Abstract:
A refrigerated cabinet for the merchandising of frozen foods is disclosed as including a lower interior freezer and an upper opened top which is provided with a peripheral mount; a frost shield carried by the mount is located in spaced relation and adjacent to walls of the freezer whereby frost accumulates on the frost shield rather than on the freezer walls.

Description:
BRIEF SUMMARY OF THE INVENTION 
     The present invention relates to refrigerated cabinets of the type having an open top portion to provide easy access to frozen foods therein. Such conventional refrigerated cabinets are faced with the problem of requiring frequent defrosting because the ambient warm air is drawn into the cabinet by the turbulence of the cold air therein; this arrangement results in frost forming on the evaporator wall of the cabinet and thus acting as an insulator to lower the temperature of the evaporator wall. 
     It is an object of the present invention to solve the frost accumulation problem of a refrigerated merchandising cabinet by retarding the frost accumulation with a frost shield. 
     It is another object of the present invention to locate a frost shield in the upper portion of a refrigerated cabinet in spaced relation to the evaporator wall of the freezer unit. 
     A further object of this invention is to maintain a frost shield and the wall of a freezer&#39;s evaporator in a refrigerator cabinet at substantially the same temperatures. 
     It is another object of this invention to stabilize the cold air in the food freezer chamber of a refrigerated cabinet. 
     The present invention has another object in that the flow of ambient warm air is reflected away from the food freezer chamber of a refrigerated cabinet. 
     It is a further object of the present invention to substantially reduce the flow of warm air into the food freezer chamber of a refrigerated cabinet. 
     The present invention is summarized in that a frost shield for a refrigerated cabinet is located adjacent the upper portion of the cabinet&#39;s food freezer chamber so that frost and/or ice will form on the frost shield and not on the evaporator wall forming the freezer chamber; the frost shield is mounted in spaced relation to the evaporator wall whereby the ambient warm air will conically rise above the freezer chamber and will not be drawn into the freezer chamber. 
     Other objects and advantages will become apparent from the following description taken in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a refrigerated cabinet for frozen foods embodying the frost shield of the present invention. 
     FIG. 2 is a fragmentary cross sectional view of a detail of FIG. 1 but shown on an enlarged scale and with the frost shield in assembled position. 
     FIG. 3 is a perspective view of a refrigerator cabinet similar to FIG. 1 but showing the cabinet to be a round tub-like configuration. 
    
    
     DETAILED DESCRIPTION 
     As is illustrated in FIG. 1, a base 10 having four casters 12 (only three being shown) defines a movable support for a refrigerated cabinet, indicated generally at 20. As is shown in FIG. 2, the refrigerated cabinet is rectangular in plan view, however, the shape may be varied to conform to particular requirements; for example, a circular cabinet 120 is shown in FIG. 3 on a circular base 110. It is to be understood that other shapes may be utilized such as triangular, square, trapezoidal, as well as irregular shapes to conform to installation requirements. 
     The refrigerated cabinet 20 has a bottom wall integrally formed with four hollow walls 22, 24, 26 and 28 perpendicular thereto so that the cabinet is open at its top. 
     The top portion of the cabinet 20 includes a generally inverted U-shaped member 30 (see FIG. 2) with a pair of vertical walls horizontally spaced from each other. One wall 32 has a lower flange 34 which may be supported on the cabinet wall 22 (24, 26 and 28) with a rubber-like bumper sealing ring 36 thereon. The second wall 38 has a stepped portion 38 which is disposed on the wall of the evaporator of the freezer unit. The inside of the stepped portion 38 defines a peripheral support for an open frame element 40. 
     It should be noted that the wall 32, the lower flange 34 and the stepped support 38 conform to the entire perimeter of the upper portion of the cabinet 20 to define the continuous perimeter of the inverted U-shaped member 30. 
     The frame 40, which defines a frost shield, is shown in FIG. 2 as includes a L-shaped ledge 42 which is supported on the inside of the stepped portion 38. A vertical wall 44 extends from the upper ledge 42 to a lower U-shaped channel 46. The components 42, 44 and 46 also conform to the entire perimeter of the upper portion of the cabinet 20. 
     While the inverted U-shaped member 30 has been described above as a separate structure supported on the cabinet 20, the member 30 may be integrally formed with the cabinet 20. In such an arrangement, the lower part of the stepped portion 38 would be integral with the evaporator wall 48. 
     The horizontal dimension of the upper ledge 42 is approximately twice that of the mating horizontal dimension of the supporting stepped portion 38. Consequently, the frame&#39;s vertical wall 44 is horizontally spaced inwardly from the lower part of the stepped portion 38 and the evaporator wall 48. In addition, it is apparent from FIG. 2 that the stepped arrangement locates the frost shield 40 slightly from the top surface U-shaped member 30. 
     The frost shield 40 may be made of any suitable material light enough to be inserted and removed by hand from the cabinet 20. In the particular arrangement shown the material utilized is a molded plastic, but other suitable materials such as metal, wood, etc. may also be utilized. 
     The refrigerated merchandiser is a conventional item available in the open market, for example, Models AS-4.5, AS-6, AS-8, AS-7, PL-3 and RD-8 manufactured by ARTIC STAR OF TEXAS in Arlington, Tex. The conventional refrigerated merchandiser includes the common items of a freezer unit, such as a 115 volt, one-half horsepower compressor, an evaporator and a thermostatic control device. 
     The frost shield&#39;s purpose is to eliminate the majority of frost and ice from accumulating on the evaporator wall of the freezer unit. This is done by placing the frost shield at the top area of the freezer. The design of the shield causes the cold air to become very stable in the freezing chamber. This is done by reflecting the warm air in an upward motion which forms a cone effect over the opening of the freezing chamber by eliminating the air turbulence. This helps in eliminating the intake of warm moist air. The location of the frost shield from the top edge of the unit and the clearance from the evaporator wall allows the frost shield to become approximately the same temperature as the evaporator wall. This allows the frost and ice to accumulate on the shield and not on the evaporator. 
     Usually a cold wall freezer needs to be defrosted at least every four to five days to make it operate effectively, because the ice and frost acts as an insulator. The frost shield allows the unit to operate at a much longer period of time, approximately two to three weeks before the frost and ice affect the temperature. The frost shield can be made either as a removable part or as a permanent part of the unit. If it is a separate part, the ice and frost can be disposed of by either tapping the frost shield and knocking the frost and ice off, or flushing it with water. If the shield is a permanent part of the unit, the ice and frost can be removed by tapping the shield with your hand, or some instrument, to break it loose from the shield and then dispose of it. 
     During operation of the above described refrigerated unit, the warmer ambient air surrounding the open top of the unit is deflected upwardly adjacent the periphery of the cabinet causing a cone effect to be formed over the freezer compartment. Thus, there is a substantial reduction of the warmer air flow into the freezer compartment and a consequential mixing with the cooler air therein whereby turbulence of the cooler air is substantially reduced. The deflector element 40 is located in the upper area of the freezer compartment and in spaced relation to adjacent vertical wall portions with the result that the ice and frost will accumulate on the deflector and not on the wall portions of the freezer compartment. 
     Inasmuch as the present invention is subject to many modifications, changes in details and reversal of parts, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.