Abstract:
An apparatus for simultaneously grilling food from above and below is provided having upper and lower grilling surfaces of gas fired tubes. The upper grill is hinged to lift up and provide access to the food and is vertically adjustable to accommodate variations in thickness of the item being cooked. The upper and lower grills are supported on a frame having a supply of combustion gases and induced draft exhaust system.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to cooking apparatus for grilling food and in particular to an apparatus with dual grills which simultaneously cook food from the top and bottom. Each of the grills comprise an array of gas fired tubes forming level cooking surface. 
     2. Prior Art 
     An example of a gas fired grill or broiler may be found in Potts, U.S. Pat. No. 1,294,159. The grill has a rack of tubes arranged to form a planar cooking surface. Combustion gases enter an intake manifold at one end of the tubes and exit an exhaust duct connected to the opposite end of the tubes. The tubes may be enclosed in an oven type chamber and a drip pan is placed below the tubes. Individual tubes may be removed from the rack for cleaning or replacement, but the entire rack of tubes is not easily removed. The food being cooked must be turned periodically to insure that it cooks evenly as heat is supplied only from below. 
     An example of a gas fired cooking apparatus which simultaneously cooks from above and below is disclosed in Dreyfus U.S. Pat. No. 2,723,617. The racks of tubes in Dreyfus&#39; apparatus are perforated burners which distribute a flame along their length. The pipes are not placed in contact with the food but rather the food is supported on cross bars above the pipes. One disadvantage of the aforementioned design is that the food to be cooked comes in contact with the combustion gases which may impart an undesirable flavor. 
     In Amici, U.S. Pat. No. 4,442,824 a gas fired apparatus is shown as an upper heat source for an outdoor grill. As in Dreyfus, a flame is distributed along a length of pipe. Small bricks suspended above the food absorb the heat and radiate it downward. Food is exposed to the combustion gases within the grill. 
     Individual electrical heating elements within a row of tubes are used in the following patents for cooking apparatus: 
     
         ______________________________________Nissen, et al.  U.S. Pat. No.                        3,320,873Burstein        U.S. Pat. No.                        3,448,678Bardeau, et al. U.S. Pat. No.                        3,472,156______________________________________ 
    
     The heated tubes in Nissen, et al. and Bardeau, et al. are in direct contact with the food as with the gas fired tubes used by Potts. Burstein discloses a radiant heat cooker with heated tubes both above and below a conveyor supporting the food. A shortcoming of electrically heated tubes is that they are slower to heat up and slower to respond to adjustments than gas fired cooking equipment 
     SUMMARY OF THE INVENTION 
     Therefore, an object of this invention is to provide a gas fired cooking apparatus that does not expose food to combustion gases. 
     Another object of this invention is to provide a cooking apparatus which grills food both from above and below. 
     Yet another object of this invention is to maximize heat transfer between the grill and the food being cooked, preferably by direct contact. 
     Still another object of this invention is to provide a cooking apparatus which is adjustable to accommodate a variety of sizes and shapes of food and is easily disassembled for cleaning. 
     Accordingly, a cooking apparatus is provided with an upper and lower grill, each made up of a set of hollow tubes. Combustion gases are introduced into the tubes of each grill through an intake manifold. An exhaust fan draws the hot combustion gases through the tubes and out an exhaust manifold. The upper grill is hinged at one edge allowing one to open the apparatus and place food on the lower grill. The upper grill is also vertically adjustable to be placed in contact with the top surface of food lying on the lower grill when the apparatus is closed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the front of the cooking apparatus. 
     FIG. 2 is an exploded view of the cooking apparatus. 
     FIG. 3 is a detailed view of the upper grill. 
     FIG. 4 is a detailed view of the burners for the upper and lower grills. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Without limiting the scope of the invention, a description of the preferred features of the invention is hereinafter set forth. 
     In general, the cooking apparatus has as an upper and lower gas fired grill supported by a frame. The upper grill may be raised so that steak, chicken and the like may be placed on the lower grill. The upper grill can then be lowered to rest on the food, which is cooked on two sides at once. Each of the grills are made up of a set of hollow tubes. Combustion gases are supplied at one end of the tubes and an exhaust system contains the gases exiting at the opposite end. Suitable gases for heating the tubes are methane, ethane, propane or butane. Other methods for producing hot gases to heat the tubes of the grills may be employed without deviating from the scope of the invention. 
     Referring to FIG. 1, cooking apparatus 1 has lower grill 2 made up of parallel tubes 3 arranged to form a planar cooking surface. Tubes 3 have an intake end 4 connected to intake manifold 5 shown in FIGS. 2 and 4. Combustion gases are delivered to intake manifold 5 where they are drawn through tubes 3. The combustion gases or exhaust gases exit tubes 3 at exhaust end 6. Exhaust manifold 7 directs the exhaust gases from exhaust end 6 back around the sides of lower grill 2. Exhaust manifold 7 has outlets 8 which engage slotted openings 9 in exhaust ducts 10. 
     Exhaust ducts 10 are part of frame 11 which support lower grill 2 horizontally. Frame 11 also has back plate 12 with slit 40 to receive intake manifold 5 of lower grill 2. As shown in FIG. 2, lower grill 2 may be disengaged from frame 11 for cleaning or repair. However, during operation, lower grill 2 and the portion of frame 11 to which it is connected, remain stationary. 
     Upper grill 13 has edge 14 pivotally connected to frame 11. Upper grill 13 has parallel tubes 15 which are arranged in a plane. Upper grill 13 is movable from a first position parallel to and overlying lower grill 2 to a retracted position as shown in FIG. 1, which would allow one access to the food on lower grill 2. Additionally, the portion of frame 11 connected to edge 14 of upper grill 13 is vertically extendable to accommodate various thickness of food between the two grills. 
     Each of tubes 15 of upper grill 13 have an intake end 16 and an exhaust end 17. Referring to FIG. 3, intake manifold 18 is connected to intake ends 16 of tubes 15. In a preferred embodiment, intake manifold 18 is made up of an elongated cylindrical chamber 19 having a side connected to intake ends 16 and a slotted inlet 20 opposite intake ends 16. Chamber 19 is in communication with intake duct 21 of frame 11. Intake duct 21 has a convex shaped opening 22 which conforms to the shape of chamber 19 shown in FIG. 2. Thus, when upper grill 13 is pivoted on edge 14, inlet 20 of chamber 19 continuously receives combustion gases from opening 22 in intake duct 21. Alternatively, chamber 19 could be concave and opening 22 could be convex. 
     Combustion gases entering tubes 15 of upper grill 11 exit as exhaust gases at exhaust ends 17. An exhaust manifold 23 is connected to exhaust ends 17 and directs the exhaust gases back around to edge 14. Exhaust manifold 23 has outlets 24 centered on edge 14 which are in communication with openings 25 in exhaust ducts 10. Since upper grill 13 may be vertically adjusted it is important that the flow of combustion gases to upper grill 13 and the flow of exhaust gases to exhaust ducts 10 remain uninterrupted. Referring to FIG. 2, intake duct 10 of frame 11 is vertically adjustable relative to back plate 12 supporting lower grill 2. Additionally, openings 25 in exhaust ducts 10 are covered with plates 26 having flanged holes 27. Plates 26 are connected to intake duct 21 and are slidable therewith. 
     Referring to FIG. 3, edge 14 of upper grill 13 is separated into chamber 19 and outlets 24 of exhaust manifold 23 by seals 28 shown in the cutaway view. Outlet 24 has neck 29 which is inserted into hole 27 of plate 26 during operation. Upper grill 13 can be disengaged from frame 11 by sliding edge 14 sideways until neck 29 is removed from hole 27 on first one side then the other. 
     Exhaust gases from both lower grill 2 and upper grill 13 are drawn into exhaust ducts 10. Main duct 30 connects exhaust ducts 10 along the bottom of back plate 12. Referring to FIG. 2, exhaust fan 31 is positioned in main duct 30 to induce a draft through the exhaust system and ultimately to draw combustion gases through tubes 3 and tubes 15 of lower grill 2 and upper grill 13, respectively. 
     As shown in FIG. 4, frame 11 has a separate means to deliver combustion gases to lower grill 2 and upper grill 13. Burner body 32 is connected to frame 11 opposite intake manifold 5 of lower grill 2. A gas line 33 is connected to burner body 32 which in turn distributes the gas along slot 34. Alternatively, burner body 32 may have a series of holes corresponding to tubes 3 of lower grill 2. 
     Combustion gas is supplied to intake manifold 18 of upper grill 13 by burner body 35 inserted in intake duct 21. Burner body 35 has slot 36 for distributing gas supplied from gas line 33. Valves 37 and 38 are supplied on gas line 33 to individually control the temperature of lower grill 2 and upper grill 13. Oxygen for combustion is drawn into intake manifolds 5 and 18 to mix with the gas by the pressure differential created by exhaust fan 31. 
     Referring back to FIG. 1, drip pan 39 is provided below lower grill 2 to collect juices from the food being cooked. Pan 39 may be removed from frame 11 for emptying and cleaning. 
     There are, of course, many alternate embodiments and modifications which are intended to be included within the following claims.