  6 . The reservoir  28  has an outlet  34  to which one or more inlets to the disposable pump element  29  are connected for receiving concentrate. The reservoir outlet  34  is provided with a protective cap or film (not shown) to cover and seal it during storage and transport.  
         [0018]     It is appreciated that because the drive system reciprocates the pistons  26  and  27  alternately through their pumping strokes in the barrels  26  and  27  of the disposable twin barrel piston pump cartridge  9 , the pump provides a substantially constant and uninterrupted output flow of juice concentrate during a beverage dispense cycle. Also, because the juice concentrate flows primarily through the disposable concentrate unit  7 , which includes the disposable concentrate reservoir  8 , twin piston pump cartridge  9  and static mixer  11 , the juice concentrate comes into contact primarily with disposable parts, so that there are a minimum of non-disposable dispenser parts to be cleaned of juice concentrate, which provides for improved sanitation. When the reservoir of juice concentrate  8  is exhausted, the concentrate unit  7  is simply removed and replaced with a fresh concentrate unit having a full concentrate reservoir  8 , so there is no need to be concerned with cleaning the previously used concentrate reservoir  8 , twin barrel piston pump cartridge  9  and mixer  11 .  
         [0019]     Advantageously, because the pump drive  6  is controllable to operate independently on the two pistons  26  and  27  of the disposable pump element  9  to enable the pump fill cycle to be performed in a shorter time that the pump discharge cycle, provision can be made for a desired amount of overlap in the pumping actions of the two pump barrels, so that there is substantially no perceptible change in concentrate output from the pump as the output flow changes from one barrel to the other. The rotary motion of the cams  22  and  23  as driven by the pump drive  6  is translated into linear motion of the pistons  26  and  27 , such that control of the motion of the pistons can be dictated by control of the relative individual speeds at which the cams are rotated. Alternatively, an arrangement is contemplated where outer ends of the piston rods  24  and  25  would ride on outer peripheral cam surfaces of the cams  22  and  23 , in which case the cams could be rotated at the same speed with the speed of fill and dispense of the barrels  12  and  13  of the pump element  9  then being controlled by the profile of the cam surfaces.  
         [0020]     It is understood that the dispenser  1  has a user interface and can be programmed to operate the control valve  5  and the pump drive  6  to either dispense beverages of selected sizes or to accommodate a continuous pour mode in which the dispenser continuously dispenses a beverage until signalled to stop. Preferably, an input signal is provided to the control electronics  4  when a new concentrate unit  7  is installed with a full concentrate reservoir  8 , either by means of a user manually inputting a signal, for instance by pressing a reset button, or automatically by identification means on the concentrate unit, for instance an RFID tag on the concentrate reservoir and an associated reader in the dispenser  1 . The input signal would be used to initiate a drinks countdown, such that when there is only a specific amount of concentrate remaining, as determined by the size and number of drinks served, an indication is given to the operator that the concentrate will soon need replacing, with a second signal being sent to the operator when the concentrate reservoir is empty. These signals may take the form of warning lights of different colours or they could comprise a countdown of remaining drinks to be dispensed. In addition, control of the concentrate flow rate can initially be set in accordance with the parameters of the particular concentrate used. Such parameters may be stored in a memory of the control electronics  4  of the dispenser  1  or, alternatively, may be automatically input to the dispenser for each concentrate reservoir as it is installed, for example by means of data stored in a RFID tag or input by an operator manually or via a handheld device.  
         [0021]     Further, while the invention has been described as having the concentrate reservoir  8  and disposable twin barrel piston pump cartridge be part of a single unitary component, i.e., the concentrate unit  7 , it is contemplated that the concentrate reservoir and disposable pump cartridge be supplied as two separate parts which are connected together either immediately prior to or during installation into the dispenser. Preferably, once the disposable pump cartridge  9  and juice concentrate reservoir  8  have been connected they cannot be disconnected, thus preventing reuse of the pump cartridge. However, should the pump cartridge and reservoir be capable of disconnection for reuse of the pump cartridge, then a limitation is placed on the number of times the pump cartridge can be reused.  
         [0022]     While embodiments of the invention have been described in detail, various modifications and other embodiments thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.