The present invention relates to cladding panels (e.g. wall or roofing panels) and/or formwork panels. The panels are of the kind capable of being roll formed from a sheet metal. The invention extends to methods of joining those panels and to related structures, procedures and methodologies.

BACKGROUND ART

Long run cladding such as for roofing, walling etc. is frequently roll formed from a sheet of metal of appropriate thickness. Suitable materials include galvanised or coated steel or aluminium. Other metals can additionally be utilised. Complementary or similar forms may be provided in other materials (e.g. GRP as hereinafter discussed).

Many long run form panels have repetitive ridging features which are used to provide an attractive appearance and structural capacity whilst at the same time, in some instances, providing a point of contact with an underlying supporting clip attached to the pulins. In other forms it is simply an appropriate place where penetrative fixers such as headed screws can be passed through the panel or lapping panels so as to -ensure appropriate fixing with appropriate lapping top and bottom and side to side with complementary panels or fittings. Ridges are important also for appearance and structural strength. A typical difficulty with the design of long run roofing or roofing panels generally is the compromise that needs to be established between the thickness of the material and the costs that such a product can dictate. Another compromise is in respect of the usage of material in providing a spread of cover when one takes into account the losses of the breadth of a metal strip as a result of press or roll forming into ridged forms. For example, if a strip or band of sheet metal 1220mm wide is being roll formed with most of the conventional ridge forms and the edge lapping variations of such ridge forms, it is usual for such products at best to provide about 930mm cladding cover whilst at the same time still providing ridge buckling problems owing to point loading that may be occasioned by walking on the roof during its fixing or subsequently.

DISCLOSURE OF INVENTION

The present invention visualises a ridge form which lends itself for use in a roofing or walling panel which can enable a better coverage of roof or wall space by such a panel as against many, if not all, of the existing ridge forms. At the same time, or alternatively, the

present invention envisages a ridge form in roofing or walling panels formed from sheet material that has a greater resistance to point loading on the ridge form such that there is a greater tendency to resist crest deformation of any permanent kind.

As an alternative, or additionally, the invention is a lapping procedure to provide for panels with no need for wastage from the use of full ridge forms for the underlying lapped region.

As an alternative, a panel having any one or more of the foregoing characteristics, can be used as a formwork panel (e.g. for concrete flooring).

It is to such aspects the present invention is directed. In a first aspect the present invention consists in a roofing panel (or other panel) having at least one ridge or similar form provided therein, the ridge or similar form having substantially a trefoil arch type shape in section.

In another aspect the present invention consists in a walling panel (or other panel) having at least one ridge or similar form provided therein, the ridge or similar form having substantially a trefoil arch type shape in section.

In another aspect the present invention consists in a formwork panel (or other panel) having at least one ridge or similar form provided therein, the ridge or similar form having substantially a trefoil arch type shape in section.

As used herein "trefoil arch" refers generally to a substantially three lobed form typified by the trefoil arch of for example that of the trefoil arch bridge in Central Park, New York.

As used herein "trefoil" envisages any form preferably of a symmetric form, having three lobes whether each of a continuous curve or not. Preferably the central lobe extends outwardly from symmetric outer lobes. One, two or all of the lobes can be as if they were part of a curve such as the circumference of a circle or a near circle. Preferably the trefoil arch form is of a kind typified by that shown in the accompanying drawings and/or hereinafter described.

In a further aspect the present invention consists in a roll form panel or pressed panel having a plurality of ridge or similar forms formed therein, each of a shape typified by a trefoil arch as herein defined.

In a further aspect the present invention consists in a roll form walling, roofing or the like panel or pressed walling, roofing or the like panel having a plurality of ridge or similar forms formed therein, each of a shape typified by a trefoil arch as herein defined.

In a further aspect the present invention consists in a roll formed formwork panel or pressed formwork panel having a plurality of ridge or similar forms formed therein, each of a shape typified by a trefoil arch as herein defined.

Preferably such panels include variants of such an arch form at each side extremity such that one will nest on to the other.

Preferably the nesting capability is such that the overlying variant of the ridge includes a shoulder formed inwardly of the form (preferably at or adjacent the intersection of two lobes of the trefoil arch or part thereof), and the other extremity includes an edge, flange, lip, bead or the like adapted to fit onto such shoulder thereby conferring through such interaction a resistance to deformation of the coupled variants during any penetrative fixing thereof and/or during any point loading thereon.

The lapping variants may include formed therein localised indentation or indentations to break any capillary action between the nesting components.

Preferably the arrangement can be, by way of example, substantially as hereinafter described with reference to Figures 2 and 3 hereafter.

In yet a further aspect the present invention consists in a method of conferring improved resistance to plastic deformation of the crest of a ridge in a profiled panel formed from a sheet material, said method involving providing characteristics at least to some extent of a trefoil arch form to such a profiled panel. In yet a further aspect the present invention consists in a method of roofing which involves the use of panels in accordance with the present invention.

In yet a further aspect the present invention consists in a roof of panels in accordance with the present invention.

In yet a further aspect the present invention consists in a wall of panels in accordance with the present invention.

In yet a further aspect the present invention consists in a subfloor of panels or a concrete floor on panels in accordance with the present invention.

In yet a further aspect the present invention consists in panels substantially as herein described with reference to any one or more of the accompanying drawings. In yet a further aspect the present invention consists in a ridge form substantially as hereinafter described with reference to any one or more of the accompanying drawings.

As used herein "panel" is to restrictive to a purpose. It can include wall, roofing and other cladding.

BRIEF DESCRIPTION OF DRAWINGS

Preferred forms of the present invention will now be described with reference to the accompanying drawings in which

Figure 1 shows an end view of a first preferred roll formed (or pressed) panel in accordance with the present invention, there being two variants, each different, of the ridge profiles able to nest with the complementary edge of a like panel as hereinafter described.

Figure 2 is an enlarged view of the variant A and the full trefoil arch preferred ridge form depicted in Figure 1, there being minor ridge forms formed between the same for aesthetic and strength purposes, Figure 3 shows how the edge profile variant A can nest under the variant B of a like panel yet have its distal lip or flange supported on a shoulder formed as a variation of the (preferably trefoil) arch form otherwise depicted,

Figure 4 shows an end view of a panel (preferably a roofing panel but not necessarily so as it can be used for walling, floors, form work for floors, etc.), the embodiment showing but not being restricted to two complete inner ridges and peripheral ridge features to co-act in a lapping and mating manner,

Figure 5 is the other end view of the panel of any suitable length of Figure 4,

Figure 6 is a top view of a panel of Figures 4 and 5,

Figure 7 is a bottom view of a panel of Figures 4 to 6, Figure 8 is a side view of a panel of Figures 4 to 7,

Figure 9 is the other side view of the panel of Figure 8, and

Figure 10 shows an isometric view or perspective view of a panel of Figures 4 to 9, the panel being roll formed or press formed to any desired length.

In the preferred form of the present invention the panel is roll formed from a sheet steel whether pre-coated or not. In other forms it can be of another metal form. The choice of material is to be determined by its usage e.g. as exterior surfacing of a roof, wall or the like or whether as formwork (e.g. underlying formwork of a concrete floor).

A roof panel, for instance, may also be moulded in, for example, glass reinforced polyester material, and will have the same benefits of coverage and strength. GRP is used to manufacture skylight panels in the same profile shape as our metal roofing panels.

The main trefoil arch type profile of the ridge is shown as 1 and this has parts 2 and 3 which form flanking lobes to a main highest lobe 4. Preferably there is a transition that is a smooth curve or a fold line between the curves 2 and 4 and 4 and 3.

Localised variations in the curve of each lobe can be accommodated i.e. for example each curve can be a progression of folds such that it is a faceted curve. Likewise the transitions.

As shown the curves 2 and 3 do not necessarily have to form part of the circumference of a common notional circle but can instead be curves of any particular shape that complement each other and blend into the curvature of the central lobe. The central lobe as shown can have a notional diameter at variance to that of any notional radius of the curves

2 and 3.

As shown the panel preferably has a repeat at least twice of the form 1 across the expanse of the panel yet at each extremity has complementary variants A and B. The variant

A includes a Hp 5 capable of resting on a formed shoulder 6 of the variant shown as B. These two components can be brought together such that there is no need for the lip 5 to be carried down as an extension back to support directly from the pulin. This leads to a significant saving in metal and enhanced coverage which coacts together with the advantages that the ridge forms depicted as 1 can provide.

As shown in Figure 3 one or several indentations 7 can be provided on the underlying profile of any mated edge inter-engagement so as to avoid any capillary action. As can be seen, the doubled up form shown in Figure 3 is sufficiently reactive to forces that a penetrative fastener such as a headed screw can be driven down through into the support structure for the panels. Alternatively other penetrative fixers can be used.

Persons skilled in the art will appreciate that a form as depicted has the prospect of providing at least a 960mm total cover width from a 1220mm feed strip width using three pitches of ridges. All this with a 320mm pitch and a maximum trefoil arch height of, for example, 52mm. Typical radii for the forms can be, for example, 28mm for each of the curves 2 and 3 and for example 25mm for the curve 4. The intermediary ridges 8 can, if desired, be to a height of for example 4mm and of a radius by way of example of about 32mm.

Not only is there an efficiency in roofing coverage for a given amount of metal utilising the present invention there is also increased resistance to point loading deformation on the lapping ridges and increased resistance to buckling from point loads applied, for example, by foot traffic on all ridges.

The panels as stated can be used for exterior or other cladding. Walls and roofs are but examples.

The panels also adapt to formwork to support the formation of, and to reinforce, a concrete structure such as a floor, wall or the like.

The panels can be used to form a steel deck that is used as a component for constructing concrete floors. The deck acts as formwork for the concrete during construction, and remains adhered to the concrete to become reinforcement for the completed concrete floor. The shape and stiffness of the deck profile is enhanced giving an advantage of greater load-span capacity while the deck is acting as formwork.

A different embodiment to that already described is shown in Figures 4 to 10.

In this embodiment, the panel, in a preferred form of the present invention, covers a width of 945mm. This embodiment has a rib height of from 52mm to 48mm.

Any suitable material can be used for a panel as depicted but preferably it is either galvanised or other protected steel or metal (e.g. COLORSTEEL™) of the desired thickness required. A preferred material is sheet steel 0.4mm thick with an initial sheet width of 1220mm. Preferably the trefoil shape of each complete ridge is separated by a series of minor ribs for appearance and/or strengthening purposes, e.g. to a ridge height of, say, 3mm over, say, a 30mm spread for each minor ridge.

The trefoil ribs themselves preferably have a flat top lobe otherwise of, say, 26mm radius whilst the lower parts of the trefoil are similarly of, say, 26mm radius. Preferably however the lower part of the trefoil merge into a radius to the metal that extends to the next adjacent ridge feature.

As can be seen as the right ridge on Figure 4 that is the modified ridge form to be overlapped by the ridge form to the left of Figure 4 of a like and mating panel.