Abstract:
The present invention is dispensing valve that provides for automatic and accurate fluid ratioing of two fluids. A valve body is designed to be easily assembled and disassembled by hand without the need for hand tools, and includes a first liquid flow body and a second liquid flow body releasably securable to a common nozzle body portion. The first and second liquid flow bodies each include flow sensors and the first liquid flow rate is adjusted to the sensed second liquid flow rate. The flow rate of the first liquid is regulated by a linear actuator operating a shaft through an orifice located in a flow channel of the first liquid flow body. The position of an end of the shaft relative to the orifice regulates the cross-sectional size of the flow channel through the orifice and therefor regulates the flow rate of the first liquid as a function of that cross-sectional size. The flow of the second liquid is regulated by an on/off device. An electronic control receives input from the flow sensors and regulates the flow of the first liquid based thereon. A method of control is seen wherein an allowable positive and negative instant dispense ratio is predetermined along with a smaller allowable positive and negative total dispensed liquid ratio, both ratios with respect to a predetermined exact desired ratio. The control moves to obtain a ratio that is first within the wider instant ratio and then to obtain a ratio within the narrower total dispensed ratio. This control approach provides for a steady and easily controlled movement of the ratio to the desired target ratio with minimal operation of the linear actuator.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to post-mix beverage dispensing valves and in particular to such valves having active ratio control apparatus.  
         BACKGROUND  
         [0002]    Post-mix beverage dispensing valves are well known in the art and are typically used to mix together two beverage constituents at a desired ratio to produce and dispense a finished drink. Such constituents generally consist of a concentrated syrup flavoring and a diluent comprising carbonated or uncarbontaed water. Various control strategies have been employed to maintain the desired syrup to water ratio. “Piston” type flow regulators are a well known purely mechanical system that employ spring tensioning of pistons that constantly adjust the size of orifice flow openings to maintain the desired ratio between the fluids. However, a failing with such systems is that they require both fluids to be held within relatively narrow flow rate windows in order to work effectively. As is well understood, differences in ambient temperature, syrup viscosity, water pressure and the like can all conspire to affect one or both of the flow rates to a degree that the drink is ratioed improperly becoming either too dilute or too concentrated. As a result thereof, a drink that is too sweet can waste syrup costing the retailer money, and whether too sweet or not sufficiently so, presents the drink in less than favorable conditions, also reflecting negatively on the retailer as well as the drink brand owner. Volumetric piston dispense systems, as differentiated from the above piston based flow regulators, attempt to measure the volumes of each liquid using the known volume of a piston and the stroke thereof. Thus, two pistons, one for the syrup and one for the water are driven simultaneously by the same shaft or drive mechanism and are sized to reflect their desired volume ratio difference. Thus, operation of both pistons serves to move the desired volume ratio of each of the fluids from separate sources thereof to the dispense point or nozzle of the valve. However, these systems have met with difficulty in that there inherently exists a mechanical complexity relative to providing for inlet and outlet lines to each piston and providing for the correct timing of the opening and closing of such lines. Such complexity increases cost, imposes manufacturing difficulties and reduces operating reliability. Also, there exist size constraints that require the pistons to be relatively small resulting in high operating speeds that lead to corresponding seal and other mechanical wear issues, as well as undesired pumping phenomena where less than a full volume is moved with each pump stroke. Naturally, such wear and pumping inaccuracy problems can negatively impact the ratio accuracy.  
           [0003]    Electronic post-mix valves are also known that utilize sensors for determining the flow rate of either the water, the syrup or both, and then, through the use of a micro-controller, adjust “on the fly” the flow rates of either or both of the water and syrup. In addition, hybrid systems are known that utilize both a volumetric piston approach for the syrup and a flow sensing of the water flow. However, such post-mix valves continue to be plagued with cost and reliability problems. The sensors, for example, can be both costly and unreliable. Thus, maintenance of such post-mix valves by trained service technicians remains a large part of the life cost thereof. In general, it appears that the ratioing technology employed in such electronic valves, while useful in large scale fluid ratioing applications, does not translate well into the relatively small size requirements required of such valves.  
           [0004]    Accordingly, there is a great need for a post-mix valve that can accurately maintain the proper drink ratio consistently over time regardless of changes in temperature, flow rate and so forth and that is low in cost both as to the purchase price and the maintenance thereof.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention comprises a post-mix beverage dispensing valve that provides for automatic and accurate fluid beverage constituent ratioing, and that is reliable and relatively inexpensive to manufacture and operate. A valve body is designed to be easily assembled and disassembled by hand without the need for hand tools, and includes a water flow body and a syrup flow body releasably securable to a common nozzle body portion. The water and syrup flow bodies each include a horizontally extending flow channel fluidly intersecting with a vertically extending flow channel. The horizontally extending channels of the water and syrup flow bodies each include open ends for connection to sources of water and syrup respectively, and include fluid flow sensors. When secured together, the water, syrup and nozzle bodies are securable as an intact unit to an L-shaped support plate having a horizontally extending base portion and a vertically extending connection facilitating end. A quick disconnect block provides for releasable fluid tight sealing with the open ends of the horizontal water and syrup channels and, in turn, releasable fluid tight sealing with fittings extending from a beverage dispense machine. The bottom end of the support plate includes a hole centered below a bottom end of the nozzle body through which a nozzle is secured to the nozzle body. Water and syrup channels in the nozzle body deliver the water and syrup thereto for mixture within the nozzle for dispensing there from into a suitable receptacle positioned there below. The syrup channel in the nozzle body includes an adjustment setting mechanism that serves as a gross setting for the syrup flow rate within a certain desired range.  
           [0006]    The water body horizontal channel flow sensor is of the turbine type and disposed in the channel and includes hall-effect electronics for determining the rotational velocity of the turbine. That velocity information is provided to a micro-controller for determining the flow rate of the water. The syrup body horizontal channel sensor comprises a pair of strain gauge type pressure sensors mounted to and in an exterior wall portion of that channel and extending there through so that the operative parts thereof are presented to the syrup stream. The sensors are also connected to the micro-controller and are positioned on either side of a restricted orifice washer positioned in the flow stream. The syrup flow sensors serve to sense a differential pressure from which the flow rate of the syrup can be interpolated by the micro-controller.  
           [0007]    The vertical flow channel of the water body has a stepper motor secured to a top end thereof and a “V”-groove type flow regulator and valve seat at an opposite bottom end thereof. An actuating rod extends centrally of the vertical flow channel and is operated by the stepper motor to move linearly therein. The rod includes a tapered end for cooperative insertion through the center of a coordinately tapered central hole of the V-groove regulator. A tip end of the tapered rod end cooperates sealingly with a seat to regulate flow of the water past the seat and into the nozzle body. The stepper motor is connected to a suitable power source and its operation is controlled by the micro-controller.  
           [0008]    A solenoid having a vertically extending and operating armature is secured to a top end of the vertical flow channel of the syrup body. The armature is operable to move in a downward direction through the vertical syrup flow channel and has a distal end that cooperates with a seat formed in the nozzle body positioned centrally of that vertical flow channel at a bottom end thereof. The solenoid is also connected to a suitable power supply and controlled by the micro-controller.  
           [0009]    An outer housing is secured to the support plate and serves to cover and protect the valve body sections, actuating devices and an electronics board containing the electronic micro-controller based control. The valve can be actuated by various means including, a lever actuated micro-switch or one or more push switches on the front face of the valve.  
           [0010]    In operation, actuation of a valve switch causes the syrup solenoid to open and the stepper motor to retract the linear rod to a predetermined position away from its seat. The syrup and water then flow through the nozzle body to the nozzle and are subsequently mixed together for dispensing into a cup of other receptacle. As the water is flowing, it rotates the turbine flow sensor and the rotational speed thereof is translated into a flow rate by the micro-controller. At the same time, the differential pressure sensors are sensing the pressures on each side of the restricted orifice and the micro-controller is, based on that information, calculating a flow rate for the syrup. It will be appreciated by those of skill that the position of the linear rod tapered end vis a&#39; vis the v-groove regulator, changes the size of the opening leading to the nozzle body through which the water must flow. Thus, the flow rate of the water can be adjusted in that manner in proportion to the size of that opening whereby the stepper motor can be actuated to position the linear rod tapered end at any point between full open and full closed. Therefore, in the valve of the present invention, the micro-controller first determines the flow rate of the syrup and then adjusts the flow rate of the water accordingly in order to maintain a pre-programmed ratio between the two liquids at a preprogrammed or desired flow rate. A gross adjustment of the syrup flow rate is provided by the adjustment means in the nozzle body and serves to determine a range as, for example, between a high flow and low flow application, such as, between a 1½ or 4 ounces per second dispense rate.  
           [0011]    A major advantage of the preset invention is the combination of the adjustable linear actuation of the rod that interacts with v-groove regulator to regulate the flow rate of the water. This approach is quite accurate, is reliable and low in cost. Determining the flow rate of the water through the use of a turbine flow meter has also proven reliable and low in cost. A further major advantage of the present invention is the use of a microelectronic strain gage type differential pressure sensor approach for determining the syrup flow rate. Syrup has proven to be a difficult substance to work with owing in large part to its viscosity, the temperature sensitivity of that viscosity and that it can be corrosive and harbor the growth of microorganisms. The microelectronic sensors have been found herein to be suitable for use with beverage syrups in that they are able to accurately sense variations in the flow rate thereof without much effect as to viscosity changes, and are not degraded chemically over time. In addition, the particular mounting of the sensors requires a very small area of contact with the syrup resulting in a structure that does not cause any type of syrup build up or cleanliness concerns. The syrup flow sensing approach of the present invention provides the further advantage of also providing for a valve that is relatively compact, light in weight and low in cost.  
           [0012]    The ability of the valve of the present invention to be disassembled by hand, including the internal components of the water, syrup and nozzle bodies provides for ease of manufacture and repair thereby also reducing the resultant purchase and life costs thereof. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0013]    A better understanding of the structure, function, operation and the objects and advantages of the present invention can be had by reference to the following detailed description which refers to the following figures, wherein:  
         [0014]    [0014]FIG. 1 shows a perspective view of the valve of the present invention.  
         [0015]    [0015]FIG. 2 shows a further perspective view of the invention herein with the outer cover removed.  
         [0016]    [0016]FIG. 3 shows an exploded view of the valve herein and including a quick disconnect block.  
         [0017]    [0017]FIG. 4 shows a perspective view of the base plate.  
         [0018]    [0018]FIG. 5 shows a side perspective view of the water body assembly.  
         [0019]    [0019]FIG. 6 shows a cross-sectional view of the water body assembly.  
         [0020]    [0020]FIG. 7 shows a perspective view of the v-groove regulator  
         [0021]    [0021]FIG. 8 shows a top plan view of the v-groove regulator.  
         [0022]    [0022]FIG. 9 shows an enlarged plan cross-sectional view along lines  9   a  of FIG. 8.  
         [0023]    [0023]FIG. 10 shows an enlarged plan cross-sectional view along lines  9   b  of FIG. 8.  
         [0024]    [0024]FIG. 11 shows a perspective view of the syrup body assembly.  
         [0025]    [0025]FIG. 12 shows a side plan cross-sectional view of the syrup body assembly.  
         [0026]    [0026]FIG. 13 shows an enlarged perspective view of the syrup body.  
         [0027]    [0027]FIG. 14 shows a top plan view of the syrup body.  
         [0028]    [0028]FIG. 15 shows and enlarged cross-sectional plan view of the differential pressure sensor portion of the syrup body assembly.  
         [0029]    [0029]FIG. 16 shows and enlarged cross-sectional plan view of the flow washer.  
         [0030]    [0030]FIG. 17 shows an exploded perspective view of the nozzle body.  
         [0031]    [0031]FIG. 18 shows a top plan view of the nozzle body.  
         [0032]    [0032]FIG. 19 shows a bottom plan view of the nozzle body.  
         [0033]    [0033]FIG. 20 shows a perspective cross-sectional view of the nozzle body.  
         [0034]    [0034]FIG. 21 shows an exploded perspective cross-sectional view of the nozzle body, syrup flow adjustment insert and retainer.  
         [0035]    [0035]FIG. 22 shows a further cross-sectional view of the nozzle body as retained in the base plate.  
         [0036]    [0036]FIG. 23 shows an exploded perspective view of the syrup and water body assemblies along with the nozzle body.  
         [0037]    [0037]FIG. 24 shows a top plan view of the syrup and water body assemblies indicating their manner of attachment to the nozzle body.  
         [0038]    [0038]FIG. 25 shows a perspective view of the syrup and water body assemblies secured to the nozzle body.  
         [0039]    [0039]FIG. 26 shows a top plan view of the syrup and water body assemblies secured to the nozzle body.  
         [0040]    [0040]FIG. 27 shows a diagram of the flow characteristics of the grooved regulator of FIG. 29 a.    
         [0041]    [0041]FIG. 28. show a schematic representation of a cross-section of the regulator of FIG. 29 a.    
         [0042]    [0042]FIG. 29 a  shows a top plan view of an embodiment of a grooved regulator having four notches.  
         [0043]    [0043]FIG. 29 b  shows a top plan view of a grooved regulator having one notch.  
         [0044]    [0044]FIG. 30 shows a diagram of the flow characteristics of the grooved regulator of FIG. 32.  
         [0045]    [0045]FIG. 31. show a schematic representation of a cross-section of the regulator of FIG. 32.  
         [0046]    [0046]FIG. 32 shows a top plan view of a further embodiment of a grooved regulator having two notch pairs each pair having a different depth.  
         [0047]    [0047]FIG. 33 shows a diagram of the flow characteristics of the grooved regulator of FIG. 35.  
         [0048]    [0048]FIG. 34 show a schematic representation of a cross-section of the regulator of FIG. 35.  
         [0049]    [0049]FIG. 35 shows a top plan view of a further embodiment of a grooved regulator.  
         [0050]    [0050]FIG. 36 is a simplified schematic of the electronic control of the present invention.  
         [0051]    [0051]FIG. 37 shows a graphical representation of the operation of the stepper motor and syrup solenoid.  
         [0052]    [0052]FIG. 38 is a graphical representation of the allowable ratio error limits.  
         [0053]    [0053]FIG. 39 a flow diagram of the control logic of the present invention.  
         [0054]    [0054]FIG. 40 shows a perspective view of a ratio testing device. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0055]    The valve of the present invention is seen in FIG. 1 and generally referred to by the numeral  10 , and includes a removable outer protective shell  12 . Removal of shell  12 , as seen in FIGS. 2 and 3, reveals various internal valve components including a base plate  14 , a quick disconnect mounting block  16 , a syrup flow body assembly  18 , a water flow body assembly  20 , a nozzle body assembly  22  and a printed circuit board electronic control  23 . Base plate  14  includes a front push button control portion  24  having a plurality of diaphragm type switches  24   a - 24   e  for operating valve  10 . Switch  24   e  causes valve  10  to dispense for as long as it is operated/pushed. In the same manner, a lever arm  19  can alternatively be used to operate a switch, not shown, to cause valve  10  to dispense. As is well understood, arm  19  is pivotally suspended from base plate  14  and is typically actuated by pushing a cup to be filled there against followed by retraction of the cup once it is filled. Switches  24   a - e  are of the portion control variety wherein selection of a particular switch serves to operate valve  10  to dispense a preprogrammed volume of drink. It is also known to have the valve turned off automatically based upon a sensing that the cup is full.  
         [0056]    Base plate  14  also includes a vertical rear portion  25  having formed in a shelf area  25 ′ thereof two semi-circular annular grooves  25   a  and  25   b . Plate  14  further includes circuit board retaining slots  26   a  and a circuit board retaining clip  26   b  as well as a pair of nozzle body retaining clips  27 . A nozzle housing  28  is secured to nozzle body  22  through a hole in a bottom surface of plate  14 , the hole defined by a perimeter shoulder S. Quick disconnect  16 , as is well understood in the art, includes two barrel valves therein, not shown, for regulating the flow of water and syrup. The barrel valves are opened when the top and bottom trapezoidal insets  16   a  are received in correspondingly sized slots  16   b  in base  14  and locked thereto. Disconnect  16  includes fluid outlets  30   a  and  30   b  for fluid tight connection with syrup body assembly  18  and with water body assembly  20 , respectively. Further description of disconnect  16  and the details of its operation are seen by referring to U.S. Pat. No. 5,285,815, which disclosure is incorporated herein. As is known disconnect  16  is secured to a beverage dispensing machine, not shown, and provides for quick fluid connection of valve  10  thereto.  
         [0057]    As seen by now referring to FIGS.  5 - 10 , water body assembly  20  includes a plastic body portion  35  having a vertical flow regulating housing portion  35   a  and a horizontal flow meter housing portion  35   b . A stepper motor  36  is secured to a top end of housing portion  35   a  and operates a vertically positionable shaft  37 . In one embodiment of the present invention where the total flow rate is between 1 and ½ to 6 ounces per second, motor  36  operates on 3-5 volts DC and provides for a reversible shaft travel of 0.001 inch per step at a rate of 1 to 1000 steps per second. Shaft  37  extends through upper fluid sealing rings  38  and has a distal conical end  42  and a seating shoulder  43 . As seen in the enlarged views of FIGS.  7 - 10 , a specialized grooved fitting  44  is retained within a bottom end of housing  35   a  and sealed therein by an o-ring  46  received within a perimeter annular groove  48 . Fitting  44  is circular having a height or thickness represented by the letter “H”. Fitting  44  is formed by the drilling of a central hole or bore  50  there through having a diameter “D” followed by the formation of a plurality of V-shaped grooves or notches formed therein and extending downward from a top fitting surface  51 . In the disclosed embodiment, there are four grooves consisting of two deep grooves  52  and two shallow grooves  54 . The angular or cut away portion of grooves  52  represented by angular surfaces  56  extend to a bottom surface  58  of fitting  44 . The corresponding surfaces  60  of grooves  54  terminate at a point approximately midway of the height or thickness H of fitting  44 . The vertical or internal angular steepness of grooves  52  and  54  can be represented by angles A 1  and B 1  respectively. The width of the grooves  52  and  54  can be represented by top surface angles A 2  and B 2  respectively. A radiused or chamfered edge  62  extends around a top perimeter of grooves  52  and  54  and bore  50 . As seen in FIG. 7; shaft  37  is vertically positionable through fitting  44  and at its bottom most position shoulder  43  seats against a perimeter edge  64  of a circular seat  66 . It will be understood herein below that seat  66  is retained in nozzle body  22 .  
         [0058]    Water body portion  35   b  includes an inlet fitting  70  for receiving outlet  30   b  of quick disconnect  16 . Inlet  70  has an outer annular ridge  72  that serves to cooperate with annular groove  25   b  of rear plate portion  26 . A turbine type flow meter  74  is held within flow meter portion  35   b . Portion  35   b , with meter  74  therein, is then sealingly secured to body portion  35   a , by for example sonic welding, for fluid tight securing in flow cavity  75 . In addition, an o-ring  76  provides for further fluid isolation of the exterior of meter  74  from the water flow stream passing from inlet  70  into and through body portion  35   a . Flow meter  74  is of a turbine type, well known in the art, and in the beverage valve embodiment of the present invention, is selected to work in an aqueous environment in a flow stream varying between approximately 0.25 to 11 ounces per second, having a sensitivity of 6000 pulses per second and exposed to pressures from 0.0 to 580 psi. Also in the preferred embodiment, turbine flow meter  74  has and exciter voltage in the range of 5-24 volts and uses approximately 12 milliamps of current. includes a circuit board  78  formed as a disk having a central hole on which are mounted optical sensors for determining the rotation of the rotatively mounted turbine (not shown). Wires (not shown) extend from disk  72  and extend through holes  79  for connection to main circuit board  23 . As is understood, main control circuit board  23  embodies a micro controller that determines the rotation rate of the turbine of flow meter  74  and from that number calculates a flow rate of the water passing through flow portion  34 . It will be appreciated that the securing of meter  74  in body portion  35   b  and the sealing thereof to body portion  35   a  along with the use of o-ring  76  also serves to isolate circuit board disk  78  from any damaging fluid contact. Body portion  35   a  includes a pair of locking tabs  35   c  extending from a bottom end thereof  
         [0059]    As seen in FIGS.  11 - 16 , syrup flow body  18  includes a plastic flow body portion  80  having locking tabs  81 , an inlet end  82  having a perimeter annular ridge  84  for cooperating with corresponding groove 25   a  of base plate vertical portion  25 . Inlet  82  receives outlet  30   a  of quick disconnect  16  for providing syrup into a central horizontal flow channel comprised of a first channel portion  86   a  and a second channel portion  86   b . Channel portion  86   b  communicates with a fluid cavity  88  wherein a vertically extending flow channel segment  90  extends. Flow segment  90  defines a portion of a vertical flow channel  92  and has a proximal perimeter seat end  94 . A normally closed solenoid  96  operating at 24 volts dc is secured to a surface area  97  of body portion  80  and includes and armature  98  having a resilient seat end  98   a  for closing against seat  94 . Flow body  80  includes two circular recesses  100   a  and  100   b  that communicate fluidly to flow channel portions  86   a  and  86   b  through small orifices  102   a  and  102   b  respectively. Two pressure sensors, not shown, one associated with each recess  100   a  and  10   b , are positioned therein to be exposed to the flow of syrup through channel portions  86   a  and  86   b . The pressure sensors are of the well known pressure sensing diaphragm or micro-electromechanical (MEMS) type and in the disclosed beverage valve embodiment herein are selected to respond to pressures in the range of 0-100 psi. Such sensors in the preferred embodiment operate at 3 to 5 volts dc, and need to have an accuracy or pressure non-linearity of less than 1%. In the preferred form, the sensors are individually and separately mounted to a common circuit board  104  which includes the electronics and connectors  106  for communicating sensed pressure data to control board  23 . Ribbon type connectors, not shown, provide for the electrical connection from connectors  106  to board  23 . O-rings  108  provide for fluid tight sealing of the pressure sensors from the remainder of the board  104 . Board  104  is held in place in against a flat surface area  110  by suitable attachment means, such as, food grade adhesive, as well as by a retainer  112  which is snap fittingly secured to flow body  80 . As understood by referring to FIGS. 15 and 16, a flow washer  114  is retained at the intersection of flow channels  86   a  and  86   b  and has a thickness T, half the length of which is enlarged by a chamfered edge  118  extending at an angle C. A central bore  116  has a diameter of approximately 0.065 inch. In the preferred form, the chamfered edge side of washer  114  faces in an upstream direction as will be understood by the direction of syrup flow indicated by the arrows of FIG. 15. As is known, the chamfered edge  118  serves to reduce the apparent thickness T. Those of skill will understand that the chamfer typically can face in a down stream direction providing the upstream edge is sharp, i.e. of a radius substantially less than the diameter of the orifice.  
         [0060]    As seen in FIGS.  17 - 23 , nozzle flow body assembly  22  includes retainer stops  120   a  and  120   b  each defining tab receiving grooves  122   a  and  122   b  respectively. Annular recesses  124   a  and  124   b  serve to retain resilient fluid sealing washer and water seat  66  and a further resilient fluid sealing washer  126  respectively and are surrounded by flat circular areas  127   a  and  127   b . A vertical syrup passage  128  fluidly connects with a horizontal syrup passage  130 , which, in turn, fluidly communicates with a central syrup discharge outlet  132 . Similarly, a vertical water passage  134  fluidly connects with a horizontal water passage  136 , which, in turn, fluidly communicates with a water discharge outlet  138 . A syrup flow adjustment piece  140  includes a protruding edge portion  142 , a central bore  144  and a v-shaped slotted opening  146  extending there through into the bore  144 . Adjustment piece  140  is held within syrup discharge outlet  132  wherein edge portion  142  is inserted within rotation limiting slot  148  and is held within outlet  132  by a disk shaped retainer  150 . Retainer  150  includes a neck portion  152  for close fitting insertion into outlet  132  and includes a water flow hole  154  having an annular ridge  156  for insertion into water discharge outlet  138 . Retainer  150  is permanently secured to nozzle body  22  by, for example, sonic welding thereto around its perimeter edge  158  and by sonic welding between outlet  138  and ridge  156 . As seen in FIG. 16, adjustment piece  140  includes slots  160  in the bottom end surface thereof. Nozzle body  22  also includes a pair of snap fitting tabs  162  for insertion into and snap-fitting securing thereof with retainers  27  of base plate  14 . A fluid mixing insert  170  includes a neck portion  172  for insertion into retainer  150  and is fluidly sealed there with by and o-ring  174 . Mixing insert includes a conical surface area  176  and two horizontal circular plates  178  and  180  positioned there below. Plates  178  and  180  include a plurality of passages  182  there through and the perimeter edges thereof are closely adjacent an interior flow surface  184  of nozzle housing  28 . As will be understood by those of skill, nozzle housing  28  is fluid tightly secured to nozzle body  22  by a twisting engagement of tabs  186  thereof with retainers  164  thereof against an o-ring  188  there between. Mixing insert  170  also includes a central syrup channel  190  for directing syrup from outlet  132  to angled exit orifices  192 .  
         [0061]    By referring to FIGS.  23 - 26 , the manner of assembly of syrup flow body assembly  18 , water flow body assembly  20  and nozzle body assembly  22  can be understood. In particular, the lower end of syrup body portion  35  is centered on and pressed against surface area  127   a  after which it is turned counterclockwise as indicated by the arrows CC in FIG. 22 wherein tabs  81  fit within grooves  122   a  of stops  120   a . This rotational movement of syrup body  18  is limited by stops  120   a  to place syrup assembly  18  in the proper orientation. In a similar manner, the lower end of water body portion  35   a  is centered on and pressed against surface area  127   b  after which it is turned clockwise as indicated by arrows CW wherein tabs  35   c  fit within grooves  122   b . This rotational movement of water flow body  20  is limited by stops  120   b  to place it in the proper orientation. The assembly of the three flow bodies is then lowered into plate  14  wherein snap tabs 162  are received within retainers  27  providing for snap-fitting securing there between. It will be understood that a lower portion of annular ridges  84  and  72  of flow bodies  18  and  20  will. rest on and be received in annular grooves  25   a  and  25   b  respectively. Nozzle housing  28  is then secured to nozzle body  22  in the manner above described capturing mixing insert  170  there between. Control electronics board  23  can be fit into slots  26   a  wherein retainer  27  snap fits into a slot, not shown, in board  23  thereby retaining board  23  in the vertical orientation as seen in FIG. 2. Those of skill will understand that the various electrical connections between flow sensor  74 , pressure sensing board  106 , stepper motor  36 , solenoid  96  and circuit board  23  can be facilitated by releasable plug-in connectors. Housing  12  can then be secured to plate  14  by any of a variety of snap fitting releasable type securing means.  
         [0062]    As is well understood, the general operation of valve  10  secured to a power supply to run stepper motor  36 , solenoid  96  and-control board  23  and to a quick disconnect  16 , which disconnect  16  is suitably secured to a beverage dispenser and fluidly connected to a source of syrup and diluent. When valve  10  is secured to disconnect  16  pressurized sources of syrup and diluent are supplied to valve  10 . When a suitable dispense button is selected by use of one of switches  24   a - d , a particular volume of drink is requested as is previously programmed in the control of circuit board  23 . Control board  23  signals stepper motor  36  to withdraw shaft  37  from contact with seat  66  thereby permitting the flow of water through body portion  34  and into nozzle body assembly  22 . After a short delay, to be explained and described in greater detail below with regard to the specific operation of valve  10 , solenoid  36  is opened permitting a flow of syrup through syrup body  80  to nozzle body assembly  22 . The syrup and water then flow to mixing insert  170  and exit nozzle housing  28  into a cup held there below. As is well understood the water and syrup flows must flow at a pre-established ratio, for example, five parts water to one part syrup. Valve  10  accomplishes the maintenance of this ratio by simultaneously determining the flow rate of the syrup and the water and adjusting the flow rate of the water to the syrup. It will be appreciated by those of skill that the flow rate of the syrup is determined by a differential pressure flow rate sensor as is comprised of flow sensor chip  104 , the flow washer  115  and flow channel portions  86   a  and  8   b . It will be understood that as syrup flows through the central orifice of washer  115 , different fluid pressures are presented to the up and down stream pressure sensors positioned on board  104  and above orifices  102   a  and  102   b  respectively. A micro-controller of control board  23  is programmed therewith and with variously experimentally determined data contained in lookup tables in order to permit the calculation of the actual syrup flow rate. At the same time as the syrup flow rate is being determined the water flow rate is being measured as a function of the rotational speed of the turbine flow sensor  74 . This water flow rate is determined by the control of board  23  and compared with the calculated syrup flow rate in real time. If the ratio there between is not as is desired where, for example there is an excess of water, the micro-controller signals stepper motor  36  to move shaft  37  in a downward direction positioning conical surface  42  thereof closer to seat surface  64  of seat  66 , thereby reducing the opening there between and lowering the water flow rate. Of course, those of skill will realize that micro-controller must be able to provide rotational instructions to stepper motor  36  to effect the desired water flow rate adjustment. As is known, stepper motors, such as motor  36 , can be signaled to rotate through a set number of 360 degree rotations and/or fractions thereof that correspond to a know linear distance movement of the shaft thereof.  
         [0063]    If a standard circular valve seat is used having no regulator  44  there above, the flow rate there through is not linear. In fact, a major problem has been that the flow rate as a function of the separation between the seat of a standard orifice and the effective end of the shaft can be complicated to determine and to control. However, the flow regulator  44  shown herein has been found to establish a substantially linear relationship between the shaft  37  position vis a&#39; vis the seat and the fluid flow rate. As seen in FIG. 28, a generalized regulator  180  is shown in cross section wherein flow rate there through is depicted in the graph of FIG. 27. As a shaft  182  moves in the direction of arrow A of FIG. 28, the flow rate of fluid through regulator  180  is shown in the graph of FIG. 27 to increase linearly. The slope of that line can be understood to be a function of the size or number of grooves  184  in regulator  180  or  180 ′, as illustrated in FIGS. 29 a  and  29   b . The slope can be understood to be lower for regulator  180 ′as seen in the dashed line of FIG. 27. FIGS.  30 - 35  show the effect of variously configured grooves. Regulator  186  of FIG. 32 includes, as does regulator  44 , two sets of grooves, shallow grooves  188  and deep grooves  190 . When shaft  182  reaches the point within regulator indicated by vertical line L of FIG. 31, the grooves  188  begin to contribute to the fluid flow and hence increase the slope of the fluid flow as indicated at the slope change point  192  of FIG. 30. It can now be appreciated that the increase if flow area provided by the additional set of grooves allows shaft  37  to travel through a shorter linear distance but still provide the desired increase in flow rate. The angles A 1  and A 2  and B 1  and B 2 , seen in FIGS.  7 - 10 , provide for increased flow rate in proportion to increase an in size thereof. Thus, the larger the grooves and the larger the bore  50 , the more flow is permitted as the shaft withdraws. Of course, those of skill will understand that all such dimensions and angles are highly variable depending on the flow rate range, the desired flow accuracy, the travel of the linear actuator and the like. In a beverage dispense environment of 1 and ½ to 6 ounces per second, bore  50  can be approximately 0.185 inch.  
         [0064]    As seen in regulator  194  of FIG. 34, a single groove  196  includes a first sloped portion  196   a  a horizontal or linear portion  196   b  and a further sloped portion  196   c . As seen in the graph of FIG. 33, these three groove sections correspond with the flow rate curve portions  198   a ,  198   b  and  198   c  respectively. Thus, as shaft  182  withdraws from regulator  194  the flow rate first increases do to the widening effect of groove portion  196   a . The flow rate then levels off as groove portion  196   b  represents a constant non increasing flow area. The flow rate then starts to increase as the shaft is withdrawn past groove portion  196   c  wherein the flow area is again increasing. FIG. 35 shows a regulator  200  having a V-shaped groove  202  and also shows in dashed outline various other regular geometric groove shapes such as a U-shaped groove  204   a , a square shaped groove  204   b  or a trapezoidal shaped groove  204   c . It will be understood that these other groove shapes can be angled to provide for increasing grooved area and greater fluid flow as the shaft  182  retracts. Thus, FIG. 35 illustrates that any of a wide variety of groove cross-sectional shapes and configurations can be used depending upon to achieve a linear flow as a function of shaft position within a grooved regulator. Thus, this linearity permits a relatively straightforward calculation by the control of board  23  as to the distance to move shaft  37  in or out to follow the sensed syrup flow rate. Therefore, the water flow rate is continually being adjusted in real time as a function of the sensed water flow rate and syrup flow rate.  
         [0065]    A more detailed understanding of the manner of the operation of the control of the operation of the present invention can be had by referring to FIGS.  36 - 39 . As seen in FIG. 36, a simplified schematic of the present invention shows control board  23  including a power supply  210  and a micro-controller  212 . Switches  24   a - e , turbine  74  and differential flow sensor board  104  provide input to micro-controller  212 . A connection port  214  is also connected to micro-controller  212  for purposes of facilitating adjustment of the operation of valve  10  as will be described in greater detail herein below. Microprocessor  212  is also connected to stepper motor  36  and solenoid  96  for controlling the operation thereof. Power supply  210  includes a capacitor array  215  for emergency powering of the stepper motor  36 . If power should fail, syrup flow will automatically stop as solenoid  96  is normally closed, i.e. power is required to hold it open. However, those of skill will understand that stepper motor  36  will remain at whatever position it is at when power is interrupted. Therefore, capacitor array  215  provides power to close stepper motor  36  if power is sensed to have failed.  
         [0066]    As seen in FIG. 37, a graph of the operation of the stepper motor  36  is represented by solid line  216  and syrup solenoid  96  is represented by a dashed line  218 . Stepper motor opens at a time T 1  and the water flow subsequently ramps up to a desired flow rate at time T 3 . At time T 3 , stepper motor movement stops. Syrup solenoid  96  opens at a time T 2  after the initiation of water flow, but prior to time T 3 , and quickly reaches a peak flow. This delay in the initiating of the syrup flow is necessary as those of skill will appreciate that stepper motor  36  can not open as quickly to it full flow position as can solenoid  96 . Thus, if they were opened simultaneously, the finished drink would be too rich in syrup, the desired in cup ratio not being achieved. Therefore, initiation of a dispense into a cup by, for example, the pressing of switch  24   e , signals micro-controller  212  to first operate motor  36  and then to open solenoid  96 . At the close of dispense when the cup is full, switch  24   e  can be released causing the reverse to occur. Specifically, at time T 4  motor  36  begins to close and then is fully closed at time T 6 , and solenoid  96  is signaled to close at time T 5  there between. This staggering at closing, for the same reason stated above for opening, also serves to maintain the proper in cup ratio of syrup to diluent. The particular staggering time of the stepper motor and solenoid are dependent upon the type of stepper motor and solenoid used, the desired ratio between syrup and diluent water and the desired total dispense or flow rate of the two liquid combined. However, in a drinks dispense environment where the stepper motor opens to the first desired position in approximately 0.33 second, the solenoid is opened midway thereof, i.e. approximately 0.165 second.  
         [0067]    A further detailed explanation of the control of the valve of the present invention can be had by referring to FIGS. 38 and 39. As illustrated graphically in FIG. 38, there exists a known or predetermined in cup target ratio N. If the ratio of the drink is 5 parts syrup to 1 part carbonated water, then the total volume of syrup and carbonated water in the cup must be ideally in that proportion, or within an acceptable error thereof. This is achieved by having micro-controller  212  keep track of two ratios, an instantaneous ratio and a total dispensed or in cup ratio. Thus, processor  212  is determining an instantaneous flow rate as a function of the differential pressure sensor determination of the syrup flow rate and the water turbine sensed flow rate of the water at a particular moment in time. Those of skill will understand that controller  212  makes such calculations many time per second and in a particular embodiment of the invention, approximately 100 times per second. The in cup ratio is simply a calculation comprising a summation of the total syrup and water flow as a function of the known flow rates thereof as have occurred during a particular pour. Thus, at any point in time, processor  212  knows the total volume that has been dispensed, the ratio of that total dispense and what the ratio being dispensed at any particular point in time is. Processor  212  is programmed with an allowable positive in cup ratio error E+ and an allowable negative in cup ratio error E− creating an in cup error band indicated by the arrow B 1  in FIG. 38. Processor  212  is also programmed with an allowable positive instantaneous ratio error I+ and an allowable negative instantaneous error I− creating an instantaneous error band indicated by the arrow B 2  in FIG. 38. With the foregoing in mind, a further understanding of the operation of the control of the present invention can be had by referring to the flow diagram of FIG. 39. A pour of beverage from valve  10  into a suitable container position below nozzle  28  is initiated by an operator selecting one of the pour initiation switches  24   a - e . Pour initiation is seen in block  220 . At block  222 , processor  212  determines if the in cup ratio is greater than or equal to E+, less than E−, or within that error band, i.e. less than E+ and greater than E−. If the in cup ratio is greater than or equal to E+, at block  224  the instantaneous ratio is determined. If the instantaneous ratio is greater than I−, at block  226  stepper motor  36  is activated to move shaft in the closing direction reducing water flow. conversely, at block  228  if the instantaneous ratio is less than or equal to I− then no change is made to the position of stepper  36 . If at block  222  it is determined that the in cup ratio is less than E− then at block  230  the instantaneous ratio is also calculated. If that ratio is less than or equal to I+, then at block  232  no change is made to the position of stepper  36 . However, if the instantaneous ratio as checked at block  230  is less than I+ then the drink is too syrup concentrated at that point and stepper  36 , at block  234  is made to move to increase water flow. Those of skill will understand that the instantaneous ratio is being constantly calculated and occurs as the stepper motor  36  is moving either towards its seated closed position to make the ratio less dilute or towards its full open position to make the ratio more dilute. Thus, the control cycle back through block  222  until the sensed instantaneous ratio is within the in cup ratio error band. At that point at block  236  the instantaneous ratio is again determined and if it is less than E− the in cup ratio is calculated at block  238 . If the in cup ratio is less than N, stepper motor  36  is operated at block  240  to increase the water flow. Conversely, if the in cup ratio at block  238  is greater than or equal to N, then at block  242  no change is made to the stepper motor position. If, at block  236  the instantaneous ratio is determined to be greater than E+ the in cup ratio is calculated at block  244 . If, at block  246  the in cup ratio is less than or equal to N stepper motor  36  position is not changed. Conversely, if the in cup ratio at block  244  is greater than N, then at block  242  stepper motor  36  is operated to reduce water flow. If at block  236  the instantaneous ratio is equal to N, then at block  250  no change is made to the position of stepper motor  36 . Those of skill will understand that the control as shown in FIG. 39 permits the instantaneous ratio to first be brought within a wider instantaneous ratio band and then to be brought within a narrower in cup ratio error band. This approach was found to provide for a relatively smooth operation whereby the desired ratio N was approached without the need for a lot of movement by stepper motor  36 . The position that motor  36  is first opened to is determined by memorizing its position during the previous pour at the point at which the in cup ratio and the instantaneous ratio are equal or the closest. If there exists no previous pour data, a default position is preprogrammed. When the dispense from valve  10  is manual, as by the use of switches  24   e  or lever arm  19 , dispensing is stopped when such switches are released.  
         [0068]    With respect to the environment of a beverage dispense at a ratio of 5 to 1, the E+-E− range is generally set to plus or minus 0.1. Thus, the acceptable in cup ratio is between 4.9 to 1 to 5.1 to 1. The instantaneous ratio is set to plus or minus 0.5 wherein the acceptable I+ to I− range is 5.5 to 1 to 4.5 to 1. It can be appreciated that the wider acceptable instantaneous ratio permits a more gradual approach to the desired ratio in the sense that any large swings between essentially an all syrup or all water dispense as a response to the sensed opposite condition, are greatly reduced. Also, by preventing the initiation of any such strong oscillations between very dilute and very concentrated, stratification of water and syrup in the cup is similarly reduced. Thus, the drink in the cup is much more uniform, and consequently, during a dispense the flow of beverage from the nozzle is also more uniform, i.e. not showing alternating bands of clear and dark as water rich and syrup rich portions are dispensed respectively. The use of both instantaneous ratio and in cup ratio information can also be understood to permit a rather rapid and accurate approach to the desired water flow/stepper motor flow position vis-a-vis the sensed syrup flow by diminishing any large fluctuations or undesired hysteresis between very dilute and very concentrated flows. Typically valve  10  will come within an acceptable in cup beverage ratio within 0.5 seconds, thus dispense volumes greater than 0.75 to 3.0 ounces, depending upon the desired flow rate, will have an acceptable in cup ratio. In a “top-off” event a small amount of beverage is added subsequent to the termination of a pour, but immediately there after, to fill the cup to a desired level. Such is typically due, in the case of a carbonated beverage, to a recession of foam produced by the primary pour. It can be appreciated that the present invention will oftentimes come within ratio during the top-off pour. And, since the last position of the stepper motor is kept in memory and applied to the subsequent drink and the top-off occurs essentially immediately after the primary pour where the syrup flow parameters have also not generally changed, any pour of less than 0.5 seconds will be quite close to the desired in cup ratio. Of course, to the extent there exist any discrepancies in the ratio of the added beverage and the target ratio, the small volume of the added aliquot of liquid does not appreciably impact the overall in cup ratio.  
         [0069]    It can now be appreciated that selection of a drink volume using switches  24   a - d  signals micro-controller  121  to determine when the total volume dispensed is equal to the predetermined and selected small, medium, large or extra large volume. Thus, a further block  252  questions if that pre-selected total volume has been reached. If it has, then dispensing is stopped at block  254 . Due to variations in the manufacture of certain elements, such as, the turbine flow meter, the differential pressure sensors and the like, it was found that there can exist a difference between the ratio that the valve is set at and the actual in cup ratio that is dispensed. Thus, valve  10  can be adjusted or zeroed in through an actual pour test. As seen in FIG. 40, a brix cup  260  is shown comprising a clear plastic dual chambered cup having a syrup volume side  262 , a water volume side  264  and a divider  266  there between. As is known a specialized separating nozzle is  268  is used in place of the regular nozzle  28  and insert  170 . Nozzle  268  includes a tube  270  for insertion into the syrup discharge hole and directs the stream of syrup to syrup container portion  262 . As is also understood, water flows around tube  270  and down into water container portion  264 . In operation, valve  10  is actuated and allowed to dispense until the water reaches a particular level as is indicated by the graduation marks  272 . Since the syrup stream is separated from the water, its volume can also be determined by ascertaining its level. By simply dividing the water volume by that of the syrup the ratio there between can be calculated. If for example, a 5 to 1 ratio was desired however a 4.8 to 1 ratio was dispensed, then the software of micro-controller  212  must be adjusted to compensate therefor. This is done by connection of a device to port  214 . Such a device can be a hand held computer or the like having the ability to increment the ratio set point of the software control up or down as is needed upon an initial set up. It is also then possible thereby to subsequently set valve  10  to a different ratio wherein the software will automatically do so and take into account any such initial set up adjustments.  
         [0070]    Valve  10  can be designed to dispense at various dispense rates, such as, 1½ ounces per second, 4 ounces per second and 6 ounces per second. However, it was found that, since the syrup flow rate can not be adjusted during a dispense, it is important that it be capable of being adjusted within various flow ranges suitable for the particular total drink flow desired. The control would otherwise have difficulties in maintaining the correct ratio if the water and syrup flow rates were not at least generally matched. This gross adjustment of the syrup flow is accomplished by adjustment of insert  140 . As can be understood triangular shaped slot  146  is presented towards syrup orifice end of syrup flow channel  130 . As insert  140  is rotated about its central bore axis, more or less of the slot  146  is presented thereto thus permitting a greater or lesser flow respectively of syrup there through. Thus, rotation of insert  140  by a tool inserting into slots  160 , after removal of nozzle housing  28  and the mixing insert, permits such gross adjustment of syrup flow. The aforementioned brixing cup  260  and adjustment nozzle  268  can be used to set the desired syrup flow rate.  
         [0071]    A further advantage of the present invention can be seen to include the manner of assembly and disassembly thereof. When water body assembly  18  and syrup body assembly  20  are connected to nozzle body assembly  22  and secured to base  14 , it will be appreciated that ridge  72  of water body assembly  18  and ridge  84  of syrup body assembly are received in annular grooves  25   b  and  25   a  respectively. Furthermore, when quick disconnect is connected to base plate  14  the fluid coupling inserts  30   a  and  30   b  thereof are received in water body inlet end opening  70  and syrup body inlet end opening  84  respectively. This connection strategy serves to hold water body  18  and syrup body  20  in place as neither can be rotated. Thus, neither can be removed when fluidly connected to pressurized sources of water and syrup. To be removed quick disconnect must first be removed, but it can not be removed unless the barrel valves thereof have been closed. Thus, valve  10  can not be disassembled unless there exists no fluid pressure thereto. Clips  27  also serve to hold serve to hold the entire water, syrup and nozzle assembly in place joining thereof to base  14 . It can also be understood that the entire valve can be easily assembled and disassembled by hand. Moreover, stepper motor  36  is a permanent portion of the water body assembly as is turbine flow meter  74 . Thus, any failure of that component simply involves change out with a new replacement. Such is also the case for the syrup body  20 , the nozzle body  22  and the circuit board  23 . Thus, the present invention is fully modular and easily and inexpensively repaired and serviced.  
         [0072]    Valve  10  has been shown and described herein in its preferred beverage dispensing valve embodiment. However, those of skill will appreciate a wide variety of liquid pairs can be dispensed there from. It will also be apparent to those of skill that various modifications can be made to the present invention without exceeding the scope and spirit thereof. For example, a variety of flow sensors are known that could be substituted for turbine flow sensor  74  and/or differential pressures flow sensor  104 , such as, coreolis and ultrasonic flow sensors. A “mechanical” sensor of the turbine type wherein the flow of water imparts a rotation thereto has been found to be sufficiently accurate, reliable and low in cost when applied to sensing water flow in the present invention. The differential pressure sensing of the syrup has proven to be more accurate with the higher viscosity liquids such as a beverage syrup. Moreover, such sensing approach has also proven reliable, acceptably accurate and low in cost. Those of skill will understand that various embodiment of the invention herein could use a turbine flow meter on both the diluent and concentrate side, or a differential pressure flow sensor on each side, or indeed, could reverse the sensors and use a turbine on the concentrate side and a differential pressure flow sensor on the diluent side. Such selections would depend greatly upon the physical nature of the fluids being combined, their individual anticipated flow rates, their ratio of combination, accuracy required and the like. It will also be apparent to those of skill that a linear actuating means r, such as, a linear solenoid or pneumatic actuator could be substituted for stepper motor  36 . The functional requirement being that shaft  37  is capable of being moved incrementally and held at a variety of points between and including a fully open and a fully closed position.