Abstract:
A cooking appliance includes a grilling grate supported directly above at least one heating element and situated adjacent to a downdraft grill. The grilling grate includes structure to effectively shield the heating element(s) from an air flow generated during operation of the downdraft system. More specifically, the grilling grate includes a grilling surface on an upper side, and a plurality of conductive heat members on a lower side. The conductive heat members have side portions which extend about the heating element in order to cloak the heating element from the effects of the airflow produced by the downdraft system thereby providing a more efficient means of energy transfer to the grilling surface.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention pertains to the art of cooking appliances and, more particularly, to a cooking appliance including a downdraft system and a grilling unit including a grilling surface and a plurality of support members which serve to shield an electric resistive-type heating element from airflow currents created by operation of the downdraft system.  
           [0003]    2. Discussion of the Prior Art  
           [0004]    In the art of cooking appliances, it is known to utilize a grilling surface supported above heating elements for the purpose of cooking various foodstuffs, for example: steak, fish, vegetables and the like. Over the course of time, several problems have been identified in connection with the operation of such grills. For instance, fats and oils dripping from the cooked foods can damage the heating coil and, in addition, produce quantities of smoke, grease and other airborne by-products which contaminate the cooking area.  
           [0005]    The need to protect the heating elements in an electric grill is recognized in the prior art, at least with respect to portable electric grilling units. Inventors have developed several techniques to address these problems. For example, U.S. Reissue Pat. No. 36,464 addresses certain problems associated with fats and oils dripping onto the burner elements in portable grills. The griller is described as having a channel formed on the underside of a grill member to shield lower heating elements from dripping fat and liquids. Although this design adequately addresses the problems associated with falling debris, it fails to solve the additional problems associated with grilling in combination with a downdraft system, e.g., the production of airborne by-products associated with the grilling process, and the resulting efficiency loss created by the generation of cooling airflows.  
           [0006]    All grilling surfaces inherently produce airborne by-products resulting from the combustion of food components. This problem is exacerbated when the grills are used indoors. For instance, airborne by-products are irritants and warrant removal from the cooking area. For that reason, downdraft fans are provided to create an air flow whereby air is drawn past the grill and ducted away from the cooking area. However, because the grill is preferably heated, at least in part, through conductive energy provided by the heating coils, the air flow created by the downdraft fans reduces the cooking efficiency, results in increased energy consumption and causes the food to cook unevenly.  
           [0007]    The airflow which draws away the airborne by-products, also passes the exposed surfaces of the heating elements, thereby reducing their temperature. It is therefore desirable to shield the heating elements from the airflow, while maintaining contact between the heating elements and the grilling surface. Accordingly, there still exists a need in the art of cooking appliances for a grilling system which protects the heating elements from the efficiency losses caused by convective cooling, while also protecting the heating elements from dripping by-products.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention is directed to a grilling grate system for cooking appliances incorporating a downdraft fan unit, wherein the grilling grate system is configured to effectively shield one or more heating elements from the air flow generated by the downdraft fan unit. More particularly, the cooking appliance is provided with a downdraft grill system including a grilling grate defining a cooking zone. The grilling grate includes an upper portion and a lower portion. The upper portion is defined by a plurality of support members that define a grilling surface and the lower portion is formed with a plurality of conductive heat members. The conductive heat members have elongated side portions which extend past leg portions of the heating element(s) in order to cloak the heating element(s) and minimize the effects of the airflow generated by the downdraft fan unit. With this arrangement, the conductive heat members are able to provide a more efficient means of energy transfer to the grilling surface.  
           [0009]    During a cooking operation, air is drawn through slots defined in the grilling surface, whereby smoke and other air laden cooking by-products are conducted away from the cooking zone. As air is drawn through the slots, it is forced passed the leg portions of the electric heating element(s). In the past, the airflow passing the heating element(s) would lower the surface temperature of the heating element(s) through convective cooling, thereby resulting in reduced cooking efficiency. The cloaking grill grate of the present invention effectively increases the heating efficiency of the cooktop grill by protecting the electric heating element(s) from the detrimental effects of the cooling airflow produced by the downdraft system. Through the use of the present invention, as described herein, the air currents generated by the downdraft fan unit are directed around the elongated side portions of the conductive heat members, such that the side portions function to shield or cloak the leg portions of the heating element(s) from contact with the airflow, thereby minimizing the cooling effect produced by the airflow. Concurrently, the heating element(s) is protected from liquid by-products dripping thereon.  
           [0010]    Additional objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment, when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of a preferred embodiment of the cooking appliance incorporating a heater cloaking grill grate system constructed in accordance with the present invention;  
         [0012]    [0012]FIG. 2 is an enlarged cross-sectional view of the grill grate of FIG. 1; and  
         [0013]    [0013]FIG. 3 is an enlarged, cross-sectional side view of a section of the grill grate shown extending about a leg portion of a heating element of the cooking appliance. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]    With initial reference to FIG. 1, a cooking appliance, generally indicated at  2 , is shown to take the form of a range. Cooking appliance  2  includes a cabinet  6  having opposing side panels  8 , a cooktop  9 , a rear panel (not shown) and a front panel  11 . An upper portion of front panel  11  defines a face  12  that includes a plurality of controls as will be more fully described below. Arranged below upper front face  12  is an oven door  16  having a handle  18  and a window  20 . In a manner known in the art, door  16  can be pivoted to access an interior oven cavity (not separately labeled) of cooking appliance  2 . Also, as shown, cooking appliance  2  includes a lower drawer  24  for use in storing pots, pans and the like.  
         [0015]    In the embodiment illustrated, upper front face  12  is provided with a central oven control section  28  that includes a display  29  and various sets of control buttons  31 - 33 . Although not considered part of the present invention, for the sake of completeness, control button set  31  is preferably utilized to establish a desired mode of operation for the oven of cooking appliance  2 , control button set  32  represents a numeric pad including a cancel button, and control button set  33  represents program buttons for establishing desired cook times, clock settings and the like. In addition, upper front face  12  is provided with a plurality of element control knobs  37 - 40 . In this embodiment, element control knobs  37  and  38  are utilized to control the operation of upper heating elements  43  and  44  respectively. In the embodiment shown, upper heating elements  43  and  44  are integrated into a first cartridge  46  which is adapted to be selectively placed within a first opening  47  formed in cooktop  9 . As will be detailed more fully below, element control knobs  39  and  40  are utilized to control the operation of a grilling unit  49  located within a second opening  50  also formed in cooktop  9  as will be more fully described below.  
         [0016]    Also illustrated in accordance with the preferred embodiment of the invention is a downdraft system which is generally indicated at  52  and arranged between cartridge  46  and grilling unit  49 . Downdraft system  52  includes a grill  55  having a plurality of openings  60 . In a manner generally known in the art, downdraft system  52  is used in combination with a blower element (not shown) to exhaust smoke and other air laden by-products when cooking on cooktop  9 . The overall downdraft system  52  can be controlled through one of the buttons in central oven control section  28 , or automatically whenever any one of control knobs  37 - 40  are placed in an activated state. In general, with the exception of the construction of the grilling unit  49  and its manner of operation in connection with downdraft system  52 , the construction and operation of cooking appliance  2  is known in the art. Therefore, additional details of the general construction and operation of cooking appliance  2  will not be provided here. Instead, reference will now be made specifically to FIGS. 2 and 3 in describing a preferred construction and operation of grilling unit  49 .  
         [0017]    As shown, grilling unit  49  is defined by a base portion  65  located within second opening  50 . Situated upon base portion  65  are a plurality of laterally extending and fore-to-aft spaced support rails  85 , each having an upper cross portion  86  and spaced support leg portions  87 . The upper cross portion  86  of each support member  85  includes a plurality of arcuate notches  89  adapted to receive portion of a respective heating element  90  of grilling unit  48 . In the most preferred embodiment, two heating elements  90 , each preferably constituted by an electric, sheathed, resistance-type element having a set of electrical connecting prongs (not shown) adapted to engage a receptacle (also not shown) provided within second opening  50 . Of course, it should be recognized that an enlarged, single heating element could be equally employed.  
         [0018]    As shown, each heating element  90  extends in a generally serpentine path, with a plurality of generally parallel leg portions  92  and curved leg portions  93  adapted to act as a conductive heat source for a grill member in the form of a grate  105 . As will be discussed more fully below, grill member  105  is defined by a plurality of support members  112 , separated by a series of openings or slots  113  and joined by a peripheral portion  114 . As shown, peripheral portion  114  includes an outermost lip  115  adapted to engage cooktop  9 .  
         [0019]    As shown in FIG. 3, each support member  112  is defined by an upper portion  118 , opposing sloped portions  120 , and side portions  125  having spaced lower extension portions  126 . With this construction, each support member  112  defines an elongated channel  128  that preferably traverses a major portion of the length of support member  112  and is adapted to receive one of the plurality of leg portions  92  of heating element  90 . More specifically, each leg portion  92  fits into a respective channel  128  such that only a small air gap  129 , preferably in the order of {fraction (1/16)}″ or less, is defined between the heating element  90  and channel  128  as shown. Alternatively, air gap  129  can be avoided, with heating element  90  directly abutting the entire channel  128 .  
         [0020]    In accordance with the most preferred form of the invention, each extension portion  126  is adapted to extend substantially past the midpoint of the cross-sectional area of leg portion  90 , i.e., a substantial distance below a central, longitudinal axis of leg portion  90 . Although the lower extension portion  126  is generally shown as a semi-hemispherical channel, it is further contemplated that the channel can take whatever shape is required to follow an outer contour of any particularly shaped heating element. Of course, at this point, it should be realized that accommodations must be made for curved leg portions  93  of each heating element  90 . In accordance with the invention, each support member  112  is void of any lower extension portions  126  at curved leg portions  93  of heating element  90 . This configuration is not considered problematic as substantially all of the air developed by downdraft system  52  is generated at a position spaced from the fore-to-aft portions of heating element  90 . In addition, it is commonplace to cook food items in a more central location. However, it is also contemplated that support elements  112  can take a fully conforming serpentine path as well.  
         [0021]    During use, each heating element  90  is energized via an associated control knob  39 ,  40  to cause electricity to flow through the resistive coils causing the temperature of the heating element  90  to rise substantially. The resultant heat energy is transmitted from heating element  90 , via air gap  129 , to support member  112  and conducted to upper portion  118  thereof. Once the temperature of upper portion  118  has reached its desired level, a cooking process is initiated by placing an item of food, either directly or upon another cooking surface, onto upper portion  118  of grill member  105 .  
         [0022]    Once the cooking process starts, airborne by-products will inherently begin to emanate from the food item placed upon grill member  105 . To mitigate the impact of the airborne by-products on the surrounding area, the downdraft system  52  is operated, either separately or as part of the grill control as discussed above, whereby an airflow is created which circulates past heating element  90  below grill member  105 , up through slots  113 , over grill member  105  and into openings  60  of grill  55 . The airborne by-products will inherently be drawn away with this air flow. As should be readily understood, openings  60  lead to an exhaust plenum (not shown).  
         [0023]    While the downdraft system  52  does provide the benefit of removing harmful smoke and other airborne by-products from the cooking area, this benefit is not derived without cost. More specifically, the airflow created by the downdraft system  52  has the tendency to lower the efficiency of grilling unit  49  by lowering the temperature of both grill member  105  and heating element  90 . This efficiency loss is minimized by the application of the current invention. As described above, heating element  90  resides with channel  128  formed on the conducting, lower extension portions  126  of support members  112 . As the air is drawn past heating element  90 , lower extension portions  126  surround and cloak leg portions  92  of heating element  90  thereby minimizing their exposure to the cooling effects of the airflow, particularly given that the airflow is directed laterally, substantially perpendicular to cloaking or extension portions  126  and then up through openings  60  which are defined between respective side portions  125 . In this manner, the heating efficiency of heating element  90  is increased, resulting in lower energy consumption and faster cooking times. In addition, support members  112  further prevent liquid by-products from flowing through slots  113  and onto heating element  90 , which would substantially increase at least the amount of smoke developed.  
         [0024]    Although described with respect to a preferred embodiment of the present invention, it should be readily apparent that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For example, although grilling unit  49  is described as a replaceable cartridge, it is understood that grilling unit  49  may be provided as an integral part of cooktop  9 . In general, the invention is only intended to be limited by the scope of the following claims.