Abstract:
A refrigerator includes a cabinet having a frontal opening. A door assembly is pivotally mounted across the frontal opening of the cabinet to provide access to food items stored therein. The door assembly includes a door pan having a front face portion, as well as a top panel portion, a bottom panel portion and opposing side panel portions that establish a plurality of corners. A bracket is affixed each of the plurality of corners to provide support for the door pan, with each bracket being clinched at a plurality of locations to secure the bracket in place. By affixing the bracket through clinching, the need for a subsequent finishing step is eliminated.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention pertains to the art of refrigerators and, more particularly, to a refrigerator door assembly provided with reinforcing corner brackets that are secured to a door pan portion of the refrigerator door assembly through a clinching process. 
         [0003]    2. Discussion of the Prior Art 
         [0004]    In constructing a refrigerator, it is highly desirable to minimize the weight of a cabinet shell portion to reduce manufacturing, transportation and additional associated costs, yet it is imperative that the cabinet be structurally sound in order to counteract loads exerted thereon without deforming. Mainly due to cost efficiencies and flexibility in workmanship, it has been commonplace to utilize sheet metal in the forming of most refrigerator cabinets on the market today. Since sheet metal is thin and rather high loads tend to be concentrated on the shell, particularly by the opening and closing of a weighted down refrigerator door, a fair amount of effort has been applied in this art to provide reinforcement for such a refrigerator cabinet shell. Of course, an additional important concern is the ease of assembly, as well as the overall aesthetics, of the cabinet as a whole. 
         [0005]    With this in mind, it has been proposed to form the side and top walls of a refrigerator cabinet shell out of a single piece of bent sheet metal and then to attach thereto rear and bottom walls. That is, the side walls and top wall are integrally formed by bending a single piece of sheet metal forming a plurality of corner regions. The cabinet is fitted with a liner and then foam insulation is added which, once cured, provides both structural support and thermal retention. Equally important as the fabrication of the cabinet is the fabrication of a door assembly for the refrigerator. Without proper support, stresses created by food and other items supported on door shelves will cause the door to bend, warp or sag. This is particularly true with side-by-side refrigerators which provide an abundance of shelf space on the doors. 
         [0006]    Refrigerator doors are constructed in a manner similar to that describe above for refrigerator cabinets. In general, a door pan is formed by bending a sheet of metal to form a front face portion and top, bottom and opposing side panel portions that define at least four corner regions. In order to provide strength, particularly on a hinged side of the door, portions of the opposing side panel portions are folded over onto respective ones of the top and bottom panel portions forming an overlap. The overlap occurs at each of the four corner portions and is further reinforced by welding. However, as the size and weight of items supported on refrigerator doors have increased, the door and, in particular, the hinge side of the door required additional reinforcement. Thus, manufacturers have proposed adding hinge-side corner brackets to the door pan. Unfortunately, the presence of the overlap prevents the corner bracket from properly nesting in the corner. Therefore, in order to accommodate the bracket, the overlap is cut out and removed from the hinge side of the door. Once removed, the corner bracket is positioned and welded to the door pan. 
         [0007]    Unfortunately, removing the overlap exposes metal surfaces of the door pan. As exposed metal surfaces will, over time, rust, removing the overlap eliminates any possibility of using pre-painted or pre-finished material other than stainless steel. Likewise, welding the corner brackets to the door pan in combination with pre-painted material is undesirable. In particular, the heat generated during the welding process will damage the finish applied to the door pan. Therefore, when brackets are attached to the door pan, an additional manufacturing step is required. More specifically, once the brackets are affixed to the door pan, a subsequent painting or finishing process is needed to complete the door. While other methods of joining, such as rivets, screws and the like, do not require heat, they remain noticeable and thus require a cosmetic cover to ensure a seamless, finished appearance. 
         [0008]    In the art, corner brackets have only been employed on the hinge side of the door. While this process certainly reduces the number of component and steps required to fabricate a door, assembly lines required constant modification in order to make right hand and left hand doors. That is, first the assembly line is configured for a run of, for example, right hand doors. Once a series of right hand doors are complete, the line is reconfigured to run left hand doors. With this configuration, the remainder of the assembly process is put on hold until enough right and left hand doors are stockpiled. Obviously, this process adds to overall assembly time. In the highly competitive field of home appliances, eliminating manufacturing steps and reducing assembly time is very desirable. 
         [0009]    Based on the above, there exists a need in the art for a refrigerator door assembly that can be manufactured using a minimal number of processing steps. More specifically, there exists a need for a door assembly that can be reinforced without using a process that would damage a pre-existing exterior finish or require cosmetic covers to conceal unfinished portions of a door pan. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention is directed to a refrigerator including a cabinet having first and second laterally spaced upstanding side walls that are interconnected by a top wall to form a frontal opening. In addition, the refrigerator includes a door assembly pivotally mounted relative to the cabinet for closing the frontal opening. The door assembly includes a door pan having a front face portion, as well as a top panel portion, a bottom panel portion and opposing side panel portions that collectively establish a plurality of corners. An end section of at least one of the opposing side panel portions is provided with an upper, in-turned flange that is substantially co-planar with the top panel portion. The upper, in-turned flange and the top panel portion are formed so as to collectively define a hinge opening that establishes a hinge corner. In order to provide structural support for the door assembly, a corner bracket is affixed to the door pan at the hinge corner. In accordance with a preferred form of the invention, the corner bracket includes a first leg portion that extends to a second, substantially perpendicular, leg portion. When installed on the door pan, the first leg portion extends along the top panel portion and the second leg portion extends along one of the side panel portions. In order to provide a receiving point for a hinge, the first leg portion of the corner bracket is provided with an opening that aligns with the hinge opening. In this manner, a hinge can be positioned at the hinge corner to define a pivot axis for the door. 
         [0011]    In accordance with the invention, the corner bracket is fixedly secured at the hinge corner using a mechanical clinching process. More specifically, a series of mechanical clinches are used to join the corner bracket to each of the top panel portion and the side panel portion of the door pan. As clinching is a process of forming a mechanical bond between at least two materials without the use of heat, the absence of heat advantageously enables the use of a pre-painted or pre-finished material in the construction of the door pan. In this manner, additional painting or finishing process is eliminated from the production line. Moreover, both pre-painted and stainless steel doors can be manufactured on the same assembly line. In further accordance with the most preferred form of the invention, a corner bracket is secured to each of the plurality of corners of the door pan. In this manner, not only is the door pan further strengthened, but right and left hand doors can be run on the same assembly line at the same time thereby making refrigerator fabrication a more seamless and efficient process. 
         [0012]    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 
         [0013]      FIG. 1  is a partial left perspective view if a side-by-side refrigerator incorporating a door assembly constructed in accordance with the present invention; 
           [0014]      FIG. 2  is a perspective view of a door pan portion of the door assembly constructed in accordance with the present invention; 
           [0015]      FIG. 3  is an enlarged detailed view of a corner portion of the door pan of  FIG. 2 , illustrating a corner bracket secured to the door pan n accordance with the present invention; 
           [0016]      FIG. 4  is an exploded detailed view of the corner portion of  FIG. 3 , with the corner bracket removed from the door pan; and 
           [0017]      FIG. 5  is an enlarged cross-sectional view of a section of the corner portion of  FIG. 3 , illustrating a clinch joint employed to secure the corner bracket to the door pan. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]    With initial reference to  FIG. 1 , a side-by-side refrigerator is generally indicated at  2 . Refrigerator  2  includes a cabinet shell  4  including a pair of laterally spaced side walls  6  and  7  interconnected by a top wall  8 . Cabinet  4  defines a freezer compartment  10  and a fresh food compartment  12  that are separated by an intermediate wall or mullion  14 . In a manner known in the art, refrigerator  2  includes a freezer door assembly  18  that selectively provides access to freezer compartment  10  and a fresh food door assembly  20  that provides access to fresh food compartment  12 . Towards that end, each door assembly  18  and  20  is provided with a corresponding handle  23  and  24 . In a manner also known in the art, freezer door assembly  18  is provided with an ice/water dispensing assembly  28  that enables a consumer to retrieve ice and/or water from the front of refrigerator  2 . Both freezer door assembly  18  and fresh food door assembly  20  are pivotal about respective vertical axes defined by upper hinges  31  and  32  and lower hinges (not shown). 
         [0019]    In general, the structure described above is known in the art and has been provided for a more complete understanding of the figures. The present invention is particularly directed to the construction of freezer door assembly  18  and/or fresh food door assembly  20 . However, as each door assembly  18 ,  20  is preferably, similarly formed, a detailed description will be made with respect to freezer door assembly  18  with an understanding that fresh food door assembly  20  can include corresponding structure, although without structure associated with dispensing assembly  28 . 
         [0020]    As best shown in  FIG. 2 , freezer door assembly  18  includes a door pan  43  having a front face portion  45 , as well as a top panel portion  48 , a bottom panel portion  49  and opposing side panel portions  50  and  51  that collectively define a plurality of corners  54 - 57 . In addition, in order to accommodate ice/water dispensing assembly  28 , door pan  43  is provided with an opening  60 . In the embodiment shown, each panel portion  48 - 51  includes a corresponding in-turned flange that establishes an upper, rear face portion  68  (also see  FIG. 3 ), a lower, rear face portion  69  and side, rear face portions  70  and  71  respectively. Face portions  68 - 71  provide structure for mounting an inner door liner (not shown) to door pan  43 . 
         [0021]    In accordance with a preferred embodiment of the present invention as illustrated in  FIG. 3 , side panel portion  50  includes a tab that defines a tab member  74  which is folded so as to be substantially coplanar with top panel portion  48 . Likewise, rear face portion  70  is provided with a tab defining a tab element  75  that is also folded so as to be substantially coplanar with top panel portion  48 . Tab member  74  and tab element  75 , in combination with top panel portion  48 , define an aperture or hinge opening  77  at corner  54 . In addition to forming hinge opening  77 , tab member  74 , tab element  75  and top panel portion  48  define a slot  80 . As shown, slot  80  extends fore-to-aft across top panel portion  48 , spaces top panel portion  48  from both tab member  74  and tab element  75 , and leads into hinge opening  77 . In accordance with the invention, hinge opening  77  actually defines a hinge corner for door pan  43 . Of course, it should be understood that corner  55  would include similar structure so as to also define a longitudinally opposed hinge corner. Hinge  31  is provided with a post or spindle (not shown) that extends into opening  77  to define the axis of rotation for door  18  as discussed further below. In order to provide sufficient structural support to enable door  18  to withstand the rigors of repeated opening and closing, as well as for supporting food items, a corner bracket  90  is affixed at each of corners  54  and  55 . Most preferably, a corner bracket  90  is affixed at each corner  54 - 57  to provide both support and facilitate efficiency in manufacturing. By providing a bracket  90  on each corner  54 - 57 , both right and left hand doors can be advantageously manufactured at the same time so as to more efficiently utilize production resources. 
         [0022]    As best shown in  FIGS. 3 and 4 , corner bracket  90  is provided with a first leg portion  93  and a second leg portion  94  that projects substantially perpendicularly from first leg portion  93 . As shown, first leg portion  93  includes an opening  96  that aligns with hinge opening  77 . In accordance with one aspect of the invention, when employed in a lower corner position, first leg portion  93  is provided with additional openings  97 - 99  which register with corresponding openings  100 - 102  respectively and which are employed for attaching a door closure cam (opening  100 ) and/or for mounting a lower door stop (openings  101  and  102 ). Conversely, when employed in an upper corner position, first leg portion  93  may only include a single opening (not shown) for attaching a trim piece. In any event, first leg portion  93  includes a first in-turned flange section  103  and a second in-turned flange section  104 . When corner bracket  90  is affixed to, for example corner  54 , first, in-turned flange  103  abuts front face portion  45  while second, in-turned flange section  104  abuts or nests against upper, rear face portion  68  to properly locate corner bracket  90  in corner  54 . In the preferred embodiment, second leg portion  94  includes a terminal segment  107  that leads to an angled segment  108 . Angled segment  108  extends to a third segment  109  that is also substantially parallel to first leg portion  93 . Actually, third segment  109  extends towards and interconnects with first in-turned flange  103 . In addition, second leg portion  94  is provided with an in-turned flange  112  that is adapted to nest against side, rear face portion  70  when corner bracket  90  is affixed at corner  54 . 
         [0023]    Reference will now be made to  FIGS. 3 and 5  in describing a preferred method of attaching corner bracket  90  to door pan  43 . In order to allow the use of pre-painted materials in the construction of door pan  43 , corner bracket  90  is joined to door pan  43  without exposing any metal surfaces and using a non-heat generating, non-destructive process. In the most preferred form of the present invention, corner bracket  90  is affixed at corner  54  through a mechanical clinching process. With this technique, a joint is formed having an overlap portion. The joint is actually constituted by the material to be joined. A distinct advantage of this particular process is that the metal is not sheared after pre-finishing as when employing a toggle lock joint, nor is there any significant heat generation such as associated with welding, spot welding and the like. 
         [0024]    In accordance with the invention, corner bracket  90  can be affixed at corner  54  using either a standard clinching or a spot clinching process. In order to provide a robust attachment to corner  54 , corner bracket  90  is clinched in a plurality of locations spaced about first leg portion  93 , as represented at  117  in  FIG. 3 , as well as along in-turned flange  103  of second leg portion  94  as represented at  118 . As best shown in  FIG. 5 , each clinch  117  is accomplished by pressing a section of rear face portion  68  through in-turned flange  104  of corner bracket  90  to form an overlap section  120 . Overlap  120  mechanically joins bracket  90  with door pan  43 . A corresponding interconnection occurs for each clinch  118 . Due to the absence of shearing forces and heat when forming each clinched joint, a pre-painted material can be used in the production of door pan  43 . In this manner, additional production or finishing steps can be eliminated from an overall production process to increase production efficiency without sacrificing quality of the finished product. Moreover, the present invention enables both pre-painted and stainless steel doors to be manufactured on the same assembly line. 
         [0025]    Although described with reference to a preferred embodiment of the present invention, it should be readily apparent to one of ordinary skill in the art that various changes and/or modifications can be made to the invention without departing from the spirit thereof. In general, the invention is only intended to be limited to the scope of the following claims.