Abstract:
An oven appliance with one or more features for managing the flow of heated air within the oven cavity is provided. Such features are provided on a floor or wall that is positioned over one or more heating elements. The features are configured to disrupt the formation and/or flow of a high temperature film so that heated air is more uniformly distributed within the oven cavity in order to promote a more uniform cooking of food items therein.

Description:
FIELD OF THE INVENTION 
       [0001]    The subject matter of the present disclosure relates generally to air flow management in the cooking cavity of an oven appliance. 
       BACKGROUND OF THE INVENTION 
       [0002]    An oven appliance typically includes an oven cavity where food items can be placed onto one or more racks for cooking One or more heating sources are provided to provide heat energy into the oven cavity. These heating sources may include e.g., electrically resistant elements, gas burners, and others. The food may receive radiant energy as well as heat energy through conduction and/or convection inside the oven cavity. 
         [0003]    For reasons that include aesthetics and protection of the heating element, modern designs commonly hide or cover heating sources that are located at or below a floor of the cavity. By way of example, referring to the cross-sectional front view of an oven cooking cavity shown in  FIG. 1 , one or more heating elements  50  may be contained within a compartment  52  located beneath the cavity floor or bottom wall  54  of the oven cavity  56 . As such, upon activation of the heating elements  50 , the cavity floor  54  is heated. This heat is then conducted to air in the oven cavity  56 . 
         [0004]    When the oven is operating in non-convective mode, as the temperature of the air near the cavity floor  54  is increased relative to other air in cavity  56 , it becomes buoyant and begins to move upwardly along vertical direction V. Instead of travelling upward to the underside of rack  64  to heat food items  62 , some of this buoyant air will travel as a high temperature boundary layer or film  58  in the direction of arrows F along cavity floor  54  and then along cavity side walls  60 . Upon reaching the top of cavity  66 , this high temperature air will be turned back towards food items  62  on rack  64  and will pool over items  62  as indicated in  FIG. 1  by arrows P. 
         [0005]    As a result of the above-described effect, the food items  62  are prone to top browning due to the pooling of high temperature air above items  62 . This can be undesirable for several reasons. For example, the aesthetics of the foods items  62  may be non-uniform, the top of the food may be cooked or overdone, while the bottom may be undercooked or raw, and other reasons as well. 
         [0006]    Accordingly, an oven appliance that can provide a more uniform cooking of food items is desirable. More particularly, an oven appliance that has features for managing the direction of air flow in the oven so as to promote a more even cooking of food items in the oven cavity would be useful. Such features would be particularly beneficial in an oven appliance that has one or more heating element hidden or covered below a floor or bottom wall of the oven cavity. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0007]    The present invention provides an oven appliance with one or more features for managing the flow of heated air within the oven cavity. Such features are provided on a floor or wall that is positioned over one or more heating elements. The features are configured to disrupt the formation and/or flow of a high temperature film so that heated air is more uniformly distributed within the oven cavity in order to promote a more uniform cooking of food items therein. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
         [0008]    In one exemplary embodiment, the present invention provides an oven appliance that includes an oven cavity for the receipt of food items for cooking A bottom wall defines at least a lower part of the oven cavity. The bottom wall includes at least one connecting portion and at least one air directing portion. The air directing portion includes a surface for directing a flow of heated air upwardly in the oven cavity. A heating source is located below the bottom wall for providing heat energy to the oven cavity. 
         [0009]    In another exemplary embodiment, the present invention provides an oven appliance that includes an oven cavity for the receipt of foods for cooking The oven cavity is defined in part by a cavity floor and a top wall. The cavity floor includes a plurality of air directing portions, each air directing portion including at least one surface projecting upwardly into the oven cavity so as to direct a flow of heated air upwardly into the oven cavity. A heat source is positioned below the cavity floor for providing heat energy to the oven cavity. 
         [0010]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
           [0012]      FIG. 1  provides a cross-sectional view of a conventional oven cavity with a schematic depiction of air movement therein. 
           [0013]      FIG. 2  illustrates a front view of an exemplary embodiment of an oven of the present invention. 
           [0014]      FIG. 3  is a cross-sectional view of an exemplary oven cavity of the present invention with a schematic depiction of air movement therein. 
           [0015]      FIG. 4  is a close-up of a portion of the floor or bottom wall of the exemplary oven cavity of  FIG. 3 . 
           [0016]      FIGS. 5-7  illustrate alternative exemplary embodiments of oven cavities of the present invention where only a lower portion of the oven cavity is shown. 
       
    
    
       [0017]    The same or similar reference numerals appearing the figures may be used to represent the same or similar features. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
         [0019]    Referring to  FIGS. 2 and 3 , an exemplary embodiment of an oven  100  according to the present invention is shown.  FIG. 1  provides a front view of oven  100  while  FIG. 2  provides a front, cross-sectional view of the cooking chamber or oven cavity  156 . Oven  100  includes a door  104  with handle  106  that provides for opening and closing access to oven cavity  156 . A user of the appliance  100  can place a variety of different items  162  to be cooked on one or more racks  164  in oven cavity  156 . A window  110  on door  104  allows the user to view e.g., food items during the cooking process. Insulation and/or ventilation passage ways may be located in the space  168  located between cabinet  170  and walls  160  and  166 . 
         [0020]    Oven cavity  156  is defined in part by a top wall  166 , a pair of opposing side walls  160 , and bottom wall  154 . One or more heating sources  150  are located in a compartment  152  positioned below bottom wall  154 . Heating sources  150  may be electrical resistant elements, gas burners, or other heat sources. Additional heating sources may be located at or behind top wall  166  as well. Upon activation, heating sources  150  provide heat that is transferred to bottom wall  154  and conducted to air in oven cavity  156 . 
         [0021]    Oven  100  includes a user interface  102  having a display  103  positioned on a top panel  114  with a variety of controls  112 . Interface  102  allows the user to select various options for the operation of oven  100  including e.g., temperature, time, and/or various cooking and cleaning cycles. Operation of oven appliance  100  can be regulated by a controller (not shown) that is operatively coupled i.e., in communication with, user interface panel  102 , heating element  150 , and other components of oven  100  as will be further described. 
         [0022]    For example, in response to user manipulation of the user interface panel  102 , the controller can operate heating element  150 . The controller can receive measurements from a temperature sensor (not shown) placed in cooking chamber  156  and e.g., provide a temperature indication to the user with display  103 . The controller can also be provided with other features as will be further described herein. 
         [0023]    By way of example, the controller may include a memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of appliance  100 . The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. 
         [0024]    The controller may be positioned in a variety of locations throughout appliance  100 . In the illustrated embodiment, the controller may be located under or next to the user interface  102  otherwise within top panel  114 . In such an embodiment, input/output (“I/O”) signals are routed between the controller and various operational components of appliance  100  such heating sources  150 , controls  112 , display  103 , sensor(s), alarms, and/or other components as may be provided. In one embodiment, the user interface panel  102  may represent a general purpose I/O (“GPIO”) device or functional block. 
         [0025]    Although shown with touch type controls  112 , it should be understood that controls  112  and the configuration of appliance  100  shown in  FIG. 1  is provided by way of example only. More specifically, user interface  102  may include various input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface  102  may include other display components, such as a digital or analog display device designed to provide operational feedback to a user. The user interface  102  may be in communication with the controller via one or more signal lines or shared communication busses. Also, oven  100  is shown as a wall oven but the present invention could also be used with other appliances such as e.g., a stand-alone oven, an oven with a stove-top, and other configurations as well. 
         [0026]    Referring now to  FIGS. 3 and 4 , once heating sources  150  are activated, heat is transferred to the bottom wall  154  of the oven cavity  156  and then conducted to air in cavity  156 . As the temperature increases, a film or boundary layer  158  of high temperature air is created near the surface  170  ( FIG. 4 ) of bottom wall  154 . Because the air in film  158  is at a higher temperature than other air in oven cavity  156 , it becomes buoyant and will seek to rise along vertical direction V while travelling close to surface  170  as indicated by arrows F. 
         [0027]    Bottom wall  154  includes a plurality of air directing portions  172 , which in  FIGS. 3 and 4  are illustrated as a plurality of dimples  174 . For example, bottom wall  154  can be constructed from a metal sheet into which depressions can be formed to create dimples  174 . Other shapes for air directing portions  172  may be used as well. Air directing portions  172  are spaced apart from each other and located between a plurality of connecting portions  176 . 
         [0028]    For the exemplary embodiment shown, connecting portions  176  of bottom wall  154  are relatively flat or planar while air directing portions  172  project into oven cavity  156  or extend upwardly along vertical direction V into oven cavity  156 . However, other shapes such as e.g., arcuate or curved may be used for connecting portions  176 . Each air directing portion  172  includes surfaces  178  and  180  for directing the flow of air in film  158  upwardly into oven cavity  156  as shown by arrows F. Surfaces  178  and  180  can have a variety of shapes including the convex shape shown as well as concave, arcuate, and others. 
         [0029]    Due to the shape of surfaces  178 , as air in film  158  travels over surface  178  under the effect of buoyancy created by heating with source  150 , the air will move upwardly along vertical direction V upon reaching or nearing the center  182  of air directing portions  172 . Air in film  158  travelling on the opposing surface  180  will behave similarly. 
         [0030]    As a result, high temperature air from film  158  will travel upwardly from air directing portions  172  towards the bottom  184  of food items  162  and rack  164  as indicated by arrows B ( FIG. 3 ). A portion of the surrounding air will also be entrained and directed upwardly as indicated by arrows E. This upwardly moving air will help cook food items  162  and, more particularly, provide heat energy directed at cooking the bottom (the side closest to rack  164 ) of food items  162 . As this air cools, due to buoyancy differences it will fall or travel towards bottom wall  154  as indicated by arrows D ( FIG. 3 ). A portion of high temperature air will still travel towards top wall  166  and be directed downwardly as indicated by arrows P ( FIG. 3 ). This air will also help cook food items  162  and, more particularly, provide heat energy directed at cooking the top of food items  162 . As such, air directing portions  172  work to more uniformly cook food items  162 . 
         [0031]    A variety of shapes, patterns, and other configurations can be used for air directing portions  172  and connecting portions  176 . For example,  FIG. 5  illustrates a cross-sectional view of a portion of an oven cavity  156  in which bottom wall  154  includes a plurality of exemplary air directing portions  172  shaped as dimples  174  spaced between connecting portions  176 . A regular pattern of dimples  174  is shown.  FIG. 6  illustrates another cross-sectional view of a portion of an oven cavity  156  in which bottom wall  154  also includes a plurality of exemplary air directing portions  172  shaped as dimples  174  spaced between connecting portions  176 . In  FIG. 6 , a more irregular pattern of dimples  174  is shown. 
         [0032]      FIG. 7  illustrates a cross-sectional view of a portion of an oven cavity  156  in which bottom wall  154  includes a plurality of exemplary air directing portions  172  shaped as ribs  186  spaced between connecting portions  176 . For this exemplary embodiment, ribs  186  extend longitudinally from the front  188  to the back  190  of oven cavity  156 . However, other orientations may also be used. For example, ribs  186  could extend longitudinally between opposing side walls  160 . Different shapes for ribs  186  may be used as well. 
         [0033]    It should also be understood that while multiple air directing portions  172  are shown, bottom wall  154  of oven cavity  156  could also be equipped with a single portion  172 . By way of example, a single dimple  174  of much larger size could also be centrally positioned on bottom wall  154 . Additionally, to help manage the movement of high temperature air in film  158 , the slope of bottom wall  154  may also be modified. Returning to  FIG. 4 , bottom wall  154  is positioned at an angle θ from the horizontal or lateral direction L. For example, angle θ could be in the range of about 0 to about 5 degrees. Referring to  FIG. 3 , bottom wall  154  could be provided with a downward slope on each side of centerline C/L such that wall  154  slopes downwardly from centerline C/L towards opposing side walls  160 . Due to buoyancy effects, this slope on each side of bottom wall  154  would further facilitate the separation of film  158  from bottom wall  154 . Accordingly, connecting portions  176  do not have to be horizontally oriented and, instead, can also be at various angles θ from the horizontal or lateral direction. In addition, not all of the connecting portions  176  may lie in the same plane. 
         [0034]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.