Abstract:
Popcorn machines having fan assemblies and heat sources are described herein. The fan assemblies and the heat sources can be configured to provide heat to unpopped corn kernels to produce popcorn without the use of cooking oil. The popcorn machines can be configured for commercial use and can be mounted onto support structures that allow operators to rotate the popcorn machines.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application claims the benefit under 35 U.S.C. §119 of U.S. Provisional Patent Application Ser. No. 61/635,805; filed Apr. 19, 2012; and titled “AIR POPCORN POPPER,” the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The following disclosure relates generally to commercial popcorn machines utilizing heated air to pop corn kernels and associated devices and methods. 
       BACKGROUND 
       [0003]    Commercial popcorn vendors typically employ popcorn machines that heat unpopped kernels in a bath of oil. The resulting popcorn can retain a significant portion of the cooking oils, leading to increased oil consumption by consumers who eat popcorn prepared this way. This comes as nutritional experts have increasingly recommended that foods high in fat be reduced or even eliminated from one&#39;s diet. Furthermore, without added oils, popcorn can be a very nutritional food, as it contains relatively high levels of fiber and antioxidants. 
         [0004]    Air popping corn kernels is one method of applying a sufficient amount of heat to unpopped kernels to produce popcorn without the use of added oils. However, typical consumer air popping machines are designed for home use and are not robust or large enough for commercial use (e.g. in a concession stand). Moreover, typical air popping machines lack the ability regulate the heat applied to the corn kernels (e.g., by controlling an amount of current supplied to a heating element, an amount of airflow into the popping machine, etc.) to compensate for variations in, for example, corn kernel varieties and/or ambient conditions. There exists a need for a commercial-grade air popping machine with a temperature and/or airflow intake adjustment capability. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIGS. 1A and 1B  are a front isometric view and a front view, respectively, of a popcorn machine configured in accordance with an embodiment of the present disclosure. 
           [0006]      FIGS. 2A and 2B  are rear isometric views of the popcorn machine of  FIGS. 1A and 1B  configured in accordance with an embodiment of the present disclosure. 
           [0007]      FIG. 3  is a rear isometric view of the popcorn machine of  FIGS. 1A and 1B  with a cover assembly removed for clarity in accordance with an embodiment of the present disclosure. 
           [0008]      FIG. 4A  is a detail front view of the popcorn machine of  FIG. 1B , configured in accordance with an embodiment of the present disclosure. 
           [0009]      FIG. 4B  is a cross-sectional side view of the popcorn machine of  FIG. 4A , configured in accordance with an embodiment of the present disclosure. 
           [0010]      FIG. 5  is an isometric view of a heating element configured in accordance with an embodiment of the present disclosure. 
           [0011]      FIG. 6  is a side view of the popcorn machine of  FIGS. 1A and 1B  illustrating a mode of operation in accordance with an embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    The following disclosure describes various embodiments of air popping popcorn machines and associated devices and methods. Certain details are set forth in the following description and in  FIGS. 1A-6  to provide a thorough understanding of various embodiments of the disclosure. Those of ordinary skill in the relevant art will appreciate, however, that the technology disclosed herein can have additional embodiments that may be practiced without several of the details described below and/or with additional features not described below. In addition, some well-known structures and systems often associated with popcorn machines and methods of making popcorn have not been shown or described in detail below to avoid unnecessarily obscuring the description of the various embodiments of the disclosure. 
         [0013]    The dimensions, angles, features, and other specifications shown in the figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other dimensions, angles, features, and other specifications without departing from the scope of the present disclosure. In the drawings, identical reference numbers identify identical, or at least generally similar, elements. 
         [0014]      FIGS. 1A and 1B  are a front isometric view and a front view, respectively, of a popcorn machine  100  configured in accordance with the present disclosure. Referring to  FIGS. 1A and 1B  together, in the illustrated embodiment, many features of the popcorn machine  100  can be at least generally similar in structure and function to corresponding features to similar popcorn machines described in U.S. application Ser. No. 12/890,370, which is incorporated herein in its entirety by reference. The popcorn machine  100  includes a shell or cabinet  140  that houses an air heating assembly (discussed in more detail below with reference to  FIGS. 4A and 4B ), a support structure or frame  110 , a lid assembly or cover  150 , and an electrical control unit  170 . 
         [0015]    The cabinet  140  can be made from any suitable durable, heat-resistant material (e.g. sheet metal, such as aluminum, stainless steel, etc.) and can include a pair of opposing side walls  141  and  142 , a front wall  143  opposite a removable rear panel  144 , and a top wall  145  opposing a bottom wall  146 . In the illustrated embodiment, the front wall  143  and rear panel  144  have a height H 1  (e.g., 10 inches to 24 inches, or approximately 15 inches) and a width W 1  (e.g., 8 inches to 20 inches, or approximately 12 inches). The side walls  141  and  142  have a length L 1  (e.g., 8 inches to 20 inches, or approximately 12 inches) and height H 1 . The top wall  145  and the bottom wall  146  have a length approximately equal to L 1  and a height approximately equal to H 1 . In other embodiments, however, H 1 , W 1  and L 1  can include any suitable dimension. Moreover, in the illustrated embodiment, the cabinet  140  has a generally rectangular shape, but in other embodiments, the cabinet  140  may have any suitable shape (e.g. a cube, a trapezoidal solid, and/or a sphere). 
         [0016]    The frame  110  is configured to support the cabinet at a height H 2  (e.g., 5 inches to 15 inches, or approximately 8 inches) and includes two U-shaped support structures  114  and  116  fixedly attached to one another by a pair of junction plates  131  and  133 , a pair of side braces  118  and  119 , and a pair of support rails  122  and  124  having a length L 2  (e.g., 10 inches to 30 inches, or approximately 18 inches). A front crossbar  112  and an opposing rear crossbar  113  extend a width W 2  (e.g., 8 inches to 16 inches, or approximately 12 inches) across the support structures  114  and  116 , respectively, to limit rotation of the cabinet  140 . In some embodiments, however, H 2  and W 2  can include any suitable dimension. Moreover, in the illustrated embodiment, the support rails  122  and  124  rest on one or more feet  126 . In other embodiments, the support rails  122  and  124  may rest on, for example, casters, height-adjustable legs, etc. 
         [0017]    The frame  110  is coupled to the cabinet  140  by a pair of operable bearings  130  and  132 . In the illustrated embodiment, the bearings  130  and  132  each include a knob rigidly attached to an end portion (e.g., a threaded rod). The bearings  130  and  132  are inserted through the junction plates  131  and  133 , respectively, into receptacles (e.g. threaded holes, through holes, etc.) in the side walls  141  and  142 , respectively configured to receive the bearings  130  and  132 . An operator may, for example, turn the respective knobs of the bearings  130  and  132  to adjust the degree by which the junction plates  131  and  133 , respectively, press against the respective side walls  141  and  142  to apply friction thereto. Loosening the bearings  130  and  132 , for example, can allow the cabinet  140  to pivot about the bearings  130  and  132  and rotate forward when an operator, for example, pulls downwardly on a handle  134  attached to the side wall  142 . Conversely, tightening the bearings  130  and  132  can press the junction plates  131  and  133  against the side walls  141  and  143 , thereby restricting the ability of the cabinet  140  to rotate. In some embodiments, an operator may loosen and/or tighten the bearings  130  and  132  using, for example, nuts inserted onto the end portions of the bearings  130  and  132 . An L-shaped bracket or bumper  196  is fixedly attached to an underside surface of the bottom wall  146  to limit rotation of the cabinet  140  from the orientation shown in  FIGS. 1A and 1B . The rotational operation of the popcorn machine  100  is discussed in more detail below with reference to  FIG. 6 . 
         [0018]    In the illustrated embodiment of  FIGS. 1A and 1B , the frame  110  can be a base structure supporting the cabinet  140 . However, in other embodiments, the cabinet  140  can be similarly supported from other structures by a frame in other orientations. For example, in some embodiments, the frame  110  can be configured to be mounted, for example, in a housing or cabinet, and/or on one or more side walls or ceiling thereof, to allow the cabinet  140  to rotate during operation as explained above. 
         [0019]    The cover  150  includes a lid  151 , an opening  152 , a pivotable shield  154 , and a duct  158  fixedly attached to the top wall  145  by one or more fasteners  159 . The cover  150  also includes a pair of opposing side panels  155  and  157  and a rear panel  156 . During operation, an operator loads the popcorn machine  100  by pouring unpopped kernels through the opening  152 , the duct  158 , and into a popcorn holding area (discussed in detail below with reference to  FIG. 3 ). The explosive nature of an unpopped kernel becoming a piece of popcorn can cause other unpopped kernels and popcorn to fly wildly and unpredictably. The shield  154 , however, which hangs pendant from the top of the opening  152 , helps to contain the unpopped kernels and popcorn within the popcorn machine  100  during popping operation until a bed of popped kernels expands through the opening  152  and pushes out of the cover  150  past the shield  154 . 
         [0020]    An electrical box or control unit  170  having one or more vents  172  is disposed on the side wall  141 . The control unit  170  can include a control panel  173  having one or more controls  174  (e.g. buttons, switches, knobs, etc.) and one or more displays  178  (e.g., light emitting diodes (LEDs), liquid crystal displays (LCDs), touchscreen displays, etc.). The control unit  170  is electrically coupled to a power input box  180  via a conduit  179 . The power input box  180  can receive external electrical power from a power cord (not shown) plugged into a power source to provide electrical power to the control unit  170 . 
         [0021]    A user can operate various components of the popcorn machine  100  via the control panel  173 . For example, in operation, a user can press a Start Button when the user is ready to begin heating of unpopped corn kernels. Pressing the Start Button can initiate a variety of functions on the popcorn machine  100 . For example, as discussed in more detail with reference to  FIG. 4A , one or more heating elements can be energized and a fan can be activated to begin heating the corn kernels. The control unit  170  can also be configured to automatically complete various operations of the popcorn machine  100 . For example, the control unit  170  can adjust the power to the one or more heating elements after a predetermined amount of time and/or when a predetermined temperature has been reached (e.g., as measured by a thermocouple). The control unit  170  can also, for example, provide an indication on the display  178  that a popping cycle is complete. In some embodiments, for example, the control unit  170  can also adjust a temperature in response to user input. For example, the user can choose a popping cycle and/or temperature based on a list of popcorn varieties that the control unit  170  presents to the user via the display  178 . Based on a selected variety of popcorn and a measured temperature, the control unit  170  can adjust an amount of power to the heating element accordingly to provide sufficient heat to the unpopped kernels. 
         [0022]      FIGS. 2A and 2B  are rear isometric views of the popcorn machine  100  with the rear panel  144  attached and removed, respectively. In  FIG. 2A , the rear panel  144  is removably attached to the cabinet  140  by one or more rear panel fasteners  290  (e.g., screws, clips, bolts, etc.) An air inlet  280  can include, for example, an air intake regulator or rotatable metal disc  281 . The disc  281  includes a plurality of apertures  288  and can rotate about a spindle  282  when force is applied to a handle  284  (e.g., by an operator). A portion of the rear panel behind the disc  281  can have, for example, inlet holes generally similar in size and pattern as the apertures  288 . Rotation of the disc  281  can regulate the amount of air drawn through the inlet  280  into an interior cavity  202  ( FIG. 2B ) of the cabinet  140  by adjusting a percentage of the surface area of the inlet holes of the rear panel open to external airflow. As those of ordinary skill in the art would appreciate, an increase in the open area of the inlet holes is generally proportional to an increase in the amount of heat that the popcorn machine  100  can produce. In some embodiments, for example, air intake regulation may be performed by another device other than the disc  281 . For example, an operable louver, a damper, and/or a slidable shutter may be employed in and/or on the inlet  280  instead of the disc  281 . 
         [0023]    Referring to  FIG. 2B , the cavity  202  is an interior space inside of the cabinet  140  in which an air heating assembly  200  is positioned. As explained in more detail below with reference to  FIGS. 4A and 4B , the air heating assembly  200  includes a motor  208  coupled to a fan (not shown) surrounded by a protective cover or shroud  204  and supported by one or more legs  205 . The air heating assembly  200  is configured to draw in air from the surrounding airspace into the cavity  202  and heat the air to a sufficient temperature to heat unpopped kernels to produce popcorn. 
         [0024]      FIG. 3  is a rear isometric view of the popcorn machine  100  with the cover  150  removed, configured in accordance with an embodiment of the present disclosure. In the illustrated embodiment, a kernel holding area, receptacle or bowl  320  extends downward from an opening  315  in the top wall  145 . The bowl  320  includes a base portion  322  having a plurality of apertures  324  therein. A plurality of holes  330  in the top wall  145  can each receive one of the fasteners  159  to facilitate attachment of the duct  158  to the cabinet  140  ( FIG. 1A ). During operation of the popcorn machine  100 , a user inserts unpopped kernels into the cover  150  (not shown). The unpopped kernels are deposited in and/or on the bowl  320 . The user may then activate the air heating assembly  200  to produce and discharge heated air through the apertures  324  in the bowl  320 , thereby heating the unpopped kernels. If and/or when the air heating assembly  200  produces air having a sufficient temperature (e.g. 400-460 degrees Fahrenheit or 200-240 degrees Celsius), the popcorn machine  100  can heat the unpopped kernels to produce popcorn. The popcorn can then exit the popping machine via the opening  152  in the cover  150  ( FIGS. 1A and 1B ). 
         [0025]      FIG. 4A  is a detail view of the popcorn machine  100 , configured in accordance with an embodiment of the present disclosure.  FIG. 4B  is a cross-sectional side view of  FIG. 4A  along the denoted  4 B line in  FIG. 4A . In the illustrated embodiment of  FIGS. 4A and 4B , the motor  208  is electrically coupled to the control unit  170  via one or more wires  422 , configured to transmit, for example, electrical power and/or control signals. An upper portion of the motor  208  is at least partially surrounded by a circular inner base  426 , which includes a circular lip  427  ( FIG. 4B ) on which the shroud  204  may rest. The inner base  426  further includes a top surface or fan support  429  configured to support an air mover or fan  412  thereon. A spindle  418  rotationally couples the fan  412  to the motor  208 . In the embodiment of  FIG. 4A , the fan  412  is a centrifugal fan having a plurality of blades  414  circumferentially arranged to form a plurality of fan outlets  416 . In other embodiments, however, the fan  412  may be any suitable fan and/or air mover (e.g., an axial fan). 
         [0026]    A heat element  428  is fixedly attached to an upper portion of the shroud  204  and is configured to be placed within the cavity at least proximate to an underside surface of the base portion  322  of the bowl  320  ( FIG. 3 ). As described in more detail below with reference to  FIG. 5 , the heat element  428  can include one or more coils  432  configured produce heat when an electric current is applied therethrough. The heat element  428  can be electrically coupled to the control unit  170  by one or more wires  440 , which can be configured to provide, for example, electrical power and/or control signals to the heat element  428 . 
         [0027]    Upon activation (e.g., when a user depresses a Start button on the control unit  170 ), the control unit  170  can supply electric power to the heat element  428  and the motor  208 . As the motor  208  drives the fan  412  via the spindle  418 , air is drawn through a center opening in the underside of the fan  412  (not shown) and discharged through the fan outlets  416  into a fan cavity  406  surrounded by the shroud  204 . The discharged air flows upwardly in the fan cavity  406  and through the heat element  428 . The heated air further flows into the bowl  320  before continuing out of the popcorn machine  100  through the cover  150 . A wire  442  can electrically couple a thermocouple  444  disposed in and/or on the bowl  320  to the control unit  170 . The thermocouple  444  can provide, for example, temperature data to be shown on display  178 . A protective cover or motor shroud  478  may be employed to at least partially protect and/or insulate the motor  208  from the heat of the incoming recirculated air. 
         [0028]    In some embodiments, for example, the popcorn machine  100  can include a recirculating system  470  configured to recover heat from air escaping the popcorn machine  100  via the cover  150  (e.g., through the use of a heat exchanger) and/or reuse the escaping heated air. Reusing escaping air may offer several advantages, such as, for example, reducing the amount of electrical energy needed to heat air in the popcorn popper and reducing the amount of heated air discharged in the space surrounding the popcorn machine  100 . In the illustrated embodiment of  FIG. 4B , for example, an outlet  471  in a rear portion of the duct  158  can be coupled to the air inlet  280  via a recirculation duct  472 . In some embodiments, a fan assembly  474  including a fan  475  can be disposed at least proximate the inlet  280  to draw escaping air along a path P into the cavity  202  of the cabinet  140  via an outlet  476 . In other embodiments, however, the fan assembly  474  may be installed in another suitable position on the cabinet  140 . The fan assembly  474  can include, for example, one or more filters to remove, for example, byproducts of corn popping operations from the reused air. 
         [0029]    In some other embodiments, however, the recirculation system  470  may include the recirculation duct  472  without the fan assembly  474  and the fan  475 . In one or more of these embodiments, for example, a pressure differential between a first pressure (e.g., an ambient pressure, standard atmospheric pressure, etc.) at the outlet  471  popper and a second pressure (e.g., a negative pressure less than the ambient pressure) at the inlet  280  can cause at least a portion of air escaping the cover  150  to flow into the duct  472  and into the cavity  202  toward the fan  412 . Accordingly a portion of the heated air that may be typically discharged from the machine  100  can be returned to the fan  412 , thereby reclaiming at least a portion of the heat previously produced by, for example, the heat element  428 . 
         [0030]      FIG. 5  is an isometric view of a heating element  500 , configured in accordance with an embodiment of the present disclosure. The heating element  500  includes a metal plate  504  having a grid  506  supporting one or more metal coils  510 . In the illustrated embodiment, the grid  506  includes one or more open areas or gaps  508  through which air may flow during operation of the popcorn machine  100 . The coils  510  may be fixedly attached to the heating element by at least one end by a hook  514  attached at one of a plurality of notches  512  in the metal plate  504 . The coils  510  may also be attached to the metal plate  504  by a fastener  518  (e.g. a screw, a clip, etc.). A lead or wire  540  electrically couples the heating element to the control unit  170  ( FIGS. 1A and 1B ) to provide, for example, electrical power to the heating element  500 . During operation of the popcorn machine  100 , the fan  412  ( FIGS. 4A and 4B ) discharges air, which flows through the heating element  500  and is heated by the coils  510 . If a sufficient amount of heat (e.g. 400-460 degrees Fahrenheit) is produced by the heating element  500 , unpopped kernels in the bowl  320  may begin to pop, thereby producing popcorn. 
         [0031]      FIG. 6  is a side view of the popcorn machine  100  showing rotational operation thereof. The popcorn machine  100  is shown in  FIG. 6  after forward rotation in the direction of arrow A caused by, for example, an operator downwardly pulling the handle  134 . The cover  150  is configured to engage the front crossbar  112  to limit forward rotation of the popcorn machine  100  such that the cover  150  is generally at least a height H above the floor on which the popcorn machine  100  is placed. The operator may wish to rotate the popcorn machine  100  forward as shown in  FIG. 6  to, for example, to empty the popcorn machine  100  of unpopped kernels and/or other byproducts of the corn popping process. The operator can the restore the popcorn machine  100  to its standard upright orientation by pulling upward on the handle  134 , thereby moving the popcorn machine  100  in the direction of arrow B until the bumper  196  engages the rear crossbar  113 . 
         [0032]    As explained above in reference to  FIGS. 1A and 1B , the frame  110  can be a base structure supporting the cabinet  140 . However, in other embodiments, the cabinet  140  can be similarly supported from other structures by a frame in other orientations. For example, in some embodiments, the frame  110  can be configured to be mounted, for example, in a housing or cabinet, and/or on one or more side walls or ceiling thereof, to allow the cabinet  140  to rotate during operation as explained above. 
         [0033]    The foregoing description of embodiments of the invention is not intended to be exhaustive or to limit the disclosed technology to the precise embodiments disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those of ordinary skill in the relevant art will recognize. For example, although certain functions may be described in the present disclosure in a particular order, in alternate embodiments these functions can be performed in a different order or substantially concurrently, without departing from the spirit or scope of the present disclosure. In addition, the teachings of the present disclosure can be applied to other systems, not only the representative popcorn machine devices and methods described herein. Further, various aspects of the invention described herein can be combined to provide yet other embodiments. 
         [0034]    All of the references cited herein are incorporated in their entireties by reference. Accordingly, aspects of the invention can be modified, if necessary or desirable, to employ the systems, functions, and concepts of the cited references to provide yet further embodiments of the disclosure. These and other changes can be made to the invention in light of the above-detailed description. In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above-detailed description explicitly defines such terms. Accordingly, the actual scope of the disclosure encompasses the disclosed embodiments and all equivalent ways of practicing or implementing the disclosure under the claims. 
         [0035]    Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. 
         [0036]    From the foregoing, it will be appreciated that specific embodiments of the disclosed technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the invention. Certain aspects of the disclosure described in the context of particular embodiments may be combined or eliminated in other embodiments. Further, while advantages associated with certain embodiments of the disclosed technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the disclosed technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein. The invention is not limited, except as by the claims.