Abstract:
The present application describes a popcorn maker including a self-regulating heating unit. The self-regulating heating unit provides a regulated heat to the popcorn maker. The self-regulating heating unit can be configured to maintain a predetermined temperature for the popcorn maker. The predetermined temperature can be adjusted to provide appropriate amount of heat to the popcorn maker for popping a maximum number of corn kernels while limiting the heat from causing damage to heating coils and thermoplastic parts of the popcorn maker. The self-regulating heating unit includes a positive temperature coefficient heater.

Description:
PRIORITY CLAIM AND RELATED APPLICATION  
       [0001]    The present application claims priority from U.S. Provisional Application entitled “A Popcorn Maker Employing a Self-Regulating Heating System,” Serial No. 60/416,375, filed Oct. 4, 2002, which is incorporated herein by reference in its entirety for all purposes. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The present invention relates generally to a system and method of making popcorn and, more specifically, to a system and method of making popcorn using a self-regulating heating system.  
         BACKGROUND  
         [0003]    Generally, a popcorn maker includes a chamber for holding popcorn, a heater including a heating coil, and a fan. The chamber is typically included in a cabinet. The cabinet is typically configured using thermoplastic parts. The kernels of corn are placed inside the chamber where the kernels are heated by hot air produced by the heater and the fan. Typically, the heater in the popcorn maker consumes a large amount of power. For example, the heater of a typical 110 volts, 10.9 amperes popcorn maker requires an input power of about 1200 watts. The high power consumption by the heater can significantly increase the internal temperature of the cabinet. For example, if a typical popcorn maker is used for about two hours, then the internal temperature of the cabinet can rise above 100° C. Constant high power consumption over a long period of time can reduce the useable life of heating coils.  
           [0004]    Additionally, high heat can also deform thermoplastic parts of the cabinet, which can cause permanent damage to the popcorn maker.  
         SUMMARY OF THE INVENTION  
         [0005]    In an embodiment, a popcorn maker including a self-regulating heating unit is described. The self-regulating heating unit provides regulated heat to the popcorn maker. The self-regulating heating unit can be configured to maintain a predetermined temperature for the popcorn maker to provide appropriate amount of heat to the popcorn maker for popping maximum number of corn kernels while limiting the heat from causing damage to heating coils and thermoplastic parts of the popcorn maker. According to an embodiment, the self-regulating heating unit includes a Positive Temperature Coefficient (PTC) heater.  
           [0006]    Typically, the PTC heater is configured as a ceramic stone, based on barium titanate. Initially, when voltage is applied across a PTC heater, the resistance of the PTC heater drops, allowing more current to flow through the PTC heater. The PTC heater begins to generate heat. When the heat generated by the PTC heater is sufficient to compensate for the loss of heat to the ambient, the PTC heater reaches a heat equilibrium state with the surrounding. At the heat equilibrium state, the resistance of the PTC heater increases significantly (e.g., by a factor of ten or more) resulting in a significant reduction in the current flow through the PTC heater. When, the ambient temperature decreases, the resistance of the PTC heater also decreases. Thus, drawing more current through the PTC heater resulting in an increase in the amount of heat generated. Similarly, when the ambient temperature increases, the resistance of the PTC heater also increases resulting in a decrease in the amount of heat generated.  
           [0007]    The PTC heater can be configured to regulate heat at any given temperature. The given temperature at which the PTC heater regulates the heat is known as the Curie point of the PTC heater. The PTC heaters are also effective for voltage changes. For example, if the operating voltage of the PTC heater increases, then initially, the PTC heater consumes more power but its temperature also increases rapidly, which stabilizes the current, flowing through the PTC, relatively faster. Unlike traditional wire heaters with ohmic resistance, the performance of the PTC heater is not proportional to the square of the voltage. The PTC heater provides substantially the same wattage output for any given voltage. Therefore, the PTC heaters can be used for any voltage application (e.g., 120V AC, or 240V AC).  
           [0008]    The PTC heater can be an effective low cost solution for applications requiring regulated heat because the PTC heater can provide a highly efficient source of regulated heat in a very small package, which allows the use of smaller enclosures. The PTC heater also provides lower operating costs because the power consumption varies according to the required temperature. Because the PTC heater has self-regulating temperature characteristic, it can be operated without the traditional need of thermostatic control.  
           [0009]    In some embodiments, the self-regulating PTC heater regulates a given temperature for the popcorn maker. The given temperature can be high enough to pop the kernels of corn and low enough to prevent deformation of thermoplastic components of the popcorn maker. For example, in a ceramic chamber, the preset temperature of the PTC heater can be adjusted to be regulated around 290° C. Further, the temperature range for the ceramic surrounding of the PTC heater can be adjusted to be regulated around 200° C. Similarly, various different temperature settings can be used according to the composition of the material used for the PTC heater.  
           [0010]    Also disclosed is a popcorn maker including a heating chamber with a self-regulating heating unit. The self-regulating heating unit includes a PTC heater to provide a regulated heat to the heating chamber. The heating unit is mounted on a vessel for holding corns. The popcorn maker further includes a fan loading system and a cabinet with a conical shaped interior for discharging popped kernels of corns to a container. A lid is provided to cover both the cabinet and the container for preventing the popped kernels of corns from popping out of the device and for guiding the popped kernels of corn into the container. In some variations, the popcorn maker includes a heating chamber without a fan loading system.  
           [0011]    In some embodiments, a method of making popcorn is described. The method includes heating kernels of corn up to a preset temperature using a self-regulating heating system in a vessel of a popcorn maker, popping the kernels of corn, and collecting popped kernels of corn in a container using a conical bowl shaped popcorn guiding means. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 illustrates various components of an exemplary self-regulating heating unit;  
         [0013]    [0013]FIG. 2 illustrates an exemplary assembly of a self-regulating heating unit;  
         [0014]    [0014]FIG. 3 illustrates a bottom view of an exemplary heating chamber of a popcorn maker configured using a self-regulating heating unit;  
         [0015]    [0015]FIG. 4A illustrates an exemplary popcorn maker with a self-regulating heating unit configured using a fan loading system;  
         [0016]    [0016]FIG. 4B illustrates an exemplary air-driving device for a popcorn maker;  
         [0017]    [0017]FIG. 5 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit and a fan loading system;  
         [0018]    [0018]FIG. 6 is a flowchart illustrating an exemplary sequences of steps performed during a process of making popcorn using a popcorn maker with a self-regulating heating unit and a fan loading system;  
         [0019]    [0019]FIG. 7 illustrates a cross sectional view of a popcorn maker with a self-regulating heating unit and a lever loading system;  
         [0020]    [0020]FIG. 8 illustrates a cross sectional view of a popcorn maker with a self-regulating heating unit and a rotor loading system;  
         [0021]    [0021]FIG. 9 illustrates a cross sectional view of a popcorn maker with a self regulating heating unit and a pulley loading system;  
         [0022]    [0022]FIG. 10 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit and a push bar loading system;  
         [0023]    [0023]FIG. 11 illustrates a cross-sectional view of a top cover of the push bar loading unit having an inlet and an inclined plate;  
         [0024]    [0024]FIG. 12 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit and a lever and gear set loading system;  
         [0025]    [0025]FIG. 13 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit and a rotary table loading system;  
         [0026]    [0026]FIG. 14 illustrates a cross-sectional view of a heating chamber of the popcorn maker with the rotary table loading system;  
         [0027]    [0027]FIG. 15 illustrates a pre-heating storage of the rotary table loading system;  
         [0028]    [0028]FIG. 16 illustrates an exemplary rotary table for the rotary table loading system;  
         [0029]    [0029]FIG. 17 illustrates a front view and a back view of an exemplary handling unit for the rotary table loading system; and  
         [0030]    [0030]FIG. 18 illustrates a cross-sectional view of the rotary table loading system.  
     
    
     DETAILED DESCRIPTION  
       [0031]    [0031]FIG. 1 illustrates various components of an exemplary self-regulating heating unit. The self-regulating heating unit includes one or more PTC heaters  1 . The PTC heaters  1  can be configured in various shapes, such as, for example, a circular shape, a square shape, a rectangular shape, or the like. The number of the PTC heaters  1  in the self-regulating heating unit can be adjusted according to the surface area that is to be heated using the self-regulating heating unit and the required temperature. The PTC heaters  1  are coupled to two wires  2  for power supply connection. The wires  2  can be made of high heat resistant material and can be optionally enclosed in high heat resistant insulation tubes  3 .  
         [0032]    The PTC heaters  1  are enclosed in a high heat resistant bag  4 . The high heat resistant bag  4  is then placed inside a hollowed aluminum bracket  5 . The high heat resistant bag  4  provides electrical insulation between the hollowed aluminum bracket  5  and the PTC heaters  1 . The hollowed aluminum bracket  5  has a plurality of holes  6  for fastening. One skilled in the art will appreciate that the hollowed aluminum bracket  5  can be adapted for fastening to a surface to be heated using various fastening means known in the art. The self-regulating heating system is formed using a press tool  8 . The press tool  8  is used to press the top surface of the hollowed aluminum bracket  5  to ensure that the high heat resistant insulation bag  4  is properly positioned inside the hollowed aluminum bracket  5 .  
         [0033]    [0033]FIG. 2 illustrates an exemplary self-regulating heating unit  7  assembled using the individual components illustrated in the FIG. 1.  
         [0034]    [0034]FIG. 3 illustrates a bottom view of an exemplary heating chamber of a popcorn maker configured using a self-regulating heating unit  7 . The self-regulating heating unit  7  can include one or more PTC heaters. The heating chamber includes a vessel  9 . The self-regulating heating unit  7  is mounted on the vessel  9  using screws  11 . The vessel  9  includes one or more vents  10 . The vents  10  allow air to flow in and out of the vessel  9 . The heating chamber can be used in popcorn makers with various loading systems. For example, a fan loading system, a level loading system, a rotor loading system, a pulley loading system, a pushing bar loading system, a lever and gear set loading system, a rotary table loading system, and the like.  
         [0035]    [0035]FIG. 4A illustrates an exemplary popcorn maker with a self-regulating heating unit  7  configured using a fan loading system. The self-regulating heating unit  7  can include one or more PTC heaters. A heating chamber for the exemplary popcorn maker is configured inside a receptacle  13  and under a tube  19 . The heating chamber is supported by at least one but preferably four screw posts  14  for fastening. An air-driving device  18  is located below the heating chamber.  
         [0036]    [0036]FIG. 4B illustrates an exemplary air-driving device  18  for a popcorn maker. In the present example, the air-driving device  18  is a fan that includes an impeller  16  and a motor  17 .  
         [0037]    Referring to FIG. 4A, the impeller  16  is situated inside the receptacle  13 , whereas the motor  17  is located outside the receptacle and mounted to the receptacle  13  with an appropriate fastening means. One skilled in the art will appreciate that the motor can be placed in any convenient location in the heating chamber. The receptacle  13  is sealed with a plurality of orifices  22  at its bottom. In the present example, the receptacle  13  is a cup made of phenol-formaldehyde or other material. The receptacle  13  includes orifices  22  at the bottom allowing air to be driven by the air-driving device  18  into the receptacle  13 . The tube  19  can be made of phenol-formaldehyde or other material. The tube  19  is conjoined with and erected through the receptacle  13  into a cabinet (not shown) forming a passage. The passage is used to deliver the popped kernels of corn into the cabinet.  
         [0038]    [0038]FIG. 5 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit  7  and a fan loading system. The self-regulating heating unit  7  can include one or more PTC heaters. A heating chamber  26  includes a vessel  9  for holding kernels of corn. The self-regulating heating unit  7  is mounted onto the vessel  9  and is configured to provide a regulated heat to the vessel  9 . A fan loading system is located underneath the heating chamber  26 . The fan loading system includes a cabinet  27  with a conical bowl shaped interior for discharging popped kernel of corn into a container  33 . A lid  32  extending from the cabinet to the container is used to prevent the popped corn from popping out of the device as well as guiding the popped kernels of corn to the container. The lid  32  is large enough to cover both the cabinet and the container. A safety switch  34  is configured to engage a protrusion  36  on the container  33 . A receptacle  13  includes the vessel. The container  33  is used to collect popped corn  35  from the heating chamber  26 . The cabinet  27  has a conical-bowl shaped interior conjoined to the tube  19  of the heating chamber  26  thus, forming a passage for discharging popped corn to the container.  
         [0039]    A safety switch  34  is set inside the cabinet  27  and is connected to a power supply. When the container is associated with the heating chamber  26 , a protrusion  36  on the container is used to deactivate the safety switch allowing the current to flow through the heating chamber. However, when the container is taken away from the heating chamber (i.e., the protrusion is not connected to the safety switch), the safety switch is activated thereby ceasing the current flow to the heating chamber. The cabinet contains an aperture  37  at the bottom enabling the safety switch be activated or deactivated by the container. In addition, two switches are employed. One switch is a main switch  30 , and another switch  31  is for the air-driving device. The main switch  30  is connected to the power supply with a power cord  29 . Gaps  38  are provided in the lid  32  for the hot air to escape from the heating cabinet and the heating chamber. It will be appreciated that while the self-regulating heating unit  7  is operating, the fan can be turned off. This increases the heating efficiency by reducing the heat loss and eliminating the noise generated by the fan.  
         [0040]    A user can deposit kernels of corn into the heating chamber by opening the lid  32 . The user can turn-on the power for the self-regulating heating unit  7  to supply heat to the vessel  9 . The air-driving device  18  can be turned-on when substantially all the kernels of corn are popped. The impeller  16  begins to rotate, driving air into the receptacle through the orifices at the bottom of the receptacle. As more air is driven into the receptacle, the air inside the vessel  9  begins to compress. The compressed air then forces itself into the vessel  9  from the vent  10 . When the compressed air travels into the vessel, it pushes the popped kernels of corn out of the heating chamber and the cabinet into the container. When substantially all the popped kernels of corn are pushed into the container, the user can turn the air-driving device off and remove the popped kernels of corn from the container. When the container is taken away, the safety switch is activated thus, disabling the popcorn maker. When the user returns the container to the popcorn maker, the safety switch is deactivated and enables the popcorn maker for the next operation.  
         [0041]    [0041]FIG. 6 is a flowchart illustrating an exemplary sequences of steps performed during a process of making popcorn using a popcorn maker with a self-regulating heating unit and a fan loading system. Initially, the kernels of corn are placed into a heating chamber ( 610 ). The power switch is then turned on ( 620 ). A waiting period is required while the self-regulating heating unit heats the heating chamber ( 630 ). The fan is then turned-on to provide even airflow and direct the popped kernels of corn into a container ( 640 ). The kernels of corn then begin to pop ( 650 ). When substantially all the popped kernels of corn are collected into the container, the fan is then turned off ( 660 ). The popped kernels of corn are then removed from the container ( 670 ).  
         [0042]    [0042]FIG. 7 illustrates a cross sectional view of a popcorn maker with a self-regulating heating unit  701  and a lever loading system. The self-regulating heating unit  701  can include one or more PTC heaters. The popcorn maker includes a heating chamber. The heating chamber includes a vessel  702  for holding kernels of corn. The self-regulating heating unit  701  is mounted on the vessel  702 . The self-regulating heating system  701  is configured to provide a regulated heat to the heating chamber. Further, the popcorn maker includes a lever loading system  703 . The lever loading system  703  includes a lever bar  704 , a pivot bar  705 , a hinge  706  for the pivot bar, a swinging door  707 , and a hinge  708  for the swinging door  707 . The swinging door  707  forms the bottom part of the vessel  702 . The swinging door  707  and the vessel  702  are joined together by the hinge  706  allowing the swinging door  707  to swing outwardly.  
         [0043]    The bottom of the vessel  702  has an inclined surface descending towards the swing door  707 . The lever bar  704  includes an upper vertical section and a lower inclined section. The lever bar  704  is coupled to the swinging door  707  at its lower inclined section end. The pivot bar  705  is attached to the middle of the upper vertical section. The upper section of the lever bar  704  stands upright and is perpendicular to the pivot bar  705 . The pivot bar  705  is placed horizontally across the vessel  702  and is secured to the vessel  702  using the hinge  706 . Furthermore, a passage (not shown) is formed at the end of the inclined bottom of the vessel  702  to allow a user to collect the popped kernels of corn by placing a container below the passage.  
         [0044]    The operating or driving mechanism can be carried out by hand, by gear system, by motor, and the like, or a combination thereof. Due to the gravity, the popped kernels of corn will pileup on the descended side of the bottom of the vessel  702 . The user can open the swinging door  707  by pushing or pulling the lever bar  704 . The swinging door  707  opens outwardly if the lever bar  704  is pushed in a direction away from the swinging door  707 . By opening the swinging door  707 , the popped kernels of corn fall onto the passage (not shown) where the user can collect the popcorn using a container.  
         [0045]    A user can deposit kernels of corn into the vessel  702  and turn on the self-regulating heating units  701  to supply heat to the vessel  702  and the kernels of corn contained therein. When substantially all the kernels of corn are popped, the user can turn-off the self-regulating heating units  701  and push or pull the lever bar in a direction away from the swinging door. The swinging door opens and the popped kernels of corn fall out of the vessel onto the passage. The user can collect the popped corns by placing a container below the passage.  
         [0046]    [0046]FIG. 8 illustrates a cross sectional view of a popcorn maker with a self-regulating heating unit and a rotor loading system. The popcorn maker includes a heating chamber including a vessel  802  for holding kernels of corn. A self-regulating heating unit  801  is mounted on the vessel  802 . The self-regulating heating unit  801  can include one or more PTC heaters. The self-regulating heating unit  801  is configured to provide a regulated heat to the heating chamber. The popcorn maker further includes a rotor loading system  803 . The rotor loading system  803  is associated with the vessel  802 . The popcorn maker further includes a cabinet  804 , at least one supporting bar  805 , and one turning handle (not shown). The heating chamber and the loading system  803  are placed inside the cabinet  804  with the supporting bar  805  traversing through the cabinet  804  and connecting to the turning handle. In the rotor system, the operating or driving mechanism may be carried out by hand, by motor with gear system to drive the support bar, or the like and a combination thereof. The vessel may be placed in a vertical position.  
         [0047]    A user can deposit kernels of corn into the vessel and turn-on the self-regulating heating unit  801  to supply a regulated heat to the vessel  802  and the kernels of corn contained therein. When substantially all of the kernels of corn are popped, the user can then turn-off the self-regulating heating unit  801  and turn the turning handle. By turning the turning handle, the vessel  802  rotates and when the vessel  802  has been rotated to its upright position, the popped kernels of corn fall out of the vessel  802 . The user can then collect the popped kernels of corn using a container.  
         [0048]    [0048]FIG. 9 illustrates a cross sectional view of a popcorn maker with a self-regulating heating unit and a pulley loading system. The popcorn maker includes a heating chamber. The heating chamber includes a vessel  902  for holding kernels of corn. A self-regulating heating unit  901  is mounted on the vessel  902 . The self-regulating heating unit  901  can include one or more PTC heaters. The self-regulating heating unit  901  is configured to provide a regulated heat to the heating chamber. The popcorn maker further includes a pulley loading system  903 . The pulley loading system  903  is associated with the vessel  902  and includes at least two pulleys  904  configured at the top of the vessel  902 , at least one piece of string  905 , and a plate  906 . The self-regulating heating unit  901  is placed underneath the vessel  902 . The vessel  902  can be configured using conductive materials such as, for example, aluminum or the like. A plate  906  is placed inside the vessel with a piece of the string  905  passing over the pulley fastened to the plate  906 . A user can lift the plate  906  by pulling the free end of the string  905 .  
         [0049]    The user can deposit the kernels of corn inside the vessel and turn-on the self-regulating heating unit  901  to supply the regulated heat to the heating chamber. When substantially all of the kernels of corn are popped, the user can turn-off the self-regulating heating unit  901  and pull the free ends of the string  905  to lift the plate  906 . When the plate  906  climbs up to the pulley  904 , the popped kernels of corn falls out of the plate  906  and the user can collect the popped kernels of corn by placing a container at the lower end of the plate  906 .  
         [0050]    [0050]FIG. 10 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit  1001  and a push bar loading system  1003 . The popcorn maker includes a heating chamber. The heating chamber includes a vessel  1002  for storing kernels of corn. The self-regulating heating unit  1001  is mounted on the vessel  1002 . The self-regulating heating unit  1001  can include one or more PTC heaters. The self-regulating heating unit  1001  is configured to provide a regulated heat to the heating chamber. The push bar loading system  1003  includes a top cover  1004 , at least one pushing bar  1005 , at least one moving wall  1006 , at least one swinging door  1007 , and at least two inclined plates  1008 . The vessel  1002  can be configured using thermally conductive material such as, aluminum or the like. The self-regulating heating unit  1001  is placed underneath the vessel  1002 . At least two inclined plates  1008  descending from the bottom of the vessel  1002  are attached thereto on the opposite sides of the vessel  1002  to allow a user to collect the popped kernels of corn when the popped kernels of corn are pushed out of the vessel  1002 .  
         [0051]    A moving wall  1006  and a swinging door  1007  is placed immediately above the moving plates  1008 . The swinging door  1007  is a part of the vessel  1002  and is connected to the vessel  1002  by a hinge  1009 . The hinge  1009  enables the swinging door  1007  to swing outwardly. The moving wall  1006  is also a part of the vessel  1002  and is situated on a side opposite to the swinging door  1007 . The moving wall  1006  has a pushing bar  1005  allowing it to be pushed towards or pulled away from the swinging door. The moving wall has a protrusion to open the swinging door when it is neared the swinging door  1007 . A top cover  1004  is placed above the vessel  1002 .  
         [0052]    [0052]FIG. 11 illustrates a cross-sectional view of a top cover  1004  for a popcorn maker with push bar loading system as illustrated in the FIG. 10. The top cover  1004  includes an inlet  1010  and an inclined plate  1011 . The inlet  1010  allows the kernels of corn to be deposited without opening the cover  1004  and at least one inclined plate  1011  below the inlet  1010  configured to provide a passage for the kernels of corn entering into the vessel  1002  and preventing the kernels of corn from popping out of the vessel  1002 .  
         [0053]    [0053]FIG. 12 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit and a lever and gear set loading system. The popcorn maker includes a heating chamber including a vessel  1202  for holding kernels of corn and a self-regulating heating unit  1201  mounted on the vessel  1202 . The self-regulating heating unit  1201  can include one or more PTC heaters. The self-regulating heating unit  1201  is configured to provide a regulated heat to the heating chamber. The popcorn maker further includes a lever and gear set loading system  1200 . The lever and gears set loading system  1200  includes a container  1203 , at least one base  1204 , at least one post  1205 , at least one set of gears  1206  including at least two gears, at least one lever  1207 , a handle  1208 , and a cabinet  1209 . The post  1205  is standing at the center of the base  1204  with the gears  1206  being mounted at the top. One of the gears is connected to a lever  1207  and the other is connected to a handle  1208  to control the movement of the lever by the handle. The cabinet  1209  occupies one side of the base  1204 . The cabinet  1209  is affixed to the base by at least two screws. The self-regulating heating unit  1201  can be attached to the cabinet  1209  and the vessel  1202  can then be placed on the self-regulating heating unit for providing heat.  
         [0054]    The cabinet  1209  has an open top allowing the vessel  1202  to move in and out of the cabinet  1209 . The vessel  1202  is initially situated on the self-regulating heating unit  1201  with the top part of the vessel  1202  standing out of the cabinet  1209  and connected to the gear  1206  with the lever  1207 . The vessel  1202  can be configured using thermally conductive material such as, aluminum or the like. The vessel  1202  includes a swinging cover  1210 . The swinging cover  1210  is coupled to the vessel  1202  by a hinge  1211 . A container  1203  is placed on the base  1204 .  
         [0055]    After placing the kernels of corn inside the vessel  1202  of the heating chamber, a user can turn-on the self-regulating heating unit. When the kernels of corn contained in the vessel  1002  are popped, the user can push the pushing bar  1005  towards the swinging door  1007  to force it open. When the swinging door  1007  is opened, the popped kernels of corn fall onto the inclined plate  1008  that is below the swinging door  1007 . When the moving wall  1006  reaches the swinging door  1007 , the popped kernels of corn fall onto the inclined plate  1008 . The swinging door  1007  will be closed automatically due to the gravity. When the pushing bar returns to its original position, the remaining popped kernels of corn fall onto the other inclined plate that is on the side where the moving wall was originally situated where they can be collected by the user.  
         [0056]    [0056]FIG. 13 illustrates a cross-sectional view of a popcorn maker with a self-regulating heating unit  1301  and a rotary table loading system. The popcorn maker includes a heating chamber  1300 . The heating chamber  1300  includes a vessel  1302  for holding kernels of corn. The self-regulating heating unit  1301  is mounted on the vessel  1302 . The self-regulating heating unit  1301  can include one or more PTC heaters. The self-regulating heating unit  1301  is configured to provide a regulated heat to the heating chamber  1300 . The popcorn maker further includes a rotary table loading system  1303  and a pre-heating storage unit  1304 , a clear cabinet  1305 , a power switch  1311 , and a power cord  1312 . The rotary table loading system  1303  includes a foundation  1306 , at least one handle unit  1307 , a rotary table  1308 , and an outlet device  1310 .  
         [0057]    [0057]FIG. 14 illustrates a cross-sectional view of a heating chamber  1300  of the popcorn maker with the rotary table loading system  1303  illustrated in the FIG. 13. The heating chamber  1300  includes an outer case  1313 , a base  1314 , an upper cabinet  1315 , a lower cabinet  1316 , at least one cross-shaped metal plate  1317 , at least one or preferably four spring washer  1318 , the vessel  1302 , and the self-regulating heating unit  1301 . The self-regulating heating unit  1301  is fastened to the vessel  1302  using at least two machine screws  1319  together with nuts  1320 . One skilled in the art will appreciate that the self-regulating heating unit  1301  can be fastened to the vessel  1302  using any fastening means known in the art. The self-regulating heating unit  1301  is preferably placed at the center of the heating chamber  1300  and is surrounded by the upper chamber  1315  and the lower chamber  1316 . The upper chamber  1315  and the lower chamber  1316  are joined together by at least one screw  1318  and the same number of nuts  1320 .  
         [0058]    Each of the outer case  1313  and the upper cabinet  1315  has an opening that is of the same size as the vessel  1302  to allow the kernels of corn to pop out of the heating chamber. At least one cross-shaped metal plates  1317  is employed therein to support the self-regulating heating unit  1301  on the lower cabinet  1316 . The cross-shaped metal plate  1317  is secured at the center of the lower cabinet with at least one self-tapping screw  1321  or the like. The upper cabinet  1315  and lower cabinet  1316  are joined together by at least one, but preferably four, machine screws with spring washers  1318 . The outer case  1313  and the lower cabinet  1316  are both fastened to the base  1314  using at least one, but preferably eight self-tapping screws  1321  or the like. Each of the lower cabinet  1316  and the outer case  1313  has a hole  1322  allowing the power cord of the self-regulating heating unit  1301  to be connected to a power supply (not shown).  
         [0059]    [0059]FIG. 15 illustrates a pre-heating storage of the rotary table loading system  1303  described in the FIG. 13. The pre-heating storage unit  1304  is configured to contain the kernels of corn and allow the kernels of corn to be deposited onto the heating chamber  1300  and particularly, into the vessel  1302 . The pre-heating storage unit includes a knob  1323 , a spring  1324 , a tube  1325 , a lid  1326 , a cup  1327 , a shaft  1328 , and a cap  1329 . The cup  1327  is open-ended at the top and the bottom. The lid  1326  covers the top of the cup  1327 . The cap  1329  covers the bottom of the cup  1327 . The lid  1326  has at least one opening  1330  to allow the kernels of corn to be deposited into the cup  1327  and at least one hole at its center for a shaft to be traversed. Immediately above the center of the lid  1326  is the spring  1324  surrounded by the tube  1325  for aesthetic. The tube  1325  can be made using elastic material or the like. The knob  1323  is attached to the shaft  1328  directly above the tube  1325  and the spring  1324 . The knob  1323  is connected to the cap  1329  by a shaft  1328  through the hole at the center of the lid  1326 . The shaft  1328  is secured to the cap  1329  by at least one machine screw  1331 .  
         [0060]    [0060]FIG. 16 illustrates an exemplary rotary table for a rotary table loading system  1308 . The rotary table  1332  includes an annulus having an inclined surface descending from its center with at least one slot  1333  and at least one rib  1334  being distributed thereon. The center of the rotary table  1308  has an opening, which is equal to or slightly greater than the outer case  1313  in the heating chamber to allow the popped kernels of corn to “pop” out of the heating chamber onto the rotary table  1332 . The inclined surface provides a slope so that the popped kernels of corn can move towards the end of the surface by gravitational force and pile up at the end. The slots  1333  allow the hot air from the heating chamber to escape into the clear cabinet  1305  so as to maintain the temperature of the popped corns therein and at the same time reduce the temperature of the heating chamber  1300 . This prevents the hot air from accumulating inside the heating chamber  1300 . The rib  1334  assists in loading the popped kernels of corn to the outlet (not shown) of the rotary loading system  1308 . Along the lower end of the rotary table is a set of toothed wheels  1335 . The size of the tooth on the toothed wheels matches that of a gear in the handle unit (not shown).  
         [0061]    [0061]FIG. 17 illustrates a front view and a back view of an exemplary handle unit for the rotary table loading system. The rotary table loading system includes a handle unit  1307 . The handle unit  1307  includes a handle frame  1336 , a knob  1337 , at least one gear  1338 , and a sound plate  1339 . The frame  1336  includes at least one protrusion  1340  and  1341  placed on each side. The protrusion  1340  on the outer side allows a knob  1337  to be attached to the handle frame  1336  with a screw  1342 . A cover plate  1343  is employed to cover the screw after the screw is inserted into the protrusion  1340  of the handle frame through the knob  1337 . On the inner side of the handle frame  1336 , a gear  1338  is put around the protrusion  1341  and is secured by a screw  1344 . The protrusion  1341  on the inner side of the handle frame  1336  is in the shape of a cross. A sound plate  1339  is posed directly below the protrusion on the inner side of the handle frame  1336  and stands upright with its apex just reaching or slightly above the lower side of the protrusion  1341 . When the handle unit  1307  rotates and so does the handle frame  1336  and the protrusion  1341  on the inner side of the handle frame, the sound plate  1339  generates a sound for example, a “click” sound or the like.  
         [0062]    [0062]FIG. 18 illustrates a cross-sectional view of a popcorn maker with a rotary table loading system. The handle unit  1307  is mounted on the foundation  1306  and the rotary table  1308 . The handle unit  1307  is mounted on the foundation  1306  with the protrusion  1341  on the inner side of the handle frame  1336  passing through one side of the foundation  1306  to the rotary table  1308 . A sound plate  1339  stands upright with its apex just reaching or slightly above the lower side of the protrusion. The gear  1338  associated with the handle unit  1336  is fastened on toothed wheel  1335  on the lower end of the rotary table. Because the size of the teeth on the gear and that of the toothed wheel are well matched, when the user turns the handle unit  1307  and thus the gear therein, the rotary table is rotated accordingly and the sound plates produces a sound such as, a “click” sound.  
         [0063]    The heating chamber  1300  rests on the foundation  1306  and is supported by at least one screw post  1344 . The screw post  1344  and the base  1314  of the heating chamber are affixed together by at least one screw  1345 . The foundation  1306  contains at least one hole  1346  enabling the power cord  1312  of the self-regulating heating unit to be connected to a power supply (not shown). The rotary table  1308  is placed directly above the heating chamber  1300  with the outer case  1313  and the upper cabinet  1315  standing partially out of the rotary table  1308  through the concentric hole of the rotary table. The rotary table is supported by a support slot  1347  from the clear cabinet  1305  and a gear  1338  of the handling unit  1307 . A clear cabinet covers the heating chamber  1300  and the foundation  1306 .  
         [0064]    A pre-heating storage unit (not shown) is situated at the top of the clear cabinet. Alongside the foundation  1306  are the handling unit  1307  and an outlet device  1310 . Although it is shown that the handling unit and the outlet device are situated opposite to each other, they can be posed at any position along the foundation  1306 . The outlet device  1310  includes at least one slot (not shown) on one side of the foundation and a swinging door  1348 . The swinging door  1348  covers the slots and forms a part of the foundation  1306 . The swinging door  1348  is secured to the foundation  1306  by a hinge  1349  enabling the door to swing outwardly. When the swinging door is opened, a passage for the popped kernels of corn is formed and the popped kernel of corn drop out of the heating chamber from the slots. The size of the slots is large enough to allow the popped kernels of corn to pass through the slots yet small enough to prevent anything such as, a child&#39;s finger to enter into the heating chamber.  
         [0065]    Referring to FIGS.  13 - 18 , a user can deposit the kernels of corn in the storage unit via the opening. The pre-heating storage unit is held directly above the heating chamber unit so that the user can deposit the kernels of corn into the heating chamber by simply pushing the knob downwards to force open the cap at the bottom. The kernels of corn contained therein fall onto the heating chamber. When the knob is released, it returns to its original position due to the elastic force from the spring and thus, the cap closes. The user can turn-on the self-regulating heating unit to supply heat to the heating chamber. When substantially all the kernels of corn are popped onto the rotary table, the user can turn-off the self-regulating heating unit. The rotary table has an inclined surface descending from the center towards the ends. The inclined surface enables the popped kernels of corn to pile up along the ends. The user can collect the popped kernels of corn by opening the swinging door of the outlet device. When the swinging door is opened, it forms a passage. Due to the inclined surface of the rotary table and the gravitational force, the popped kernels of corn fall out of the rotary table onto the passage. The user can rotate the rotary table using the handling unit to ensure that substantially all the popped kernels of corn on the rotary table fall out of the device through the outlet.  
         [0066]    The self-regulating heating unit can provide a regulated heat to control the temperature of the cabinet. The temperature of the cabinet can be kept below 100° C., preferably about 60° C., and more preferably below 55° C. The self-regulating heating unit also provides fast heat-up/cool-down for the heating chamber. The self-regulating heating unit has an intrinsic cutoff temperature that is high enough to pop the kernels of corn and low enough to prevent deterioration of any component of the popcorn maker. The power consumption and heat output is relatively low. The self-regulating heating unit replaces heating coils and open fire system required in conventional popcorn makers. The present invention can be produced economically, in a more compact size.  
         [0067]    Realizations in accordance with the present invention have been described in the context of particular embodiments. These embodiments are meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances may be provided for components described herein as a single instance. Boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of claims that follow. Finally, structures and functionality presented as discrete components in the exemplary configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of the invention as defined in the claims that follow.  
         [0068]    The section headings in this application are provided for consistency with the parts of an application suggested under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any patent claims that may issue from this application. Specifically and by way of example, although the headings refer to a “Field of the Invention,” the claims should not be limited by the language chosen under this heading to describe the so-called field of the invention. Further, a description of a technology in the “Description of Related Art” is not be construed as an admission that technology is prior art to the present application. Neither is the “Summary of the Invention” to be considered as a characterization of the invention(s) set forth in the claims to this application. Further, the reference in these headings to “Invention” in the singular should not be used to argue that there is a single point of novelty claimed in this application. Multiple inventions may be set forth according to the limitations of the multiple claims associated with this patent specification, and the claims accordingly define the invention(s) that are protected thereby. In all instances, the scope of the claims shall be considered on their own merits in light of the specification but should not be constrained by the headings included in this application.