WO2010108273A1

WO2010108273A1 - Combined microwave and conventional oven

Info

Publication number: WO2010108273A1
Application number: PCT/CA2010/000445
Authority: WO
Inventors: Magdy Ayad Rizk
Original assignee: Magdy Ayad Rizk
Priority date: 2009-03-24
Filing date: 2010-03-24
Publication date: 2010-09-30

Abstract

There is described an oven for cooking at least one food item, comprising: a conventional heating chamber adapted to receive and conventionally heat the at least one food item; a microwave heating chamber adapted to receive and apply microwaves to the at least one food item; a conventional heating device in heat transfer communication with the conventional heating chamber; a microwave generator in microwave transfer communication with the microwave heating chamber; a conveyor extending through the conventional heating chamber and the microwave heating chamber, the conveyor adapted to receive and transport the at least one food item between the conventional heating chamber and the microwave heating chamber; and a control unit for controlling the non-microwave heating device, the microwave generator, and the conveyor.

Description

COMBINED MICROWAVE AND CONVENTIONAL OVEN

CROSS-REFERENCE TO RELATED APPLICATIONS

[001] This application claims priority under 35 USC 119 (e) of United States Provisional Patent Application bearing serial number 61/162,818 filed on March 24, 2009, the contents of which are hereby incorporated by reference .

TECHNICAL FIELD

[002] The present invention relates to the field of heating devices, and particularly to ovens combining microwaves and conventional heating.

BACKGROUND

[003] In the fast-food industry, time is an important factor and food has to be cooked rapidly so that customers wait a minimum of time for their meal. In order to reduce the cooking time, microwave cooking is often used in addition to conventional cooking. Taking the example of the cooking of a pizza, the pizza is first precooked in a microwave oven and then placed into a conventional oven. Alternatively, the microwave oven is used to defrost a frozen pizza and the conventional oven is used to cook it. The time taken to heat the pizzas in these ovens, coupled with the additional time required to transport the pizza from the microwave oven to the conventional oven increases the overall preparation time for the food item and therefore, the waiting time for the customers .

[004] Therefore, there is a need for an improved oven that minimizes customer wait times.

SUMMARY

[005] According to a first broad aspect, there is provided an oven for cooking at least one food item, comprising: a conventional heating chamber adapted to receive and conventionally heat the at least one food item; a microwave heating chamber adapted to receive and apply microwaves to the at least one food item; a conventional heating device in heat transfer communication with the conventional heating chamber; a microwave generator in microwave transfer communication with the microwave heating chamber; a conveyor extending through the conventional heating chamber and the microwave heating chamber, the conveyor adapted to receive and transport the at least one food item between the conventional heating chamber and the microwave heating chamber; and a control unit for controlling the non-microwave heating device, the microwave generator, and the conveyor .

[006] In accordance with another broad aspect, there is provided an oven for cooking a plurality of food items, the oven comprising a heating chamber for receiving the food items, a plurality of supports in the heating chamber for supporting the food items as they are being cooked, and a plurality of heating devices in heat transfer communication with the heating chamber, each one of the plurality of heating devices corresponding to a different heating type and adapted to be used simultaneously and sequentially with at least another one of the heating devices, the oven also comprising a conveyor in the heating chamber for displacing the food items within the heating chamber during the cooking, and a control unit connected to the plurality of heating devices and the conveyor, the control unit adapted to activate the plurality of heating devices in accordance with a cooking schedule by setting each one of the plurality of heating devices individually for start time, duration, and intensity.

[007] The expression "conventional oven" refers to any non- microwave oven. Convection ovens, infrared ovens, gas ovens, electric ovens are examples of conventional ovens . It should be understood that a conventional oven may use more than one conventional heating technology, i.e. non-microwave heating technologies, to heat food. For example, a conventional oven can be a convection oven provided with an infrared heating element.

[008] The expression "conventional heating" refers to any non- microwave heating technology.

BRIEF DESCRIPTION OF THE DRAWINGS

[009] Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0010] Fig. 1 is a schematic illustration of a combined microwave and conventional having a microwave chamber and a conventional chamber, each having a single food position, in accordance with an embodiment ;

[0011] Fig. 2a is a perspective view of a combined microwave and conventional oven with a one item loading/unloading station, in accordance with an embodiment;

[0012] Fig. 2b is a perspective view of a combined microwave and conventional oven with a three item loading/unloading station, in accordance with an embodiment;

[0013] Fig. 3 is a perspective view of the combined and conventional oven of Fig. 1 with a top cover removed, in accordance with an embodiment; [0014] Fig. 4 is a top view of the combined microwave and conventional oven with the top cover removed of fig. 2, in accordance with an embodiment;

[0015] Fig. 5 is a cross-sectional elevation view taken along cross-section lines A-A of Fig. 2, in accordance with an embodiment ;

[0016] Fig. 6 is a top view of the combined microwave and conventional oven of Fig. 2 covered by a top plate, in accordance with an embodiment;

[0017] Fig. 7 is a cross-sectional front view taken along cross- section lines A-A of Fig. 2, in accordance with an embodiment;

[0018] Fig. 8 is a perspective view of a conveyor, in accordance with an embodiment;

[0019] Fig. 9 is a top view of the conveyor of Fig. 7, in accordance with an embodiment;

[0020] Fig. 10 is a schematic illustration of an exemplary combined microwave and conventional oven with nozzles for humidifying the food items,-

[0021] Fig. 11 is a front view of an exemplary oven with two separate and circular plates for cooking multiple items.

[0022] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION

[0023] Figure 1 illustrates a combined microwave and conventional oven (CMCO) 1 for heating at least one food item. The CMCO 1 is provided with a conventional heating chamber 2 connected to a microwave heating chamber 3. The conventional heating chamber 2 is in heat transfer communication with one or more conventional heating devices 53. These conventional heating devices 53 can be located inside the chamber 2. Alternatively, these conventional heating devices 53 may be located outside the chamber 2 and the generated conventional heat is directed into the chamber 2. A microwave generator 55, such as a magnetron, is used for propagating microwaves in the chamber 3. A microwave barrier 4 preventing the microwaves from escaping the chamber 3 and propagating into the chamber 2 is located between the two chambers 2 and 3. A conveyor 5 extends through the two chambers 2 and 3. The conveyor 5 is adapted to receive and transport the food item between at least one position 6 in the conventional heating chamber 2 and at least one position 7 in the microwave heating chamber 3. The microwave barrier 4 is adapted to allow movement of the food item between the two chambers 2 and 3 via the conveyor 5. A control unit 51 is connected to the conventional heating device 53, the microwave generator 55, and the conveyor 5. The control unit 51 is used to control the temperature inside the conventional heating chamber 2, the power of the microwaves generated in the microwave heating chamber 3, the heating time in each chamber 2, 3, the speed and position of the conveyor 5, and the like. The control unit 51 can also control the movement of the microwave barrier 4.

[0024] In one embodiment, each chamber 2, 3 of the CMCO 1 is provided with a door 8. For example, the food item is placed in position 7 by opening the door 8 and giving access to conveyor 5 in the microwave heating chamber 3. Microwaves are applied to the food item for a predetermined period of time. Then, the conveyor 5 automatically transports the food item to the position 6 inside the conventional heating chamber 2 where the food item is conventionally heated. When the conventional heating is completed, a user removes the cooked food item through the door 8 of the chamber 2.

[0025] Figure 2a illustrates one embodiment of a CMCO 10 adapted to cook pizza cones. A pizza cone is equivalent to a pizza slice, having the shape of an ice cream cone. The CMCO 10 comprises a main frame 12 covered by a top portion 14. The main frame 12 is provided with a main door 16 and a sliding door 17 for accessing the interior of the CMCO 10. The main door 16 is provided with a window so that a user can monitor the cooking of the pizza cones. The sliding door 17 separates the load/unload deck or station 18 from the interior of the CMCO 10.

[0026] It should be understood that the sliding door can be replaced by any door allowing an automatic opening. For example, a revolving door can be used, or a pivot door.

[0027] Figure 2b illustrates an alternative embodiment for the load/unload station 18. In this embodiment, more than one food item is available at the deck at one time. A different shape is also illustrated for the housing of the CMCO 10.

[0028] As illustrated in figure 3, the main frame 12 comprises three heating chambers 20, 22, and 24. Heating chamber 20 is a conventional heating chamber which uses at least one conventional heating technology to heat the pizza cones while the heating chambers 22 and 24 are microwave heating chambers in which microwaves are propagated to heat the pizza cones. The microwave heating chambers 22 and 24 are connected together and they are each connected to the conventional heating chamber 20 so that a pizza cone can successively pass from the chamber 20 to the chambers 22 and 24, and come back into the chamber 20. A revolving door 26 having four partitions 28 at right angles to each other is positioned between the conventional heating chamber 20 and the microwave heating chambers 22 and 24. The revolving door 26 rotates about a central axis that is also the central axis of a semi-cylindrical shell. The two heating chambers 22 and 24 are separated from each other by one partition 28 of the revolving door 26. Each one of the heating chambers 22, 24 is also separated from the conventional heating chamber 20 by another one of the four partitions 28. The revolving door 26 acts as a microwave shield preventing the microwaves from propagating into the conventional heating chamber 20 and also preventing the microwaves propagating in the chamber 22 from propagating into the chamber 24, and vice versa. A conveyor, described in more detail below, receives a pizza cone at the load/unload station 18 and transports it stepwise to the microwave heating chambers 22, 24, and the conventional heating chamber 20.

[0029] In one embodiment, contacts are attached to each partition 28 of the revolving door 26 so that the application of microwaves in the heating chambers 22, 24 is stopped when the revolving door 26 is rotated.

[0030] It should be understood that the partitions 28 of the revolving door 26 can be made from any adequate type of material preventing the propagation of microwaves. For example, the partitions 28 can be made of stainless steel, aluminum, painted/plated steel, fiber carbon, and the like. In one embodiment, the material of the partitions 28 is conductive but non-magnetic. The material of the partitions can also be heat insulating material to prevent the conventional heat generated in the heating chamber 20 from propagating in the heating chambers 22 and 24. Alternatively, the material of the partitions 28 is heat conductive. In this case, a temperature sensor can be used for monitoring the temperature of the pizzas in the heating chambers 22 and 24 in order to determine the different heating parameters.

[0031] Any microwave barrier preventing the microwaves from propagating into the conventional heating chamber 20 while allowing the pizza cones to successively move through the chambers 20, 22, and 24 can be used. In one embodiment, the chambers 22 and 24 are each separated from the chamber 20 by a sliding door. A further sliding door separates the two microwave heating chambers 22 and 24. When a sliding door opens to allow a pizza cone to enter the chamber 22 or exit the chamber 24, the generation of the microwaves is stopped in the respective chamber 22, 24 until the sliding door is closed. In another embodiment, no microwave barrier is positioned between the chambers 22 and 24. In this case, the CMCO 10 is provided with a single microwave heating chamber that may be powered by one or more magnetrons .

[0032] Figure 4 illustrates the path followed by a pizza, cone during a cooking cycle. The pizza cone is moved in a stepwise manner through the chambers 20, 22, and 24. The pizza cone is received in the first position 32 of the cooking cycle in the load/unload station 18. The sliding door 17 opens and the pizza cone is taken from the first position 32 to the second position 34 in which the pizza cone is initially warmed-up and/or partially defrosted by the conveyor. After a predetermined time delay the conveyor transports the pizza cone to the third position 36 which is located in the microwave heating chamber 22. While the pizza cone is moved from the second position 34 to the third position 36, the revolving door 26 is rotated to allow the pizza cone to enter the microwave heating chamber 22. The next step is the displacement of the pizza cone from the third position 36 to the fourth position 38 which is located in the second microwave heating chamber 24. This displacement is accompanied by a rotation of the revolving door 26. A further rotation of the door and displacement of the conveyor brings the pizza cone in the fifth position 40 that is located in the conventional heating chamber 20. Then the conveyor moves the pizza cone from the fifth position 40 to the position 58 in a stepwise manner via positions 42 to 56. Finally, the sliding door 17 opens and the cooked pizza cone is brought back to the first position 32.

[0033] In one embodiment, a sensing device is used to determine if a pizza cone is present in the heating chambers 22 and 24 and microwaves are only generated in the heating chamber 22, 24 in which a pizza cone is present. Any adequate type of sensors, such as infrared sensors, can be used.

[0034] The cooking cycle described above allows automation of the cooking of multiple pizza cones. Each time a cooked pizza cone reaches the station 18, a user of the CMCO 10 can replace the cooked pizza cone by an uncooked pizza cone. In the embodiment illustrated in figure 4, the CMCO 10 can cook up to fourteen pizza cones in an automated manner. The user of the CMCO 10 does not have to transport the pizzas from an independent microwave oven to a separate conventional oven. This particular feature, in addition to the configuration/design of the microwave chambers 22 and 24, allows a reduction of the overall cooking time. Furthermore, as each pizza cone successively occupies each position 32-56, a uniform cooking may be provided from one pizza cone to another.

[0035] In one embodiment, an air curtain can be positioned in the vicinity of the door 17 in order to blanket the door opening and reduce the loss of heat when the door 17 is opened. The air curtain can be continuous or only activated when the door 17 is open. If it is intermittent, the air curtain can be controlled by a solenoid, for example. In one embodiment, the user can choose to keep the sliding door 17 in the open position with the air curtain activated.

[0036] Figures 5-6 illustrate some of the heating devices comprised in the CMCO 10. As illustrated in figure 5, some of the different conventional heating devices may be mounted above and below a heat distribution plate 60 of the CMCO 10. The heat distribution plate 60 is positioned on top of the chambers 20, 22, and 24, and below an insulating barrier at the bottom of the top cover 14. A conventional heating device 53 is located immediately above the heat distribution plate which also includes a fan 62. The fan 62 is used for circulating the heat generated by the conventional heating device into the chamber 20. In one embodiment, at least one magnetron 55 for generating microwaves in the chambers 22 and 24 is provided below a floor 68 and waveguides are used to guide the microwaves generated by the at least one magnetron 55 into the chambers 22 and 24.

[0037] Figure 6 illustrates one embodiment of the heat distribution plate 60 which comprises a main aperture 64 and a plurality of exit apertures 66. The main aperture 64 is located below the center of the fan 62 and causes the air to be drawn from the conventional heating chamber 20. The exit apertures 66 allow the air heated by the conventional heating element 53 surrounding the fan 62 to be returned to the conventional heating chamber 20. The fan 62 continually pulls air from the chamber 20 to heat the air to a desired temperature before being directed again into the conventional heating chamber 20 through the apertures 66 in the heat distribution plate 60. The fan 62 and the apertures 64 and 66 allow a constant flux of heat in the chamber 20, a substantially even distribution of the heat in the chamber, and an accelerated cooking of the pizza cones.

[0038] In one embodiment, the heat distribution plate 60 is free from any apertures on top of the microwave heating chambers 22 and 24 so that no conventional heating occurs in the chambers 22 and 24.

[0039] In another embodiment, instead of a fan, there is provided an electrically heated high velocity air stream blower, that can be controlled so that the impingement velocity on the food may be varied from 600 to 8000 feet per min (fpm) , or 10 to 133 feet per seconds (fps), over a period of time. This variable speed convection air will allow optimization of the heat transferred to the various foods being processed, and may be used to equalize the heat absorbed by the food and the conductance of the heat to the interior of the food. Programming of this process will allow the formation of a skin to keep in moisture followed by a reduced temperature with an increased air flow to maximize heat transfer in the more bulky foods being processed

[0040] Figures 7, 8 and 9 illustrate one embodiment of a conveyor for transporting the pizza cones. In this embodiment, the conveyor comprises two parts, a first one located inside the chambers 20, 22, and 24 and a second one located below a floor 68. The second part located below the floor 68 comprises a magnetic driving mechanism 70 while the first part is constituted of a plurality of cone bases 72. Each cone base 72 is sized to receive a pizza cone. The magnetic driving mechanism 70 comprises a belt 74 to which a plurality of magnetic bases 76 are secured at regular intervals. The belt 74 is driven by a pair of driving plates 78, each located at one end of the belt or path of the chain 74. At least one motor (not shown) rotates the sprockets 78 so that the pizza cones are moved in accordance with a moving schedule. Once the floor 68 is installed above the magnetic driving mechanism 70, the top surface of the magnetic bases 76 engages the bottom surface of the floor 68 or is at least in close proximity with the bottom surface of the floor 68. Each cone base 72 is positioned on top of a respective magnetic base 76. Each magnetic base 76 also includes a magnetic device for generating a magnetic field. Because of this magnetic field, each cone base 72 follows its corresponding magnetic base 76 during movement of the drive chain 74.

[0041] The rotation of the sprocket 78 drives the chain 74 and moves the magnetic bases 76 along the path described by the chain 74. Because of the coupled magnetic fields, each cone base 72 follows the path of its corresponding magnetic base 76 and successively occupies the positions 32-58 illustrated in figure 4. Such a magnetic conveyor allows the floor 68 to be seamless which facilitates the cleaning of the floor 68, prevents or minimizes any loss of heat which otherwise could leak into the space below the floor 68, and prevents any discharge of food onto the driving mechanism.

[0042] As illustrated in figure 5, the revolving door 26 is connected to the sprocket 78 located below the microwave heating chambers 22 and 24 via a mechanical or magnetic arrangement so that a rotation of the sprocket 78 rotates the revolving door. Alternatively, the revolving door 26 can be rotated by the metallic cone support 72 which pushes one of the partitions 28 of the revolving door 26 while it enters the chamber 22 or exits the chamber 24. In another embodiment, the revolving door 26 can be rotated by a motor independent of the driving plate 78.

[0043] The floor 68 can be made of any material which allows the magnetic field produced by the magnetic bases 76 to attract their respective cone base 72. For example, the floor 68 can be made of stainless steel. It should be understood that the material of the floor 68 should also be suitable for the microwave heating and for the conventional heating. The top surface of the floor 68 should be planar and smooth so that the cone bases 72 can slide thereon.

[0044] In one embodiment, the magnetic bases 76 have a star-shape as illustrated in figure 9. The frame 80 containing the magnetic driving mechanism 70 is provided with a plurality of cogs or catches 82 positioned along the path of the magnetic bases 76. In this embodiment, each magnetic base 76 is rotatably secured to the belt 74. Each time a branch of a magnetic base 76 engages a catch 82, the magnetic base is rotated. This rotation is linked to the corresponding cone base 72 by the magnetic field produced by the magnetic base 76. As a result, each cone base 72 rotates as it propagates in the chambers 20, 22, and 24. This particular feature ensures that the pizza cones will be evenly cooked. In the embodiment illustrated in figure 9, each star- shape magnetic base is an eight-point star and the frame 80 comprises catches between each position 32-58. It should be understood that one path between two following positions 32-58 may comprise no catch while another path between two following positions 32-58 may comprise a plurality of catches. As a result, each pizza cone may rotate from zero to 360 degrees while moving from one position 32-58 to the next one. It should be understood that any rotating device could be used to rotate the magnetic bases 76. For example, a motor positioned between the belt 74 and each magnetic base 76 may be used for rotating the magnetic base 76. It should be understood that the rotation of the magnetic bases 76 can be incremental, as illustrated in figure 9, or continuous.

[0045] In one embodiment, the magnet of each magnetic base 76 produces a 7 kilograms force which ensures that the corresponding metallic cone base 72 will follow any movement of the magnetic base 76 even in the hottest areas of the conventional oven.

[0046] It should be understood that any conveyor adapted to operate in both a conventional oven and a microwave oven can be used. For example, a rail can extend on top of the floor 68 in the chambers 20, 22, and 24 and the cone bases can be adapted to circulate on this rail. In this case, the materials of the rail and the cone bases should be suitable to be used in a conventional oven and a microwave oven.

[0047] In one embodiment, the cone base 72 is provided with a cone holder 83 adapted to receive the pizza cone, as illustrated in figure 7. The cone holder 83 can be made of any heat conductive material, such as quartz glass, in order to distribute the heat substantially evenly around the lower lateral surface of the pizza cone. [0048] In one embodiment, the cone base 72 is made of aluminum. It should be understood that the outline of the cone base 72 should be smooth and contain no pointed areas in order to avoid the generation of electric arcs in the chambers 22 and 24.

[0049] In one embodiment, illustrated in figure 10, at least one nozzle 102a is provided inside the CMCO 10. Humidity and moisture levels may be controlled by spraying demineralised water into the heated chamber 2 so that the food being processed may maintain an ideal moisture level. This keeps the food products from drying out and preserves the quality and texture of the heated/cooked food. The water vapor may be varied from full saturation of the chamber for products such as vegetables that are best steam cooked, to being shut off for very small finger fries that may be heated within 30 to 40 seconds. A second nozzle 102b may also be provided to have a spraying effect from more than one position inside the chamber 2. Additional nozzles may be provided as desired.

[005O]A control unit 51 is connected to the conventional heating device 53, the microwave generator 55, the conveyor 5, and an interface 84 illustrated in figure 2. Through the interface 84, a user can select the type of heating to be used, adjust the temperature of the selected heating technology, the power of the microwaves generated in the chambers 22 and 24, the speed of the conveyor, the time spent at any given position 32-58, etc. If the microwaves are not continuously generated in the chambers 22 and 24, the control unit may also be used to adjust the duration of the generation of the microwaves. The opening of the sliding door 17, the rotation of the revolving door 26, the air curtain, and the rotation of the magnetic bases 76 can also be controlled by the control unit . [0051] In one embodiment, the control unit 51 is a programmable logic controller (PLC) . The PLC can be programmed to control the movement of the conveyor, the operation of the heating devices, and the opening of the doors. High temperature limits can also be programmed to turn off the heating elements to avoid the pizza cones from becoming burned and to shut down the oven if the motor or controls become overheated.

[0052] It should be understood that the generation of the microwaves in the two chambers 22 and 24 can be controlled independently. For example, the power of the microwaves and/or the cooking time in the chambers 22 and 24 can be different. For example, the microwave generation can be continuous in the chamber 22 so that a pizza receives microwaves during the entire time it spends in the chamber 22, while microwave generation only occurs during half of the time the pizza spends in the chamber 24. Alternatively, identical settings can be applied to the microwave generation in both chambers 22 and 24 and the on/off cycling can be controlled by sensing the pizza exterior temperature .

[0053] In one embodiment, the conventional heating chamber 20 is provided with a radiant heater 86, such as an infrared heating device, as illustrated in figure 5. The radiant heater 86 is connected to and controlled by the control unit 51. A user can adjust parameters such as the temperature of the radiant heater, the operation time, etc via the interface 84. The radiant heater is used to adjust the firmness and the color of the pizza cones while they are located at positions 48-52, and to brown the food items to make them more acceptable aesthetically to the public. [0054] While some of the embodiments illustrated for the CMCO 10 are provided with a single conventional heating chamber 20 and two microwave heating chambers 22 and 24, it should be understood that the CMCO can be provided with a single microwave heating chamber 3 connected to the conventional heating chamber 2. This embodiment is illustrated in figure 11, where a separate rotating and sliding plate 110a, 110b, is provided in each one of the conventional heating chamber 2 and the microwave heating chamber 3. In this embodiment, the food items are displaced manually from the microwave heating chamber 3 to the conventional heating chamber 2, and vice versa. The plates 110a, 110b, rotate to expose the food items to the various heating devices provided in each chamber 2, 3, and are slidable to facilitate removal of the food items from inside the respective chambers. A plurality of supports are provided on each plate 110a, 110b, to allow multiple food items to be cooked/heated simultaneously.

[0055] Similarly, the CMCO could be provided with more than one conventional heating chamber and more than one microwave heating chamber. For example, a CMCO 10 can comprise a first conventional heating chamber connected to a second conventional heating chamber, and a microwave heating chamber connected to the second conventional heating chamber. The first and second conventional heating chambers can be provided with the same conventional heating technologies but the chambers can be heated at different temperatures. In this case, a heat barrier can be provided between the two conventional heating chambers . Alternatively, the first and second conventional heating chambers can be provided with different conventional heating devices. For example, the first conventional heating chamber may be heated by a convection heating device while the pizza is cooked by the infrared heating device in the second conventional heating chamber. In another embodiment, a CMCO can comprise a single microwave heating chamber sandwiched between two conventional heating chambers. The food item to be cooked is loaded in one of the conventional heating chambers before reaching the microwave heating chamber and finally the second conventional heating chamber.

[0056] In another alternate embodiment, the CMCO is provided with a single heating chamber having a conventional heating region and a microwave heating region. The microwave region is a region different from the conventional heating region and no microwave barrier separates the heating regions, as illustrated in figure 11. At least one conventional heating source is in heat transfer communication with the conventional heating region to conventionally heat the food items in this region. At least one microwave generator is in communication with the microwave heating region to apply microwaves to the food items. In this embodiment, a conveyor is used to move the food items between the conventional heating region and the microwave heating region.

[0057] In a further embodiment, the CMCO is provided with a single heating chamber which is used for conventionally heating and applying microwaves to the food items . At least one conventional heating device is in heat transfer communication with the heating chamber, and at least one microwave generator is in microwave transfer communication with the heating chamber. A plurality of conventional heating devices may be available for use in the heating chamber. One or more conveyors may extend through the heating chamber to move the food items inside the heating chamber. A control unit is used for controlling the conventional heating device, the microwave generator, and the conveyor (s) to heat the food item with the conventional heating device (s) and the microwave generator simultaneously or in a sequential manner. For example, the user may choose to have three types of heating used, two simultaneously followed by the third type. In another example, the user may choose to use only two types of heating, in a sequential manner. The selection of the type of heating, the duration of the heating, the intensity of the heating, all of which constitute an overall heating/cooking schedule, are all variable and may be set according to user preferences .

[0058] While the present description refers to a conveyor having an incremental or discontinuous movement which brings a pizza cone to a first position and waits for a certain time before moving the pizza cone to the next position, it should be understood that the movement of the conveyor can be continuous. In this case, the station 18 can be larger than the one illustrated in figure 2 in order to allow the user to remove the cooked pizza cone from the base 72 and insert an uncooked pizza cone while the base 72 is moving along the length of the load/unload station. This larger station can be separated from the chamber 20 by a large sliding door. Alternatively, two sliding doors located at opposite ends of the station can be used to allow a pizza cone to enter and exit the CMCO 10.

[0059] While the present description refers to convection heating provided in the chamber 20, it should be understood that any non-microwave heating technology or combination of non-microwave heating technologies can be used for heating the chamber 20. For example, the conventional heating chamber 20 can be a conventional electric oven. In this case, an electric coil heating element can be positioned below the plate 60. The electric coil heating element (s) is (are) positioned above the pizza cones and heats them.

[0060] While the previous description refers to a single load/unload deck 18, it should be understood that the CMCO can be provided with two separate decks, one for loading a pizza cone and the other one for unloading the pizza cone.

[0061] In one embodiment, a pizza cone is cooked in less than three and a half minutes thanks to the combination of the high velocity of the heated air in the conventional heating chamber 20, the infrared heating, and the microwave heating. It should be understood that this time limit may vary depending on the weight and the nature of the filling of the pizza cone.

[0062] While in the present description, the CMCO 10 is provided with fourteen positions 32-58, it can be provided with any number of positions. Similarly, it should be understood that the CMCO 10 can be provided with any number of cone bases 72 and magnetic bases 74.

[0063] In one embodiment, the control unit 51 is programmed to keep the pizza cones for about ten seconds in each position 32- 58, which provides enough time for the user to unload the cooked pizza cone when in the first position 32 and load an uncooked pizza cone.

[0064] In one embodiment, the main door 16 comprises a display such as a monitor or a TV screen. The display can be used to display movies, news, or the like in order to entertain customers while they are waiting for their meal. Alternatively, the display can be used for advertising purposes. The user of the CMCO can display the menu of the available food items. Alternatively, advertising for other merchants can be displayed.

[0065] While the present description refers to the cooking of pizza cones, the CMCO can be used to cook or heat (or a combination thereof) any food item such as pizza pockets, breads, a frozen meal contained in a container, fries, beverages, etc. In the case of pizza pockets, the cone bases 72 can be replaced by plate supports adapted to receive pizza pockets. In the case of the cooking of breads or meals contained in a container, the conveyor can be a conveyor belt extending inside a conventional heating chamber and a microwave heating chamber. The food item is received on the conveyor belt and transported in the two chambers .

[0066] The embodiments of the invention described above are intended to be exemplary only. In particular, any of the features illustrated in the attached drawings and described above may be used in various combinations thereof. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims .

Claims

CLAIMS :

1. An oven for cooking at least one food item, comprising: a conventional heating chamber adapted to receive and conventionally heat said at least one food item; a microwave heating chamber adapted to receive and apply microwaves to said at least one food item; a conventional heating device in heat transfer communication with said conventional heating chamber; a microwave generator in microwave transfer communication with said microwave heating chamber; a conveyor extending through said conventional heating chamber and said microwave heating chamber, said conveyor adapted to receive and transport said at least one food item between said conventional heating chamber and said microwave heating chamber; and a control unit for controlling said non-microwave heating device, said microwave generator, and said conveyor.

2. The oven of claim 1, further comprising a housing for said conventional heating chamber, said microwave heating chamber, said conventional heating device, said microwave generator, said conveyor, and said control unit.

3. The oven of claims 1 or 2 , further comprising a microwave barrier positioned between said conventional heating chamber and said microwave heating chamber to prevent propagation of said microwaves from said microwave heating chamber into said conventional heating chamber, said microwave barrier allowing movement of said at least one food item between said conventional heating chamber and said microwave heating chamber via said conveyor.

4. The oven of claim 3, wherein the microwave barrier is a revolving door.

5. The oven of any one of claims 1 to 4 , further comprising a loading/unloading station in fluid communication with at least one of the conventional chamber and the microwave heating chamber, the conveyor extending through the loading/unloading station to accept the at least one food item and transport it into one of the conventional heating chamber and the microwave heating chamber.

6. The oven of claim 5, further comprising a sliding door as a barrier between said loading/unloading station and said at least one of the conventional heating chamber and the microwave heating chamber.

7. The oven of claim 6, wherein the control unit is adapted to activate the sliding door in accordance with a rotation cycle for a food item circulating within said oven.

8. The oven of any one of claims 1 to 7 , wherein the conveyor comprises at least one support to hold the at least one food item as it is transported into the conventional heating chamber and the microwave heating chamber.

9. The oven of claim 8, wherein said at least one support is cone-shaped.

10. The oven of claim 8 or 9 , wherein the at least support rotates about a vertical axis as it advances through the conventional heating chamber and the microwave heating chamber.

11. The oven of any one of claims 8 to 10, wherein the control unit is adapted to displace the at least one support to a plurality of positions in the conventional heating chamber, and to at least one position in the microwave heating chamber, during one full rotation cycle.

12. The oven of any one of claims 8 to 11, wherein the control unit is adapted to stop the at least one support at each one of the plurality of positions for a predetermined amount of time.

13. The oven of any one of claims 8 to 12, wherein the control unit is adapted to displace the at least one support through the microwave heating chamber first, followed by the conventional heating chamber.

14. The oven of any one of claims 1 to 13 , wherein the microwave heating chamber comprises a first microwave area and a second microwave area partitioned by a barrier.

15. The oven of claim 14, wherein the barrier is a revolving door having four partitions at right angles to each other, two of the four partitions positioned between the conventional heating chamber and the microwave heating chamber, and one of the four partitions positioned between the first microwave area and the second microwave area.

16. The oven of claim 15, wherein the revolving door is activated by the conveyor as the at least one food item is moved into and out of the microwave heating chamber.

17. The oven of any one of claims 1 to 16, wherein the conventional heating device is above the conventional heating chamber, and further comprising a heat distribution plate extending between the conventional heating chamber and the conventional heating device and having a main aperture and a plurality of exit apertures, and a fan positioned above the heat distribution plate and substantially aligned with the main aperture, the fan pulling air from the conventional heating chamber through the main aperture, the exit apertures allowing air heated by the conventional heating device to be returned to the conventional heating chamber.

18. The oven of any one of claims 1 to 17, wherein said conveyor comprises a magnetic driving mechanism having a first component below an oven floor and a second component above the oven floor, the first component and the second component being magnetically coupled to displace the at least one food item through the conventional heating chamber and the microwave heating chamber.

19. The oven of claim 18, wherein the conveyor comprises a conveyor belt, the first component comprises at least one magnetic base secured to said conveyor belt and generating a magnetic field, and the second component comprises at least one metallic support positioned on top of said oven floor, said at least one magnetic base and said at least one support substantially aligned along a vertical axis so that said magnetic field attracts said at least one support through said oven floor, said at least one support following a displacement of said at least one magnetic base.

20. The oven of any one of claims 1 to 19, further comprising at least one blower for providing an electrically heated high velocity air stream inside the conventional heating chamber.

21. The oven of any one of claims 1 to 20, further comprising at least one nozzle for spraying a humidifying fluid inside the conventional heating chamber.

22. An oven for cooking a plurality of food items, the oven comprising a heating chamber for receiving the food items, a plurality of supports in the heating chamber for supporting the food items as they are being cooked, and a plurality of heating devices in heat transfer communication with the heating chamber, each one of the plurality of heating devices corresponding to a different heating type and adapted to be used simultaneously and sequentially with at least another one of the heating devices, the oven also comprising a conveyor in the heating chamber for displacing the food items within the heating chamber during the cooking, and a control unit connected to the plurality of heating devices and the conveyor, the control unit adapted to activate the plurality of heating devices in accordance with a cooking schedule by setting each one of the plurality of heating devices individually for start time, duration, and intensity.

23. The oven of claim 22, wherein the plurality of heating devices are selected from a group comprising of microwaves, convection, gas, infrared, electric, and air.