Patent Application
20240191878
This invention relates to oven linings constructed from stone and to stone-lined ovens. In particular, the invention relates to stone-lined ovens of heat storage range cookers, and to range cookers incorporating stone-lined ovens.
The terms “stone” and “stone material” as used herein should be construed to encompass engineered stone, natural stone, concrete, clay, refractory cement, ceramics, masonry, cordierite, and other like materials.
Heat storage range cookers are traditionally made from cast iron coated with an aesthetic vitreous enamel finish. Cast iron is a material known for its high thermal mass, i.e. the ability to absorb and store heat. In addition to the provision of radiant heat for cooking, this high thermal mass also enables range cookers to provide residual heat into the room, thus serving a dual purpose as both cooker and room heater.
Range cookers provide a desirable form of cooking using radiant or indirect heat, as opposed to the standard fan assisted convection cooking utilised in most modern electric ovens. In range cookers, the heat charged iron ovens cook the food from all angles via an indirect heat source. This is considered to create superior results for roasting, baking and slow cooking. In addition, heat storage range cookers naturally vent the moisture inside the ovens creating a dry oven that cooks food without the condensation associated with convection ovens.
Traditional constructions of range cookers do however suffer from a number of shortcomings associated with the use of cast iron. These include the tendency for the iron to rust due to moisture in the air. In addition, a cast iron surface is difficult to thoroughly clean, meaning that it is somewhat unhygienic for food preparation, and can be unsightly. Although vitreous enamel coatings are generally used for external surfaces of range cookers, these are expensive and as a result the leading suppliers of range cookers generally do not use a food safe coating for the oven chamber, meaning that internal iron surfaces are usually left bare.
From an engineering perspective, cast iron is not a ‘true’ surface, meaning that it is common to incur wastage in castings through inconsistencies in cast dimensions. Moreover, building an oven from five iron panels—for base, top, rear, left side and right side—is highly labour intensive, and the casting process requires temperatures of 1200° C., giving it a high carbon footprint and making it environmentally unsound.
Further disadvantages of traditional models of range cooker include: high running costs, limited controllability, limited or no independent control between hobs and ovens, and excessive residual heat being emitted into the room in summer months. Still further, typical vitreous enamel coatings are prone to being easily tarnished, chipped and scratched. Traditional models, particularly those operating on oil, gas or solid fuel, often require a chimney, flue, combustion ventilation and adherence to multiple building control regulations in relation to flue termination, gas pipes, and oil lines. More recently, electrically operated models have been produced which address some of these issues, but over complicated and unreliable control systems have made some models unreliable.
The present invention seeks to address the above issues by constructing the oven chamber from stone materials in place of the traditional cast iron.
It is known to construct ovens with a stone base panel for direct heat, for example as used in pizza ovens. However, it is believed that hitherto, no oven has been disclosed that provides radiant cooking from all five internal panels of an oven chamber, using stone as a primary construction material.
Therefore, according to a first aspect of the present invention there is provided a lining construction for an oven, comprising a top panel, a base panel, a rear panel, and left and right side panels, wherein at least two of said panels are constructed from a stone material. Preferably, all five of said panels are constructed from a stone material.
The stone material may be selected from engineered stone, natural stone, concrete, clay, refractory cement, ceramics, masonry, cordierite, and other like materials, with engineered stone being most preferred.
Constructing the oven panels from a stone material provides a number of benefits over cast iron. In particular, the panels do not rust or tarnish, and present a wipeable, cleanable, food-safe tested surface, with no requirement for any additional coating or surface finishing. The panels can easily be replaced when required and, particularly when constructed from engineered stone, can be produced with no dimensional intolerances or wastage.
Whilst stone materials, in common with cast iron, have a high thermal mass, they are lighter than cast iron. Particularly when constructed from engineered stone, this allows for the production of panels with a thickness of substantially 20 mm, as opposed to the 6 mm thickness generally used for cast iron. This allows for superior distribution of heat, with fewer uneven ‘hot spots’.
In a preferred embodiment of the first aspect of the present invention, the lining construction comprises a structural framework in which the panels are assembled, thereby forming a lining cassette. The structural framework is preferably constructed from steel, and most preferably from mild steel.
The lining cassette may further comprise a layer of heat conductive material between the panels and the structural framework, to increase heat conduction and heat recovery. The heat conductive material preferably is or comprises graphite and/or graphene.
The construction of the stone oven lining as a lining cassette enables a standard modular construction of oven lining to be used with an array of different sizes and configurations of range cooker. These may typically have between one and four ovens, and the ovens themselves may vary in size. It is intended that the lining cassette will be adapted to slot into and engage with a housing or chassis of the range cooker.
As will be appreciated, the lining construction (as embodied by the lining cassette) according to the first aspect of the present invention as hereinbefore described only provides five sides of an oven chamber. The sixth side required to close the chamber is provided by a door when the lining construction is mounted in the housing of chassis of a range cooker, to form an oven.
Therefore, according to a second aspect of the present invention there is provided an oven having a top panel, a base panel, a rear panel, and left and right side panels, wherein at least two of said panels are constructed from a stone material, and further comprising a door forming a front panel, said door and said panels together defining an oven chamber. The said oven panels may preferably be provided in the form of a lining construction according to the first aspect of the present invention, wherein the door and the lining construction together define the oven chamber.
More preferably, the panels may be provided in the form of a lining cassette according to the preferred embodiment of the first aspect of the present invention, wherein the door and the lining cassette together define the oven chamber. In such embodiments, the oven preferably further comprises high density insulation pads arranged externally of the lining cassette, to retain the heat within desired areas.
The oven according to the second aspect of the present invention is preferably an electric oven, thus avoiding the need for chimneys, flues and combustion ventilation. The oven preferably comprises one or more electric heating elements, arranged such that the panels convey radiant indirect heat from said heating element to the oven chamber. The heating element is preferably located beneath the base panel, but may alternatively be located above the top panel. A perforated panel is preferably provided between the heating element and the base panel, or top panel, as appropriate.
According to a third aspect of the present invention there is provided a range cooker having one or more ovens according to the second aspect of the present invention. Said ovens preferably comprise a lining construction according to the first aspect of the present invention, and more preferably comprise a lining cassette according to the preferred embodiment of the first aspect of the present invention.
The range cooker may desirably have two ovens both heated by the same electric heating element. This may be achieved by arranging a top oven above a bottom oven, with the heating element being located under the base panel of the top oven and above the top panel of the bottom oven.
The range cooker preferably comprises a housing into which the lining cassette slots and engages thereby to provide the ovens. The housing is preferably constructed from steel, and more preferably from stainless steel. Stainless steel has a superior thermal mass to cast iron and has significant advantages in terms of durability, and resistance to corrosion. This also removes the need for an enamel coating to be provided over the external surface of the housing.
In order that the present invention may be clearly understood, a preferred embodiment thereof will now be described in detail, though only by way of example, with reference to the accompanying drawings, in which:
Referring first to
A structural framework 16 is provided, to which the stone panels 11 to 15 are secured during assembly, in order to form a lining cassette 20, as will be described in more detail below with reference to
A perforated panel 17 is provided beneath the base panel 12. When assembled to form an oven 40 in a range cooker 30, the perforated panel 17 overlies the heating element (not shown) and regulates the even flow of heat to the base panel 12 and around the other stone panels 11 and 13 to 15 defining the oven chamber 18.
Other components of the lining construction 10 shown in
Referring now simultaneously to
As can be seen, the upper surface of the structural framework 16, and the lower surface of the base support 23, are each provided with a pair of mounting brackets 21. These enable the lining cassette 20 to engage with and be secured in a housing 32 of a range cooker 32, as will be described in more detail below with reference to
Referring now simultaneously to
Each oven 40 has a door 31, which provides the sixth side of the oven chamber 18 defined together with the lining cassette 20 supporting the stone panels 11 to 15. The oven chambers 18 can be seen in
The housing 32 also has a fourth door 33, shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2105242.8 | Apr 2021 | GB | national |
| PCT/EP2022/059731 | Apr 2022 | WO | international |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/059731 | 4/12/2022 | WO |
