Abstract:
An improved stackable charcoal briquet has a convex bottom and a concave top and is packaged in a stacked compact boxed package. A charcoal briquet having improved burning characteristics and also improved shipping and retailing characteristics is thereby provided.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of charcoal briquets for use in home barbequing and the like, and particularly to an improved shape for the briquet, package for the briquet, and method of burning the briquets in home barbequing. 
     BACKGROUND OF THE INVENTION 
     Charcoal briquets are widely used by consumers in cooking and barbequing in outdoor grills, grates, and other locations. Conventional charcoal briquets are pillow-shaped and sold in multi-pound paper bag containers. The briquets are contained somewhat loosely in the paper bag container. Because of the random loose pack, abrasion between adjacent briquets in the bag is common, creating dust which often leaks out of the bag. Thus, a dusty, messy environment is created in shipping and retailing these packages. Additionally, the bags themselves are not a convenient shape for stacking or palletizing. This makes the products difficult to handle in shipping and also in retailing. The bags often weigh 5, 8, 10, 15, and 20 pounds. Because of their shape and charcoal dusty condition, they are inconvenient for consumers to handle when shopping, transporting, or storing. 
     Charcoal briquets are mainly used to prepare barbequed or grilled food items. One mechanism of use is to pile charcoal briquets in the center of a grill, apply an ignition fluid to the piled briquets, and ignite the ignition fluid. An ignition fluid is required, as conventional charcoal briquets are slow to ignite. The burn time of the ignition fluid ignites the surface of the charcoal briquets in the pile. After a sufficient burn time, the charcoal briquets in the pile are ignited. This becomes apparent to the user when a gray ash layer forms on the surface of the briquets. When the ash layer is observed, the briquets are spread out in the grill bottom and are ready for use in cooking. 
     Charcoal briquets are conventionally fabricated from base fuels such as charred wood, coal, charred agricultural waste, and similar products. Conventional briquets also use a binder which can be a vegetable starch or other conventional binder material. Some conventional charcoal briquets also include ignition aids which are materials which ignite more quickly than the base fuel and help in ignition of the charcoal briquet. This invention is not concerned with the composition of the charcoal briquet, but rather the shape and packaging of the charcoal briquet that is useable with any charcoal briquet materials and composition. Conventional materials and compositions are well known in the art and described in, for instance, U.S. Pat. No. 5,762,656 to Burke, et al. 
     While charcoal briquets are widely used for cooking on grills and in barbeque pits, numerous problems exist with this fuel source. Conventional charcoal briquets are often hard to ignite and require the use of an auxiliary ignition fluid. Charcoal briquets are conventionally marketed in large bags which are difficult to handle in shipping, retailing and by the consumer. Such bags are not easily stacked, and cannot be conveniently displayed in an upright position in retail stores. Conventional charcoal briquets are normally packaged in large bags, from which a consumer must pour out the desired amount, measuring informally and often using less or more than is appropriate for the meal to be cooked. The remaining charcoal briquets in the bag must be stored in an open bag, which is messy, and often leaks carbon dust. The burn characteristics of conventional charcoal are also less than ideal with too much time being spent in the ignition phase prior to the cooking phase in which food is actually cooked over the ignited briquets. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, an improved charcoal briquet and package for multiple briquets is provided which overcomes the above referred to problems and others and is more conveniently marketed to consumers and used by consumers in grilling and barbequing. 
     In accordance with the present invention, a charcoal briquet is provided having a generally convex top surface, a generally concave bottom surface adapted to engage and rest upon a top surface of an adjacent briquet, and a generally rectangular periphery. 
     Still further in accordance with the invention, the briquet is provided with a central hole through from the bottom surface to the top surface. 
     Still further in accordance with the invention, a commercial package of briquets is provided in which a measured quantity of briquets is stacked one upon the other and contained in a cardboard box relatively tightly, confining the charcoal briquets in the stack and sealing the top and bottom of the stack. 
     Still further in accordance with the invention, the cardboard box containing the briquets is preferably coated or impregnated with wax or a similar substance, whereby the dust associated with the briquets is contained in the package, and the package acts as an integral ignition aid. 
     Still further in accordance with the invention, a one-stack package is sized to hold an appropriate number of charcoal briquets for a single barbeque or grilling event. 
     Still further in accordance with the invention, a commercial multi-pack product is comprised of several single stack packages fixed to or packed with one another into a multi-pack, multi-pound unit bearing a universal product code appropriate for the number of units being sold. 
     Still further in accordance with the invention, the charcoal briquets comprise four interconnected side walls of generally identical cross section forming a rectangle with each side wall having a volume surrounded by a generally flat, horizontal bottom surface; an upwardly and inwardly extending lower surface; and, an upwardly and inwardly extending upper surface generally parallel to the lower surface. The briquets also have a inner surface extending from the lower surface to the upper surface and surrounding a central hole. The bottom surface of the lowest briquet in the stack is adapted to rest upon a horizontal surface. The lower surface of briquets other than the bottom briquet is adapted to rest upon the upper surface of the next lower briquet around their entire periphery, thereby forming a generally stable and compact arrangement. 
     Still further in accordance with the invention, the lower surface of the briquet is gently curved in its convexity, but generally slopes upwardly and inwardly at an angle of about 30° to the horizontal. 
     Yet further in accordance with the invention, the upper surface of the briquet is somewhat curved in its convexity, but generally extends upwardly at an angle of about 30° or slightly greater than 30° to the horizontal. 
     Still further in accordance with the invention, the briquets are generally square in shape, having gently rounded outer peripheral edges interconnected by sharply rounded corners. 
     Still further in accordance with the present invention, the briquets are packaged in a tightly fitting cardboard box surrounding the periphery of the briquets, with the cardboard preferably coated or impregnated with wax or a similar substance. 
     Still further in accordance with the present invention, the briquets can be used to create grilling combustion by merely placing the single-stack container into a grill, igniting the outer package, allowing the ignition of the outer package to ignite the periphery of the briquets, and thereupon spreading the briquets into a charcoal bed. 
     It is a principal object of the present invention to provide a charcoal briquet product having increased surface area for improved burn characteristics and an improved compact package for this product. 
     It is still a further object of the present invention to provide an improved package for a charcoal briquet in which the charcoal briquets are tightly contained whereby abrasion between adjacent briquets is minimized, thereby reducing the creation of waste dust. 
     It is still a further object of the present invention to provide an improved package for charcoal briquets in which charcoal briquets are stacked in a compact form, minimizing the space occupied by the package during shipping, handling, retail display, transporting, and storage. 
     It is still another object of the present invention to provide a packaged charcoal briquet product in which generally rectangular charcoal briquets are stacked creating a rectangular solid box which is easily stacked, displayed, palletized, and merchandised. 
     It is still another object of the present invention to provide a packaged charcoal briquet product in a solid rectangular box which is less likely to leak charcoal dust than conventional bags. 
     It is still another object of the present invention to provide a rectangular charcoal briquet product which is easily handled by the consumer and used by the consumer in initiating a barbeque. 
     It is still another object of the present invention to provide a charcoal briquet product comprised of a number of single-use size charcoal briquet packages which can be easily separated and used by the consumer. 
     These and other objects of the present invention will become apparent from the following description of the preferred embodiment of the invention, taken together with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail and which is illustrated in the accompanying drawings which form a part hereof and wherein: 
     FIG. 1 is a top plan view of a charcoal briquet in accordance with the present invention; 
     FIG. 2 is a side view of the charcoal briquet of FIG. 1; 
     FIG. 3 is a bottom view of the charcoal briquet of FIGS. 1 and 2; 
     FIG. 4 is a cross-sectional view of the charcoal briquet of FIGS. 1 and 2 taken along line  4 — 4  of FIG. 1; 
     FIG. 5 is a perspective view of the charcoal briquet of FIGS. 1-4; 
     FIG. 6 is a top view of a stack of charcoal briquets within a cardboard retailing container with the top removed; 
     FIG. 7 is a side view of the stack of briquets in the box of FIG. 6 with the closest side wall removed; 
     FIG. 8 is a cross section of a stack of briquets in the box seen in FIG. 7 taken along line  8 — 8  of FIG. 6; 
     FIG. 9 is a top plan view similar to FIG. 6 showing a larger package of briquets using six adjacent vertical stacks; 
     FIG. 10 is a cross section of the package of briquets seen in FIG. 9 taken along line  10 — 10  in FIG. 9; 
     FIG. 11 is a cross section of the package of briquets seen in FIGS. 9 and 10 taken along line  11 — 11  in FIG. 10; 
     FIG. 12 is a top plan view of several individual use packages of briquets as seen in FIGS. 6-8 combined into a multiple unit product; 
     FIG. 13 is a side view of the multiple unit product of FIG. 12; and, FIG. 14 is a graph showing a comparison of combustion temperature versus time for the briquets of the present invention and conventional standard briquets. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same, FIG. 1 shows a charcoal briquet  10  in plan view. Charcoal briquet  10  has a generally square periphery with four sides  12 ,  14 ,  16 , and  18 . Each side has an outer peripheral edge  20  which is gently bowed outwardly towards its center, but relatively straight. The four edges  20  are interconnected by corners  22  with a radius of curvature significantly smaller than the radius of curvature of the gently bowed edges  20 . A hole  26  is located in the cental area of the briquet  10  between the sides  12 ,  14 ,  16 ,  18 . 
     Referring now to FIG. 4, one sees the charcoal briquet of FIG. 1 in cross section. The charcoal briquet  10  has an upper surface which is generally convex with a hole  26  in the center. The lower surface of the charcoal briquet  10  is generally concave. The briquet back side  12  is bounded by a generally planar horizontal bottom surface  30 , a rounded outer peripheral edge  32 , an upwardly and inwardly extending lower surface  34 , an upwardly and inwardly extending upper surface  36  and a vertically extending inner surface  38  extending between the lower surface  34  and upper surface  36 . The lower surface  34  is gently concave but overall extends inwardly and upwardly at an angle of about 30° from the horizontal. The upper surface  36  is gently convex and extends inwardly and upwardly at an angle of about or slightly greater than 30°. The lower surface and upper surface are generally parallel to one another. However, a slight divergence away from one another as one moves towards the center of the briquet may be used. 
     The front side of the briquet  16  is the mirror image of the back side of the briquet  12 . That is, the briquet  10  is symmetrical about its central axis as viewed in the cross section shown in FIG.  4 . Moreover, if one rotates the briquet by 90°, one still sees the cross section seen in FIG.  4 . That is, the briquet  10  is symmetrical with respect to the side walls  14  and  18 , as well as with respect to the side walls  12  and  16 , and all the side walls  12 ,  14 ,  16 ,  18  have identical cross sections at their centers and curve identically towards the corners  22 . 
     The central portion of the charcoal briquet  10  is occupied by a hole  26  bounded by the vertically extending inner surface  38  of each of the sides  12 ,  14 ,  16 ,  18 . As can be seen in FIGS. 1 and 3, the side walls are interconnected by curved hole corners  42 . Of course, the hole  26  could have a circular periphery rather than the rounded square periphery illustrated in the figures. Additionally, a briquet having a rectangular outline in the horizontal plane rather than a square outline accomplishes many of the objects of the present invention. 
     In the preferred embodiment, the briquet is approximately 2.39 inches wide when measured from the center of the outer periphery of one edge to the opposite edge. Thus, the width dimension from the center of the right side  14  to the center of the left side  18  is approximately 2.39 inches. Similarly, the dimension from the center of the front side  16  to the center of the back side  12  is approximately 2.39 inches. The overall height of the briquet from the bottom of the bottom surface  30  to the periphery of the hole  26  is approximately 0.8 inches. The thickness of the sides  12 ,  14 ,  16 ,  18  measured from the inner surface  34  to the outer surface  36  is approximately 0.42 inches. The width of the hole  26  measured diametrically at its narrowest portion is 0.42 inches. This gives an overall volume of the briquet of 2.16 cubic inches, with an approximate weight of 0.056 pound. The surface area of the briquet is about 13.7 square inches. This compares to a standard pillow shaped briquet as is commercially available having a volume of 2.12 cubic inches, an approximate weight of 0.055 pound, a surface area of 8.98 square inches. Thus, the briquet of the present invention having an approximately equal weight is provided with 150% of the surface area of the standard briquet. All of the above figures are approximate, as individual briquets vary considerably. 
     Referring now to FIGS. 6-8, one sees a stack of 19 identical briquets contained within a close fitting cardboard box. The box  50  has a back side  52 , a right side  54 , a front side  56 , and a left side  58 . The box is created from a single sheet of cardboard with an extension of the left side  58  being creased and then overlaying a portion of the front side  56  and adhered, as by gluing, to the front side  56 . Thus, a sealed square container containing a stack of briquets  10  is illustrated. The box  50  is approximately 2.53 inches wide (outside) in both the right to left and front to back dimensions. This provides inside dimensions snugly accommodating the stack of charcoal briquets  10 . Preferably, the box is made from cardboard coated with wax or a similar coating. 
     As can be seen in FIGS. 7 and 8, extensions are provided on the box side walls  52 ,  54 ,  56 ,  58  forming flaps which are folded and glued or otherwise interconnected forming a box bottom  62  and a box top  64 . The flaps connected to the box side walls are conventional and glued together or fastened together in conventional ways. 
     As can be seen in FIGS. 7 and 8, the bottommost charcoal briquet  10   a  rests upon the bottom  62  of the box  50 . The bottom surface  30  of the bottommost briquet  10   a  rests upon the cardboard bottom  62  around its entire periphery. A substantial bearing area is provided between the bottom  30  of the briquet  10   a  and the bottom of the box  62 . The second lowest briquet  10   b  rests upon the lower briquet  10   a  with the lower surface  34  of each of the sides  12 ,  14 ,  16 ,  18  of the second briquet  10   b  resting on the upper surface  36  of the sides  12 ,  14 ,  16 ,  18  of the bottom briquet  10   a . As can thus be seen in FIG. 8, the briquets engage one another over a substantial portion of the upper surface  36  of one briquet and lower surface  34  of the next higher briquet. 
     The briquets are substantially rectangular or square in outer peripheral shape. The downwardly facing lower surfaces  34  create a somewhat segmented downwardly facing concavity  70  having four separate continuous distinct surfaces on the four sides  12 ,  14 ,  16 ,  18 . In the preferred embodiment, the concavity is not a surface of rotation resembling a cone. However, such a shape could be used in implementing the invention. The downwardly facing concavity  70  mates with an upwardly facing convexity  72  formed by the upper surfaces  36  of the four sides  12 ,  14 ,  16 ,  18 . The mating of the concavity  70  and the convexity  72  as shown in the stack of FIG. 8 is self-centering. The most compact and stable disposition of the stack is with each of the briquets  10  centered and in full contact with the next lower briquet as illustrated in the figures. 
     The box  50  containing the single stack of charcoal briquets  10  is a stand alone retail package. Box  50  is printed with appropriate merchandising information, including a universal product code, and is shipped and sold as-is. The box  50  is rectilinear and therefore easily packed into cartons and palletized for handling and distribution. The box  50  is rectilinear and therefore easily stocked onto shelves, into end caps, or center-of-aisle displays at the retailer. The box  50  is sealed and therefore less likely to become contaminated with charcoal dust. The box  50  contains briquets  10  which are stacked in a stable, tight manner minimizing extra air space as well as friction and the creation of charcoal dust. The box  50  is easily purchased by the consumer, as its overall dimensions are approximately 2½×2½ inches by 10⅔. This box weighs approximately one pound and is very easily picked up, placed into a shopping cart, taken home for use, easily stored at home, and easily and cleanly transported in a consumer&#39;s vehicle for use at a park or picnic. 
     In use, the consumer can simply place the box as-is in a grill bed. The wax coated box  50  is ignited and as the box  50  burns, it in turn ignites the periphery  32  of the contained charcoal briquets  10 . As can be best seen in FIG. 8, the peripheral portions  32  are spaced from one another when compactly packed, with air gaps  76  provided between the briquet peripheries within the box to promote air flow as the box  50  burns, encouraging ignition of the briquet peripheral edges  32 . After the briquets are ignited, the stack is broken up by use of a poker or other appropriate implement. Thereupon, a jumbled random bed of briquets is provided which has a greater surface area per unit mass than conventional briquets. The greater surface area encourages quick combustion to the ready-to-cook state. Moreover, the holes  26  in the centers of the briquets  10  provide an air flow passage causing a vortex action of air passing through the briquets  10 , further encouraging combustion to the ready-to-cook temperature. 
     Referring now to FIGS. 9-11, a different method of packing the briquets  10  of the present invention is disclosed. FIGS. 9-11 illustrate a box of five pounds of identical briquets  10 . The five-pound box contains six stacks of briquets disposed in two rows of three. Each of the six stacks comprises an identical number (15) of briquets and the briquets are tightly contained in a rectangular box  80  having four sides  82 ,  84 ,  86 ,  88 . The box is constructed from a single sheet of wax-coated paper or cardboard with the sheet of cardboard having a tab extending slightly beyond the end of one of the sides  82  into an overlapping relationship with a second side  88  to which it is adhered. Flaps extend from the sides  82 ,  84 ,  86 ,  88  forming a box bottom  92  and a box top  94 . The flaps are engaged as is conventional, forming a completely closed container. This five-pound box  80  of briquets is much more compact, easily handled, and less subject to damage than equivalent bags of briquets. The five-pound boxes are rectilinear, easing stacking and palletization. This greatly eases shipping of the product and prevents damage to the product in shipment. The rectangular boxes are easily stacked onto shelves, displayed as aisle end caps or otherwise displayed at the retailer for purchase by consumers. Moreover, the packages are fabricated from linear cardboard stock, and are therefore easily printed with merchandising information prior to forming into the box. The sealed boxes are relatively easy for consumers to handle, use and store. Optionally, the box is provided with an attached handle by fixing a plastic (or similar material) strap to the top or two opposite sides. The briquets in the box  80  stack in a self-centering manner identical to that seen in the box  50  of FIG. 6. A stable, compact mass of charcoal briquets is thereby provided. 
     In use, the consumer can either use the entire five-pound box in a manner similar to the one-pound box described above, or open the top of the five-pound box and pour a desired amount of briquets into a pile at the center of a grill. The pile of briquets can then be ignited as conventional. Such a pile of briquets has more favorable ignition characteristics when compared to conventional briquets because of the large surface area-to-mass provided by the briquet shape, and because of the vortex air flow created by the holes  26  in the middles of the briquets in the stack. 
     FIG. 14 illustrates the progression from initial ignition (0 minutes) to the ready-to-cook condition of the charcoal briquets of the present invention, as compared to conventional standard charcoal briquets. Line  110  connects data points for the temperature of briquets in accordance with the invention. Line  112  connects data points for standard briquets. It can be seen that the charcoal briquets of the present invention reach a temperature in excess of 1000° approximately 15 minutes after initial ignition, whereas such a temperature is not reached for conventional briquets for approximately 25 minutes. Moreover, the briquets of the present invention hold their ready-to-cook temperature of about 1000° reasonably constantly thereafter. Temperature readings for tests conducted comparing the temperature at 5-minute intervals after initial ignition for the briquets of the present invention when compared to conventional briquets is set forth in Table 1 below. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 MINUTES 
                 INVENTION 
                 CONVENTIONAL 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 5 
                 478 
                 346 
               
               
                 10 
                 883 
                 327 
               
               
                 15 
                 1187 
                 433 
               
               
                 20 
                 1104 
                 591 
               
               
                 25 
                 997 
                 1067 
               
               
                 30 
                 929 
                 1032 
               
               
                   
               
             
          
         
       
     
     As can be seen with reference to the above table and the accompanying FIG. 14, obtaining appropriate cooking temperature is hastened, and maintenance of that temperature is greatly improved. 
     An alternative arrangement for packing multiple-pound units of briquets is shown in FIGS. 12 and 13. In FIG. 12, one sees a top view of eight boxes  50  identical in all respects to the package seen in FIGS. 6-8. The eight boxes  50  are held together by an outer wrapper  100  surrounding the sides  52 ,  54 ,  56 ,  58  of the closely-packed boxes  50 . The outer wrapper  100  lays closely against boxes  50 . The outer wrapper  100  is shown slightly spaced from the boxes  50  in the drawings for purposes of clarity only. The outer wrapper  100  is a wrap, such as a wide plastic wrap, which tightly binds the individual boxes  50  together into a single commercial product bearing its own universal product code  102  and marketing information. The outer wrapper  100  obscures the universal product code of the individual boxes  50  and allows the retailer to sell multiple units as a single package to consumers requiring or desiring more than a single pound of product. The consumer can easily handle the compact package, take it home, and remove separable one-pound boxes as desired. Moreover, the retailer can sell multi-unit packages in outer wrappers  100  or remove the outer wrapper  100  and sell individual one-pound packages  50  bearing their own marketing information. An outer box or similar container can be used in place of the wrapper  100 . 
     The invention has been described with respect to a preferred embodiment. Modifications and alterations of this preferred embodiment will occur to others upon the reading and understanding of the specification. It is our intention to include all such modifications and alterations insofar as they come within the scope of the inventive claims or the equivalents thereof.