GB2607045A

GB2607045A - Oven

Info

Publication number: GB2607045A
Application number: GB2107486.9A
Authority: GB
Inventors: Jackson Andrew
Original assignee: Lincat Ltd
Current assignee: Lincat Ltd
Priority date: 2021-05-26
Filing date: 2021-05-26
Publication date: 2022-11-30
Also published as: GB2607132B; GB202107486D0; GB2607132A; GB202116874D0

Abstract

An oven defines an oven cavity 2 for receiving a food product and comprises a housing 1, a door, at least three means for heating and a controller. The means for heating comprises an oven element 3 provided in a top section of the oven, a radiant base element 4 and a microwave source. The oven cavity has a base 5 with a ceramic surface heated by the base element. The housing comprises a floor section 6 located between the ceramic base and the base element and the floor section comprises a metal body provided with apertures (7, Fig 2). The ceramic base may be ceramic glass. Preferably microwaves enter the oven cavity from a wall located opposite the door of the oven. A fan may be provided in the top section of the oven and in fluid communication with the oven cavity for moving air heated by the oven element within the oven cavity. The controller is configured to use the heating means independently, simultaneously or sequentially. The housing, the door and a waveguide provide a Faraday cage and the ceramic base of the oven cavity is located inside the Faraday cage.

Description

The present disclosure relates to an oven, in particular to an oven comprising a plurality of independently operable and co-operable heating means and a controller for controlling the operation of the heating means.

Various heating apparatus exist including convection ovens, contact grills and pizza ovens which use a single heating source. Some apparatus exist which combine various types of heating including accelerated heating apparatus which also use 10 microwaves to shorten cooking time.

The present invention arose with the aim of providing an improved oven which would allow different types of food, including pizzas and sandwiches, to be heated quickly, evenly and safely with better quality.

According to the present invention in one aspect there is provided an oven defining an oven cavity for receiving a food product for heating, the oven comprising a door for closing the oven cavity, at least three means for heating and a controller for controlling the operation of the heating means, wherein the means for heating comprises an oven element provided in a top section of the oven, a base element provided in a base section of the oven and a microwave source, the oven cavity has a base which is ceramic and defines a heating surface which is arranged to be heated by the base element in use of the oven, the base element is at least one radiant element, a metal body provided with apertures is located in the base section of the oven and is located between the ceramic base of the oven cavity and the base element, and the metal body lies over at least part of the base element.

According to the present invention in another aspect there is provided an oven defining an oven cavity for receiving a food product for heating, the oven comprising a door for closing the oven cavity and means for heating and a controller for controlling the operation of the heating means, wherein the means for heating consists of an oven element provided in a top section of the oven, a base element provided in a base section of the oven and a microwave source, the oven cavity has a base which is ceramic and defines a heating surface 5 which is arranged to be heated by the base element in use of the oven, the base element is at least one radiant element, a metal body provided with apertures is located in the base section of the oven and is located between the ceramic base of the oven cavity and the base element, and the metal body lies over at least part of the base element.

According to the present invention in a further aspect, there is provided an oven defining an oven cavity for receiving a food product for heating, the oven comprising a housing, a door for closing the oven cavity, at least three means for heating and a controller for controlling the operation of the heating means, wherein the means for heating comprises an oven element provided in a top section of the oven, a base element provided in a base section of the oven and a microwave source, the oven cavity has a base which is ceramic and defines a heating surface 20 which is arranged to be heated by the base element in use of the oven, the base element is at least one radiant element, the housing comprises a floor section located between the ceramic base of the oven cavity and the base element, and the floor section comprises a metal body provided with apertures, and the metal body lies over at last part of the base element.

The metal body provided with apertures is impermeable to microwaves. It provides a metal surface. The metal body is sandwiched between the ceramic base of the oven cavity and the base (radiant) element. Preferably, no components of the oven, other than the metal body, are located between the ceramic base and the base element.

The metal body lies over the base element to cover at least part of the side of the base element facing the metal body. In use of the oven, this side of the base element is its upper side, this upper side facing the lower side of the metal body. The upper side of the metal body faces the lower side of the ceramic base of the oven cavity. The upper side of the ceramic base is exposed to the oven cavity.

The metal body may lie substantially over a radiating area of the base element. The radiating area is the region or regions of the base element that are configured to radiate heat in use of the oven.

The apertures in the metal body provide for the transfer of heated air from the base element to the ceramic base of the oven cavity. The apertures in the metal body may be in one or more regions which are substantially aligned with the base element. In particular, the apertures in the metal body may be in one or more regions which are substantially aligned with the radiating area of the base element.

The base element may extend over more than 80% of the whole surface area of the ceramic base of the oven cavity. The metal body preferably extends substantially over the radiating area of the base element.

Preferably, the base element is not in direct thermal contact with the ceramic base of 20 the oven cavity.

The oven of the present invention may be provided with more than one base element.

The base element may consist of one or two radiant elements.

In one embodiment, a central region of the metal body is provided with apertures.

The ceramic base of the oven cavity may be ceramic glass or may be another ceramic material, for example, a material used to make baking stones, which are typically made of fired clay.

The material used for the ceramic base of the oven cavity is selected to provide mechanical stability to the housing of the oven and to be heated without distortion.

The ceramic base of the oven cavity may be fixed in the oven cavity or removable from the oven cavity, revealing the metal body (with apertures) beneath it.

Power to the base element is preferably either continuous, pulsed or regulated by a 5 thermocouple or a temperature sensor (and controlled to a set temperature).

The microwave source may comprise a magnetron concealed in the oven: for example, the magnetron is concealed in a top section or wall of the oven.

The microwave source may also comprise a waveguide which directs the microwave energy generated by the magnetron into the oven cavity. The waveguide therefore has an entrance for microwaves and an exit for microwaves. The entrance is provided at the magnetron. The exit is provided in a surface of the oven cavity, preferably through one or more apertures provided in the surface for this purpose.

The aperture or apertures may be provided with a glass cover. The surface is preferably a wall surface.

In one embodiment, microwaves are arranged to enter the oven cavity, in use of the oven, from a wall located opposite the door of the oven: they are thereby rearm launched.

In a preferred embodiment, the oven comprises a housing which comprises a floor section, three wall sections and a ceiling section, said sections comprising or consisting of metal bodies, provided with or without apertures. One or more of these sections of the housing may be in the form of a panel or sheet. The or each metal body may be a metal panel or metal sheet, provided with or without apertures.

Preferably, the floor section comprises, and may consist of, the metal body provided with apertures. The metal body provided with apertures may therefore be a floor section of the oven housing.

The metal bodies of the housing, together with the oven door and the waveguide, are configured to contain microwave energy within the oven and to prevent leakage of microwave energy.

The apertures in the metal body or metal bodies may comprise perforations in the metal body or metal bodies. In one example, a perforated metal panel is provided as a metal body with apertures. The metal body or some or all of the metal bodies may have one or more regions provided with apertures and one or more regions provided without apertures. The metal body or metal bodies may be of stainless steel or mild steel.

The oven thereby comprises a Faraday cage, formed in this embodiment by the 10 housing, the door and the waveguide. The Faraday cage retains the microwave energy within the oven. The oven cavity is located inside the Faraday cage. The ceramic base is located inside the Faraday cage.

The door may comprise a metal mesh or other means to contain microwave energy 15 within the oven and to prevent leakage of microwave energy.

Preferably, the ceiling section of the housing separates the top section of the oven from the oven cavity and comprises a metal body provided with apertures. The apertures assist with allowing heated air to pass from the oven element into the oven cavity, without allowing microwave energy to leak from the oven cavity.

The oven may further comprise a fan provided in the top section of the oven in fluid communication with the oven cavity for moving air heated by the oven element within the oven cavity.

The fan may be in fluid communication with the oven cavity via one or more apertures, nozzles, vents and/or ducts (by way of example).

The oven element may be configured to surround the fan The oven element may be at least one substantially circular element or substantially annular element.

In one embodiment, the oven element consists of two substantially circular elements or substantially annular elements. The circular/annular elements may be concentric. The provision of two circular/annular elements provides adjustment of the heating power of the oven. In this respect, the heating power may be reduced by using a single circular/annular element and may be increased by using both circular/annular elements.

The oven element may be a sheathed element or elements and is preferably a tubular sheathed element or elements.

The means for heating may comprise an additional oven element as an alternative or additional means for adjusting (ie reducing/increasing) the heating power of the oven. The additional oven element may be provided in the top section of the oven.

The oven cavity is preferably cubic or cuboid in shape and is defined by three wall surfaces, the door, one ceiling surface and the ceramic base.

The wall surfaces may be the wall sections of the housing. The ceiling surface may be the ceiling section of the housing.

The controller is preferably configured in any heating cycle either to use the heating means independently or sequentially or to use two or more of the heating means simultaneously.

By providing multiple heating means and controlling their use (both simultaneous and asynchronous) it is possible to optimise and accelerate heating whilst also reducing peak power consumption. Different types of food may be cooked in a reduced time with the phased use of the different heating means optimised for the food being heated during any heating cycle. Different combinations/sequences of the heating means may be used for different foods to reduce cooking times.

In this respect, the microwaves enable food to be heated internally while the oven element and the base element enable food to be heated to turn it crisp and brown on its upper and lower surfaces and sides, while heating it externally.

Non-limiting embodiments will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 shows a perspective view of internal components of an oven according to an embodiment of the present invention; Figure 2 shows a perspective view of internal components of an oven in accordance with Figure 1 but with the ceramic base removed; and Figure 3 is an exploded schematic side view of a base assembly of an oven.

With reference to the figures, there is shown an oven housing 1 and an oven cavity 2 for receiving a food product for heating.

The oven comprises the housing 1, a door (not shown) for closing the oven cavity 2, at least three means for heating and a controller (not shown) for controlling the operation of the heating means.

One heating means is an oven element 3 provided in a top section of the oven. Another heating means is a base element 4 provided in a base section of the oven.

A further heating means is a microwave source (not shown) arranged to launch microwaves from a wall of the oven via a waveguide, this wall being located opposite the door of the oven in this example, such the microwaves are rear-launched. The microwaves may instead be launched from a different surface of the oven cavity.

The base element 4 is provided under a ceramic base panel 5 that defines a base of the oven cavity. In the present arrangement the panel is formed from ceramic glass. It is not limited as such. For example, it could comprise alternative ceramic materials. The ceramic base of the oven cavity provides a heating surface which is heated by the base element 4. It is particularly suited to the heating of pizzas The housing 1 comprises a floor section 6 located between the ceramic base 5 of the oven cavity and the base element 4, and the floor section comprises a metal body provided with apertures 7 for the transfer of heated air. In the example shown, the apertures 7 are perforations located in a central region only of the floor section 6 which is in the form of a panel. The perforations are substantially aligned with the radiating area of the base element, in this example.

The base element 4 is a radiant element. The oven element 3 is a sheathed element which may be tubular. Such radiant elements and sheathed elements may take any conventional form or construction and the present invention is not to be limited to the specific form and construction of these elements. In the present arrangement, however, the base element is a fast-heat radiant element and the oven element is a metal sheathed element.

The oven element 3 may be circular or annular and may comprise one or more separate heating sections; for example, the oven element may be a sheathed element comprising two, three or four separate heating sections.

It is preferable that means is provided for moving air heated by the oven element within the oven cavity. In the arrangement shown, a fan 8 is provided for this purpose. The oven element 3 surrounds the fan 8 in this embodiment although this is not visible in the figures. The fan is in fluid communication with the oven cavity.

The fan 8 is preferably configured to draw air from the oven cavity via apertures provided in the ceiling section of the oven housing, to blow this air over the oven element and to blow air into the oven cavity via the apertures in the ceiling section. In this way, air trapped in the oven cavity 2 when the oven door is shut is heated and recirculated by the fan 8.

An octagonal cover 9 is provided in this embodiment to direct the air heated by the oven element through one or more vents down the sides of the oven cavity 2, over the food and back into the centre of the oven in a substantially symmetrical manner. The octagonal cover is located around and above an annular oven element 3 in this embodiment. In other embodiments, the cover may be circular, rectangular or square in shape, for example.

The oven comprises a catalytic converter in this embodiment. The catalytic converter is preferably provided in the top section of the oven. The catalytic converter is preferably provided externally of the Faraday cage, although it may form part of the Faraday cage as it is perforated.

The housing 1 comprises the floor section 4, three wall sections 10 and a ceiling section 11, said sections comprising metal bodies, provided with apertures if required.

The ceiling section comprises a metal body provided with apertures for the transfer of heated air into the oven cavity 2 from the oven element 3.

At least two of the heating means will preferably be used in any heating cycle (simultaneously or asynchronously or a combination of both). The use of at least two different heating means allows for optimised/accelerated cooking. The base element and/or a microwave source may be used simultaneously with the oven element. The controller may be configured in any heating cycle to use one or more of the base element or the microwave source.

In dependence on the food to be heated, different heating means may be used (in different combinations and/or sequences) during heating cycles to give the best result for different food types. A pre-heating step may be included or omitted in any heating cycle.

The controller may be user programmable such that the user can select which of the heating means are turned on, in which sequence/combination and for how long. The controller may additionally or alternatively be provided with a number of predefined user selectable programmes/programme stages, such as pizza, sandwich, etc. to allow user-friendly optimised and focused heating of a wide range of different products.

The controller preferably monitors the oven air temperature but could also or alternatively monitor the temperature of the base element. However no temperature sensor is provided in direct thermal contact with the ceramic base of the oven cavity as this would interfere adversely with the microwave radiation since any such temperature sensor would be inside the Faraday cage.

The oven is most preferably provided with one or more baking shelves (for foods not to be heated directly on the base). Any of the shelves may be fixed or more preferably height adjustable in the conventional manner.

Numerous variations and modifications will be readily conceived by those skilled in the art, within the scope of the present disclosure. Various combinations of heating means will be readily conceived by those skilled in the art, including the introduction of any known heating means suitable for use in an oven but not specifically referenced herein. In this respect, a grill element may be provided in the oven but in a preferred embodiment the oven of the present invention does not comprise a grill element.

Various alternative controller configurations providing different combinations and/or 15 sequences of any of the heating means provided in the oven may be implemented.

Claims

Claims 1. An oven defining an oven cavity for receiving a food product for heating, the oven comprising a door for closing the oven cavity, at least three means for heating and a controller for controlling the operation of the means for heating, wherein the means for heating comprises an oven element provided in a top section of the oven, a base element provided in a base section of the oven and a microwave source, the oven cavity has a base which is ceramic and defines a heating surface which is arranged to be heated by the base element in use of the oven, the base element is at least one radiant element, a metal body provided with apertures is located in the base section of the oven and is located between the ceramic base of the oven cavity and the base element, and the metal body lies over at least part of the base element.
2. An oven as claimed in claim 1, wherein the metal body lies substantially over the region or regions of the base element that are configured to radiate heat in use of zo the oven.
3. An oven as claimed in claim 2, wherein the apertures in the metal body are provided in one or more regions which are substantially aligned with the region or regions of the base element that are configured to radiate heat in use of the oven.
4. An oven as claimed in any preceding claim, wherein the ceramic base of the oven cavity is ceramic glass.
5. An oven as claimed in any preceding claim, wherein microwaves are arranged 30 to enter the oven cavity, in use of the oven, from a wall located opposite the door of the oven.
6. An oven as claimed in any preceding claim, comprising a housing which comprises three wall sections, a floor section and a ceiling section, wherein the floor section comprises the metal body provided with apertures.
7. An oven as claimed in claim 6, wherein the ceiling section separates the top section of the oven from the oven cavity and comprises a metal body provided with apertures.
8. An oven as claimed in any preceding, further comprising a fan provided in the 10 top section of the oven and in fluid communication with the oven cavity for moving air heated by the oven element within the oven cavity.
9. An oven as claimed in claim 8, wherein the oven element is configured to surround the fan
10. An oven as claimed in any preceding claim, wherein the oven element is at least one substantially circular element or substantially annular element.
11. An oven as claimed in any preceding claim, wherein the oven element is at least one sheathed element.
12. An oven as claimed in claim 11, wherein the oven element is at least one tubular sheathed element.
13. An oven as claimed in any preceding claim, wherein the controller is configured in any heating cycle either to use the heating means independently or sequentially or to use two or more of the heating means simultaneously.
14. An oven as claimed in any preceding claim, wherein the housing, the door and a waveguide provide a Faraday cage and the ceramic base of the oven cavity is located inside the Faraday cage.