1. Field of the Invention
The present invention pertains to food and/or beverage receptacles. More specifically, the present invention pertains to receptacles for containing food and/or beverages and maintaining the same at reduced temperatures.
2. Description of Prior Art
Many foods must be refrigerated or kept below a certain temperature to prevent spoilage or contamination. This is a particularly important problem which must be addressed in restaurants or other food facilities. In fact, various health laws and regulations require that certain foods be stored and/or maintained below specified temperatures.
In some facilities, various foods may be contained in receptacles which are surrounded by ice. There are a number of problems associated with this procedure. Ice melts quickly and must be constantly replenished. Disposal of the water from melted ice is messy and time consuming. The handling of ice and melted water around foods may also result in contamination of the food.
In an effort to avoid the problems associated with surrounding melting ice and water, food and/or beverage receptacles have been developed in which the ice and/or water is isolated in an enclosed space surrounding the food receptacle. Examples of some of the earlier developments in this area may be seen in U. S. Pat. Nos. 1,519,034; 1,771,186; 2,526,165; and 2,622,415.
In latter developments, food containers have been developed which not only provide a surrounding enclosed space for some type of refrigerant but also provide additional insulating or heat transfer characteristics. For example, one wall of the container of U.S. Pat. No. 3,394,562, which is of aluminum, is coated with plastic. In U.S. Pat. No. 3,715,895, the enclosed space surrounding the receptacle is filled with a refreezable aqueous refrigerant which has a freezing point substantially below the freezing point of water, e. g. propylene glycol. Other containers depend on specific insulating or sealing characteristics. See U. S. Pat. Nos. 3,755,030 and 4,789,073.
Thus, the search continues for cooling food containers which will maintain food and/or beverages at reduced temperatures for relatively long periods of time and which are easy to use, clean and maintain. Containers which are portable and relatively inexpensive are particularly desired.