Patent Application
20080180011
1. Field of the Invention
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.
2. Discussion of the Prior Art
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.
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.
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.
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.
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.
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.
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.
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.
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.
With initial reference to
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.
As best shown in
In accordance with a preferred embodiment of the present invention as illustrated in
As best shown in
Reference will now be made to
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
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.
