Field of the Invention

(1 ) The present invention relates to fasteners and in particular to fasteners for wood products and the like.

(2) The invention has been developed primarily for the carpentry and building industries and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.

Background of the Invention.

(3) Fasteners such as screws, nails and anchor bolts have been manufactured with a variety of heads and drive designs, each requiring a different kind of tool to drive or extract them. All fasteners employ the same general fixing principle, with the shank, which may be threaded or serrated, providing gripping and the head providing a bearing surface and means to drive the fastener. One difficulty with such fasteners is the head by design is left exposed. In building applications, this leads to additional finishing work for the builder to finish the workpiece around the head.

(4) There is thus a need for a fastener which provides concealed fixing, in that the workpiece can be fixed in place as desired with the fastener concealed. This will allow builders to use pre-finished workpieces with further finishing work not being required.

(5) The inventor performed a comprehensive search of the market place and published patent publications and did not find a product which satisfies the inventor's requirements.

(6) The present invention seeks to overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative.

(7) It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country. The present invention seeks to overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative.

(8) It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.

Summary of the Invention

(9) According to a first aspect, the present invention provides a fastener extension for a fastener, the fastener having a fastener head and a fastener shank, the fastener extension comprising: a body having an aperture through which the fastener shank can extend through, the aperture being shaped for receiving the fastener head, and

an attachment means formed in the body and extending generally in an opposite direction to the fastener shank in use.

(10) Preferably, the body comprises means for holding the fastener head at least rotationally locked therewith.

(11 ) In one embodiment, the body is shaped as a washer.

(12) Preferably, the body is circular, rectangular or polygonal shaped.

(13) Preferably, the fastener extension further comprises means for locking the fastener head to the body.

(14) Preferably, the locking means comprises a correspondingly shaped recess in the head for engaging the fastener head.

(15) Preferably, the body comprises a head portion and a generally tubular shoulder portion extending from the head portion and opposite to the attachment means.

(16) Preferably, the shoulder portion defines a stop surface spaced from the head.

(17) Preferably, the shoulder portion has an external diameter larger than the diameter of the fastener shank.

(18) Preferably, the attachment means are prongs.

(19) Preferably, the body further comprises a depth measuring means for indicating the distance of the body from the workpiece in use.

(20) Preferably, the depth measuring means comprises a shoulder portion extending from the body.

(21 ) In another embodiment, the attachment means comprises prongs which are slightly splayed relative to each other.

(22) In another embodiment, each prong is adapted to substantially curl and/or skew into a second workpiece as the second workpiece is forced against the attachment means.

(23) Preferably, the aperture is formed at a central portion of the body.

(24) Preferably, the attachment means effectively extend from the fastener head in use.

(25) Preferably, the body comprises a recess correspondingly shaped to the fastener head.

(26) Preferably, the recess comprises converging side walls or polygonal side walls.

(27) In another embodiment, the recess comprises a formation for receiving a locking piece for engaging the fastener head in use. (28) Preferably, the fastener extension further comprises a drive tool for the fastener extension, the drive tool comprising a corresponding formation for receiving the attachment means of the fastener extension.

(29) Preferably, the attachment means are prongs and the drive tool comprises cavities for receiving the prongs.

(30) In another aspect the present invention provides a fastener extension for a fastener, the fastener having a fastener head and a fastener shank, the fastener extension comprising:

a body having an aperture through which the fastener shank can extend through, the body adapted to engage the fastener head, and

an attachment means formed in the body and extending generally in an opposite direction to the fastener shank in use.

(31 ) There is also provided herein a fastener in combination with the fastener extension of any one of the above.

(32) Other aspects of the invention are also disclosed. Brief Description of the Drawings

(33) Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings in which:

(34) Fig. 1 shows a fastener extension in accordance with a first embodiment of the present invention, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view;

(35) Fig. 2 shows a fastener extension in accordance with a second embodiment of the present invention, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view;

(36) Fig. 3 shows a fastener extension in accordance with a third embodiment of the present invention, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view;

(37) Fig. 4 shows the fastener extension of Figure 3 with the prongs thereof skewed in use, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view;

(38) Fig. 5 shows a fastener extension in accordance with a fourth embodiment of the present invention, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view; (39) Fig. 6 shows a fastener extension in accordance with a fifth embodiment of the present invention, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view;

(40) Fig. 7 shows a fastener extension in accordance with a sixth embodiment of the present invention, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view;

(41 ) Fig. 8 shows a fastener extension in accordance with a seventh embodiment of the present invention, where (a) is a top view, (b) is a side cross-section view, and (c) is a perspective view;

(42) Fig. 9 shows the fastener extension of Figure 1 ;

(43) Fig. 10 shows a drive tool for the fastener of Figures 1 , 2, 5, 6 and 8;

(44) Fig. 11 schematically shows the fastener of Figure 1 in use; and

(45) Fig. 12 schematically shows the fastener of Figure 5 in use.

Description of Embodiments

(46) It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

(47) Fig. 1 shows a fastener extension 10 in accordance with a preferred embodiment of the present invention. The fastener extension 10 comprises a body 12 having a central aperture 14 through which the shank of a normal fastener (e.g., screw, nail or bolt) can extend through, while the head of the fastener is held by the body 12.

(48) The body 12 comprises a washer shaped head portion 16 and a tubular shoulder portion 18. The head portion 16 comprises a first surface 24 and an opposite second surface 26. The shoulder portion 18 extends from the second surface 26.

(49) The aperture 14 in the head portion 16 comprises a recess 20 which is shaped to receive the head of the fastener extending through the aperture 14. In the fastener extension 10, the recess 20 is shaped to have converging sidewalls for receiving the correspondingly shaped head of a screw. The recess 20 also includes a locking means or an engagement formation such as ribs for engaging the screw head and providing a tight fit therewith. The screw head is received such that the screw is locked and rotatable with the fastener extension 10.

(50) The shoulder portion 18 has an external diameter larger than the shank of the fastener extending through its central aperture 14. The shoulder portion 18 defines a stop surface 21 at a distal end thereof spaced from the head portion 16.

(51 ) The head portion 16 further comprises attachment means 30 formed in the first surface 24, which in this embodiment are three prongs spaced around the aperture 14. The prongs 30 extend in an opposite direction to the shoulder portion 18. The prongs are of a length sufficient to attach a workpiece thereto as described below.

(52) In use, as for example shown in Figure 11 , the threaded shank 112 of a screw fastener 100 is inserted through the aperture 14 with the head 110 of the fastener held by the recess 20. The attachment means of the fastener, being its shank 112, will thus extend in a first direction, being a downward direction in Figures 1 (b) and (c). The attachment means 30 of fastener extension 10, being the prongs 30, will extend in the opposite direction, being upward in Figures 1 (b) and (c).

(53) Fig. 11 schematically shows the fastener extension 10 in use. The fastener extension 10 is added to a fastener 100 to provide the fastener 100 with an additional oppositely directed attachment means. In this example, the fastener 100 is used for fixing a plasterboard wall lining 42 to a frame stud 40, and the fastener extension 10 is used for fixing a pre-finished timber skirting 44 to the wall lining 42 to cover the gap 43 between the wall lining 42 and the flooring 46.

(54) The wall lining 42 has already been painted its final coat and is fixed to the frame stud 40 (timber, metal or masonry) via the threaded shank 112 of the fastener 100, up until the stop surface 21 of the fastener extension 10 engages the frame stud 40. The shoulder portion 18 thus also penetrates the wall lining 42. The head portion 16 engages the wall lining 42 providing a clamping force thereto towards the frame stud 40. This also locks the fastener extension 10 further in place with the prongs 30 extending outwardly. The fastener head 110 is substantially flush with the first surface 24, and the prongs 30 thus effectively extend from the fastener head 110. The timber skirting 44 is then forced into the additional attachment means 30, being the prongs 30. The face (front surface) 24 of the head portion 16 can also provide a stop to control/prevent flex of the skirting 44.

(55) Only the back surface of the skirting 44 is engaged by the prongs 30 and the front pre- finished surface 49 thereof is left unmarked. Thus, the fastener 100 and the fastener extension 10 provides concealed fixing of the skirting 44 and no further finishing is needed. The shoulder portion 18 via the stop surface 21 acts a depth measuring means in that the distance of the head portion 16 from the first workpiece (being the frame stud 40) for all of the fastener extensions 10 will be consistent.

(56) It is possible to drive the fastener 100 into the frame stud 40 via conventional means, such as a screwdriver. Preferably however, the screw head 110 is tightly fitted and locked to the head portion 16 such that the screw fastener 100 is rotatable with the faster extension 10. Fig. 10 shows a drive tool 120 for the fastener extension 10, also shown in Figure 9. The drive tool 120 is shaped as a socket having three cavities 122 for respectively receiving the prongs 30 of the fastener extension 10, such that the drive tool 120 can rotate and drive the fastener extension 10 with the fastener 100. Where the fastener extension has differently shaped prongs, such as that shown in Figure 3, the cavities 122 can be correspondingly shaped.

Figure 2 shows a fastener extension 10b which is substantially similar to the fastener extension 10 above. The fastener extension 10b however has a hexagon socket recess 20 shaped to receive the hexagonal head of a bolt. The fastener extension 10b is thus mostly suitable for use with a bolt fastener with a hexagonal head, which is locked for rotation with the fastener extension 10b via the hexagon socket shaped recess 20 (which acts as a rotation locking means).

Figure 3 shows a fastener extension 10c which is substantially similar to the fastener extension 10 above. The fastener extension 10c however has flat prongs 30 having pointed ends as their attachment means 30, instead of the rounded prongs in the fastener extension 10. The prongs 30 are slightly splayed from each other.

Figures 4a, 4b & 4c schematically show the skewing of the prongs 30 away from each other, when the prongs 30 for example engage the timber skirting 44 in use. The fixing prongs 24 skew away from each other and the end portions thereof curl outwardly as the skirting 44 is forced thereto. The skewed prongs curl to lock into the pre-finished timber.

Figure 5 shows a fastener extension 10d which is substantially similar to the fastener extension 10 above, except the fastener extension 10c does not include the shoulder portion 18. The fastener extension 10c only comprises the washer shaped head portion 16 and the prongs 30.

Use of the fastener extension 10d is shown in Figure 12, which is similar to that shown in Figure 11. The fastener extension 10d is used in applications where the shoulder portion 18 will not penetrate the wall lining 42, such as where the wall lining 42 is painted cement render or a tile made from ceramic or stone.

Figure 6 shows a fastener extension 10e which is substantially similar to the fastener extension 10d above. The recess 20 of the fastener extension 10e however is shaped to include radial teeth recesses 22 for receiving the teeth of a washer lock which further assists in engaging the head of the fastener 100 and stopping rotation of the fastener head relative to the fastener extension 10e. The teeth of the washer lock are locked in the recesses 22 as the washer lock further engages the fastener head.

Figure 7 shows a fastener extension 10f which is substantially similar to the fastener extension 10d above, except comprising a square or rectangular shaped head portion 16 rather than a circular head portion. The square head portion 16 can thus be engaged by a spanner for driving the fastener extension 10f with the fastener attached thereto in use. The fastener extension 10f also comprises four prongs 30 at the corners thereof.

Figure 8 shows a fastener extension 10g which is substantially similar to the fastener extension 10e above, except comprising a hexagonal shaped head portion 16 rather than a circular head portion. The hexagon head portion 16 can thus be engaged by a spanner for driving the fastener extension 10f with the fastener attached thereto in use.

The shaped bodies 16 of Figures 7 and 8 can also be applied to the fasteners of Figures 1 to 4.

Whilst preferred embodiments of the present invention have been described, it will be apparent to skilled persons that modifications can be made to the embodiments described.

For example, the fastener extensions can have any desired number of prongs and differently shaped prongs, such as serrated prongs. Another variation is the incorporation of 50% leading smooth pin that penetrates easier into the dense MDF and 50% serrations, and with fewer serrations, provides less resistance requiring less force for penetration into the dense MDF material.

In other embodiments, the serrated prongs can also be slightly splayed, and can be adapted to curl outwardly similar to the prongs above.

The fastener extensions of the preferred embodiment thus provides the ability to add an additional attachment means to conventional fasteners. The resulting assembly provides two-directional concealed fixing via a threaded shank or nail in one direction, and integrated fixing prongs in the opposite direction. The preferred fastener extension has integrated fixing prongs that are designed to bite, skew and curl into pre-finished timber. The preferred fastener extension has the integrated fixing prongs that provide a skewing and curling action locking the pre-finished timber towards the screw head. The integrated fixing prongs can generate a gripping a force greater than that of single trimming nails through the timber.

The preferred fastener extension can comprise a varying number of integrated fixing prongs in the screw head. The preferred fastener extension has a shoulder that provides a depth gauge to ensure all integrated fixing prongs protrude past the face of the plasterboard wall lining equidistantly. The preferred fastener extension can accommodate any variation of drive system within the head. The preferred fastener extension provides fixing from the back face of the material, and without penetrating the surface, allows for pre-finished timber to be used.

The preferred fastener extension provides concealed fixing as an alternative to the current nailing of internal timbers. This has been achieved with the threaded shank providing gripping to the wall frame, and the integral fixing prongs providing bite and penetration to pull the timber towards the crown, which provides for a very strong connection. The fixing prongs are an integral part of the screw head giving the screw head a crown like appearance.

The preferred extension is driven to the wall frame with the shoulder providing the predetermined bearing depth, ensuring correct engagement of the crown. The timber is positioned for fastening, with pressure being applied to the face of the timber, engaging the fixing prongs which bite into the timber. As more pressure is applied and the timber is forced home, the fixing prongs skew and curl into the timber which provides a powerful locking strength.

The fixing detail is such that the fasteners are secured to each stud frame via the threaded shank, with the shoulder of the fastener providing the bearing surface to ensure all screw heads are set at the same depth, thus providing consistent bite force to the timber skirting. The fixing prongs in the set position, protrude forward of the face of the Plasterboard Wall Lining, and have been designed to bite and skew into the timber Skirting, curling and pulling the pre-finished timber tight with the Plasterboard Wall Lining. The result is that the skirting remains a tight fit along the entire length of wall, thus minimising (or eliminating) the need for gap filler.

In another possible embodiment, the body can simply be a flat washer which does not have a recess fro receiving the fastener head. The fastener head will engage the head portion of the fastener extension when the fastener is driven into a workpiece.