Patent Publication Number: US-9903596-B2

Title: Broiler shield for a residential oven and residential oven incorporating same

Description:
BACKGROUND OF THE INVENTION 
     Many residential ovens which include electric heating elements include a broiler heating element mounted in an upper portion of a cooking cavity of the oven. The broiler heating element is activated to broil food items which are placed on an oven rack located directly underneath the broiler heating element. 
     A side view of the interior of such a residential oven is illustrated in  FIG. 1 . As shown therein, the residential oven  100  includes a rear wall  102 , a lower wall  104  and an upper wall  106 . A door  105  is attached to the front of the oven and the door  105  can be opened and shut using a handle  107 . 
     The plurality of rack mounts  103  are provided on opposite sidewalls of the oven. This allows one or more racks  109  to be mounted in the interior of the oven  100  at different heights. 
     A lower heating element  111  is provided in a lower portion of the cooking cavity of the oven  100 . In addition, a broiler heating element  110  is located in an upper portion of the cooking cavity. The broiler heating element  110  can be used in conjunction with the lower heating element  111  during a normal baking operation. Alternatively, the lower heating element  111  alone might be used during a baking operation. 
     During a broiling operation, the lower heating element  111  is typically turned off, and the broiler heating element  110  alone is activated. The broiler heating element  110  emits heat and radiant energy which is projected downward onto the food items located on the rack  109  located directly underneath the broiler heating element  110 . 
     A broiler heating element  110  is typically constructed of a relatively thick resistive wire which has a circular cross sectional shape. When electricity passes through the broiler heating element  110 , the electricity causes the wire to emit heat and radiant energy. The radiant energy is emitted in all directions around the circular circumference of the wire. When a broiling operation is being conducted, the radiant energy emitted from the broiler heating element browns food items on an underlying rack. 
     While the radiant heat which is emitted downward from the broiler heating element impinges directly on food elements located beneath the broiler heating element, radiant heat which is emitted sideways or upward does not tend to reach the food items located underneath the broiler heating element. 
     In addition, because of the way broiler heating elements are shaped, more heat and radiant energy tends to impinge upon the center portions of an underlying rack than the front and rear portions of the underlying rack. This can result in uneven cooking and uneven browning of food items located on an underlying rack. 
     BRIEF SUMMARY OF THE INVENTION 
     One aspect of the invention is embodied in a broiler shield which is mounted above a broiler heating element of a residential oven, and which helps to reflect radiant energy emitted upward from the broiler heating element downward towards food items placed on an underlying rack. 
     Some embodiments of the broiler shield have angled reflectors that are positioned relative to front and rear portions of the broiler heating element so that radiant energy is effectively distributed to the front and rear portions of an underlying rack to promote more even cooking and browning of food items on the underlying rack. 
     Some embodiments of the broiler shield include a front extension that extends forward and downward from a front edge of the broiler shield, the front extension reflecting radiant energy emitted sideways from the front of a broiler heating element downwards toward the front portion of an underlying rack. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of the interior of a residential oven; 
         FIGS. 2A and 2B  are perspective views of broiler heating elements; 
         FIG. 3  is a cross-sectional view of the interior of a residential oven which includes a broiler shield; 
         FIGS. 4A and 4B  are plan and side views of a broiler shield; 
         FIGS. 5A and 5B  are plan and side views of another embodiment of a broiler shield; 
         FIG. 6  is a partial cross-sectional view of the interior of a residential oven which includes a broiler shield; and 
         FIGS. 7A and 7B  are plan and side views of another embodiment of a broiler shield. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 2A  illustrates a first embodiment of a broiler heating element  110  which can be used in a residential oven. As shown in  FIG. 2A , the broiler heating element  110  includes a connecting portion  118  which is used to couple the broiler heating element to a power supply. The broiler heating element  110  also includes front portions  114 ,  112  and rear portions  116  which join straight portions  113 . The continuous broiler heating element traces out a repeating S-shaped pattern. In addition, mounting elements  117  can be used to attach the broiler heating element  110  to the upper wall of a cooking cavity of a residential oven. In the embodiment illustrated in  FIG. 2A , the central front portions  114  do not project as far to the front of the oven as the outermost front portions  112 . 
       FIG. 2B  illustrates another embodiment of a broiler heating element  120 . In this embodiment, two separate heating elements are provided. An interior heating element  123  is located inside an exterior heating element  122 . The interior heating element  123  still includes front portions  124  and rear portions  126  which join a plurality of straight portions  123 . When this type of a broiler heating element is installed in an oven, the two heating elements  122 ,  123  can used together, or separately. 
       FIG. 3  illustrates a residential oven  100  which includes a broiler heating element  110  as illustrated in  FIG. 2A or 2B . A broiler shield  200  is mounted between the broiler heating element  110  and the upper wall  106  of the cooking cavity of the oven. As will be explained in greater detail below, the broiler shield  200  acts to reflect radiant energy emitted upwards and sideways by the broiler heating element back down onto food items located on an underlying rack. The shape of the broiler shield is designed to reflect the radiant energy emitted by the broiler heating element  110  so as to promote more even heating and browning of the underlying food items. 
       FIGS. 4A and 4B  illustrate a first embodiment of a broiler shield  200  which can be used in a residential oven. As shown in  FIGS. 4A and 4B , the broiler shield  200  includes a large planar central portion  202 . A front reflecting portion  210  extends forward from a forward edge  203  of the central portion  202 . A rear reflecting portion  220  extends rearward from a rearward edge  205  of the central portion  202 . As best illustrated in  FIG. 4B , the front reflecting portion  210  includes a first reflector  212  which extends forward and downward from a front edge of the central portion  202 . The front reflecting portion  210  also includes a second reflector  214  which extends upward and forward from a front edge of the first reflector  212 . 
     As also illustrated in  FIG. 4B , the rear reflecting portion  220  includes a first reflector  222  which extends downward and rearward from a rear edge of the central portion  202 . In addition, the rear reflecting portion  220  also includes a second reflector  224  which extends upward and rearward on the rear edge of the first reflector  222 . 
     As also illustrated in  FIG. 4B , a first acute angle A is formed between a plane of the central portion  202  and a plane of the second reflector  224 . Further, an acute angle B is formed between the plane of the central portion  202  and the plane of the first reflector  222  of the rear reflecting portion. Acute angles are also formed between the plane of the central portion  202  and the plane of the first reflector  212  and second reflector  214  of the front reflecting portion  210 . In some embodiments, the same acute angle A is formed between the plane of the central portion  202  and the plane of the second reflecting portion  214  of the front reflecting portion  210 . Likewise, the same acute angle B is formed between the plane of the central portion  202  and the plane of the first reflector  212  of the front reflecting portion  210 . 
     In some embodiments, the acute angle A is approximately 15°, and the acute angle B is approximately 30°. 
     The broiler shield also includes a front extension which extends forward from a front edge of the second reflector  214  of the front reflecting portion  210 . The front extension includes a planar portion  230  and a front reflector  232 . The plane of the planar portion  230  is approximately parallel to a plane of the central portion  202 . 
     An acute angle C is formed between the plane of the planar portion  230  and a plane of the front reflector  232 . In some embodiments, the acute angle C is approximately 60°. 
     The broiler shield further includes a rear extension  240  which extends rearward from the second reflector  224  of the rear reflecting portion  220 . The plane of the rear extension  240  is approximately parallel to the plane of the central portion  202 . 
       FIGS. 5A and 5B  illustrate an alternate embodiment of a broiler shield. This embodiment is similar to the embodiment illustrated in  FIGS. 4A and 4B , but includes additional features. Specifically, the embodiment illustrated in  FIGS. 5A and 5B  includes apertures  260  which are used to help mount a broiler heating element to the interior of a residential oven. This is explained in greater detail below. 
     In addition, mounting elements  250  are provided towards the rear of the broiler reflector. The mounting elements  250  comprise portions of the plate of material forming the broiler reflector which have been cut and bent upward. As illustrated in  FIG. 5B  the mounting elements  250  end up having an L-shape. As will be explained in further detail below, the mounting elements  250  are used to help mount the broiler reflector  200  to the upper wall of an oven. 
     The embodiment illustrated in  FIGS. 5A and 5B  also includes two beveled portions  242  on the side edges of the rear extension  240 . The beveled portions  242  can help to conform the broiler reflector to the shape of the interior of an oven cavity. 
     The embodiment illustrated in  FIGS. 5A and 5B  further includes a mounting hole  270  formed in the planar portion  240  of the front extension. The mounting hole  270  is also used to facilitate mounting of the broiler reflector to the upper wall of an oven cavity. 
       FIG. 6  shows a broiler reflector  200  mounted to the upper wall  106  of a residential oven  100 . The broiler reflector  200  is located between the upper wall  106  and a broiler heating element  110 . The broiler reflector is similar to the embodiment illustrated in  FIGS. 5A and 5B . 
     As illustrated in  FIG. 6 , mounting elements  117  project upward from the broiler heating element  110 , they pass through the apertures  260  in the broiler reflector, and they are attached to the upper wall  106  of the oven  100  by fasteners  270 . The mounting elements  250  on the broiler reflector project upward from the broiler reflector  200  and they are attached to the upper wall  106  of the oven  100  by fasteners  270 . 
     As explained with reference to  FIG. 2A , the broiler heating element  110  includes straight portions  113  which extend between front portions  112 ,  114  and rear portions  116 . A connecting portion  118  extends rearward to attach the broiler heating element  100  to a power supply. The connecting portion also serves to mount the rear portion of the broiler heating element  110  to the rear wall of the oven. 
     The rear portions  116  which connect straight portions  113  of the broiler heating element  110  emit radiant energy. Likewise, the front portions  112  and  114  which also connect the straight portions  113  of the broiler heating element  110  also emit radiant heat energy. The dashed lines in  FIG. 6  show the travel path of some of the radiant heat energy emitted by the front portions  112 ,  114  and rear portions  116 . The dashed lines also illustrate how the radiant energy is reflected by various portions of the broiler shield  200 . 
     Applicants believe that the radiant heat energy emitted upward and forward from the front portions  112 ,  114  of the broiler heating element are reflected downward and rearward by front reflector  232  of the broiler shield  200 . This radiant energy, which would otherwise not reach the underlying rack  109 , is instead directed down onto the front portions of the underlying rack  109 . 
     Likewise, radiant heat energy emitted upward and rearward from the front portions  112 ,  114  of the broiler heating element are reflected downward and rearward by the second reflector  214  of the front reflecting portion of the broiler shield  200 . Because the second reflector  214  is angled relative to the plane of the central portion  202  of the broiler shield, radiant energy reflected by the second reflector  214  is directed further toward the front of the underlying rack  109  than would be the case if the broiler shield were simply planar along its entire length. 
     Radiant energy emitted upward and forward by the rear portions  116  of the broiler heating element  110  is reflected downward by the second reflector  224  of the rear reflecting portion of the broiler shield. And because the second reflector  224  of the rear reflecting portion is also angled relative to the central portion  202  of the broiler shield, this radiant energy is reflected further toward the rear of the underlying rack than would be the case if the rear reflector  224  was not angled. 
     When no broiler shield is provided, or when a simple planer broiler shield is provided, more heat and radiant energy from the broiler heating element tends to reach the central portion of the underlying rack than the front and rear portions of the underlying rack. Thus leads to uneven cooking and browning of food items on the underlying rack. 
     However, when a broiler shield as illustrated in  FIGS. 4A, 4B, 5A and 5B  is mounted above a broiler heating element, portions of the radiant energy emitted by the broiler heating element that would otherwise be lost, or which would otherwise be reflected onto central portions of the underlying rack is instead redirected to the front and rear portions of the underlying rack. This leads to more even cooking and browning of food items on the underlying rack. 
     The relative positions of the front and rear reflecting portions could vary depending on the shape and configuration of the broiler heating elements. However, Applicants presently believe that it is most advantageous if the front reflecting portion and rear reflecting portions of the broiler shied are positioned more toward the center of the oven than the front and rear portions of the broiler heating elements which join the straight portions of the heating elements. 
       FIGS. 7A and 7B  illustrate yet another embodiment of a broiler shield. In this embodiment, the front reflecting portion  210  includes a first section  213  that extends downward from the front edge of the central portion  202  at approximately a 90° angle. A reflector  215  then extends forward and upward to the rear edge of the planar portion  230  of the front extension. Likewise, the rear reflecting portion  220  includes a first section  223  that extends away from the rear edge of the central portion  202  at approximately a 90° angle. A reflector  225  then extends rearward and upward to the front edge of the rear extension  240 . 
     In this embodiment, because the first sections  213 ,  223  extends away from the central portion  202  at a right angle, the reflectors  215 ,  225  have a greater surface area than the second reflectors  214 ,  224  in the embodiments in  FIGS. 4A, 4B, 5A and 5B . The larger surface area of the reflectors  215 ,  225  in the embodiment illustrated in  FIGS. 7A and 7B  cause a greater amount of the radiant energy emitted upward from the broiler heating element to be reflected back toward the front and rear portions of an underlying rack, as compared to the embodiments illustrated in  FIGS. 4A, 4B, 5A and 5B . 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.