Abstract:
An apparatus, method, and system for automatically turning off an electrically powered actuator in a refrigeration mechanism upon detection of an unwanted condition. In one aspect of the invention, the electrically powered actuator can be the motor of an ice maker/dispenser. The detection can be accomplished by sensing the presence of an object along or near an ice dispensing pathway from the ice maker/dispenser. The unwanted condition could be the presence of the object for more than a preset time period. This would allow to distinguish between an unwanted object such as silverware or clogged ice versus a wanted object such as flowing ice cubes, crushed ice, or shaved ice.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. provisional application Ser. No. 60/882,636, filed Dec. 29, 2006, and 60/890,107, filed Feb. 15, 2007, which is incorporated herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to refrigeration mechanisms and, in particular, to such mechanisms that include electrically powered actuators. 
     2. Description of the Related Art 
     Modern refrigeration mechanisms, such as refrigerator/freezer units, have electrically powered actuators that perform a variety of functions. An example is an ice maker/dispenser. Normally, electrical motors perform functions such as operating valves to supply water to the ice maker, moving a rod or rack to eject ice that has been frozen from supplied water, and moving other structure to move, alter, or direct ice pieces to an ice delivery or dispensing chute. 
     In the case of an ice maker/dispenser, the user normally must manually push a button with a finger or move a glass or container against a lever to actuate the motors to dispense ice down the chute. In some models, the user can also manually push a button to select between ice cubes or crushed ice, and in some instances shaved ice. Normally, once actuated, the dispenser operates until the user releases the button or lever. In some cases, the dispenser motor continues until automatically stopped by a timer. 
     In either of these cases, there are situations where it may be desirable to automatically stop the dispensing motor even if the user has instructed it to continue. For example, if ice jams or clogs the ice dispensing chute, the user may continue to try to operate the dispensing motor. Ice would back up and potentially damage the system. Additionally, if a foreign object (a non-ice object) enters the chute, it would be advantageous to automatically detect the same and stop operation of the dispensing motor until the situation can be resolved. 
     Furthermore, maintenance is some times performed on the ice chute, or at or near the ice chute. It could be advantageous to disable the dispensing motor automatically. There are other reasons to stop moving parts, such as are obvious to those skilled in the art. 
     There can be other actuators in the form of motors, valves, fans, etc. that are electrically powered and may have moving parts or cause certain functions where it would be advantageous to have some sort of backup or failsafe automatic protection to disable or shut off the actuator for unwanted conditions. 
     SUMMARY OF THE INVENTION 
     It is therefore a principle object, aspect, feature and/or advantage of the present invention to provide an apparatus, method, and system which improves over or solves the problems and deficiencies in the art. 
     Further objects, aspects, features, and/or advantages of the present invention include, but are not limited to, an apparatus, method, or system for automatically detecting and disabling or turning off an electrically powered actuator in a refrigeration mechanism which: 
     a. prevents tampering, damage, or breakage of components of the refrigeration mechanism; 
     b. detects the difference between conditions indicative of an unwanted condition from a wanted condition for the refrigeration mechanism; 
     c. is robust, and durable, particularly in the environment of a refrigeration unit, where there can be a range of temperatures and moisture content; 
     d. detects ice and non-ice objects; 
     e. does not require contact with an object to sense an unwanted condition; and 
     f. is efficient and relatively economical. 
     A method according to one aspect of the invention comprises providing an electrically-powered actuator in a refrigeration mechanism, sensing the presence of an object along or a near sensing location, and turning off or disabling the actuator if the sensed presence of an object is indicative of an unwanted condition. 
     An apparatus according to an aspect of the present invention comprises a refrigeration mechanism with an electrical powered actuator, a sensor producing an electrical output signal in response to sensitivity to a measured property, the measured property comprising presence of an object at or near a sensing location; a control operatively connected to the sensor and the actuator, the controller issuing an instruction to stop or disable operation of the actuator based upon a parameter of the measured property of the sensor. 
     Another aspect of the present invention comprises a method or apparatus where the measured property comprises presence of an object at or near the sensing location and a parameter of the measured property is length of time of presence of the object at the sensing location. 
     A further aspect of the present invention is an apparatus or method as above described wherein the measured property of the sensor is transduced by measuring attenuation of the energy or agent capacitance of an electromagnetic field. 
     Another aspect of the present invention is a refrigeration mechanism comprising an ice maker including an electrically powered actuator, a dispensing chute, a sensor producing an electrical output signal in response to a measured property comprising presence of an object along or near an ice dispensing pathway defined by the ice dispensing chute, a controller connected to the sensor and actuator and adapted to issue an instruction to stop or disable operation of the actuator based on cumulative time of presence of an object at or near the ice dispensing pathway. 
     These and other objects, aspects, features, or advantages of the present invention will become more apparent with reference to the accompanying specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front elevation view of a refrigeration mechanism comprising a side-by-side refrigerator/freezer with an ice and water dispenser. 
         FIG. 2  is an enlarged isolated perspective view of an ice dispensing chute for delivering ice to the dispensing station of the refrigerator of  FIG. 1 , further showing diagrammatically an optical sensing system in operative communication with a controller and actuator (an ice maker/dispenser) of the refrigeration mechanism of  FIG. 1 . 
         FIG. 3  is an enlarged side sectional view of the ice and water dispensing station of the refrigeration mechanism of  FIG. 1  showing schematically an ice maker above the ice dispensing chute. 
         FIG. 4  is a perspective view of the exit opening of an alternative embodiment of an ice dispensing chute at a dispensing station. 
         FIG. 5  is a block diagram of electrical and electronic components for the optical sensing system of the simplified diagram of  FIG. 2 . 
         FIG. 6  is a flow chart of software programming for operation of the system of  FIG. 5 . 
         FIG. 7  is a diagrammatic illustration of one mode of operation of the optical sensing system of  FIG. 2 . 
         FIG. 8  is a diagrammatic illustration of another operating mode of the optical sensing system of  FIG. 2 . 
         FIG. 9  is a still further mode of operation for the optical sensing system of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     For a better understanding of the invention, one form the invention can take will now be described in detail. Frequent reference will be taken to the appended drawings. Reference numerals or letters will be used to indicate certain parts or locations in the drawings. The same reference numerals or letters will be used to indicate the same parts and locations throughout the drawings unless otherwise indicated. 
     This exemplary embodiment of the invention will be described in the context of implementation with an ice maker/dispenser (indicated generally at reference numeral  30  in  FIG. 1 ) of a side-by-side refrigerator/freezer (indicated generally by reference numeral  10  in  FIG. 1 ). Refrigerator/freezer  10  has a housing  12  that defines, on its left side, a freezer compartment  14  that is accessible by door  18  and, on its right side, a refrigeration compartment  16  accessible by door  20 . 
     Door  18  includes ice/water dispensing station  22 , allowing a user to obtain ice or water through door  18  without opening either door to refrigerator/freezer  10 . Such ice/water dispensers are commonly available in a variety of commercial, residential refrigerator/freezer appliances. One example is Whirlpool® Gold® Models, Whirlpool Corp., Benton Harbor, Mich., USA. 
     In this exemplary embodiment, dispensing station  22  includes a recessed chamber  23  and a floor on which a container such as a glass or cup can be supported. User control panel  24  allows manual selection between modes of operation. In this example, control panel  24  could communicate with a controller  25  (in this example controller  25  could be housed behind user control panel  24 ) which is, in turn, adapted to control a variety of operations of refrigerator/freezer  10 . For example, dispensing levers  26  (for ice) and  28  (for water) could be operatively connected to electrical switches such that when a glass is pushed against either lever, controller  24  would recognize and actuate the appropriate component to provide the selected product (ice or water). 
       FIG. 1  shows in ghost lines the position of an ice maker/dispenser  30  (at least partially built into the back of door  18 ). An ice bucket or container  32  is positioned above ice dispenser/crusher/shaver  34 , which can be actuated by motor  36  that is controlled by controller  24 . Indicated diagrammatically at reference numeral  38 , an ice dispensing chute  38  has an inlet or feed end  40  beneath the ice dispenser  34  and funnels to an exit or dispensing end  42  right above ice dispensing lever  26  at dispensing station  22 . In this manner, ice from ice maker  30  can be accumulated and stored in ice bucket  32 . Upon actuation of motor  36  by controller  24 , ice, in the form selected by the user at control panel  24 , is delivered into the top or inlet end  40  of ice dispensing chute  38  and then falls and is focused by gravity and chute  38  to exit dispensing end  42  of chute  38 , usually into a glass or container pressed against ice dispensing lever  26 . 
     Motor  34  would continue operation and continue to feed ice through chute  38  so long as ice dispensing lever  26  is depressed. The dispensing would cease and operation of motor  34  would cease when the user releases pressure against ice dispensing lever  26 . 
     In this example, the user can select from control panel  24  whether the ice is delivered in cube form as it exists in ice bucket  32 , or whether it is crushed or perhaps shaved by means well known in the art caused by operation of motor  34 . 
     The foregoing is conventional in the art. 
       FIGS. 2 and 3  illustrate an apparatus according to one aspect or exemplary embodiment of the present invention. An optical sensing system (referred to generally as reference numeral  50  in  FIG. 2 ) includes light energy emitter  52  and a complementary light energy detector  54  aligned on opposite sides of ice dispensing chute  38 . Emitter  52  directs a light energy beam across the interior of chute  38 . System  50  is in a normal configuration so long as nothing blocks or attenuates beam  56  below a threshold. However, if an object blocks or sufficiently attenuates beam  56 , optical sensing system  50  issues an output signal to controller  25 . Controller  25  therefore is provided with the information that attenuation of beam  56  exceeds a predetermined calibrated threshold and assumes the presence of an object at that location of chute  38 . According to a programmed algorithm, controller  25  then monitors optical sensing system  50 . If a parameter of the algorithm occurs, controller  25  can automatically disable or discontinue operation of motor  36 . The algorithm will be described in more detail later. 
     It can therefore be seen that the inclusion of optical sensing system  50  provides an automated method of detecting the presence of an object in ice dispensing chute  38  and providing controller  25  with information it can use to determine if an unwanted condition in chute  38  exists, such that automatic shutoff of dispensing motor  36  is indicated. 
       FIGS. 2 and 3  illustrate emitter and detector pair  52 / 54  positioned intermediate between entry opening  40  and exit opening  42  of chute  38 . More particularly, it is indicated as being closer to exit end  42  than entry end  40 . It is to be appreciated, however, that the emitter/detector pair  52 / 54  could be placed anywhere along entry  40 , which defines an ice dispensing pathway. 
       FIGS. 2 and 3  illustrate an alternative placement for the emitter/detector pair. An emitter/detector pair  52 ′/ 54 ′ could be placed outside of chute  38 . In  FIG. 2 , structure (fins  44  and  436 ) extend away from exit opening  42 . Alternative emitter/detector pair  52 ′/ 54 ′ could be placed slightly spaced apart from exit end  42  of chute  38 . It can be appreciated the emitter/detector pair could be placed almost anywhere along the dispensing path, and, as indicated, inside or outside of chute  38 . 
       FIG. 4  shows an alternative embodiment of an ice dispensing chute (see reference numeral  38 ′). Its dispensing or exit end  42 ′ is square-shaped. Emitter  52 /detector  54  can be inside chute  38 . Housing fins  44  and  46  extend from exit end  42 ′. Alternative emitter/detector pair  52 ′/ 54 ′ could be placed so that its beam  56 ′ is actually spaced away from but in front of the exit end  42 ′. The sensor normally will be placed somewhere along or near the dispensing chute or dispensing pathway. A purpose for placing it in the position shown for emitter  52 ′/detector  54 ′ is illustrated at reference numbers L 1  and L 2  in  FIG. 3 . Placement of sensor pair  52 ′/ 54 ′ outside dispensing end  42  of chute  38  would shut motor  36  off sooner upon detection of an unwanted object from the direction of dispensing chamber  23  because it would “see” or sense the object sooner than if sensor pair  52 / 54  (inside chute  38 ) were used. It would start the timing period sooner, because it would trigger when the object is sensed at the lower end of the length L 2 . If pair  52 / 54  were used, it would not trigger until the lower end of distance L 1 . The triggering of the timing of presence of the object would be delayed the time it takes for the object to move the distance L 2  minus L 1 . On the other hand, if sensor pair  52 / 54  inside chute  38  is used, it might be advantageous to place sensor pair  52 / 54  near the exit  42  of chute  38  for detecting ice jams, because it would minimize of amount of ice stuck in the chute and, therefore, minimize the amount of time to clean the jam. The jam would likely start at the narrowest part of the chute (near exit end  42 ) and, thus, placement of sensor  52 / 54  nearer that end  42  would trigger the timing algorithm sooner and likely result in a smaller ice jam before motor  36  is turned off. 
       FIG. 5  shows a block diagram form of an electrical circuit according to this exemplary embodiment. Controller  25  can be any of a variety of commercially available microprocessors or programmable logic controllers (PLCs). Controller  25  can be the programmable device that controls other functions of the refrigerator/freezer  10  or a dedicated controller. 
     For example, not only could emitter and receiver  52  and  54  be operatively connected to controller  25 , ice dispenser lever or switch  26  (as well as user-selectable “cubes”, “crushed” or “shaved” buttons on control panel  24 ) can be inputs to controller  25 . An additional input could be a door open switch  27  which could let controller  25  know if door  18  is open. If so, controller  25  could, in one embodiment, disable or turn off motor  36  regardless of optical sensing system  50 . 
     Transmitter  52  and receiver  54  (or  52 ′ and  54 ′) can be any of a number of commercially available photo emitter/detector pairs. Examples of photo sensors and photo emitter/detector pairs can be found at U.S. Pat. No. 6,314,745. In this embodiment, the pair  52 / 54  would be sealingly positioned along chute  38 . They would not materially obstruct flow of ice in any form along chute  38  but would have clearance to project and receive beam  56  across chute  38  (or beam  56 ′ between items  52 ′ and  54 ′). Electrical connections and wiring from the emitter and receiver to system  50  can be insulated and sealed from moisture. System  50  can include components or circuitry that is compatible and correlated with emitter and receiver  52  and  54  to provide sufficient operating power to emitter  52 . System  50  can be calibrated to trigger when light energy detected at detector  54  is attenuated below a certain threshold level. System  50 , on that trigger, would issue an output signal readable by controller  25  as indicating a sensing of presence of an object between emitter/receiver pair  52 / 54 . 
       FIGS. 6-9  illustrate a method of operation of the apparatus described above. 
     As indicated at  FIG. 6 , when power is provided to refrigerator freezer  10 , controller  25  would check if freezer door  18  is closed (e.g., is switch  27  closed?) (see step  102 ). If not, dispenser motor  36  would be disabled (step  105 ) even if a user pressed ice dispenser switch  26 . 
     However, if switch  27  is closed, indicating door  18  is closed, the program waits until ice dispenser switch  26  is pushed on (step  104 ). If so, dispenser motor  36  is switched on (step  108 ). However, the algorithm  100  monitors light sensor receiver  54 . If a signal from sensor  54  is received corresponding to sensing of the presence of an object (step  110 ), a timer in incremented (step  112 ). If sensor  54  indicates presence of an object for greater than X seconds (step  114 ), dispenser motor  36  is made inoperable or turned off (step  106 ). In this embodiment, X is a value between approximately 1 and 2 seconds. 
     The algorithm will continue to check sensor  54  after an initial indication of the presence of an object, but also continue to operate dispenser motor  36  (steps  108 ,  110 ,  112 , and  114 ) until the X seconds limit is reached. Controller  25  would issue an instruction to deactivate or turn off motor  36  (step  106 ) if T&gt;X is reached. The system assumes an object is in chute  38  and has remained there for over the X seconds. The system assumes this is an unwanted condition and turns motor  36  off so no moving parts in ice dispenser  30  are moving and ice does not continue to be dispensed. 
     On the other hand, note that if there is an initial sensing of presence of an object by sensor  54  (step  110 ), the algorithm increments timer (step  112 ), but if the object discontinues to be sensed before expiration of X seconds, dispenser motor  36  (step  108 ) would continue to operate. There would be no interruption in dispenser motor  36 . The system assumes there is no unwanted condition if the object is not present for greater than X seconds (e.g., 1 to 2 seconds). An example would be falling ice cubes, which might block beam  56 , but not for more than a fraction of a second. 
     Once the sensor beam is indicated as unblocked, the timer would be reset to 0 (step  116 ). The algorithm would continue to operate dispenser motor  36  (step  108 ) until either the ice dispenser switch  26  is released (step  104 ) or the refrigerator door is open (step  102 ). 
     As can be appreciated, algorithm  100  of  FIG. 6  can provide the following function. If the user begins operation of the ice dispenser motor  36  by depression of lever  26 , as illustrated diagrammatically in  FIG. 7 , in normal operation the ice (here ice cubes) would pass through beam  56 . The value of time X would be selected or calibrated so that it is large enough that ice cubes, shaved ice, or crushed ice can pass in pieces in a relatively continuous fashion through beam  56  without creating a false stop. On the other hand, as illustrated in  FIGS. 8 and 9 , a solid, larger individual object (e.g. a knife, fork, spoon— FIG. 8 ) or a collection of non-moving objects (e.g. ice cubes, shaved ice, or crushed ice that is plugged in the ice chute— FIG. 9 ) would trigger a dispenser motor stoppage if its presence is sensed for &gt;X seconds. 
     In the preferred embodiment, time X can be between approximately 1 and 2. This is believed to be adequate to meet the rule. A somewhat continuous flow of ice cubes or even crushed or shaved ice would not be deemed by the system as having a continuous beam blockage for greater than that number of seconds as there would generally be spaces where the light detector  54  would see beam  56  between those pieces. On the other hand, insertion of silverware or a blockage of cubes, crushed ice, or shaved ice, would create normally a continuous block for greater than that number of seconds and cause automatic stoppage of the dispenser motor and continued dispensing of ice. 
     As can be appreciated, the algorithm is intended to differentiate between non-wanted events and wanted events. A wanted event is normal dispension of ice cubes, crushed ice, or shaved ice. An unwanted event can be, for example, the presence of objects such as shown in  FIGS. 8 and 9 . 
     As can be appreciated by those skilled in the art, the foregoing exemplary embodiment is by way of example only and not by way of limitation. 
     For example, a variety of sensors could be used. One example is a capacitive sensor. It could be calibrated to sense the presence of an object, e.g., whether silverware, or clogged ice. Capacitive sensors are well known and commercially available. An example of such technology can be found at U.S. Pat. No. 7,084,643. Other types of sensors could include but are not limited to thermal, electromagnetic, optical, non-ionizing, acoustic, or motion sensors. 
     Variations obvious, after the benefit of this disclosure, to those skilled in the art will be included within the invention.