Abstract:
A cooktop appliance includes a gas burner assembly positioned on a panel of the cooktop appliance and a grate that suspends the burner in air above the panel. The gas burner assembly includes an inwardly directed burner that provides more uniform heating of a cooking utensil supported on the grate. In addition, a large aperture extends through the center of the burner to ensure proper delivery of air to mix with fuel for combustion. The resulting cooktop appliance provides improved heating over the entire cooking utensil and simplifies the cleaning process.

Description:
FIELD OF THE INVENTION 
       [0001]    The present subject matter relates generally to cooktop appliances, such as a gas cooktop appliance with gas burner assemblies. 
       BACKGROUND OF THE INVENTION 
       [0002]    Generally, gas cooktop appliances include a plurality of gas burners mounted to a top surface of the appliance. Conventionally, these burners have had flames that travel radially outward from the gas burner. While this approach works well to heat a majority of the cooking utensil surface, the center most portion of the cooking utensil does not get the same heat transfer rates as the perimeter and uneven heating results. 
         [0003]    To overcome this inherent uneven heating, inwardly directed burners are available which direct the flames radially inward from a burner having an open center. In this manner, inwardly directed burners heat a cooking utensil more uniformly by directing flames such that they converge at the center of the cooking utensil before traveling back out the sides of the cooking utensil in a radial fashion. In order to provide sufficient secondary air to ensure the fuel burns cleanly, current designs require that these inwardly directed burners have large, open centers on the top surface beneath the burners. 
         [0004]    However, during use of the cooktop, spills and overflows can easily pass down the open center of the burners into the interior of the cooktop. This can lead to food particles accumulating both on the top surface of the cooktop beneath the gas burners as well as in the interior. Due to the proximity of the burners to the top surfaces, the accumulated food particles have a tendency to burn onto the cooktop and can be difficult to clean. Significant disassembly is often needed to clean the spills beneath the gas burners. In addition, gas burners that are fastened to the cooktops generally include cracks at assembly interfaces and include holes, supporting geometry, and fasteners that tend to accumulate food particles and are difficult to clean around. Thus, a serious drawback to this design is the ability to clean spills and users frequently cite difficulty cleaning beneath the gas burners as a complaint about modern cooktops. 
         [0005]    Accordingly, a cooktop appliance with features for facilitating cleaning below a burner of the cooktop appliance would be useful. In addition, a cooktop appliance having an inwardly directed burner with features for ensuring proper delivery of the secondary air to the burner and improved heating of the cooktop utensil would be particularly beneficial. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0006]    The present subject matter provides a cooktop appliance. The cooktop appliance includes a gas burner assembly positioned on a panel of the cooktop appliance and a grate that suspends the burner in air above the panel. The gas burner assembly includes an inwardly directed burner that provides more uniform heating of a cooking utensil supported on the grate. In addition, a large aperture extends through the center of the burner to ensure proper delivery of air to mix with fuel for combustion. The resulting cooktop appliance provides improved heating over the entire cooking utensil and simplifies the cleaning process. 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. 
         [0007]    In a first exemplary embodiment, a gas burner assembly for a cooktop appliance is provided. The gas burner assembly includes a grate configured for supporting a cooking utensil above a panel of the cooktop appliance. A cap is integrally formed with the grate and defines an air passage extending vertically through a center of the cap. A base is mounted to the cap such that the cap and the base define a fuel chamber, the base further defining a circumferential wall defining a plurality of flame ports, the plurality of flame ports opening into the air passage. 
         [0008]    In a second exemplary embodiment, a cooktop appliance is provided. The cooktop appliance includes a panel having a top surface and a bottom surface. A fuel orifice is mounted to the panel adjacent the bottom surface of the panel and a gas burner assembly is positioned on the panel at the top surface of the panel. The gas burner assembly includes a grate configured for supporting a cooking utensil above the panel of the cooktop appliance. The gas burner assembly further includes a burner that is fixed to the grate, the burner defining an air passage extending vertically through a center of the burner. The burner further defines a fuel chamber and a circumferential wall defining a plurality of flame ports, the plurality of flame ports opening into the air passage. 
         [0009]    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 
         [0010]    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. 
           [0011]      FIG. 1  provides a top, perspective view of a cooktop appliance according to an exemplary embodiment of the present subject matter. 
           [0012]      FIG. 2  provides another top, perspective view of the exemplary cooktop appliance of  FIG. 1  with a gas burner assembly of the exemplary cooktop appliance shown removed from a panel of the exemplary cooktop appliance. 
           [0013]      FIG. 3  provides a front, section view of the exemplary cooktop appliance of  FIG. 1 . 
           [0014]      FIG. 4  provides a section view of the gas burner assembly of the exemplary cooktop appliance of  FIG. 1 . 
           [0015]      FIG. 5  provides an exploded, top perspective view of the gas burner assembly of the exemplary cooktop appliance of  FIG. 1 . 
           [0016]      FIG. 6  provides a bottom, perspective view of the gas burner assembly of the exemplary cooktop appliance of  FIG. 1 . 
           [0017]      FIG. 7  provides an exploded, bottom perspective view of the gas burner assembly of the exemplary cooktop appliance of  FIG. 1 . 
           [0018]      FIG. 8A  provides a top view of a base of the gas burner assembly of the exemplary cooktop appliance of  FIG. 1 . 
           [0019]      FIG. 8B  provides a perspective view of the base of the gas burner assembly of the exemplary cooktop appliance of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    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. 
         [0021]      FIG. 1  illustrates an exemplary embodiment of a cooktop appliance  100  as may be employed with the present subject matter. Cooktop appliance  100  includes a panel  102 , e.g., a top panel. By way of example, panel  102  may be constructed of enameled steel, stainless steel, glass, ceramics, and combinations thereof. 
         [0022]    For cooktop appliance  100 , a utensil holding food and/or cooking liquids (e.g., oil, water, etc.) may be placed onto gas burner assemblies  200  at a location of any of gas burner assemblies  200 . Gas burner assemblies  200  can be configured in various sizes so as to provide e.g., for the receipt of cooking utensils (i.e., pots, pans, etc.) of various sizes and configurations and to provide different heat inputs for such cooking utensils. Gas burner assemblies  200  are supported on a top surface  104  of panel  102 , as discussed in greater detail below. Gas burner assemblies  200  provide thermal energy to cooking utensils above panel  102 . 
         [0023]    A user interface panel  110  is located within convenient reach of a user of the cooktop appliance  100 . For this exemplary embodiment, user interface panel  110  includes knobs  112  that are each associated with one of gas burner assemblies  200 . Knobs  112  allow the user to activate each burner assembly and determine the amount of heat input provided by each gas burner assemblies  200  to a cooking utensil located thereon. User interface panel  110  may also be provided with one or more graphical display devices that deliver certain information to the user such as e.g., whether a particular burner assembly is activated and/or the level at which the burner assembly is set. 
         [0024]    Although shown with knobs  112 , it should be understood that knobs  112  and the configuration of cooktop appliance  100  shown in  FIG. 1  is provided by way of example only. More specifically, user interface panel  110  may include various input components, such as one or more of a variety of touch-type controls, electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. User interface panel  110  may include other display components, such as a digital or analog display device designed to provide operational feedback to a user. 
         [0025]    Cooktop appliance  100  shown in  FIG. 1  illustrates an exemplary embodiment of the present subject matter. Thus, although described in the context of cooktop appliance  100 , the present subject matter may be used in cooktop appliances having other configurations, e.g., a cooktop appliance with one, two, or more additional burner assemblies. Similarly, the present subject matter may be used in cooktop appliances that include an oven, i.e., range appliances. 
         [0026]      FIG. 2  provides another top, perspective view of cooktop appliance  100  with a gas burner assembly  200  of cooktop appliance  100  shown removed from panel  102  of cooktop appliance  100 . As may be seen in  FIG. 2 , gas burner assembly  200  is removable from panel  102  of cooktop appliance  100 . In certain exemplary embodiments, no mechanical fastening connects gas burner assembly  200  to panel  102 . Thus, gas burner assembly  200  may not be fastened to panel  102 , and a user may simply lift gas burner assembly  200  upwardly to remove gas burner assembly  200  from panel  102 , as shown in  FIG. 2 . In such a manner, top surface  104  of panel  102  below gas burner assembly  200  may be easily accessible and cleanable. 
         [0027]      FIG. 3  provides a perspective, section view of cooktop appliance  100 . As shown in  FIG. 3 , cooktop appliance  100  includes control valves  120 , fuel lines  122  and fuel orifices  124 . Control valves  120  may be mounted to panel  102  at a bottom surface  106  of panel  102 . Fuel lines  122  and fuel orifices  124  may also be positioned below panel  120 , e.g., at or adjacent bottom surface  106  of panel  102 . 
         [0028]    Control valves  120  are each coupled to a respective one of knobs  112 . Thus, a user may adjust control valves  120  with knobs  112 . Control valves  120  are configured for regulating fuel flow to gas burner assemblies  200 . For example, control valves  120  block fuel flow to gas burner assemblies  200  when control valves  120  are closed. Conversely, control valves  120  permit fuel flow to gas burner assemblies  200  when control valves  120  are open. A user may selectively adjust control valves  120  between the open and closed configurations with knobs  112  in order to regulate fuel flow to gas burner assemblies  200 . 
         [0029]    Fuel lines  122  extend between control valves  120  and fuel orifices  124 . Thus, control valves  120  and fuel orifices  124  may be coupled to fuel lines  122 . When control valves  120  are open, fuel, such as propane or natural gas, may flow through fuel lines  122  to fuel orifices  124 . From fuel orifices  124 , the fuel may flow into gas burner assemblies  200  where the fuel may be combusted, as discussed in greater detail below. 
         [0030]    Between fuel orifices  124  and gas burner assemblies  200 , fuel from fuel orifices  124  may entrain and mix with air. Cooktop appliance  100  includes features for assisting mixing of air and fuel as the fuel enters gas burner assemblies  200 . In particular, cooktop appliance  100  includes mixing tubes  126  that receive the fuel and air and facilitate fluid mixing of the fuel and air. For example, mixing tubes  126  may be Venturi mixers that define tapered channels such that a pressure of the fuel and air decreases while a velocity of the fuel and air increases. Other suitable means for mixing fuel and air are also contemplated and within the scope of the present subject matter. Downstream of mixing tubes  126 , the pressure of the fuel and air may increase while the velocity of the fuel and air decreases to further assist fluid mixing between the fuel and air entering gas burner assemblies  200 . 
         [0031]      FIG. 4  provides a section view of gas burner assembly  200 .  FIG. 5  provides an exploded, perspective view of one of gas burner assemblies  200 .  FIG. 6  provides a bottom, perspective view of gas burner assembly  200 .  FIG. 7  provides an exploded, bottom view of gas burner assembly  200 .  FIGS. 8A and 8B  shown top and perspective views, respectively, of a base of gas burner assembly  200 . Various features of gas burner assembly  200  are discussed in greater detail below in the context of  FIGS. 4 through 8 . 
         [0032]    As may be seen in  FIGS. 4 through 8 , gas burner assembly  200  includes a grate  210  and a burner  240 . Grate  210  is configured for supporting a cooking utensil, such as a pot, pan, etc. For example, grate  210  includes a plurality of elongated members  212 , e.g., formed of cast metal, such as cast iron. The cooking utensil may be placed on the elongated members  212  of grate  210  such that the cooking utensil rests on an upper surface of elongated members  212 . Elongated members  212  of grate  210  may include an outer frame  214  that extends around or defines a perimeter of grate  210  and/or gas burner assembly  200 . Thus, outer frame  214  may be positioned at an outer portion  219  of grate  210 . Grate  210  may rest on panel  102  at outer frame  214  of grate  200 . Thus, a bottom surface of outer frame  214  may rest on top surface  104  of panel  102 . As shown in  FIG. 5 , outer frame  214  of grate  210  may be square or rectangular in certain exemplary embodiments. Within outer frame  214 , elongated members  212  may define an inner passage  216  that extends vertically through grate  210 . Thus, fluid, such as air, may flow through grate  210  via inner passage  216 . 
         [0033]    As may be seen in  FIG. 5 , burner  240  may be positioned at a central portion  218  of grate  210 . Thus, burner  240  may be positioned at or within inner passage  216  of grate  210 , e.g., such that air within inner passage  216  of grate  210  flows by, around or through burner  240 . Burner  240  may include a cap  242  and a base  244 . Cap  242  of burner  240  may be mounted to grate  210 . In particular, cap  242  may be integrally formed with grate  210 , e.g., such that grate  210  and cap  242  of burner  240  are formed of or with a common piece of material. For example, grate  210  and cap  242  of burner  240  may be cast as a single, continuous piece of metal, such as cast iron. 
         [0034]    Base  244  of burner  240  is mounted to cap  242  of burner  240 , e.g., with fasteners, such that base  244  and cap  242  of burner  240  form flame ports of burner  240 , as discussed in greater detail below. Thus, cap  242  of burner  240  and base  244  of burner  240  may be separate pieces of material, such as cast metal, that are mounted to each other to form burner  240 . However, according to alternative embodiments, burner  240  may be formed from a single piece of material or from more than two pieces of material. 
         [0035]    As shown in  FIGS. 3 and 4 , burner  240  includes a burner ring  250  positioned on grate  210 . Burner ring  250  has a fuel chamber  252  and a plurality of flame ports  254 . Cap  242  of burner  240  may define an inner air passage  246  that allows air to flow through burner  240  at burner ring  250 . Fuel chamber  252  of burner ring  250  may extend circumferentially around passage  246  within base  244 .  FIG. 8A  and  FIG. 8B  provide top and perspective views of base  244  of burner  240 , respectively. As shown, fuel chamber  252  of burner ring  250  may further define a circumferential wall  260  that is positioned radially between the air passage  246  and fuel chamber  252  within burner  240 . 
         [0036]    According to the illustrated exemplary embodiment, circumferential wall  260  extends vertically and defines the plurality of flame ports  254  extending from fuel chamber  252 . Flame ports  254  open into inner air passage  246 . More particularly, according to one exemplary embodiment, flame ports  254  may be defined at least in part by a plurality of channels  262  ( FIG. 8 ) that extend through circumferential wall  260 . As shown, flame ports  254  are notched into an upper surface of circumferential wall  260 . However, according to alternative exemplary embodiments, flame ports  254  may be formed in other suitable ways, such as, e.g., by drilling through circumferential wall  260 . 
         [0037]    As best shown in  FIGS. 8A and 8B , flame ports  254  extend through circumferential wall  260  at an angle relative to a radial direction R. More specifically, as shown in  FIG. 8A , each flame port  254  may define a longitudinal direction A that is oriented at an angle  264  relative to the radial direction R. According to some exemplary embodiments, angle  264  may be between 0 and 45 degrees, or any other suitable angle. According to the illustrated embodiment, angle  264  is approximately 15 degrees. In this regard, flame ports  254  create a flame pattern in the form of a swirl or vortex. Such a flame pattern may, for example, ensure that the fuel is more sufficiently aerated and may provide more uniform heating. 
         [0038]    Although the exemplary embodiment describes flame ports  254  as being oriented at an angle  264  relative to the radial direction R, one skilled in the art will appreciate that flame ports  254  may be configured and oriented in any other suitable manner to achieve desired fuel flow dynamics. For example, flame ports  254  could be curved or straight and may be angled up or down relative to a horizontal plane, or angled in any other suitable orientation. In addition, flame ports  254  may be rectangular, circular, oblong, or any other suitable shape and may vary in cross-section, e.g., flame ports  254  may narrow as they exit circumferential wall  260 . 
         [0039]    Although the illustrated embodiment shows burner  240  having a single burner ring  250 , one skilled in the art will appreciate that the present disclosure is not so limited. For example, according to an alternative exemplary embodiment, burner  240  may be a multi-ring burner. For example, such a multi-ring burner may have an inner burner ring and an outer burner ring concentrically positioned such that outer burner ring extends around inner burner ring. An inner fuel chamber may be separated from an outer fuel chamber by a wall within burner, and burner may be configured to supply fuel to a plurality of flame ports on the inner burner and outer burner, respectively. Other configurations are also possible and within the scope of the present subject matter. 
         [0040]    Referring back to  FIGS. 3 and 4 , grate  210  includes features for supplying fuel to burner  240 , e.g., to burner ring  250 . In particular, grate  210  defines a first internal fuel passage  220  and a second internal fuel passage  230 . First and second internal fuel passages  220 ,  230  are configured for directing fuel through grate  210  to burner  240 . According to the illustrated exemplary embodiment, first internal fuel passage  220  and second internal fuel passage  230  are contiguous with fuel chamber  252  of burner ring  250 . Thus, fuel from fuel passages  220 ,  230  may flow into fuel chamber  252  of burner ring  250  and exit fuel chamber  252  of burner ring  250  at flame ports  254  where such fuel may be combusted. Although two fuel passages  220 ,  230  are shown, one skilled in the art will appreciate that only a single fuel passage may be needed according to alternative embodiments. Alternatively, if a multi-ring burner is used, each passage  220 ,  230  may be configured to provide fuel to a single ring of the multi-ring burner. Other configurations are also possible. 
         [0041]    By mounting burner  240  to grate  210  and directing fuel through grate  210  to burner  240 , cleaning panel  102  below gas burner assembly  200  may be facilitated. For example, as shown in  FIG. 3 , burner  240  may be mounted to grate  210  such that burner  240  is suspended above or spaced apart from top surface  104  of panel  102 . With burner  240  separated from top surface  104  of panel  102 , heat transfer between burner  240  and panel  102  may be limited. Thus, panel  102  may be cooler during operation of gas burner assembly  200  relative to burners that contact panel  102 , and burning of spilled or overflowed food particles on top surface  104  of panel  102  may be reduced or limited. In addition, with burner  240  separated from top surface  104  of panel  102 , access to panel  102  below burner  240  may be easier than compared to burners that are positioned on and mounted to panel  102 , and a user may more easily reach below burner  240  to clean spills and overflows below burner  240 . Further, by supplying fuel through grate  210 , burner  240  need not receive fuel from directly below burner  240  through panel  102 . Thus, panel  102  may have no holes, less holes and/or smaller holes directly below burner  240  relative to burners that are positioned on and mounted to panel  102  and receive fuel from directly below the burners. As shown in  FIGS. 2 and 3 , an igniter  130  may be mounted to panel  102  below burner  240 , in certain exemplary embodiments. 
         [0042]    As may be seen in  FIGS. 3 and 4 , at least a portion of first and second internal fuel passages  220 ,  230  may be positioned above flame ports  254  of burner  240 . In particular, at least a portion of fuel passage  220 ,  230  may be positioned above flame ports  254  of burner ring  250 . In such a manner, a vertical space occupied by gas burner assembly  200  may be reduced, and gas burner assembly  200  may have a compact vertical profile. In particular, utilizing first and second internal fuel passages  220 ,  230  to supply fuel to burner  240  assists with reducing a vertical height of gas burner assembly  200  relative to burners that deliver fuel to burners from below the flame ports due to the required spacing between the burners and a cooking utensil needed for proper combustion of fuel. In such a manner, cooktop appliance  100  may have a sleek, low profile that is preferred by certain consumers by delivering fuel to burner  240  through grate  210 . As an example, a total vertical height of gas burner assembly  200  may be no greater than three inches in certain exemplary embodiments. According to the illustrated embodiment, grate  210  is configured such that a bottom of cap  242  is positioned below a counter surface when cooktop appliance  100  is installed on a counter. 
         [0043]    First internal fuel passage  220  extends between an inlet  222  and an outlet  224 . Inlet  222  of first internal fuel passage  220  is positioned at or adjacent outer portion  219  of grate  210 . Conversely, outlet  224  of first internal fuel passage  220  is positioned at or adjacent central portion  218  of grate  210 . Thus, first internal fuel passage  220  may extend between outer portion  219  and central portion  218  of grate  210  within one of the elongated members  212  of grate  210 . First mixing tube  226  is positioned at inlet  222  of first internal fuel passage  220 . First mixing tube  226  may also be positioned above one of fuel orifices  124 , as shown in  FIG. 3 . Thus, fuel from one of fuel orifices  124  may pass through first mixing tube  226  and enter first internal fuel passage  220  at inlet  222  of first internal fuel passage  220 . Outlet  224  of first internal fuel passage  220  is contiguous with fuel chamber  252  of burner ring  250 . Thus, fuel from first internal fuel passage  220  may flow into burner  240  via outlet  224  of first internal fuel passage  220 . 
         [0044]    Second internal fuel passage  230  also extends between an inlet  232  and an outlet  234 . Inlet  232  of second internal fuel passage  230  is positioned at or adjacent outer portion  219  of grate  210 . Conversely, outlet  234  of second internal fuel passage  230  is positioned at or adjacent central portion  218  of grate  210 . Thus, second internal fuel passage  230  may extend between outer portion  219  and central portion  218  of grate  210  within one of the elongated members  212  of grate  210 . Second mixing tube  236  is positioned at inlet  232  of second internal fuel passage  230 . Second mixing tube  236  may also be positioned above one of fuel orifices  124 , as shown in  FIG. 3 . Thus, fuel from one of fuel orifices  124  may pass through second mixing tube  236  and enter second internal fuel passage  230  at inlet  232  of second internal fuel passage  230 . Outlet  234  of second internal fuel passage  230  is contiguous with fuel chamber  252  of burner ring  250 . Thus, fuel from second internal fuel passage  230  may flow into burner  240  via outlet  234  of second internal fuel passage  230 . 
         [0045]    As shown in  FIGS. 3 and 4 , first and second mixing tubes  226 ,  236  may be positioned opposite each other on gas burner assembly  200 . In particular, burner  240  may be positioned between first and second mixing tubes  226 ,  236 . Thus, first and second internal fuel passages  220 ,  230  may also be positioned opposite each other on gas burner assembly  200 , and burner  240  may be positioned between first and second internal fuel passages  220 ,  230 . In particular, outlet  224  of first internal fuel passage  220  may be positioned opposite outlet  234  of second internal fuel passage  230  on burner  240 . 
         [0046]    Grate  210  may be constructed of or with any suitable material. For example, grate  210  may be constructed of or with a single piece of cast metal. In particular, grate  210  may be formed of cast iron with first and second internal fuel passages  220 ,  230  formed within grate  210  using disposable cores during the casting process. First and second mixing tubes  226 ,  236  may also be integrally formed with grate  210  or may be separate components mounted, e.g., fastened, to grate  210 . 
         [0047]    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.