It is a common requirement within the building and associated industries to be able to securely fasten one or more predominantly flat panels to an existing substrate or decking.

One example of such a requirement is in securing preformed fibreglass or plastic roofing panels to an existing or new roof decking. Although conventional fixings such as nuts and bolts or screws may be used this invariably requires a hole to be made through the roofing panel. To ensure that the roofing panel is subsequently weatherproof some means of "repairing"the roofing panel is required, for example either by applying a patch of similar material to the roof panel over the fixing point in a weatherproof manner or by using some other kind of sealant around the fixing point. Whilst it is possible to make such patches or repairs in a weatherproof manner, it is a particularly skilled job that as well as requiring skilled operators, increases the length of time required to fix the roof panels to the roof decking. If not done correctly, the repair or seal may still in time deteriorate allowing the ingress of moisture. Even in applications other than roofing panels, for example flooring systems, it is highly undesirable to have to form fixing holes in the individual panels and generally undesirable to have the fixings remain visible and not flush to the surface of the panels.

A further disadvantage of conventional fixings is that although they may securely fasten the appropriate panels to a substrate, they do not allow any lateral movement of the individual panels, for example to accommodate thermal expansion and contraction of the panels.

Depending on the material used, such thermal expansion and contraction can be substantial and if no provision is made for this lateral movement of the panels then the stresses and strains induced due to the expansion or contraction can easily fracture the panels.

According to a first aspect of the present invention there is provided an anchoring device that comprises first and second elements, the first element having a substantially planar body section having an anchor portion extending substantially normally therefrom, arranged, in use, to provide an anchor point at which the first element may be secured to a substrate, the second element having a substantially planar body section having an aperture therein through which, in use, the anchor portion of the first element is arranged to pass, the anchor portion and aperture having relative dimensions to one another such that in use lateral motion may occur between the first and second elements of the anchor device, the second element having an adhesive member secured to a peripheral portion thereof arranged to adhere a further planar element to the anchoring device.

It is therefore possible to provide a fixing member for fixing a substantially planar element to a substantially planar substrate, the fixing member comprising a first fixing element having a first portion arranged to receive securing means to secure the first fixing element to the substrate and having a second portion extending from the first portion substantially parallel to, and spaced away from, the substrate, the fixing member further comprising a second fixing element having an aperture therein arranged, in use, to allow the first fixing element to extend there through, whereby a portion of the second fixing element is located between the second portion of the first fixing element and the substrate, the second fixing element being free to move in the plane of the substrate, the second fixing element having a peripheral portion having an adhesive member secured thereto which, in use, is arranged to adhere the substantially planar elements to the second fixing element.

Preferably, the anchor portion of the first element is centrally located on the first element and preferably forms a dished region. The anchor portion may have a hole therein to allow a fastener such as a bolt, screw or other mechanical fixing to pass there through.

Preferably, the aperture in the second element is centrally located.

Preferably, the first and second element of the anchor device are the same shape and more preferably are both circular. The first and second elements may be constructed from metal, preferably stainless steel or aluminium.

An embodiment of the present invention will now be described, by way of illustrative example only, with reference to the accompanying figures, of which: Figure 1 schematically illustrates the constituent elements of an anchor device according to an embodiment of the present invention and their arrangement with respect to a roofing deck and roof panel; Figure 2 shows a cross-section of the anchor device illustrated in Figure 1 in use; Figure 3 schematically illustrates in perspective the constituent elements of an anchor device according to an embodiment of the present invention; and Figure 4 shows a cross-section of an element of an anchor device according to a further embodiment of the present invention.

An anchor device according to an embodiment of the present invention is schematically illustrated in Figure 1. In the embodiment described the anchor device is intended to be used to secure a roof panel, such as a preformed fibreglass or plastic roof panel, to existing roof decking. However, it will be appreciated that this is merely one example of many applications for the anchoring device according to the present invention. The anchoring device comprises a first element 1 that has a substantially planar body portion 2. Located substantially centrally to the planar body portion 2 is an anchor section 3 that extends from the body portion 2 in a direction substantially normal from the plane of the body portion 2.

In the embodiment shown in Figure 1, and as will be more clearly seen with reference to Figure 3, the first element 1 is substantially circular in shape and the anchor portion 3 is formed by a dished section located substantially in the middle of the first element 1 and defining an aperture 4 through which a fastener, such as a conventional bolt, screw or other mechanical fixing may be passed in the direction indicated by the arrow 5 to secure the first element 1 to a section of the roof decking 6. The angle of the sidewalls of the anchor section 3 relative to the substantially planar body portion 2 can vary across different embodiments, although a preferred angle is 45°. As the anchor section 3 extends normally from the planar body section 2 of the first element 1, the body section 2 is spaced away from the roof decking 6.

Interposed between the first element 1 and the roof decking 6 is the second element 7 of the anchor device. The second element 7 comprises a circular, planar body section having a substantially central aperture 8. As can be seen from Figure 1, the dimension of the aperture 8 is greater than the diameter of the anchor portion 3 of the first element 1 of the anchoring device, which, in conjunction with the spacing of the body portion 2 of the first element 1 from the roof decking 6, allows the second element 7 of the anchor device to move laterally with respect to the first element 1. That is to say, that the second element 7 is free to move over the roof decking 6.

However, the dimension of the aperture 8 and the second element 7 is restricted such that there remains overlapping portions of the body portion 2 of the first element 1 and the second element 7. Therefore, the first element 1 of the anchor device, when fastened to the roof decking 6, still prevents the second element 7 of the anchor device from being lifted away from the roof decking 6. It will be appreciated that the extent of protrusion of the anchor portion 3 of the first element 7 of the anchor device should closely match the thickness of the second element 7 so as to restrict the movement of the second element 7 away from the roof decking 6 to a minimum, whilst still allowing the lateral movement of the second element 7 of the anchor device with respect to the roof decking 6 and the first element 1 of the anchor device.

Secured to the outer portion of the second element 7 of the anchor device is an adhesive member 9, which in the embodiment illustrated in Figure 1 is the form of a ring. Whilst it is not necessary for the adhesive ring 9 to be located at the absolute edge of the circular second element 7 or the anchor device, it must be sufficiently spaced away from the central aperture 8 so as to avoid coming into contact with the outside edge of the first element 1 of the anchor device over the full range of permitted lateral movement of the second element 7. The adhesive member 9 is arranged in use to adhere a preformed roof panel 10 to the second element 7 of the anchor device 1. It will therefore be appreciated that the adhesive member 9 must be of sufficient thickness so as to space the roof panel 10 away from the first element 1 of the anchor device, whereby the roof panel is then free to move laterally with respect to the first element 1 of the anchor device by virtue of being securely adhered to the second element 7 of the anchor device.

In alternative embodiments a mechanical fixing is provided on the second element 7 to allow a root panel 10 to be secured to the second element. The mechanical fixing may take the form of one or more self-tapping screws passed through respective apertures in the second element 7 and screwed into the root panel 10. In this case, the root panel would have to be thick enough to allow the screw to exert sufficient restraining force without piercing the outer skin of the root panel. Alternatively, the mechanical fixing may be in the form of an protruding lug formed on, or secured to, the second element 7 that engages with an appropriate bracket on the underside of the root panel 10. It will of course be appreciated that other mechanical fixing means may be used.

The anchor device according to embodiments of the present invention therefore permits relative movement in a lateral direction between a roof panel and roof decking whilst still securely anchoring the roof panel to the decking to prevent the roof panel lifting away from the decking, for example under the force of a gust of wind. Further advantage is that the lateral movement is provided without the requirement of making any holes in the preformed roof panel which would need subsequent repair.

Figure 2 further illustrates the anchor device shown in Figure 1 in use. Where appropriate, the same reference numerals have been used to reference the same parts. The first element of the anchor device 1 is secured to the roof decking 6 by means of a threaded bolt, screw or other mechanical fixing 20. The adhesive member 9 has a sufficient depth such that the roof panel 10 adhered thereto is still spaced away from the bolt or screw 20.

Figure 3 schematically illustrates in perspective the shape and relative dimensions of the first and second elements 1,7 and adhesive number 9 of an anchor device according to an embodiment of the present invention. The first element 1 may, for example, be of the order of 50mm in diameter and may, for example, be approximately 0. 7-l. lmm in thickness.

The second element 7 of the anchor device is also shown as being circular. Although it is not essential to the operation of the anchor device that the first and second elements 1,7 are of the same shape, it is preferred. The second element 7 may have a diameter of, say, 120mm, with the diameter of the central aperture 8 being approximately 30mm. Again, the thickness of the second element 7 is likely to be approximately 0.75mm. In preferred embodiments, both the first and second elements 1,7 are made from metal, preferably stainless steel or aluminium, although any other sufficiently strong and rust resistant material may be used.

Any suitable adhesive may be used for the adhesive member 9, depending on the material that the roof panel, or other panel according to the intended application, is made from.

Preferably, the adhesive is such that a chemical bond is formed between the roof panel 10 and the adhesive member 9. Preferably, a removable backing sheet is provided on the exposed surface of adhesive member 9 that is intended to be removed prior to the roof panel being adhered to the adhesive member 9. This makes the anchor device easier to handle before use. However, it is intended that the adhesive member 9 is secured to the second element 7 in a permanent manner at the time of manufacture of the anchor device.

An alternative form of the second element 7 according to a further embodiment of the invention is shown in cross-section in Figure 4. A circular indent 12 is formed in the second element 7 approximately mid-way between the outer edge of the second element and the periphery of the central aperture 8, although the spacing may vary. In a further variant a number, for example 3, dimples are formed rather than the circular indent 12.

When in use, only the circular indent 12 or dimples are in contact with the roof decking 6, or the like, as opposed to the entirety of the lower surface of the second element 7 in accordance with the embodiment shown in Figures 1-3. Consequently, there is reduced friction between the second element 7 and the roof deck 6, such that an affixed roof panel 10 can move laterally with respect to the roof decking 10 with reduced stresses involved, thus further reducing the likelihood of damage to the roof panel 10. The circular indent 12 or dimples also serve to further space the second element from other elements of the anchor device.