Abstract:
A refrigerated case has a base and a number of supports extending upward from the base. A number of structural uprights are coupled to the supports. At least one insulated panel is positioned between the uprights and the supports and is secured to the uprights and the supports. A refrigeration apparatus is positioned to cool an interior of the case. At least the first of the panels has front and rear liner sheets. A transversely extending polymeric layer is at least partially between the liner sheets. An insulative foam layer is between the front and rear liner sheets. A number of fasteners secure at least some of the supports to the polymeric member and at least some of the uprights to the polymeric member.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to refrigerator cases. More particularly, the invention relates to structural integration of insulated panels in walls of such cases. 
         [0002]    Refrigerator cases (generically including freezers) are used in a variety of commercial situations. One key use is for retail display and vending. Many such cases include a closed rear wall and either an open front or a glass door front. 
         [0003]    Insulation of the compartment of such cases relative to their external structure is important for a number of reasons. In addition to basic efficiency concerns, insulation may be appropriate to avoid or control condensation on components external to the compartment. This may be motivated by sanitary considerations in addition to refrigerator case longevity. 
         [0004]    In refrigerator case engineering and manufacturing, modularity has been a relevant consideration. It is advantageous to be able to use at least some of the same components when producing a variety of sizes and/or configurations of case. Configurations have been developed that include combinations of external and internal structural components. These components can be coupled to each other through insulated panels. An exemplary configuration is shown in U.S. Pat. No. 5,517,826. In that patent, one or more insulated panels intervene between external and internal structural members. Studded dog bone-shaped mounting elements are embedded within the foam panels with the studs protruding from surfaces of the panels. The studs may be engaged to internal and external structural members to structurally couple such members. 
       SUMMARY OF THE INVENTION 
       [0005]    Accordingly, one aspect of the invention involves a refrigerated case having a base and a number of supports extending upward from the base. A number of structural uprights are coupled to the supports. At least one insulated panel is positioned between the uprights and the supports and is secured to the uprights and the supports. A refrigeration apparatus is positioned to cool an interior of the case. At least the first of the panels has front and rear liner sheets. A transversely extending polymeric layer is at least partially between the liner sheets. An insulative foam layer is between the front and rear liner sheets. A number of fasteners secure at least some of the supports to the polymeric member and at least some of the uprights to the polymeric member. 
         [0006]    The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a view of a refrigerator case. 
           [0008]      FIG. 2  is a partially schematic side sectional view of the case of  FIG. 1 . 
           [0009]      FIG. 3  is a transverse horizontal sectional view of the case of  FIG. 2 . 
           [0010]      FIG. 4  is a back view of the case of  FIG. 1 . 
           [0011]      FIG. 5  is an enlarged view of an insulated panel junction of the case of  FIG. 2 . 
           [0012]      FIG. 6  is an exploded view of an insulated panel. 
           [0013]      FIG. 7  is a partially schematic side sectional view of an alternative refrigerator case. 
       
    
    
       [0014]    Like reference numbers and designations in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0015]      FIG. 1  shows a refrigerator case  20  having a front  22 , a back  24 , and left and right ends  26  and  28 . For purposes of reference, front, back, left, and right, are taken from the point of view of the case itself rather than a user facing the case. The case includes a base structure  30 , a rear wall structure  32 , and a top structure  34 . The case has a cooled interior volume or compartment  36 . The exemplary case has a series of vertical groups of shelves  38 . The exemplary case is a closed case having a sliding or hinged glass door front structure  40  and patch end or partition structures  42  and  44 . Partitions are used where cases are arrayed side-by-side; patch ends are used at the two ends of the array. Alternative cases are open-front. 
         [0016]    The exemplary base  30  includes front and back transverse rails  50  and  52  for supporting the remainder of the base and, therethrough, the remainder of the case atop a ground/floor surface. The exemplary base  30  contains the refrigeration equipment (e.g., an evaporator, and the like shown schematically as  60  in  FIG. 2 ). The evaporator may be connected to a central compressor and condenser elsewhere in the facility. Alternatively, the case equipment could be self-contained.  FIG. 2  further schematically shows an air flowpath having a first portion  510  carrying cooled air from the equipment  60  to a rear air flowpath section or duct  62 . A second portion  512  flows upward through the rear duct  62 . A third portion  514  flows forward from the top of rear duct  62  through a top duct  64 . A fourth portion  516  exits the top duct near the forward end of the top  34  and is discharged downward along the front  22 . A return portion  518  is drawn back into the equipment  60  through a grate  66  near the forward top portion of the base  30  immediately in front of a base cover member  68 . 
         [0017]      FIG. 3  shows further details of the rear duct  62 . The duct  62  is segmented by a series of interior uprights including a left upright  70 , a right upright  72 , and a series of intermediate uprights  74 . Forwardly, the duct segments are each bounded by an associated duct panel  80  (e.g., mounted by fasteners  81  to side portions of forward flanges  82  of the adjacent two uprights). As is discussed in further detail below, each shelf  38  may be mounted to these uprights (e.g., a single width shelf spanning and mounted to exactly two adjacent such uprights via mounting apertures in root portions of the flanges  82 ). Rearwardly, the duct segments are collectively bounded by the forward surfaces of panels of an insulated panel assembly  84 .  FIG. 2  shows the panel assembly  84  as including an upper panel  86  and a lower panel  88 . 
         [0018]      FIGS. 2 and 3  further show the base  30  as including a series of support brackets or braces  90  extending front-to-back spanning the rails  50  and  52 . Mounted to and extending upward from a rear end portion of each brace  90  is a rear external support  92 . Each support  92  has a lower end  94  mounted to the rear end portion  96  of the associated brace  90  and has an upper end  98 . As is discussed in further detail below, the panel assembly  84  is sandwiched between the uprights  70 ,  72 , and  74  along the front and the supports  92  along the rear. 
         [0019]    It is advantageous to structurally couple the supports  90  to the uprights  70 ,  72 , and  74  so that the supports can maintain the uprights vertical against torque and resultant bending associated with the cantilevering of loaded shelves  38 . Advantageously, however, the coupling limits heat transmission from the supports to the uprights or otherwise through the panel assembly  84 . 
         [0020]      FIG. 5  shows the upper panel  86  as including an insert  100  along a lower edge  102 . The insert  100  is of a relatively rigid polymeric material (e.g., cellular PVC) between fore and aft face sheets  104  and  106  (described further below). The panel  86  includes a foam core  108  (e.g., of expanded polyurethane). Fasteners  110  and  112  respectively secure the uprights and the braces to the insert  100 . The relative rigidity of the insert  100  is effective to maintain engagement with the fasteners and transmit force between the uprights and braces. Exemplary fasteners are screws such as self-boring/drilling, self-tapping sheet metal-type screws. The exemplary insert  100  may be manufactured by the Celuka process. The exemplary insert  100  has a cross-section generally rectangular (e.g., with rounded corners) with its longer dimension between the sheets  104  and  106 . Along the inboard of the long sides is a central recess  114 . The recess  114  serves to provide increased surface area to promote adhesion and mechanical interlocking of the core  108  to the insert  100 . In the exemplary embodiment, the other long side is substantially unrecessed. 
         [0021]      FIG. 3  shows the left  70  and right  72  uprights as approximately inwardly-open C-sectioned members having a single fastener  110  extending through their rear flanges  120 . Exemplary intermediate uprights  74  are generally I-sectioned, having a pair of screws  110  extending through a rear flange  122  generally on opposite sides of a central web or leg  124 . The supports  92  have a generally rearwardly-open C-section and each have a pair of the screws  112  extending through their central forward web/leg  126 . Other sheet metal screws  127  ( FIG. 4 ) may each extend into one of the panel face sheets from either the uprights  74  or supports  92 . The exemplary uprights and supports are out of phase so that each upright is transversely offset from the adjacent supports (or vice versa). As noted above, the transverse upright spacing may correspond to a shelf width/pitch. The exemplary uprights, supports, and braces are unitarily formed of a metal such as steel. 
         [0022]      FIG. 6  shows further details of the exemplary panel  86 . The panel  86  and its sheets  106  and  104  have a common length L and height H. The exemplary L is greater than H. Exemplary H values are 0.8-1.0 m. As is discussed below, exemplary L values are 1.5-4.0 m. Exemplary thickness T ( FIG. 5 ) is 4-6 cm. Exemplary sheet thickness (not shown) is 1.0 mm or less. 
         [0023]    Opposite the insert  100  along the panel upper edge are a pair of end-to-end aligned insert strips  130  and  132 . Along the left and right edges of the panel between the insert  100  and the insert strips  130  and  132  are lateral edge insert strips  134  and  136 . The exemplary insert strips have a rectangular section elongate between the sheets and are formed of a polystyrene foam. The strips and insert  100  may be assembled to the sheets by applying adhesive between the strips and insert and the inboard faces of the sheets adjacent the perimeter of each sheet. This may leave an empty interior volume between the sheets. A gap may be left between the strips  130  and  132  through which the barrel of a foam gun may be inserted. As the foam is introduced through the gun, the gun may be swept to allow the foam to completely fill the interior space to form the core  108  upon hardening. A filler block  138  may then be inserted into the gap and secured by adhesive. In alternative embodiments, one or more holes may be drilled in the insert and/or strips through which one or more guns are inserted to introduce the foam. 
         [0024]    The lower panel  88  may be identical to the upper panel  86 . This may be so even if no fasteners are secured through the insert  100  of the lower panel. This use of the lower panel may be justified by economy of scale manufacturing considerations. Alternatively, in the lower panel  88 , the strip  100  may be replaced by one or more polystyrene foam strips (e.g., identical to the strips  130 ,  132 , and block  138  for similar economies of scale). In the exemplary embodiment, the strip  130  is shown shorter than the strip  132 . This is merely another artifact of economy of scale manufacture. By providing strips of two different lengths, different combinations of such strips may be used to assembly panels of different lengths. For example, the panel length may be associated with the length of two of the shorter strips, two of the longer strips, or one of either strip. With such permutations, the block  138  may serve to facilitate panel length not exactly the length of a given strip or combination. 
         [0025]      FIG. 7  shows an alternate configuration of a case  200  wherein the supports  202  are substantially full height. For greater structural integrity, the upper panel  86  is flipped (relative to its use in the case  20 ) so that the insert  100  falls along the upper edge. Fasteners may secure the uprights and supports to the insert as previously discussed. 
         [0026]    One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the foregoing teachings may be applied in the reengineering of an existing case configuration. In such a reengineering, details of the existing configuration will influence or dictate details of any particular implementation. Accordingly, other embodiments are within the scope of the following claims.