Patent Publication Number: US-4319629-A

Title: Constant temperature box

Description:
This is a division of application Ser. No. 32,868 filed Apr. 24, 1979, now abandoned. 
    
    
     This invention relates to a constant temperature box, and more particularly to a portable constant temperature box which keeps its interior at constant temperature by means of a cooling or heating source, so that cold foodstuffs and beverages, such as fruits, canned beer or fish, can be kept cold within the box and warm foodstuffs such as lunches or tea, can be kept warm. 
     Generally a cooler or ice-box for preserving cold to cool foodstuffs and beverages kept therein is known as a constant temperature box, such as a thermal jar, of adiabatic construction having two thin walls of glass with a vacuum therebetween, for keeping the contents cold or warm. 
     The cooler comprises a body and a lid of insulating material, such as polyurethane. The lid closes tight against the body, thereby forming an adiabatic. The cooler is usually charged with ice together with foodstuffs and beverages so that the ice, as a cooling source, may keep the foodstuffs and beverages cold. 
     Of course, the ice within the cooler eventually melts to collect at the bottom of the cooler and undesirably interacts with the cooler contents. This interaction is particularly undesirable when the cooler contains fish as the latter readily discolor or deteriorate when in contact with water. 
     The constant temperature box has a higher adiabitic effect than the cooler, so that foodstuffs and beverages within the box are kept cold or warm for a long period. The box, however, is complex in construction and expensive to produce because a large-sized box is required to accomodate a large amount of foodstuffs and beverages. Moreover, the glass walls of the constant temperature box are breakable. 
     The present invention has been designed to overcome these problems. Thus, an object of the invention is to provide a constant temperature box which is, on the one hand, simple in construction; inexpensive to produce and unbreakable even with rough handling, and, on the other hand capable of positively preserving the cold or heat therein without affecting the quality of foodstuffs and beverages, thereby keeping them at constant temperature for a long period. 
     The invention incorporates a liquid container of a cooling or heating source within a constant temperature box comprising a body having an upper opening and a lid closing tight the upper opening, which are both of adiabatic construction. The container is made flat and arranged to abut against the side walls of the box body, to cool or warm the foodstuffs and beverages kept within the box. 
     The cooling or heating source container is hollow and hermetically sealed and is filled with a liquid which serves as the cooling or heating source. The container is nearly equal in width to an interval between two opposite side walls of the body, nearly equal in height to the body and small in thickness, thus being flat as a whole. The cooling or heating source container also has an intake for liquid and a stopper closing the intake. 
     The cooling or heating source container is formed of a heat-resistant, heat transferrable material, such as synthetic resin or aluminum alloy. 
     The liquid within the container is generally water. The container can be filled with water and closed by the stopper and then put into a refrigerator to freeze the water for subsequent use as a cooling source. On the other hand, the container can be filled with water preheated to a high temperature for use as the heating source. 
     The cooling or heating source container constructed as described is fit into the box body upright to abut against side walls thereof so that cold or warm air may be derived from the cooling or heating source and circulated by convection within the box to cool or warm foodstuffs and beverages wholly by convection and by conduction from direct contact with the container, thus collectively improving the cooling or heating effect. 
    
    
     These and other objects and novel features of the invention will be more apparent from the following detailed description taken in accordance with the accompanying drawings, in which 
     FIG. 1 is a perspective view of a constant temperature box of an embodiment of the invention with its lid open, 
     FIG. 2 is a longitudinally sectional view of the constant temperature box with its lid closed, 
     FIG. 3 is a longitudinally sectional view of a modified embodiment of the invention, and 
     FIG. 4 is a perspective view of another modified embodiment showing a cooling or heating source container. 
    
    
     A constant temperature box of the invention, as shown in FIG. 1, comprises an upwardly opening body 1 having therein a space for containing foodstuffs and beverages, a lid 2 closing the upper opening of the body 1, and a cooling or heating source container 3 incorporated within the box body 1. 
     The box body 1, as shown in FIG. 2, comprises an inner body 11 of stainless steel, an outer body 12 of synthetic resin, and insulating material 13, such as polyurethane or foaming sterol resin, inserted between the inner and outer bodies 11 and 12. The body 1 is formed of four opposite side walls 14a to 14d and a bottom 14e and opens upwardly. 
     The lid 2 is of a shallow dish-like shape and comprises an inner and outer bodies 21 and 22 of synthetic resin and insulating material 23 inserted therebetween. The lid 2 is connected with the upper edge of one side wall 14c by hinges 4 to permit opening and closing of the box and is surrounded at the lower edge with packing 5 to contact with the upper edge of body 1 for tightly closing the interior of the box. 
     Between the lid 2 and the body 1 are provided clasps 6 for tightly holding them together, and at the body 1 is provided band holders 8 through which a band 7 is inserted for the convenience of carrying the constant temperature box. 
     The cooling or heating source container 3 comprises a hollow hermetically sealed box, which is chargeable with liquid, the liquid serves as the cooling or heating source. The container 3, as shown in FIGS. 1 and 2, is about equal in width to an interval between opposite side walls 14a and 14c, nearly equal in height to the box body 1 and small in thickness and takes a generally wall like shape. At the upper wall of container 3 are provided an intake 31 for the liquid and a stopper 32 for closing the intake 31. The cooling or heating source container 3 is formed of a heat resistant synthetic resin and/or aluminum alloy which is capable of transferring heat or cold to the box interior. 
     When used as a cooling source, the container 3 is filled with water through the intake 31, and the water is frozen by, for example, a domestic refrigerator. When used as a heating source, the container 3 is similarly charged with hot water preheated to a high temperature. 
     The cooling or heating source container 3 is fit into the constant temperature box opposite sidewalls 14c and 14d and is supported upright by supporting means hereinafter described. 
     The supporting means comprises a pair of strip projections provided at the inner surfaces of a pair of opposite side walls 14a and 14c and extending vertically thereof. The strip projections 15 as shown in FIGS. 1 and 2, are each positioned at the walls 14a and 14c close to the side wall 14b whereby the strips 15 and the side wall 14b support the container 3 upright, with the container abutting against the inner surface of wall 14b. 
     In addition, the supporting means may comprise two pairs of projections 15 which are so arranged that each pair is spaced at an interval coincident with thickness of the container 3 so that the container 3 may be inserted just between the projections 15. In this instance, the container 3 is width-wise supported at the intermediate portions of side walls 14a and 14c. 
     The strip projections 15 also may be provided at the side walls 14b and 14d in place of those 14a and 14c, in which case the container 3 is formed in a size coincident with that of the wall 14a or 14c. 
     The constant temperature box of the invention constituted as aforegoing, is used in such a manner that the cooling or heating source container 3 is previously charged with water and put into a freezer to thereby freeze the water, or charged with hot water, and then the container 3 is placed in the box body 1 and supported by the supporting means. Hence, the interior of body is kept cold or warm by air cooled or heated by the cooling or heating source and circulating by convection in the box, thereby keeping the box contents at a low or high temperature. In other words, the cooling or heating source container 3, which is inserted upright within the body 1 of constant temperature box, allows cold or warm air to circulate by convection within the box, the cold air flowing downwardly from the upper portion of container 3 and the warm air upwardly from the lower portion thereof. Hence, the constant temperature box is filled with the cold or warm air throughly and uniformly, thereby keeping cold or warm the whole box interior. In addition, the contents may directly contact with the container 3. As a result, the box contents are effectively and rapidly cooled or warmed by the air circulating by convection, and by conduction from direct conduct with the container 3. 
     As an alternative to the above embodiment employing a single cooling or heating source container, two or more such containers may be disposed along the opposite side walls 14b and 14d respectively, or along the side wall 14b and bottom 14e as shown in FIG. 3. As seen from FIG. 3, a first cooling or heating source container 3 and a second such container 3a abut against the side wall 14b and bottom 14e respectively and are connected to be foldable. 
     When the containers 3 and 3a are formed of a synthetic resin the foldable connection is formed by hinged portions 33, and when the containers 3 and 3a are formed of an aluminum alloy or the like the foldable connection is formed by hinges or flexible connectors. 
     As another alternative, four of the first cooling or heating source containers 3, 3, 3, 3 may be inserted along the four side walls 14a to 14d and combined with the second cooling and heating source container 3a laid along the bottom 14e. 
     In this instance, the first and second cooling and heating source containers 3 and 3a may be connected in a box-like shape, but it is preferable that each of the first containers 3 be separated from one another and foldably connected to the second container 3a. 
     In addition, the containers 3 through 3a are, as shown in FIG. 3, fluid connected through hinged portions 33 and communicate with each other therethrough, whereby a single intake 31 attached to one container 3 as shown in FIG. 4 is sufficient to fill all containers. 
     As clearly understood from the above description, the constant temperature box of the invention is constructed such that the cooling or heating source container is charged with a liquid mainly with water, the water being frozen for use as a cooling source or heated for use as a heating source. The container is placed into the box body and held along the inner surface of at least one side wall to thereby cool or warm the box contents by cold or warm air from the container. As a result, the container selectively and positively keeps the interior cold or warm. Hence, when the constant temperature box is used as the cooler there is no discoloration or degeneration of the contents, while, the interior of the box is as a whole kept cold by circulation of cold air and also the contents are kept cold by direct contact with the cooling source. In other words, the convection of cold air and conduction of the cold by direct contact of the contents with the cooling source, keep the contents cold, thereby highly improving the cooling effect. The box, when used for warning, has similar high heating effect. Furthermore, the supporting means supports the container to opposite side walls of the body, so that the container can be used to partition the interior of body to improve the cooling or heating effect. Also, the constant temperature box is very simple in construction and inexpensive so as to be of practical use. 
     While specific exemplary embodiments of the invention have been shown and described, the invention is not to be considered as limited thereto as numerous modifications can be made. Accordingly, the invention is to be considered as limited solely by the following claims.