FIELD

[01] The present invention relates to a portable oven. More specifically, the present invention relates to a portable wood-fired oven.

BACKGROUND

[02] Ovens can be found in many different forms, including electric ovens, gas ovens and wood-fired ovens. Wood-fired ovens can be favoured due to the fast rate of cooking and the distinctive flavour that can be imparted onto the foodstuff.

[03] Wood-fired ovens are commonly permanently fixed ovens formed of a brick enclosure covering a cooking surface to form a partially enclosed cooking chamber having a mouth for insertion of the foodstuff into the chamber. To reach the desired cooking temperature, wood is burnt in the cooking chamber. Once the desired cooking temperature is reached the remaining wood or residues thereof is generally pushed toward the side of the cooking chamber to allow foodstuff to be placed in the chamber. The mixed use of a single surface for heating and cooking means that good heat retention is important to provide a short heating time and a long cooking time. Fixed ovens formed of brick may provide good heat retention but offer little flexibility of location for use and can require substantial space.

[04] Wood-fired ovens formed from materials such as metal as the main structural component can allow for the construction of smaller ovens than brick based ovens but such ovens can still be heavy due to the amount of material required to provide sufficient stability in use. They can also suffer from reduced heat retention, for example due to the conduction of heat away from the cooking chamber, increasing the heating time and reducing the cooking time. Heat conduction may also present a safety risk due to a hot exterior surface, and lead to warping due to repeated heating and cooling. Reducing such risks may require the use of expensive outer protective coverings, further increasing the complexity of the manufacturing process and adding to the weight of the oven.

[05] It is also desirable to use portable ovens on a variety of support surfaces, including surfaces not designed for heat resistance. However, the close contact of a high temperature cooking surface with an untreated surface can result in damage to the surface. Spacing the cooking surface from support surface can reduce heat damage, however spacing the cooking surface can also reduce heat retention.

[06] Heat retention can also be significantly affected by the presence of a chimney, which can cause undue loss of heated air before an efficient amount of thermal energy has been transferred to the internal oven surfaces.

[07] It is therefore an object of aspects of the present invention to address on or more of the abovementioned or other problems. SUMMARY

[08] According to a first aspect of the present invention there is provided an oven, suitably a wood-fired oven, comprising: a cooking chamber portion; a head portion comprising a mouth; a chimney portion comprising a chimney inlet; and a cooking surface; wherein the chimney portion further comprises an airflow redirection member that spaces the chimney inlet vertically above and laterally back toward the cooking chamber from the mouth, wherein the airflow redirection member is operable to cause heated airflow originating from the cooking chamber portion to flow toward the cooking surface.

[09] An internal face of the airflow redirection member may comprise a sloped portion, such as a curved portion, operable to redirect heated airflow originating from the cooking chamber portion to flow toward the cooking surface.

[10] The oven may be a two-part oven such that the cooking chamber portion has different dimensions to the head portion. It will be understood that in such a two-part oven, the cooking chamber and the head portion have different internal macrostructures, and may have different internal and external macrostructures, such as the cooking chamber having a domed internal (and optionally external) macrostructure and the head portion having an internal (and optionally external) hemi-cylindrical macrostructure.

[11] The cooking chamber portion may have a bigger largest width than the average width of the head portion.

[12] An internal face of the cooking chamber may be curved, such as substantially all of the internal faces of the cooking chamber may be curved, for example the internal face of the cooking chamber may be substantially domed. A domed cooking chamber may be an ellipticalbased dome, such as a circular-based dome.

[13] The chimney portion may extend over at least a part of the head portion, and the chimney portion extending over the head portion may have a smaller average width than the average width of the head portion.

[14] The chimney portion may be fluidly connected with the cooking chamber so that the flow path of the heated air passing from the highest point of the cooking chamber to the airflow redirecting member is substantially linear. [15] The airflow redirection member may space the chimney inlet vertically above the mouth by at least 3cm, such as at least 5cm, or at least 7cm, or at least 10cm. The vertical spacing between the mouth (such as the highest point of the mouth) and the chimney inlet may be at least 5% of the largest internal vertical dimension of the cooking chamber, such as at least 10%, at least 15%, at least 20% or at least 25%.

[16] The airflow redirection member may space the midpoint of the chimney inlet laterally back toward the cooking chamber from the mouth by at least 3cm, such as at least 5cm, or at least 7cm, or at least 10cm.

[17] The internal length of the head portion may be at least 2% of the total internal length of the oven, such as at least 5%, or at least 10%.

[18] Advantageously, the airflow redirection member of any aspect of the present invention prevents the heated airflow from rising directly out of the chimney portion by reflecting the heated airflow originating from the cooking chamber portion toward the cooking surface, thereby improving heat retention. This in turn increases the fuel efficiency of the oven by reducing the heating and increasing cooking time.

[19] The oven may comprise a cover extending over the cooking surface such as to form a cooking chamber portion, head portion and a chimney portion with the cooking surface. Preferably, the oven further comprises a base for supporting the cooking surface.

[20] The base of the oven of any aspect of the present invention may comprise an insulation layer arranged between the cooking surface and the base.

[21] The cooking surface of the oven of any aspect of the present invention may be formed of a tile, suitably an integrally formed tile or two or more discrete tiles, preferably a single integrally formed tile. The tile may be formed of stone or ceramic, such as refractory ceramic fibres.

[22] The cover of the oven of any aspect of the present invention may comprise a liner. Suitably, the liner is attached to, preferably directly attached to, the inner face of the cover, more preferably over the inner face of the cover arranged in the cooking chamber. The lining is preferably an insulating and/or heat resistant lining. Suitably, the lining is a multi-layered lining and may comprise an insulation layer and a heat resistant layer. The insulation layer may be formed of ceramic, such as ceramic fibre. Preferably, the insulation layer has a density of between 80 and 170kg/m ² , such as between 90 and 160kg/m ² or between 100 and 150kg/m ² or between 110 and 140kg/m ² , for instance 120 and 135kg/m ² . Suitably, the insulation layer can withstand temperatures of between 900 and 1600°C, such as between 1000 and 1500°C, or between 1100 and 1400°C, such as between 1200 and 1300°C. The insulation layer may be a ceramic fibre insulation blanket. For example VITCAS ceramic blanket. The heat resistant layer may be formed of a course heat resistant material, such as crushed firebrick cement, and/or a fine heat resistant material such as fine screed. [23] The cover of the oven of any aspect of the present invention may comprise a plurality of projections extending into the liner such as to attach the liner to the cover. The liner may comprise a binding layer and preferably the projections are attached at a first end to the cover and at a second end to the binding layer. Suitably, the binding layer is an intermediate layer in the liner, preferably arranged between an insulating layer proximate to the cover and a heat resistant layer distal to the cover. The binding layer may be attached to a second end of the projections and also to the heat resistant layer. In such a manner, preferably the binding layer is operable to attach the liner to the cover. The binder layer may comprise a plurality of apertures, suitably the binder layer comprises a mesh, preferably a metal mesh. Advantageously, the liner attachment system of the present invention provides an effective method of fixing the lining to the cover whilst also fixing the heat resistant layer to the insulation layer.

[24] The mouth of the oven of any aspect of the present invention may be in the form of an aperture operable to permit the passage of foodstuffs into and out of the cooking chamber of the oven. The mouth is preferably arranged on a side face of the oven.

[25] The mouth of the oven of any aspect of the present invention may be provided by a mouth plate having an aperture. Suitably, the mouth plate is arranged over the cover. Preferably, the mouth plate is formed of a more heat resistant material than the material of the cover, such as a more heat resistant metal, for example stainless steel. The mouth plate may comprise a layer of insulation between the mouth plate and the cover. Suitably, the side face of the oven comprising the mouth is substantially planar. The lower edge of the mouth may be substantially flush with the upper edge of the cooking surface. Preferably, the mouth is hemispherical.

[26] Suitably, the mouth and chimney portion of the oven of any aspect of the present invention are operable to provide the only means for fluid communication between the cooking chamber and the external atmosphere. As such, preferably the cooking chamber is enclosed apart from the mouth and chimney portion.

[27] The mouth of any aspect of the oven of the present invention may comprise a lip arranged on the upper edge of the mouth, the preferably lip extending outwardly from side face of the oven.

[28] The lip of the oven of any aspect of the present invention may extend substantially perpendicularly outwardly from the side wall of the oven. Preferably, the lip is arched. The lip may be formed of a more heat resistant material than the cover of the oven. Preferably the lip is formed of metal. More preferably, the lip is integrally formed with the mouth plate. By ‘more heat resistant’ as used herein with respect to the material of the lip of the oven it is meant that the material is able to tolerate high temperatures before degradation or deformation. [29] The lip may have a depth of up to 10cm, such as 7cm, 5cm or 3cm. The lip may have a depth that is significantly greater than its height. For instance the lip may have a depth to height ratio of between 100:1 and 2:1 , such as between 75:1 and 3:1 , or between 50:1 and 4:1 , or between 30:1 and 5:1. Preferably, the depth of the lip is tapered, suitably the depth of the lip reduces from a largest depth at the portion of the lip arranged highest on the side face of the oven to smaller depths as the lip extends lower down the side face of the oven, suitably to a smallest depth at the portion of the lip lowest on the oven. Preferably, the lip has a substantially constant height.

[30] The skirt of the oven of any aspect of the present invention may extend downwardly from the peripheral edge of the cooking surface. Suitably, the skirt extends around substantially all of the peripheral edge of the cooking surface. Preferably, the skirt is arranged substantially outside of the peripheral edge of the cooking surface.

[31 ] The skirt of the oven of any aspect of the present invention preferably delineates the side walls of a cavity extending beneath the cooking surface. Preferably, the cavity is free of heat production members in fluid communication with the cooking chamber of the oven. Suitably, the cavity is a substantially open-bottomed cavity.

[32] The oven of any aspect of the present invention may comprise one or more handles for lifting and carrying the oven. Preferably, the handles are integrally formed with the skirt. The skirt may comprise a cut-away portion operable to be used as a handle. Preferably, the cutaway portion is open along at least one side, preferably a lower side of the cut-away portion is open. The skirt may comprise at least two cut-away portions operable to be used as handles, such as at least two pairs of opposed cut-away portions. Suitably, the skirt comprises substantially opposed cut-away portions on opposite side of the cooking surface.

[33] The skirt of the oven of any aspect of the present invention may restrict fluid communication between the external atmosphere and the cavity arranged underneath the cooking surface. For instance, the skirt may restrict the flow of gases from outside of the oven into the cavity. The skirt may enclose the cavity such that substantially all fluid communication with the cavity through a side wall of the oven is prevented.

[34] Suitably, between 30 and 100% of the surface area of the skirt is closed such as to block fluid communication between the external atmosphere and the cavity arranged underneath the cooking surface, such as between 40 and 99%, between 50 and 98%, between 60 and 97%, between 65 and 96%, between 70 and 95%, between 75 and 94% or between 80 and 93%, or between 85 and 92%.

[35] Optionally, only the cut-away portion of the skirt allows fluid communication with the cavity through a side wall of the oven. Suitably, the cut-away portion(s) comprise in total between 2 and 70% of the surface area of the skirt, such as between 3 and 50%, between 4 and 40%, between 5 and 30%, between 6 and 25%, between 7 and 20%, between 7 and 15% or between 7 and 10%.

[36] The skirt raises the cooking surface from the support surface on which the oven is placed in use. The support surface may be any suitable surface operable to support the weight of the oven, such as a work top or table.

[37] Advantageously, this arrangement allows for reduced heat damage to the support surface as a result of the raised cooking surface in combination with improved heat retention provided by the skirt due to restricted fluid flow in the area under the cooking surface and the airflow redirection member by reflecting the heated airflow originating from the cooking chamber portion toward the cooking surface.

[38] The bottom edge of the skirt of the oven of any aspect of the present invention may be at least partially linear, wherein the linear portion of the bottom edge of the skirt is operable to form a close fit abutment with a planar support surface. Preferably, substantially all of the bottom edge of the skirt apart from the cut-away portions is linear.

[39] The oven of any aspect of the present invention is operable to be heated by any suitable fuel source, such as wood and/or gas. Preferably the oven is a wood-fired oven, such that the oven burns wood as the fuel source. More preferably, the oven is a black-type wood-fired oven, such that the wood fuel is burnt in the cooking chamber. As such, preferably the oven of the present invention is not a white-type oven, namely an oven that is heated by heat transfer from a separate combustion chamber and flue-gas path. The oven may be a dual-fuel oven operable to use wood and/or gas fuel.

[40] The oven of the present invention may be portable. The oven of any aspect of the present invention may be portable such that an average human adult male is able to lift and carry the oven independently without further assistance. The oven may have a weight of up to 200kg, such as up to 180kg, or up to 150kg. Suitably, the oven has an internal length from the mouth of the oven to the opposing rear wall of up to 1 ,5m, such as up to 1 ,3m, or up to 1 .1 m. The oven may have a largest internal width of up to 1.5m, such as up to 1.3m or up to 1.1 m. The oven may have a largest internal height of up to 80cm, such as up to 60cm, or up 50cm.

[41] According to a further aspect of the present invention there is provided a method for producing an oven, preferably an oven according to any aspect of the present invention, comprising the steps of: a. optionally attaching an insulation layer to a base; b. attaching a cooking surface to a base or insulation layer, if present, the base comprising a skirt operable to raise the cooking surface from the bottom edge of the oven; c. attaching a liner to a cover, the cover comprising a skirt; d. arranging the cover over the base such that the skirt of the base and the skirt of the cover are abutting, so that the oven comprises a cooking chamber portion, a head portion comprising a mouth and a chimney portion comprising a chimney inlet and an airflow redirection member; e. optionally attaching, suitably fixedly attaching, the skirt of the base and the skirt of the cover together; f. optionally, attaching a lip to the mouth of the oven, suitably attaching a mouth plate to the cover, and optionally to one or more of the skirts, wherein the mouth plate comprises a lip; g. optionally removing a portion of the skirt to form one or more handles. wherein steps a., b., c., f and g may be carried out in any suitable order.

[42] As used herein, reference to “average” means “mean average” unless otherwise provided. All of the features contained herein may be combined with any of the above aspects in any combination.

BRIEF DESCRIPTION OF DRAWINGS

[43] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the following figures.

[44] Figure 1 shows a side sectional view of an oven according to the present invention.

[45] Figure 2 shows a front perspective view of the oven of Figure 1 .

[46] Figure 3 shows a side perspective view of the oven of Figure 1

DESCRIPTION OF EMBODIMENTS

[47] Figures 1 to 3 show a wood-fired oven 102 according to the present invention. Oven 102 is formed of cooking surface 106 enclosed within a housing formed of base 120 and cover 104. Oven 102 has circular based-domed cooking chamber portion 112a (internal diameter 98cm and height 40cm); hemi-cylindrical head portion 112b (internal width 54cm, length 14cm and height 26cm), bulkhead chimney portion 112c (internal width 18cm, length 54cm and height 12cm). Cooking chamber portion 112a contains or is operable to hold the fuel or fuels during cooking, and to receive the food stuffs for cooking. Head portion 112b is a portion of the oven through which the food stuffs are passed via the mouth into the cooking chamber. Head portion 112b spaces the mouth of the oven from the cooking chamber.

[48] Base 120 contains horizontally orientated planar platform 124. Extending downwardly around all of the peripheral edge of platform 124 is skirt 108b. Integrally formed platform 124 and skirt 108b are constructed from fibre-glass. Attached to the upper face of platform 124 with silicone sealant, and co-terminal with platform 124, is insulation board 122. Attached to the upper face of board 122 with fire proof tile adhesive, and co-terminal with board 122, is cooking surface 106. Cooking surface 106 is formed of a single integrally formed refractory ceramic tile that extends through the cooking chamber portion and the head portion. Base 120, fire-proof refractory insulation board 122 and cooking surface 106 collectively form the base section 120 of oven 102.

[49] Cover 104 is formed of domed cooking chamber portion 112a; hemi-cylindrical head portion 112b, chimney portion 112c, skirt 108a, lining 118 and planar mouth plate 114. Head portion 112b is integrally formed with, and projects from, cooking chamber portion 112a. Chimney portion 112c also projects from cooking chamber portion 112a and extends centrally over a part of the upper face of head portion 112b and is also integrally formed with both the cooking chamber portion 112a and head portion 112b. Cooking chamber portion 112a has a bigger largest width than the average width of head portion 1 12b while head portion 112b has a bigger average width than the average width of chimney portion 112c.

[50] Chimney portion 112c comprises airflow redirection member 130 and chimney inlet 126 operable to receive chimney 128. Airflow redirection member 130, which does not permit fluid communication between the oven cavity and the external environment, extends between the top of mouth 116 and chimney inlet 126 such as to space chimney inlet vertically above and laterally backwards (i.e. toward the cooking chamber) from mouth 116. The internal face of airflow redirection member 130 is curved and slopes upwardly from the top of mouth 116 to chimney inlet 126. The curvature of the internal face of the airflow redirection member 130 is such as to substantially represent a continuation of the curvature of the doomed internal face of the cooking chamber at the point where the chimney portion projects from the cooking chamber. The chimney portion is configured such that the flow path of heated air flowing from the cooking chamber to the airflow redirection member 130 is linear, with the highest point of the cooking chamber at substantially the same height as the chimney inlet 216.

[51] Skirt 108a is integrally formed with cooking chamber portion 112a, and head portion 112b and extends downwardly from the bottom of cooking chamber portion 112a and head portion 112b. Cooking chamber portion 112a, head portion 112b, chimney portion 112c and skirt 108a are made of fibre glass and mouth plate 114 is constructed from stainless steel.

[52] Lining 118 extends over the inner face of cooking chamber portion 112a, head portion 112b, and chimney portion 112c. Lining 118 is formed of insulation, binding, and heat resistant layers (not shown). Lining 118 terminates at base 120. The insulation layer of lining 118 extends over and abuts the inner face of the cooking chamber portion 112a, head portion 112b and chimney portion 112c. A binding layer formed of galvanised wire mesh extends over and abuts the inner face of the insulation layer and a heat resistant layer of crushed firebrick cement extends over and around the wire mesh of the binding layer. The heat resistant layer also includes a layer of fine screed extending over the inner face of the layer of firebrick cement. To secure lining 118 to the inner face of cooking chamber portion 112a, head 112b and chimney portion 112c, a plurality of deformable spikes (not shown) are attached to the inner face of cooking chamber portion 112a, head 112b and chimney portion 112c. The spikes extend through the insulation layer and are folded over the mesh to secure the insulation layer to the wire mesh of the binding layer. The presence of the heat resistant layer over and around the mesh further assists in securing the spikes to the mesh. In this manner, a single binding layer enables the attachment of an insulation layer to fibre-glass cover 104 and the attachment of a heat resistant layer to an insulation layer.

[53] The base section of oven 102 is arranged in and fixedly attached to cover 104 such that the outer face of skirt 108b extends parallel to, and abuts, the inner face of skirt 108a and the bottom edge of skirt 108b is co-terminal with the bottom edge of skirt 108a. In this configuration cooking chamber portion 112a and head portion 112b extend upwardly from the peripheral edge of cooking surface 106 around substantially all of the peripheral edge except for the front peripheral edge of cooking surface 106. Skirt 108a extends downwardly from the peripheral edge of cooking surface 106 around substantially all of the peripheral edge except for the front peripheral edge of cooking surface 106. In this configuration, cooking surface 106 is raised from the bottom edge of oven 102 providing an open-bottomed cavity on the underside of oven 102 delineated by the bottom face of platform 124 and by the inner face of skirt 108b. In each of skirts 108a and 108b are two pairs of opposed cut-away portions providing a restricted airflow channel and handles (first pair 10a and 110b, second pair not shown).

[54] Mouth plate 114 is fixedly attached to a side face of oven 102 along a flange (not shown) extending from head 112b and also to the front face of skirt 108b. Mouth plate 114 has hemispherical mouth 116 and is attached to cover 104 and base 120 such that the lower linear edge of mouth 116 is flush with the upper face of cooking surface 106. The arched upper edge of mouth 116 extends upwardly from the lower linear edge of mouth 116. In oven 102 the upper face of cooking surface 106 and the inner faces of liner 118 and mouth plate 114 delineate a cooking chamber portion 112a, a head portion 112b and a chimney portion 112c, which portions are fully enclosed apart from mouth 116 and chimney 128. Mouth 116 may also contain a removable door portion 132, operable to form a close fit attachment with the mouth plate 114. Door portion 132 may comprise a fluid passage operable to allow a small amount of airflow to continue to pass through the mouth 116 when the door portion 132 is in position in the mouth plate 114.

[55] In use, oven 102 is carried from a storage position using handles 110a,b and placed on the intended support surface for use, such as a work top or table. When oven 102 is in the desired position, wood that has been inserted into the cooking chamber of oven 102 via mouth 116 is ignited and further wood added until the desired temperature is reached inside the cooking chamber. The oven may further comprise gas burners, which may be connected to a gas source and used to provide a dual-fuel oven. When the desired temperature is reached any remaining wood and residues thereof can be pushed toward the peripheral edges of cooking surface 106 to allow foodstuffs, such as uncooked pizza, to be inserted via mouth 116 and arranged on cooking surface 106 within the cooking chamber 112a. When cooked, the foodstuff is removed from oven 102 via mouth 116. Once oven 102 has cooled sufficiently it can be returned to a storage position by carrying with handles 110a, b.

[56] As shown by arrows X, the presence of airflow redirection member 130 causes the heated airflow from cooking chamber 112a to be directed toward the cooking surface 106 so as recycle the heated air prior to exit from the oven via the chimney or the mouth, thereby improving the transfer of some of the thermal energy from the heated airflow to the cooking surface. Further, the narrowed chimney portion 112c relative to the head portion 112b may increase the velocity of the airflow from the cooking chamber into the chimney portion, such that more airflow may pass the chimney inlet and contact the airflow redirection member 130 and at a higher velocity.

[57] In use, oven 102 has improved heat retention. Airflow redirection member 130 prevents the heated airflow from rising directly out of the chimney inlet 126 and redirects heated airflow originating from the cooking chamber portion 112a toward the cooking surface 106. Fuel efficiency of the oven 102 is thereby improved, which in turn reduces the time required to being the oven up to temperature.

[58] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[59] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[60] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[61] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.