Patent Publication Number: US-10758084-B2

Title: Fuel efficient grill for direct and indirect cooking

Description:
This application is a continuation-in-part of U.S. Ser. No. 14/813,852, filed on Jul. 30, 2015, now allowed, which is a continuation-in-part of U.S. Ser. No. 14/575,227, filed on Dec. 18, 2014, and claims priority to such applications, which are incorporated by reference herein in their entirety. All of these disclosures are hereby expressly incorporated by reference as part of the present disclosure as if fully set forth herein. 
    
    
     FIELD OF THE INVENTION 
     The present inventions relate to grills. More particularly, the present inventions relate to fuel efficient grills that are capable of effective slow cooking and standard grilling, permit multiple locations for a fuel grate and provide efficient air flow and heat transfer. The present inventions further relate to vent assemblies and deflector or diffuser plates that provide for increased heat control, improved air flow and the easy addition of fuel. 
     BACKGROUND OF THE INVENTION 
     Kamado type grills have been in use for many years. Kamado typo grills have increased in popularity, particularly for those individuals that desire to slow cook or smoke foods using charcoal and the like as a fuel source. 
     Early examples of Kamado grills are shown and described in U.S. Pat. No. 3,276,440 and U.S. Design Patent No. D201,416.  FIGS. 1A, 1B and 2  of this patent show a representative prior art Kamado typo grill and a related slow cooking accessory. In general, such grills include a ceramic body  1  and a ceramic lid  2  which may be attached to the body with a hinge. The body  1  typically includes a side intake or draft door  3  to permit the intake of combustion air and the lid  2  includes a top vent  4  which permits hot air to exit. In this manner, air goes into the side draft door  3 , is heated by the coals and circulates to the top vent  4  for discharge. 
     The interior of typical Kamado grills includes a firebox  5 , also typically made of ceramic. The firebox  5  supports a fuel grate  6  spaced a short distance from the bottom of the body  1  and upon which charcoal or other fuel is placed. The firebox  5  fixes the location of the fuel grate  6  within the grill. The firebox  5  in turn supports an annular fire ring  7  which in turn supports the cooking grid  8  upon which the food to be cooked is placed. The fire ring  7  functions as a spacer to raise the cooking grid  8  above the fuel grate  6 . In this configuration, a grill of this type is most often used for standard grilling, i.e., direct heat under the cooking grid with no heat deflecting barrier between the fuel grate and cooking grid. 
     The above described Kamado type grills are also used, and in fact are popular for, indirect or convection slow cooking. When this mode of cooking is desired, Kamado type grills typically use a plate-shaped insert  9  with upstanding legs  10  that forms a heat barrier or deflector between the fuel grate  6  and cooking grid  8 , as shown generally in  FIG. 2 . See also, U.S. Publication No. 2014/0224750. Typically, the deflector plate  9  is also made of ceramic. In general the ceramic heat deflector  9  is placed on top of and is supported by the fire ring  7 , with legs  10  as part of or associated with the deflector  9  in an upstanding position. The cooking grid  8  is then placed on the legs  10 . In this manner, the heat from the coals is supposed to be deflected by the deflector plate  9  and rise around the exterior recessed edges of the deflector plate  9  to cook the food by convection. The ceramic components are thought to aid in the slow cooking and/or smoking process by retaining heat. In addition, the structure and material of the grill are thought to conserve fuel during the slow cooking process. 
     A commercially available Kamado type grill is known as the Big Green Egg® by The Big Green Egg, Inc. (biggreenegg.com). (This device is similar to that described above in  FIGS. 1A, 1B and 2 , and is further shown and described in U.S. Pat. No. 7,644,711. That patent discusses the general configuration of the Big Green Egg, but is more specifically directed to a spark arrestor and airflow control located on the side of the grill body near the bottom (see also related design Patent Nos. D615,814 and D615,807). The embodiment shown in the above referenced utility patent describes the direct cooking configuration. When indirect or slow cooking is desired, a ceramic deflector plate with upstanding legs is typically placed upon the fire ring with the legs pointed upward. The cooking grate is then placed on top of the legs. The deflector plate is used to facilitate indirect cooking by providing a heat deflecting barrier between the cooking grid and the fuel grate. The ceramic deflector plate, in conjunction with the ceramic body and domed lid, are intended to radiate heat while preventing flames and heat from cooking the food too quickly. It is also believed that less fuel is consumed. 
     Other similar Kamado type grills are also available, such as the Kamado Series by Vision Grills (see visiongrills.com). These grills are similar in structure and operation to the Big Green Egg and also use ceramic for the main structural components. These grills also have a firebox that supports the fuel grate at a fixed position near the bottom of the grill body and combustion air intake/draft doors on the bottom side of the grill body. The basic design, as well as a side intake and an ash catcher system, is shown and described in U.S. Publication No. 2011/0283990 A1. These grills also have an available ceramic deflector plate with upstanding legs that is placed and functions as discussed above. Kamado Joe, by Premier Specialty Brands, is another commercially available Kamado type grill, which is also similar in structure and function to the Big Green Egg (see kamadojoe.com). This device also has an available ceramic deflector plate with upstanding legs that may be used for indirect or convection slow cooking. Like the other devices discussed above, the Kamado Joe has a fuel grate which is supported in a fixed position near the bottom of the grill by a firebox. It also has a side air intake and ash drawer (see U.S. Pat. No. D683,177). As indicated, the lid and body of the foregoing Kamado type grills are constructed of ceramic. In addition, the available deflector plates for these grills are also typically made of ceramic. 
     Another commercially available, Kamado type grill, is known as the Broil King Keg by Onward Manufacturing Co., Ltd., which is generally shown and described in U.S. Publication No. 2009/0308373 A1. The major components and overall shape are largely similar to the ceramic Kamado type grills discussed above. For example, this grill has a draft door on the bottom side of the grill body and a fuel grate at a fixed position near the bottom of the grill body. However, unlike the above described ceramic grills, the body and lid of the Broil King Keg grill in constructed of double walled steel, with a plenum formed between the inner and outer steel shells. Although the identified published patent application describes that the plenum may be filled with air, in the preferred embodiment, as well as the commercial embodiment, the plenum between the double walls is filled with an insulating material, such as fiberglass. In addition, a deflector plate is available for the slow cooking mode, which is positioned between the fuel grate and cooking grid. The available deflector plate is described as preferably constructed from a solid piece of cast iron. 
     The commercially available Kamado type grills all suffer from several drawbacks. For example, the grills made from ceramic are exceedingly heavy and fragile. They are also expensive to ship and manufacture. In addition, ceramic does not release heat as well as other materials which impedes proper heating, convection and air flow and increases fuel consumption. Even the insulation filled, non-ceramic grill discussed above is heavy and cumbersome. And, the insulation is prone to becoming damp, which increases the weight and diminishes the insulating ability of the insulation. 
     In addition, all of the foregoing grills have fuel grates at a fixed position near the bottom of the grill. While such a position may be suitable for slow cooking by keeping the heat source further from the cooking surface, when these grills are used for direct cooking, the heat source is undesirably far from the cooking grid. This lack of flexibility requires the use of additional fuel, poor heating and can lead to uneven cooking. 
     Like the single position fuel grate, the side drafts or air intakes found on the known commercially available Kamado typo grills are also a disadvantage in certain grilling situations. For example, the bottom side vent location may be suitable (but not ideal) for slow or convection cooking. However, even with slow cooking, the side draft provides uneven air flow and creates unbalanced combustion, which begins behind the side draft door. This inhibits proper combustion and reduces convention. And, when used for direct cooking, the side drafts do not permit the fuel to get as hot as may be desirable. Thus, temperature is often difficult to control and heat dispersion suffers. 
     It has also been determined that the ceramic and cast iron deflector plates used with the Kamado type grills often result in overcooking the food. This is because they are place too close to the cooking grid and do not permit adequate air flow for convection or slow cooking. In addition, the materials used for the deflector plates, such as ceramic and cast iron, can overheat and become a cooking surface. This makes them too hot for desirable slow cooking. Moreover, known deflector plates can also make it difficult to add fuel, particularly when used for slow cooking or smoking, since cooking often takes place over many hours. 
     Because of the configuration of the used cooking grate, side draft air intake and the location and type of deflector plates used, the available Kamado type grills have less than optimal air flow and unbalanced combustion. As a result, more fuel is used, temperature control is difficult and cooking quality suffers. Moreover, the top vents of typical grills do not permit a high degree of adjustability. The present inventions overcome the above and other stated and inherent disadvantages. 
     Of course, standard charcoal grills are also well known and popular. Many of them are particularly useful for direct cooking. However, indirect cooking on many standard grills is often more difficult, especially for the novice user. As discussed below, others have tried to provide standard grills that efficiently slow cook, but the results have not been successful. 
     For example, there are charcoal grills available that use a double lined grill body (but a single layer lid) to purportedly improve air flow and more evenly cook food indirectly. Various examples of such grills are shown and described in U.S. Publication No. 2014/0165993 A1. In the embodiments discussed in this published applications (e.g.,  FIGS. 5A and 5B ), the draft or intake for the introduction of combustion air is a series of holes located on the upper side of the grill body. The body of such grills further includes an interior wall that is designed to purportedly direct the combustion air around the sides of the grill and to exit into the grill at various positions in relation to the fuel grate. Such grills are supposed to be advantageous for, among other things, use of the grill in windy conditions. However, the air flow is not ideal and the introduction of combustion air insufficient for properly heating the fuel. In addition, the fuel grate in such grills is in a lived position that is not ideal for both direct and indirect cooking. 
     Finally, Danish Patent No. DK 176696 B1 (see also related published Application No. DK 200101276A) shows an insert for a grill. This insert is shaped like a bowl, having an enclosed bottom and upstanding sides (see also FIG. 3 of U.S. Publication No. 2014/0165993 A1). This technology is believed to be incorporated into a grill liner sold under the Dancook name by Saber Grills, LLC (see e.g., dancookusa.com/main/patentedtechnology.aspx). In this device, the fuel grate is supported by the liner near the bottom of the liner, which is designed to heat the air in the grill and to catch grease and ash. Combustion air is introduced through draft holes on the bottom of the grill body. However, the combustion air is then directed up from the draft holes between the insert and the grill body. Combustion air is ultimately introduced position above the fuel grate. This device also has a fixed position fuel grate and a single layer lid, although some standard gas grills are believed to incorporate a double layer lid. Among other things, the device leads to poor air flow and heat dispersion. In addition, the liner must be removed to clean out the ash. The present inventions overcome these and other disadvantages as well. 
     Thus, there is a need for a fuel efficient grill that is capable of effective direct and indirect cooking that overcomes the stated and unstated shortcomings of known grills. In addition, there is a need for improved air flow and air flow control, as well as the need for ease in the addition of fuel. 
     SUMMARY OF THE INVENTION 
     The present inventions preserve the advantages of known Kamado type grills, and particularly grills for slow cooking, smoking and roasting, and overcome many of the disadvantages associated with those grills. In addition to effective indirect cooking, the present inventions preserve the advantages of standard grills, particularly for direct cooking. In general, the present inventions provide the flexibility to conduct both direct and indirect cooking using the same grill in different configurations. The present inventions also provide improved air flow and convection as well as improved temperature control and heat dispersion. The present inventions further provide for the ability to easily add fuel, both before and during cooking. The features and advantages of the present inventions are a result of the unique components and their combination. 
     In accordance with a preferred embodiment of the present inventions, a grill having a lid, the lid having an inner wall and an outer wall and forming a substantially hollow plenum between the inner wall and outer wall is provided. Also provided is a grill body having a top, a bottom and a plurality of air intake slots on the bottom, the air intake slots having a key shape. Included is an insert secured within the grill body, the insert having a top portion, a bottom portion and an intermediate portion, the top portion adapted to engage the top of the grill body, the intermediate portion adapted to support an annular retaining member and the bottom portion adapted to support a fuel grate. In the preferred embodiment, a hinged deflector or diffuser plate may be supported by the annular retaining member. The annular retaining member may alternatively support a fuel grate depending upon the type of cooking desired. A preferred hinged deflector or diffuser plate includes a middle section and two end sections wherein each end section is connected by a hinge assembly to the middle section such that one or both end sections may be rotated upwardly and wherein each section includes a substantially hollow plenum. Also in a preferred embodiment, the hinged deflector plate may include two sections, wherein each section is connected to each other by a hinge assembly such that either section may be rotated upward and wherein each section includes a substantially hollow plenum. An adjustable vent assembly may also be provided. 
     In accordance with another preferred embodiment of the present inventions, a grill having a lid, the lid having an inner wall and an outer wall and a hollow plenum formed between the inner wall and the outer wall and including a vent hole through the inner and outer walls is provided. The grill further includes an exterior grill body having a bottom and a plurality of elongated key shaped air intake slots radiating from the center of the bottom of the body; an interior grill body member within the exterior grill body, the interior body member having an open top portion, an intermediate portion adapted to support an annular retaining member and an open bottom portion adapted to support a fuel grate, the open bottom portion in fluid communication with the plurality of air intake slots and wherein a hollow space is created between the sides of the interior grill body member and the exterior grill body member; and, an adjustable vent assembly. In a preferred embodiment, the adjustable vent assembly includes a vent collar positioned in the vent opening of the lid; a lower vent plate having a plurality of vent holes, the lower vent plate pivotably mounted to the vent collar; and, an upper vent plate having a plurality of vent holes, the upper vent plate rotatably mounted to the lower vent plate. The hinged deflector or diffuser plate may include at least two sections, wherein each section is connected to the other by a hinge assembly such that either of the sections may be rotated upward and wherein each section includes a substantially hollow plenum. 
     In accordance with yet another preferred embodiment, a grill having a lid, the lid having an inner wall and an outer wall and forming a substantially hollow effluent plenum between the inner wall and the outer wall and an adjustable vent assembly on the lid are provided. Included are an exterior grill body having a bottom and a plurality of air intake slots in the bottom of the exterior grill body, the slots having a key shape; and, an interior grill body member positioned within said exterior body, the interior grill body member having an open top, an intermediate portion adapted to support an annular retaining member and an open bottom portion adapted to support a fuel grate. A hinged deflector plate to be supported by the annular retaining member, the deflector plate including a substantially hollow plenum may also be provided. 
     In accordance with another preferred embodiment of the present inventions, a grill having a lid, the lid having an inner wall and an outer wall and forming a substantially hollow plenum between the inner wall and outer wall is provided. Also provided is a grill body having a top, a bottom and a plurality of air intake slots on the bottom, the air intake slots having a key or P shape, with three such slots being most advantageous. Included is an insert to be secured within the grill body, the insert having a top portion, a bottom portion and an intermediate portion, the top portion adapted to engage the top of the grill body, the intermediate portion adapted to support an annular retaining member and the bottom portion adapted to support a fuel grate. In its preferred form, the insert has the shape of an inverted and truncated cone with an open bottom and creates at least a partial double walled construction of the grill body when secured within the grill body. When indirect cooking is desired, the present inventions provide a deflector or diffuser plate that is supported by the annular retaining member. In its preferred form, the defector plate has a first layer and a second layer, such that a hollow plenum is created between the first and second layers. When direct cooking is desired, the deflector plate is not used and optimally, the fuel grate is moved to and supported by the annular retaining member. A damper assembly may also be provided that selectively restricts the size of the opening of the key shaped slots to control the amount of combustion air and to allow ash removal. 
     The present inventions also provide a grill having a lid, the lid having an inner wall and an outer wall and a hollow plenum formed between the inner wall and the outer wall. A grill body is also provided which includes an exterior grill body having a bottom and a plurality of elongated, preferably key shaped air intake slots radiating from the center of the bottom of the body; and an interior grill body member within the exterior grill body, the interior body member having an open top portion, an intermediate portion adapted to support an annular retaining member and an open bottom portion adapted to support a fuel grate, the open bottom portion being in fluid communication with the plurality of air intake slots and wherein a hollow space is created between the sides of the interior grill body member and the exterior grill body member. When optimal direct cooking is desired, the annular retaining member supports a fuel grate so that the fuel is supported closer to the cooking grid. When optimal indirect cooking is desired, the annular retaining member supports a deflector plate and fuel grate is secured on the bottom portion of the inner grill body portion. The optimal deflector plate is a double walled construction and a hollow plenum is formed between the double walls. The present inventions also provide that the outer diameter of the annular retaining member is greater than the outer diameter of the deflector plate such that convection air can pass upward between the deflector plate and the interior grill body member. In preferred embodiment, an approximate one-half inch space is provided. Also as preferred, the inner body member is in shape of an inverted, truncated cone. And the space between the interior body member and exterior body member acts to insulate the grill body. 
     The present inventions further provide a grill including a lid, the lid having an inner wall and an outer wall and forming a substantially hollow effluent plenum between the inner wall and the outer wall; an exterior grill body having a bottom and a plurality of air intake slots in the bottom of the exterior grill body, the slots having a key shape; an interior grill body member positioned within said exterior grill body, the interior grill body member having an open top, an intermediate portion adapted to support an annular retaining member and an open bottom portion adapted to support a fuel grate; and, a deflector plate capable of being supported by the annular retaining member, the deflector plate having a substantially hollow plenum. The annular retaining member is configured so it may alternatively support a fuel grate. In a preferred embodiment, the interior grill body member is shaped like an inverted, truncated cone. In addition, a plurality of support brackets which are attached to the inside of the interior grill body member, and are adapted to support the fuel grate and the annular retaining member is also preferred. 
     A deflector plate for use in a grill is also provided. A preferred deflector plate has a first layer and a second layer, the layers attached to one another. A substantially hollow plenum is created between two layers. It is preferred, but not required, that the deflector plate be made of porcelain covered steel or stainless steel and that it be supported in the grill by an annular retaining member. It is also preferably generally circular. In a preferred embodiment, the space between the two layers is approximately one half inch. In this manner, the deflector plate deflects the heat from the burning fuel but does not act as a heat source. 
     In another preferred embodiment of the deflector plate, a hinged deflector or diffuser plate is provided. The preferred hinge deflector plate includes a middle section, the middle section having a first layer and a second layer, the second layer attached to the first layer and a substantially hollow plenum formed between the first and second layers; two end sections, each end section having a first layer and a second layer, the second layer attached to the first layer and a substantially hollow plenum formed between the first and second layers; a first hinge assembly connecting one end section to the middle section; and, a second hinge assembly connecting the other end section to the middle section. 
     Another preferred hinged deflector plate is also provided, wherein two sections, each having a first layer, a second layer, a substantially hollow plenum between the first and second layers and a hinge assembly connecting one section to the other are provided. The hinged deflector plate may be supported in the grill by the annular retaining member. 
     The present inventions also provide for an adjustable vent assembly for controlling the venting of air through a grill, the grill having a lid with a vent opening. A preferred adjustable vent assembly includes a vent collar (or other means to help create the vent opening) positioned in the vent opening of the lid; a lower vent plate having a plurality of vent holes, the lower vent plate pivotably mounted to the vent collar; and, an upper vent plate having a plurality of vent holes, the upper vent plate rotatably mounted to the lower vent plate. In the preferred adjustable vent assembly, the lower vent plate may include an opposing pair of downwardly projecting pivot tabs, the vent collar may include an opposing pair of pivot brackets and a pivot pin is provided to pivotably mount the downwardly projecting tabs of the lower vent plate to the pair of pivot brackets of the vent collar. Four vent holes on the lower vent plate and four vent holes on the upper vent plate may also be provided. 
     Accordingly, it is an object of the present inventions to provide a grill that has the flexibility for efficient indirect and direct grilling. 
     It is another object of the present invention to provide a grill with drafts or combustion air intakes on the bottom of the grill and which are key shaped to provide suitable intake of combustion air for efficient slow cooking and standard grilling. They also provide for easy ash removal, better temperature control and better heat dispersion. 
     An additional object of the present inventions is to provide a fuel grate that may be moved to a plurality of vertical heights within the grill, such that the grill may be efficiently used for both direct and indirect cooking. 
     A further object of the present invention is to provide an air insulated, double walled air insulated deflector plate or an air insulated hinged deflector plate, either of which aids in indirect cooking and helps regulate temperature without allowing direct heat transfer or by absorbing and emitting heat to the same degree as ceramic and case iron plates and the like. 
     Still another object of the present invention is to provide a deflector plate or hinged deflector plate support structure or annular retaining member that selectively supports the deflector plate and/or fuel grate without removal of the annular retaining member and which permits adequate air flow for convection or indirect cooking and also permits effective direct cooking when a fuel grate is supported thereby. 
     Still yet a further object of the present inventions is to provide a hinged deflector or diffuser plate that permits, among other things, the easy addition of coal or other fuel and increased heat control (by, for example, permitting a portion or section of the deflector plate to be opened during cooking). 
     Still a further object of the present inventions is to provide an air insulated, double walled lid. 
     Still yet another object of the present inventions is to provide a liner or insert for the grill body that may support a deflector plate and/or a fuel grate and provides air insulation between the liner and the grill body for heat retention and fuel efficiency. 
     Still yet an additional object of some embodiments of the present inventions is to prevent air flow between the liner and the grill body and to direct hot air from the lower air intakes up through the open bottom of the liner and through the top of the grill. 
     Yet another object of the present invention is to provide a grill that has a grill body, at least a portion of which is of a double wall construction. 
     Yet a further object of the present inventions is to provide the slow cooking features of a Kamado type grill while keeping the direct cooking features of a standard charcoal grill. 
     Yet an additional object of the present invention is to provide a charcoal grill having improved air flow for more efficient cooking, is lightweight and has reduced fuel use. 
     A further additional object of the present invention is to provide an adjustable top vent or lid damper assembly, including rotatable and hinged members that provide a full range of adjustment of the vent opening from fully closed to fully open. 
     INVENTOR&#39;S DEFINITION OF THE TERMS 
     The following terms which may be used in the various claims and/or specification of this patent are intended to have their broadest meaning consistent with the requirements of law: 
     “Direct cooking” or “standard grilling” as used herein shall mean cooking food on a cooking grid that is located directly above the heat source without a heat deflecting barrier between the heat source and cooking grid. 
     “Indirect cooking” or “slow cooking” as used herein shall mean cooking with a heat deflecting barrier, such as a deflector plate, interposed between the heat source and the cooking grid such that hot air is directed around the deflector plate and/or circulated around the food. Indirect cooking is generally suitable for smoking or slow cooking or any situation where convection cooking is predominantly desired. 
     “Cooking grid” as used herein shall mean the surface upon which food is placed for cooking. The cooking grid, also referred to as “cooking surface” or “cooking grate,” may be made from a grid of stainless steel wire, cast iron and the like. 
     “Fuel grate” as used herein shall mean the structure used to support the coal, charcoal, wood or similar fuel for burning within the grill. 
     “Vent” or “top vent” as used herein shall mean the structure typically found on the lid of the grill, which is typically adjustable, that permits the selective release or venting of hot air from the grill. 
     “Draft” or “intake” openings as used herein shall mean the structure and/or opening on the grill body that permits the intake of combustion air to aid in the combustion of the fuel. 
     Where alternative meanings are possible, in either the specification or claims, the broadest meaning is intended consistent with the understanding of those of ordinary skill in the art. All words used in the claims are intended to be used in the normal, customary usage of grammar, the trade and the English language. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The stated and unstated objects, features and advantages of the present inventions (sometimes used in the singular, but not excluding the plural) will become apparent from the following descriptions and drawings, wherein like reference numerals represent like elements in the various views, and in which: 
         FIG. 1A  is a perspective view of a representative prior art Kamado type grill with portions cut away to reveal the interior components; 
         FIG. 1B  is an exploded perspective view of the prior art Kamado style grill of  FIG. 1A  showing the typical internal components; 
         FIG. 2  is a perspective view of a typical prior art deflector plate for use in slow cooking in the prior art grill of  FIG. 1A ; 
         FIG. 3A  is a cross-sectional perspective view of a preferred embodiment present invention, shown arranged for optimal indirect cooking; 
         FIG. 3B  is a detailed perspective view of an embodiment of the interconnection of the inner and outer walls of a preferred lid of the present invention and also showing details of the interconnection of the outer grill body and the inner grill body or insert of a preferred embodiment of the present invention, taken from insert  3 B of  FIG. 3A ; 
         FIG. 3C  is an exploded perspective view of a preferred embodiment of the present invention of  FIG. 3A ; 
         FIG. 3D  is a cross-sectional detail view of an edge of a preferred double walled deflector plate of the present invention taken along lines  3 D- 3 D of  FIG. 3C ; 
         FIG. 4  is a top plan view of one of the preferred draft or intake slots of the present invention shown with a representative blade of an optional damper for restricting the size of the openings of the slots and cleaning ash; 
         FIG. 5  is a top plan view of the preferred, key or P shaped air intake slots of the present invention on the bottom of the grill body, shown in their preferred arrangement; 
         FIG. 6  is a side cross-sectional view of a preferred embodiment of the present invention shown configured for optimal standard grilling with the fuel grate supported by a preferred embodiment of an annular retaining member; 
         FIG. 7  is a side cross-sectional view of a preferred embodiment of the present invention shown configured for optimal slow cooking with a preferred deflector plate supported by the annular retaining member and the fuel grate supported at the bottom of the interior grill body or insert; 
         FIG. 8A  is a top plan view of a preferred embodiment of the annular retaining member of the present invention; 
         FIG. 8B  is a side cross-sectional view of the annular retaining member of  FIG. 8A , taken along lines  8 B- 8 B; 
         FIG. 9  is an exploded perspective view of a preferred embodiment of an adjustable vent assembly of the present invention; 
         FIG. 10  is a perspective view of the preferred embodiment of the vent assembly of  FIG. 9 ; 
         FIG. 11  is a perspective view of the preferred vent assembly of  FIG. 10  shown in an open position and showing a potential alignment of the vent holes on the upper and lower vent plates; 
         FIG. 12  is a detailed view of one potential alignment of upper and lower vent holes on the upper and lower vent plates of the preferred adjustable vent assembly taken from inset  12  of  FIG. 11 ; 
         FIG. 13  is a perspective view of a preferred embodiment of a hinged deflector or diffuser plate of the present invention; 
         FIG. 14  is an exploded perspective view of the hinged deflector plate of  FIG. 13  showing two end sections, a middle section and preferred hinge assembly components connecting the end sections to the middle section; 
         FIG. 15  is an exploded perspective view of a preferred end section of a preferred deflector plate showing the first and second layers forming a substantially hollow plenum and the hinge member associated with that section; 
         FIG. 16  is a perspective view of an end section and associated hinge member and middle section and associated hinge member of a preferred hinged deflector plate shown prior to assembly of the hinge assembly, and is also representative of an embodiment of a hinged deflector plate having only two sections; and, 
         FIG. 17  is a perspective view of the end and middle sections of the hinged deflector plate of  FIG. 16  shown connected together with a preferred hinge assembly. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Set forth below is a description of what is currently believed to be the preferred embodiments or best representative examples of the inventions claimed. Future and present alternatives and modifications to the embodiments and preferred embodiments are contemplated. Any alternatives or modifications which make insubstantial changes in function, purpose, structure or result are intended to be covered by the claims of this patent. Various preferred embodiments of preferred grill components are also shown and described herein. 
     Examples of the present inventions may be seen by reference to  FIGS. 3A-8B . A preferred embodiment of grill  20  is shown in  FIG. 3A . Although preferred, but not a limitation, the overall shape is similar to, but slightly more elongated than, the typical Weber® kettle. The silhouette of the Weber kettle grill is a registered trademark of Weber-Stephen Products LLC. In addition, the preferred material for construction of the lid  22  and grill body  24  is porcelain coated steel or stainless steel. The grill  20  includes a lid  22  and a grill body  24 . Lid  22  may be attached to body  24  with optional hinges (not shown). It will be understood by those of skill in the art that hinges are not required and that if desired, there are a variety of well known hinges from which to choose. 
     Lid  22  includes a vent  26  that is preferably located in the top center. It has been determined that the location of the vent  26  and vent opening  28  at the top center of the grill lid  22  is best for indirect cooking and is also suitable for direct cooking, although other locations for vent  26  on the lid  22  may be used as will be understood by those of skill in the art. Vent  26  typically includes a cover  27  (see  FIGS. 6 and 7 ) which is rotatably adjustable and may contain a plurality of holes. The vent  26  opening may be increased or decreased by rotating the vent cover  27 . Examples of suitable vent covers  27  are well known to those of ordinary skill in the art. However, a unique and preferred vent cover  27 , referred to herein as adjustable vent assembly  80 , is shown in  FIGS. 9-12  and discussed in more detail below. This adjustable vent assembly may be used with the grills of the present inventions but may also be used independently with a wide variety of other charcoal and gas grills. 
     The bottom of grill body  24  includes a series of draft or air intake slots  28  that permit the introduction of combustion air into the grill  20 . Known grills have used a series, and preferably three, radially elongated slots as the draft for the grill. However, and as hereinafter described, it has been determined that, unique key or P shaped air intake slots or drafts  28  are preferred and enable efficient combustion, proper air flow and the preferred amount of adjustability for both direct and indirect cooking. 
     As partially shown in  FIGS. 3C and 4 , a damper  30  may also be provided. Damper  30  may be used to restrict the opening size of drafts  28  and may also be used to remove ash from the grill. Damper  30  may consist of a number of inverted V-shaped blades  31  attached to a center post (not shown) though a central hole  33  in the bottom of the grill body  24 . Preferably, damper  30  is a shutter type damper wherein the blades  31  extend from and are rotatably secured to the center post. A handle (not shown) that protrudes through the grill body  24  may be provided to enable the user to rotate the blades to remove ash or to adjust the size of draft slots  28  to adjust the amount of combustion air. A preferred example of a damper  30  that may be utilized with the present inventions is shown and described in U.S. Pat. No. 4,416,248 to Weber-Stephen Products LLC, which is incorporated herein by reference. 
     Grill  20  also includes a fuel grate  32  upon which charcoal, coal, wood or another fuel to be burned may be placed. A cooking grid  34 , which may include an optional handle  35 , is also provided. Cooking grid  34  supports the food to be cooked. A plurality of legs (not shown) may also be provided on grill body  24 , although other types of stands, carts and/or tables may be suitable in certain circumstances and as understood by one of skill in the art. In a preferred embodiment, an annular retaining member  36  is provided which is capable of supporting a deflector or diffuser plate  38 , hinged deflector or diffuser plate  38   1  or a fuel grate  32 , depending upon the type of cooking desired, as hereinafter described. 
     It will be understood by those of ordinary skill in the art that a variety of features may be added to grill  20  compatible with the present inventions. For example, various ash catchers (not shown) may be incorporated. Examples of suitable ash catchers are shown and described in U.S. Pat. Nos. 4,576,140; 4,498,452; 5,036,832; 6,155,248; and 6,318,356, all of which are assigned to Weber-Stephen Products LLC and are incorporated herein by reference. Similarly, a variety of fuel igniters (not shown) may be provided for use with the present inventions. Examples of suitable igniters that may be applied to the present inventions include those shown and described in U.S. Pat. Nos. 5,213,075; 4,941,817; and/or 4,302,181. All of these patents are also assigned to Weber-Stephen Products LLC and are incorporated herein by reference. 
     A preferred embodiment of double walled grill lid  22  may be seen by reference to  FIGS. 3A, 3B and 3C . Lid  22  includes an inner wall  41  and an outer wall  40 . The inner wall  41  and outer wall  40  are assembled or manufactured to create a substantially hollow plenum  42  between the inner  41  and outer  40  walls. Lid  22  also includes a vent opening  48  which is defined by collar  43 . Preferred lid  22  is generally hemispherical, although other shapes are acceptable. As discussed, suitable known vent covers  27  may be used as are well known to those of skill in the art. In addition, a preferred embodiment of an adjustable vent assembly  80 , an embodiment of which is shown in  FIGS. 9-12 , may be used with the grill  20  of the present inventions. The adjustable vent assembly  80  may also be used with standard gas or charcoal grills. 
     Outer wall  40  terminates in an outwardly facing flange  44  (sec  FIG. 3B ). Flange  44  is generally horizontal and extends around the circumference of the bottom of outer wall  40 . Similarly, inner wall  41  also terminates in an outwardly projecting, generally horizontal flange  45 . In a preferred embodiment, flanges  44  and  45  mate at their outer edges and are secured together with a circumferential clip  46 . Rivets or other means may be used to secure clip  46  and/or flanges  44  and  45 . In this manner, a substantially hollow, air filled plenum  42  is created between the inner  41  and outer  40  walls of lid  22 , which provides the desired insulation that is particularly useful for indirect cooking. 
     It will be understood by those of ordinary skill in the art that inner wall  41  and outer wall  40  may be secured together in a variety of ways consistent with the present inventions. For example, they may be welded together or constructed from a single sheet of material. Bolts or rivets (not shown) may be used in lieu of clip  46 . Alternatively, either of the flanges  44  and  45  may be folded over the other to create the connection between the outer  40  and inner  41  walls. In addition, beads, seals or gaskets of insulating material may also be used as will be understood by those of skill in the art. 
     It is not necessary for the present inventions that the plenum  42  be hermetically sealed. However, the preferred configuration described above seals the lid plenum  42  and helps prevent heat from escaping. It has been determined that the air in the plenum  42  acts as an insulator and helps lid  22  retain heat during cooking. In addition, the preferred lid  22  is lighter than those constructed of ceramic or those of metal filled with insulation such as fiberglass. 
     The preferred embodiment of grill body  24  is shown in  FIGS. 3A and 3B . Body  24  includes an exterior body member  50  and an interior body member or insert  51 . The top of outer body member  50  terminates in an outwardly projecting, circumferential, generally horizontal flange  52 . Exterior body member  50  is generally hemispherically shaped, although other shapes are acceptable. The bottom of outer member  50  includes a plurality of air intake slots  28  as hereinafter described. A center hole  33  may be provided in the bottom center of exterior body member  50  to accept a center post (not shown) that rotatably supports blades  31  of a typical damper assembly  30 . Legs (not shown) may be attached to exterior body member  50 . A handle (not shown) may also be provided. 
     In a preferred embodiment, inner body member  51  is generally in the form of an insert to exterior grill body  50 . Among other things, liner type inner body member  51  provides for ease of manufacture. However, it will be understood by those of ordinary skill in the art that there are a variety of ways inner body member  51  may be formed. For example, outer body  50  and inner body  51  members may be formed from a single piece of material. When assembled, a gap  47  is formed between inner body member  51  and outer body member  50  that acts as an insulator and aids in cooking and fuel efficiency. 
     In one preferred, liner type embodiment inner grill body member  51  is shaped like an inverted and truncated cone. Inner body member  51  has an open bottom with a bottom edge  53 . Bottom edge  53  abuts the inside wall of outer body member  50 . Although not required, it will be understood that bottom edge  53  may be secured to the inside of exterior body member  50  by a variety of well known means. In this preferred embodiment, the bottom edge  53  is sealed or otherwise closed when it meets the inside of exterior body member  50 . In this manner, heated air is prevented from flowing between inner body member  51  and outer body member  50  so that the heated air flows upward from fuel grate  32  without significant heat loss. In other preferred embodiments, the bottom edge  53  does not abut the inside wall of outer body member  50 . Thus, it is not secured to the inside wall of exterior body member  50 . It has been determined that whether the bottom edge  53  abuts the inside of exterior member or whether there is a gap between the members  53  and  50  is largely a matter of design choice and manufacturing expedience. 
     Inner body member  51  also serves to house and/or support other components of the present inventions. Interior body  51  includes a top portion  54  and an intermediate portion  55 . Top portion  54  terminates in an outwardly projecting flange  56 . Flange  56  of interior body member  51  mates with and overlaps the outwardly projecting flange  52  of exterior body member  50 . In the preferred embodiment, flange  56  is secured to flange  52  by annular clip  57  (see  FIG. 3B ). It will be understood by those of skill in the art that the top  54  of interior body member  51  may be secured to the top of exterior body member  50  in a variety of other ways, including welding or being formed from the same piece of material. Alternatively, exterior flange  52  or outward flange  56  may be folded over one or the other to fix their relative position. In addition, seals or gaskets may be provided to help seal gap  42  to provide for better insulation, which increases heat retention and fuel efficiency. 
     The top portion  54  of interior body member  51  is preferably provided with a generally horizontal ledge  58  formed thereon. Ledge  58  is sized to support cooking grid  34 . Although ledge  58  is preferred, other means of supporting grid  34  may be used. For example, brackets (not shown) may be attached to the upper portion  54  to support cooking grid  34 . In this manner, among others, the upper body portion  54  is adapted to support a cooking grid  34 . 
     The interior of interior body member  51  is further provided with a plurality of support brackets  60  which may be attached thereto by welding, fasteners or other well known means. As shown in  FIG. 3C , brackets  60  include a lower support tab  61 . The lower support tab  61  projects inwardly, is generally horizontal and substantially coincides with the inner bottom edge  53  of interior body member  51 . Lower support tabs  61  are sized and designed to support fuel grate  32 . In this manner, and others that will be appreciated by those of skill in the art, the bottom of interior body member  51  is adapted to support fuel grate  32 . It will be understood by those of skill in the art that lower support tabs  61  may be individual members and not part of a bracket  60 . It will also be understood that the inner bottom edge  53  of interior body member  51  may be provided or formed with an integral, inwardly facing flange (not shown) to support the fuel grate  32 . 
     In the preferred embodiment, the upper end of bracket  60  is also provided with a generally horizontal, inwardly projecting upper support tab  62  (see  FIGS. 6 and 7 ). The upper support tab  62  generally coincides with the intermediate portion  55  of interior body member  51 . Upper support tabs  62  are sized and designed to support annular retaining member  36 , which in turn supports either deflector plate  38  or fuel grate as hereinafter described. It will be understood that upper support tabs  62  may be individual members (not shown) which are attached to an intermediate portion of interior body member  51  and do not have to be part of preferred brackets  60 . In a preferred embodiment, there are three brackets  60  equally spaced around the circumference of the interior of interior body member  51 . Four brackets  60  (not shown) are also preferred. In this manner, among others that will be known to those of skill in the art, the intermediate portion  55  of inner body member  51  is adapted to support the annular retaining member which is capable of supporting a fuel grate  32  or a deflector plate  38  as desired, depending upon the type of cooking to be conducted. 
     Preferred draft or air intake slots  28  are best shown in  FIG. 5 . Intake slots  28  include a key shaped protrusion  29 . It has been determined that the key or P shaped slots  28  provide the best air flow, and the most control over the air flow, for direct and indirect cooking purposes. The amount of combustion air permitted may be adjusted by, for example, V-shaped blades  31  of damper  30  (see  FIGS. 3A, 3C and 4 ). It should be noted that because of key shaped protrusion  29 , there is an intake opening even if blades  31  are in the fully closed position as shown in  FIG. 4 . This is particularly desirable for optimal slow or indirect cooking. 
     A preferred deflector or diffuser plate  38  may be seen by reference to  FIGS. 3A, 3C and 3D . Deflector plate  38  is generally circular and includes a first layer  65 , a second layer  66  and a substantially hollow plenum  67  formed between the first  65  and second  66  layers. In a preferred embodiment, first layer  65  has a downwardly projecting member around its circumferential edge. Second layer  66  has a U-shaped channel  69  around its circumferential edge. Downwardly projecting member  68  is crimped with U-shaped channel  69 . It will be understood by those of skill in the art that first layer  65  and second layer  66  may be attached or secured to each other in a variety of well known ways and to create the plenum  67 . The outside edges of deflector plate  38  are supported by annular retaining member  36 . The plenum  67  in the deflector plate  38  prevents plate  38  from becoming too hot and acting as a cooking surface and heat deflector when used for indirect cooking. In the preferred embodiment, the plenum  67  formed between the first layer  65  and second layer  66  is approximately one half inch. 
     An alternative preferred embodiment of deflector or diffuser plate  38  is shown as  38   1  in  FIGS. 13-17 . In one embodiment, the hinged deflector plate  38   1  is divided into three segments: namely, middle section  38 A and two end sections  38 B and  38 C. The sections  38 A, B and C are attached using deflector hinge mechanism  110  as hereafter described. It will be understood by those of skill in the art that while a circular shape of deflector plates  38  and  38   1  are preferred, they may be other shapes to coincide with the interior shape of the grill and/or annular retaining member  36  if they are supported by such a member. Middle section  38 A includes a first layer  65 A that includes a perimeter lip portion  63 A. Middle section  38 A also includes a second layer  66 A having a perimeter lip portion  64 A designed to mate with and be attached to lip  63 A. It will be understood by those of skill in the art that first layer  65 A and second lever  66 A of middle section  38 A may be attached together at perimeter lip portion  63 A of first layer  65 A and perimeter lip portion  64 A of second layer  66 A by screws, rivets, welding or other means (not shown). When connected together, a substantially hollow plenum  67 A is formed between the first layer  65 A and second layer  66 A of middle section  38 A. 
     Similarly, end sections  38 B and  38 C have a first layer  65 B and  65 C, each having a lip portion  63 B and  63 C and a second layer  66 B and  66 C, each also having a lip portion  64 B and  64 C. First layers  65 B and  65 C are attached to second layers  66 B and  66 C at lip portions  63 B and  63 C and lip portions  64 B and  64 C forming a substantially hollow plenum  67 B and  67 C between each layer  65 B and  65 C and  66 B and  66 C. 
     As best shown in  FIGS. 14 and 15 , and because a preferred alternative hinged deflector plate  38   1  has been divided into three sections, when first layers  65 B and  65 C of end sections  38 B and  38 C are attached to second layers  66 B and  66 C as described, each end section  38 B and  38 C has an open end  101  (one open end  101  of section  38 B is shown in  FIG. 15 ). Similarly, when the first layer  65 A is attached to second layer  66 A of middle section  38 A, there are two open ends  102  and  103  associated with middle section  38 A. Open end  101  of end section  38 B is adjacent to one of the open ends  103  of middle section  38 A and the other open end  102  of middle section  38 A is adjacent to open end  101  of end section  38 C. In the preferred embodiment, a hinge assembly  110  is also provided to connect the end sections  38 B and  38 C to the middle section  38 A. In a preferred embodiment, portions of the hinge assembly  100  also close the open ends  101 ,  102  and  103  and help form the plenums  67 A,  67 B and  67 C in sections  38 A,  38 B and  38 C. As a result, each section forms a substantially hollow plenum  67 A,  67 B and  67 C when interconnected by hinge assembly  110 . 
     A preferred embodiment of hinge assembly  110  may best be seen by reference to  FIGS. 14, 16 and 17 . As preferred, there are two hinge assemblies  110  pivotably connecting the end sections  38 B and  38 C to middle section  38 A. If deflector plate  38   1  is only divided into two sections, only one hinge assembly  110  will be required. Each hinge assembly  110  is composed of two mating pairs of hinge members  112 . Each hinge member  112  includes a face plate  113 , a pair of upper mounting flanges  114 , a pair of lower mounting flanges  115 , a knuckle  116  and a guide  117 . In the preferred embodiment, the mating pairs of hinge members  112  are mirror images of each other. 
     One hinge member  112  is mounted to the open end  101  of end section  38 B. The upper mounting flanges  114  are secured to first layer  65 B and the lower mounting flanges  115  are secured to second layer  66 B using bolts, rivets or other well known means. Face plate  113  encloses open end  101  and forms plenum  67 B. The mating hinge member  112  is mounted to the adjacent open end of middle section  38 A by securing upper mounting flanges  114  to first layer  65 A and lower mounting flanges  115  to second layer  66 A. Face plate  113  encloses open ends  102  and  103 . 
     When the two adjacent mating hinge mechanisms  112  are placed together, knuckles  116  and guides  117  are in alignment such that a clevis pin  118  may be inserted into each knuckle  116 . In this manner, end section  38 B may pivot upward from middle section  38 A. A handle  119  may be secured to each side of middle section  38 A and finger opening  120  may be provided on each end section  38 B and/or  38 C. In this manner, handle  119  may be used to place or remove deflector plate  38   1  and finger opening  120  may be used to pivot one or both end sections  38 B and/or  38 C as desired. Alternatively, a handle  119  may be secured to end section  38 B and/or  38 C (not shown). Similarly, end section  38 C is pivotably connected to the other side of middle section  38 A using a pair of mating hinge mechanisms  112 . One face plate  113  encloses the other open end  102  of middle section  38 A and the face plate  113  of the mating hinge mechanism  112  enclosed open end  101  of end section  38 C. Three substantially hollow plenums  67 A,  67 B and  67 C are formed in each of the sections  38 A,  38 B and  3 BC. In this manner, either or both end sections  38 B and/or  38 C may be pivoted upward to permit additional heat to pass around hinged deflector plate  38   1 . Alternatively, one or both sections  38 B and/or  38 C may be pivoted upward when it is desired to add additional fuel to the fuel grate  32  below. In the preferred embodiment, this is aided by finger opening  120 . It will be understood by those of skill in the art that  FIG. 16  is representative of a deflector plate  38   1  having only two sections  38 A and  38 B. 
     As indicated, the preferred alternative hinged deflector or diffuser plate  38   1  provides several advantages. For example, if deflector plate  38   1  is in place prior to use of grill  20 , one or both end sections  38 B and/or  38 C may be pivoted upward so that fuel may be placed on fuel grate  32  without removing the deflector plate  38   1 . Similarly, if additional fuel needs to be added during cooking, one or both end sections  38 B and/or  38 C may be pivoted upward and additional fuel added. Moreover, one or both end sections  38 B and/or  38 C may be pivoted upward during cooking to further control the temperature of the grill  20  by permitting increased air flow around deflector plate  38   1 . 
     It will be understood by those of skill in the art that other hinge assemblies  110  or other methods of connection may be used and that more or less deflector plate  38   1  sections may be used. In addition, it will be understood that the open ends of the respective sections may be left open or may be constricted with a cover plate other than the face plate  113  of hinge member  113  as described herein. 
     A preferred embodiment of annular retaining member  36  may better be seen by reference to  FIGS. 8A and 8B . As shown, it is formed from a plurality of circular members  70 . The circular members  70  are attached to each other and stiffened by a plurality of cross members  71 . The outer circumference of annular retaining member  36  coincides with the inner circumference of the intermediate portion  55  of interior body portion  51 . In the preferred embodiment, annular retaining member  36  is supported by upper support tab  62 . The interior circumference of annular retaining member  36  is sufficient to support deflector plate  38  or fuel grate  32 , depending upon the type of cooking desired, as hereinafter described. It will be understood by those of skill in the art that annular retaining member  36  may take other forms. However, it is preferred that annular retaining member permit the passage of convection air between the deflector plate  38  and the interior surface of interior body member  51 . In the preferred embodiments, the gap between the edge of deflector plate  38  and interior body member  51  is approximately one inch. This permits optimal air flow and temperature regulation and is particularly desirable for indirect cooking. 
     The present inventions also provide for a widely adjustable, vent assembly  80  as shown in  FIGS. 9-12 . Although the preferred vent assembly  80  is described in relation to use on the grills  20  of the present invention, it will be understood that it may be used with other grills. The preferred hinged vent assembly includes a vent collar  43  or similar means that fits within vent opening  48  of lid  22  (see  FIGS. 3C, 6 and 7 ). Vent collar  43  is provided with an opposing pair of pivot brackets  81  having holes  86  to accommodate pivot pin  83 . A lower, generally circular vent plate  84  is also provided. Lower vent plate  84  includes a plurality of vent holes  85 . The preferred lower vent plate  84  has four vent holes  85 , but it will be understood that more or less vent holes  85  may also be used. A central hole  87  is also provided on lower plate  84  to function as hereinafter described. 
     Lower vent plate  84  is provided with downwardly extending, opposing pivot tabs  79  having holes  82  to accommodate pivot pin  83 . Pivot tabs  79  are sized and spaced to mate with pivot brackets  81  such that holes  82  and  86  align to accommodate pivot pin  81 . In this manner, lower plate  84  is pivotably mounted to vent collar  43  so that it may be rotated upward from vent collar  43  as shown, for example, in  FIG. 11 . 
     A generally circular upper plate  88  is also provided. Upper plate  88  includes a plurality of vent holes  89 , which in the preferred embodiment coincides in number, shape and placement to vent holes  85  of lower plate  84 . A central hole  90  is also provided. Upper plate  88  may also include an upstanding tab  91  upon which a handle  92  may be secured. 
     Upper plate  88  is rotatably secured to lower plate  84  by a rivet  93  through central holes  87  and  90 , although other means of rotatably mounting will be understood by those of skill in the art. As a result, the size of the vent opening may be adjusted as shown in  FIG. 12 . For example, when vent holes  89  of upper plate  88  are fully aligned with vent holes  85  of lower plate  84 , the maximum amount of air through the vent holes  85  and  89  is permitted. As upper plate  88  is rotated, the opening between the vent holes  85  and  89  is restricted. Upon further rotation, the opening between the vent holes  85  and  89  may be fully closed. To provide maximum ventilation, the upper  88  and lower  84  plates may be pivoted upward along pivot pin  83  so that the entire vent opening  48  of vent collar  43  is available for ventilation. Accordingly, ventilation may be adjusted from a fully closed to a fully open condition that provides maximum control over cooking temperature, particularly, but not limited to, when it is combined with bottom damper  30  of the present inventions. It will be understood by those of skill in the art that vent assembly  80  may be used with the grills  20  of the present inventions or any other grills having lids and vents. It will also be understood that there are a variety of ways to pivotably connect lower plate  84  or upper plate  88  to vent collar  43 . It will further be understood that vent holes  85  and  89  may take a variety of shapes and there may be more or less than four such holes  85  and  89 . 
     Having described the principal components of a preferred embodiment of the grill  20  of the present inventions, the preferred operation will be described. The preferred configuration for indirect cooking is shown in  FIG. 7 . In this mode, fuel grate  32  is supported by lower support tabs  61  toward the bottom of grill body  24  and within interior body member  51 . Annular retaining member  36  is supported by upper support tabs  62 . Annular retaining member  36  in turn supports deflector plate  38 . In this manner, a heat deflecting barrier is interposed between the heat source on the fuel grate  32  and the cooking grid  34 . The majority of the heat flows upward around the edge of deflector plate  38  and inner body member  51 . In this manner, convection cooking is enhanced. And, because of the air insulated lid  22  and partially doable layered body  24 , fuel is conserved. 
     During slow cooking, the dampers  30  are preferably set so that only the key shaped protrusions  29  (or portions thereof) of air intake slots  28  are open. Combustion air enters the bottom of grill body  24 , is heated by the fuel on fuel grate  32 , is deflected by deflector plate  38  and up through the gap between inner body member  51  and the edge of deflector plate  38 , and exits through the lid vent  26  in the top center of lid  22 . This creates uniform fuel combustion, which in turn creates uniform air flow. It also maximizes fuel efficiency and results in a higher percentage of fuel utilization. When preferred adjustable vent assembly  80  is used, maximum adjustability may be achieved. 
     When direct cooking is desired, the grill  20  is configured as best shown in  FIG. 6 . In this situation, no deflector plate  38  is used. Instead, fuel grate  32  is supported by annular retaining member  36 . Typically, dampers  30  would be set to expose more of air intake slots  28  and allow more combustion air into the grill body  24 , as desired for optimal direct cooking. In the preferred embodiment, it is not necessary to remove annular retaining member  36  when changing between direct and indirect cooking, since annular retaining member  36  supports both the fuel grate  32  and the deflector plate  38 . The heat source from fuel grate  32  is closer to cooking grid  34  and there is no heat deflecting barrier between the two. In this manner, among others that will be understood by those of skill in the art, the flexibility inherent in the present inventions permits optimal direct and indirect cooking. In addition, the preferred deflector plates  38  and  38   1  do not act as a major heat source that also optimizes slow cooking. And, the double walled lid  22  and partially double walled grill body  24  provide insulation and retain heat for optimal cooking and reduced fuel consumption. 
     The above description is not intended to limit the meaning of the words used in or the scope of the following claims that define the invention. Rather, it is contemplated that future modifications in structure, function or result will exist that are not substantial changes and that all such insubstantial changes in what is claimed are intended to be covered by the claims. Thus, while preferred embodiments of the present inventions have been illustrated and described, it will be understood that changes and modifications can be made without departing from the claimed invention. In addition, although the term “claimed invention” or “present invention” is sometimes used herein in the singular, it will be understood that there are a plurality of inventions as described and claimed. 
     Various features of the present inventions are set forth in the following claims.