Abstract:
A rotating firebox cooking apparatus is disclosed. The rotating firebox may be constructed with a grilling apparatus, or it may be easily retrofitted to an existing conventional grilling apparatus. The firebox of the present invention is located within a chamber having a grill at or near the top of the chamber, and the firebox rotates the heat source within the chamber and underneath the grill, creating radiant and convection energy.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to outdoor cooking devices, and more particularly to outdoor cooking grills with a rotating fire element for the even cooking of grilled food using a transversally mounted standard rotisserie motor drive. The present invention allows for uniform cooking of grilled food without constant monitoring. 
     2. Discussion of the Related Art 
     Cooking by means of a grill has been and continues to be a popular method of preparing food, especially in summer months when the weather is conducive to outdoor activities. In the typical outdoor grill, the cook places food on a fixed grill surface, and provides a source of heat, which is typically fire. In the standard grill, whether it is charcoal fueled or gas fueled, the source of heat is fixed, that is, no provision is made for the movement of the heat source. This potentially causes uneven cooking of the food to be prepared, unless the cook is vigilant in monitoring the grill and moving the food around the grill frequently to provide uniform cooking of the food. This method of cooking requires both skill and attention and obligates the cook to remain with the food throughout the grilling process. 
     These problems are due to several factors. First, the fuel used may be a solid combustible material, such as wood chips or charcoal briquettes, a combustible gas, such as propane, electric, or a combination of the above. While grills employing solid fuel are generally less expensive than gas or electric grills, unique problems arise from their use. For instance, the solid fuel may not combust evenly, so that some areas of the grill receive relatively hot areas sometimes known as hot spots, while other areas are relatively cooler. 
     A second problem common to all known grills is the phenomenon of “flare up.” This occurs when fats and oils (which are, after all, largely composed of hydrocarbons) liquefy upon heating and are deposited on the heat source, where these fats and oils ignite. Upon ignition of these fats and oils, an area of increased combustion occurs, potentially charring the food disposed above on the grill. In the event of “flare up,” the cook must either partially extinguish the increased flames, or quickly move the food to a new area of the grill that is not currently flaring up. However, since more fats and oils usually drip into the new area, “flare up” will occur again, so that the cook must expend considerable energy in responding to the “flare up” to avoid burned food. 
     Several attempts to ameliorate these problems have been proposed. These solutions fall broadly into three groups: Providing a movable grill surface to automatically move the food around the fire source; providing a modified intake of air and fuel mixture for altering the rate at which the fuel burns; and providing a mechanism for raising and lowering the fuel source to compensate for varying rates of fuel consumption through its combustion. 
     Methods and apparatuses for turning the grill surface and thereby rotating the food in relation to the heat source are known, such as those described in U.S. Pat. No. 5,787,873 issued on Aug. 4, 1998 to Whitehouse; U.S. Pat. No. 3,033,190 issued on May 8, 1962 to Atkinson; U.S. Pat. No. 2,819,667 issued on Jan. 14, 1958 to Victor; and French Patent No. 2,444,438 issued on Dec. 21, 1978 to Tier. While these grills aid in the uniformity of cooking by compensating for hot spots, they do not address the problems of “flare up” or efficient fuel combustion. 
     Other methods utilize a modified fuel or fuel mixture to ameliorate the phenomenon of uneven combustion of solid fuel. For example, U.S. Pat. No. 5,752,497, issued on May 19, 1998 to Combs et al. discloses a cooking grill with an air intake, a flue gas outlet, and a dampening mechanism for modifying the air and fuel ratios to achieve a desired cooking temperature at the grill surface. Several patents, including U.S. Pat. No. 773,744 issued on Nov. 1, 1904 to Hough; U.S. Pat. No. 391,274 issued on Oct. 16, 1888 to Ridgway; and U.S. Pat. No. 351,896 issued on Nov. 2, 1886 to Bowman disclose a furnace with a rotatable grate upon which fuel is disposed. In these examples, the grate is rotated so that the fuel is brought into contact with a fixed portion of the furnace, either a wall or a separate set of projections to mechanically agitate the fuel, and dispose of ashes and spent cinders of coal known as “clinkers” by mechanically agitating these “clinkers” through the grate, and thereby increasing the proportion of unspent fuel available for combustion. In U.S. Pat. No. 3,959,620, issued on May 25, 1976 to Stephen, Jr., electric coils provide the source of heat to produce a more uniform heat source. Additionally, it is well known to use a fuel mixture of propane, natural gasses (predominantly alkanes or alkenes) and air as a combustible nature for providing a source of heat. These solutions do not effectively control “flare up,” nor do they adequately provide solutions to uneven heating. 
     Finally, other solutions provide for raising and lowering either the grill surface or the heat source to help compensate for “flare up” and uneven combustion. In these solutions, the cook modifies the vertical distance of the heat source in relation to the grill in response to variations in combustion, such that when the heat source is producing relatively more energy, the heat source is moved away relative to the grill, and when the heat source is producing relatively less energy, the heat source is moved in closer relation to the grill. Examples of these solutions include U.S. Pat. No. 5,758,635 issued on Jun. 2, 1998 to Peterson, and U.S. Pat. No. 5,099,821 issued on Mar. 31, 1992 to Ceravolo. 
     None of the above examples adequately and simultaneously solves the problems identified with uneven combustion, “flare up” and constant monitoring. Therefore, there is a need for a cooking apparatus that simultaneously solves all of the above problems, 
     BRIEF SUMMARY OF THE INVENTION 
     According to the present invention, there is disclosed a rotating firebox cooking apparatus. The rotating firebox may be constructed with a grilling apparatus, or it may be easily retrofitted to an existing conventional grilling apparatus. The firebox of the present invention is located within a chamber having a grill at or near the top of the chamber, and the firebox rotates the heat source within the chamber and underneath the grill, creating radiant and convection energy. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The objects of the invention are achieved as set forth in the illustrative embodiments shown in the drawings that form a part of the specification. 
     FIG. 1 is a side elevational view in cross section of a cooking apparatus of the present invention; 
     FIG. 2 is a top plan view of a cooking apparatus of the present invention; 
     FIG. 3 is a top plan view of a cooking apparatus of the present invention with the lid removed; 
     FIG. 4 is a bottom plan view of a cooking apparatus of the present invention; 
     FIG. 5 is a top plan view of a lid for a cooking apparatus of the present invention; 
     FIG. 6 is a side elevational view of a lid for a cooking apparatus of the present invention; 
     FIG. 7 is a top plan view of a rotating firebox assembly of the present invention; 
     FIG. 8 is a side elevational view of a rotating firebox assembly of the present invention; 
     FIG. 9 is a top plan view of a grill surface of a cooking apparatus of the present invention; 
     FIG. 10 is a top plan view of a bowl of a cooking apparatus of the present invention; and 
     FIG. 11 is a side elevational view in cross section of a bowl of a cooking apparatus of the present invention. 
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF INVENTION 
     Referring to the drawings, FIG. 1 shows a rotating firebox grill of the preset invention generally at  1 . Referring to FIGS. 1,  3 ,  10 , and  11 , the rotating firebox grill  1  comprises a chamber portion  3  having a chamber bottom  4  and chamber walls  6 . In the preferred embodiment of the present invention, a plurality of legs  5  are disposed under the chamber  3  and are operatively engaged to the chamber  3 . The legs  5  act to stabilize the chamber  3  and provide space between the chamber  3  and the ground or other surface upon which the rotating firebox grill is placed for use. In the preferred embodiment of the present invention, one or more ventilation spaces  8  are provided in the bottom portion  4  of the chamber  3 , to allow air flow within the chamber  3 . The chamber  3  is preferably fabricated from a heat resistant material, such as a metal or metal alloy. More preferably, the chamber  3  is made of ceramic-coated steel. Preferably, chamber  3  includes handles  6 A attached to the walls  6 , to aid in transportation of the rotating firebox grill. 
     Referring now to FIGS. 1 and 9, near or at the top of chamber  3  is a grill surface  7 . The grill surface  7  is suspended over the bottom portion  4  of the chamber  3  using tabs or an integrally formed shoulder near of at the top of the chamber walls  6 , or in any other conventional way. As can best be seen in FIG. 9, the grill surface  7  is a conventional grill. 
     Referring now to FIGS. 1,  2 ,  5 , and  6 , in the preferred embodiment of the present invention, a lid  9  is adapted to fit over the walls  6  of the chamber  3 . The lid  9  is conventional, and preferably has an integrally formed interior rim  10  disposed on its underside, for communication with the chamber walls  6  of the chamber  3 . The lid  7  also includes a lid handle  11 , for installation of the lid  7  to the chamber  3  and removal of the lid  7  from the chamber  3 . In the preferred embodiment of the present invention, the lid  7  further has an adjustable vent  12  near the top of the lid  7 . The adjustable vent  12  is conventional. 
     In a conventional solid fuel burning grill, the chamber forms at least a part of the firebox, and contains the solid fuel. The solid fuel in a conventional grill remains stationary, unless the cook manually stirs the coals with a stick or similar tool. 
     However, in the present invention, referring now to FIGS. 1,  3  and  4 , a rotary assembly  15  rotates a separate firebox  21 , which holds the solid file  26 . In the preferred embodiment of the present invention, the rotary assembly  15  comprises a motor  17 , a generally cylindrical shaft  19 , and a firebox  21 . A bracket  16  preferably holds the motor  17  in place, to prevent unwanted movement of the motor  17 . The motor  17  is preferably a standard electric rotisserie motor, and may be battery operated (direct current) or powered with alternating current. The shaft  19  has an upper end  19 A and a lower end  19 B. Upper end  19 A of shaft  19  is preferably threaded, and adapted to mate with an internally threaded nut  20 . The upper end  19 A of shaft  19  further has an annular ring  18  formed therein, which forms a shoulder. The lower end  19 B of shaft  19 , a flattened portion is adapted to mate with a female connection within the motor  17  (not shown). 
     Referring now to FIGS. 1,  3 ,  7 , and  8 , the firebox  21  is preferably generally rectangular in shape. The firebox  21  has a bottom surface  29  and sides  30 . Near the center of the bottom surface  29  of the firebox  21  an opening  22  is adapted to receive the upper end  19 A of shaft  19 , until the shoulder formed by annular ring  18  abuts the bottom surface  29  of firebox  21 . The nut  20  is secured to the threaded upper end  19 A of shaft  19 , forming a tight fit to the lower surface  29  of the firebox  21 . 
     Referring to FIGS. 1,  3 ,  7  and  8 , in the preferred embodiment of the present invention, a central cup  27  is formed in the firebox  21 . The central cup  27  may contain water  28 , for example, to provide greater humidity that is sometimes desirable when cooking various foods. The central cup  27  defines a left side  23  and a right side  25  in the firebox  21 . As can best be seen in FIG. 3, the solid fuel  26  resides in the left side  23  and the right side  25  of the firebox  21 . The solid fuel  26  may be charcoal, charcoal briquettes, wood, or other effective fuel. 
     Referring to FIGS. 7 and 8, in the preferred embodiment of the present invention, a plurality of ventilation spaces  32  are formed in the bottom surface  29  of firebox  21 . Likewise, a plurality of ventilation spaces  31  are formed in the sides  30  of the firebox  21 . The ventilation spaces  31  and  32  act to provide additional air to the solid fuel  26 . 
     Optionally, the rotation assembly  15  may be added to a conventional cooking grill. This may require creating or enlarging a hole located within the chamber of the conventional grill, to accommodate the shaft  19  of the rotation assembly  15 , As different sizes of chambers are currently manufactured in conventional cooking grills, it is contemplated that the size of the firebox  21  would be made in correspondingly different sizes as well. The rotation assembly in this embodiment is analogous to that described in the preferred embodiment. The rotary assembly  15  comprises a motor  17 , a generally cylindrical shaft  19 , and a firebox  21 . A bracket  16  preferably is provided, to hold the motor  17  in place, and to prevent unwanted movement of the motor  17 . The motor  16  is preferably a standard electric rotisserie motor, and may be battery operated (direct current) or powered with alternating current. The shaft  19  has an upper end  19 A and a lower end  19 B. Upper end  19 A of shaft  19  is preferably threaded, and adapted to mate with an internally threaded nut  20 . The upper end  19 A of shaft  19  further has an annular ring  18  formed therein, which forms a shoulder. The lower end  19 B of shaft  19 , a flattened portion is adapted to mate with a female connection within the motor  16  (not shown). 
     In operation, the cook will first add solid fuel  26  to the firebox  21 , as well as water  28  to the central cup  27 , if desired. The cook then ignites the solid fuel  26 . The motor  16  is engaged, causing the firebox  21  to spin about its axis, with the combusting fuel spinning with it. It is preferred that no part of the firebox  21  touches the chamber  3  of the cooking apparatus  1 . The grill  7  is affixed in place, and food is put on the grill  7 . It has been found that the rotating firebox cooking apparatus described herein produces an even heat source, and provides both radiant and convection heat for uniform cooking of food. Very little monitoring is required on the cook&#39;s part, as compared with other methods of grilling. 
     Numerous variations will occur to those skilled in the art in light of the foregoing disclosure. For example, the grill chamber, while shown as generally cylindrical, may be hemispherical, frustoconical, or any other advantageous shape. The firebox may be shaped other than the generally rectangular shape shown Other drive connections between the rotation apparatus and the firebox may be employed, such as gears or belts, for example. When using alternative drive connections, the firebox may be adapted to orbit the interior of the grill chamber rather than spinning about the axis of a shaft, and this orbit may be eccentric, if desired. While the firebox is described in the preferred embodiment as having ventilation holes, the ventilation spaces may be any other shape, and may be completely absent.