The anchoring of a fitting such as, for example, the fastening required for a bolt used to clamp an item to a base member, is commonly carried out by drilling a hole in the base member and inserting a threaded boss of metal or plastics into the hole for retention there as a tight fit. This method, however, has not proved satisfactory where the base member is of certain mineral compositions in that cracking of the mineral material may result and the boss is prone to pull out. Although adhesives for such material may be available, they are not generally effective for bonding metal or plastics material to them.

It is an object of the present invention to provide a method, and the product of such method, by which this and similar anchoring problems can be to a large extent overcome.

According to one aspect of the present invention a method of anchoring a fitting to a base member comprises forming a cavity in the base member, the cavity opening from a surface of the base member, locating at least a part of the fitting within the cavity, and entering a plug- element having a bore therethrough into the cavity for retention within the cavity, the plug-element when entered into the cavity plugging the cavity-opening to trap said part of the fitting within the cavity with a portion of said part in register with said bore.

According to another aspect of the present invention there is provided a fitting anchored to a base member, wherein at least a part of the fitting is located within a cavity that opens from a surface of the base member, and a plug-element having a bore therethrough is retained within the cavity, the plug-element plugging the cavity- opening to trap said part of the fitting within the cavity with a portion of said part in register with said bore.

The fitting of both aspects of the invention may be a fastener for use in clamping or otherwise securing an item to the surface of the base member. The fitting may be, for example, a screw-threaded nut, having a screw thread aligned with the bore for engagement by a screw- threaded bolt, rod or other member inserted in the bore, for securing the item to the base member. It may, however, have an internally-threaded tubular portion that projects into the bore from under the plug-element; the tubular portion may extend the length of the bore to open at the surface of the base member, but may alternatively extend sufficiently to project beyond this. As an alternative, the fitting, whether for use as a fastener or otherwise, may involve a rod or other component that extends via the bore to project from the surface.

A base of the fitting may be located on the bottom of the cavity under the plug-element, and this and the underside of the plug-element may be engaged with one another to restrain the fitting from turning relative to the plug- element. In this regard, the underside of the plug- element may be recessed, and the base of the fitting may be a flange that is inset within the recess when the plug-element is entered into the cavity. The flange may be of an elongate configuration and the recess may then be of a substantially conformal configuration for

restraining the fitting from turning relative to the plug-element.

The plug-element may be retained within the cavity by adhesive, and may be of the same material as the base member.

The base member, which, for example, may be in a sheet or slab form, may be of natural mineral or of a man-made mineral material having a composition containing natural mineral particles in acrylic resin.

The fitting and the plug-element may be marketed in combination with one another for use in the provision of an anchored fitting in accordance with the invention.

A method of anchoring a fitting in a slab member, and the slab member with an anchored fitting as a product of the method, in accordance with the present invention, will now be described, by way of example, with reference to the accompanying drawing, in which: Figures 1 and 2 are, respectively, a sectional side- elevation and an exploded sectional view showing a fitting anchored to a slab base-member, according to the invention; Figures 3 and 4 are, respectively, a sectional side elevation and a plan view from above of the anchored fitting of the arrangement of Figures 1 and 2; and Figures 5 and 6 are, respectively, a sectional side elevation and a plan view from below of a plug-element used in combination with the fitting of Figures 3 and 4 for anchoring as illustrated in Figure 1.

The method and product of the method, to be described, involve the anchoring of a metal (or plastics) fastener in a slab member of a man-made mineral material that has a composition containing natural mineral particles in acrylic resin. In particular, the material of the slab member is a solid non-porous surfacing material which is homogeneously composed of one-third polymethyl methacrylate and two-thirds natural minerals with mineral aluminium trihydrate derived from bauxite as a main component, and which is sold under the Registered Trade Mark CORIAN by E. I DuPont de Nemours and Co..

The anchoring of a fastening to such material has previously been carried out by drilling a hole in the material and inserting a threaded boss of brass or nylon into the hole for retention there as a tight fit. This has not proved satisfactory, in that cracking of the man- made material may result and the boss is prone to pull out. Although adhesive for bonding the mineral material to itself is available, this is not effective for bonding metal or plastics material to it. The method and the product of the method, according to the invention, overcome these problems to provide strong anchoring.

Referring to Figures 1 and 2, a stainless-steel fastener 1 is in this case anchored in the slab member 2 of the man-made mineral material. The fastener 1 has (as indicated most clearly in Figure 2) an internally- threaded tubular portion 3 that is upstanding from a flanged-base 4, and is located within a respective cylindrical-cavity 5 in the member 2. The cavity 5 has an opening 6 in a face 7 of the slab member 2, and this opening 6 is plugged within the cavity 5 substantially flush with the face 7, by a cylindrical element 8 of the same material as the member 2. The tubular portion 3 of the fastener 1 is located within a central bore 9 of the

element 8 to extend the length of the bore 9 and open substantially flush with the face 7.

The element 8 is bonded in the cavity 5 using an appropriate adhesive for bonding the man-made mineral material to itself; an appropriate adhesive is that sold as"Joint Adhesive for DuPont CORIAN"under the Registered Trade Marks DUPONT and CORIAN, by E. I DuPont de Nemours and Co.. With the bonding of the element 8 in this way, the flanged-base 4 of the fastener 1 is securely trapped in its cavity 5 and, as illustrated in Figures 1 and 2, may be engaged by a screw-bolt 10 to clamp a fitment 11 to the face 7 of the member 2.

Further details of the fastener 1 and element 8, in particular the way in which the fastener 1 is restrained from turning within its cavity 5, and bonding of the element 8 is facilitated, will now be described with reference to Figures 3 to 6.

Referring to Figure 3 and 4, the fastener 1 is of one- piece construction, with its flanged-base 4 of elongate configuration having straight, parallel sides 12 and rounded ends 13. As shown in Figures 5 and 6, the underside 14 of the element 8 has a recess 15 that is to the same elongate configuration so that it receives the flanged-base 4 inset therein. More especially, the recess 15 has straight, parallel sides 16 and rounded ends 17 conforming to the sides 12 and ends 13 respectively.

Accordingly, the method of assembly with anchoring of the fastener 1 within the slab member 2 can be readily carried out, once the appropriate cavity 5 has been drilled, simply by first bringing the fastener 1 towards the underside 14 of the element 8 with the tubular portion 3 in register with the bore 9 within the recess

15. The fastener 1 is now closed onto the underside 14 to extend the portion 3 the full length of the bore 9 and inset the flanged-base 4 within the recess 15. Abutment of the sides 12 with the sides 16 in this assembly precludes turning of the fastener 1 relative to the element 8.

The assembled fastener 1 and element 8 are now inserted into the cavity 5 to bring the flanged-base 4 down into abutment with the bottom 18 of the cavity 5, after a film of the appropriate adhesive has been deposited on the bottom 18 and side wall 19 of the cavity 5 (Figure 2).

The underside 14 of the element 8 is cut away to leave a peripheral channel 20 with interconnected axially- extending surface channels 21 for dispersal of surplus adhesive (Figures 5 and 6).

In one application of the invention a slab corresponding to the slab 2 forms a door to a kitchen cabinet, and a bracket of a hinge is clamped to the back face of the slab using four screw-bolts. Each screw-bolt is engaged tightly with a fastener corresponding to the fastener 1, as used in combination with a plug-element corresponding to the element 8, for anchoring the fastener firmly to the slab.