Abstract:
An apparatus for producing a chilled or partially frozen beverage often referred to as a slush beverage. A variety of apparatuses have been designed to produce chilled beverages as well as to produce beverages which are in a “slush” form. Some of these apparatuses are referred to as “granita” machines. Such apparatuses can be used to produce slush beverages from a variety of products including fruit juices, coffee-based beverages, tea-based beverages, as well as beverages containing alcohol. Such apparatuses includes a chilling structure, and some form of blade or auger which moves relative to the chilling portion to strip the frozen product off and circulate the beverage along the chilling portion. Circulation of the beverage along the chilling portion helps to reduce the temperature of the beverage mixture thereby approaching a slush consistency.

Description:
CROSS REFERENCE 
     This patent application is a continuation-in-part of U.S. patent application Ser. No. 09/058,449 filed Apr. 18, 1998, now U.S. Pat. No. 6,058,721 the disclosure of which is hereby incorporated by reference. U.S. patent application Ser. No. 09/058,449 claims the benefit of domestic priority of United States Provisional Application No. 60/044,704, filed Apr. 18, 1997. 
    
    
     BACKGROUND 
     The present invention relates to an apparatus for producing a chilled or partially frozen beverage often referred to as a slush beverage. 
     A variety of apparatuses have been designed to produce chilled beverages as well as to produce beverages which are in a “slush” form. Some of these apparatuses are referred to as “granita” machines. Such apparatuses can be used to produce slush beverages from a variety of products including fruit juices, coffee-based beverages, tea-based beverages, as well as beverages containing alcohol. Such apparatuses include a chilling portion, and some form of blade or auger which moves relative to the chilling portion to strip the frozen product off and circulate the beverage along the chilling portion. Circulation of the beverage along the chilling portion helps to reduce the temperature of the beverage mixture thereby approaching a slush consistency. 
     A variety of problems have arisen with the prior art such that there is a need for an improved chilled beverage producing apparatus. One problem that arises in the prior art is that the temperature control system results in substantial wear and tear on the motor and drive assembly. As a result of the wear and tear, the motor and drive housing may tend to leak lubricant from its gear box and substantially shorten the life of the motor. 
     Slush beverages or granita have a consistency which is achieved by controlling a combination of the temperature of the liquid and the solid content in the liquid. For example, the solids content may be in the form of coffee solids, as well as sugar or fruit syrup solids. Prior art apparatuses typically use torque to sense the consistency of the slush mix as it approaches a freezing point. The torque is sensed by twisting of the motor itself and pivoting, thereby tripping a switch coupled thereto. The switch deactivates the cooling system. 
     When the beverage mixture approaches a desired consistency, the auger motor may tend to cycle on and off frequently. The frequent cycling on and off produces wear on the motor as well as increases the length of time required to freeze the beverage solution. Increased freeze time requires increased set up time and thereby increases the labor cost associated with an operation using such a machine. Additionally, an increased freeze time also increases the lead time in order to produce additional slush beverage when additional beverage mixture is added to the apparatus. 
     Prior art devices also may include an internal and external auger positioned in relation to the chilling portion. In such a configuration, the chilling portion includes a tubular drum with refrigeration coils that are retained within the wall of the drum. An internal auger rotates relative to a cavity in the drum to drive beverage mixture therethrough. An external auger rotates relative to the external surface to move beverage solution thereagainst. While such configuration may be useful, it requires substantial maintenance as well as increases the difficulty in installation and repair of the apparatus. 
     The prior art devices are difficult when it is necessary to adjust the consistency of the slush. In other words, if an operator wishes to increase or decrease thickness of the consistency of the slush, the apparatus must either increase its chilling effect or reduce its chilling effect. Such adjustment is made by adjusting a screw and spring arrangement associated with the rotation of the motor. The spring is difficult to adjust and is typically located within the housing of the apparatus. Such adjustment is inconvenient and very cumbersome to accurately monitor while operating the apparatus. 
     Prior art devices also require an inordinate set up time. For example, at the beginning of an operating day, the prior art apparatus must be started up and the solution refrozen. Alternatively, the mixture may be maintained in its frozen state. An apparatus is not known to provide the ability to maintain the beverage mixture at a desired chilled state. Typically, the machine is turned off and the chilling process must be started anew at the beginning of each day. 
     Another problem with the prior art is that the controls are positioned on a front face panel of the machine. While the controls may be provided in a touch panel arrangement, the beverage mixture is still prone to splash and accumulate on such surfaces. As such, cleaning is required of these controlled surfaces. However, cleaning will inherently cause accidental activation of the switches thereby possibly subjecting the mixture to undesired unintentional adjustment. 
     Prior art apparatuses also make it difficult to install, maintain and repair the chilling portion and auger associated therewith. As described above, some prior art apparatuses include augers both internally and externally of the chilling portion. Such structures are inherently difficult to work on. However, external auger structures used with prior art devices are also difficult as they require complicated rod assemblies and fasteners. It would be desirable to provide an auger assembly which is easily installed, easily removable for cleaning, and can be easily assembled for repair. Additionally, it would be desirable to provide an auger assembly which does not employ hardware as such hardware may be prone to disengagement and dispensing into a beverage mixture. 
     It is desirable to provide an apparatus which includes a hopper of sufficient capacity to provide a reasonable amount of slush beverage on demand. Such hoppers should be covered in order to prevent contamination by airborne particles, maintain sanitation and to prevent splashing. Prior art devices employ a cover which are uni-directional such that they are oriented for display in only one direction. Additionally, such covers have an internal cover line which requires additional cleaning and is prone to frequent contact with the slush beverage. Contact occurs as a result of the formation of a churning hump. The churning hump results from the auger driving the slush beverage from the rear of the hopper towards the front of the hopper. The need to clean the internal surfaces of this cover require additional labor time and may not always occur. 
     A slush beverage apparatus as described hereinabove and as will be described in greater detail with regard to the present invention requires the cooling of a beverage in a hopper which has some surface area exposed to ambient atmosphere. As a result, it is common for condensate to accumulate on the exterior surfaces of the hopper. The condensate drips from the hopper and is accumulated and drained away. Prior art apparatuses have positioned air flow pattern such that air is required to flow from side to side of the machine in order to provide air flow to move the condensate. The air flow is also important in order to flow over a condenser coil as required by the coolant system. However, the side to side air flow creates a problem in the food service industry where floor space or counter space is at a premium. In this regard, the prior art design prohibits placing the slush beverage dispenser flush against walls or other apparatus as the side must be exposed for cooling and evaporation purposes. 
     As described above, there are numerous problems with the prior art which it would be desirable to solve. Heretofore, it is unknown to Applicant that these problems have been solved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The organization and manner of the structure and function of the invention, together with the further objects and advantages thereof, may be understood by reference to the following description taken in connection with the accompanying drawings, wherein like reference numerals identify like elements, and in which: 
     FIG. 1 is a top, front, left-hand perspective view of a slush beverage apparatus of the present invention; 
     FIG. 2 is a front elevational view of the apparatus as shown in FIG. 1; 
     FIG. 3 is a right-side, partial fragmentary elevational view of the apparatus as shown in FIGS. 1 and 2; 
     FIG. 4 is an enlarged left-side, elevational view of the apparatus as shown in FIGS. 1-3; 
     FIG. 5 is an exploded, perspective view of a hopper assembly of the present invention; 
     FIG. 6 is a partial exploded view of a housing and chassis assembly of the present invention; 
     FIG. 7 is an exploded, perspective view of a motor and housing assembly; 
     FIG. 8 is an exploded, perspective view of an auger assembly, chiller assembly, and motor shaft assembly; 
     FIG. 9 is a partial fragmentary, cross-sectional, side elevational view of the chiller assembly taken along line  9 — 9  in FIG. 8 showing a refrigeration coil retained within a cavity of a cooling drum; 
     FIG. 10 is a partial fragmentary, cross-sectional, side elevational view taken along line  10 — 10  in FIG. 9 in which insulation has been removed from the cavity of the cooling drum to better show the configuration of the refrigeration coil retained therein; 
     FIG. 11 is an enlarged, partial fragmentary, cross-sectional view showing thermally conductive epoxy applied to the refrigeration coil to increase the thermal conductivity between the coil and a wall of the cooling drum; 
     FIG. 12 is an exploded, perspective view of the motor shaft assembly; 
     FIG. 13 is a partial fragmentary, cross-sectional, side elevational view of a motor for attachment to the motor shaft assembly to drive the auger externally of the cooling drum; 
     FIG. 14 is an enlarged, partial fragmentary, cross-sectional, side elevational view of a torsion spring assembly for sensing the rotation of and torque on the motor shaft assembly. 
     FIG. 15 is a partial fragmentary, cross-sectional, side elevational view taken along line  15 — 15  in FIG. 14 showing protrusions used in sensing the torque on the motor shaft; 
     FIG. 15A is a top plan view taken along line  15 A— 15 A as shown in FIG. 15; 
     FIG. 16 is an enlarged exploded perspective view of the auger assembly; 
     FIG. 17 is a front elevational view of an auger nose component; 
     FIG. 18 is a side elevational view of one auger section used in constructing the auger; 
     FIG. 19 is a right-side elevational view of the auger as shown in FIG. 18 showing an interlocking receptacle used in assembling the auger assembly; 
     FIG. 20 is a left-side elevational view of the auger section as shown in FIG. 18 showing an interlocking protrusion which can be coupled with the interlocking recess as shown in FIG. 19 when assembling the auger sections as shown in FIG. 16; 
     FIGS. 21-24 are auger latch bars which are attached to necked areas on the auger assembly for retaining spacing of the auger blade portion and maintaining structural rigidity of the auger assembly, FIGS. 23 and 24 include a perpendicular end scrapper which is positioned toward the rear of the chiller portion for initiating movement of beverage solution along the cooling drum upon rotation of the auger; 
     FIGS. 25-27 show a hopper cover assembly in which a cover liner (FIG. 26) is removed from a hopper cover (FIG.  25 ), shown in cross-section, show the relationship between these components and the attachment structures for mounting the hopper cover assembly on the mouth of a hopper (FIG.  27 ); 
     FIGS. 28-31 show a top, front, partial fragmentary, cross-sectional, side elevational view, and a rear view of a control panel drawer as used in the present invention; 
     FIG. 32 is a diagrammatic illustration of the coolant system employed in the present invention; and 
     FIG. 33 is an electrical schematic of the control system employed in the present invention. 
    
    
     DESCRIPTION 
     While the present invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, an embodiment with the understanding that the present description is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to that as illustrated and described herein. 
     With reference to the figures, a chilled or slush beverage apparatus  30  is shown in perspective in FIG.  1 . The beverage apparatus  30  includes at least one hopper assembly  32  which is retained on a housing  34 . As will be described in greater detail hereinbelow, the housing  34  includes a mixing assembly and a coolant system  200  (see FIG.  32 ). The mixing assembly includes an auger drive motor  36  and a mixer of auger assembly  38 . The auger drive motor  36  as mentioned above drives the auger assembly  38  which is positioned proximate to a chiller assembly  40 , both being retained within a corresponding hopper assembly  32 . It should be noted that while a two-hopper apparatus is shown in FIG. 2, it may be desirable to provide a single hopper as well as three or more hoppers. 
     Briefly, the apparatus  30  is operated by placing a beverage solution in a selected hopper  42  of the hopper assembly  32 , positioning a cover assembly  44  on top of the hopper  42  and activating the apparatus  30 . Activation of the apparatus  30  will result in rotation of the auger assembly  38  within the hopper  42  and initiation of a cooling cycle. Cooling is provided by the chiller assembly  40 . As an external surface  46  of the chiller assembly  44  begins to cool, the temperature of the beverage solution is decreased. The auger  38  revolves to mix the beverage solution within the hopper  42 . The auger assembly  38  includes a helically configured blade which is positioned in close proximity to the external surface  46  of the chiller assembly  40 . As the beverage solution is cooled, ice crystals form in the solution. As the ice crystals form, generally on or near the surface  46  of the chiller assembly  40 , the auger assembly  38  removes these crystals from the surface  46 . When a desired beverage consistency is attained, beverage may be dispensed through a dispensing nozzle  48  into a container  50  positioned therebelow. 
     Having now briefly described the general structure and operation of the present invention, we now turn a more detailed discussion of the various structures of the apparatus  30 . More particularly, we turn now to FIG. 8 which shows a motor shaft assembly  52 . With further reference to FIGS. 12-15, the motor shaft assembly  52  is connected to the drive motor  36 . Operation of the motor  36  rotates the motor shaft assembly  52  attached thereto and correspondingly rotates the auger assembly  38  attached to a distal end  54  of the motor shaft assembly  52 . The motor shaft assembly  52  defines an axis of rotation. It should be noted, that in the present invention, the motor shaft assembly  52  extends through a hollow bore  56  within the chiller assembly  40 . When the drive motor  36  is operated, the rotation of the motor shaft assembly  52 , driving the auger assembly  38  causes movement of the beverage solution through the hopper  42 . 
     An enlarged, exploded view of the motor shaft assembly  52  is shown in FIG.  12 . As shown in FIG. 12, a pair of torsion springs  60  are positioned within a torsion spring retainer  62 . As shown in FIG. 14, a first end  64  of the torsion springs  60  is retained on an auger shaft  66 . A second end  68  of the torsion springs  60  is retained on a motor shaft  70 . A central portion  72  of the torsion springs are housed within the torsion spring retainer body  62 . The ends  64 ,  68  are positioned in torsion spring bearings  74 ,  76 , respectively retained on the auger shaft  66  and the motor shaft  70 . 
     The assembly  52  is retained as shown in FIG. 14 by use of a first pin  78  extending through the retainer  62 , auger shaft  66 , bearings  74  and torsion springs  60 . A second pin  80  extends through a slot  82  in the retainer  62  in a corresponding slot  84  in the second end  68  of the torsion springs  60 . The slot in the torsion spring  60  allows the assembly  52  to be easily removed from and attached to the drive motor  36 . With further reference to FIG. 15, it can be seen that the slot  82  in the retainer allows for a degree of angular movement or rotation of the retainer  62  relative to the motor shaft  70 . A reference pin  88  is provided on the retainer  62  so that the relative angular movement of the pins  80 ,  88  can be sensed by a torque sensor  244  positioned in close proximity thereto. Sensing of the angular movement of these pins  80 ,  88  is used in controlling solenoid valves  212 ,  214  and the compressor  202  while the drive motor  36  operates. Sensing the angular movement is achieved by measuring the elapsed time between pins  80 ,  88  and combining it with the elapsed time for a complete revolution to arrive at a percent of revolution value for the spacing between pins  80 ,  88 . This method compensates for variations in motor speed due to manufacturing tolerances and instantaneous load variations which have a slight effect on motor speed. 
     As further shown in the schematic diagram of FIG.  33  and in the partial fragmentary view of FIGS. 14,  15  and  15 A, an electronic sensor assembly or sensor  244  monitors the torque as the result of the rotation or twisting motion sensed by movement of the displacement of the pins  80 ,  88 . The slot  82  provides a space for relative, yet limited, motion of the retainer  62  relative to the drive shaft  70 . The torsion springs  60  provide a degree of resistance to the twisting motion. The sensor assembly  244  includes a printed circuit board  245  to which is attached a pair of sensors  247 ,  249 . The pins  80 ,  88  rotate through a rotational path  251  between the sensors  247 ,  249  breaking a beam path  253  therebetween. The circuit board  245  of the assembly  244  is connected to a controller  238  via line  253 . A degree of deflection  255  occurs and can be observed between the pins  80 ,  88 . It should be noted that the sensor  244  as described herein is a single sensor which is used on either the left or right side. As shown in the schematic diagram of FIG. 33, two torque sensors, a left and a right torque sensor are provided. Additional torque sensors may be provided for additional hoppers, if needed. 
     Twisting is measured by checking the elapsed time between rotations of the reference pin  88  relative to the second pin  80 . The elapsed time sensed between the pins  80 ,  88  approximate an angular deflection  255 . When a predetermined amount of angular deflection is sensed, the compressor  202  is deactivated thereby preventing further chilling, yet rotation of the auger  38  is maintained so as to maintain consistency of the beverage mixture. In this way, the present invention senses the torque on the motor shaft assembly  52  without imposing additional wear and tear on the drive motor  36 . This greatly enhances the life and reliability of the drive motor  36 , provides greater accuracy in controlling the cooling cycle, and provides for greater control and adjustment in sensing these conditions. 
     Advantageously, the beverage apparatus  30  of the present invention is adapted to compensate for abnormalities or errors in the torque sensors  247 ,  249  or drive motor  36 . In particular, the controller  238  (FIG. 33) of the beverage apparatus  30  is adapted to detect an abnormality in the torque sensors  247 ,  249  or drive motor  36 . If an abnormality is detected, the controller  238  will automatically activate the compressor  202  to maintain the beverage mixture at a predetermined temperature, for example, 35° F. In this manner, the beverage mixture will be protected from spoiling even if the torque sensors  247 ,  249  fail or the drive motor  36  stops. 
     Turning now to the auger assembly  38  which is driven by the drive motor  36  and the motor shaft assembly  52 , the auger assembly  38  as shown includes three auger sections  90 . One of the auger sections  90  is shown in FIGS. 18-20. Three identical auger sections  90  are connected by interlocking structures  91  on opposite ends thereof. As shown in FIG. 19, an interlocking recess  92  is provided on one end of the auger section  90  while an interlocking protrusion  94  is provided on the opposite end of the auger section  90 . By connecting the interlocking portions  92 ,  94 , the auger sections  90  can be coupled to create the larger continuous helical blade of the auger assembly  38 . 
     These auger sections  90  are retained in engagement by auger latch bars  96 ,  98  which have clips  100  for engagement with necked areas  102  on the auger sections  90 . The clips are attached to and spaced apart by cross members  104 . As shown in FIGS. 21-24, the clips  100  are configured with a reduced dimension mouth  106  to provide snap-fit engagement over the necked areas  102 . The necked areas  102  are also provided in the area where the interlocking structures  92 ,  94  are mated. As such, the clips  100  also assure that the interlocking structures  91  will not become disengaged during rotation of the auger  38 . The cross members  104  also provide desired spacing between the sections  90  to prevent shifting of the auger sections  90  during rotation. It should be noted that the auger latch bar  96  includes four clips which attach to a first  110  and a second  112  terminal end of the three attached auger sections  90 . A cross member  114  positioned near the first terminal end  110  is oriented generally perpendicular to the other cross members  104 . The perpendicular cross member  114  provides a driving action on the beverage solution positioned towards the base  116  of the chiller assembly  40 . 
     The second terminal end  112  positioned towards the front of the apparatus  30  includes an auger nose  120  attached thereto. The auger nose  120  includes a sweeping blade  122 . A cap end  124  of the auger nose  120  attaches to the distal end  54  of the motor shaft assembly  52 . As such, connection of the cap end  124  to the motor shaft assembly  52  results in rotation of the auger assembly  38 . Generally, driving forces are transferred from the motor shaft  52  to the auger nose  120 . The series of auger sections  90  attached to the auger nose  120  are pulled or rotated around the outside  46  of the chiller assembly  40 . This driving and sweeping action pull the beverage mixture from the rear of the hopper  42  towards the front of the hopper  42 . 
     Mixture which is pulled from the rear of the hopper  42  is pulled downwardly into the auger path and mixture which is pushed from the front of the hopper  42  is pushed upwardly over the auger  38 . As the result of pulling and pushing of the beverage mixture, a churning hump  130  (see, FIG. 4) tends to form in a middle portion of the hopper  42 . When a hopper is filled with beverage solution, the hump tends to rise towards the cover assembly. In this regard, the cover assembly  44  includes the cover  132  having a cover liner  134  retained therein. In the present invention, the cover liner  134  is provided with a concave recessed area  136 . As can be seen in FIGS. 25-27, in the recessed area  136  the concave portion faces the inside of the hopper  42  to accommodate the churning hump  130  positioned thereunder. As a result, the churning hump  130  does not touch the inside surface of the cover liner  134  thereby eliminating additional cleaning problems which are encountered with the prior art devices. 
     With further reference to FIGS. 25-27, the hopper cover  132  includes a mounting channel  138  having a central opening  140  therein. A flange rail  142  formed on an upper edge  144  of the hopper  42  is received in the central opening  140 . Centering ribs  146  are provided on either end of the cover liner  134 . As noted above, the cover liner  134  is retained in the hopper cover  132  with the flange rail  142  received in the central opening  140  of the hopper cover assembly  44 , the centering ribs  146  rest against inside surfaces  148  of the hopper  42  thereby centering the hopper cover assembly  44  on the upper edge  144 . The hopper cover assembly  44  can be removed by lifting it off of the hopper  42 . 
     Alternatively, it may be desirable only to slightly displace the hopper cover assembly  44  and not necessarily completely remove the assembly  44 . As such, the present invention allows the hopper cover assembly  44  to be slidably displaced parallel to the flange rails  142 . A slight force applied to either end of the hopper cover assembly  44  sufficient to overcome the interference created by the centering rib  146  against the inside surface  148  of the wall will result in the cover assembly  44  slidably moving. Slidable movement is achieved with the mounting channel  138  being retained on and sliding along the flange rail  142 . The present invention allows the hopper cover assembly  144  to be displaced in either direction along the upper edge  144  of the hopper  42  generally parallel to the flange rails  142 . This allows an operator to access the hopper  42  from either end, for example, to add additional beverage solution. 
     With further reference to FIG. 6, a drip tray assembly  150  is attached to a front portion of the chassis  152 . A pair of tray arms  154  extend from the chassis  152 . The drip tray assembly  150  includes a server drip pan  156  and a drip tray cover  158  positioned over the pan  156 . The pan  156  is formed with a pair of spaced apart slots  160  formed therein for receiving the tray arms  154 . A pair of magnets  162  are attached to the chassis  152 . The magnets  162  are positioned for attraction to metal plate  164  attached to the drip pan  156 . Alternatively, the drip pan  156  may be formed of a metal material instead of plastic as in the preferred embodiment thereby eliminating the need for metal plates  164  thereon. 
     In use, the drip pan  156  with the cover  158  thereon and having a grate  166  retained in the cover  158  can be attached to and removed from the chassis  152  without complication. To remove the drip tray assembly  150 , the pan and cover  156 ,  158  are grasped and removed from the chassis  152 . A nominal force is applied to the drip tray assembly  150  to overcome the attractive forces between the magnets  162  and the corresponding metal plates  164 . The pan  156  is moved in order to disengage the slots  160  from the corresponding tray arms  154 . Once removed from the chassis  152 , the drip tray assembly  150  can be disassembled, cleaned, and returned to service. When returned to service, the slots  160  are positioned over the corresponding arms  154  and slid into position in order to engage the metal plate  164  with the corresponding magnet  162 . The magnet and metal plate  162 ,  164  retain the assembly  150  in place. 
     A hopper drip tray  170  is provided underneath the hopper  42 . The hopper drip trays  170  collect condensation which forms on, and runs off of, the outside surface of the hoppers  42 . A drain hole  172  is provided in each tray  170  which communicates with a drain tube  174  retained relative to the chassis  152  by a clip  176 . Condensate from the hoppers  42  drain into the drip tray assembly  150  for evaporation or disposal in due course. 
     A control panel drawer  180  is provided in the front panel  182  of the housing  34 . With reference to FIGS. 28-31, the control panel drawer  180  includes a drawer frame  184  in which is retained a control panel  186  and control devices  188 . The control panel drawer  180  allows the controls to be completely removed from the serving area, thus avoiding splashing or the accumulation of beverage substance thereon. It is particularly helpful when considering that many of the beverage substances include sugar components and therefore can be quite sticky and easily damage control devices. Additionally, the orientation of the control devices  188  on the control panel  186  within the drawer  184  allow the control devices  188  to be sufficiently large to facilitate ease of use of the controls. Additionally, a lock device  190  is provided on the drawer  184  in order to prevent unauthorized access to the controls. A drawer stop  192  is provided on a bottom portion of the drawer  180  to allow the drawer  180  to be fully extracted from the housing  34  while retaining it in engagement therewith. 
     Turning now to FIGS. 9-11 and  32 , the coolant system  200  of the present invention is shown diagrammatically in FIG. 32 while specific structures of the coolant system  200  are shown in FIGS. 9-11. The coolant system  200  includes a compressor  202 , a condenser  204 , a filter dryer  206  and a suction accumulator  208 . As shown in FIG. 32, the coolant system  200  provides coolant distribution to a pair of chiller assemblies  40 ,  41 . Coolant is distributed to both or only one of the chiller assemblies  40 ,  41 . Selective control of coolant to the chiller assemblies  40 ,  41  is achieved by using a splitter  210  and a pair of controllable solenoid valves  212 ,  214 . 
     With further reference to FIGS. 9-11, the chiller assembly  40  includes a cooling drum  216  having a wall  218  and defining a cavity  220  therein. The cooling drum  216  is formed of a thermally conductive material to help transfer heat from the mixture which surrounds the outside surface  46  of the drum  216  to a refrigeration coil  222  retained in the cavity  220 . The coil  222  is sized and dimensioned to snugly fit against the inside surface of the wall  218  to facilitate heat transfer from the beverage solution to the refrigeration or coolant medium flowing through the coil  222 . As shown in FIG. 11, epoxy  224  is applied to the coil  222  to fill the spaces between neighboring portions of the coil  222 . The epoxy  224  is chosen for its thermally conductive characteristic so as to further increase the thermal conductivity between the drum  216 , the coil  222  and the coolant medium flowing through the coil  222 . Generally, the epoxy  224  is applied to the outside of the coil  222  and to the inside surface of the drum  216  before inserting the coil  222  into the cavity  220  of the drum  216 . The epoxy  224  is applied to fill the small voids between the curved surfaces of the coil  222  thereby facilitating increased heat transfer therethrough. With reference to FIG. 9, insulation material  226  is provided internally of the coil  222  to insulate the area between the coil  222  and the hollow bore  56  through which the shaft assembly  52  is positioned. As indicated in FIG. 32, the auger assembly  38  moves relative to the fixed drum  216  so as to spread and move beverage mixture along the outside surface  46  thereby transferring heat from the beverage mixture to the coolant flowing through coil  222 . A thermistor temperature sensor  230  is provided internally of the chiller assembly  40  and is connected to the control circuit  238  as indicated in FIG.  33 . 
     Turning now to the electrical schematic as shown in FIG. 33, the present system includes generally redundant left and right assemblies. As such, reference to each assembly will be made by using identical reference numerals where possible. Further, reference numerals indicated hereinabove will generally be used to indicate the same elements illustrated diagrammatically in the schematic of FIG.  33 . 
     With reference to FIG.  33  and additional reference to FIG. 28, the system includes a main power switch  232  which controls power to the overall system. Additionally, each hopper  42  and chiller assembly  40  have a separate auger switch  234  which controls the power to the corresponding drive motor  36 . Control of the chilling of beverage is achieved by use of the ice/no-ice switches  236  which are coupled to the control circuit or controller  238 . 
     The action of solenoid valves  212 ,  214  is controlled by controller  238 . In the “ice” position of  236 , the valves  212 ,  214  are controlled in response to the torque measurement from sensor  244 . In the “no-ice” position, the valves  212 ,  214  are controlled in response to the temperature sensed by thermistor  230  as compared to a desired value (typically 37° F.) stored in the memory of the controller  238 . 
     Variable resistors  240  allow the user to set the torque which yields the desired slush stiffness when switch  236  is in the “ice” position. 
     The compressor  202  is switched on or off by the controller  238  in a way which maximizes its life by reducing wear and tear. Competitive machines do not have feature 2 below. 
     1. When the controller  238  calls for more cooling and the compressor  202  is off, the controller  238  turns on valves  212 ,  214  for a predetermined time (about 2 minutes) prior to turning on the compressor  202 . This allows any trapped pressure in the coolant system  200  to equalize. The compressor  202  can be damaged by starting when there is a large pressure difference from output to input. 
     2. When no further cooling is needed, the controller  238  turns off valves  212 ,  214  and allows the compressor  202  to continue to run for approximately one minute. This allows for a momentary high torque indication from sensor  244  which prematurely indicated the slush has reached the desired consistency. This could be caused by a chunk of ice jammed in the auger  38  or stuck to the drum  216 . If cooling is called for within the one minute window, then only the valves  212 ,  214  need be turned on and the compressor  202  is not cycled off and back on. Note, an additional benefit of this technique is the compressor  202  does not have to go through the 2 minute wait period (described above in 1) and cool down time is shortened. 
     Alternatively, in the preferred embodiment of the present invention, the controller  238  energizes valves  212 ,  214  any time the pressure in the cooling system  200  needs to be equalized. For example, when the main power to the beverage apparatus  30  is turned on, the pressure in the cooling system  200  will need to be equalized. Thus, in the preferred embodiment, when the beverage apparatus  30  is turned on, the controller  238  will activate the valves  212 ,  214  for a predetermined time to allow the pressure in the cooling system  200  to equalize and then turn off the valves  212 ,  214 . For example, the controller  238  could activate the valves  212 ,  214  for three minutes. Since equalization of the cooling system  200  will have already been completed, any time later when cooling is required, the compressor  202  can be energized simultaneously with the valves  212 ,  214 . Thus, cooling can begin immediately and the efficiency of the cooling operation is increased. 
     Similarly, the controller  238  will equalize the system pressure at the end of a cooling cycle, so that the cooling can begin again immediately, any time cooling is necessary subsequent to the equalization process. In particular, at the end of a cooling cycle, the controller  238  will turn the compressor  202  off and then wait a predetermined time, e.g. 5 seconds. After the predetermined time has elapsed, the controller  238  will activate the valves  212 ,  214  for a preselected time period and then turn the valves  212 ,  214  off. Preferably, the valves  212 ,  214  are energized for 3 minutes before being turned off. 
     Further, with regard to the temperature of the beverage, a night control  242  is provided to place the apparatus  30  in a “night” mode. The night control  242  overrides the pre-existing control pre-sets to maintain the beverage at a predetermined temperature point above freezing yet in a chilled condition. The night control  242  effectively overrides the settings of the “ice/no-ice” switches  236  and places both in the “no-ice” condition. The night control  242  allows the mixture to thaw from a slush state to a liquid state. This periodic thawing during off hours or “night” hours helps maintain consistent flavor in the mixture. If the mixture were to be maintained in a frozen condition continuously without ever going back to a liquid solution, the flavor solids in the mixture would tend to migrate the outside of the crystals retained in the slush. In other words, each crystal tends to form with the flavor solids mixed throughout. As the mixture is maintained in a slush state over a long period of time, the solids tend to migrate from the center of the crystal to the outside. This decreases the desired characteristics of the flavor and reduces consistency in the beverage. As such, the night control  242  helps maintain consistency and flavor quality throughout service hours. 
     Additionally, the night control  242  is set to maintain the mixture in a chilled state. The chilled state helps to reduce and minimize the start up time. In other words, for example, if the beverage mixture is maintained at 36° degrees during off hours and the desired slush temperature is 33°, the mixture only needs to be decreased by 3° in order to achieve the desired dispensing temperature. Whereas if the mixture is allowed to completely thaw and rise to room temperature, for example 70°, the temperature would need to be decreased 37° to achieve serving temperature. As such, it can be seen that the control of the present invention by use of the night control  242  and method facilitate more efficient operation of the beverage system. 
     A left and right torque sensor  244  are provided to sense the pins  80 ,  88 . As such, the compressor  202  can be controlled as a result of the torque sensor  244 . 
     A lamp assembly  248  is provided in the cover assembly  44 . The lamp illuminates display panels  250  attached to the cover  132 . Each lamp assembly  248  associated with each hopper assembly  32  is coupled to the control circuit  238  by way of a removable connector  252 . The removable connector  252  allows the cover assembly  44  to be completely removed from the hopper assembly  32  and from the overall apparatus  30 . 
     While a preferred embodiment of the present invention is shown and described, it is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the spirit and scope of the claims. The invention is not intended to be limited by the foregoing disclosure.