Abstract:
A cooking appliance includes a gas burner module having a base structure upon which is secured at least a gas burner element and a gas orifice defining member in a predetermined alignment. The base structure is preferably formed from stamped steel. The burner module also preferably includes a gas igniter. The gas burner module is adapted to be mounted to heat an oven cavity of the cooking appliance. With this arrangement, tolerance build-up leading to misalignment between critical components is greatly reduced thereby improving manufacturing and combustion repeatability, as well as enhanced field replacement. In this manner, the cooking appliance will consistently operate within prescribed agency limitations.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to the art of cooking appliances and, more particularly, to a unitary gas burner module for use in a cooking appliance having a gas oven. 
     2. Discussion of the Prior Art 
     In general, cooking appliances utilizing gas burners to perform cooking operations are known in the art. Typically, such gas burners and other combustion components are positioned to radiate heat into an oven cavity within which is located a food item. That is, the gas burner could be positioned below an oven cavity panel or, alternatively, on an oven cavity surface. In either case, burning gas emitted from the gas burner element causes the temperature of the cavity to rise. In this manner, the food item undergoes a desired cooking operation. 
     In mounting a gas burner in an oven cavity, great concern must be taken in the alignment between the various combustion components, the most critical being the alignment between the gas burner element and a gas orifice. The gas orifice is provided to direct a gas flow having a distinct configuration into the burner element. Certainly, any changes in the configuration of the gas flow can result in improper or incomplete combustion. The configuration of the gas flow is most affected by misalignment of the orifice with respect to the gas burner. In any case, misalignment will cause improper combustion, resulting in greater emissions from the oven and a shortening of the life of the combustion components. 
     Characteristically, the gas burner and gas orifice are mounted to different structure within the cooking appliance. The mounting arrangement is generally necessitated by design and spatial constraints. Unfortunately, this typical mounting arrangement promulgates misalignment problems, whether in initial factory assembly or field replacement. As such, the efficiency of the oven is reduced and, by extension, so is the service life of the overall appliance. 
     Based on the above, there exists a need in the art for a cooking appliance employing a gas burner module. More specifically, there exists a need for a gas burner module formed as a single unit having arranged thereon at least the gas burner element and the gas orifice such as to minimize variability between units. In this manner, by-products of combustion exhausted from the cooking appliance will consistently fall within agency specifications. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to incorporating a gas burner module into a cooking appliance. That is, a cooking appliance including a cabinet and an oven cavity further includes a gas burner module positioned to radiate heat into the oven cavity. The gas burner module includes a base structure defined by a horizontal planar surface having arranged thereon at least a gas burner element and a gas orifice defining member which are maintained in a predetermined, fixed alignment. 
     In accordance with a preferred embodiment of the present invention, the base structure is formed from a stamped metal sheet adapted to be positioned inside the oven cavity. The metal sheet includes a plurality of mounting receptacles for securing the gas burner and gas orifice defining member to the base structure. More specifically, a pair of attachment brackets are employed to mount the gas burner element to the base structure, while a separate attachment bracket is utilized for further mounting the gas orifice defining member to the base structure. A gas igniter is secured at the gas burner element, at a position substantially spaced from the gas orifice defining member, to ignite gas flowing through the gas burner element. The module also includes a supply tube having an end fixed at the gas orifice defining member. With this overall arrangement, an integrated gas burner module is defined which can be mounted in a cooking appliance as a single unit, while assuring a desired alignment between the gas burner element and a gas orifice in order to eliminate assembly time variations and to assure efficient gas combustion with consistently low emissions. 
     Additional objects, features and advantages of the present 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 
     FIG. 1 is a perspective view of a cooking appliance incorporating a gas burner module constructed in accordance with the present invention; and 
     FIG. 2 is a perspective view depicting a top side of the gas burner module of the present invention removed from the cooking appliance of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With initial reference to FIG. 1, a cooking appliance incorporating the present invention is shown to take the form of a free-standing gas range unit. Range  2  includes a cabinet  4  having a front panel portion  5 , side panel portions  6 , bottom portion  7 , a range top  8  and main back panel  9 . In a manner known in the art, range top  8  can take on various forms. 
     Specifically, in the embodiment shown, range top  8  is shown as a gas cooktop incorporating various gas burner elements  11 - 14  and associated burner grates  15 - 18 . As shown, cabinet  4  further includes a front control surface  20 . Preferably, control surface  20  supports a plurality of control knobs  21 - 24  for controlling the activation/deactivation of gas burner elements  11 - 14  respectively. Furthermore, cabinet  4  includes a rear, upstanding control panel  30  arranged at an upper rear portion  31  of cabinet  4 . In the embodiment shown, control panel  30  includes a central control and display unit, generally indicated at  35 , for use in controlling first or upper oven  40  and second or lower oven  41 . 
     In a preferred embodiment, upper oven  40  includes a respective first or upper oven cavity  45  and, similarly, lower oven  41  includes a respective second or lower oven cavity  46  having a bottom portion  47 . In a manner known in the art, upper oven  40  has associated therewith a door  50  which can be pivoted by means of a handle  53 . Door  50  preferably includes a window  55  for viewing the contents of upper oven cavity  45 . In a similar manner, lower oven  41  has associated therewith a door  60  and a window  65 . 
     In a manner known in the art, range  2  is adapted to be mounted upon a supporting surface, such as a kitchen floor or the like. More specifically, a plurality of leg members, two of which are indicated in FIG. 1 at  79  and  80 , extend from bottom portion  7  at front and rear portions of cabinet  4 , along side panel  6 . Of course, corresponding leg members are also provided on the opposing side of range  2 . In any event, the various leg members  79  and  80  are preferably, vertically adjustable to also act as levelers for range  2 . Such type of leg leveler arrangements are widely known in the art of appliances, including ranges and refrigerators, such that the leveling function of leg members  79  and  80  does not form part of the present invention. 
     In general, the structure described above with respect to cooking appliance  2  is already known in the art and does not constitute part of the present invention. Therefore, this structure has only been described for the sake of completeness. Instead, the present invention is particularly directed to a gas burner module  100  positioned to radiate heat into respective oven cavities  45  and  46 . 
     Reference will now be made to FIG. 2 in describing the specific structure of burner module  100 . Since each oven cavity  45  and  46  includes an associated burner module, and the structure of each burner module is identical, a detailed description of burner module  100  as arranged within oven cavity  46  will be made and it is to be understood that a second burner module (not shown) having commensurate structure is preferably arranged in oven cavity  45 . 
     In accordance with a preferred form of the present invention, gas burner module  100  includes a unitary base member  105  having a central planar portion  108  including a peripheral rim  110  leading to a plurality of out-turned support flanges  111 - 115 . As will be discussed more fully below, positioned adjacent to support flanges  113  and  114  are flat mounting surfaces  116  and  117  respectively. Furthermore, extending about support flanges  111 - 115  are a plurality of openings, one of which is indicated at  118 , for mounting burner module  100  within cooking appliance  2 . As shown, central planar portion  108  includes an opening  120  extending longitudinally between support flange  111  and both support flanges  113  and  114 . In a preferred form of the invention, generally L-shaped downwardly displaced portions  123  and  124  extend along opposing sides of opening  120  toward rear flanges  113  and  114  respectively. Therefore, adjacent to rear flanges  113  and  114 , downwardly displaced portions  123  and  124  turn ninety-degrees and extend toward respective side flanges  112  and  115 . 
     Preferably, insulation package attachment points  130  and  131  are positioned at front corner portions of planar portion  108 . Each of attachment points  130  and  131  is preferably stamped into planar portion  108  and includes an associated central bore  133 ,  134  through which a mechanical fastener can extend to secure an insulation package (not shown). However, it should be understood that a variety of methods for establishing an attachment point could be used without departing from the scope of the present invention. 
     As will be detailed more fully below, gas burner module  100  is positioned in bottom portion  47  of oven cavity  46  (FIG.  1 ). Although not shown, a burner box can be arranged below bottom portion  47  for receiving module  100 . To secure module  100  in place within bottom portion  47 , the laterally outermost portions of flanges  112  and  115  are bent 90° allowing locating notches  140  and  141  to receive a respective oven bottom portion (not shown). On the other hand, tab elements  146  and  147 , that extend upwardly from opposing end portions of flange  111 , allow mounting of an exhaust flow directing false oven bottom (not shown). In order to facilitate installation and removal of module  100 , and enable gas orifice flow adjustments, a cut-out portion  153  is located between flanges  113  and  114 . Preferably, cut-out  153  is sized to enable access to a technician&#39;s hand, thereby enhancing the ability of the technician to adjust a gas metering orifice (not shown). 
     As best seen in FIG. 2, a gas burner assembly, generally indicated at  160 , is provided as part of gas burner module  100 . In accordance with one form of the invention, gas burner assembly  160  includes a gas burner  165 , depicted as a burner tube formed with a plurality of exit openings  166  arranged directly opposite opening  120 , having a first end  167  extending to an intermediate portion  168  and terminating in a second end  169 . More specifically, first end  167  of burner  165  is secured to flange  111  through a first attachment bracket  170  which preferably constitutes a crushed or flattened end portion of gas burner  165 , but which could constitute a separate element. Burner  165  is further secured to base member  105  through a second attachment bracket  173  which fastens intermediate portion  168  to mounting surface  117 . Preferably, burner  165  is fastened to bracket  173  using a spot weld process, while brackets  170  and  173  are screwed to flange  111  and mounting surface  117  respectively. However, while spot welding is the preferred method of fastening brackets  170  and  173  to burner  165 , other methods, including pierce riveting and the like, could be employed. 
     In accordance with the most preferred form of the present invention, a gas orifice defining member  180  is affixed to an orifice mounting or attachment bracket  181  which, in turn, is secured to an underside of mounting surface  116 . Leading to gas orifice member  180  is a gas supply line  190  which also forms part of module  100 . More specifically, gas supply line  190  has a first end  192  adjacent gas orifice member  180  and a second end  194  provided with a terminal connector  196  for attaching supply line  190  to a source of natural or propane gas (not shown). Gas burner assembly  160  further includes a gas igniter  200  for igniting a flow of gas emanating from exit openings  166  of burner  165 . More specifically, gas igniter  200  is operatively connected to control panel  30  through conductors  202  and  204 , such that activation of oven  41  operates igniter  200  to touch off the gas flow from burner  165 . In a preferred form, gas igniter  200  constitutes a hot element or glowbar-type igniter and includes a shield  206  which is fixed to burner  165  through bracket  173 , wherein shield  206  is adapted to protect igniter  200  from debris falling from oven cavity  46 . 
     With this overall construction, the gas orifice formed in gas orifice member  180  is maintained in a fixed alignment with burner  165 . In this manner, assembly line and tooling variability can be maintained at minimum levels. By lowering variability and reducing inconsistencies in the manufacturing process, the manufacturer is able to consistently produce appliances whose emission remain within agency specifications. In addition, ease of field replacement is enhanced. That is, in order to remove burner module  100  from range  2 , such as for replacement purposes, a technician simply disengages supply line  190  from a gas source at connector  196 , removes screws (not shown) from holes  118  in flanges  111 - 115 , and lifts burner module  100  out as a unit. Obviously, installation of a burner module  100  is performed in a corresponding manner. 
     Although described with reference to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, the need for a false bottom arranged over the gas module is not paramount. Further, the gas module of the present invention is configurable to be mounted in other gas oven arrangements such that the invention is not limited to dual oven gas ranges. In general, the invention is only intended to be limited by the scope of the following claims.