Patent Publication Number: US-7895806-B2

Title: Interlocking wall sections for refrigerated enclosures

Description:
FIELD OF THE INVENTION 
     This invention relates generally to interlocking insulated wall sections for use in the construction of structurally sound refrigerated enclosures. 
     BACKGROUND OF THE INVENTION 
     This invention relates more specifically to interlocking wall sections that are ideally suited for use in the construction of refrigerated merchandisers having an enclosed compartment for holding products in a relatively cool or cold environment. Many prior art refrigerated enclosures of this type employ modular corner units to attach the various insulated wall pieces in assembly. This type of construction required the use of a relatively large number of parts and the joints created by the modular corners are generally difficult to align and require special insulation and a large number of mechanical fasteners to complete. In addition, this type of construction does not allow for off-line fabrication of the various wall sections as subassemblies. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to improve the structural and thermal integrity of refrigerated enclosures. 
     It is a further object of the present invention to provide for improved structural joints at the corners of insulated walls of a refrigerated enclosure. 
     A still further object of the present invention is to improve the ease of assembly of a refrigerated assembly such as refrigerated merchandiser. 
     Another object of the invention is to allow for the off-line assembly of insulated wall sections of a refrigerated container whereby the sections can be easily brought together and interlocked in place at final assembly. 
     Yet another object of the present invention is to minimize the number of parts required to assemble a refrigerated enclosure. 
     These and other objects of the invention are attained by a wall section that contains a shell having an outer panel and two end walls integral with the outer panel that are mounted perpendicular to the outer panel. A cover is mounted over the shell that has an inner panel and a first end wall and a second end wall. The first end wall of the cover is in contact with one end wall of the shell and the second end wall of the cover passes into the shell between one end wall of the shell and the other end wall of the tray. An L-shaped flange having a first leg that is connected to the distal end of the second end wall of the cover and a second leg that is mounted in contact with the other side wall of the tray. A space is established between the two wall panels, which is filled with insulation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a further better understanding of these and other objects of the invention, reference will be made to the following detailed description of the invention which is to be read in association with the accompanying drawing, wherein: 
         FIG. 1  is a perspective view of a refrigerated merchandiser employing wall sections that embody the teachings of the invention; 
         FIG. 2  is a top view in section of a wall section that embodies the present invention; 
         FIG. 3  is a section taken along lines  3 - 3  in  FIG. 1  showing a number of wall sections that embody the invention interlocked in assembly; 
         FIG. 4  is a partial top view showing a modified cover end flange; 
         FIG. 5  is also a partial top view showing a further modified cover end flange; and 
         FIG. 6  is an exploded view in perspective showing a second embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Referring initially to  FIG. 1-3  there is illustrated a refrigerated merchandiser, generally reference  10  that contains interlocking insulated wall sections which embody the teachings of the present invention. Although the present invention will be described with specific reference to a refrigerated merchandiser, it should become evident from the disclosure below that the invention has wider application and may be employed in association with any number of refrigerated enclosures requiring relatively strong insulated walls. The merchandiser includes a door  12  mounted in the front of the unit that opens into a refrigerated storage compartment for containing products such as canned and bottled beverages and other perishable or frozen consumables that necessitate storage within a controlled atmosphere. The door contains a transparent window  13  that allows a customer to view the contents of the unit without the need of opening the door. 
     The merchandiser includes a separate equipment compartment  15  that is isolated thermally from the refrigerated product compartment by means of an insulated floor panel  16 . A refrigeration system (not shown) is housed within the equipment compartment that includes an evaporator unit and a condenser unit each being equipped with its own fan and being connected by a compressor in a conventional manner to produce a flow of refrigerated air from the system&#39;s evaporator into the product compartment. Warm air discharged from the condenser unit is passed out of the equipment compartment via a vent  17  located in the lower part of the merchandiser. An access panel  18  located over the vent which can be removed to allow a technician ready access to the refrigeration equipment. 
     Turning now to  FIG. 3 , the upper part of the merchandiser contains four insulated wall sections that are interlocked together so as to provide extremely tight joints at the corners to produce a rigid structure having high thermal integrity particularly in the corner regions. The four walls include two side walls  20  and  21 , a back wall  23  which extend from the base of the unit to the top of the unit, and a front wall  24  that is foreshortened to accommodate the door and the equipment compartment access panel. Although not shown, the top of the unit is enclosed with an insulated ceiling panel. 
     Each wall section is of similar construction with the only differences being found in the height and the width of each section. 
     As illustrated in  FIG. 2 , each wall section includes a shell  30  that is enclosed by cover  31 . The shell includes an outer panel  33  and two opposed end walls  35  and  36  that are mounted perpendicular to the outer panel to create a channel shaped structure. 
     The cover  31  includes an inner panel  38  which also has two opposed end walls  39  and  40  that are mounted perpendicular to the inner panel. End wall  39  is mounted in contact with the outside surface of end wall  35  of the shell while the opposite end wall  40  of the cover passes downwardly into the shell. An L-shaped flange  43  protrudes outwardly from the end wall  40  towards the opposite end wall  36  of the shell. The flange  43  contains a first leg  44  that is connected to the distal end of end wall  40  and which rests on the floor of the shell. The second leg  45  of the flange  43  is turned outwardly and rests in contact against the inside surface of end wall  36  of the shell. With the cover so mounted upon the shell the outer and inner panels of the wall section are held in parallel alignment with a space  50  being established between the two panels. 
     The shell  30  and cover  31  of each wall section is constructed of any suitable material, such as sheet metal, structural plastic, or any other suitable composite materials. The shell  30  and cover  31  of the wall section shown in  FIG. 2  are formed from a single piece of sheet metal so that the individual sections of each are integrally joined. The end walls and the end flange each preferably extend across the entire width of the inner and outer panels, however in practice each may be broken up into a series of spaced apart segments without departing from the teachings of the present invention. When the wall sections are assembled as shown in  FIG. 3 , the cover  31  can be secured to the shell  30  using any one of well known fastening techniques such as mechanical fasteners, adhesive bonding, cladding, or pressure fits to form the desired hollow structure. Preferably, a tight sliding fit is provided between the shell  30  and the cover  31  so that the cover  31  fits snugly within the shell  30 . 
     As best illustrated, four wall sections can be interlocked at the four corners of the unit by simply inserting the unflanged end of one section into the flanged end of its neighbor. The dimension D 1  over the two panels of each wall section is substantially equal to the inside dimension D 2  of the cover flange to provide a close running fit between the two wall sections that form a corner section of the structure. This interlocking feature insures that a tight structural joint is established at the corners resulting in an overall rigid structure. 
     The space or cavity  50  within each wall section is filled with a thermal insulating material  55  which can be polyurethane foam, fiberglass sheets or any other material that is capable of providing the necessary insulation. The joint formed by the interlocking wall sections insulates the corners of the enclosure providing for a thermally efficient assembly. 
     Turning now to  FIG. 4 , there is illustrated a further embodiment of the invention wherein the end flange  43  of the cover is provided with a stiffening plate  60  that is mounted within the corner that is established between the two legs of the end flange. The stiffening plate is mounted at a 45° between the legs and extends substantially along the width of the cover. As noted above, the cover provides a tight running fit between the two end walls of the shell in assembly and the stiffening plate serves to furnish greater rigidity to the structure which helps prevent the cover from being dislodged once it is closed. 
       FIG. 5  illustrates another embodiment of the invention wherein a detent  62  is established between the end flange  43  and the end wall  36  of the shell. The detent is formed by producing an outwardly protruding dimple  64  in the leg  45  of the flange adjacent to the flange corner and producing a complementary concave section  65  in the end wall  36 . In this arrangement, the cover can be either snap fitted downwardly into the shell or moved laterally into the shell with the dimple of the flange in sliding relationship with the concave section of the end wall  36 . The detent joint formed between the shell and the cover allows the cover to be more securely closed. 
       FIG. 6  is an exploded view of a wall section  70  that includes a shell  71  and a cover  72  as described above that are capable of closing together to establish a space between the shell panel  73  and the cover panel  74  for containing insulation. The wall section  70  is provided with two side caps  76  and  77  that can be snap fitted over open sides of the wall section assembly and secured in place using any suitable fastening means. One or both side caps are provided with a series of injection ports  79 - 79  through which an insulating foam material can be passed into the space between the cover panel and the shell panel. 
     While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.