Abstract:
An ice maker mechanism provides a position sensor sensing the position of the ice tray to allow control of absolute position of the ice tray without the need for motor stalling such as generates heat and wastes energy. An ice maker mechanism provides two motors for rotating the ice tray adapted for high torques low-speed rotation and low torque high-speed rotation the latter used for agitation of the water during freezing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. provisional applications 61/804,018 filed Mar. 21, 2013 and 61/722,414 filed Nov. 5, 2012 both hereby incorporated in their entirety by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to ice making machines for home refrigerators and the like and specifically to an ice-making machine providing multiposition feedback with respect to an ice-maker motor position. 
       BACKGROUND OF THE INVENTION 
       [0003]    Household refrigerators commonly include automatic ice-makers located in the freezer compartment. A typical ice-maker provides an ice cube mold positioned to receive water from an electric valve that may open for a predetermined time to fill the mold. The water is allowed to cool until a temperature sensor attached to the mold detects a predetermined low-temperature point where ice formation is ensured. At this point, the ice is harvested from the mold by a drive mechanism into an ice bin positioned beneath the ice mold. 
         [0004]    The ice harvesting mechanism may, in one example, distort the ice mold to remove the “cubes” by twisting one end of the flexible ice tray when the other end abuts a stop. After a brief period of time during which the motor twisting the ice mold may stall and during which the ice cubes may be ejected from the tray, the motor is reversed in direction to bring the ice tray back to its fill position for refilling. Alternatively, the cubes may be ejected by rotating an ejector comb that sweeps through the tray to remove the cubes. At the end of the ejection cycle, the tray or comb returns to a home position as may be detected by a limit switch. 
         [0005]    An ice sensor may be provided to determine when the ice-receiving bin is full. One sensor design periodically lowers a bail arm into the ice bin after each harvesting to gauge the amount of ice in the bin. If the bail arm&#39;s descent, as determined by a limit switch, is limited by ice filling the bin to a predetermined height, harvesting is suspended. 
       SUMMARY OF THE INVENTION  
       [0006]    Allowing the motor to stall unnecessarily consumes electrical energy. Detecting multiple positions of the motor during operation, however, requires either multiple electrical switches or other sensors which can be relatively expensive. 
         [0007]    The present invention provides a motor for an ice-maker mechanism that includes an integrated encoder detecting motor position allowing a number of different motor positions to be detected at relatively low incremental cost. By detecting the motor positions, motor current may be stopped during periods when otherwise the motor would stall. The encoder may be realized by a printed circuit board that also implements a switch for the ice bail arm and which supports an integrated connector providing all power and signals to and from the ice-maker system. 
         [0008]    Specifically, the present invention provides an ice making apparatus having a housing with a front wall adapted to be positioned adjacent to an ice mold for molding ice cubes. A rotatable shaft is through the front wall and position sensor communicates with the rotatable shaft to provide an electrical position signal indicating a position of the rotatable shaft. Electrical conductors attach to the position sensor to communicate the electrical position signal to an electrical controller for controlling ice making. 
         [0009]    It is thus a feature of at least one embodiment of the invention to provide absolute positioning of the ice tray or comb without the need for multiple discrete switches or motor stalling. 
         [0010]    The ice making apparatus may include an electrical motor communicating with the rotatable shaft to receive electrical signals from the electrical connector and the controller may control the electrical motor according to electrical position signal. 
         [0011]    It is thus a feature of at least one embodiment of the invention to permit sophisticated remote control of the ice making mechanism for example by a microprocessor positioned elsewhere in the refrigerator. 
         [0012]    The electrical position signal may encode a position of the rotatable shaft in a magnitude of voltage or current. 
         [0013]    It is thus a feature of at least one embodiment of the invention to provide a reduced wiring harness that can communicate position signals to a remote control device. By encoding position into a voltage a single wire pair may replace multiple wire pairs that might be required for separate switches. 
         [0014]    The position sensor may provide a set of electrically switched connections communicating with a resistor ladder to provide a position signal in the form of a voltage dependent on a state of the electrically switched connections as they change with rotation of the position sensor. 
         [0015]    It is thus a feature of at least one embodiment of the invention to provide a simple method of encoding switch positions into a voltage. 
         [0016]    The position sensor may include a printed circuit board positioned to extend perpendicularly to the rotatable shaft near the rotatable shaft and providing traces having arcuate surfaces concentric about an axis of rotation of the rotatable shaft selectively interconnected by a wiper rotating with the rotatable shaft to implement the set of electrically switched connections. 
         [0017]    It is thus a feature of at least one embodiment of the invention to provide a low-cost position encoder in the form of a multi-pole switch. 
         [0018]    The encoder may include a magnet element attached for rotation with the rotatable shaft, the magnet element providing circumferentially periodic magnetic polarity zones and further including a Hall effect sensor positioned adjacent to the magnetic element to provide electrically switched connections that vary with rotation of the magnet element to provide an electrical position signal. 
         [0019]    It is thus a feature of at least one embodiment of the invention to provide an encoder that may provide high resolution position information with the relatively simple mechanism. 
         [0020]    The encoder may include a magnet element attached for rotation with the rotatable shaft, and further including multiple angularly displaced Hall effect sensors positioned along a path of the magnetic element with rotation of the rotatable shaft to provide electrically switched connections that vary with rotation of the magnet element to provide an electrical position signal. 
         [0021]    It is thus a feature of at least one embodiment of the invention to provide an encoder using low-cost but robust solid-state switching elements. 
         [0022]    The electrical conductors may provide a releasable electrical connector including electrical connector pins attached to a printed circuit board in the housing to extend through the housing to provide electrical communication to the printed circuit board and the housing may provide an integrated connector shell for surrounding the electrical connector pins to guide and retain a corresponding mating connector. 
         [0023]    It is thus a feature of at least one embodiment of the invention to provide a cost reduced icemaker eliminate the need for a separate molded connector. 
         [0024]    The housing may have interfitting front and back portions each supporting part of the connector shell and together providing a shroud surrounding the connector pins. 
         [0025]    It is thus a feature of at least one embodiment of the invention to integrate the connector shell into the housing in a manner that provides simplified molding. By splitting the connector shell between housing halves an additional mold core may be eliminated. 
         [0026]    The housing may further include right and left sidewalls flanking the front wall and may hold a second rotatable shaft extending from at least one of the right and left side walls at an end. Eight reciprocating mechanism may communicate with the first rotational shaft to provide reciprocation of the second rotatable shaft with rotation of the first rotatable shaft and a bail arm may be attached to the end. A second position sensor may communicate with the second rotatable shaft to sense a position of the bail arm. 
         [0027]    It is thus a feature of at least one embodiment of the invention to provide remote sensing of the bail arm for sophisticated control of the ice making machine by a central controller. 
         [0028]    The second position sensor may be electrical switch having contacts formed on the printed circuit board contacting contacts movable with the second rotatable shaft. 
         [0029]    It is thus a feature of at least one embodiment of the invention to implement bail arm position sensing in a way that makes efficient use of a printed circuit board that may also be used with the first position sensor. 
         [0030]    Alternatively, the second position sensor may be a magnet sensor activated by a magnet on the second rotatable shaft. 
         [0031]    It is thus a feature of at least one embodiment of the invention to extend magnetic sensing usable in sensing the position of the first rotating shaft to sensing position of the bail arm. 
         [0032]    The present invention further provides an ice making mechanism that may be adapted to operate in two modes: (1) to move the ice tray through a relatively large angle as part of the cycle of filling and ejecting the ice tray and (2) to move the ice tray through a relatively small angle to agitate water during freezing, for example, to promote reduced ice cloudiness or the like. 
         [0033]    Specifically, in this embodiment, the invention provides an ice making apparatus having a housing with a front wall adapted to be positioned adjacent to an ice mold for molding ice cubes and a rotatable shaft exposed through the front wall. A brushless motor communicates with the rotatable shaft to rotate the rotatable shaft in a first mode of operation for agitating freezing water and a brush motor communicates with the rotatable shaft to rotate the rotatable shaft in a second mode of operation for releasing ice. 
         [0034]    It is thus a feature of at least one embodiment of the invention to provide a dual mode of operation with increased operating life. By separating the task of low-frequency high torque ice ejection and high-frequency low torque agitation, a low torque brushless motor with improved wear characteristics may be used for the agitation task. 
         [0035]    The brushless motor may be a stepper motor. 
         [0036]    It is thus a feature of at least one embodiment of the invention to employ a brushless motor with high torque low-speed characteristics. It is a feature released one embodiment of the invention to employ a motor well adapted for open loop control to eliminate the need for high resolution position sensing. 
         [0037]    The ice making apparatus may include a power transmitting element engaging the brushless motor over a first range of rotation of the first shaft and engaging the brush motor over a second range of rotation of the first shaft different from the first range. 
         [0038]    It is thus a feature of at least one embodiment of the invention to reduce unnecessary where on the non-operative motor. It is a feature of at least one embodiment of the invention to permit a torque increasing speed reduction gears on the brush motor which if not disconnected from the rotatable shaft would prevent movement of the rotatable shaft by a directly connected brushless motor. 
         [0039]    The ranges may overlap. 
         [0040]    It is thus a feature of at least one embodiment of the invention to ensure positive connection of the rotatable shaft to at least one motor at all times. 
         [0041]    The power transmitting elements may provide a gear having teeth along only a portion of its periphery to selectively engage corresponding gears driven by the brush motor and brushless motor in the first range of rotation and second range of rotation. 
         [0042]    It is thus a feature of at least one embodiment of the invention to provide a simple method for connecting and disconnecting the two motors over predetermined ranges. 
         [0043]    The brush motor may provide a speed reduction gear train between the brush motor and the rotatable shaft. 
         [0044]    It is thus a feature of at least one embodiment of the invention to permit the use of low-cost brush motors. 
         [0045]    Alternatively, the power transmitting mechanism may be a stop surface attached to a rotatable drive element driven by the brush motor, the stop surface engaging a concentrically rotating arm attached to the rotatable shaft driven by the brushless motor, the stop surface also engaging the rotating arm when the arm passes beyond a predetermined angular position with respect to rotatable drive element so that the rotating arm may reciprocate within a predetermined angular range without engagement with the rotatable drive element. 
         [0046]    It is thus a feature of at least one embodiment of the invention to provide a power transmitting mechanism that mediates between two motors while always allowing the brush motor to remain engaged, for example, in the event of failure of the brushless motor. 
         [0047]    The ice making apparatus may include temperature sensor signal conductors attached to rotate with the rotatable shaft and adapted for communication with a temperature sensor in an ice tray attached to the rotatable shaft and further including a slip ring system attached between the rotatable drive element and circuitry fixed with respect to the housing. The apparatus may further include contacts for connecting the signal conductors on the rotatable shaft with a portion of the slip ring system on the rotatable drive element only when the rotating arm engages the rotatable drive element. 
         [0048]    It is thus a feature of at least one embodiment of the invention to provide a slip ring system for communicating temperature information from the rotating ice tray that is not adversely affected by repeated high cycle agitation of the ice tray such as might wear out the slip ring surfaces. 
         [0049]    Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0050]      FIG. 1  is an exploded front elevational view of an ice-maker motor assembly such as may rotate an ice tray for filling and harvesting of ice into an ice bin and showing a bail arm integrated to the ice-maker motor assembly for detecting ice height; 
           [0051]      FIG. 2  is a front perspective view of a drive gear of the motor mechanism such as communicates by a shaft to the ice mold and which supports a first wiper assembly on a front face of the drive gear that interacts with arcuate traces on a printed circuit board to provide an encoder-like indication of motor position and showing bail arm contact pads on that printed circuit board that may interact with a second wiper assembly on the bail arm for detecting bail arm position; 
           [0052]      FIG. 3  is a rear elevational view of the printed circuit board of  FIG. 2  showing the traces that interact with the first and second wiper assemblies of  FIG. 2  and an integrated multi-pin connector; 
           [0053]      FIG. 4  is an electrical schematic of the circuit implemented by the printed circuit board and wiper assemblies of  FIG. 2 ; 
           [0054]      FIG. 5  is an exploded fragmentary view of a housing of the ice-maker motor assembly showing a housing-integrated connector shell having connector pins directly attached to the printed circuit board; 
           [0055]      FIG. 6  is a figure similar to that of  FIG. 2  in which the encoder-like indication of motor position is provided by Hall effect sensors on the printed circuit board and a magnet on a front face of the drive gear and wherein the position of the bail arm is also indicated by interaction of a magnet on the bail arm and Hall effect sensors on the printed circuit board; 
           [0056]      FIG. 7  is a figure similar to that of  FIG. 4  showing the electrical schematic of the circuit implemented by the sensor system of  FIG. 6 ; 
           [0057]      FIG. 8  is a front perspective view of the drive gear of  FIG. 6  showing a driving of the drive gear by either of two output gears, the first driven by a brushless motor and the second driven by a brush motor behind the drive gear; 
           [0058]      FIG. 9  is a fragmentary rear perspective view of the drive gear of  FIG. 8  showing positioning of the brush motor behind the drive gear; 
           [0059]      FIGS. 10   a - 10   c  are simplified views of the output gears and drive gear of  FIG. 8  showing their operation with various positions of the drive gear and corresponding ice tray and bail arm; 
           [0060]      FIG. 11  is a rear perspective view similar to that of  FIG. 9  showing a brushless motor integrated into the drive gear which operates as the brushless motor rotor; 
           [0061]      FIG. 12  is an exploded perspective view of a dual drive system similar in purpose to those depicted in  FIGS. 8-11  showing a power transmission system for mediating between two motors through the use of interengaging stops and further showing a slip ring system for transmitting temperature sensor information from the ice tray to a stationary circuit card; 
           [0062]      FIG. 13  is a cross-sectional view along lines  13 - 13  of  FIG. 12  showing contacts for communicating between the slip rings and the thermocouple during an interengagement of the stops of  FIG. 12 ; and 
           [0063]      FIGS. 14   a  and  14   b  are figures showing operation of the power transmission system of  FIG. 12  in providing decoupling of the brushless motor and the brush motor during an agitation cycle. 
       
    
    
       [0064]    Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0065]    Referring now to  FIG. 1 , an ice-maker  10  may include an ice mold  12  for receiving water and molding it into frozen ice cubes  17  of arbitrary shape. The ice mold  12  may be positioned adjacent to ice harvest drive mechanism  14  operating to remove cubes from the mold when they are frozen, for example, by inversion and distortion of the ice mold  12  or use of an ejector comb (not shown). The ice mold  12  may be positioned above an ice storage bin  15  for receiving cubes  17  therein when the latter are ejected from the ice mold  12 . 
         [0066]    The ice harvest drive mechanism  14  may have a drive coupling  16  exposed at a front wall  18  of a housing  20  of the ice harvest drive mechanism  14  and communicating with the mold  12  or comb. The drive coupling  16  may rotate about an axis  22  along which the ice mold  12  or comb extends. 
         [0067]    The right wall  24  of the housing  20 , flanking the front wall  18 , may support one end of a bail arm  30  extending generally parallel to axis  22  allowing the bail arm  30  to pivot about a horizontal axis  32  generally perpendicular to axis  22  and extending from the right wall  24 . As so attached, the opposed cantilevered end of the bail arm  30  may swing down into the ice storage bin  15  to contact an upper surface of the pile of cubes  17  in the ice storage bin  15  to determine the height of those cubes  17  and to deactivate the ice-maker  10  when a sufficient volume of cubes  17  is in the ice storage bin  15 . 
       Encoder Using Mechanical Wiper 
       [0068]    Referring now to  FIGS. 1 and 2 , the bail arm  30  may be a thermoplastic material and attached to a rotatable shaft  36  extending along axis  32  through the housing  20 . Also attached to the shaft  36  within the housing  20  may be a first wiper assembly  40  having electrically joined flexible wiper fingers  42 . The flexible wiper fingers may rotate with the shaft  36  to bridge across printed circuit contact pads  44  on a printed circuit board  46  positioned inside the housing  20  when the bail arm  30  is fully descended. With such contact, the printed circuit contact pads  44  are shorted together. When the bail arm  30  cannot fully descend as obstructed by a filling of the ice storage bin  15  with ice cubes  17 , the flexible wiper fingers  42  are stopped away from the printed circuit contact pads  44  so that the printed circuit contact pads  44  are electrically separated. 
         [0069]    The drive coupling  16  may be a center hub of a drive gear  50  being part of a gear train  52  ultimately driven by a permanent magnet reversible DC motor (not shown in  FIG. 2  but to be discussed with respect to  FIG. 4 ). The gear train  52  provides an increase in torque and the reduction in rotation speed of the motor to turn the drive gear  50  at about two revolutions per minute. A front face  54  of the drive gear  50 , generally normal to axis  22 , supports a second wiper assembly  56  presenting electrically joined flexible wiper fingers  57  that may contact respective arcuate traces  58  on the printed circuit board  46  with rotation of the gear  50  about axis  22 . 
         [0070]    Generally a cam system (not shown) between the shaft  36  and other elements of the gear train  52  (for example a cam on a reverse face of the drive gear  50 ) may interact so that rotation of the drive gear  50  raises and drops the bail arm  30  appropriately during operation of the ice-maker  10 . 
         [0071]    Referring to  FIGS. 2 ,  3 , and  4 , the printed circuit board  46  may support on an opposite face a five-pin electrical connector  60  that may be physically staked to the printed circuit board  46  and whose connector pins  62  may communicate, for example, by solder connections with printed circuit board traces  64  to various components on the circuit board  46  including resistors  66 , the printed circuit contact pads  44 , and the arcuate traces  58 . The inner arcuate trace  58   a  may be generally continuous to provide for a conductor that may continuously connect with the second wiper assembly  56  throughout a range of positions of the drive coupling  16 . In contrast, the outer arcuate trace  58   b  may be divided into different annular sectors  68   a - 68   c  (possibly separated by grounded sectors) that are electrically isolated from each other to provide for multiple throws of a rotary switch completed by the pole formed by the second wiper assembly  56  connecting through arcuate trace  58   a.  The sector  68   a  may be positioned directly above an axis of the drive coupling  16  at a 12 o&#39;clock position, the sector  68   b  may be positioned to the side of an axis of the drive coupling  16  at a nine o&#39;clock position (as viewed from the rear) and the sector  68   c  may be positioned directly below an axis of the drive coupling  16  at a six o&#39;clock position as will be discussed further below. 
         [0072]    Each of the separate sectors  68  of the outer arcuate trace  58   b  may communicate with a different node  70  of a resistor ladder  67 , each node represented by connections between series connected resistors  66  forming the resistor ladder  67 . The ends of the resistor ladder  67  may be connected between one pin  62  of connector  60  providing a positive DC voltage source  72  and one pin  62  providing a drive return  74 . Accordingly, each of the nodes  70  will have a different voltage that may be communicated through the annular sectors  68  and the second wiper assembly  56  to the arcuate trace  58   a  and from there to one pin  62  of the connector  60  providing a position output line  76  whose voltage will be dependent on the rotation of the drive coupling  16  in the manner of an encoder. 
         [0073]    One of the contact pads  44  may be connected to the ground  77  and the other contact pads  44  in sector  68   c  provide the lowest voltage tap on the resistor ladder of resistors  66  thereby providing an ice level signal by a pulling of output line  76  to ground. Finally, one pin  62  may be dedicated to providing a drive voltage  79  to the motor  80  driving the gear train with the other terminal of the motor  80  connected to the drive return  74  separate from ground  77  to allow a direction of drive of the motor  80  to be reversed by reversing the polarity of drive voltage  79  and drive return  74 . 
         [0074]    Referring to  FIG. 1 , connector  60  may be exposed at the right wall  24  of the ice harvest drive mechanism  14  to connect with a mating connector  82  for communicating with a control system  83  for the refrigerator. The control system  83  may be a microprocessor executing a stored program to control the ice-maker  10  as described herein as well as other refrigerator functions. 
         [0075]    Example constructions of the gear train  52  and of other elements and components of the ice harvest drive mechanism  14  are described in US patent application 2012/0186288 hereby incorporated in its entirety by reference. 
       Integrated Connector Shell 
       [0076]    Referring momentarily to  FIG. 2 , the connector  60  may include a connector shell  84  surrounding the connector pins  62  to provide an assembly that may be attached to the printed circuit board  46 . Alternatively, as shown in  FIG. 5 , the connector pins  62  may be retained in a header  86  for direct attachment to the printed circuit board  46  without a connector shell  84 . Instead, an effective connector shell may be provided by means of a tray  88  extending outward along axis  32  from side wall  24  as integrally molded into the side wall  24  of the housing  20  in the vicinity of the pins  62 . The tray  88  may provide for bottom and flanking walls to guide corresponding bottom and side walls of the mating connector  82  for receiving a lower half of the connector  82  and guiding it axially along axis  32  into electrical engagement with pins  62 . An upper portion of the effective shell for the pins  62  may be provided by the front wall  18 . 
         [0077]    The mating connector  82  may have a snap tab  90  that may be received by a corresponding tooth  92  formed in the front wall  18 . By eliminating the connector shell  84 , (shown in  FIG. 2 ) a lower-cost and thinner product may be created. 
       Encoder Using Hall Effect Sensors 
       [0078]    Referring now to  FIGS. 1 and 6 , the rotatable shaft  36  of the bail arm  30  may alternatively support a radially extending magnet arm  41  having a magnet  43  at its distal end to move past a Hall effect sensor  100  on the printed circuit board  46 . The magnet  43  may rotate with the shaft  36  to activate the Hall effect sensor  100  on a printed circuit board  46  when the bail arm  30  has fully descended. When the bail arm  30  cannot fully descend, as obstructed by a filling of the ice storage bin  15  with ice cubes  17 , the magnet  43  is stopped away from the Hall effect sensor  100  so that Hall effect sensor  100  is not activated. 
         [0079]    A front face  54  of the drive gear  50 , generally normal to axis  22 , supports a second magnet  102  that may activate respective Hall effect sensors  104   a - 104   c  on the printed circuit board  46  with rotation of the drive gear  50  about axis  22 . The Hall effect sensors  104   a - 104   c  are positioned generally at a 12 o&#39;clock position for Hall effect sensor  104   a  directly above axis  22 , a three o&#39;clock position for Hall effect sensor  104   b  (as seen from the front) and a six o&#39;clock position for Hall effect sensor  104   c  to allow detection of the position of the drive gear  50  in approximate 90 degree increments. 
         [0080]    As before, a cam system (not shown) between the shaft  36  and other elements of the gear train  52  (for example a cam on a reverse face of the drive gear  50 ) may interact with the bail arm  30  so that rotation of the drive gear  50  raises and drops the bail arm  30  appropriately during operation of the ice-maker  10 . 
         [0081]    Referring to  FIGS. 2 ,  6 , and  7 , the printed circuit board  46  may conduct binary digital signals from each of the Hall effect sensors  104   a - 104   c  to be received, for example, at different digital control inputs of a multiplexer  110 , such as a CD4051 multiplexer commercially available from Texas Instruments. The binary signals form a binary word input to the multiplexer  110  to control a connection of output line  76  (similar to that the described above) to one of four different input lines  112  connected to nodes  70  of a resistor ladder formed from resistors  66 . In this way, depending on the binary word input to the multiplexer  110 , a different nonzero voltage is provided from the resistor ladder to output line  76 . A nonzero voltage is provided to output line  76  even when the multiplexer receives a zero input where none of the Hall effect sensors  100  are activated. 
         [0082]    The Hall effect sensor  100  associated with the bail arm  30  may be connected to the inhibit line of the multiplexer  110  to disconnect each of the lines  112  from the output line  76  to allow the output line  76  to be pulled to a zero state by a pulldown resistor  115  or the like. In this way the state of each of the sensors  104   a - 104   c  and Hall effect sensor  100  may be mapped to a different voltage value on output line  76 . 
       Dual Drive Mechanism 
       [0083]    Referring now to  FIGS. 8 and 9 , in one embodiment of the invention, peripheral teeth  120  of the drive gear  50  may cover only part of the outer circumference of the drive gear  50  to be selectively engaged by a first output gear  124  and/or a second output gear  126 . The first output gear  124  is associated with a brushless DC motor  122 , such as a stepper motor, while the second output gear  126  is associated with a DC brush motor  80  communicating with this DC brush motor  80  through a gear train  130 . Generally the brushless DC motor  122  will provide for lower torque but lower wear during operation (because of the lack of brushes) whereas the gear train  130  and brush motor  80  will provide for higher torque but somewhat greater wear with operation because of the brushes and higher torque associated with the gear train  130 . 
         [0084]    Referring now to  FIG. 10 , a when the drive gear  50  is in a first position as shown with the magnet  102  sensed by Hall effect sensor  104   a  (shown in  FIG. 6 ) in the 12 o&#39;clock position, the ice mold  12  may be in its upright position suitable for filling with water and the bail arm  30  may be in its raised position. At this time the outer peripheral teeth  120  engage only the output gear  124  which may be operated to reciprocate the drive gear  50  rapidly to agitate water in the mold  12  without spilling it for the purpose of improving ice formation. Output gear  126  at this time will be disconnected from the drive gear  50  because of the lack of teeth  120  at the periphery of the drive gear  50  in the vicinity of output gear  126 . 
         [0085]    Referring now to  FIG. 10   b , the output gear  124  may then be driven to rotate the drive gear  50  clockwise as shown to move the magnet  102  until it is sensed by Hall effect sensor  104   b  (shown in  FIG. 6 ) in the three o&#39;clock position. The output gear  126  remains at this point disconnected from the drive gear  50  by lack of teeth  120  in its proximity. The ice mold  12  is tipped at this point but is undistorted and does not discharge frozen contained ice cubes and the bail arm  30  is lowered to detect whether there are sufficient ice cubes in the bin  15  (shown in  FIG. 1 ). If there is sufficient ice, as determined by Hall effect sensor  100  (shown in  FIG. 6 ), output gear  124  may be reversed to restore the tray to its horizontal position shown in  FIG. 10   a . Otherwise, output gear  124  further rotates drive gear  50  in the clockwise direction so that teeth  120  engage output gear  126 . Now output gear  126  may be activated to assist or replace the torque provided by output gear  124  in rotating the mold  12  to its inverted position for the discharge of ice cubes  17  requiring the high torque associated with the output gear  124 . 
         [0086]    At the conclusion of discharge of the cubes  17 , output gear  124  may return the drive gear  50  to the position of  FIG. 10   a.    
         [0087]    Referring now to  FIG. 11 , in one embodiment, the output gear  124  may be eliminated in favor of a direct drive of an axial shaft  131  of the drive gear  50 . The axial shaft  131  may have a tubular central bore  132  extending along axis  22  that may be supported for rotation on a cylindrical post (not shown) also extending along axis  22  and affixed to the housing. The outer cylindrical surface of the axial shaft  131  may have a magnetic material  134  having alternating north and south polarizations as one moves in angle about axis  22 . A stator  136  may be positioned adjacent to the magnetic material  134  and include coils causing rotation of the shaft  131  by attraction and repulsion of the periodic magnetic poles of the magnetic material  134  as is understood in the art of stepper motor design. In other respects, the operation of the magnetic material  134  and stator  136  may be to duplicate a brushless DC motor  122  described above. 
         [0088]    It will be appreciated that logic circuitry may be provided to selectively activate either the brushless or brush motor depending on the angle of the drive gear  50  and the desired operation of the ice-maker. 
         [0089]    Referring now to  FIG. 12 , in an alternative system for connecting the DC brush motor  80  and brushless DC motor  122  to the ice mold  12 , the brushless DC motor  122  may directly drive the drive coupling  16  through a coaxial shaft  140 . The drive coupling  16 , in this embodiment, may include radially extending arms  142  diametrically opposed across axis  22 . Each of the radially extending arms  142  may provide electrical contact surface  144  on one front radially extending face of the radially extending arm  142 , the radially extending face being substantially normal to a tangent of rotation of the arms  142 . 
         [0090]    Each of the electrical contact surfaces  144  may communicate by internal electrical conductors to axially engage electrical connector pins  146  also attached to the drive coupling  16 . 
         [0091]    The electrical connector pins  146  allow connection to corresponding sockets  148  attached to the ice mold  12  at a point of attachment of the ice mold  12  with the drive coupling  16 . These sockets  148  may in turn communicate with a thermistor temperature sensor  150  embedded in the ice mold  12  for sensing the temperature of the ice cubes  17  in the ice mold  12 . The electrical connector pins  146  and corresponding sockets  148  provide a releasable electrical connector. 
         [0092]    The drive coupling  16  in this embodiment extends through a central hole in the gear  50 , the latter of which serves as a secondary drive element that may be driven by gear  126  through gear train  130  by brush motor  80 . As before, gear  50  may include wiper assembly  56  with joined flexible wiper fingers  57  communicating with arcuate traces  58   a  and  58   b  on printed circuit board  46  to provide a position encoding function as described above. 
         [0093]    Referring also to  FIG. 13 , drive gear  50  may provide two diametrically opposed wiper fingers  154  on the same surfaces as wiper fingers  154  for engaging arcuate slip rings  58   c  and  58   d  on the printed circuit board  46 . The slip rings  58   c  and  58   d,  like arcuate traces  58   a  and  58   b,  communicate with the connector pins  62  discussed above. 
         [0094]    Each of the wiper fingers  154  extends through openings  152  in the gear  50  to pass outward below the gear  50  as contact fingers  160 . When the arms  142  rotate beyond a predetermined range with respect to the gear  50 , a stop  162  on the inner surface of the gear  50  contacts the arms  142  to cause the gear  50  to move with the drive coupling  16 . At that time, the contact fingers  160  electrically connect to the electrical contact surfaces  144  on the arms  142  providing an electrical path from the thermistor  150  through connector pins  146 , through the electrical contact surface  144 , through contact fingers  160 , and through wiper fingers  154  to slip ring  58   c  or  58   d,  respectively. 
         [0095]    Referring now to  FIG. 14   a , during large angle rotation of the ice mold  12  of 360 degrees of rotation, the ice mold  12  is rotated by the drive coupling  16  as driven by rotation of the gear  50  (for example, counterclockwise rotation as depicted) which in turn is driven by the brush motor  80 . This rotation brings stop  162  into contact with the arms  142  of the drive coupling  16  so that the gear  50  and the drive coupling  16  rotate in tandem. Such large angle rotation, for example, may move the ice mold  12  from an inverted ice ejection position back into its upright position for filling and refreezing of the water in the ice mold  12 . During this large angle rotation, contact fingers  160  electrically connect to surfaces  144  allowing measurement of the temperature of thermistor  150  to be obtained by a remote device communicating through connector pins  62 . During this large angle rotation, the brushless motor ice mold  12  is deactivated and rotates passively. 
         [0096]    Referring now to  FIG. 14 , when the ice tray is in the upright and filled position, the drive coupling  16  may be directly driven by the stepper motor ice mold  12  with the brush motor  80  deactivated. First, arms  142  are moved clockwise away from the stop  162  and then back toward the stop  162  in a rapid reciprocating motion controlled by a counting of a number of step signals provided to the stepper motor ice mold  12 . By decoupling the wiper fingers  154  from the drive coupling  16  during this rapid reciprocation, excessive wear of the slip rings  58   c  and  58   d  is avoided. 
         [0097]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0098]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0099]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties