Insulated barbeque unit
BACKGROUND OF THE INVENTION 
     This invention relates to an insulated barbeque unit. Various types of folding barbeque untis have been utilized, and many of these have included a painted design on the outer surface thereof. The painted design may be utilized for advertising or for mere decoration. 
     One problem encountered with these units is that after extended use the heat from the charcoal within the unit causes the paint on the exterior of the unit to be peeled and to come off. This makes the unit less desirable from the standpoint of either decorating the exterior surface or from the standpoint of using the exterior surface for advertising. 
     Therefore, a primary object of the present invention is the provision of an improved barbeque unit having insulated walls therein. 
     A further object of the present invention is the provision of an insulated barbeque unit which provides the maximum insulation at the point where the maximum heat is located during the time the barbeque unit is being used. 
     A further object of the present invention is the provision of a barbeque unit which can be easily folded and carried. 
     A further object of the present invention is the provision of an improved barbeque unit which can be folded into an attractive shape that can be painted on the exterior for advertising or decoration. 
     A further object of the present invention is the provision of a barbeque unit which includes foldable legs which may be stored within the unit for transporting the unit, and which may be folded outwardly to support the unit when in use. 
     A further object of the present invention is the provision of a barbeque unit which is economical to manufacture, durable in use, and efficient in operation. 
     SUMMARY OF THE INVENTION 
     The present invention utilizes a pair of half rectangular boxes which are hinged along one of their edges so they can fold from an open position wherein their upper surfaces form a continuous plane to a closed position wherein their upper surfaces are in facing relation and the two half boxes together combine to form an enclosed rectangular box. 
     The walls of the present invention are of double thickness, including an inner wall and an outer wall which are separated by an insulative layer. In cross section, the insulative layer is thickest at the bottom, and tapers inwardly to a point adjacent the upper edges of the box side walls. Since the charcoal within the unit rests on the bottom wall of the device, the maximum insulation is applied at the point where the maximum heat is encountered. The insulative material protects the outer surface of the device from the heat of the charcoal within so that the paint on the outer surface will not become peeled, blackened or blistered due to the heat from the inside. 
     The ends of the two half boxes are each provided with vent openings. Folding legs are also mounted on the end walls of the device, and are adapted to unfold to a position wherein they support the two box halves on a supporting surface when the box halves are opened to their open position. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS 
     FIG. 1 is a perspective view of the present invention in its folded condition. 
     FIG. 2 is a perspective view of the present invention in its unfolded operative position. 
     FIG. 3 is a sectional view taken along line 3--3 of FIG. 2. 
     FIG. 4 is a sectional view taken along line 4--4 of FIG. 3. 
     FIG. 5 is a sectional view taken along line 5--5 of FIG. 3. 
     FIG. 6 is a sectional view taken along line 6--6 of FIG. 4. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The numeral 10 generally refers to the barbeque grill of the present invention. Grill 10 comprises a first box half 12 and a second box half 14. Box halves 12 and 14 are substantially identical in construction and include an inner wall 16, an outer wall 18, end walls 20, 22, foldable legs 24, 26, and a grill 28. Outer wall 18 includes a bottom portion 30 and two vertical portions 32, 34, each of which terminate in an upper edge 36, 38 respectively. 
     Inner wall 16 comprises a bottom portion 40, and vertical portions 42, 44, each of which terminate in upper edges 46, 48, respectively, which are folded over the upper edges 36, 38 of outer wall 18. 
     The folded over edges 46, 48 are pressed tightly over the upper edges 36, 38 so as to secure inner wall 16 to outer wall 18 with inner wall 16 being in upwardly spaced relation thereto at all points along it surface except for the upper edges 46, 48. As can be seen in FIG. 3, the upstanding walls 42, 44 of inner wall 16 are slanted so that they are spaced a greater distance from outer wall 18 at their lower ends. The greatest distance between inner wall 16 and outer wall 18 is adjacent the lower ends of side portions 42, 44 and adjacent the bottom wall 40. This insures that the greatest insulative effect will be provided adjacent the bottom wall 40 where the charcoal briquettes will be placed. The space between inner wall 16 and outer wall 18 is designated by the numeral 50 and this space or cavity 50 is filled with an insulation material so as to insulate the inner and outer walls 16, 18 from one another. The preferred material for use in cavity 50 is vermiculite, but other materials may be used. The insulative material should be non-combustible. 
     End walls 20, 22 are attached across the ends of outer wall 18, and are secured in position by means of rivets or screws 52, or other conventional securing means. End walls 20, 22 each include a plurality of vent openings 54 for permitting air and oxygen to enter the area immediately above bottom portion 40 of inner wall 16. The upper edges of end walls 20, 22 are bent over into a horizontal flange 56 (FIGS. 4-6). Resting on flanges 56 and spanning the distance between end walls 20, 22 is grate or grill 28. 
     Each end wall 20, 22 is provided with a pair of leg receiving openings 58 through which are inserted the legs 60, 62 of a U-shaped support 64 having a horizontal member 66 which interconnects legs 60, 62. Each leg 60, 62 includes at its upper end a bent foot 68 which limits the outward sliding movement of legs 60, 62 within leg receiving openings 58. The leg 60, 62 may be extended outwardly to their position shown in FIGS. 2 and 3, or they may be moved inwardly within openings 58 until the legs 60, 62 are substantially within the boxes 12, 14, with only the cross bar 66 being exposed to the outside of boxes 12, 14. 
     In order to hold legs 50, 62 in their operative position, a hook member 70 interconnects the two U-shaped legs 64 at the opposite ends of each box. 
     A pair of hinges 72 pivotally interconnect boxes 12, 14, and are attached to the upper edges of outer walls 18. The hinges 72 permit box 12 to be pivoted about a horizontal axis with respect to box 14 from the position shown in FIGS. 2 and 3, to the position shown in FIG. 1. As can be seen in FIG. 1, box halves 12 and 14 together form a rectangular box. In this position, the cross bars 70 may be be utilized as a handle for carrying the device. Alternatively, hooks 70 can be removed and the U-shaped support members 64 can be slid into the boxes 12 and 14, leaving only the cross bars 66 exposed outside the box halves 12, 14. A first latch member 72 is carried on box half 12 and a second latch member 74 is mounted on box half 14. As can be seen in FIG. 1, these latch members 72, 74 are positioned adjacent one another and may be latched together to hold the two box halves 12 and 14 in the position shown in FIG. 1 for transporting. In this position, the device can also be used for smoking or cooking various types of foods. 
     The outer surfaces of the box halves 12, 14 are insulated from the heat from the fire and coals within cylinder halves 12, 14. The insulative material within the space or cavity 50 helps provide this insulative effect. Consequently, the outer surface of outer wall 18 may be painted, either for decoration or for advertising on the outer surface of the device. The device is compact, and can be folded easily. It is sturdy, simple in construction, attractive in appearance, and efficient in operation. 
     Thus, it can be seen that the device accomplishes at least all of its stated objectives.