Patent Publication Number: US-9404660-B1

Title: Chambered flame oven

Description:
RELATED APPLICATIONS 
     This application claims priority benefit of and is a Continuation of U.S. Ser. No. 11/747,732 now U.S. Pat. No. 8,464,701 filed on May 11, 2007. 
     U.S. Ser. No. 11/747,732 claims priority to 60/871,252, filed Dec. 21, 2006. Each is incorporated herein by reference. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     Conventional ovens have been utilized over a long period of time and generally run off gas or electric energy to provide heat to a central cooking chamber. Oftentimes, conventional type of cooking ovens for commercial or residential purposes have some form of access in a front portion of a central cooking chamber. One form of a cooking element is a gas heating element, for example, in the bottom portion of the chamber where natural gas, hydrogen, propane or other combustible material is ignited to provide heat to the cooking chamber in one form. Of course other types of ovens include electrical resistance members where a relatively high degree of amperage passes through the heating elements to keep the cooking chamber at a desired temperature. 
     Traditionally, a flame tends to offer the psychological impact of security, warmth and fundamental hope for survival. A flame has been historically shown to be an extremely important component in many early cultures and societies. Of course, in modern culture, flames are utilized in certain capacities, such as open fireplaces and other types of uses where the amount of heat from such fixtures may not be the underlying rationale for the open fireplace structure. Rather, the nostalgic effect, or simply the opportunity to view an flame, causes the desire for investment in such a type of fixtures. 
     Disclosed herein is an embodiment where a flame is provided in conjunction with the cooking chamber. Through experimentation, the flame does not produce a sufficient amount of heat to properly heat a cooking chamber for cooking food. Therefore, a secondary heating system is provided herein which provides heat to a chamber for cooking. The flame is in visual communication with the chamber, and further can be viewed through the front door in one form. As further described herein, in one form the cooking chamber can have two key systems, one within base plate and further one within the chamber itself to provide a balanced cooking effect. 
     SUMMARY OF THE DISCLOSURE 
     Disclosed herein is a flame oven having a housing that partially defines a cooking chamber. There is a first heating system comprising a base plate heater having a base plate configured to transmit heat therethrough to an upper cooking surface. In one form of heating there is a chambered heating element configured to supply heat to the cooking chamber. A door is provided having a transparent region or view port, the door having a closed and open orientation where in the open orientation, access is provided to the cooking chamber. 
     A flame chamber is in the oven and defined in part by a backplate and a transparent portion, the transparent portion being interposed between the flame chamber in the cooking chamber. The flame chamber has a flame manifold operationally configured to disperse a flame therefrom when in an operational mode. 
     A control system is provided with a first temperature sensor positioned to gauge the temperature of the base plate and a second temperature sensor positioned to read the temperature of the cooking chamber. The control system reads the temperature data from the first and second temperature sensors whereby the control circuit alters the heat emission of the base heating element and the chamber heating element to maintain a desired set temperature in the base plate and in the cooking chamber. 
     Also disclosed herein is a method for cooking food where first a cooking chamber is defined with an upper cooking surface of the base plate and a flame chamber assembly having a transparent member is interposed between a burner and the central portion of the cooking chamber. A first heating system is provided having a heater positioned below the upper cooking surface of the base plate and providing a chamber heating element positioned in the upper portion of the cooking chamber. 
     A food item is placed on the upper cooking surface of the base plate and provides heat transfer from the first heating system and the flame chamber assembly where the flame chamber is not in communication with the cooking chamber. A control system is also provided that is configured to control the amount of heat transfer to the chamber heating element and the base heating element, and providing a chamber temperature sensor and a base plate temperature sensor which provides a temperature reading to the control system. The control system adjusts the heat transfer to the chamber heating element and the base heating element based upon the temperature readings of the chamber temperature sensor and the base plate temperature sensor. 
     A more detailed implication of the oven is further described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an isometric view of one example of the flame chambered oven; 
         FIG. 2  shows a partial sectional view of the flame chambered oven showing the central cooking chamber and the chamber heater as well as the base plate heating assembly; 
         FIG. 3  shows a sectional view of the oven showing the cooking chamber as well as the flame chamber positioned in a transverse rearward orientation with respect to the cooking chamber; 
         FIG. 4  shows a side profile sectional view showing the power electronics as well as the central cooking chamber; 
         FIG. 5A  shows a top sectional view of the oven showing a top view of the flame chamber; 
         FIG. 5B  shows a figure similar to  FIG. 5 , except the base plate is removed showing the preferred form of a base heating element; 
         FIG. 6  shows an exploded view of the door; 
         FIG. 7  shows a partially assembled view of the door member; 
         FIG. 8  shows a front panel assembly showing the door member along with the door control mechanism; 
         FIG. 9  shows a general exploded view of the oven in one form; 
         FIG. 10  shows one form of the internal cooking chamber and the portion of the flame chamber in an exploded view; 
         FIG. 11  shows one form of the electronics; 
         FIG. 12  shows an isometric view of the door control mechanism; 
         FIG. 13  shows the control mechanism with the rotary member in a closed orientation; 
         FIG. 14  shows a door control mechanism in the top view where the rotary mechanism is in an open orientation; 
         FIG. 15  shows an exploded view of the door control mechanism; 
         FIG. 16  shows a concept of a discrete flame chamber shown in an isometric sectional view. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in  FIG. 1 , there is a flame oven  20  which is shown in one form as a tabletop design, but of course can take a variety of installation methods. Before beginning the detailed description of one embodiment of the flame oven, there will first be a description of an axis system  10  as shown  FIG. 1 . The axis  12  indicates a vertical direction and the axis  14  indicates a lateral direction, where for general purposes of the description, the arrow  14  will be referred to as the right, and the opposing direction will be herein referred to as the left. The axis substantially orthogonal to the vertical and lateral directions is defined as a transverse axis, and for purposes of general description, the arrow  16  points forward and the opposing direction will be referred to as rearward. The axis system  10  is intended for general description purposes and is not intended to limit the concept in scope, and is provided to aid in the general orientation of the components. Further, the axes indicate a general direction, and are not necessarily perfectly orthogonal to one another. 
     Referring still to  FIG. 1 , the outer structure of the flame oven  20  is generally shown.  FIG. 2  shows a partial sectional view where the general components of the oven can be more readily identified. The flame oven is comprised of a housing  22 , a door  24 , a first heating system  26 , and a flame chamber assembly  28 . As further shown in  FIG. 2 , the flame oven in a preferred form has an electronic section  30  and various components define a cooking chamber  32 . 
     Referring now to  FIG. 3 , there will first be a description of the housing  22  where the flame oven  20  can be seen in a sectional isometric view. In general, the housing comprises a base portion  34  and an upper portion  36 . The front regions of the upper portion  36  of the base portion  34  comprise the front panel  38 . As shown in  FIG. 3 , the base portion of the housing  22  defines a lower chamber  40 . The lower chamber  40  is, in part, insulated by the insulation layer lower plate  86  of the base heating assembly  39 . As described further herein, the lower chamber generally provides cooler air to be passed vertically through the door chamber  199  and up through the upper convection vent/flame exhaust  142 , where such current is drawn from the rising hot combusted gas of the flame chamber assembly described further herein. 
     The housing as shown in  FIG. 1  further comprises an outer casing  42  which in one form can be a stainless steel. Positioned at the lower portion of the base portion are a plurality of support legs  44  which can be utilized to support the unit in one form. Of course, the flame oven  20  could be mounted in a variety of ways. 
     Now referring to  FIG. 2 , the upper portion  36  of the housing  22  comprises, in one form, an inner shell which in part defines the upper ventilation chamber  50 . The inner shell further has the lower surface  52 , which in part defines the upper convection vent  142  described further herein. 
     The cooking chamber  32  as shown in  FIG. 3  is contained within the housing  22  and is operatively configured to cook food items therein. The cooking chamber is defined, at least in part, by the upper heat containment member  60  having the upper surface and the base plate  62 . As shown in  FIG. 2 , positioned at the right lateral region of the flame oven  20  is a lateral heat containment member  63  where a similar type member is positioned at the opposing lateral region of the flame oven  20 . The cooking chamber  32  has longitudinally rearward and forward portions  64  and  66  as shown in  FIG. 3 , as well as first and second lateral portions  68  and  70  such as that shown in  FIG. 2 . As shown in  FIG. 4 , the cooking chamber further comprises an upper region  72  and a lower region  74 . As best shown in  FIG. 3 , positioned in the longitudinally rearward portion  64  of the cooking chamber  62  is the flame chamber assembly  28  which is described in detail further herein, but comprises in part the transparent member  122  which at least partially isolates the flame within the flame chamber  120  from the cooking chamber. The transparent member  122  of the flame chamber could be double-sided glass or thermal insulated transparent member which does not provide heat to the cooking chamber. In another form a piece of glass which provides a greater amount of heat transfer from the flame chamber can be employed. 
     Heat is provided to the cooking chamber by the first heating system  26 , which comprises the chamber heating element  78  and the base heating element  80  as best shown in  FIG. 4 . The chamber heating element  78  is positioned in the upper region  72  of the cooking chamber  32 , and in one form is an electrical type conventional heater. Further, the base heating element  80  can be an electrical type heating member. In one form, the heating element  80  is interposed between the base plate  62  and the lower plate  86 . As shown in  FIG. 10 , an interior casing  90  is provided, which in part defines the cooking chamber. Further shown in this figure is a rear draft plate  92  having a surface  94 , which as shown in  FIG. 3 , helps to define the flame exhaust passage  142 . As further shown in  FIG. 10 , the front plate  100  in part defines the cooking chamber access area  102 , which is adjacent to the door  24 . Referring now to  FIG. 9 , a base frame  104  is provided which is configured to house the base heating element  80  and the lower plate  86  thereon. 
     In general, as shown in  FIG. 4  heat is transferred to the cooking chamber  32 , not only by the first heating system  26  which comprises the chamber heating element  78  and the base heating element  80 , but further heat is transferred from the flame chamber assembly  28  as well. 
     There will now be a description of the flame chamber assembly  28  with additional reference to  FIG. 10 , where a flame housing  110  is shown along with the flame trough  112 . In general, the flame housing in part comprises the flame chamber  120 . The flame chamber  120  as shown in  FIG. 3  is positioned behind the transparent member  122 . In one form, a backplate  124  is utilized, which as shown in  FIG. 5A , has vertical corrugations which are bent, for example, as shown at  126  and concave like vertical vents at  128 . The front surface  130  is a reflective surface to reflect the flame, which emits from the flame manifold  132 . The flame manifold  132  is adapted to be housed in the flame trough  112 , such as that shown in  FIG. 10 . An igniter  134  ignites combustion gas that is emitted from the upper foraminous surface of the burner element/flame manifold  132 . The various orifices of indicated at  136  can be sized to allow a plurality of different gases, such as natural gas, propane or even hydrogen or other combustible material to be passed therethrough. With regard to the burner element  132 , the plurality of hole perforations in one form have portions where the hole members are condensed, having a greater number, or the area would have a greater orifice size to create a spiking-like effect along the lateral direction of the burning element  132 . As shown in  FIG. 5A , the areas for example at  131  have a higher-concentration cluster of open orifices. 
     Referring now back to  FIG. 3 , it can be appreciated that an upper surface defining a vent  140  is provided, which is in communication with the flame exhaust  142 . The rear draft plate  92  provides the surface  94  as shown in  FIG. 10  to allow a venturi-like action as the rising combusted gas passes through the flame exhaust  142 , and gas is transmitted through the upper convection vent  150 . In general, the lower surface  52  of the inner shell as shown in  FIG. 2  and the upper surface  61  of the upper heat containment member  60 . 
     For further discussion of the upper convection vent  150 , there will now be a description of the door  24 , with initial reference back to  FIG. 1 . As shown in the isometric view in  FIG. 1 , the door is shown in a closed orientation. Referring now to  FIG. 6 , there is shown an exploded view of the door  24 , which in one form comprises an outer transparent member  172  and an inner transparent member  174 . The door front panel  176  has upper and lower regions configured to engage the upper bracket  178  and the lower bracket  180 . The rear bracket  182  is configured to hold the inner transparent member  174 , and in part utilizes a perimeter seal  186 . 
     Referring now back to the upper and lower brackets  178  and  180 , as shown in  FIG. 7 , the upper bracket has a surface  190  defining an opening for the upper vent opening  192 . In a similar fashion, the surface  194  defining the opening  196  for the lower vent opening is positioned in the lower portion of the door  24 . It should be further noted, with reference to  FIGS. 6-8 , that the door can be made with two pieces of glass with this cooling effect as illustrated in  FIG. 3  by the cooling vector through the upper convection vent  150 . It should be noted that many other types of prior art ovens have many pieces of glass to provide a thermal insulation from the outside portion of the oven. However, with the cooling effect, present analysis and experimentation indicates that two pieces of glass can be utilized (in one form) to have a sufficiently cool outer transparent member  172 . 
     The upper and lower vent openings  192  and  196  shown in  FIG. 2  allow access to the door chamber  199 , which is positioned between the transparent members  172  and  174 . Referring now to  FIG. 8 , it can be appreciated that the outer transparent member  172  and the inner transparent member  174  in part cooperate to make the transparent region  198 . As further shown in  FIG. 8 , a handle  200  can be provided to allow for easy opening of the door, which is pivotally connected at the hinge connection  202 . A mechanism  204  is attached to the door and in one form of the door control mechanism  300  as described herein with reference to  FIGS. 12-15  assists in the opening and closing the door and holding it in an open and closed orientation. The front panel  38  as shown in  FIG. 8  further comprises the first lateral panel location  210  and the second lateral panel location  212 . Further, to aid in the description, there is an upper panel section  214  and a lower panel section  216 . Positioned in the second lateral panel section  212  is the interface portion  220  which is described further herein when discussing the control system and power electronics. Still referring to  FIG. 8 , it should be noted that the front panel section as shown in this figure can have a variety of modular units for a variety of visual effects.  FIG. 8  shows one type of a front facade arrangement, but of course other variations can be utilized as well. Further it should be noted that the front door can be removed rather easily from the unit and further separated from the door control mechanism  300  as further described herein. 
     Now referring back to  FIG. 2 , with the description of the door  24  in place, there will now be a description of a cooling system utilized in one form of the disclosure. In general, the lower chamber  40  has cooler air positioned therein, and this region is in communication with various openings along the lower panel section  216  of the front panel  38 , and these openings are in communication with the lower vent openings  196 . Therefore, air from the lower chamber  40  can be directed through the door chamber  199  and out the upper vent openings  192  to the upper convection vent  150 . 
     Therefore, the force of the rising gas through the vent  140  (as shown in  FIG. 3 ) from the combusted gas within the flame chamber  120  tends to have a venturi-like draw of cool air through the upper convection vent  150  and hence through the door chamber  199 . This of course allows for cool air to pass through the door chamber to cool the front transparent panel  172 . 
     With regard of the rear draft plate  92 , as shown in  FIG. 4 , an upper lip  93  is provided which increases rigidity given the thermal expansion and causes a buckling effect by making a beam and a greater moment of inertia about its transverse axis. If the angle is too steep or too shallow (too vertical) then the venturi effect may not work effectively to draft the air through the upper convection vent  150  from the door chamber  199 . An angle of approximately 20° from vertical +/−15 degrees in the broader scope works effectively to provide a venture like effect. 
     It should be noted that the transparent panels  172  and  174  do not need to be completely transparent, and the entire panel does not need to be transparent as well. However, a desirable effect of the flame oven  20  is allowing visibility of the flame chamber  120  from the transverse front portion of the flame oven  20 . In another form, a flame chamber could, for example, be positioned on the door at the door chamber. 
       FIG. 5B  shows a similar view to  FIG. 5A , however the base plate  62  is not shown in this drawing and the base heating element  80  is shown along with the temperature sensor  232 , both of which are now described in detail. 
     As shown in  FIG. 5B , the base heating assembly  39  is shown in one form. In general, the base heating assembly comprises the base heating element  80  which in a preferred form is comprised of first and second base heating element members  234  and  236 . Each of these heating element members are controlled by the control system discussed further herein. In general, the first and second base heating element members  234  and  236  can have electric current independently directed to either or both members. Of course, one form of having a base heating element  80  is by providing electric resistance heating elements. 
     Of course, in other forms, the base heating assembly can be provided, including having a disparate network of wires molded directly within the base plate  62 , of  FIG. 5A  or it could include a induction heating-type system where an inductive magnetic current causes an electronic resistance throughout metallic particles positioned within the base plate  62  and which create heat. Further, a plurality of induction members can be employed to have certain portions heated to accommodate various types of food items taking up different amounts of space on the base plate. As described now herein, the temperature sensor  32  in one form has two temperature sensing locations  240  and  242 , as shown in  FIG. 5B , which can receive temperature inputs to the control system. The temperature sensor  232  is shown with the extended rod member having first and second temperature sensor/thermocouple elements positioned at the locations indicated at  240  and  242 . It can be appreciated that the temperature sensor locations  240  and  242  are positioned near the first and second base heating element members  234  and  236  respectively. 
     It should be further noted that instead of a an electrical heating element type of oven, the central chamber could be a microwave oven, an induction heating oven, a convection oven, or even a rotisserie type of oven with a flame chamber portion positioned therein. 
     With reference to  FIG. 5B , in one form as previously described, the temperature sensor in the base plate has two locations  240  and  242  to take the temperature in conjunction with the first and second base heating elements  234  and  236 . However, additional heating elements can be employed, and the control system can provide different heating temperatures for different zones. For example, looking at the top view of  FIGS. 5A and 5B , there could be for example four or more zones of four discrete heaters with four or more temperature sensors corresponding to each region to provide different base heat at different regions for certain applications. One advantage of having several different zones is that in a commercial setting, or a setting where there are different demands upon the oven, one portion of the base heater can be heated to a first temperature, and the other portions can have no heat directed thereto to save energy. Furthermore, different types of menu items that require different base heat temperatures. It should also be noted that in other forms, conventional racks can be positioned within the cooking chamber  32  to provide additional surface area for cooking items therein. Of course in the broader scope the base plate is not a heating element but more of a conventional type of heating system is employed. It should further be noted that the base heating element could be a gas (as opposed to electric) heating element where the chamber, in which the electric element  80  is contained, could be a type of lower combustion chamber to have gas combusted therein providing heat and venting out the rear portion in a similar manner as the flame chamber. 
     The electronic section  30 , which is referred to as the power electronics section  30  is shown in  FIG. 11 . In general, the power electronics include a power input section  240  and a control system  242 . The input from the cord  244  can be either 110, 208, or 220 voltage with a minor modification to the electronics. The control circuit itself in one form is contained within the display module which is shown in  FIG. 8  at  211 . In one form, a microprocessor controller, which is conventional in the art, is utilized to use the logic. 
     The cord member  244  in one example transfers electric current to the terminal block  254  where there is a connection and a power feed to the four relays  255  where there is a relay for heaters and one relay for the light. Further power is directed to the transformer  256 , and then to the transformer  260  to a 5/12-volt power supply in one form 
     In general, the function of this is to feed power to the relays of 24-volt coils which are desirable because they are easier to handle. A control system is of 5V DC to control various logics which is conventional in the art. Further shown is an ignition module  258  for ignition of the unit. 
     The control system of the flame oven  20  is configured to control the temperature within the cooking chamber  32 . In general, as shown in  FIG. 5B , the base plate temperature sensor  232  is provided to detect the temperature within the base plate  62 . Further, a chamber temperature sensor  230  as shown in  FIG. 4  detects the cooking temperature within the cooking chamber  32 . The control system is a portion of the power electronics  30  in one form, where the control system reads temperatures from the temperature sensors to make heat input adjustments. The heating system is independent from the lower portion on the upper chamber. The lower portion has a thermocouple where there is a set point which can be described by the chef or some kind of program. For example the set point is 500° all of the thermocouples attempt to get at 500° and control their respective heaters in that zone. Further, there is desired range for operating, for invoking turning or turning off the relays. For example, this range could be plus or minus 5° in one form. The deadband cannot be too tight of an interval so the relays turn on and off too quickly, or it cannot be too large where the thermal inertia of the unit is so much that the temperatures pick up and exceed this deadband. Therefore, it can be appreciated that the control systems for the lower base heater and the upper convection heater are independent from one another. 
     There will now be a description of one form of a door control mechanism  300  as shown in  FIGS. 12-15 . In general, the door control mechanism  300  comprises a rotary member  302  and a base unit  304  which in one form are attached to a base plate  301 . Of course the base plate can be any type of structure which is configured to hold the rotary member  302  and the base unit  304  at predefined locations with respect to one another. 
     The rotary member has a cam extension  308  which is configured to engage the cam engagement/extension portion of the spring member  330  described further herein. In one form, the rotary member has a surface  310  defining an arcuate path  312  where a pin which operates as a travel limiting future  314  is positioned to travel within the arcuate path  312 . Referring to  FIGS. 13 and 14 , the arcuate path  312  has an open stop surface  316  and a close stop surface  318 . The surfaces help to find the extreme range of travel of the rotary member  302 ; however, the stop surface  320  further provides such limitation of rotation. The stop surface  320  is configured to engage the door opened spring stop  322 . In one form, the door opened spring stop  322  is a cantilevered spring which as shown in  FIG. 14  is configured to engage the surface  320  in order to provide a dampening-like cushioning effect when the door member is swung open. Oftentimes the door has sufficient mass to carry a certain degree of momentum, which can be damaging to the hinges when the door rapidly de-accelerates. Therefore, having a de-acceleration component, such as the door opened spring stop, helps to prevent the door from slamming open. 
     Referring in  FIG. 14 , there is shown the base unit  304 , which in one form is attached to the base plate  301 . The spring member  330  comprises the cam engagement portion  332  which in one form is a reel-like member pivotally attached to the arm portion of the spring member  330 . In one form, the spring member  330  is a partial cantilevered spring where the cantilevered portion  334  is positioned at one region, and a secondary spring element  336  is positioned at an opposing region of the cantilevered portion of the spring member. In one form, the secondary spring element  336  is adjustable by way of a thread adjustment screw  338 . The threaded adjustment screw can adjust the pre-tension within the spring as well as bias the cam engagement portion  332  toward the rotary member  302 . Of course, the threaded adjustment screw  338  is one form of adjusting the secondary spring element  336 . 
     A door closed sensor  340  is provided which can be implemented in a variety of forms. In one form, the extension  342  is positioned toward the rotary member  302  and configured to engage the sensor engaging surface  350  which in one form is a pin-like member. 
     Referring now back to the rotary member  302 , it can be appreciated that the cam extension  308  is configured to engage the cam engagement portion  332  of the spring member  330 . In one form, the travel limiting feature  314  has a perimeter region  356  having a lower surface which is configured to engage the upper surface  313  of the rotary member  302 . The upper surface  313  comprises a detent  315  as shown in  FIG. 13 , wherein the lower surface of the perimeter region  356  is in less frictional engagement to the upper surface  313  when the rotary member is in the closed orientation. Referring now to  FIG. 15 , it can be appreciated that the travel limiting feature/pin  314  is shown in an exploded view where the surrounding perimeter region  356  in one form is a washer-like member. The pin  314  (in one form of a travel-limiting future) is attached to the base member  360 , and of course can be adjustable to provide a prescribed amount of frictional pre-tension between the lower surface  357  of the perimeter region  356 , and the upper surface  313  as shown in  FIG. 15 . Of course, this is one form of providing a dampening-like mechanism of the range of travel of the door control mechanism. Other forms of a dampening system can also be employed; for example, the frictional force could be placed on the under portion of the rotary member  302  or have a torsion-like dampening system. After the forward surface  321  has disengaged from the cam engagement member, there is no longer an opening or closing force. The frictional force of the surface of the rotary member provides a convenient form of positioning the oven at intermediate locations beyond the engagement of the cam extension  308  and the cam engagement portion  332 . In one form, having the door open at least 10° prior to having the cam engagement portion  332  engage the forward surface  321  is a desirable amount of rotation to noticeably indicate to a person watching the oven that the door is clearly open. 
     Referring to  FIG. 15 , the exploded view shows one form of carrying out the door control mechanism  300 . As shown in this photo, the sensor  340  can be attached by way of fasteners  361  to the plate  362  which in turn is fastened by way of fasteners  364  to the base region  366  of the spring member  330 . In one form, the fastener  364  further attaches the spring member  330  to the base plate  301 . The pivot pin  370  pivotally attaches the rotary member  302  to the base plate  301 . A spacer  372  can be provided to limit the amount of friction therebetween. 
     The cam engagement portion  332  in one form is a wheel-like member which is pivotally attached at the location  376  on the spring member  330 . A wheel-like member is preferred as it will roll around the cam extension  308 . The preferred form of connecting the door control mechanism  300  to the actual door is to utilize the first and second pin members  380  and  382  which are offset from the axis of rotation of the rotary member  302  to supply a torque to and from the door to the door control mechanism  300 . The attachment point  317  in one form is two pins but of course could be any attachment transferring torque to the door. 
     Therefore, it can be appreciated that the door control mechanism  300  will operate in a manner such that the cam extension  308  having the outer surface  319  will engage the wheel/cam engagement portion  332  of the spring member  330 , and because of the relatively low coefficient of friction therebetween (in one form via a bearing holding the wheel member  332 ) the door will either be biased to the closed position or clearly biased to an open orientation. As shown in  FIG. 14 , the surface  319  has a forward surface  321  and a rearward surface  323 . Each surface provides a normal force which places a torque upon the rotary member  302 . In other words, the door will not be partially closed, but will be open to, for example, at least 20°, which clearly indicates to the door closed sensor  340  whether or not the door is open or closed and further visually indicates to the cook or person responsible for the oven that the door is open. It can therefore be appreciated that the door is forcefully closed, and also forcefully opened after a predefined angle with respect to the oven, and this action occurs without having to have a latch magnet or other type of attachment feature at the portion of the door opposing the hinge region as shown in  FIG. 2 . 
     Now referring to  FIG. 16 , there is shown in a partial sectional view a flame chamber  400  as a standalone unit. In this form, the internal chamber  402  is defined in part by the rear reflection plate  404  and a front transparent member  406 . The flame is dispersed through the flame manifold  408 , and the flame ignition system  410  ignites the flame in a conventional manner. The upper exhaust port  412  exits the combusted gas. A variety of conventional controllers fuel providers/regulators, similar to that shown at  414 , can be provided. In one form, propane is provided therethrough the regulator  414  to the flame chamber  400 . In this form, the flame chamber unit can be positioned on the wall or various other places to provide a flame for aesthetic purposes as well as providing a certain amount of heat to the surrounding environment. 
     It should be noted that in one form there are three different types of phases or states that the oven can be in. One is where the flame acts as a heating element and the oven is functioning as an oven, the flame element is turned off but the secondary heaters (which in one form is in the chamber) and the base plate are activated to heat the food items. Or, if the flame is turned on, for visual effect and for the possible side effect of cooling the entire unit which can be a part of the control system, and the oven secondary heaters are turned off and not in operation. In the latter state the unit  20  is utilized more for aesthetic purposes. Shown herein is one form of carrying out the preferred embodiment where a stand-alone unit is shown. Of course other forms, such as a built-in unit, cabinet or other type of fixtures setting can be employed. 
     While the present invention is illustrated by description of several embodiments and while the illustrative embodiments are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants&#39; general concept.