GB2544394A - Support element for heated outdoor furniture, and method for making such an element - Google Patents

Abstract

A support element for heated outdoor furniture comprising a metal shell 18, a filler material 16 located in the shell and means 15 for heating the filler material or means for warming the shell. The filler material 14 may be concrete and a method is disclosed wherein the shell 18 acts as a mould for the concrete. The concrete may be a synthetic graphite aggregate with the heating means 15 located within it. The concrete may have an electrically conductive portion and employ spaced electrodes. A thermally insulating layer may be provided on a lower surface which may be closed cell polyurethane foam. Concrete layers with different properties may also be provided. Alternatively the heating means may be positioned between thermally insulating filler material and the metal shell. The support element may be a beam for a bench.

Description

Support element for heated outdoor furniture, and method for making such an element

The present invention relates to a support element for heated outdoor furniture, and a method for making such an element. The present invention also extends to outdoor furniture (e.g. a bench) comprising one or more such element. More particularly, the present invention relates to support elements for heated outdoor furniture which comprise concrete. However, in accordance with some further aspects of the invention, advantageous support elements are disclosed which do not necessarily include concrete.

It is desirable to provide heated outdoor furniture, such as benches, so that users can remain outdoors at lower temperatures without getting cold. It will be appreciated that although exemplary embodiments will be described by reference to the case in which the outdoor furniture is a bench, the support element of the invention is also applicable to other types of outdoor furniture, such as seats in general, or indeed to types of furniture other than seats. A support element e g. beam for use in outdoor furniture should be strong enough to be self-supporting, and also to support the load provided thereon in use. It is also desirable for the support element to have an attractive appearance, i.e. without cracking etc., and be suitably durable to withstand the outside environment. Furthermore, the element should be able to efficiently distribute heat e.g. to a support surface thereof, as required in use.

Previous heated outdoor furniture products include benches formed from cast concrete beams that are bolted to a metal frame. The benches work in a similar way to electrical underfloor heating by utilising a cable embedded in the concrete to generate heat in the beams. Such beams are manufactured by casting concrete and the internal heating structures in a mould that the beam is removed from once the concrete has sufficiently cured prior to being incorporated into the bench. The mould can be made from various materials, such as polyurethane, silicone, glass reinforced plastic (fibreglass) or rubber.

The Applicant has recognised that there remains scope for improvement in support elements e.g. beams for outdoor furniture, and in methods for making such elements.

In accordance with a first aspect of the present invention there is provided a support element for heated outdoor furniture, the support element comprising: a concrete layer and means for heating the concrete layer when energised in use; wherein the support element further comprises a metal shell, the concrete layer being located in the metal shell.

In accordance with the invention therefore, in addition to a concrete layer, and means for heating the concrete layer, the support element comprises a metal shell. The metal shell at least partially encases the concrete layer. The presence of the metal shell provides strength properties to the support element, including compressive and tensile strength. In contrast to prior art support elements which do not include a metal shell, the demands placed on the strength properties of the concrete itself are reduced, as the concrete is no longer required to provide all of the structural properties e.g. strength of the element. This opens up the possibility of using a wider range of types of concrete, including weaker concretes. The properties of the concrete may be tailored to impart other properties to the support element. For example, the concrete may be selected to have improved properties such as reduced density, to form a lighter support element, and/or increased or decreased thermal and/or electrical conductivity as required in various embodiments, as described in more detail below. Furthermore, multiple layers of concrete imparting different properties may be used. In addition to providing strength to the element, the metal shell may help to prevent water ingress, and may provide a more uniform outer surface to the element that is not prone to thermal cracking in the same way as a concrete surface would be. The metal shell may also provide a surface which may be more readily decorated as required e g. to customise the appearance of furniture incorporating the support element, and/or may itself provide a more attractive outer surface.

In particularly preferred embodiments the concrete layer has been cast in the metal shell, the metal shell having acted as a mould for the concrete layer during casting thereof. Thus the metal shell provides a mould for the concrete layer which becomes an integral part of the support element.

It is believed that such embodiments are advantageous in their own right. From a further aspect of the invention there is provided a support element for heated outdoor furniture, the support element comprising: a concrete layer and means for heating the concrete layer when energised in use; wherein the support element further comprises a metal shell, wherein the concrete layer has been cast in the metal shell, the metal shell having acted as a mould for the concrete layer during casting thereof.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith.

In accordance with these further aspects and embodiments of the invention, the concrete layer of the support element is moulded in the metal shell, which then becomes an integral part of the support element. The metal shell may be the only mould used in casting the concrete layer. The use of a metal mould that remains part of the final product provides a number of advantages in contrast to prior art techniques of the type described above, in which concrete is cast in a mould, and then removed therefrom to provide a support element e.g. beam for outdoor furniture. For example, the initial curing process of a concrete layer for use in a beam of outdoor furniture may take in the region of 12 hours. Conventional moulds are typically expensive and difficult to make, and may have a limited lifetime. It is customary to reuse the moulds, and given the curing time for each concrete layer, it may only be possible to produce a beam approximately every 1-2 working days. In contrast, in accordance with these further aspects and embodiments of the invention, the concrete layer is not removed from the metal mould. This allows for improved production rates, as the concrete layer can be left to cure whilst another metal shell is filled to provide another support element. In other words, it is not necessary to wait to reuse a mould. This may allow the cost of producing each support element to be significantly reduced. A mould in the form of a metal shell may be cheaper and easier to produce than prior art moulds. As the shell then becomes an integral part of the support element, the shell may provide the benefits described above that are associated with the inclusion of a metal shell. The metal shell forms part of a final product including the support element.

The present invention extends to a method of making a support element for heated outdoor furniture in accordance with the invention in any of its aspects or embodiments. The method involves casting the concrete layer in the metal shell.

The method may comprise providing the metal shell, introducing a concrete mix into the metal shell, and allowing the concrete to set to form a concrete layer in the metal shell. The method may further comprise the step of providing the means for heating the concrete layer when energised.

In accordance with a further aspect of the invention there is provided a method of forming a support element for heated outdoor furniture, the method comprising: providing a metal shell shaped to act as a mould; providing a concrete mix in the metal shell; and allowing the concrete to set to form a concrete layer in the metal shell; wherein the method further comprises providing means for heating the concrete layer when energised.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith.

It will be appreciated that the method of this aspect of the invention may provide a support element in accordance with any of the aspects or embodiments of the invention described herein. Similarly the support element in accordance with any of the aspects or embodiments of the invention may be produced using a method according to any of the embodiments described herein, to the extent that it is not incompatible therewith.

The step of providing the concrete mix in the metal shell preferably comprises introducing the concrete mix into the metal shell. The step preferably comprises pouring the concrete mix into the shell. Preferably the concrete mix is introduced into the bottom of the shell. The ingredients of the concrete mix may be mixed in a mixer before being introduced to the shell. The method does not include a step of removing the concrete layer from the metal shell once set. The metal shell forms part of the support element that is, or is to be, incorporated in heated outdoor furniture. In these aspects and embodiments of the invention, the heating means that is provided is for heating the set concrete layer when energised i.e. the concrete layer in the support element that is produced. The metal shell acts as a mould for the liquid concrete mix. The metal shell defines a hollow cavity for receiving the liquid concrete mix. The shell should be sufficiently fluid tight to retain the liquid concrete that is introduced thereto.

In accordance with the invention in any of its aspects or embodiments, the concrete layer is preferably present at least at the bottom of the metal shell. The concrete layer may extend any distance up the sides of the metal shell, depending what other layers, concrete or otherwise, may be present in the shell. In some embodiments the concrete layer is located only at the bottom of the metal shell. The layer may cover the bottom of the shell. The bottom of the metal shell may be defined by the surface of the shell that provides the bottom of the mould in preferred embodiments in which the concrete layer is cast in the shell. These embodiments are preferred in that the heated concrete layer may be located adjacent the bottom of the metal shell to enable heat to be efficiently transferred to the shell. In preferred embodiments the concrete layer directly contacts the interior of the metal shell. It will be appreciated that the interior of the metal shell may have a surface coating e.g. of an electrically insulating material as discussed below. Preferably no structural layer is located between the concrete layer and the interior surface of a bottom of the metal shell. Of course, other embodiments may be envisaged in which the heated concrete layer is not located adjacent the bottom of the metal shell. In such embodiments heat may then be transmitted to a user or object from an exposed surface of the concrete layer, or via another suitably thermally conductive component of the support element e g. a cover.

In accordance with the invention in any of its aspects or embodiments, the concrete layer may comprise any type of concrete known in the art, unless otherwise stated. This applies to any concrete layer present. The term "concrete" as used herein has its usual meaning in the art. The concrete may comprise a mixture of aggregate material, cement and water. Aggregate material as used herein refers to any inert filler material. The aggregate material may include a mixture of different materials. The materials may be present in different proportions by weight. Aggregate material may include synthetic or natural material(s). The term "aggregate material" as used herein encompasses particulate materials and fibers, although is not limited thereto. Any type of solid material may provide an aggregate material. Particulate aggregate materials may be of a broad range of sizes and forms, ranging from very fine to coarse. For example, an aggregate material may be in the form of a powder. Aggregate materials include sand, gravel and/or crashed stone, as well as more specific materials which may be added to impart desired properties to the concrete e.g. glass fibre, metal filings, plastic strands, carbon based particles or fibers etc. For example, glass fibre or plastic strands may help impart strength, while metal powder or filings may help impart thermal and/or electrical conductivity. In some preferred embodiments, as described below, specific aggregate materials are used to impart desired properties to a concrete layer.

The properties of the concrete may be tailored by selecting an appropriate composition for the concrete mix. The properties of the concrete may be tailored by the appropriate selection of the aggregate material, the inclusion of appropriately selected non-aggregate additive(s) and/or by selection of an appropriate ratio for the components of the concrete. For example, certain non-aggregate additives can affect the viscosity of the concrete, which can allow for a low ratio of water to cement in the mix whilst still maintaining a mix with a low viscosity to aid in pouring during the manufacturing stage. Exemplary additives for modifying viscosity in this way include polycarboxylate ether, or types of sulphonate, such as naphthalene or melamine sulphonate. Such additives may be added to the concrete mix in the form of liquid additives. A low water to cement ratio is advantageous as it helps increase the overall strength of the cured concrete, and can also help to reduce air bubbles within the concrete, therefore increasing strength and reducing shrinkage of the concrete when curing.

The above features apply equally to any additional concrete layer e.g. a second concrete layer, where provided.

The term "concrete mix" used herein (in relation to any given concrete layer), refers to a composition which may set to form a solid concrete. The unset concrete or concrete mix may also be referred to as "liquid concrete". In any of the embodiments in which the or a concrete layer is said to include a particular material, the method will comprise incorporating such a material in the concrete mix for the layer.

As mentioned above, due to the presence of the metal shell in accordance with the invention, the strength properties demanded of the (heated) concrete layer are reduced. The concrete is no longer required to solely support all components of the support element e.g. heating means etc. Previously, the choice of concrete material was limited by this constraint, and as the concrete material would also need to be able to withstand wear and tear in use e.g. in a public outdoor environment. Typically, in order to provide the necessary strength properties, high density concrete material would be used, which would result in a relatively high weight element. High density concrete may be more susceptible to suffering from thermal stresses, with the result that micro stress fractures may appear on the surface of the layer In prior art arrangements in which the surface of the concrete layer provides an external surface of the resulting support element e.g. beam, this may impact on the aesthetic look and finish of the element.

The use of the metal shell in accordance with the invention opens up the possibility of using a wider range of concrete materials than in prior art arrangements which do not include such a metal shell, which concrete materials may be selected to impart the support element with desired properties useful in the context of heated outdoor furniture. Furthermore, in accordance with some further aspects of the invention, it has been recognised that the use of a metal shell opens up yet more possibilities for the construction of a support element for heated outdoor furniture, which are not necessarily limited to the use of a concrete layer. Such further aspects and embodiments of the invention are described below. For the avoidance of doubt, any of the features described herein by reference to a support element including a concrete layer, or which are generally described, are equally applicable to such further aspects or embodiments of the invention which do not include a concrete layer, unless they are mutually exclusive, or the context demands otherwise.

Returning to those aspects and embodiments of the invention including a concrete layer, in some embodiments the concrete layer comprises a carbon based aggregate material, and preferably a graphite aggregate material. Although the graphite may be a naturally occurring form of graphite, most preferably the graphite is a synthetic graphite. Similarly, any other carbon based material may be naturally occurring or, more preferably synthetic. The inclusion of a carbon based e.g. graphite aggregate material in the concrete layer may result in a layer which is of a lower density and weight than “standard” concrete. A concrete having a density of less than 2000 kg/m3 is defined as being low density in the industry. A concrete layer in accordance with the invention comprising a carbon based aggregate material may have a density within this range. In general, whether or not it comprises a carbon based e g. graphite aggregate material, the concrete layer preferably has a density of less than 2000 kg/m3. It will be understood that such densities may be achieved e g. using other appropriately selected aggregate material(s). While such a layer may be weaker than "normal" concrete, due to the presence of the metal shell, this need not be a problem in accordance with the invention. The use of the lower density concrete layer enables a lighter support element to be obtained. This is advantageous for a support element in the context of outdoor furniture, providing greater ease of manufacture, assembly, and shipping of the element and/or furniture incorporating the element, and greater ease of use, enabling a user to more easily move the resulting outdoor furniture. It has been found that the graphite or other carbon based aggregate material, and hence a concrete layer comprising such material, also has good thermal and electrical conductivity. The thermal conductivity allows the heat from the heating means to diffuse through the concrete layer more quickly and evenly than would be possible using "standard" concrete of a lower thermal conductivity. This may provide a quicker warm-up time for the support element. By producing a more even heat distribution throughout the concrete layer, thermal expansion stress on the concrete may be reduced, in turn reducing rates of thermal stress fracturing, which may prolong the life of the support element. It will be appreciated that the carbon based e.g. graphite aggregate material should be included in a suitable quantity to help achieve the desired properties of the layer, and other types of aggregate material will typically be present in the concrete i.e. more conventional aggregate materials.

It has also been found that the electrical conductivity properties of a concrete layer including a carbon based e.g. graphite aggregate material, enable a portion of the concrete layer to act as a resistive heat element when a current is applied thereto in use, so as to provide a way of heating the concrete layer directly, without needing to incorporate a separate heating element. Such embodiments are described in more detail below. The concrete layer may comprise any of the aggregate materials below described in relation to those embodiments. For example, the concrete layer may comprise Marconite® aggregate material. However, it will be appreciated that a concrete layer including the advantageous carbon based e.g. graphite aggregate material, such as Marconite®, need not be used with such heating means, and embodiments using such aggregate materials may alternatively comprise a separate heating element.

The method of forming the support element may comprise using a concrete mix including any of the materials in the embodiments discussed above to obtain a concrete layer comprising the material(s).

In accordance with the invention in its various aspects and embodiments including a concrete layer, the support element comprises means for heating the concrete layer when energised. The heating means enables the concrete layer of the support element to be heated when the element is incorporated in outdoor furniture. In preferred embodiments the concrete layer comprises the heating means. The heating means may be disposed in any suitable manner with respect to the concrete layer to result in heating of the concrete layer. For example the heating means may be located in, on and/or around the concrete layer. In preferred embodiments the heating means is located at least partially, and preferably entirely within the concrete layer. The heating means may be at least partially embedded in the concrete layer.

The method may comprise locating the heating means with respect to the concrete layer in any of these manners. The method may comprise locating the heating means so as to be at least partially, and preferably entirely within the concrete that provides the concrete layer before the concrete sets. This may result in the heating means being at least partially embedded in the concrete layer. Preferably the heating means is located in the metal shell before the concrete mix for forming the concrete layer is introduced thereto.

The means for heating the concrete layer may be any means that can heat the concrete layer when energised, for example by applying an electric current to the heating means. Preferably the heating means is electrical heating means. The heating means is then energised through connection to an electrical power supply in use. The means may heat the concrete layer directly, for example by passing an electrical current through at least a portion of an electrically conductive concrete layer. Alternatively, the means may heat the concrete indirectly, for example, comprising one or more heating element, which may be embedded in the concrete, which is heated, heat then being provided to the concrete layer through thermal conduction. A combination of such techniques may be used. In either embodiment the heating means may be arranged to generate heat in substantially the entire width and/or length of the concrete layer, or a portion thereof.

In accordance with some embodiments of the invention, the means for heating the concrete layer comprises at least one heating element associated with the concrete layer for providing heat to the concrete layer. The or each heating element may be of any suitable form. The heating element may be any electrically resistive element. The or each heating element may be a metal element. It will be appreciated that in these embodiments, the or each heating element is provided by a separate component or components added to the concrete layer, in contrast to the alternative embodiments in which an electrically conductive portion of the concrete layer effectively acts as a heating element. The or each heating element is not formed from concrete.

The at least one heating element may be embedded in the concrete layer. The or each heating element may be in the form of a cable. A heating element e.g. cable may be disposed in any suitable manner. For example, in some embodiments a heating element is provided in a serpentine configuration. The support element may further comprise means for connecting the at least one heating element to a power supply for supplying electrical energy to the or each heating element in use e.g. one or more set of terminals. In these embodiments of the invention, the method may comprise locating the at least one heating element in the metal shell and in contact with the concrete mix before the concrete mix providing the concrete layer sets, so as to embed the at least one heating element in the concrete layer. The at least one heating element is preferably located in the metal shell before the concrete mix is introduced thereto.

In accordance with some embodiments of the invention, the heating means comprises one or more heating panels. The heating means may comprise a single heating panel, or a plurality thereof. The or each heating panel may conform to a surface to be heated. The heating panel includes a major surface which may be located in face to face relationship with a surface to be heated. The or each heating panel is an electrical heating panel. The or each panel is then arranged to provide heat when electrically energised in use. The support element may further comprise means for connecting the or each heating panel to a power supply for supplying electrical energy to the heating panel in use e.g. one or more set of terminals and/or one or more connectors.

The following features described in relation to a heating panel are applicable to at least some, or the or each such panel that is present. Where a plurality of heating panels are provided, each heating panel may be of identical construction. It will be appreciated that, unless otherwise stated, one or more additional heating panels may be present, in addition to one or more such panels, whose construction and/or location is defined, or such one or more heating panels may be the only such panels present.

Preferably the heating panel is a flexible heating panel. Such a heating panel may readily be used to provide heat to any shaped surface, and may conform closely to the surface to transmit heat thereto. However, it is envisaged that a non-flexible heating panel may be used that is shaped to conform to the surface to be heated. For example, a flat heating panel may be used where the surface is a flat surface. Other shaped panel heaters may be envisaged that have a shape corresponding to the surface to be heated e.g. including a curved portion or portions. A heating panel comprises a heating element. Where the heating panel is a flexible heating panel, the heating element is a flexible heating element. The heating element may be of any suitable construction. The heating element may, for example, be a wire wound or etched foil heating element. Such heating elements are particularly applicable to flexible heating elements. The heating element may be a printed element. The heating element may be a thick film heating element.

The heating panel (and, in embodiments, the heating element) may be substantially planar. The heating panel may be of a laminate construction. The heating panel may comprise a heating element layer disposed between outer substrate layers. In particularly preferred embodiments in which the heating panel is a flexible heating panel, the outer substrate layers may be silicone rubber layers. Additional layers may be present e.g. an adhesive layer for attaching the panel to a substrate e.g. the concrete layer. The heating panel may be of a thin construction. The heating panel may be sheet-like. However, other forms may be envisaged. Preferably the heating panel has a thickness of less than 5 mm. In some preferred embodiments, the heating panel is a flexible heating panel in the form of a heat mat, such as a silicone rubber heat mat. However, it will be appreciated that other types of flexible heating panel may be suitable.

It will be appreciated that a heating panel may be significantly thinner than a conventional heating cable. It has been found that the use of a heating panel provides greater flexibility in choosing the thickness of the concrete layer, in contrast to embodiments in which a conventional heating element e.g. cable is embedded in the concrete layer. In embodiments in which a conventional heating element is embedded in the concrete layer, the concrete layer is ideally of a thickness to surround the heating element, and the thickness of the concrete layer is thus constrained by the diameter of the heating element. In contrast, a heating panel is relatively thin, and may readily be attached to a surface of the concrete layer, rather than being embedded therein. The use of a heating panel may therefore allow for a significant reduction in the thickness of the concrete layer. The ability to reduce the thickness of the concrete layer is advantageous in certain contexts in that this may reduce the weight of the resulting support element. The time required for the support element to heat up when energised may also be reduced. In embodiments in which the heating means comprises one or more heating panel, preferably the one or more heating panels provide the only heating means for the support element i.e. no conventional heating cable is present.

The or each heating panel may be disposed in any suitable manner with respect to the concrete layer for supplying heat thereto. Heating panels may be customised to a wide range of shapes and sizes. It will be appreciated that the aspect ratio of the heating panel may be chosen as desired to provide a given surface area coverage, depending upon the shape of the concrete layer to be heated. One or more such heating panel may therefore be used to provide a suitable surface area coverage for a desired application. Each heating panel is arranged to provide heat to at least a portion, and, in embodiments, only a portion, of the surface to be heated. The or each heating panel is preferably associated with e g. located adjacent a surface of the concrete layer. The or each heating panel is then arranged so as to be in thermal contact with the surface to supply heat thereto. The thermal contact is preferably a direct thermal contact. The or each heating panel may be attached e.g. adhesively to the concrete layer. Preferably the or each heating panel is directly attached to the concrete layer (e.g. via an adhesive layer). In some preferred embodiments, as described below, the support element comprises a first heated surface intended to face a user or object in use to provide support thereto, and an opposite second surface intended to face away from the user or object supported by the support element in use, and the or each heating panel is located adjacent the concrete layer on a side of the concrete layer closer to a second surface of the support element.

Multiple heating panels may be spaced from one another.

It will be appreciated that a flexible heating panel as referred to herein in any of the aspects or embodiments of the invention is flexible to enable it to conform to a surface to be heated when applied thereto. The heating panel is inherently flexible. However, in the resulting support element, the flexible heating panel typically will be constrained by the rigidity of the component(s) to which it is applied, and will not be free to flex.

In embodiments of the invention using a heating panel, the method may comprise the step of locating one or more heating panel on a surface of the concrete layer formed in the metal shell. The method may comprise attaching the or each heating panel to the surface of the concrete layer, preferably using adhesive. In these embodiments, the heating panel(s) are associated with the set concrete layer. The concrete layer may have a first surface closer to the bottom of the shell, and an opposite second surface, the or each heating panel being attached to the second surface of the concrete layer.

In accordance with yet other embodiments of the invention, at least some of the concrete layer is electrically conductive, and the means for heating the concrete layer comprises means for passing an electrical current through one or more electrically conductive portion of the concrete layer in use to generate heat in the layer. The or each portion of the concrete layer thus acts as a resistive heating element. Preferably the or each portion through which electrical current is passed extends substantially the entire width and/or length of the concrete layer. In some embodiments an electrical current may be passed through a single portion of the concrete layer extending substantially the entire width and/or length of the concrete layer. The heating means may be arranged to pass an electrical current through substantially the entire concrete layer.

The heating means may comprise one or more set of at least two spaced apart electrodes, the or each set of electrodes being arranged to pass an electrical current through an electrically conductive portion of the concrete layer in use. It is envisaged that the heating means may be arranged to pass an electrical current through one or more discrete electrically conductive portions of the concrete layer in use to generate heat.

It is believed that the use of such arrangements to heat a concrete layer of a support element used in outdoor furniture are advantageous in their own right, whether or not the support element includes a metal shell.

From a further aspect of the present invention there is provided heated outdoor furniture comprising at least one support element, the support element comprising: a layer of concrete and means for heating the concrete when energised in use; wherein at least some of the concrete layer is electrically conductive, and the means for heating the concrete layer comprises means for passing an electrical current through one or more electrically conductive portion of the concrete layer in use to generate heat in the layer.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith. The outdoor furniture may be in accordance with any of the embodiments described below. The properties of the concrete layer may be in accordance with any of the embodiments of the concrete layer described above or below in relation to the earlier aspects and embodiments of the invention including a metal shell, and in which such a layer includes one or more electrically conductive portion that forms part of a heating means. The heating means may be of the construction described in relation to any of those embodiments above or below. The support element may further comprise a thermally insulating layer as described in any of the embodiments below, whether or concrete or not. The support element may further comprise a second concrete layer, which may be of the construction of any of the embodiments described below.

In accordance with the invention in any of its aspects or embodiments in which the heating means comprises means for passing an electrical current through one or more electrically conductive portion of a concrete layer, a plurality of sets of spaced electrodes may be provided, each set of electrodes being arranged to pass an electrical current to through an electrically conductive portion of the concrete layer in use. In other embodiments a single set of spaced electrodes may be provided for passing a current through an electrically conductive portion of the concrete layer. Preferably a set of electrodes is provided that includes electrodes located at two opposing edges of the concrete layer e g. at laterally or longitudinally opposed edges thereof. The electrodes at the opposing edges may extend along the edges thereof, for up to the full length or width of the layer. At least one such set of electrodes may be provided. The or each set of electrodes is preferably a pair of electrodes. A single such set of electrodes may be provided, or different pairs of electrodes may be located at different positions along the opposed edges. Of course, rather than being a pair of spaced electrodes, the or each set of electrodes may include a different number of electrodes, e g. three electrodes as discussed below. In preferred embodiments at least one set of electrodes is provided which includes electrodes located along opposed longitudinally extending edges of the concrete layer. Locating the electrodes at two opposing edges of the concrete layer may maximise the volume of the concrete layer through which electric current flows in use. This may maximise the volume of concrete that is directly heated, increasing the uniformity of heating throughout the support element.

In accordance with any of the embodiments of the invention in which the heating means comprises one or more set of two or more spaced electrodes, the or each set of two or more electrodes may be a pair of spaced apart electrodes i.e. including only two electrodes. In other embodiments, a set of electrodes may include three electrodes. In such embodiments, the set of electrodes comprises a single charged electrode between two oppositely charged or neutral electrodes. The oppositely charged or neutral electrodes may be located at two opposing edges of the concrete layer, with the single charged electrode located therebetween. Preferably, the single charged electrode is located equidistant from both of the oppositely charged or neutral electrodes to ensure uniform heating of the concrete. While a set of electrodes may include only two or three electrodes, sets of electrodes may be envisaged having more than three electrodes.

Whatever the construction of the electrodes, the support element may further comprise means for connecting the or each set of electrodes to a power supply for supplying electrical energy to the or each electrode in use e.g. one or more set of terminals. The or each set of electrodes may be embedded in the concrete layer. Where multiple sets of electrodes are provided, each may be a pair of electrodes, or a set of three electrodes, or a combination of one or more pair, and one or more set of three electrodes may be used.

In these embodiments of the invention, the method may comprise locating the at least one set of electrodes in the metal shell and in contact with the concrete before the concrete providing the concrete layer sets, so as to embed the at least one set of electrodes in the concrete layer.

In these embodiments, when the heating means is energised, a current is applied thereto, which flows through the or each electrically conductive portion of the concrete to directly heat the concrete layer. This avoids the need for a separate electrical heating element, which may decrease manufacturing costs, and allow a lighter weight support element to be obtained. Further, it has been found that in these embodiments, the electrically conductive concrete between the electrodes may tend to be more uniformly heated, which may prevent or reduce thermal differentiation (or cold spots) within the electrically conductive concrete. This may reduce thermal stress on the concrete layer, and in turn may more evenly heat the metal shell.

It will be appreciated that at least the or each portion of the concrete layer to through which an electrical current is applied is electrically conductive in these embodiments. At least some, and preferably the entirety of the concrete layer is electrically conductive. The arrangement of the heating means may be chosen appropriately to generate heat in a selected portion or portions of the electrically conductive concrete layer. Thus, at least some, and preferably all of the concrete layer is electrically conductive, and the heating means is arranged to pass an electrical current through one or more selected electrically conductive portions thereof to generate heat in the layer. The heating means may be arranged to pass an electrical current through substantially the entire concrete layer where the entire layer is electrically conductive.

Providing an electrically conductive concrete layer, or portion thereof, may be achieved by using a suitable electrically conductive concrete material. It will be appreciated that references to an electrically conductive concrete layer or portion thereof herein refer to the concrete layer having inherent electrical conduction properties as a result of the ingredients of the concrete mix used to provide the concrete layer. The electrically conductive concrete layer or portion thereof comprises electrically conductive material e g. electrically conductive aggregate material, such as particles and/or fibers to render the concrete electrically conductive. Examples of such materials are known e g. in the context of providing heated pathways or earth electrodes for lightning conductors. In some preferred embodiments the electrically conductive concrete layer or portion thereof comprises a carbon based aggregate material. Preferably the electrically conductive concrete layer or portion thereof comprises a graphite aggregate material, and most preferably a synthetic graphite aggregate material. Graphite or other carbon based aggregate material may impart the layer with suitable electrical conductivity properties. For example, it has been found that the Marconite® aggregate material may be suitable. It has been found that suitable electrically conductive concrete materials may also have good thermal conductivity properties, as described above. For example, the preferred carbon based e.g. graphite aggregate materials may additionally impart such thermal conductivity properties. This may result in more uniform heating of the concrete layer, and a reduction in thermal stress on the layer. A concrete layer comprising the carbon based e.g. graphite aggregate materials may also be of lower density than a "standard" concrete layer, resulting in a lighter weight support element. Preferably the concrete layer is a layer of electrically conductive concrete comprising the carbon based e.g. graphite aggregate material.

It will be appreciated that the electrical resistivity of a concrete layer or portion thereof including an electrically conductive aggregate material may be tailored as desired by selecting an appropriate ratio of the aggregate material relative to the other ingredients of the concrete of the layer e.g. relative to the amount of the other aggregate materials and/or cement in order to provide a desired heating effect when an electrical current is applied thereto. For example, a ratio of cement, the aggregate material, and other "standard" i.e. non electrically conductive aggregate material may be balanced to achieve a desired electrical resistance. In some preferred embodiments the concrete layer or portion thereof comprises sand, cement and a graphite aggregate material. Other electrically conductive e.g. aggregate material may be used in addition to a graphite or other carbon based aggregate material to try to achieve a desired electrical conductivity in the concrete layer or portion thereof. In some embodiments the concrete of the concrete layer may further comprise iron and/or steel material. Such material may be in the form of e.g. fibers, filings or powder. Of course, it is envisaged that other electrically conductive aggregate materials, such as iron and/or steel material in various forms, may be used without a carbon based e.g. graphite aggregate material to impart electrical conductivity properties. The electrical conductivity desired to be achieved is dependent on a variety of factors, such as the potential difference expected across the terminals, and the size and orientation of the terminals.

The method of forming the support element may comprise using a concrete mix including any of the materials discussed above to obtain a concrete layer comprising the material(s).

In embodiments in which an electric current is applied to one or more portions of the concrete layer to generate heat, it will be appreciated that an electrically insulating material may need to be provided between the or each portion of the concrete layer and a surface of the metal shell in order to prevent the or each electrically conductive portion of the concrete layer and the shell from coming into electric contact. This ensures that the metal shell does not become electrically live, and that there is no risk of electric shock to a user. The metal shell should also be earthed in any suitable manner in outdoor furniture including the support element. Preferably the metal shell is earthed independently of the electrical insulating material i.e. using additional earthing means. This may be achieved e.g. via an electrical earth in a control box. This acts as protection if the electrically insulating material were to fail and the metal shell were to become electrically live, as the metal shell would then e.g. trip a suitable safety power cut off device, such as a fuse, residual current device (RCD), or circuit breaker, via the earth connection, rendering outdoor furniture incorporating the element safe. It will be appreciated that suitable arrangements may be provided as desired to adhere to relevant safety regulations. Similar arrangements may also be used e.g. if an electrically conductive portion of the concrete layer would alternatively or additionally otherwise be in electrical contact with another electrically conductive component of the support element e.g. a cover.

In embodiments, the support element therefore further comprises an electrically insulating material between the metal shell and the concrete layer. This could be another concrete layer in the case that the surface of the metal shell is not used to transmit heat to a user or object. However, preferably the metal shell is used to transmit heat to the user or object. The electrically insulating material is preferably selected so as to minimise its impact on transmission of heat to the metal shell. In some embodiments the electrically insulating material is a surface coating provided on a concrete facing (i.e. inner) surface of the metal shell. The coating may be, for example, a coating of an electrically insulating paint e g. powder coat paint or an epoxy layer. Such layers may be relatively thin, minimising impact on thermal transmission The method may further comprise providing an interior surface of the metal shell with an electrically insulating surface coating before introducing the concrete thereto. The electrically insulating surface coating may be of any of the types described above.

In accordance with the invention in any of its aspects or embodiments, regardless of the form of the heating means, and including in the further aspects of the invention described below, which do not necessarily include a concrete layer, the support element is arranged such that heat provided by the heating means (e,g, to the concrete layer in use) may be transmitted to a user of outdoor furniture including the support element in use, and/or to an object supported by such furniture. While in preferred embodiments the outdoor furniture is in the form of a seat or similar, in which the or each support element of the invention supports a user, it will be appreciated that the support elements may be used in other types of furniture, and may be used to support a wide range of objects. For example, the support element(s) may be used in a table to provide a heated surface thereof. The support element therefore comprises a heated support surface. Any reference to a user facing or supporting surface herein may be interchangeable with an object facing or supporting surface. Preferably, however, the support element is used to provide support to a user of outdoor furniture, and is arranged to transmit heat to a user of the furniture.

The support element may comprise a first surface intended to face a user or object in use to provide support thereto. Heat may then be transmitted to a user or object via the first surface in use. The first surface is thus a heated surface. The support element may be arranged such that one or more portions, or the entire first surface thereof is heated. The first surface of the support element is preferably defined by the metal shell e.g. by an exterior of a first surface of the metal shell. However, it is envisaged that other arrangements might be used e.g. where heat is to be transmitted to a user or object via a backplate of the support element or other surface not defined by the metal shell. The support element may comprise an opposite second surface intended to face away from a user or object supported by the support element in use. However, it will be appreciated that there is no constraint placed on the shape of the support element, and more complex shapes may be envisaged e.g. which do not necessarily include opposed first and second surfaces. In embodiments in which the support element comprises an opposite second surface intended to face away from a user or object supported by the support element in use, the second surface does not need to be heated. Indeed, it is desirable that the second surface is not heated, so as to minimise loss of heat through the second surface. The first surface of the support element may be referred to as a front surface thereof, and the second surface a reverse surface thereof. The first and second surfaces of the support element may be connected by the sides of the support element. The sides may be defined by one or more, and preferably a plurality of sidewalls. The first and second surfaces of the support element, and, where applicable, the sides thereof, provide external surfaces of the support element in use. Other surfaces of the support element may or may not be heated e.g. surfaces defining sides thereof. The support element may include only one heated surface. In accordance with the further aspects and embodiments of the invention relating to outdoor furniture incorporating one or more of the support elements of the invention, the or each such element is oriented such that heat may be transmitted to a user or object supported by the support element in the outdoor furniture in use. Thus, the heated surface e.g. first surface of the or each element is a user or object facing surface thereof.

In those aspects and embodiments of the invention in which the support element includes a concrete layer, where the support element comprises first and second surfaces as above, the support element may comprise a thermally insulating layer, located on a side of the heating means toward the second surface of the support element.

The thermally insulating layer is preferably located within the metal shell. A surface of the thermally insulating layer may, at least in part, define the second surface of the support element. However, in other embodiments the insulating layer is located within the support element between the heating means and the second surface of the support element. The thermally insulating layer may be located on a side of the concrete layer toward the second surface of the support element. The thermally insulating layer may be located adjacent the concrete layer. Thus, the concrete layer may be present on only one side of the insulating layer. In other embodiments the thermally insulating layer may be located within the concrete layer. The second surface of the support may then be defined at least in part e g. by the concrete layer, or a cover for the metal shell. Of course, other embodiments might be envisaged in which the thermally insulating layer could be located between the (first surface) of the shell and the concrete layer, e g. in the event that heat was to be transmitted to a user or object other than through the shell.

In some embodiments, the heating means may comprise one or more heating panel sandwiched between the concrete layer and the thermally insulating layer. The or each heating panel may be adhesively attached to the surface of the concrete layer. In these embodiments in which one or more heating panel is sandwiched between the concrete and thermally insulating layers, the thermally insulating layer is preferably an expanded foam layer that has expanded in the shell, as described below. The expandable foam may expand to fill the shell, regardless of the thickness of the concrete layer, being advantageous in the context of the thinner concrete layers which are possible in these embodiments.

Regardless of the form of the heating means, in embodiments including a thermally insulating layer, the thermally insulating layer may be of any suitable form. A thermally insulating layer may be provided using any type or types of thermally insulating material, which may be continuous or discontinuous. The thermally insulating layer may be a rigid layer. This may be particularly appropriate where the layer defines a second surface of the support element. The thermally insulating layer may be in the form of a thermally insulating board.

In some embodiments of the invention, described below, the thermally insulating layer may be provided by a further concrete layer. In other embodiments the thermally insulating layer is a non-concrete layer.

The thermally insulating layer may comprise or consist of a foam material. For example, a polyurethane foam material may be used. Such a foam material may provide a rigid insulating layer. Whether or not it is a polyurethane foam material, the foam material may be a closed cell foam material. The material may be an expanded, rigid polyurethane foam material. A thermally insulating board may comprise an extruded polystyrene foam core coated with a cement mortar to form a flat rigid sheet. An example of such a board is a Marmox® board. Of course, other suitable thermally insulating materials may be used. Desirably the insulating material may be lightweight i.e. low density in order to minimise weight of the support element.

In preferred embodiments the thermally insulating layer extends over an entire surface of the concrete layer (i.e. the surface facing the second surface of the support element) and/or the thermally insulating layer is continuous over its surface. This may help to maximise the thermally insulative effect.

The thermally insulating layer may be embedded in the concrete layer. In these embodiments the insulating layer may extend over only a portion of the area of the concrete layer to enable the concrete to surround the insulating layer e.g. to flow around and cover the insulating layer. Alternatively or additionally the insulating layer may comprise one or more openings therethrough through which concrete has flowed to create reinforcing concrete pillars extending between the sides of the insulating layer. However, as a result of the use of the metal shell in accordance with the invention, such reinforcing pillars may not be necessary. Furthermore, it is less important to reduce the size of the insulating layer by having it extend over only a portion of the area of the concrete layer than in prior art arrangements, in which this was done to try to maintain strength of the element e g. beam.

In some embodiments the thermally insulating layer is a foam layer that has set in the shell, and most preferably an expanded foam layer that has expanded and set in the shell. The liquid foam material may then be introduced into the shell once the concrete layer has set.

Of course, whatever its construction, thermally insulating material may additionally or alternatively be provided around the sides of the support element, or any portion thereof, to reduce heat loss therethrough. In other embodiments, at least a portion of the sides of the support element may not be thermally insulated so as to provide heated sides thereto.

In embodiments in which an electric current is passed through at least a portion of the concrete layer to generate heat therein, the thermally insulating layer located between the heating means and the second surface of the support element may additionally provide electrical insulation properties where it is an electrically insulating material.

The method may comprise locating a thermally insulating layer within the metal shell in any of the manners described. The method may comprise locating thermally insulating material on the concrete layer after setting of the concrete layer to provide the thermally insulating layer, or embedding the thermally insulating layer in the concrete layer on a side of the heating means away from the interior surface of the metal shell i.e. by locating the thermally insulating layer in the shell before the concrete sets. Where the thermally insulating layer is a foam thermally insulating layer, the method may comprise providing a liquid foam material in the shell, and allowing the foam material to set in the shell to provide at least a portion of the foam thermally insulating layer. The foam may be a polyurethane foam. In some embodiments in which the thermally insulating layer is an expanded foam thermally insulating layer, the method may comprise providing an expandable liquid foam material in the metal shell, and allowing the foam material to expand and set in the shell to provide at least a portion of the expanded foam thermally insulating layer. The expanded foam thermally insulating layer is preferably a polyurethane foam layer e.g. a closed cell polyurethane foam layer as described above. The expandable liquid foam material is provided in the shell after the concrete layer has set. The expandable liquid foam material may be the result of mixing multiple components e.g. first and second components (which may be only first and second components or a greater number of components). As known in the art, the components may be mixed in a given ratio to provide the expandable liquid foam material. The method preferably comprises mixing the components to provide the expandable liquid foam material before or during introduction of the expandable liquid foam material to the metal shell. This may provide more consistent and reliable production of the expandable liquid foam material than would be possible if mixing in the shell. Whenever mixing occurs, it may be achieved manually or using automated mixing means. For example, the components could be mixed in a mixing head of a delivery device or at an earlier stage. Other arrangements may be envisaged in which mixing occurs in the shell. It will be appreciated that the multiple e.g. first and second components that form the expandable liquid foam material will be liquids. The expandable liquid foam material may be injected into the metal shell. The method preferably comprises the step of venting the expanding foam material to allow the escape of air. This may help to prevent air pockets being trapped in the resulting foam structure. While foam materials are preferred, it is envisaged that other liquid materials, whether or not expandable, may be used to provide a thermally insulating layer when set.

It will be appreciated that the expanded foam thermally insulating layer may be built up in portions from quantities of expandable liquid foam material provided in the metal shell, or a single quantity of expandable liquid foam material may be used to provide a desired expanded foam thermally insulating layer. Building up the layer in portions may provide greater control over the layer obtained, and may ensure that the layer fills the shell to a desired degree. The method may comprise building up the thermally insulating filler material in the shell in stages, by providing a quantity of expandable liquid foam material in the shell and allowing the material to expand and set in the shell, and providing a further quantity of expandable liquid foam material in the shell and allowing the further quantity of expandable liquid foam material to expand and set in the shell, and optionally repeating the steps of providing a quantity of expandable liquid foam material in the shell and allowing the material to expand and set in the shell for one or more further quantity of expandable liquid foam material. The method may comprise providing a first quantity of expandable liquid foam material in the metal shell, and allowing the foam material to expand and set in the shell to provide a first portion of the expanded foam thermally insulating layer, and providing a second quantity of expandable liquid foam material in the metal shell, and allowing the foam material to expand and set in the shell to provide a second portion of the expanded foam thermally insulating layer. The steps of providing a quantity of expandable liquid foam material in the metal shell and allowing the foam material to expand and set in the shell may be repeated one or more further times until a desired expanded foam thermally insulating layer is obtained. It is envisaged that the shell may be manipulated between additions of quantities of expandable liquid foam material to help provide an even layer. This may be particularly desirable for more complex shell shapes.

Each quantity of liquid foam material may be formed of multiple components. The quantities of expandable liquid foam material may be introduced into the shell through the same or different parts of the shell e.g. through different ends, openings etc.

In other embodiments, the method may comprise providing a second concrete layer that provides the thermally insulating layer as described below.

In accordance with any of the aspects or embodiments of the invention in which the support element includes a metal shell and a concrete layer preferably the support element is arranged such that heat from the concrete layer is transmitted to a first surface of the metal shell. The first surface of the metal shell is preferably a surface which provides, or is to provide a user or object facing surface of the support element i.e. a first surface thereof when incorporated in outdoor furniture in use. The first surface of the metal shell may be provided by a surface that forms a bottom surface of the shell when used to provide a mould for the concrete layer. The first surface may be a major surface of the shell. The first surface of the metal shell may or may not directly contact a user or object to be supported in use. For example, a surface coating may be provided thereon to decorate or customise the metal shell, provided that it does not interfere with heat transmission to a user or object. The first surface of the metal shell defines an exterior surface of the metal shell, which may provide an exterior surface of the support element.

The (first) concrete layer is preferably bonded to the metal shell, and preferably at least to the interior of the first surface of the metal shell. The concrete layer may directly contact an interior surface of the metal shell. The concrete layer may be bonded to the interior of at least a bottom and optionally sides of the metal shell.

The metal shell may include sides upstanding from the first surface thereof. The sides may be provided by one or more, and preferably a plurality of, sidewalls. The shell may be in the shape of a tray.

In accordance with the invention in any of its aspects or embodiments incorporating a metal shell and a concrete layer, the concrete layer at least partially, and more preferably only partially, fills the metal shell. This may leave space within the shell for other components e.g. a further concrete or other layer, such as a thermally insulating layer.

The metal shell extends over the sides of the concrete layer located therein. Preferably the metal shell extends above the top of the sides of the concrete layer. The concrete layer may include a first surface and an opposite second surface connected by sides of the concrete layer. The first surface of the concrete layer is located toward the first surface i.e. user or object facing surface of the support element and, as appropriate, shell. The metal shell may extend over at least the first surface and the sides of the concrete layer, and optionally over an entirety of the first surface and sides thereof. This will be achieved naturally in the preferred embodiments in which the metal shell acts as a mould during casting of the concrete layer.

Preferably the metal shell includes an opening at an end opposite the first surface thereof. The opening of the metal shell enables concrete to be introduced into the shell in those aspects and preferred embodiments in which the shell acts as a mould for the concrete. The opening may correspond to the entire area of, or at least a portion of an area of the second surface of the support element. The metal shell may include an open end at the end opposite the first surface thereof. Preferably the concrete layer includes a first surface and an opposite second surface connected by sides of the concrete layer, and the metal shell does not extend over at least a portion of the second surface of the concrete layer. The metal shell may define an inwardly directed rim at the open end thereof. The rim may extend over a peripheral portion of the second surface of the concrete layer or support element. The rim may help to retain the content of the shell in place, whether or not any further cover is provided over the opening in the shell, and may provide a surface to which concrete may bond.

In accordance with the invention in any of its aspects or embodiments, including those that do not necessarily include a concrete layer, the metal shell is preferably elongate. The longitudinal sides of the metal shell may be curved. The metal shell may be relatively shallow. The depth or thickness of the metal shell may be chosen as desired, depending upon the intended configuration of the support element.

The metal shell may define the shape of the support element.

In accordance with any of the aspects or embodiments of the invention, the support element may comprise a cover over an opening in the metal shell e.g. over an open end thereof. This may fully enclose the concrete layer (where applicable) and the heating means (and any other components of the support element). The cover may be in the form of a plate. The cover may define at least a portion of the second surface of the support element. The cover may be arranged to overlap a rim and/or a portion of the sides of the metal shell. The cover may be a metal cover e.g. a steel cover. For example, the cover may be provided by a metal backplate. A cover may be used in particular where the second i.e. reverse surface of the support element may be visible in use, e.g. where it forms a back portion of a bench. Where the support element is used as a seat element, the reverse side may not be easily visible, and it may be acceptable to omit a cover. In such embodiments including a concrete layer, the concrete layer (or any other layer superposed thereon) may be exposed and define at least a portion of the second surface of the support element. The cover may be provided with a surface decoration to provide an attractive finish.

The method of the present invention may comprise locating a cover over the metal shell. In embodiments including a concrete layer, this may be carried out after curing of the concrete layer or layers. In embodiments in which a thermally insulating layer in the form of an expanded foam layer that has expanded in the shell is provided, the method may comprise locating the cover over the metal shell before providing an expandable liquid foam material in the shell for providing at least a portion of the expanded foam layer. The cover may then help to confine the liquid foam material during expansion. The metal shell and/or cover may then comprise one or more openings to permit the expandable liquid foam material to be introduced into the metal shell. In some preferred embodiments, a longitudinal end of the shell comprises one or more openings for this purpose. Preferably one or more vent hole is provided in the shell and/or cover to allow air to escape as the expandable foam material expands. Any opening(s) may be suitably covered after use, e.g. by an end plate. The method may comprise providing the concrete mix in the metal shell, and allowing the concrete mix to set with the metal shell in a first orientation, locating a cover over the metal shell, and rotating the covered metal shell through 90 degrees before providing the expandable liquid foam material in the shell. The cover may be located over an opening of the metal shell through which the concrete mix was introduced. In embodiments in which the shell is elongate, the shell may be moved from a horizontal orientation to a vertical orientation for introduction of the expandable liquid foam material, preferably through a longitudinal end of the shell. This may facilitate uniform expansion of the foam. It is desirable for the liquid foam material to be introduced through a highest point of the shell to reduce the likelihood of air pockets being trapped in the foam. As mentioned above, the expandable liquid foam material may be the result of mixing multiple e.g. first and second components. The multiple e.g. first and second components are preferably mixed to provide the expandable liquid foam material, before or during introduction of the expandable liquid foam material to the shell, whether manually or using automated mixing means. This may ensure that the components are thoroughly mixed in a desired ratio. However, it is not excluded that in other arrangements, the components of an expandable liquid foam material might be introduced through the opening(s) for mixing in the shell.

In accordance with the invention in any of its aspects or embodiments, including those that do not necessarily include a concrete layer, the metal shell, or at least a main body thereof, may be formed of any suitable material or materials. In preferred embodiments at least a main body of the metal shell is of steel. It will be appreciated that different types of steel may be selected for the metal shell depending upon the intended use of a support element in the furniture. For example, a metal shell, or at least a main body thereof, of a support element for forming part of a seat portion of a bench may be of stainless steel, with a metal shell, or at least a main body thereof, of a support element for forming part of a back portion of a bench may be of mild steel. However, other materials may be used e.g. aluminium. It will be appreciated that the metal shell should have suitable thermal conduction properties at least to enable heat to be transferred from the concrete layer (or, in those further aspects and embodiments of the invention which do not necessarily include a concrete layer, from the heating means) to a user. At least a main body of the metal shell may be of any of the above materials, and, in some embodiments, the entire metal shell may be of such materials. The metal shell may therefore be a steel or aluminium shell. The main body of the metal shell may correspond to the entirety of the metal shell, or the shell may further comprise other formations e.g. ribs joined to the main body as discussed below. The main body of the metal shell may define the shape of the metal shell. The thickness of the metal shell may be of any desired range, and this may depend upon factors such as the material of the shell, and the intended content. In some exemplary embodiments, the metal shell has a thickness of less than 5mm. A main body of the metal shell may be formed of multiple pieces joined together to provide a unitary main body. For example, the main body of the metal shell may comprise an intermediate portion and separate (longitudinal) end portions. However, in preferred embodiments the main body of the metal shell is of a single piece. The main body of the metal shell may be formed from a single blank of metal e.g. steel. The main body of the metal shell is preferably continuous. However it is constructed, in those aspects and embodiments in which the metal shell provides a mould for concrete during casting, the shell should be constructed appropriately to hold the liquid concrete and enable it to act as a mould for the concrete as it dries.

The following features relate particularly to those aspects or embodiments including a concrete layer.

Preferably the concrete layer extends the full length and width of the shell. The layer may be a continuous layer.

The support element may comprise one or more formations to facilitate adherence between the shell and the concrete layer (or a further concrete layer where provided as discussed below). Such elements may be associated with the metal shell. The ribs described below preferably cooperate with the heated concrete layer. However, they may alternatively cooperate with a further concrete layer where provided.

In some embodiments the metal shell comprises one or more, and preferably a plurality of ribs extending from an interior surface of the main body of the metal shell which contact the concrete layer in the metal shell. The rib or ribs may have any desired orientation. A plurality of parallel ribs may be provided. The ribs may be evenly spaced. The or each rib is preferably a longitudinally extending rib. A plurality of such ribs may be spaced across a width of the shell. The or each rib preferably extends substantially an entire length of the metal shell. The or each rib may extend continuously or discontinuously in the longitudinal direction.

The one or more ribs may extend from an interior of a first surface of the main body of the metal shell. Preferably the or each rib is a metal rib. The or each rib may be of the same material as the main body of the metal shell. The rib(s) may be integrally formed with the main body of the shell, or may be provided by one or more separate elements attached e g. welded thereto. In preferred embodiments, the main body of the metal shell is a single piece main body as described above, and the ribs are separate elements attached thereto. The rib(s) may help to reinforce the metal shell, and may aid setting of the concrete, and adherence between the shell and the concrete layer. In some embodiments, the or each rib comprises one or more openings therethrough through which concrete of the concrete layer has flowed (or in the case of the method, may flow) to create a concrete pillar facilitating bonding between the shell and the concrete layer. Preferably the or each rib comprises a plurality of such openings spaced along the length thereof. Providing the metal shell with one or more ribs may be advantageous in facilitating bonding between the shell and the concrete in accordance with the invention where the concrete layer contacts the ribs, as the shell is to form part of the support element in a final product. It is important to ensure that there is a secure connection between the concrete and the shell. It will be appreciated that in some cases, the support element may even be mounted such that an open end of the shell lies lowermost. It has been found that concrete may suitably adhere to the metal shell after curing therein to avoid the need for any additional fixing means. Nonetheless, the use of ribs may help to increase the security of bonding.

The height of a rib may be selected as desired to provide appropriate bonding to a concrete layer (whether the first or a further concrete layer as discussed below). Preferably the or each rib has a height that is no greater than the thickness of the concrete layer. A rib may have a height that is at least 30% or at least 50% of a thickness of the concrete layer. The or each rib may have a height of a least 0.005m or at least 0.008 m. However, these ranges are merely exemplary, and a wide range of dimensions may be applicable depending upon the intended use of the support element and the thickness of the concrete layer.

While the use of ribs is particularly beneficial in the context of a support element that includes a concrete layer, it is envisaged that ribs could equally be provided in a support element that does not include a concrete layer. Such ribs may be in accordance with any of the embodiments described above. In other embodiments the shell may be free of ribs.

In accordance with the invention in any of its aspects or embodiments including a concrete layer, the support element may include only a single concrete layer. There may therefore only be one concrete layer located in the metal shell. However, in some embodiments the concrete layer is a first concrete layer and the support element further comprises a second concrete layer located in the metal shell. The second concrete layer may be superposed on the first concrete layer. The metal shell preferably extends over at least the sides of the second concrete layer. Preferably the first concrete layer is located between the first surface e.g. a bottom of the metal shell and the second concrete layer. The first and second concrete layers may directly contact one another. In preferred embodiments in which the metal shell has provided a mould for the first concrete layer during casting, the metal shell has also provided a mould for the second concrete layer during casting. The second concrete layer is preferably located between the first concrete layer and a second surface of the support element. The first and second concrete layers may be coextensive with one another. It will be appreciated that the use of the metal shell makes it possible to use different types of concrete layer in the support element without detriment to the appearance of the element, as the layers may be located within the shell, such that the non-homogeneous multi-layer concrete structure need not be visible to a user.

Preferably the second concrete layer has at least one different property than the first concrete layer. The first and second concrete layers are preferably of different types of concrete. The properly may be one or more of; thermal conductivity, electrical conductivity and density. The properties of the first and second concrete layers may be selected to complement one another.

In accordance with the method of the present invention, the concrete mix introduced into the shell may be a first type of concrete mix to provide a first concrete layer, and the method may comprise introducing a second, different type of concrete mix into the shell to provide a second concrete layer. The second, different type of concrete mix is preferably introduced into the shell subsequent to the introduction of the first concrete mix. The second concrete layer may have different properties to the first concrete layer, as described above. The method may comprise allowing the first concrete layer to at least partially set before introducing the second type of concrete mix. For example, the first concrete layer may be allowed to set for at least 1 -2 hours. The second concrete mix may differ in the ratio and/or composition of its ingredients. In preferred embodiments the first and second concrete mixes comprise different aggregate materials. The method of forming the support element may comprise using a concrete mix including any of the materials discussed in relation to the respective first and second concrete layers to obtain a concrete layer comprising the material(s).

In some preferred embodiments the second concrete layer has greater thermal insulation properties than the first concrete layer. The second concrete layer may then provide the thermally insulating layer between the heating means and the second surface of the support element. This may obviate the need for a non-concrete thermally insulating layer e.g. board. The second concrete layer may be coextensive with the first concrete layer, helping to reduce thermal losses over the entire area of the first concrete layer. A support element comprising a mixture of a first concrete layer selected to provide low density, and a second concrete layer selected to provide advantageous thermal insulation properties may be advantageous in providing an element that is both lightweight and thermally efficient in contrast to prior art elements which contained only one type of concrete, required to impart all strength properties to the element. The ability to do this may stem from the presence of the metal shell as previously described.

Alternatively or additionally, the second concrete layer may have greater electrical insulation properties than the first concrete layer. This is particularly useful in those embodiments in which an electric current is passed through one or more portions of a first concrete layer that is electrically conductive to generate heat therein. The second concrete layer may then provide electrical insulation between the first concrete layer and the second side of the support element. It will be appreciated that the second concrete layer may provide both electrical and thermal insulation properties, and may have greater thermal and electrical insulation properties than the first concrete layer. The second concrete layer may then simultaneously provide both a thermally insulating layer between the first concrete layer and the second surface of the support element, and a thermally conductive layer between the first concrete layer and the second surface of the support element

In preferred embodiments the second concrete layer comprises a clay-based aggregate material. It has been found that that this type of concrete provides a combination of both good thermal and good electrical insulation properties. This type of layer is useful whether or not the heating means is arranged to pass current directly through the first concrete layer. Such concrete materials may be relatively low density, and therefore also provide an advantageously light weight second concrete layer. Such a second concrete layer is advantageously combined with a first concrete layer comprising a carbon based e.g. graphite aggregate material. In some embodiments the first concrete layer does not include a clay based aggregate material and the second concrete layer does not include a carbon based e.g. graphite aggregate material.

The support element is preferably arranged such that there is no heating means for heating the second concrete layer. The second concrete layer preferably does not have heating means associated therewith. The second concrete layer preferably does not include any heating element embedded in the concrete layer for providing heat thereto, or means for passing an electrical current therethrough.

The first and second concrete layers may be of the same or different thicknesses.

The first and second concrete layers preferably directly contact one another to define a multilayer concrete structure. Of course, one or more additional concrete layers may also be provided in the concrete shell, although preferably only one or two concrete layers are provided.

Although the second concrete layer is preferably located so that it is introduced into the shell after the first concrete layer, or so that the first concrete layer is between the second concrete layer and the first surface of the metal shell, it is envisaged that the layers could be located the other way around, in the event that heat is intended to be transmitted to a user or object through a different surface of the support element e.g. defined at least in part by the first concrete layer or a thermally conductive component of the support element e.g. a cover of the shell. In such embodiments, any ribs associated with the shell may cooperate with the second concrete layer rather than the first. Any of the features described in relation to the ribs, or other formation for facilitating bonding with a concrete layer, may then apply to the second concrete layer rather than the first. Provided that a concrete layer adjacent the shell e.g. the first concrete layer, is adequately bonded to the shell, a further concrete layer may secured through bonding to that (first) concrete layer. Of course, additional formations may be provided to facilitate bonding of a further concrete layer to the shell e.g. associated with the sides of the shell, or another component of the support element. It will be appreciated that even where no second concrete layer is used, the concrete layer i.e. the first concrete layer referred to herein, might be spaced from the interior of the first surface of the metal shell by another component or layer (or a second concrete layer may, where provided, be spaced in such a manner from the first surface of the shell).

In accordance with any of the aspects and embodiments of the invention, whether or not a concrete layer is present, the exterior of the metal shell e g. the exterior of the first surface of the shell may be provided with a surface coating and/or printed to enhance aesthetic appeal. For example, a logo may be provided thereon.

In accordance with the invention in any of its aspects or embodiments, whether or not a concrete layer is present, the shape of the support element may be selected as desired, taking into account the intended use of the element in the outdoor furniture. The support element has a width and a length. The support element also has a thickness. The support element is preferably of a regular shape.

The first surface of the support element may be polygonal, e.g. rectilinear, such as square or rectangular in shape. The support element may be polygonal, e g. rectilinear, such as square or rectangular in longitudinal and/or transverse cross section. Such shapes are particularly useful where the support element is to provide support to a user when sitting. The support element is preferably non-cylindrical.

The support element is preferably elongate. The length may be at least twice the width of the support element.

In preferred embodiments the support element is in the form of a beam.

The support element may be of any desired length, depending upon the type of outdoor furniture of which it is to form part. In some embodiments the length of the support element is no greater than 2m. The length of the support element may be at least 0.5 m or at least 1 m. The length of the support element may be in the range of from 0.5m-2 m, and preferably from lm-2m.

The width of the support element may be at least 0.1 m, or at least 0.5 m, and may be no greater than 0.8m. The width of the support element may, for example, be in the range of from 0.2- 0.7m.

By way of example, a thickness of the support element may be in the range of no greater than 0.25m, or no greater than 0.15m, or no greater than 0. lm. The thickness of the support element may be at least 0.04m. Alternatively or additionally, the thickness of the (or each) concrete layer, where provided, may lie in any of these ranges. In some embodiments the or each concrete layer has a thickness of no greater than 0.2 m, or 0.1 m. In some preferred embodiments the or each concrete layer has a thickness of no greater than 0.05 m, or no greater than 0.04 m. The or each concrete layer may have a thickness of at least 0.01m, and preferably at least 0.015m. Such preferred ranges are particularly, although not exclusively applicable to providing a support element for a bench.

Where multiple concrete layers are provided, a (second) concrete layer providing a thermally insulating function may be thicker than a first, heated concrete layer. The thickness of a heated concrete layer may depend upon the type of heating arrangement used. For example, a layer that is heated through the use of a separate heating element may be thicker than an electrically conductive concrete layer to which an electrical current is applied to achieve heating. As mentioned previously, where a heating panel is used to provide the heating means, it is possible to make the concrete layer thinner than when other types of heating element are used. These relative dimensions for first and second concrete layers, and depending upon the type of heating means used, are applicable independently or in combination with the above numerical ranges for the thickness of the concrete layers. The or each concrete layer may be of uniform thickness.

The dimensions of a support element may be any combination of the above ranges, and any particular dimension range may be used independently of any other range disclosed.

The above exemplary ranges of dimensions are particularly, although not exclusively, applicable to outdoor furniture in the form of a bench. It will be appreciated that the dimensions and configuration of the support element may vary within a wide range, depending upon the intended application of the element, and the above ranges are merely exemplary.

As discussed earlier, the use of heating panel(s) enables the heated concrete layer to be made thinner. In particular, the concrete layer may be freed from the constraint of needing to be of a thickness to enable a conventional heating element e.g. cable to be embedded therein. The metal shell may then be filled by a thermally insulating filler material, e.g. a thermally insulating foam. Preferably the filler material is an expanded filler material such as an expanded foam. Preferably the filler material has expanded in the shell. It may be desirable to maintain a concrete layer, albeit a thin layer, as this helps to evenly distribute heat, and may retain heat longer. However, as discussed below in relation to some further aspects of the invention, the Applicant has realised that in some contexts it may be desirable to omit the concrete layer altogether.

It has been recognised that the metal shell enables layers of different materials to be included in the support element to provide an element with desired properties, while maintaining the required strength of the element. As described with reference to the earlier aspects and embodiments of the invention involving the use of the concrete layer, the metal shell is key in opening up new possibilities in the construction of the element, freeing the other components from the constraint of having to provide significant levels of strength to the element. The use of a metal shell in providing a support element for heated outdoor furniture is therefore considered to be advantageous in its own right, whether or not a concrete layer is included. The present invention in some further aspects relates to a support element for heated outdoor furniture that may not necessarily include a concrete layer.

In accordance with a further aspect of the invention there is provided; a support element for heated outdoor furniture, the support element comprising; a metal shell; a thermally insulating filler material located in the shell; and heating means for providing heat to the shell when energised in use, wherein the heating means is disposed between the thermally insulating filler material and an interior surface of the shell.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith. For example, the materials and shape of the shell and support element may be in accordance with any of the earlier described embodiments.

In these aspects of the invention, the thermally insulating filler material is preferably a non-concrete filler material.

It is envisaged that the shell may include a concrete layer as in the earlier aspects and embodiments. A concrete layer may assist with heat retention and distribution as discussed above. However, the support element is preferably free from concrete. Thus, the support element does not include a concrete layer therein This has the advantage that the support element may be made considerably fighter than in those earlier aspects or embodiments in which the shell includes a concrete layer. This may reduce shipping costs associated with the support element, and facilitate installation The support element may be particularly suitable for use in providing portable, or at least non fixed installations. Installation or movement of furniture including the element may raise fewer issues in terms of having to comply with health and safety regulations that might apply to a heavier object. It has also been found that the support element may heat up more quickly than would be possible for an element containing concrete. This may provide greater convenience and efficiency for users. These embodiments may therefore be particularly suitable for a domestic user.

While it is envisaged that any type of heating means may be used, including the other types of heating means described above in relation to the earlier aspects of the invention, preferably the heating means comprises one or more heating panel disposed between the thermally insulating filler material and the interior surface of the shell. As discussed earlier, a heating panel may conform to a surface to be heated. A heating panel defines a surface for transmitting heat to a surface to be heated i.e. to the interior of the shell. A major surface of the heating panel may be located in face to face relationship with the surface to be heated. The or each heating panel preferably conforms to the interior surface of the shell. Each heating panel may extend over at least a portion of the interior surface of the shell to which it is desired to impart heat. The or each heating panel is preferably attached to the interior surface of the shell, and most preferably adhesively attached. The heating panel may be supplied with an adhesive layer already present for this purpose, and/or adhesive may be applied to the shell and/or panel. Preferably the or each heating panel is directly attached to the interior surface of the shell via adhesive. However, it will be appreciated that the heating panel need not necessarily be directly attached to the shell, provided that heat may be conducted from the panel to the shell i.e. the panel is in thermal contact with the interior of the shell. The or each heating panel may thus directly or indirectly heat the interior of the shell. For example, it is envisaged that the shell may include a concrete layer, the or each heating panel being sandwiched between the concrete layer and the thermally insulating filler material. The concrete layer may then distribute heat throughout the interior of the shell and aid heat retention. A thin concrete layer may be used in this context. Preferably, however, the or each heating panel is sandwiched between the interior surface of the shell and the thermally insulating filler material. The or each heating panel preferably contacts the thermally insulating filler material. In some embodiments the or each heating panel is directly attached to the shell on one side thereof, and the thermally insulating material on the other side thereof. It will be appreciated that the direct attachment on one or both sides may be via an adhesive layer. Where multiple heating panels are provided, these may be associated with different parts of the interior of the shell. For example, one heating panel may be associated with a portion of the shell that is to form the seat portion of a seat e.g. bench, while another may be associated with a portion of the shell that is to form the back portion of the seat e.g. bench. Multiple heating panels may be spaced from one another.

It has been found that in embodiments using heating panel(s), as the heating panel(s) may conform to the interior surface of the shell, a wider range of shapes for the shell may be used. For example, the shell may more readily incorporate curved portions. The shell may be designed to have any desired freeform shape. An item of outdoor furniture may more readily be provided using a single such support element. For example, a seat may include only a single support element having a shell which has been shaped to define a seat portion and a back portion. Freedom in shaping the support element may be enhanced by the absence of concrete in preferred embodiments. The outdoor furniture may include a single support element. The outdoor furniture may or may not include a frame. In some embodiments the outdoor furniture may not include a frame. It will be appreciated, however, that the furniture need not be constructed in this way, and the support element may be used to provide outdoor furniture in any of the manners described below, which are applicable to all aspects and embodiments of the invention.

In accordance with these further aspects of the invention using one or more heating panel, the panel may be in accordance with any of the embodiments earlier described.

The heating means may comprise a single heating panel, or a plurality thereof. The or each heating panel may conform to a surface to be heated. The following features described in relation to a heating panel are applicable to at least some, or to the or each such panel that is present. Where a plurality of heating panels are provided, each heating panel may be of identical construction. It will be appreciated that, unless otherwise stated, one or more additional heating panels may be present, in addition to one or more such panels, whose construction and/or location is defined, or such one or more heating panel may be the only such heating panels present.

Preferably the heating panel is a flexible heating panel. Such a heating panel may be readily used to provide heat to any shaped surface, and may conform closely to the surface to transmit heat thereto. However, it is envisaged that a non-flexible heating panel may be used that is shaped to conform to the surface to be heated (i.e. to the portion thereof that the heating panel is in thermal contact with). The heating panel should have a corresponding shape to the surface to be heated. For example, a flat heating panel may be used where the surface is a flat surface. Other shaped heating panels may be envisaged that have a shape corresponding to the surface to be heated e.g. including a curved portion or portions. Thus, the heating panel may be a flexible heating panel or a panel that is shaped to correspond to the shape of the surface to be heated. A heating panel comprises a heating element. Where the heating panel is a flexible panel, the heating element is flexible. The heating element may be of any suitable construction. The heating element may, for example, be a wire wound or etched foil heating element. Such heating elements are particularly applicable to flexible heating elements. The heating element may be a printed element. The heating element may be a thick film element.

The heating element (and the heating panel) may be substantially planar. The heating panel may be of a laminate construction. The heating panel may comprise a heating element layer disposed between outer substrate layers. In particularly preferred embodiments in which the heating panel is a flexible heating panel, the outer substrate layers may be silicone rubber layers. Additional layers may be present, such as an adhesive layer for attaching the heating panel to a substrate e.g. the metal shell. The heating panel may be of a thin construction. The heating panel may be sheet-like. Preferably the heating panel has a thickness of less than 5 mm. In some preferred embodiments, the heating panel is a flexible heating panel in the form of a heat mat, such as a silicone rubber heat mat. However, it will be appreciated that other types of heating panel may be suitable.

It will be appreciated that a flexible heating panel as referred to herein in any of the aspects or embodiments of the invention is flexible to enable it to conform to a surface to be heated when applied thereto. The heating panel is inherently flexible. However, in the resulting support element, the flexible heating panel typically will be constrained by the rigidity of the component(s) to which it is applied, and will not be free to flex. Preferably the one or more heating panels provide the only heating means for the support element i.e. no conventional heating cable is present.

One or more heating panel may be disposed in any suitable manner with respect to the shell for supplying heat thereto. Heating panels may be customised to a wide range of shapes and sizes. It will be appreciated that the aspect ratio of the heating panel may be chosen as desired to provide a given surface area coverage, e.g. depending upon the shape of the shell to be heated. One or more such heating panel may therefore be used to provide a suitable surface area coverage for a desired application.

The heating means enables the shell of the support element to be heated when the element is incorporated in outdoor furniture. The heating means is electrical heating means. The heating means is energised through connection to an electrical power supply in use. The support element may further comprise means for connecting the heating means to a power supply for supplying electrical energy to the heating panel, (or other heating element), in use e g. one or more set of terminals and/or one or more connectors. The heating means may be arranged to generate heat in substantially the entire width and/or length of the shell, or a portion or portions thereof.

In these further aspects and embodiments of the invention, the support element is arranged such that heat provided by the heating means to the shell in use may be transmitted to a user of outdoor furniture including the support element in use, and/or to an object supported by such furniture. The support element therefore comprises a heated support surface. Any reference to a user facing or supporting surface herein may be interchangeable with an object facing or supporting surface. Preferably, however, the support element is used to provide support to a user of outdoor furniture, and is arranged to transmit heat to a user of the furniture.

As described earlier, the support element may comprise a first surface intended to face a user or object in use to provide support thereto. Heat may then be transmitted to a user or object via the first surface in use. The support element may comprise an opposite second surface intended to face away from a user or object supported by the support element in use. The second surface is preferably unheated.

The support element is arranged such that heat from the heating means is transmitted to a first surface of the metal shell. The first surface of the metal shell is preferably a surface which provides, or is to provide a user or object facing surface of the support element i.e. a first surface thereof when incorporated in outdoor furniture in use. The first surface of the metal shell may be provided by a surface that forms a bottom surface of the shell when the heating means is located therein. The first surface may be a major surface of the shell. The first surface of the metal shell may or may not directly contact a user or object to be supported in use. For example, a surface coating may be provided thereon to decorate or customise the metal shell, provided that it does not interfere with heat transmission to a user or object. The first surface of the metal shell defines an exterior surface of the metal shell, which may provide an exterior surface of the support element.

The thermally insulating filler material preferably contacts the metal shell. The thermally insulating filler material may contact the interior of at least the sides (and optionally a part of the bottom) of the metal shell. It will be appreciated that the filler material will not contact the shell in regions where a heating panel is attached to the shell.

The metal shell may include sides upstanding from the first surface thereof. The sides may be provided by one or more, and preferably a plurality of, sidewalls. The shell may be in the shape of a tray. The thermally insulating filler material at least partially, and in some embodiments, completely fills the metal shell.

The thermally insulating filler material may define a body e.g. layer of thermally insulating filler material in the shell. The metal shell extends over the sides of the body e.g. layer of thermally insulating material located therein. The body of thermally insulating material may include a first surface and an opposite second surface connected by sides of the body. The first surface of the body of thermally insulating material is located toward the first surface i.e. user or object facing surface of the support element and, as appropriate, shell. The metal shell may extend over at least the first surface and the sides of the body of thermally insulating material, and optionally over an entirety of the first surface and sides thereof. This will be achieved naturally in the preferred embodiments in which the metal shell acts as a mould during setting of the thermally insulating material.

Preferably the metal shell includes an opening at an end opposite the first surface thereof. The opening of the metal shell enables the heating means e.g. one or more heating panels to be introduced into the shell. The opening may correspond to the entire area of, or at least a portion of an area of the second surface of the support element. The metal shell may include an open end at the end opposite the first surface thereof. The thermally insulating filler material may be in the form of a body e.g. layer of thermally insulating filler material including a first surface and an opposite second surface connected by sides thereof, and the metal shell may not extend over at least a portion of the second surface of the body. The metal shell may define an inwardly directed rim at the open end thereof. The rim may extend over a peripheral portion of the second surface of the body of thermally insulating material or support element.

The metal shell may define the shape of the support element.

Preferably the support element comprises a cover over an opening in the metal shell e.g. over an open end thereof. This may fully enclose the thermally insulating filler material and the heating means (and any other components of the support element). The cover may be in the form of a plate. The cover may define at least a portion of the second surface of the support element. The cover may be arranged to overlap a rim and/or a portion of the sides of the metal shell. The cover may be a metal cover e.g. a steel cover. For example, the cover may be provided by a metal backplate. A cover may be used in particular where the second i.e. reverse surface of the support element may be visible in use, e.g. where it forms a back portion of a bench. The cover may be provided with a surface decoration to provide an attractive finish. The cover may also facilitate manufacture in preferred embodiments in which the thermally insulating filler material is an expanded material, as described below.

The thermally insulating filler material at least partially fills the interior of the shell. The material preferably conforms to the internal contour of the shell. While the shell may contain only the heating means and the thermally insulating filler material, it will be appreciated that other material e.g. layers may be present. The thermally insulating filler material is preferably an expanded filler material. The thermally insulating filler material is preferably a foam material, and most preferably an expanded foam material. In particularly preferred embodiments the shell has acted as a mould for the filler material e.g. foam material during setting, and preferably during expansion. The foam material is preferably a rigid foam material. The foam material is preferably a closed cell foam material. The foam material may be a polyurethane foam material. In a particularly preferred embodiment the thermally insulating filler material is an expanded polyurethane foam material.

The present invention extends to a method of making a support element for heated outdoor furniture in accordance with the invention in these further aspects or embodiments.

The method may comprise providing the metal shell, providing a liquid filler material in the metal shell, and allowing the material to set in the shell to provide a thermally insulating filler material for the shell. The liquid filler material is a material which sets to provide a thermally insulating filler material. In preferred embodiments the liquid filler material is an expandable liquid filler material, and the method comprises allowing the material to expand and set in the shell to provide an expanded thermally insulating filler material for the shell. The liquid filler material is preferably a non-concrete material. Preferably the liquid filler material is a liquid foam material, as described above.

The method may further comprise the step of providing the means for heating the shell when energised.

In accordance with a further aspect of the invention there is provided a method of forming a support element for heated outdoor furniture, the method comprising: providing a metal shell shaped to act as a mould; providing means for heating the metal shell when energised; providing a liquid filler material in the metal shell, the liquid filler material being a material which provides a thermally insulating filler material when set, and allowing the filler material to set in the shell to provide a thermally insulating filler material in the shell.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith.

It will be appreciated that the method of this aspect of the invention may provide a support element in accordance with any of the aspects or embodiments of the invention described herein. Similarly the support element in accordance with any of the aspects or embodiments of the invention may be produced using a method according to any of the embodiments described herein, to the extent that it is not incompatible therewith.

Preferably the heating means comprises one or more heating panels arranged to provide heat to the interior surface of the shell. Preferably in these further aspects and embodiments of the invention, the method comprises disposing the one or more heating panels in thermal contact with the interior surface of the metal shell. The or each heating panel is preferably disposed in the shell before the liquid filler material is disposed therein. The method may comprise adhesively attaching the or each heating panel to an interior surface of the shell. The method may further comprise providing a suitable electrical connection e.g. a set of one or more terminals and/or one or more connectors for providing electrical power to the or each heating panel (or other heating element). In some embodiments, it is envisaged that a concrete layer may be provided in the shell and allowed to set before the one or more heating panels are disposed therein. The or each heating panel may then be attached to the surface of the concrete layer once set as described in the earlier aspects and embodiments. However, preferably the support element does not include a concrete layer, and the or each heating panel is in direct thermal contact with the interior of the shell (and optionally attached thereto).

The filler material sets in the shell to provide a body of thermally insulating filler material in the shell.

The liquid filler material is preferably an expandable filler material. The method preferably comprises allowing the expandable liquid filler material to expand and set in the shell to provide an expanded thermally insulating filler material in the shell. Preferably the liquid filler material is a liquid foam material to provide a thermally insulating foam material in the shell, and most preferably is an expandable foam material for providing an expanded foam material in the shell. Preferably the foam material is a polyurethane material.

In those aspects or embodiments using an expandable liquid filler material, in particular an expandable liquid foam material, the material is preferably the result of mixing multiple e.g. first and second components. At least first and second components may be used, (which may be more than two, or only two components). Thus the first and second components may be replaced by a reference to "multiple" components. Preferably the method comprises mixing the components which provide the expandable liquid filler to provide the expandable liquid filler material before or during introduction of the expandable liquid filler material to the shell. This may be achieved manually or using automated mixing means. The components could be mixed in a mixing head of a delivery device, or at an earlier stage. Mixing of the components to provide the expandable liquid filler material in this way may enable a desired ratio of components to be more reliably mixed than if mixing in the shell, and hence more reliable production of an expanded fdler material. However, other arrangements may be envisaged. For example mixing may occur within the metal shell. It will be appreciated that the multiple e g. first and second components that form the expandable liquid filler material will be liquids. The expandable liquid filler material may be injected into the metal shell. In some embodiments the method may comprise providing multiple e g. first and second components which, when mixed, provide an expandable liquid filler (e g. foam) material, and mixing the components to provide the expandable liquid filler material. The method may comprise introducing the expandable liquid filler material into the shell. The mixing may occur before or during introduction of the expandable liquid filler into the shell.

It will be appreciated that the body of expanded filler material in the shell may be built up in portions from quantities of expandable liquid filler material provided in the metal shell, or a single quantity of expandable liquid filler material may be used to provide a desired body of expanded thermally insulating filler material. Building up the filler material in portions may provide greater control over the body of material obtained, and may ensure that the material fills the shell to a desired degree. The method may comprise building up the thermally insulating filler material in the shell in stages, by providing a quantity of expandable liquid filler material in the shell and allowing the material to expand and set in the shell, and providing a further quantity of expandable liquid filler material in the shell and allowing the further quantity of liquid filler material to expand and set in the shell, and optionally repeating the steps of providing a quantity of expandable liquid filler material in the shell and allowing the material to expand and set in the shell for one or more further quantity of expandable liquid filler material. The method may comprise providing a first quantity of expandable liquid filler e.g. foam material in the metal shell, and allowing the filler material to expand and set in the shell to provide a first portion of the body of expanded thermally insulating material, and providing a second quantity of expandable liquid filler material in the metal shell, and allowing the filler material to expand and set in the shell to provide a second portion of the body of expanded thermally insulating material. The steps of providing a quantity of expandable liquid filler material in the metal shell and allowing the material to expand and set in the shell may be repeated one or more further times until a desired body of expanded thermally insulating filler material is obtained in the shell. It is envisaged that the shell may be manipulated between additions of quantities of expandable liquid filler material to help provide more even filling. This may be particularly useful where the shell is of a more complex shape. Each quantity of expandable liquid filler material may be formed from mixing multiple e g. first and second components. The quantities of liquid filler material may be introduced through the same or different parts of the shell e g. through different ends, openings etc.

Preferably the method comprises the step of venting the expanding filler e g. foam material to allow the escape of air. This may help to prevent air pockets being trapped in the resulting filler e g. foam structure.

In preferred embodiments in which the support element comprises a cover over an opening in the metal shell e.g. over an open end thereof, the method comprises locating the cover over the opening before introducing the expandable liquid filler material e.g. foam material to the interior of the shell. The metal shell and/or cover may then comprise one or more openings to permit the expandable liquid filler e.g. foam material to be introduced into the metal shell. In some preferred embodiments, a longitudinal end of the shell comprises one or more openings for this purpose. Preferably one or more vent hole is provided in the shell and/or cover to allow air to escape as the expandable foam expands. Any opening(s) may be suitably covered after use, e.g. by an end plate. The method may comprise providing one or more heating panels in the metal shell with the metal shell in a first orientation, locating a cover over the metal shell, and rotating the covered metal shell through 90 degrees before providing the expandable liquid filler e.g. foam material in the shell. In general, in embodiments in which the shell is elongate, the shell may be moved from a horizontal orientation to a vertical orientation for introduction of the expandable liquid filler e g. foam material, or the components thereof. This may facilitate uniform expansion of the filler e.g. foam. As mentioned above, the expandable liquid filler material may be the result of mixing multiple e.g. first and second components. The multiple e.g. first and second components are preferably mixed, whether manually or using a mixing machine, before or during introduction of the expandable liquid filler material to the shell. The mixing may occur in a mixing head of a delivery device introducing material through the opening or at an earlier stage. This may ensure that the components are thoroughly mixed in a desired ratio. However, it is not excluded that in other arrangements, the components of an expandable liquid filler material might be introduced through the opening(s) for mixing in the shell. However the material is introduced, it is desirable that the liquid filler material is introduced through a highest point of the shell to reduce the likelihood of air pockets being trapped in the foam.

In accordance with a further aspect of the invention there is provided a method of forming a support element for heated outdoor furniture, the method comprising: providing a metal shell shaped to act as a mould; providing means for heating the metal shell when energised; providing an expandable liquid filler material in the metal shell, the liquid filler material being a material which provides a thermally insulating filler material when expanded and set, and allowing the filler material to expand and set in the shell to provide an expanded thermally insulating filler material in the shell.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith. Preferably the expandable liquid filler material is a foam material e.g. polyurethane. The liquid filler material may be added in stages, with each quantity of liquid filler material being provided in the shell, and allowed to expand and set, before a further quantity is provided in the shell and allowed to expand and set. A cover may be used as described above. The shell may be rotated as described above.

In accordance with a further aspect of the invention there is provided; a support element for heated outdoor furniture, the support element comprising; a metal shell shaped to act as a mould; means for heating the metal shell when energised; and an expanded thermally insulating filler material located in the shell, wherein the thermally insulating filler material has expanded and set in the shell with the shell acting as a mould for the material.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith. Preferably the expandable liquid filler material is a foam material e.g. polyurethane.

In accordance with a further aspect of the invention there is provided a support element for heated outdoor furniture, the support element comprising; a metal shell; a filler material located in the shell; and means for heating the filler material and/or the metal shell to impart heat to the shell when energised in use.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith.

In these aspects of the invention, the metal shell, filler material and heating means may be in accordance with any of the aspects and embodiments of the invention earlier described. In one set of embodiments, the filler material may be a concrete layer. In another set of embodiments, the filler material may be a thermally insulating filler material e g. an expanded thermally insulating filler material. The thermally insulating filler material may be a foam. The filler material is preferably in the form of a body e.g. layer. One or more additional layers of different materials may be present. For example, in embodiments in which the filler material is concrete, a layer of a different concrete material may be present, and/or a thermally insulating e.g. foam layer. In embodiments in which the filler material is a thermally insulating material e.g. a foam, a concrete layer may additionally be present, or the element may be free from concrete. The heating means may be of any of the constructions described above, e.g. a heating panel, or may comprise one or more conventional heating elements.

Preferably the shell has acted as mould for the filler material during setting thereof, and, in particularly preferred embodiments where the filler material is an expanded material, during expansion thereof.

The present invention extends to a method of making a support element for heated outdoor furniture in accordance with the invention in these further aspects or embodiments.

The method may comprise providing the metal shell, providing liquid filler material in the metal shell, and allowing the filler material to set in the shell to provide a filler material for the shell. The filler material may be a thermally insulating filler material, such as a foam. The liquid filler material will then be a material which provides such a filler when set. The liquid filler material may be an expandable filler material, such as an expandable foam filler material as described above. The method may comprise allowing the expandable filler material to expand and set in the shell to provide an expanded filler material in the shell. The filler material may be a non-concrete material. Alternatively the filler material may be a concrete filler. The method may further comprise the step of providing the means for heating the shell when energised.

In accordance with a further aspect of the invention there is provided a method of forming a support element for heated outdoor furniture, the method comprising: providing a metal shell shaped to act as a mould; providing a liquid filler material in the metal shell, and allowing the material to set in the shell to provide a filler for the shell. and providing means for heating the metal shell and/or the filler material when energised.

The present invention in accordance with this further aspect may include any or all of the features described in the other aspects and embodiments of the invention to the extent that it is not mutually inconsistent therewith.

The support element of the invention in any of its aspects or embodiments may be used in any type of outdoor furniture. The present invention extends to the use of the support element in the assembly of outdoor furniture e.g.. an item of outdoor furniture.

The present invention extends to outdoor furniture e.g. an item of outdoor furniture comprising one or more support element in accordance with the invention in any of its aspects or embodiments. The outdoor furniture preferably comprises a plurality of the support elements. The or each support element may be arranged to provide support to a user of the outdoor furniture or to an object supported by the furniture.

The outdoor furniture may comprise one or more support portion for supporting a user or object, at least one, or preferably each such support portion comprising one or more of the support elements. For example, a support portion may be a seat portion or back portion of a seat e.g. bench as discussed below, or could be a support portion of a table etc. The or each support element in accordance with the invention is arranged such that heat may be transmitted to a user of the furniture e.g. via a first surface of the element. While some preferred embodiments will be discussed in relation to support portion(s) in the form of a seat or back portion of a seat e.g. bench, it will be appreciated that any other support portion of the outdoor furniture may be of the construction described in relation to the seat or back portion below.

Preferably the outdoor furniture is a seat, and most preferably a bench. The seat may comprise a seat portion and optionally a back portion. The seat portion is the portion on which the user sits i.e. which supports the legs of a user. The back portion supports the back of a user. At least one, and preferably each of the seat and back portions (where provided) comprises one or more of the support element(s) of the present invention in any of its embodiments. Preferably at least the seat portion comprises one or more of the support element(s). Thus, the seat may comprise a seat portion and/or a back portion that includes one or more of the support element(s). The or each portion may be defined by the one or more support element(s). Either one of the seat or back portion, or both the seat and back portion may comprise, or be defined by a single such element, or a plurality of the support elements. The or each support element in accordance with the invention is arranged such that heat may be transmitted to a user of the seat e.g. via a first surface of the element. For example, in some preferred embodiments the seat and back portions of the seat e.g. bench may each comprise a single one of the elements, or, where the seat e.g. bench does not include a back portion, the seat e.g. bench may include a single support element. References to a portion including or comprising a single support element of the invention refer to there being only one such support element in the relevant portion, ft is also envisaged that one or more of the heated support elements of the invention may be combined with one or more support element that does not include heating means e.g. with a seat portion comprising one or more support element of the invention and a back portion that includes one or more alternative support elements, or vice versa, or in which a given one of the back or seat portion includes a mixture of one or more support element of the invention and another type of support element.

The or each support element may extend the entire length or width of the seat or back portion, ft is envisaged that multiple support elements may be arranged side-by-side, or end to end in a seat or back portion. Preferably the or each support element extends the entire length of the seat or back portion. Where a back or seat portion includes only a single support element, the support element may define the back or seat portion. The length and width of the seat or back portion may correspond to the length and width of the element. The above possibilities apply equally to any other support portion which may comprise one or more support elements.

Where furniture includes multiple support elements, these may be of the same or different construction.

Of course, other types of furniture may be envisaged e.g. tables etc. A seat may be in the form of a chair for a single user rather than a bench for multiple users. Seats may be used in any outdoor environment e.g. outside a pub or restaurant, at a stadium etc. An outdoor environment or location may be a fully outdoor or semi outdoor environment or location, e.g. where some shelter is provided.

The furniture is preferably a standalone item of furniture i.e. a freestanding item of furniture, such as a bench. Here the advantages in terms of providing a lightweight, easy to construct item of furniture are particularly useful. The furniture may provide a unit of outdoor furniture. The furniture may be furniture that is movable from one location to another. However, the invention may also be apphed to furniture e g. a bench that forms part of an integrated structure e.g. in a stadium.

The outdoor furniture may further comprise means for connecting the furniture to a power supply for energising the heating means of the or each support element. The power supply is preferably an electrical power supply for providing electrical energy to the heating means. Such means for connecting the furniture to a power supply may comprise one or more wires etc. The furniture may comprise means for earthing the metal shell of the or each support element as described above, and/or one or more other electrical safety features e g. to comply with relevant regulations.

The invention extends to the use of the heated outdoor furniture, comprising energising the heating means to heat the furniture.

The outdoor furniture preferably further comprises a frame. The frame may be a metal frame. The frame may retain the or each support element in the assembled configuration of an item of outdoor furniture. Any other type of supportive element may alternatively be used.

The method of the present invention may comprise the steps of assembling one or more of the support elements to provide outdoor furniture e g. an item of outdoor furniture. The present invention may therefore provide a method of providing outdoor furniture comprising assembling one or more support elements obtained in accordance with any of the embodiments of the method described herein to provide the outdoor furniture. The outdoor furniture may be in accordance with any of the above described embodiments. The method may comprise combining the one or more support elements with a frame to provide the outdoor furniture. It will be appreciated that the support elements may be manufactured in one location, with assembly to form the outdoor furniture occurring elsewhere. As the support elements may be lighter than prior art e.g. beams, transport to an assembly location may be facilitated and may be achieved at less cost. This may also provide greater convenience avoiding the need to carry out casting at or near a location where an element is intended to be used.

The present invention extends to a step of installing the outdoor furniture in an outdoor location.

The present invention extends to a kit of parts for an item of heated outdoor furniture comprising one or more of the support elements in accordance with any of the embodiments of the invention (and preferably a plurality thereof), and optionally a frame e.g. a metal frame.

In accordance with any of the aspects or embodiments of the invention, the outdoor furniture may comprise control means for controlling the heating of the furniture. The control means may be arranged to control the heating of the furniture in response to manual input and/or automatically. The control means may comprise a set of one or more processors. The control means may be arranged to control the heating of the furniture in response to one or more received signals transmitted thereto e.g. by a remote processing unit. The transmission is preferably a wireless transmission. Alternatively the control means may be arranged to control the heating of the furniture in response to local input. The control means may be arranged to control a temperature to which the or each support element is heated, and/or a time or times of operation of the heating means. For example, the control means may arrange for the heating means to be energised at one or more predetermined times e.g. in the evenings, or in response to environmental conditions e.g. a temperature of the environment falling below a given threshold. The control means may receive data indicative of a sensed temperature of the environment from a remote processing unit, or the furniture may comprise one or more temperature sensors for detecting a temperature of the environment.

The furniture may comprise one or more temperature sensor for detecting a temperature of a heated portion of the furniture i.e. of a portion of a support element thereof. The control means may control the temperature of the furniture based upon the detected temperature. It is envisaged that temperature sensors may be associated with each heated support element of the furniture. For example, a temperature sensor may be provided for detecting a temperature of the metal shell e.g. being located in thermal contact with an interior or exterior heated surface thereof. The temperature sensor may be arranged to detect a temperature of the user or object supporting surface of the support element.

It will be appreciated that the term "layer" used herein e.g. in relation to concrete does not imply any particular depth or configuration for the layer, or that any further layers of any type are present. A concrete layer may be provided by any body of concrete material. Any reference to a concrete layer herein may be replaced by a reference to a concrete body.

The present invention in accordance with any of the further aspects or embodiments may incorporate any of the features described in relation to the other aspects to the extent they are not mutually exclusive.

Some preferred embodiments of the invention will now be described by way of example only, and with reference to any one of the accompanying drawings of which;

Figure 1 shows a heated bench incorporating two support elements in the form of beams in accordance with the present invention;

Figure 2 is a transverse cross sectional view of a support element in the form of a beam in accordance with one embodiment of the invention;

Figure 3 is a transverse cross sectional view of a support element in the form of a beam in accordance with an alternative embodiment of the invention;

Figure 4 is a transverse cross sectional view of a metal shell having ribs which may be used in accordance with the invention;

Figure 5 is a perspective view of the interior of the shell of Figure 4 from above;

Figure 6 is a perspective view of the shell of Figures 4 and 5 from below;

Figure 7 is a longitudinal cross sectional view of an advantageous rib which may be used in the embodiment of Figures 4-6;

Figure 8 shows a transverse cross-section of a further embodiment of a beam in accordance with the present invention;

Figure 9 is an exploded perspective view of the interior of the shell of the beam of Figure 8; and Figure 10 illustrates an alternative shaped item of outdoor furniture in accordance with the invention.

Figure 1 shows a heated outdoor bench 10 having two identical support elements in the form of beams 12 in accordance with the present invention. One beam 12 forms a seat portion of the bench. The other beam 12 forms a back portion of the bench. The beams 12 are connected by a metal frame 14 to form the bench 10. The bench 10 also comprises wires (not shown) for connecting the bench to an electrical power supply for energising the heating means of the beams. In one exemplary embodiment, each beam 12 has a length LB of 1.5m, a width WB of 0.36 m and a thickness TB of 5.6cm. Of course, the dimensions of the beams may be varied as required for a given application, and where multiple beams are used, these may be of differing dimensions.

When connected to a power supply, the heating means of the beams may be heated to enable the user or object facing surfaces thereof to be heated to a desired temperature. The bench may comprise control means (not shown) for regulating the temperature of heating and/or the timing of operation of the heating means, and also providing any necessary safety features e.g. to cut off the power supply in the event of a fault. Operation and/or temperature of heating may be in response to environmental conditions. Suitable temperature sensor(s) may be provided to enable thermostatic control of heating. The control means may be responsive to control signals received wirelessly from a remote processor. By way of example, the heating means may be operative to heat the user facing surface(s) of the beam including the heating means to a temperature in the order of 42-45 degrees Celsius, which has been found to provide good user comfort in an outdoor bench. It is envisaged that the user facing surface(s) of a beam forming a back portion of a bench may be heated to a higher temperature than those forming a seat portion thereof, e.g. around 50 degrees Celsius, due to the reduced contact pressure that might be expected with the user. Such temperature ranges are applicable equally in embodiments in which aseparate heating element is used, or in which a current is applied to electrically conductive concrete layer as described below.

Figure 2 shows a transverse cross-section of an embodiment of a beam 12 in accordance with the present invention, and which may be used in the Figure 1 embodiment. The beam 12 comprises a first concrete layer 14 and a second concrete layer 16 in a metal shell 18. The beam 12 has a first surface 22 and a second surface 24. The first surface 22 is intended to face a user in use. In use, the first surface 22 is heated by the heating means via the first concrete layer 14 and the metal shell 18, whilst the second surface 24 is thermally insulated by the second concrete layer 16. The metal shell 18 extends around the first and second concrete layers 14, 16 with an open end 26 proximate to a portion of the second concrete layer 16.

The heating means for the first concrete layer 14 has been embedded in the first concrete layer 14. The heating means for the first concrete layer 14 comprises a heating cable 20, which extends along the length of the layer in a serpentine manner. The first concrete layer 14 comprises a synthetic graphite aggregate material which results in a low density concrete layer which, thus, is light-weight. The first concrete layer may have a density of less than 2000Kg/m3. It also has good thermal conductivity properties (and electrical conductivity properties, which are exploited in the further embodiment of Figure 3). One suitable material is Marconite®. The second concrete layer 16 comprises a clay-based aggregate material, which provides the layer with good thermally insulative properties (and also electrical insulative properties as exploited in the embodiment of Figure 3). This prevents heat from escaping through the second surface 24, thus providing a more energy efficient beam.

It will be appreciated that it is only preferred to provide a second concrete layer as shown in Figure 2. The second concrete layer could be replaced with an alternative thermally insulating layer, suitable alternatives including an insulating foam such as a polyurethane foam or an insulating board. One exemplary insulating board is formed of an extruded polystyrene foam core coated with cement mortar to provide a rigid board. A suitable such board is the Marmox™ board. The thermally insulating layer may be located between the first concrete layer 14 and the second surface 24 of the beam 12. Alternatively a thermally insulating material e.g. a polyurethane foam or insulating board might be embedded within the first concrete layer 14. The use of a thermally insulating second concrete layer is advantageous as this may extend continuously over the entire surface of the first concrete layer to maximise thermal insulative effect.

During manufacture, the metal shell 18 is placed with the surface that provides the first surface 22 of the beam facing down, such that the open end 26 is facing upwards. The heating cable 20 is located within the metal shell 18. A first concrete mix for forming the first concrete layer 14 is poured into the metal shell 18, and covers the heating cable 20. The first concrete mix is then left to at least partially set. For example, it may be left for 1-2 hours. A second concrete mix for forming the second concrete layer 16 is then poured into the metal shell 18 on top of the first (at least partially set) concrete layer 14. Both concrete layers 14, 16 are then left to fully set, for example for 12 hours. The beam 12 can then be assembled with other beams and metal frame to form outdoor furniture such as the bench 10 of Figure 1. This may take place at a different time and location. Thus, the metal shell forms a mould for the concrete layers, and remains an integral part of the finished beam. Where no second concrete layer is to be provided, the method may instead involve locating a suitable thermally insulating layer on top of the first concrete layer once set, or providing thermally insulative material within the layer before it sets. Figure 3 shows a transverse cross section of an alternative embodiment of a beam 12 in accordance with the present invention, and which may also be used in the embodiment of Figure 1. The element 12 is the same as that of Figure 2, except that a different heating means is used. Two electrodes 28 are located in the first concrete layer 14, towards the longitudinal edges thereof, i.e. extending along the length of the beam 12. The first concrete layer 14 is formed from a concrete having good electrical conductivity properties. This concrete layer may comprise a synthetic graphite aggregate material, as exemplified for the first concrete layer in the embodiment of Figure 2. Such a material may also impart the layer with electrical conductivity properties, as well as good thermal conductivity.

The ingredients of the first concrete layer 14, and the ratios thereof, may be selected as appropriate to achieve a desired level of electrical conductivity, or conversely resistance, for the layer in this embodiment. For example, additional electrically conductive material e.g. iron or steel powder or filings may be included in the layer. The electrical resistance of the layer may be customised by selecting the ratio of cement or standard silica aggregate material to the other components appropriately. When the electrodes are energised, a current passes through a portion 30 of the first concrete layer 14, which directly heats it. The concrete material acts as a resistive heating element. By way of example, in the context of providing a beam for a bench, it has been found that by creating an integral resistive heating element in the concrete with a resistance of approximately 100 ohms, when powered with a 240V (mains) supply, approximately 600W of power is used by the element, which gives both a good heat up time and ability to maintain a desirable temperature even in very cold ambient air temperatures. A synthetic graphite aggregate material that has been found to be useful has a resistivity of 0.001 Ohm/m. In alternative embodiments, the two electrodes 28 may be located along the lateral edges of the beam, i.e. extending along the width of the beam. In yet another alternative embodiment, the heating means may comprise a set of electrodes having a single charged electrode located between two oppositely charged or neutral electrodes. The oppositely charged or neutral electrodes may advantageously be located along the edges of the beam as in the embodiments using pairs of electrodes. In yet other embodiments, multiple sets of electrodes (whether including two or three electrodes) are provided for applying current to multiple discrete portions of the concrete layer e.g. with sets of electrodes being located along the longitudinal or lateral edges of the layer.

In the embodiment of Figure 3, the beam further comprises an electrically insulating coating (not shown) between the first concrete layer 14 and the metal shell. This coating is applied to the inner surface of the metal shell before the first concrete is poured into it. The coating is suitably thin to minimise any impact on thermal conduction of heat from the concrete layer to the shell. The coating material may be a powder paint or an epoxy. The metal shell 18 is also earthed (not shown) to comply with safety regulations. This is preferably achieved independently of the electrically insulative coating, e.g. by using an electrical earth in a control box that will trip a fuse or RCD or similar, in the event the insulative coating were to fail and the metal shell became electrically live. Suitable arrangements may be provided to comply with apphcable safety regulations. The second concrete layer, which is identical to that of Figure 2, may additionally act to provide electrical insulation on the other side of the first concrete layer. Of course, the second concrete layer may, as with the earlier embodiment, be omitted, and replaced by an alternative suitable thermally and electrically insulative layer.

The embodiment of Figure 3 may be manufactured in the same manner as that of Figure 2, by sequentially pouring the first and second concrete mixes into the shell. The electrodes may be located in the shell before the first concrete mix is added.

The concrete mixes for either of the first or second concrete layers used in the embodiments of Figures 2 or 3 may include additives to help tailor the viscosity of the concrete e.g. to a allow a lower ratio of water to cement to be achieved in the mix while maintaining low viscosity to aid pouring of the concrete. Suitable such additives include the liquid additives discussed earlier. In accordance with any of the embodiments of the invention, a cover, such as a backplate, may be mounted over the open end of the metal shell, so that the second concrete layer (or any other electrically insulative layer facing the opening in the metal shell) is not exposed. The backplate will then define at least a part of the second surface 24. This may provide a more attractive finish. The backplate may be a metal plate e.g. a steel plate. The method may include a step of adding such a backplate. The embodiment of Figure 1 shows beams which include such a backplate. It will be appreciated that the need to provide a cover e.g. backplate is less for the beam providing the seat portion, whose reverse side is less visible to a user.

The thickness of the or each concrete layer may be selected as desired. By way of example only, in the embodiments of Figures 2 or 3, the thickness of the first concrete layer TCI including a separate heating element might be in the order of 20-28mm. The thickness of the second concrete layer TC2 might be in the order of 28-36 mm. In the embodiment of Figure 3, the thickness of the first concrete layer TCI,which does not include a separate heating element, may be slightly less e.g. in the order of 20-25mm, with the thickness of the second concrete layer TC2 remaining the same i.e. in the order of 28-36mm. Where the second concrete layer is replaced by a nonconcrete thermally insulating layer e.g. a board, such a board may have a thickness of e.g. 10 mm. Such ranges have been found to be useful in the context of beams for a bench, providing a suitably lightweight beam. In general, the minimum thickness for a concrete layer may depend upon the thickness of the largest aggregate particles in the mix. It has been found that the minimum thickness of the layer is desirably just over twice the diameter of the largest aggregate particle in the mix. For example, where the largest aggregate particles used are of 5-6 mm diameter (which has been found to be a useful size in one exemplary embodiment), this may lead to a thinnest layer of around 12-14mm.

It will be appreciated that the above ranges are provided only for the purposes of illustration, and the thicknesses of the layers, their relative thicknesses, and the size of aggregate particles used may vary widely depending upon e.g. the desired application and properties of the support element, as well as the desired properties of the support element e.g. any constraints on weight, dimension etc. In general, the thickness of the second (insulating) concrete layer may be greater than that of the first (heated) concrete layer, although this need not be the case. The thickness of a concrete layer heated using a separate heating element may be greater than that using integral heating in order to accommodate the heating element.

The construction of a metal shell which is used in accordance with preferred embodiments, and which may be used in any of the earlier embodiments, will now be described.

Figure 4 shows a transverse cross sectional view of a metal shell 18 which may be used in obtaining a support element in accordance with the invention in the form of a beam 12, and which may be used in any of the earlier described embodiments. Ribs 32 are provided which extend from the interior of the first surface 23 of the main body of the shell (which provides the bottom of the shell when used as a mould), and are perpendicular thereto. The main body has side portions 27 and a rim 25 surrounding an opening 26 at an end opposite that which defines the bottom of the mould in use. The ribs 32 extend the length of the shell. The ribs 32 reinforce the shell 18, giving it additional rigidity, and also give the concrete something to bind to. The ribs might be formed of steel e.g. mild or stainless steel.

Figure 5 is a perspective side view of the metal shell 18 of Figure 4 from above the interior surface thereof. The main body of the metal shell 18 has been formed from one blank of material, and separate ribs 32 attached thereto. The blank has been folded to form bottom 23 and side 27 portions, and the rim 25, leaving an open end 26. In use the bottom or first surface 23 of the shell defines the first surface 22 of the beam, while the rim 25 provides a portion of the second surface 24 of the beam.. The steel ribs 32 can be adhered or welded to the blank.

Figure 6 shows a perspective view of the metal shell of Figures 4 and 5 from the underside of the interior surface, showing the ribs 32 extending the length of the main body of the shell.

Rather than being formed of a single piece of material, the main body of the metal shell may be provided in more than one part. For example, the main body may include an intermediate portion and a pair of end caps that define the longitudinal ends thereof. The end caps may be welded to the intermediate portion, and may be made of the same material e.g. steel.

Figure 7 shows one embodiment of an advantageous rib 32 suitable for use in the present invention in longitudinal cross section. The rib 32 includes holes 34. This enables setting concrete to form a pillar through each hole, securely binding the concrete to the metal shell 18. The number and spacing of the holes may be selected as desired.

Where provided, ribs may have any suitable height. For example, a height of at least 10mm has been found to be appropriate. The height of the rib may be balanced with other factors e.g. the configuration of openings in the rib through which concrete may flow, to ensure adequate bonding to a concrete layer. A rib may have the same height as the concrete layer e.g. first concrete layer to which it is bonded.

In an exemplary embodiment for use with a beam for inclusion in a bench e.g. as shown in Figure 1, and having a length of 1.5m, the ribs have a length LR of 1.5m and a height HR of 1.5 cm, and the centre of each of the holes 34 is located a distance a= 0.75 cm from each of the top and bottom edges 36 of the rib 32. The first holes along the rib are located a distance a distance b= 10 cm from each end edge 38 of the rib 32. Additional holes, not shown in Figure 7 are located at intervals of 10cm (centre to centre) along the rib between those holes shown. The holes 34 have a diameter of 5 mm. The ribs may have a thickness of 3mm. In some exemplary embodiments in which the beam has a width of 35.6 cm, three such longitudinal ribs may be provided, spaced at approximately equal intervals across the width of the beam. Of course, other arrangements may be used. The general construction of the rib, including holes as shown in Figure 7, may be used in combination with any desired set of dimensions, and arrangement e.g. number and spacing of holes, etc. The configuration of the ribs may be selected as desired to provide bonding to a concrete layer.

Figure 8 shows a transverse cross-section of a support element in the form of a beam 12 in accordance with a further embodiment of the present invention, and which may be used in the Figure 1 embodiment. Like reference numerals have been used for like components present in the earlier embodiments. The beam 12 comprises a flexible heating panel in the form of a heating mat 15 and a thermally insulating layer 16 in the metal shell 18. Beam 12 has a first surface 22 and a second surface 24. The first surface is intended to face a user in use. In use, the first surface 22 is heated by the heating mat 15, whilst the second surface 24 is insulated by the thermally insulating layer 16.

The metal shell 18 extends around the insulating layer 16, with an open end proximate to a portion of the insulating layer 16. The open end is covered by a backplate 26. An example of a suitable heating mat 15 is a silicone rubber heating mat. Such heating mats are known in the art, and may have wire wound or etched foil heating elements.

For example, one exemplary mat may contain a single resistive wire that is contained in a thin, roughly 3mm thick silicone sheet, and has a self-adhesive backing. It will be appreciated that the heating panel need not be in the form of a heating mat, and need not be flexible. For example, a non-flexible heating panel may be provided that has a shape conforming to the inner surface of the shell e g. a flat heating panel.

The heating mat 15 is located between the insulating layer 16 and the metal shell 18 adjacent the first surface 22. Electrical cable 17 extends from heating mat 15 for connection to a power source. Thermostatic control line 19, which also extends from the heating mat 15 may provide temperature data to a controller associated with the furniture when the beam is incorporated in an item of furniture in use to allow thermostatic control of the temperature of the heating mat 15. The controller may be of the type described in relation to the earlier embodiments.

The thermally insulating layer 16 is a thermally insulating foam layer, preferably a polyurethane foam layer. Figure 8 illustrates schematically the cavities in the foam. The foam is an expanded rigid closed cell foam formed by a liquid foam material that has expanded and set in the shell. The use of the thermally insulating layer 16 provided in this manner is advantageous as this may extend continuously over the entire surface of the heating mat 15 to maximise thermal insulative effect thereof. An expanded thermally insulating layer is particularly advantageous as the material may expand to fill the shell. However, it is envisaged that other types of thermally insulating filler material may be used, which may or may not be a foam material and/or have expanded in the shell.

Figure 9 is an exploded perspective view of the interior of the shell of Figure 8. The metal shell 18 is the same shape as in previous embodiments, i.e. those of Figures 2 and 3, but does not include ribs. Backplate 26 includes a set of holes 21, which may be used for various purposes e.g. in mounting the support element and/or providing electrical or other connections to the support element. Although four holes are shown, a different number may be used as required. Some of the holes may be used for mounting the beam to a frame or other supportive surface when used to construct an item of outdoor furniture. As illustrated, the electrical cable 17 and thermostatic control line 19 may extend through one of the holes to reach the exterior of the beam, leaving four holes for mounting purposes. Of course, the cable and controlline need not extend through the same hole, and a differing arrangement of holes may be used depending upon how mouting is to be achieved (mounting holes may not even be required). One of the ends 42 of the metal shell 18 includes two holes 40 for use in the introduction of the expandable liquid foam material, which provides the expanded foam thermally insulating layer, as will be discussed below.

During manufacture, heating mat 15 is located within the metal shell 18, being adhesively attached to the interior surface of the shell, and backplate 26 welded thereto to cover the opening in the shell. An electrical connection is formed between the heating mat 15 and the outside of the metal shell 18, by running electrical cable 17 through a hole 21 in the backplate. The thermostatic control line 19 also passes through its respective hole. The thermally insulating foam is formed from an expandable liquid foam material that expands in the shell. The expandable liquid foam material is provided by mixing two components, manually, or using an appropriate machine, in a prescribed ratio to provide the expandable liquid foam material. Suitable two component expandable foam materials are known in the art. The expandable liquid foam material is then introduced through the holes 40 into the shell. The mixing may occur during introduction of the material to the shell e.g. in an appropriate mixing means associated with a delivery device, or may be carried out earlier e.g. manually. The other hole 40 vents the expanding foam material to allow the escape of air during introduction of the expandable foam material, preventing air pockets being trapped in the resulting foam structure.

It has been found that it may be advantageous to orientate the metal shell 18 vertically with the end 25 including the two holes 40 facing upwards before introducing the expandable liquid foam material. However, the position of the holes 40 need not be as shown, and these may be located in a different portion of the metal shell 18 or the back plate 26. Of course, the expandable foam material need not be introduced through respective holes in this way. However, the material is introduced, it is desirable for the liquid foam material to be introduced through a highest point of the shell at that time to reduce the likelihood of air pockets being trapped in the foam. It will also be appreciated that the liquid foam material provided in the shell need not be provided from a two component mixture, although this has been found to provide greater control over the expansion process. Similarly, the components may be mixed in the shell after being introduced thereto, although mixing before or during introduction to the shell is preferred to provide greater control over the mixing of the components, and hence more reliable expansion.

Once the components of the expandable liquid foam material have been mixed, there is typically a small delay e.g. 40 seconds or so, before expansion begins, during which time the material may be introduced into the shell. It will be appreciated that the mixture of the components which provides the expandable liquid foam (or other filler material) is referred to herein as the expandable liquid filler/foam material, even if expansion has not yet commenced.

The foam can be formed from a single quantity of liquid foam material, or in stages, i.e. a first smaller quantity of expandable liquid foam material that is introduced to the shell and which expands and solidifies before a further quantity of the expandable liquid foam material is introduced into the metal shell 18 to expand and solidify. This process may be repeated multiple times until the metal shell 18 is filled with the expanded foam material to a desired extent. Different quantities may be introduced through different ones of the holes 40. The shell may be manipulated to change its position between additions of quantities of material, to promote even filling. This is optional, although particularly useful for more complex shell shapes. Desirably each quantity of liquid foam material is introduced through a highest point of the shell at that time. A cover or covers e.g. an endplate (not shown) may then be welded over the holes 40 in the end of the shell. The metal shell 18, back plate 15, and end plate may be formed from the same material, having the same thickness.

The beam can then be assembled with other beams and a metal frame to form outdoor furniture such as the bench 10 of Figure 1. This may take place at a different time and location.

It will be appreciated that the use of a heat pad, or other flexible heating panel, enables support elements in a wide range of shapes and sizes to be produced, not limited to those shown in the form of a beam of the type shown in Figures 8 and 9. For example, a shell may be produced that has curved portions, or indeed of any free form shape. The expandable foam material may expand to fill any shape of shell. Any other expandable filler material may equally create a suitable body of thermally insulating material to fill a shell of given shape. A single shell may be provided that includes seat and back portions. An item of furniture may then be produced using a single such support element. The furniture may not need a frame. The flexible heating panel will conform to the user-facing surface of such support elements. Of course, while a flexible heating panel is particularly convenient, non-flexible heating panels may be used, of an appropriate shape to conform to the interior surface of the shell, e g. that have been shaped to include a curved portion etc.

One example of an item of furniture incorporating an alternative shaped support element is illustrated in Figure 10. Figure 10 is a transverse cross section through the furniture. The furniture is a bench 50, that includes a support 52 and a support element 54 in accordance with the embodiment of Figures 8 and 9. The support element 54 includes a shell 56 that has been shaped to provide both the seat and back portions of the bench. First and second heat mats 58,60 are associated with the interior of the shell defining the seat and back portions respectively. The shell is filled with an expanded foam filler material 62.

It will be appreciated that a heating panel, preferably a flexible heating panel, such as a heat pad, as used in the embodiment of Figures 8 and 9, may equally be used in the earlier Figure 2 embodiment instead of a heating cable. This provides the advantage that the concrete layer may be made thinner, as it does not need to have a thickness to result in a heating cable being embedded therein.

Conversely, the embodiment of Figures 8 and 9 (or 10) may optionally also contain a (thin) concrete layer (not shown) between the heating mat 15 and the interior of the shell 18 to aid in the distribution and storage of heat. The heating mat 15 may then be sandwiched between the concrete layer and the thermally insulating layer. The heating mat 15 may be adhesively attached to the side of the concrete layer closer to the second surface 24 of the beam i.e. the non heated surface.

Support elements that do not include a concrete layer, or at least only a thin concrete layer, can be thinner than those of previous embodiments, as the combination of the heating panel e.g. heat mat 15, the insulation layer 16 and the sides of the metal shell 18 have a smaller minimum possible thickness than embodiments including, for example, concrete having a heating cable therein, i.e. Figure 2. The heating cables used in Figure 2 are typically at minimum about 17mm thick and, thus, the concrete must be at least this thick in order for the cables to be embedded therein. The thickness of a heating mat, in contrast, may be, for example, in the order of 3 mm. Thus, even if a thin layer of concrete is used in addition to the insulation layer, this embodiment has a smaller potential minimum thickness than one including a heating cable embedded in concrete.

The present invention may provide relatively lightweight support elements. By way of example, it has been found that a beam made in accordance with the Figure 2 embodiment, i.e. including a separate resistive heating element, and using a 10mm thick insulating board rather than a second concrete layer as illustrated in Figure 2, may have a weight in the region of 35-70 Kg, such as 60-65 Kg. Further, a beam made in accordance with the Figure 8 embodiment, which does not require a concrete layer, may have a weight in the region of 15kg, such as roughly 10-20kg. This reduces shipping costs, provides for easier handling for installation and simpler compliance for health and safety when being move or in transit. It also opens up more markets where portable applications are required. For example, such beams may be used to build outdoor furniture for use in private homes and gardens, where it is desirable to be able to easily move the furniture. Furniture built from heavier beams, for example those of Figure 2, may be desirable for other applications, such as in pubs and bars wherein it is desirable that the furniture is not moved.

Along with providing an impact on weight, the presence of a concrete layer also affects the thermal properties of the beam. The concrete used (in the heated concrete layer), as discussed with respect to earlier embodiments, may be chosen to be a relatively good conductor of heat compared to other concretes. However, it will naturally be a less good conductor of heat than the metal shell. Therefore, when the heat is provided to the concrete layer, it can take approximately 20-50 minutes, depending on the thickness of the concrete layer and the concrete used, for the beam to heat up to the desired temperature, because the concrete has a high specific heat capacity. Due to this, once power is no longer supplied to the heating means, the beam will remain warm or hot for a longer period of time, i.e. it will cool down slower than in embodiments wherein less or no concrete is used. In contrast a concrete free support element may heat up in less than 1 minute. Thus there is a trade-off between the delay in the beam heating, and the length of time the beam retains the heat. The ideal is different for different intended applications of the beam and, as such, the amount of concrete used can be adjusted accordingly.

It will be appreciated that the thickness of the thermally insulating layer/material may be selected as desired to reduce heat loss through the applicable side(s) of the support element, with a thicker layer or body of material increasing energy efficiency of the beam and the rate at which the element heats up. In embodiments including both a concrete layer and a thermally insulating layer, the relative thicknesses of the layers may be balanced appropriately, with a greater relative thickness of thermally insulating material increasing thermal efficiency, and increasing the rate of heating, while, where a non concrete thermally insulating material is used, reducing the overall weight of the support element, as the density of the thermally insulating material is typically less than that of concrete. The presence of the metal shell opens up the possibility to eliminate the use of concrete altogether, or at least use a thinner layer, as the concrete is not required to provide all of the tensile and compressive strength of the beam. Due to the presence of the metal shell, the concrete need not flow around a heating cable to maintain its inherent strength, and it is not necessary to use a heating cable embedded in the concrete layer (although such a cable may of course be used, depending upon the desired properties of the support element). As discussed above, this opens up the possibility of a greater range of layered constructions utilising different materials as desired to provide particular properties to the support element, while retaining the required strength for the support element.

Although the thickness of the metal shell may vary, and may be selected as desired, in some exemplary embodiments suitable for use with beams of the dimensions described above, a steel shell of 3 mm thickness has been used.

The above embodiments are merely exemplary. It will be appreciated that the support elements of the invention may be produced in a range of configurations and dimensions, and need not be in the form of the beams as illustrated. Furthermore, the number of such beams or support elements used in any particular item of outdoor furniture may vary. The support elements may be combined with conventional support elements which do not include heating means.

The outdoor furniture need not be in the form of a bench, or indeed a seat of any type. It will be appreciated that, depending upon the intended use of the furniture, a support element may be arranged to support an object in general, rather than a user. Any reference to a user facing or supporting surface or similar may be replaced by a reference to an object facing or supporting surface. For example, the furniture may be in the form of a table. However, preferably the support element is for supporting a user, and transmitting heat to the user.

Although the present invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope of the invention as set forth in the accompanying claims. Particularly, it will be appreciated that features described in relation to particular embodiments or for use in particular preferred applications may also be applied to other embodiments, except where these are mutually exclusive. For instance, any dimensions listed above are merely illustrative and whilst suitable for some preferred applications, the skilled person will appreciate that the relative dimensions of the various components can be changed as desired for a given application.

Claims (78)

Claims:

1. A support element for heated outdoor furniture, the support element comprising; a metal shell; a thermally insulating filler material located in the shell; and heating means for providing heat to the shell when energised in use, wherein the heating means is disposed between the thermally insulating filler material and an interior surface of the shell.

2. The support element of claim 1 wherein heating means comprises one or more heating panel.

3. The support element of claim 2 wherein the or each heating panel is a flexible heating panel, such as a heat mat.

4. The support element of claim 2 or claim 3 wherein the or each heating panel has a thickness of less than 5 mm.

5. The support element of any one of claims 2 to 4 wherein the or each heating panel is adhesively attached to the interior surface of the shell.

6. The support element of any one of claims 2 to 4 wherein a concrete layer is disposed between the one or more heating panels and the interior of the metal shell.

7. The support element of any one of claims 1 to 5 wherein the support element is free from concrete.

8. The support element of any preceding claim wherein the thermally insulating filler material is an expanded material, and the shell has acted as a mould for the material during expansion.

9. The support element of any preceding claim wherein the thermally insulating filler material is a foam material, such as a polyurethane foam material.

10. The support element of claim 8 or claim 9 wherein the foam material is a closed cell foam material.

11. The support element of any preceding claim wherein the support element comprises a first surface intended to face a user or object in use to provide support to the user or object and through which surface heat may be transmitted to the user or object, and an opposite second surface intended to face away from the user or object in use.

12. A support element for heated outdoor furniture, the support element comprising: a concrete layer and means for heating the concrete layer when energised in use; wherein the support element further comprises a metal shell, the concrete layer being located in the metal shell.

13. The support element of claim 12 wherein the concrete layer has been cast in the metal shell, the metal shell having acted as a mould for the concrete layer during casting thereof.

14. A support element for heated outdoor furniture, the support element comprising: a concrete layer and means for heating the concrete layer when energised in use; wherein the support element further comprises a metal shell, wherein the concrete layer has been cast in the metal shell, the metal shell having acted as a mould for the concrete layer dining casting thereof.

15. The support element of any one of claims 12 to 14 wherein the concrete layer comprises a carbon based aggregate material, and preferably a graphite aggregate material, most preferably a synthetic graphite aggregate material.

16. The support element of any one of claims 12 to 15 wherein the concrete layer has a density of less than 2000 Kg/m3'

17. The support element of any one of claims 12 to 16 wherein the heating means is located at least partially within the concrete layer.

18. The support element of any one of claims 12 to 17 wherein the means for heating the concrete layer comprises at least one heating element associated with the concrete layer for providing heat to the concrete layer, wherein the at least one heating element is embedded in the concrete layer.

19. The support element of any one of claims 12 to 16 wherein the means for heating the concrete layer comprises one or more heating panels, preferably wherein the or each heating panel is a flexible heating panel.

20. The support element of any one of claims 12 to 16 wherein at least some of the concrete layer is electrically conductive, and the means for heating the concrete layer comprises means for passing an electrical current through one or more electrically conductive portion of the concrete layer in use to generate heat.

21. The support element of claim 20 wherein the support element comprises at least one set, and optionally a plurality of sets of two or more spaced electrodes, each set of electrodes being arranged to pass an electrical current through an electrically conductive portion of the concrete layer in use.

22. The support element of claim 21 wherein the or each set of spaced apart electrodes includes electrodes located at two opposing edges of the concrete layer.

23. The support element of claim 20, 21 or 22 wherein the concrete layer comprises a carbon based aggregate material to provide the concrete layer with electrical conductive properties, optionally wherein the concrete layer comprises a graphite aggregate material, most preferably a synthetic aggregate material.

24. The support element of any one of claims 12 to 23 wherein the support element comprises a first surface intended to face a user or object in use to provide support to the user or object and through which surface heat may be transmitted to the user or object, and an opposite second surface intended to face away from the user or object in use.

25. The support element of claim 24 wherein the element comprises a thermally insulating layer located on a side of the heating means toward the second surface of the support element.

26. The support element of claim 25 wherein the thermally insulating layer is located adjacent the concrete layer on a side of the concrete layer toward the second surface of the support element.

27. The support element of any one of claims 25 or 26 wherein the thermally insulating layer extends over the entire surface of the concrete layer and/or the thermally insulating layer is continuous over its surface.

28. The support element of claim 25, 26 or 27 as dependent upon claim 19 wherein the or each heating panel is sandwiched between the thermally insulating layer and the concrete layer, preferably wherein the thermally insulating layer is an expanded foam layer, such as a closed cell polyurethane foam layer.

29. The support element of any one of claims 25 to 28 wherein the thermally insulating layer is provided by a non-concrete material, such as a layer of polyurethane foam.

30. The support element of any one of claims 12 to 29 wherein the concrete layer is a first concrete layer, and the support element further comprises a second concrete layer located in the metal shell, wherein the second concrete layer is of a different type of concrete to the first concrete layer, and has at least one different property than the first concrete layer, optionally wherein the property is one or more of; thermal conductivity, electrical conductivity and density.

31. The support element of claim 30 wherein the second concrete layer is superposed on the first concrete layer.

32. The support element of claim 30 or 31 wherein second concrete layer comprises a clay-based aggregate material.

33. The support element of any one of claims 30 to 32 wherein the second concrete layer provides the thermally insulating layer of any one of claims 25 to 28.

34. The support element of any one of claims 30 to 33 wherein the second concrete layer has greater thermal insulating and/or electrical insulating properties than the first concrete layer.

35. The support element of any one of claims 12 to 34 wherein the support element comprises one or more ribs extending from an interior surface of a main body of the metal shell for contacting the or a concrete layer in the metal shell, optionally wherein the or each rib is a longitudinally extending rib.

36. The support element of claim 35 wherein the or each rib comprises one or more openings therethrough through which concrete of the concrete layer has flowed to create a concrete pillar facilitating bonding between the shell and the concrete layer.

37. The support element of any preceding claim wherein the support element comprises a cover over an opening of the metal shell.

38. The support element of any preceding claim wherein at least the main body of the metal shell is of steel or aluminium.

39. The support element of any preceding claim wherein the main body of the metal shell is a single piece main body.

40. The support element of any preceding claim wherein the support element is in the form of a beam.

41. A support element for heated outdoor furniture, the support element comprising; a metal shell; a filler material located in the shell; and means for heating the filler material and/or the metal shell to impart heat to the shell when energised in use.

42. Heated outdoor furniture comprising one or more support element in accordance with any preceding claim.

43. Heated outdoor furniture comprising at least one support element, the support element comprising: a layer of concrete and means for heating the concrete when energised in use; wherein at least some of the concrete layer is electrically conductive, and the means for heating the concrete layer comprises means for passing an electrical current through one or more electrically conductive portion of the concrete layer in use to generate heat in the concrete layer.

44. The outdoor furniture of claim 43 wherein the support element comprises at least one set, and optionally a plurality of sets of two or more spaced electrodes, each set of electrodes being arranged to pass an electrical current through an electrically conductive portion of the concrete layer in use.

45. The outdoor furniture of claim 44 wherein the or each set of spaced apart electrodes includes electrodes located at two opposing edges of the concrete layer.

46. The outdoor furniture of any one of claims 43, 44 or 45 wherein the concrete layer comprises a carbon based aggregate material to provide the concrete layer with electrical conductive properties, optionally wherein the concrete layer comprises a graphite aggregate material, most preferably a synthetic aggregate material.

47. The outdoor furniture of any one of claims 42 to 46 wherein the outdoor furniture is a seat, preferably a bench

48. The outdoor furniture of claim 47 wherein the bench comprises a seat portion comprising one or more of the support elements, and/or a back portion comprising one or more of the support elements.

49. A method of forming a support element for heated outdoor furniture in accordance with any one of claims 12 to 36, or claims 37 to 40 as dependent upon any one of claims 12 to 26; the method comprising: providing a metal shell shaped to act as a mould; providing a concrete mix in the metal shell; and allowing the concrete to set to form the concrete layer in the metal shell; wherein the method further comprises providing the means for heating the concrete layer when energised.

50. A method of forming a support element for heated outdoor furniture; the method comprising: providing a metal shell shaped to act as a mould; providing a concrete mix in the metal shell; and allowing the concrete mix to set to form a concrete layer in the metal shell; wherein the method further comprises providing means for heating the concrete layer when energised.

51. The use of the method of claim 50 in providing a support element in accordance with any one of claims 12 to 36, or claims 37 to 40 as dependent upon any one of claims 12 to 36.

52. The method of any one of claims 49 to 51 further comprising locating the heating means in the metal shell before the concrete mix forming the concrete layer is introduced thereto.

53. The method of any one of claims 49 to 51 wherein the step of providing the heating means comprises locating one or more heating panel on a surface of the concrete layer formed in the metal shell, preferably wherein the or each heating panel is a flexible heating panel.

54. A method of forming a support element for heated outdoor furniture in accordance with any one of claims 49 to 53, the method further comprising: providing an expandable liquid foam material in the metal shell, and allowing the foam material to expand and set in the shell to provide an expanded foam thermally insulating layer in the shell.

55. A method of forming a support element for heated outdoor furniture in accordance with any one of claims 1 to 11, or claims 37 to 40 as dependent upon any one of claims 1 to 11, the method comprising: providing a metal shell shaped to act as a mould; providing means for heating the metal shell when energised; providing a liquid fdler material in the metal shell, and allowing the filler material to set in the shell to provide a thermally insulating filler material in the shell.

56. A method of forming a support element for heated outdoor furniture, the method comprising: providing a metal shell shaped to act as a mould; providing means for heating the metal shell when energised; providing a liquid filler material in the metal shell, and allowing the filler material to set in the shell to provide a thermally insulating filler material in the shell.

57. The use of the method of claim 56 in providing a support element in accordance with any one of claims 12 to 36, or any one of claims 37 to 40 as dependent upon any one of claims 12 to 36, or the use of the method of claim 56 to provide a support element in accordance with any one of claims 1 to 11, or any one of claims 37 to 40 as dependent upon any one of claims 1 to 11.

58. The method of claim 55, 56 or 57 wherein the heating means comprises one or more heating panels arranged to provide heat to an interior surface of the shell

59. The method of claim 58 wherein the or each heating panel is a flexible heating panel.

60. The method of any one of claims 55 to 59 wherein the liquid filler material is an expandable liquid filler material, the method comprising allowing the expandable liquid filler material to expand and set in the shell to provide an expanded thermally insulating filler material in the shell.

61. The method of claim 54 or 60 wherein the expandable liquid filler material is the result of mixing first and second components.

62. The method of any one of claims 55 to 61 wherein the liquid filler material is a liquid foam material to provide a thermally insulating foam material in the shell.

63. The method of claim 54, claim 60, 61 or 62 wherein the method comprises building up the thermally insulating filler material in the shell in stages, by providing a quantity of expandable liquid filler material in the shell and allowing the material to expand and set in the shell, and providing a further quantity of expandable liquid filler material in the shell and allowing the further quantity of expandable liquid filler material to expand and set in the shell, and optionally repeating the steps of providing a quantity of expandable liquid filler material in the shell and allowing the material to expand and set in the shell for one or more further quantity of expandable liquid filler material.

64. The method of any one of claims 54 or 60 to 63 wherein the method comprises locating a cover over an opening in the metal shell before providing the expandable liquid filler material in the interior of the shell, wherein the metal shell and/or cover comprises one or more openings to permit the expandable liquid filler material to be introduced into the metal shell.

65. The method of claim 64 wherein a longitudinal end of the shell comprises one or more openings to permit the introduction of the expandable liquid filler material.

66. The method of any one of claims 64 or 65 wherein the method comprises moving the shell from a horizontal orientation to a vertical orientation for introduction of the expandable liquid filler material.

67. The method of any one of claims 54, or 60 to 66 further comprising the step of venting the expanding filler material to allow the escape of air.

68. The method of any one of claims 58 to 67 wherein the method comprises disposing the one or more heating panels in thermal contact with the interior of the metal shell, optionally wherein the method comprises adhesively attaching the or each heating panel to an interior surface of the shell.

69. A method of forming a support element for heated outdoor furniture, the method comprising: providing a metal shell shaped to act as a mould; providing a liquid filler material in the metal shell, and allowing the material to set in the shell to provide a filler for the shell; and providing means for heating the metal shell and/or the filler material when energised.

70. The method of any one of claims 49 to 52 wherein the concrete is electrically conductive, and the method further comprises providing an interior surface of the metal shell with an electrically insulating coating before providing the concrete mix therein.

71. The method of any one of claims 49 to 52 or 70 wherein the concrete mix comprises a carbon based aggregate material, such as a graphite aggregate material.

72. The method of any one of claims 49 to 52, 70 or 71 further comprising subsequently introducing a second, different type of concrete mix into the shell to provide a second concrete layer.

73. The method of claim 72 wherein the second concrete mix comprises a clay-based aggregate material.

74. A method of providing outdoor furniture comprising assembling one or more support elements obtained in accordance with the method of any one of claims 49 to 73 to provide the outdoor furniture.

75. The method of claim 74 comprising combining the one or more support elements with a frame to provide an item of outdoor furniture.

76. The method of claim 74 or 75 wherein the outdoor furniture is in accordance with any one of claims 42 to 48.

77. A kit of parts of providing an item of outdoor furniture comprising one or more support elements in accordance with any one of claims 1 to 41 and optionally a frame.

78. A support element, outdoor furniture or a method substantially as herein described and with reference to any one of the accompanying drawings.