Patent Publication Number: US-6209265-B1

Title: Refrigerator door corner construction

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a door for a refrigerator having load reinforced corners for reducing door loading stresses across the outer door skin. 
     BACKGROUND OF THE INVENTION 
     For several years the trend in domestic refrigerator cabinets has been to increase the size and in particular the width of the food compartments and doors in top or bottom mount refrigerators. 
     Typically, the refrigerator door is constructed from an outer door panel of sheet steel material having rearwardly extending side walls. The door has an inner liner wall of plastic material attached to the door panel. Foam insulation is injected in the space between the outer panel and the inner liner. The foam expands and cures to thermally insulate and rigidize the door. 
     In order to conserve costs, the amount of steel used in the manufacture of these doors is optimized. The practice is to use a relatively thin sheet of steel for the outer panel. Often this sheet is in the order of 0.017 inches thick. Consequently, in order for the refrigerator door to maintain it&#39;s integrity and support articles or items stored on door mounted shelves, one common approach is to reinforce the door with cross braces located within the space of the door between the inner liner and the outer door panel. The metal cross braces extend from the corners of the refrigerator outer panel in an X configuration to reinforce the refrigerator door. 
     Another known approach to rigidize the door is to use a sheet of paper, aluminum foil or cardboard embedded in the insulation injected into the door cavity. This paper sheet is sufficiently large to cover the inside of the door and is taped to the door to prevent shifting. The sheet improves the rigidity of the door without significantly adding to the weight or cost of the door. More recently, metal sheets have been substituted for paper to improve rigidity. However, the metal sheet adds more weight to the door. 
     While the above described approaches in refrigerator door construction improve the rigidity of the door, these solutions are more directed to reinforcing the door outer skin and inner liner. To further strengthen the door outer skin, the corners of the door, formed when the skin is rolled back onto itself to provide a supporting peripheral flange for the door liner have been welded to strengthen the corners. However, this results in the distribution of the corner hinge loading forces across the outer door skin which is the very problem for which the above methods of reinforcement are attempting to compensate. Clearly, there is a need for a refrigerator door corner construction that eliminates the problems associated with door corner loading, reinforces the door, and reduces load transfer from the corner through the door onto the relatively thin steel outer skin wall of the refrigerator door. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a refrigerator door construction having door corner brackets and linking strut supports that improve the rigidity of the door. 
     It is another object of the present invention to provide a refrigerator door construction having improved corner reinforcement adjacent the side walls of the refrigerator door to reduce the stresses loaded onto the outer skin of the door through the door corners. 
     The present invention relates to a refrigerator appliance and, in particular, a door for a refrigerator appliance where the door includes reinforcing corner brackets that structurally complete the corners of the door. The corner brackets are located at the door corners adjacent vertical and horizontal side walls of the outer door skin. The brackets structurally replace the horizontal side wall immediately adjacent the vertical side wall with a thicker, stronger material, such as, for example, metal or steel, so that loading normally transferred to the outer door skin through the horizontal side wall at this corner location is instead transferred directly to the brackets mounted in the door. In the preferred embodiment, the horizontal side wall has an open section that is formed as cut-out section located adjacent where the door is normally mounted through hinge pins to the refrigerator appliance. It should be understood that this open section may be formed by rolling the vertical wall around a larger arc to result in an opening. 
     In accordance with an aspect of the present invention there is provided a door for a refrigerator appliance comprising an outer door panel having an outer skin sheet with rearwardly extending peripheral vertical and horizontal side walls. The door panel has a plurality of corners positioned between adjacent horizontal and vertical side walls. The door has an inner door liner secured to the outer door panel spaced from the sheet to define a cavity between the inner liner and the sheet. The door has reinforcing corner brackets positioned within the cavity adjacent at least two opposed corners located at ends of one of the vertical side walls. The brackets extend along and are secured to at least one of the horizontal and vertical side walls adjacent the vertically opposed corners to reinforce the corners. The door includes an elongate supporting strut having its opposing ends engaging the reinforcing corner brackets. The strut extends adjacent the one vertical side wall to support the corner brackets within the door to reinforce the door. 
     The corner bracket preferably is a plate that extends across the open or cut-out section of the horizontal wall and adjacent the horizontal wall for securement therewith. The bracket has a depending end peripheral flange that extends towards the cavity and abuts the adjacent vertical side wall. The bracket plate and depending end peripheral flange are crimped to the side walls to secure the bracket at the corner. 
     Preferably, the brackets include a central opening adjacent the removed horizontal side wall section for receiving a hinge pin and the strut is a hollow metal tube having and end peripheral rim secured to the bracket adjacent the central opening. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the nature and objects of the present invention reference may be had to the following detailed description when taken in conjunction with the accompanying diagrammatic drawings wherein: 
     FIG. 1 is a perspective view of a top mount refrigerator appliance having top and bottom doors constructed in accordance with the present invention; 
     FIG. 2 is a sectional view taken at lines  2 — 2  of FIG. 1 showing the construction for a refrigerator door; 
     FIG. 3 is a perspective partially exploded view showing the outer door skin from an inside view with the corner reinforcing brackets assembled and the reinforcing tubes about to be assembled; 
     FIG. 4 is a perspective view of the lower left hand bracket shown in FIG. 3 relative to the side wall of the outer door skin; 
     FIG. 5 is an exploded view of the door corner construction and epaulet; 
     FIG. 6 is a front view looking up at the epaulet shown in FIG. 5; 
     FIG. 6A is a side elevational view of the epaulet of FIG. 6; and 
     FIGS. 7 and 7 a  are sectional views showing the assembly of the corner reinforcement bracket and the epaulet for the refrigerator respectively at corners having a hinge pin and mounting cap. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Referring to FIG. 1 there is shown a refrigerator  10  comprising a cabinet  12 , a top door  14  and a lower door  16 . Each of doors  14  and  16  are shown in a closed position and in the preferred embodiment have a width of 30 inches or larger. The top door  14  is typically adapted to close the freezer food compartment  18  and the lower door  16  typically closes the fresh food compartment  20 . Of course it is understood that the position of the freezer compartment  18  relative to the fresh food compartment  20  could be reversed as in a bottom mount refrigerator, or alternatively, the invention has application in side-by-side refrigerator doors. However, in accordance with the present invention, the preferred refrigerator construction is that shown having doors  14  and  16  respectively closing the upper and lower food compartments  18  and  20 . 
     In FIGS. 1 to  3  the construction of door  16  is shown. Door  16  has an outer metal panel  22 . Door panel  22  has a sheet or an outer skin  24  with upstanding or rearwardly extending curved vertical side walls  26  and flat horizontal side walls  27 . The vertical side walls  26  and horizontal side walls  27  extend towards each other and would normally meet at corners  29 . However, a cut-out or open section  64  is cut out from the horizontal side wall  27  at the corner  29  so that the horizontal side wall does not meet or join the vertical side wall  26 . The vertical and horizontal side walls  26 ,  27  each further include in-turned flanges  28  that preferably extend parallel to the sheet  24  and overlap at the corners  29 . 
     Mounted on top of the in-turned flanges  28  of the door panel  22  is a inner door liner  30  of preferably plastic material. Liner  30  is spaced from the generally flat sheet  24  of the outer door panel  22  to define a cavity  32 . The liner  30  has dyke side walls  36  and an interior vertical wall  38 . Shelf supports  41  are integrally molded to walls  36  and  38 . The shelf supports  41  carry shelves  43  which in turn carry articles (not shown). The liner  30  includes a peripheral edge or flange  44  secured by suitable screw fasteners (not shown) to the in-turned flanges  28  of the outer door panel  22 . Mounted over the liner flange  44  and door panel flange  28  is a gasket  47  which seals the door in an airtight fashion with the refrigerator appliance  10 . Foamed insulation  48  fills the cavity or space  32  defined between the liner  30  and the outer panel  22 . 
     The refrigerator door  16  as shown in FIGS. 3 through 7 has two unique features. The first unique feature resides in the use of brackets  60 , positioned at opposing corners  29 , and the reinforcing tube  83  that extends between the brackets  60  supporting the brackets  60  in the door cavity  32 . This feature improves the rigidity of the door  16  by providing localized corner reinforcement adjacent the vertical side walls  26  of the refrigerator door  16 . By using the bracket  60  and tube  83  in combination with the cut-out section  64  of the horizontal side wall  27 , the stresses associated with loading hinge pins  92  of the refrigerator door  16  are distributed through the bracket  60  and are not distributed directly to the outer skin  22 . Such direct distribution of force could otherwise cause large heavy doors  16  to warp over extended periods of use. The second unique feature relates to use of an epaulet cover  110  that covers exposed edges of the door corner  29 . The epaulet cover  110  covers the exposed edges and effectively joins the side walls of the door corner  29  eliminating the need for welding these side walls to each other at the corner  29 . The epaulet cover  110  also compensates for and hides manufacturing imperfections at the door corners  29 . The epaulet further improves the visual appearance of the door corners by smoothing the corners and eliminating the visual gap between the epaulet wall and door side walls. 
     Referring to FIGS. 3 to  5 ,  7  and  7   a,  the reinforcing corner brackets  60  are shown positioned within the cavity  32  adjacent to the corners  29 . Each bracket  60  comprises a plate  62  that extends across a removed or cut-out section  64  from the horizontal wall  27  at the corner  29  adjacent the vertical side wall  26 . The width of the bracket  60  is chosen to be substantially the width of the door  16  adjacent the horizontal wall  27  so that the bracket snugly fits into the door corners  29 . 
     The cut-out section  64  of the horizontal side wall  27  leaves exposed peripheral edges  66 ,  66   a,    66   b,    66   c  respectively extending along the outer door skin  24 , the curved vertical side wall  26 , the in-turned flanges  28 , and along the horizontal side wall  27 . The exposes edge  66 ,  66   a,    66   b,    66   c  and the removed section  64  can best be seen in FIG.  5 . 
     The bracket plate  62  has a first portion  68  which extends in abutting relation adjacent the horizontal side wall  27 . The corner bracket further includes a load bearing surface portion  70  that is recessed in spaced relation from the horizontal wall  27 . The load-bearing portion  70  extends across the removed horizontal wall section  64  to engage in abutting relation the inside surface  71  of the vertical side wall  26 . 
     The bracket plate  60  includes opposite side flanges  72  and an end flange  74  which depend from the bracket plate  60  towards the interior cavity  133  of the door. The opposite side flanges  72  respectively abut inside surfaces of the outer door skin  24  and the in-turned flange portions  28  associated with the horizontal side walls  27 . These in-turned flange portions  28  are also vertically extending side walls. The opposite side flanges  72  and the first portion  68  are crimped at  77  by a crimping tool to engage the horizontal side wall  27  and the in-turned flange  28  in a tag and lock fastening arrangement. 
     The load bearing portion  70  of the bracket member  60  further includes a dependent ring or rim  80 . The reinforcing tube  83 , preferably metal, has opposed flared ends  85  placed around and engaging rim  80  of the load bearing bracket portion  70  of the bracket member  60 . The rim  80  defines a first central opening  87  into which a plastic thimble  84  is inserted in interference fit into the flared ends  85  of the metal tube  83 . The thimble  84  has a shaft  86  in interference fit with the metal tube  83 . The thimble  84  includes an out-turned head portion  88  which rests on the recessed load bearing surface portion  70  of the bracket member  60 . Mounted within the hollow thimble  84  is either an end cap  90  (FIG. 7A) or a hinge pin  92  (FIG.  7 ). Hinge pin  92  is shown to have a central portion  97  which is of a greater diameter than the diametrically opposed hinge pins  98 . The diametrically opposed hinge pins  98  may be hollow to allow for the insertion or passage of conduit or wire along the metal tube between doors. The hinge pin central has threads  94  threadably mounted to a hinge bracket  95  mounted to the refrigerator cabinet. The hinge pin  92  is a central hinge pin for supporting doors  14  and  16 . Alternatively, hinge pin  92  could be a lower hinge pin or an upper hinge pin depending on its location. 
     The door tube  83  is typically foamed in place within the door to rigidly locate the opposing corner brackets  60  between the ends of the rigid tube  83 . The door corner reinforcing bracket  60  and metal tube  83  co-operate to reinforce the door corners  29  along the vertical side walls  26  of the refrigerator door  16  and to bear the load associated with the loading of the door  16  onto the hinge pin  92 . The bracket reduces the load transferred from the hinge pin  92  directly onto the horizontal side wall  27  and the outer door skin  24 . Consequently, the stresses and strains associated with door loading are not directly transferred from the area of the hinge pin  92  onto the outer skin  24  of the door  16 . The reduction in the transference of these stresses and the additional reinforcement provided by the metal bracket member  60  and the reinforcing metal tube  83  further rigidizes the door. 
     In order to assist in venting of gases from the door during the foaming of insulation into the door  16 , the horizontal portion  68  of the bracket member  60  extending adjacent the horizontal side wall  27  has a recess or opening  104 . Opening  104  is located adjacent a corresponding opening in the horizontal side wall  27 . Recess opening  104  is covered with a vent tape  106  which allows gases to escape through the wall  27  and yet prevents the escape of foam. The opening  104  is closed by cap  108  which is shown in FIGS. 7 and 7A secured by interference fit through the horizontal side wall  27  and the horizontal extending bracket portion  68 . 
     Referring to FIGS. 5 through 7A, the epaulet  110  used to cover the cut-out section  64  to complete the door  16  construction is shown. The epaulet  110  has a relatively flat and smooth outer surface  112  having a circular central recess  114  through which the thimble  84  passes. The epaulet  110  has a beveled corner  116  from which depends downwardly or rearwardly a peripheral flange  118 . 
     As shown in FIG. 5, the epaulet  110  is positioned over the cut out section  64  such that a flange  118  overlaps outside surface portions of the side wall  26 , outer skin  24 , and the in-turned flange at  28  of the door. The epaulet cover  110  further has a portion  112  that is adapted to overlay a portion of the horizontal side wall  27 . 
     As best seen in FIGS. 6,  7  and  7 A, a bottom surface  122  of the epaulet cover  110  has a series of first fasteners or ribs  124 . The ribs  124  are spaced a distance from the flange  118  that is equal to or slightly less than the thickness of the metal used in the outer door panel  22 . The ribs  124  are adapted to engage inside surface  71  of the vertical sidewall  26  and an inside portion of the other door skin  24 . 
     Thus, as the epaulet cover  110  is inserted onto the horizontal side wall  27  over the cut-out section  64 , the ribs  124  co-operate with the depending flange  118  to tightly secure the epaulet cover  110  over the exposed edges  66 ,  66   a,  and  66   b.  The epaulet cover also overlays a portion of the horizontal side wall  27  covering the exposed edge  66   c.    
     As of the epaulet cover  110 , is moved into the position covering the cut-out section  66 , second fasteners or extensions  124  depending from the underside of the epaulet cover  110  pass through slotted apertures  128  located in the recessed load bearing surface portion  70  of the bracket  60 . The extensions  124  of the epaulet cover  110  have hooks  126  that engage the under surface of the bracket  60  preventing of the epaulet cover  110  from being pulled away from the bracket  60 . The slotted apertures  128  have a width of that is larger than the width of the extensions  124  so that relative lateral movement of the epaulet cover  110  with respect to the bracket  60  may occur in the longitudinal direction of the horizontal side wall  27 . 
     As best shown in FIGS. 6,  7  and  7 A, epaulet cover  110  has a depending circular rim  130  that rests on the recessed load bearing surface  70  of bracket  60 . The opening  114  within the rim  130  is aligned with the opening  87  of the bracket  60  and the opening  114  is slightly larger in diameter than the opening  87  of the bracket  60 . As a result the rim  130  defines an opening  87  that is adapted to receive hinge pin  92  in a manner that the hinge pin  92  does not translate any loading door forces onto the epaulet cover  110 . Hinge pin  92  loads the thimble  84  by resting on the head  88  of the thimble  84  which in turn rests on the recessed load bearing surface  70 . The head  88  of thimble  84  is spaced from the rim  130  and does not touch the rim  130 . Hence loading of the thimble  84  is not translated onto the epaulet cover  110 . The thimble  84  through its interference engagement with a the tube  83  supports the hinge pin  92  relative to the tube  83  with minimal loading of the bracket  60  and with substantially no loading of the epaulet cover  110 . This reduces stresses or loads associated with supporting the door  16  to the refrigerator through the hinge pin  90  from being distributed over the other door skin  24  of the door panel  22 . 
     In FIG. 7 a,  a cap  90  replaces pin  92 . This permits the opposed vertical sides of the door  16  to be structurally symmetrical with one side of the door pivotally mounted to the cabinet and the other side of the door capped. 
     As is apparent from the foregoing disclosure, various other embodiments and alterations and modifications which may differ from the embodiments disclosed may be readily apparent to one skilled in the art. It should be understood that the scope of the patent shall be defined by the claims and those embodiments which come within the scope of the claims that follow.