Patent Application
20060028105
Refrigeration appliances, such as refrigerators and freezers typically have doors which can be opened to allow a user to access a refrigerated compartment in the interior of the appliance. In order to assist in maintaining the compartment in a refrigerated state, the doors are usually insulated. In many instances refrigeration appliance doors are formed of a sheet metal material that is bent or drawn into a shape in which the door is provided with a thickness to accommodate the insulation material, among other things. As such, the door has a front surface area, and top, left, right and bottom side surface areas formed from sheet metal material.
In order to form the top, bottom, right and left side surface areas in metal sheets, it has been required that a seam or discontinuity must be provided between at least some of the adjacent side surface areas. Such a seam or discontinuity visually detracts from the appearance of the appliance. While plastic appliance door constructions have been able, through melting and molding operations not available when working with metal, for example see U.S. Pat. No. 6,630,097, to form seamless corners, until now, metal door constructions have required seams or other discontinuities at the corners.
In some cases, the seam or discontinuity is caused by having terminal edges of the surface areas abut one another after being bent into shape, as shown in U.S. Pat. No. 4,484,703, which require the extra step of welding (
It would be an improvement in the art if an arrangement were provided for forming corners for a metal door for a refrigeration appliance in which the side surface areas were joined together without a seam or discontinuity in order to avoid the drawbacks mentioned above.
The present invention overcomes the drawbacks of the prior art in that a refrigerated appliance is provided with a door which comprises an outer metal panel having a generally rectangular front surface area lying generally in a first plane, top, left, right and bottom side surface areas formed as extensions from the front surface area, and connected thereto via radiused bends to orient the side surface areas in planes approximately 90 degrees from the plane of the front surface area, without seams or other discontinuities between any of the front or side surface areas.
In an embodiment, flanges extend from each of the top, left, right and bottom sides, the flanges being oriented generally in a plane approximately parallel to the plane of the front surface area, adjacent flanges having overlapping areas which are secured together with fastening elements.
In an embodiment, adjacent ones of each of the side surface areas are joined at bends having radii in the range of 6-20 mm.
In an embodiment, including flanges extending from said side surface areas approximately parallel to the first plane, a plastic door liner is engaged with the flanges, and a foamed-in-place insulation material is adhered between the liner and an inner surface of the outer metal panel.
In an embodiment, the front surface has an outwardly convex shape, and in other embodiments, the front surface has a planar shape.
In an embodiment, the side surface areas are joined to the front surface area at bends having a radius in the range of 6-20 mm.
The present invention is directed to a door for a refrigeration appliance, such as a refrigerator, freezer, ice maker, or a combination appliance having both a refrigerated (fresh food) compartment and a freezer (frozen food) compartment. Throughout this specification, the terms refrigerator or refrigeration appliance will be used to encompass all such devices.
A refrigerator is shown generally at 20 in
As seen in
The front surface area 28 of the door 20 may be generally planar in shape, or may have a generally outwardly convex shape, as shown in
The front surface area 28 of the door 20 is formed from the sheet metal panel 29, typically a form of steel such as carbon steel or stainless steel. The surface of the sheet metal panel 29 may be smooth or may have a texture applied to it. It may be brushed or painted, or have some other appearance enhancing treatment applied to it. In a preferred embodiment, the thickness of the sheet metal panel 29 is less than 0.040 inches (0.1 mm) and most preferred, is less than 0.030 inches (0.076 mm) in order to reduce weight and cost. Sufficient strength is provided to the door as described below.
The sheet metal material 29 is preferably acted upon by a drawing die to form a top 32, right 34, left 36 and bottom 38 side surface area of the door 20 as shown in a rear inside view of the door panel in
In the forming process, the top 32, right 34, left 36 and bottom 38 side surface areas of the door 20 are formed without any seams or discontinuities between each other. The adjacent sides are joined to each other at a radius area 40 (
As illustrated in
The flanges 42-48 each have a length such that as they are folded over, end portions 50, 52 of adjacent flanges overlie each other, and fill the corner areas to the greatest extent possible in order to prevent leakage of liquid foam insulation used during manufacture of the door, as described below, or to avoid or reduce the need for blocking material for the foam. This overlap 50, 52 of the flanges 42-48 permits the use of a fastening element 54 to secure the adjacent metal flanges together to assist in strengthening the door 20. The fastening elements 54 may be interlocking stamped configurations, such as toggle locks, which do not require the use of additional fasteners. The fastening elements 54 may also comprise a welding or soldering attachment of the two flange end portions 50, 52. Further, the fastening elements 54 may comprise separate mechanical fasteners, including rivets or threaded fasteners.
As best shown in
A foamed-in-place insulation material 58 is injected into the space between the metal panel 29 and the door liner 56 which expands to fill the space and adheres to the liner 56 and the inner surface 51 of the outer metal panel before it hardens, such as disclosed in U.S. Pat. No. 5,704,107, incorporated herein by reference. The combination of the relatively tight radiused corners of the door panel 29, the flanges 42-48 which are secured to one another, the door liner 56 and the foamed-in-place insulation material 58 work together to provide sufficient structural strength and rigidity to the completed door such that no additional lateral or vertical support members are required to prevent the door from sagging, racking or flexing beyond acceptable limits in a normal sized domestic refrigeration appliance, despite the relatively thin material used for the outer metal panel 29.
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.
