Patent Publication Number: US-11649999-B2

Title: Direct cooling ice maker with cooling system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     FIELD OF THE INVENTION 
     This application relates generally to an ice maker for a refrigeration appliance, and more particularly, to a refrigeration appliance including a direct cooling ice maker and a cooling system for the same. 
     BACKGROUND OF THE INVENTION 
     Conventional refrigeration appliances, such as domestic refrigerators, typically have both a fresh food compartment and a freezer compartment or section. The fresh food compartment is where food items such as fruits, vegetables, and beverages are stored and the freezer compartment is where food items that are to be kept in a frozen condition are stored. The refrigerators are provided with a refrigeration system that maintains the fresh food compartment at temperatures above 0° C., such as between 0.25° C. and 4.5° C. and the freezer compartments at temperatures below 0° C., such as between 0° C. and −20° C. 
     The arrangements of the fresh food and freezer compartments with respect to one another in such refrigerators vary. For example, in some cases, the freezer compartment is located above the fresh food compartment and in other cases the freezer compartment is located below the fresh food compartment. Additionally, many modern refrigerators have their freezer compartments and fresh food compartments arranged in a side-by-side relationship. Whatever arrangement of the freezer compartment and the fresh food compartment is employed, typically, separate access doors are provided for the compartments so that either compartment may be accessed without exposing the other compartment to the ambient air. 
     Such conventional refrigerators are often provided with a unit for making ice pieces, commonly referred to as “ice cubes” despite the non-cubical shape of many such ice pieces. These ice making units normally are located in the freezer compartments of the refrigerators and manufacture ice by convection, i.e., by circulating cold air over water in an ice tray to freeze the water into ice cubes. Storage bins for storing the frozen ice pieces are also often provided adjacent to the ice making units. The ice pieces can be dispensed from the storage bins through a dispensing port in the door that closes the freezer to the ambient air. The dispensing of the ice usually occurs by means of an ice delivery mechanism that extends between the storage bin and the dispensing port in the freezer compartment door. 
     However, for refrigerators such as the so-called “bottom mount” refrigerator, which includes a freezer compartment disposed vertically beneath a fresh food compartment, placing the ice maker within the freezer compartment is impractical. Users would be required to retrieve frozen ice pieces from a location close to the floor on which the refrigerator is resting. And providing an ice dispenser located at a convenient height, such as on an access door to the fresh food compartment, would require an elaborate conveyor system to transport frozen ice pieces from the freezer compartment to the dispenser on the access door to the fresh food compartment. Thus, ice makers are commonly included in the fresh food compartment of bottom mount refrigerators, which creates many challenges in making and storing ice within a compartment that is typically maintained above the freezing temperature of water. 
     There is provided a cooling system for an ice maker including an evaporator coil in direct contact with an ice tray of the ice maker for cooling the ice tray. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with one aspect, there is provided a refrigeration appliance including a fresh food compartment for storing food items in a refrigerated environment having a target temperature above 0° C., a freezer compartment for storing food items in a sub-freezing environment having a target temperature below 0° C., an ice maker disposed within the fresh food compartment for freezing water into ice pieces, and a valve. The ice maker includes an ice mold with an upper surface comprising a plurality of cavities formed therein for the ice pieces. An ice maker evaporator cools the ice mold to a temperature below 0° C. via thermal conduction. The ice maker includes a cooling system having a fresh food evaporator, an ice box evaporator tube and a freezer evaporator all disposed in series with the ice maker evaporator. A valve includes an inlet, a first outlet connected to an inlet of the fresh food evaporator, a second outlet connected to a first bypass line around the fresh food evaporator, and a third outlet connected to a second bypass line around the fresh food evaporator and the ice maker evaporator. The inlet of the valve is connected to the first outlet of the valve when the valve is in a first position such that a refrigerant flows through the fresh food evaporator, the ice maker evaporator, the ice box evaporator tube and the freezer evaporator, in that order. The inlet of the valve is connected to the second outlet of the valve when the valve is in a second position such that the refrigerant flows through the first bypass line, the ice maker evaporator, the ice box evaporator tube and the freezer evaporator, in that order. The inlet of the valve is connected to the third outlet of the valve when the valve is in a third position such that the refrigerant flows through the second bypass line, the ice box evaporator tube and the freezer evaporator, in that order. 
     In the refrigeration appliance, the ice maker evaporator abutting at least one lateral side surface of the ice mold. 
     In the refrigeration appliance, the first bypass line connects to a line connecting the fresh food evaporator to the ice maker evaporator at a location upstream of the ice maker evaporator. 
     In the refrigeration appliance, the second bypass line connects to a line connecting the ice maker evaporator to the ice box evaporator tube at a location upstream of the ice box evaporator tube. 
     In the refrigeration appliance, the valve is a stepper valve. 
     In accordance with another aspect, there is provided a refrigeration appliance including a fresh food compartment for storing food items in a refrigerated environment having a target temperature above 0° C., a freezer compartment for storing food items in a sub-freezing environment having a target temperature below 0° C., an ice maker disposed within the fresh food compartment for freezing water into ice pieces, and a valve. The ice maker includes an ice mold comprising at least one cavity formed therein for making the ice pieces. An ice maker evaporator cools the ice mold to a temperature below 0° C. via thermal conduction. The ice maker includes a cooling system having a fresh food evaporator. An ice box evaporator tube and a freezer evaporator both are disposed in series with the ice maker evaporator. A valve includes an inlet, a first outlet connected to an inlet of the fresh food evaporator, a second outlet connected to an inlet of the ice maker evaporator, and a third outlet connected to a bypass line around the fresh food evaporator and the ice maker evaporator. The inlet of the valve is connected to the first outlet of the valve when the valve is in a first position such that a refrigerant flows through the fresh food evaporator, the ice box evaporator tube and the freezer evaporator, in that order. The inlet of the valve is connected to the second outlet of the valve when the valve is in a second position such that the refrigerant flows through the ice maker evaporator, the ice box evaporator tube and the freezer evaporator, in that order. The inlet of the valve is connected to the third outlet of the valve when the valve is in a third position such that the refrigerant flows through the bypass line, the ice box evaporator tube and the freezer evaporator, in that order. 
     In the refrigeration appliance, the ice maker evaporator abutting at least one lateral side surface of the ice mold. 
     In the refrigeration appliance, the bypass line connects to a line connecting the ice maker evaporator to the ice box evaporator tube at a location upstream of the ice box evaporator tube. 
     In the refrigeration appliance, when the valve is in the first position the fresh food evaporator fluidly communicates with a line connecting the ice maker evaporator to the ice box evaporator tube at a location upstream of the ice box evaporator tube. 
     In the refrigeration appliance, the valve is a stepper valve. 
     In accordance with yet another aspect, there is provided a cooling system for a refrigeration appliance. The cooling system includes a first evaporator for cooling water to a temperature below 0° C. via thermal conduction, a second evaporator, a third evaporator and a fourth evaporator both disposed in series with the first evaporator, and a valve. The valve includes an inlet, a first outlet connected to an inlet of the second evaporator, a second outlet fluidly connected to an inlet of the first evaporator; and a third outlet connected to a bypass line around the first evaporator and the second evaporator. The inlet of the valve is connected to the first outlet of the valve when the valve is in a first position such that a refrigerant flows through the second evaporator, the third evaporator and the fourth evaporator, in that order. The inlet of the valve is connected to the second outlet of the valve when the valve is in a second position such that the refrigerant flows through the first evaporator, the third evaporator and the fourth evaporator, in that order, but not through the second evaporator. The inlet of the valve is connected to the third outlet of the valve when the valve is in a third position such that the refrigerant flows through the bypass line, the third evaporator and the fourth evaporator, in that order, but not through the first evaporator and the second evaporator. 
     In the cooling system, the first evaporator is an ice maker evaporator. 
     In the cooling system, the second evaporator is a fresh food evaporator for a fresh food compartment. The fresh food compartment stores food items in a refrigerated environment having a target temperature above 0° C. 
     In the cooling system, the third evaporator is an ice box evaporator tube. 
     In the cooling system, the fourth evaporator is a freezer evaporator for a freezer compartment, the freezer compartment for storing food items in a sub-freezing environment having a target temperature below 0° C. 
     In the cooling system, the valve is a stepper valve. 
     In the cooling system, the second evaporator is in series with the first evaporator, the third evaporator and the fourth evaporator. 
     In the cooling system, the second outlet of the valve is connected to a refrigerant line that bypasses the second evaporator. 
     In the foregoing cooling system, the first evaporator is disposed in the refrigerant line. 
     In the foregoing cooling system, the refrigerant line connects to a second refrigerant line that connects an outlet of the second evaporator to an inlet of the first evaporator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front perspective view of a household French Door Bottom Mount showing doors of the refrigerator in a closed position; 
         FIG.  2    is a front perspective view of the refrigerator of  FIG.  1    showing the doors in an open position and an ice maker in a fresh food compartment; 
         FIG.  3    is a side perspective view of an ice maker with a side wall of a frame of the ice maker removed for clarity; 
         FIG.  4 A  is a side perspective view of a first embodiment an ice tray assembly for the ice maker of  FIG.  3   ; 
         FIG.  4 B  is a bottom perspective view of the ice tray assembly of  FIG.  4 A ; 
         FIG.  5    is a section view of the ice tray assembly of  FIG.  4 A  taken along line  5 - 5 ; 
         FIG.  6    is a side perspective view of an ice maker evaporator for the ice tray assembly of  FIG.  4   ; 
         FIG.  7    is a side perspective view of the ice maker evaporator of  FIG.  6    and an ice box evaporator assembly illustrating an example flow path of a refrigerant through the ice maker evaporator and the ice box evaporator assembly; 
         FIG.  8    is a schematic of a cooling system for the refrigerator of  FIG.  1   ; 
         FIG.  9    is a schematic of a second embodiment cooling system for the refrigerator of  FIG.  1   ; and 
         FIG.  10    is a side section view taken along line  10 - 10  of  FIG.  3   ; and 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Referring now to the drawings,  FIG.  1    shows a refrigeration appliance in the form of a domestic refrigerator, indicated generally at  20 . Although the detailed description that follows concerns a domestic refrigerator  20 , the invention can be embodied by refrigeration appliances other than with a domestic refrigerator  20 . Further, an embodiment is described in detail below, and shown in the figures as a bottom-mount configuration of a refrigerator  20 , including a fresh food compartment  24  disposed vertically above a freezer compartment  22 . However, the refrigerator  20  can have any desired configuration including at least a fresh food compartment  24  and an ice maker  50  ( FIG.  2   ), such as a top mount refrigerator (freezer disposed above the fresh food compartment), a side-by-side refrigerator (fresh food compartment is laterally next to the freezer compartment), a standalone refrigerator or freezer, etc. 
     One or more doors  26  shown in  FIG.  1    are pivotally coupled to a cabinet  29  of the refrigerator  20  to restrict and grant access to the fresh food compartment  24 . The door  26  can include a single door that spans the entire lateral distance across the entrance to the fresh food compartment  24 , or can include a pair of French-type doors  26  as shown in  FIG.  1    that collectively span the entire lateral distance of the entrance to the fresh food compartment  24  to enclose the fresh food compartment  24 . For the latter configuration, a center flip mullion  31  ( FIG.  2   ) is pivotally coupled to at least one of the doors  26  to establish a surface against which a seal provided to the other one of the doors  26  can seal the entrance to the fresh food compartment  24  at a location between opposing side surfaces  27  ( FIG.  2   ) of the doors  26 . The mullion  31  can be pivotally coupled to the door  26  to pivot between a first orientation that is substantially parallel to a planar surface of the door  26  when the door  26  is closed, and a different orientation when the door  26  is opened. The externally-exposed surface of the center mullion  31  is substantially parallel to the door  26  when the center mullion  31  is in the first orientation, and forms an angle other than parallel relative to the door  26  when the center mullion  31  is in the second orientation. The seal and the externally-exposed surface of the mullion  31  cooperate approximately midway between the lateral sides of the fresh food compartment  24 . 
     A dispenser  28  ( FIG.  1   ) for dispensing at least ice pieces, and optionally water, can be provided on an exterior of one of the doors  26  that restricts access to the fresh food compartment  24 . The dispenser  28  includes a lever, switch, proximity sensor or other device that a user can interact with to cause frozen ice pieces to be dispensed from an ice bin  54  ( FIG.  2   ) of the ice maker  50  disposed within the fresh food compartment  24 . Ice pieces from the ice bin  54  can exit the ice bin  54  through an aperture  62  and be delivered to the dispenser  28  via an ice chute  32  ( FIG.  2   ), which extends at least partially through the door  26  between the dispenser  28  and the ice bin  54 . 
     Referring to  FIG.  1   , the freezer compartment  22  is arranged vertically beneath the fresh food compartment  24 . A drawer assembly (not shown) including one or more freezer baskets (not shown) can be withdrawn from the freezer compartment  22  to grant a user access to food items stored in the freezer compartment  22 . The drawer assembly can be coupled to a freezer door  21  that includes a handle  25 . When a user grasps the handle  25  and pulls the freezer door  21  open, at least one or more of the freezer baskets is caused to be at least partially withdrawn from the freezer compartment  22 . 
     The freezer compartment  22  is used to freeze and/or maintain articles of food stored in the freezer compartment  22  in a frozen condition. For this purpose, the freezer compartment  22  is in thermal communication with a freezer evaporator  302  ( FIGS.  8  and  9   ) that removes thermal energy from the freezer compartment  22  to maintain the temperature therein at a temperature of 0° C. or less during operation of the refrigerator  20 , preferably between 0° C. and −50° C., more preferably between 0° C. and −30° C. and even more preferably between 0° C. and −20° C. 
     The refrigerator  20  includes an interior liner  34  ( FIG.  2   ) that defines the fresh food compartment  24 . The fresh food compartment  24  is located in the upper portion of the refrigerator  20  in this example and serves to minimize spoiling of articles of food stored therein. The fresh food compartment  24  accomplishes this by maintaining the temperature in the fresh food compartment  24  at a cool temperature that is typically above 0° C., so as not to freeze the articles of food in the fresh food compartment  24 . It is contemplated that the cool temperature preferably is between 0° C. and 10° C., more preferably between 0° C. and 5° C. and even more preferably between 0.25° C. and 4.5° C. According to some embodiments, cool air from which thermal energy has been removed by the freezer evaporator  302  can also be blown into the fresh food compartment  24  to maintain the temperature therein greater than 0° C. preferably between 0° C. and 10° C., more preferably between 0° C. and 5° C. and even more preferably between 0.25° C. and 4.5° C. For alternate embodiments, a separate fresh food evaporator (not shown) can optionally be dedicated to separately maintaining the temperature within the fresh food compartment  24  independent of the freezer compartment  22 . According to an embodiment, the temperature in the fresh food compartment  24  can be maintained at a cool temperature within a close tolerance of a range between 0° C. and 4.5° C., including any subranges and any individual temperatures falling with that range. For example, other embodiments can optionally maintain the cool temperature within the fresh food compartment  24  within a reasonably close tolerance of a temperature between 0.25° C. and 4° C. 
     An illustrative embodiment of the ice maker  50  is shown in  FIG.  3   . In general, the ice maker  50  includes a frame  52 , an ice bin  54 , an ice tray assembly  100  and an air handler assembly  70 . The ice bin  54  stores ice pieces made by the ice tray assembly  100  and the air handler assembly  70  circulates cooled air to the ice tray assembly  100  and the ice bin  54 . The ice maker  50  is secured within the fresh food compartment  24  using any suitable fastener. The frame  52  is generally rectangular-in-shape for receiving the ice bin  54 . The frame  52  includes insulated walls for thermally isolating the ice maker  50  from the fresh food compartment  24 . A plurality of fasteners (not shown) may be used for securing the frame  52  of the ice maker  50  within the fresh food compartment  24  of the refrigerator  20 . 
     For clarity the ice maker  50  is shown with a side wall of the frame  52  removed; normally, the ice maker  50  would be enclosed by insulated walls. The ice bin  54  includes a housing  56  having an open, front end and an open top. A front cover  58  is secured to the front end of the housing  56  to enclose the front end of the housing  56 . When secured together to form the ice bin  54 , the housing  56  and the front cover  58  define an internal cavity  54   a  of the ice bin  54  used to store the ice pieces made by the ice tray assembly  100 . The front cover  58  may be secured to the housing  56  by mechanical fasteners that can be removed using a suitable tool, examples of which include screws, nuts and bolts, or any suitable friction fitting possibly including a system of tabs allowing removal of the front cover  58  from the housing  56  by hand and without tools. Alternatively, the front cover  58  is non-removably secured in place on the housing  56  using methods such as, but not limited to, adhesives, welding, non-removable fasteners, etc. In various other examples, a recess  59  is formed in a side of the front cover  58  to define a handle that may be used by a user for ease in removing the ice bin  54  from the ice maker  50 . An aperture  62  is formed in a bottom of the front cover  58 . A rotatable auger (not shown) can extend along a length of the ice bin  54 . As the auger rotates, ice pieces in the ice bin  54  are urged ice towards the aperture  62  wherein an ice crusher (not shown) is disposed. The ice crusher is provided for crushing the ice pieces conveyed thereto, when a user requests crushed ice. The augur can optionally be automatically activated and rotated by an auger motor assembly (not shown) of the air handler assembly  70 . The aperture  62  is aligned with the ice chute  32  ( FIG.  2   ) when the door  26  is closed. This alignment allows for the auger to push the frozen ice pieces stored in the ice bin  54  into the ice chute  32  to be dispensed by the dispenser  28 . 
     Referring to  FIGS.  4 A and  4 B , the ice tray assembly  100  includes an ice mold  102 , a cover  118 , a harvest heater  126  ( FIGS.  4 B and  5   ) for partially melting the ice pieces, a plurality of sweeper-arms  132  ( FIG.  5   ) and an ice maker evaporator  150 . The ice mold  102  is preferably made from a thermally conductive metal, like aluminum or steel. It is also preferred that the ice mold  102  is a single monolithic body. 
     The ice mold  102  includes at least one cavity  112  where water is frozen into ice, and the cavity  112  can be positioned variously depending upon the configuration of the ice mold. Referring to the example shown in  FIG.  5   , the ice mold  102  includes a top surface  104 , a bottom surface  106  and lateral side surfaces  108 . At least one cavity  112  is formed in the top surface  104  of the ice mold  102  where water is frozen into ice. In the shown embodiment, the ice mold  102  includes a plurality of cavities  112  that is configured for receiving water to be frozen into ice pieces. The plurality of cavities  112  may be defined by weirs  114 , and some or all of the weirs  114  have an aperture therethrough to enable water to flow among the cavities  112 . The cavities  112  can have multiple variants. Different cube shapes and sizes are possible (e.g., crescent, cubical, hemispherical, cylindrical, star, moon, company logo, a combination of shapes and sizes simultaneously, etc.) as long as the ice pieces can be removed by the plurality of sweeper-arms  132 . In the embodiment shown, the plurality of cavities  112  are aligned in a lateral direction of the ice mold  102 . 
     The bottom surface  106  of the ice mold  102  is contoured to receive the harvest heater  126 , as described in detail below. The bottom surface  106  includes a groove  106   a  that extends about a periphery of the bottom surface  106  for receiving the harvest heater  126  therein. 
     The lateral side surfaces  108  are contoured or sculpted to receive the ice maker evaporator  150 . The lateral side surfaces  108  may include elongated recesses  108   a  that closely match the outer profile of the ice maker evaporator  150 , as described in detail below. 
     Referring to  FIGS.  4 A and  5   , the cover  118  is attached to the top surface  104  of the ice mold  102  for securing the ice tray assembly  100  to the liner  34  of the fresh food compartment  24 . The ice mold  102  may also be attached to an interior of the frame  52  of the ice maker  50  if installed as a unit. The cover  118  includes tabs  118   a  for securing the ice tray assembly  100  to mating openings (not shown) in the liner  34  or in a top wall of the frame  52 . One longitudinal edge  118   b  of the cover  118  is dimensioned to be spaced from an upper edge of the ice mold  102  to define an opening  122 . The opening  122  is dimensioned to allow ice pieces to be ejected from the ice tray assembly  100 , as described in detail below. 
     Referring to  FIGS.  4 B and  5   , the harvest heater  126  is attached to the bottom surface  106  of the ice mold  102  to provide a heating effect to the ice mold  102  to thereby separate congealed ice pieces from the ice mold  102  during an ice harvesting operation. The heater  126  may be an electric resistive heater, and may be capture in the groove  106   a  formed in the bottom surface  106  of the ice mold  102 . The heater  126  is configured to be in direct or substantially direct contact with the ice mold  102  for increased conductive heat transfer. In the embodiment shown, the harvest heater  126  is a U-shape element that extends around a periphery of the bottom surface  106  and has a cylindrical outer surface. It is contemplated that the groove  106   a  may have a cylindrical contour that matches the outer cylindrical outer surface of the harvest heater  126 . In the embodiment shown, the legs of the U-shaped heater  126  extend along the lateral direction of the ice mold  102 . It is contemplated the heater  126  may have other shapes, for example, but not limited to, circular, oval, spiral, etc. so long as the heater  126  is disposed in direct or substantially direct contact with the ice mold  102 . 
     The plurality of sweeper-arms  132  are disposed in the cavities  112  formed in the top surface  104  of the ice mold  102 . The plurality of sweeper-arms  132  are elongated elements that are attached to a rotatable shaft  134 . As the shaft  134  rotates the sweeper-arms  132  move through the cavities  112  to force ice pieces in the cavities  112  out of the ice mold  102 . In the embodiment shown in  FIG.  5   , the shaft  134  extends in the lateral direction of the ice mold  102  and is rotatable in a clockwise direction such that the sweeper-arms  132  force the ice pieces into an area above the ice mold  102 . A lower surface of the cover  118  is curved to direct the ice pieces toward the opening  122  between the cover  118  and the ice mold  102 . As the sweeper-arms  132  continue to rotate, the ice pieces are then ejected from the ice tray assembly  100  into the ice bin  54  ( FIG.  3   ) positioned below the ice tray assembly  100 . 
     Prior to actuating the plurality of sweeper-arms  132 , the harvest heater  126  is energized to heat the ice mold  102  which, in turn, melts a lower surface of the ice pieces in the plurality of cavities  112 . A thin layer of liquid is formed on the lower surface of the ice pieces to aid in detaching the ice pieces from the ice mold  102 . The plurality of sweeper-arms  132  may then eject the ice pieces out of the ice mold  102 . 
     In the embodiment shown, the ice mold  102  is a monolithic body that includes an integrally formed water fill cup  136 . It is contemplated that the water fill cup  136  may be made of the same material as the ice mold  102 . In particular, it is contemplated that the ice mold  102  may be made of a metal material, e.g., aluminum or steel. The fill cup  136  includes side and bottom walls that are planar and sloped toward the cavities  112  in the ice mold  102 . As such, water injected into the fill cup  136  will flow, by gravity to the cavities  112  in the ice mold  102 . It is contemplated that the thermal energy provided by the harvest heater  126  may also be sufficient to melt frost or ice that may accumulate on the fill cup  136  during normal operation. 
     Referring to  FIG.  6   , the ice maker evaporator  150  includes a first leg  152 , a second leg  154  and a connecting portion  156 . In the embodiment shown, the first leg  152  is U-shaped and includes an upper portion  152   a  and a lower portion  152   b . Similarly, the second leg  154  is U-shaped and includes an upper portion  154   a  and a lower portion  154   b . The upper portions  152   a ,  154   a  and the lower portions  152   b ,  154   b  are illustrated in  FIG.  6    as straight elongated elements that extend along the lateral direction of the ice mold  102 . It is contemplated that these portions  152   a ,  154   a ,  152   b ,  154   b  can have other shapes, e.g., curved, wavy, tooth-shaped, stepped, etc. so long as these portions  152   a ,  154   a ,  152   b ,  154   b  are in intimate or surface-to-surface contact with the respective lateral side surfaces  108  of the ice mold  102 . In the embodiment shown, the ice maker evaporator  150  has a U-shape. It is contemplated that the ice maker evaporator  150  may have other shapes so long as the ice maker evaporator  150  is in intimate contact with the ice mold  102 . 
     The ice maker evaporator  150  includes an inlet end  162  for allowing a refrigerant to be injected into the ice maker evaporator  150  and an outlet end  164  for allowing the refrigerant to exit the ice maker evaporator  150 . A first capillary tube  332  (described in detail below) is attached to the inlet end  162 . 
     Referring to  FIG.  5   , in the embodiment shown, the ice maker evaporator  150  has a cylindrical outer surface and the respective recesses  108   a  formed in the lateral side surfaces  108  of the ice mold  102  have a matching contour. In the embodiment shown, the recesses  108   a  are contoured to preferably contact at least half or 180° of the cylindrical outer surface of the first and second legs  152 ,  154  of the ice maker evaporator  150 . It is contemplated that the amount of contact may be more or less than half or 180°. 
     Retention clips  172  are provided for applying a retaining force to the ice maker evaporator  150  for securing the ice maker evaporator  150  into both lateral side surfaces  108  of the ice mold  102 . In the embodiment shown, the clips  172  include an upper end  174  that is shaped for engaging a slotted opening  108   b  in the lateral side surface  108  of the ice mold  102 . A lower end  176  of the clip  172  is shaped for allowing the clip  172  to attach to the bottom surface  106  of the ice mold  102 . In the embodiment shown, the upper end  174  is J-shaped for securing the clip  172  to the slotted opening  108   b  and the lower end  176  is S-shaped to attach the clip  172  to an elongated rib  106   b  extending along opposite edges of the bottom surface  106  of the ice mold  102 . The clip  172  is installed by inserting the upper end  174  into the slotted opening  108   b  and then rotating the clip  172  toward the ice mold  102  until the lower end  176  snaps or clips onto the elongated rib  106   b , or an equivalent feature of the ice mold  102 . The clips  172  are dimensioned and positioned to bias or maintain the ice maker evaporator  150  in intimate contact or abutment with the lateral side surfaces  108  of the ice mold  102 . It is contemplated that the ice maker evaporator  150  may be configured to snap into the respective recesses  108   a  on the lateral side surfaces  108  of the ice mold  102 . 
     The ice tray assembly  100  of the instant application employs a direct cooling approach, in which the ice maker evaporator  150  is in direct (or substantially direct) contact with the ice mold  102 . The ice pieces are made without cold air ducted from a remote location (e.g., a freezer) to create or maintain the ice. It is understood that direct contact is intended to mean that the ice maker evaporator  150  abuts the ice mold  102 . 
     Referring to  FIG.  7   , the air handler  70  includes an ice box evaporator assembly  200  that is connected to the ice maker evaporator  150 . The ice box evaporator assembly  200  includes an ice box evaporator tube  210  and a defrost element  214 . The ice box evaporator tube  210  has an inlet  210   a  where a refrigerant enters and an outlet  210   b  where the refrigerant exits the ice box evaporator tube  210 . The ice box evaporator tube  210  is formed to include several hair-pin or U-shaped bends and to pass through a plurality of fins  212 . The fins  212  are configured to improve the efficiency in removing heat from air passing over the ice box evaporator tube  210 . The defrost element  214  is positioned adjacent the ice box evaporator tube  210  for defrosting the same, when desired. 
     Still, although the term “evaporator” is used for simplicity, in yet another embodiment the ice maker evaporator  150  and ice box evaporator tube  210  could instead be a thermoelectric element (or other cooling element) that is operable to cool the ice mold  102  and the air flowing through the air handler  70 , respectively, to a sufficient temperature to maintain the ice pieces in the ice mold  102  and the ice bin  54  in a frozen condition. 
     Referring to  FIG.  8   , a schematic of a cooling system  300  for the refrigerator  20  is shown. The cooling system  300  includes conventional components, such as a freezer evaporator  302 , an accumulator  304  (optional), a compressor  306 , a condenser  308  and a dryer  312 . These components are conventional components that are well known to those skilled in the art and will not be described in detail herein. 
     A stepper valve  324  is connected to an outlet of the dryer  312 . It is contemplated that both the valve  324  and the dryer  312  may be positioned in a machine room (not shown) of the refrigerator  20 . The stepper valve  324  includes a single inlet  324   i  and three outlets  324   a ,  324   b ,  324   c . The inlet  324   i  is connected to the condenser  308  and optionally to the dryer  312 . The first outlet  324   a  is connected to a fresh food evaporator  330  for the fresh food compartment  24  via a first capillary tube  332 . The second outlet  324   b  of the stepper valve  324  is connected via a second capillary tube  334  to a first line  342  that connects an outlet of the fresh food evaporator  330  to the inlet end  162  ( FIG.  7   ) of the ice maker evaporator  150 . The third outlet  324   c  of the stepper valve  324  is connected via a third capillary tube  336  to a second line  352  that connects the outlet end  164  ( FIG.  7   ) of the ice maker evaporator  150  to the inlet  210   a  ( FIG.  7   ) of the ice box evaporator tube  210 . 
     The outlet  210   b  ( FIG.  7   ) of the ice box evaporator tube  210  is connected via a third line  362  to an inlet of the freezer evaporator  302  for the freezer compartment  22 . An outlet of the freezer evaporator  302  is connected via a fourth line  372  to an inlet of the accumulator  304 . 
     When the valve  324  is in a first position (i.e., in through the inlet  324   i  and out through the first outlet  324   a ) the refrigerant flows along the flow path “A” through the first capillary tube  332 , through the fresh food evaporator  330  and enters the inlet end  162  ( FIG.  7   ) of the ice maker evaporator  150 , flows through the ice maker evaporator  150 , exits the outlet end  164  ( FIG.  7   ), enters the inlet  210   a  ( FIG.  7   ) of the ice box evaporator tube  210 , flows through the ice box evaporator tube  210 , exits the outlet  210   b  ( FIG.  7   ) of the ice box evaporator tube  210  and flows through the freezer evaporator  302  before returning to the accumulator  304 . 
     When the valve  324  is in a second position (i.e., in through the inlet  324   i  and out through the second outlet  324   b ), the refrigerant flows along the flow path “B” through the second capillary tube  334  enters the inlet end  162  ( FIG.  7   ) of the ice maker evaporator  150 , flows through the ice maker evaporator  150 , exits the outlet end  164  ( FIG.  7   ), enters the inlet  210   a  ( FIG.  7   ) of the ice box evaporator tube  210 , flows through the ice box evaporator tube  210 , exits the outlet  210   b  ( FIG.  7   ) of the ice box evaporator tube  210  and flows through the freezer evaporator  302  before returning to the accumulator  304 . As such, when the valve  324  is in the second position the refrigerant bypasses the fresh food evaporator  330 . 
     When the valve  324  is in a third position (i.e., in through the inlet  324   i  and out through the third outlet  324   c ), the refrigerant flows along the flow path “C” through the third capillary tube  336  enters the inlet  210   a  ( FIG.  7   ) of the ice box evaporator tube  210 , flows through the ice box evaporator tube  210 , exits the outlet  210   b  ( FIG.  7   ) of the ice box evaporator tube  210  and flows through the freezer evaporator  302  before returning to the accumulator  304 . As such, when the valve  324  is in the third position the refrigerant bypasses the fresh food evaporator  330  and the ice maker evaporator  150 . 
     During an ice harvesting process, a full bucket mode (i.e., the ice bucket is full and cannot accept more ice), or when the ice maker  50  is “OFF,” the valve  324  is in the third position such that the third outlet  324   c  is fluidly connected to the ice box evaporator tube  210  and the refrigerant bypasses the fresh food evaporator  330  and the ice maker evaporator  150 . During other processes/modes of operation wherein the temperature of the fresh food compartment  24  is at or below a target temperature, the valve  324  is in the second position such that the second outlet  324   b  is fluidly connected to the ice maker evaporator  150  and the refrigerant bypasses the fresh food evaporator  330 . During other processes/modes of operation wherein the temperature of the fresh food compartment  24  is above a target temperature, the valve  324  is in the first position such that the first outlet  324   a  of the valve  324  is connected to the fresh food evaporator  330  and none of the evaporators of the cooling system  300  are bypassed. 
     In the embodiment illustrated in  FIG.  8   , the fresh food evaporator  330 , the ice maker evaporator  150 , the ice box evaporator tube  210  and the freezer evaporator  302  are all disposed in series, in that order. As described in detail above, the cooling system  300  is configured such the stepper valve  324  selectively directs a refrigerant through: 1) all four evaporators  330 ,  150 ,  210 ,  302  in the series, 2) through only the last three evaporators  150 ,  210 ,  302  in the series, or 3) through only the last two evaporators  210 ,  302  in the series. 
       FIG.  9    illustrates a second embodiment wherein only the ice maker evaporator  150 , the ice box evaporator tube  210  and the freezer evaporator  302  are disposed in series in a path and this path is parallel to a path wherein the fresh food evaporator  330  is disposed. The fresh food evaporator  330  is connected to the first outlet  324   a  of the stepper valve  324  by the first capillary tube  332  and the fresh food evaporator  330  is connected to the second line  352  that connects the ice maker evaporator  150  to the ice box evaporator tube  210  by the first line  342 . 
     The inlet end  162  ( FIG.  7   ) of the ice maker evaporator  150  is connected to the second outlet  324   b  of the stepper valve  324  by the second capillary tube  334  and the outlet end  164  of the ice maker evaporator  150  is connected to the inlet  210   a  of the ice box evaporator tube  210  by the second line  352 . 
     The second line  352  is connected to the third outlet  324   c  of the stepper valve  324  by the third capillary tube  336 . The outlet  210   b  of the ice box evaporator tube  210  is connected by line  362  to the freezer evaporator  302  which, in turn, is connected to the accumulator  304  by the fourth line  372 . 
     When the valve  324  is in a first position (i.e., in through the inlet  324   i  and out through the first outlet  324   a ) the refrigerant flows along the flow path “A” through the first capillary tube  332  and the fresh food evaporator  330 . Upon exiting the fresh food evaporator  330 , the refrigerant flows through the second line  352 , enters the inlet  210   a  of the ice box evaporator tube  210 , flows through the ice box evaporator tube  210 , exits through the outlet  210   b  of the ice box evaporator tube  210  and flows through the freezer evaporator  302  before returning to the accumulator  304 . As such, when the valve  324  is in the first position the refrigerant bypasses the ice maker evaporator  150 . 
     When the valve  324  is in a second position (i.e., in through the inlet  324   i  and out through the second outlet  324   b ), the refrigerant flows along the flow path “B” through the second capillary tube  334 , enters the inlet end  162  of ice maker evaporator  150  and flows through the ice maker evaporator  150 . Upon exiting the outlet end  164  of the ice maker evaporator  150 , the refrigerant flows through the second line  352 , enters the inlet  210   a  of the ice box evaporator tube  210 , flows through the ice box evaporator tube  210 , exits through the outlet  210   b  of the ice box evaporator tube  210  and flows through the freezer evaporator  302  before returning to the accumulator  304 . As such, when the valve  324  is in the second position the refrigerant bypasses the fresh food evaporator  330 . 
     When the valve  324  is in a third position (i.e., in through the inlet  324   i  and out through the third outlet  324   c ), the refrigerant flows along the flow path “C” through the third capillary tube  336 , through the second line  352 , enters the inlet  210   a  of the ice box evaporator tube  210 , flows through the ice box evaporator tube  210 , exits through the outlet  210   b  of the ice box evaporator tube  210  and flows through the freezer evaporator  302  before returning to the accumulator  304 . As such, when the valve  324  is in the third position the refrigerant bypasses both the ice maker evaporator  150  and the fresh food evaporator  330 . 
     During an ice harvesting process, a full bucket mode (i.e., the ice bucket is full and cannot accept more ice), or when the ice maker  50  is “OFF” and the temperature of the fresh food compartment  24  is at or above a desired temperature, the valve  324  is in the first position such that the first outlet  324   a  is fluidly connected to the fresh food evaporator  330  and the refrigerant bypasses the ice maker evaporator  150 . During an ice harvesting process, a full bucket mode, or when the ice maker  50  is “OFF” and the temperature of the fresh food compartment is below the desired temperature, the valve  324  is in the third position such that the third outlet  324   c  is fluidly connected to the ice box evaporator tube  210  and the refrigerant bypasses the ice maker evaporator  150  and the fresh food evaporator  330 . During other processes/modes of operation, the valve  324  is in the second position such that the second outlet  324   b  of the valve  324  is connected to the ice maker evaporator  150  and bypasses the fresh food evaporator  330 . 
     The switching of the valve  324  is designed to reduce the operational cost of the cooling system  300  for the ice maker  50 . For simplicity, the housing of the air handler assembly  70  is not shown in  FIG.  7   . Arrows in  FIG.  7    illustrate that path of the refrigerant through the ice maker evaporator  150  and the ice box evaporator tube  210 . 
     Referring to  FIG.  10   , the ice maker  50  includes a circulation fan  64 . The ice box evaporator tube  210  is disposed proximate the circulation fan  64  such that air is drawn from the ice bin  54 , over the ice box evaporator tube  210  and back to the ice bin  54 . It is contemplated that the circulation fan  64  may be a centrifugal or squirrel-cage type fan wherein air is drawn into a center of the fan  64  and then exhausted radially away from the fan. It is also contemplated that the circulation fan  64  may be an axial fan wherein air is conveyed through the fan along a rotational axis of the fan. It is contemplated that the ice box evaporator tube  210  may include a defrost element  214  ( FIG.  7   ) that may be energized during a defrost cycle of the ice box evaporator tube  210 . The defrost element  214  may be configured such that heat generated by the defrost element  214  is sufficient to defrost both the ice box evaporator tube  210  and the fill cup  136  ( FIG.  5   ) of the ice tray assembly  100 . 
     In addition or alternatively, the ice maker of the present application may further be adapted to mounting and use on a freezer door. In this configuration, although still disposed within the freezer compartment, at least the ice maker (and possibly an ice bin) is mounted to the interior surface of the freezer door. It is contemplated that the ice mold and ice bin can be separated elements, in which one remains within the freezer cabinet and the other is on the freezer door. 
     Cold air can be ducted to the freezer door from an evaporator in the fresh food or freezer compartment, including the system evaporator. The cold air can be ducted in various configurations, such as ducts that extend on or in the freezer door, or possibly ducts that are positioned on or in the sidewalls of the freezer liner or the ceiling of the freezer liner. In one example, a cold air duct can extend across the ceiling of the freezer compartment, and can have an end adjacent to the ice maker (when the freezer door is in the closed condition) that discharges cold air over and across the ice mold. If an ice bin is also located on the interior of the freezer door, the cold air can flow downwards across the ice bin to maintain the ice pieces at a frozen state. The cold air can then be returned to the freezer compartment via a duct extending back to the evaporator of the freezer compartment. A similar ducting configuration can also be used where the cold air is transferred via ducts on or in the freezer door. The ice mold can be rotated to an inverted state for ice harvesting (via gravity or a twist-tray) or may include a sweeper-finger type, and a heater can be similarly used. It is further contemplated that although cold air ducting from the freezer evaporator as described herein may not be used, a thermoelectric chiller or other alternative chilling device or heat exchanger using various gaseous and/or liquid fluids could be used in its place. In yet another alternative, a heat pipe or other thermal transfer body can be used that is chilled, directly or indirectly, by the ducted cold air to facilitate and/or accelerate ice formation in the ice mold. Of course, it is contemplated that the ice maker of the instant application could similarly be adapted for mounting and use on a freezer drawer. 
     Alternatively, it is further contemplated that the ice maker of the instant application could be used in a fresh food compartment, either within the interior of the cabinet or on a fresh food door. It is contemplated that the ice mold and ice bin can be separated elements, in which one remains within the fresh food cabinet and the other is on the fresh food door. 
     In addition or alternatively, cold air can be ducted from another evaporator in the fresh food or freezer compartment, such as the system evaporator. The cold air can be ducted in various configurations, such as ducts that extend on or in the fresh food door, or possibly ducts that are positioned on or in the sidewalls of the fresh food liner or the ceiling of the fresh food liner. In one example, a cold air duct can extend across the ceiling of the fresh food compartment, and can have an end adjacent to the ice maker (when the fresh food door is in the closed condition) that discharges cold air over and across the ice mold. If an ice bin is also located on the interior of the fresh food door, the cold air can flow downwards across the ice bin to maintain the ice pieces at a frozen state. The cold air can then be returned to the fresh food compartment via a ducting extending back to the compartment with the associated evaporator, such as a dedicated icemaker evaporator compartment or the freezer compartment. A similar ducting configuration can also be used where the cold air is transferred via ducts on or in the fresh food door. The ice mold can be rotated to an inverted state for ice harvesting (via gravity or a twist-tray) or may include a sweeper-finger type, and a heater can be similarly used. It is further contemplated that although cold air ducting from the freezer evaporator (or similarly a fresh food evaporator) as described herein may not be used, a thermoelectric chiller or other alternative chilling device or heat exchanger using various gaseous and/or liquid fluids could be used in its place. In yet another alternative, a heat pipe or other thermal transfer body can be used that is chilled, directly or indirectly, by the ducted cold air to facilitate and/or accelerate ice formation in the ice mold. Of course, it is contemplated that the ice maker of the instant application could similarly be adapted for mounting and use on a fresh food drawer. 
     The invention has been described with reference to the example embodiments described above. Modifications and alterations will occur to others upon a reading and understanding of this specification. Examples embodiments incorporating one or more aspects of the invention are intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.