The present invention relates to roofing tile clips, and in particular, to roofing tile clips for tile roofs supported by battens and constructed in cyclone prone areas.

Background Art

In a conventional tiled roof, the roof is supported by rafters which run down the slope of the roof from a ridge line to an eave. Running substantially horizontally across the rafters are a plurality of lightweight timber bearers called battens which are spaced apart at a distance which approximately corresponds to the length of each tile. The battens can be fabricated from either softwood or hardwood. The tiles are placed on the battens with a higher part of each tile overlying a lower part of an adjacent tile. Such tiles are typically terracotta or concrete and are relatively heavy. Thus in those areas where high winds are not to be anticipated, the tiles are either maintained in position by their own weight, or tied to the batten by small gauge soft wire. However, in those areas subject to cyclones (or hurricanes or typhoons as the storms are known in the northern hemisphere) clips are used to secure the tiles to the battens and so enable the tiles to resist updrafts created by cyclonic storms which would otherwise dislodge the tiles.

Australian Patent Specification No. 76700/74 (which substantially corresponds to US Patent 4,182,090) and Australian Design Registration No. 65856 disclose one form of prior art clip. Such clips have hitherto been fabricated from galvanised sheet steel and suffer from a number of inherent disadvantages to be described hereafter in more detail.

The genesis of the present invention is to provide an alternative clip, and a method of installing same, which at least ameliorates some of the above mentioned disadvantages.

Summary of the Invention

In accordance with a first aspect of the present invention there is disclosed a roofing tile clip for tile roofs supported by battens and constructed in cyclone prone areas, said clip having a hook means shaped to engage a tile, a fastener shank

receiving elongate base having a front face and rear end and shaped to permit the shank of a fastener having a head and a shank to be received by said base, and an intermediate portion interconnecting said hook means and said base, wherein said base is dimensioned to permit said clip when installed to have the head of said fastener bear against said front face, and thereby abut said rear end against the batten into which said fastener is fastened.

In accordance with a second aspect of the present invention there is disclosed a method of installing a roofing tile clip for tile roofs supported by battens and constructed in cyclone prone areas, said method comprising the steps of:

(i) placing said tiles on said battens with a higher part of each tile overlying a lower part of an adjacent tile,

(ii) placing the hook means of the tile clip defined in paragraph 1 over said higher part of a tile, (iii) if necessary, engaging a fastener having a head and a shank with said base, and

(iv) driving said fastener home into the batten supporting said adjacent tile to bring said fastener head into contact with said base front face and abut said base rear end with said batten.

Brief Description of the Drawings

Two embodiments of the present invention will now be described with reference to the drawings in which:

Fig. 1 is a perspective view of the prior art clip installed; Fig. 2 is an enlarged view of Fig. 1 without the tiles being illustrated and showing the detail of the construction of the clip;

Fig. 3 is a front perspective view of the clip of the first embodiment;

Fig. 4 is a rear perspective view of the clip of Fig. 3;

Fig. 5 is a view similar to Fig. 1 but showing the clip of Figs. 3 and 4 installed; Fig. 6 is a front perspective view of the lower portion of a two part clip of a second embodiment;

Fig. 7 is a rear perspective view of the upper portion of the two part clip of the second embodiment; and

Fig. 8 is a front perspective view of the assembled clip of the second embodiment.

Detailed Description As seen in Fig. 1, two tiles 1, 2 are arranged in adjacent courses with the tile 1 being in a course above the tile 2 so that water is shed from tile 1 onto tile 2. A higher part 11 of tile 1 overlies a lower part 22 of tile 2 to provide the desired overlap of the tiles. Only the batten 3 supporting tile 2 is illustrated in Fig. 1. A nail 4 which passes through the lower end 6 of a prior art clip 5 is partially driven into the batten 3. The upper end 7 of the clip 5 is formed into a hook which engages with the tile 1.

As seen in Fig. 2, the clip 5 is fabricated from galvanised sheet steel, such as that sold under the trade name GALVABOND with the clip 5 being formed by pressing or cutting from a large galvanised sheet. Accordingly, the edges 15 of the clip 5 are not galvanised but are unprotected steel. Preferably the hook 7 and upper portion of the clip 5 are provided with a pressed stiffening rib 17. At the lower end 6 a loop 16 is formed by shearing a medial strip so as to form an eye shaped opening 19 through which the shank 24 of the nail 4 can pass. It will be appreciated from Fig. 2 that the edges 26 of the loop 16 which are formed during the shearing of the clip 5 are also constituted by unprotected steel.

There will also be apparent from Figs. 1 and 2, that the clip 5 is essentially in contact with the tile 2 which overhangs the batten 3 and thus the edge of the clip 5 is spaced from the batten 3 a distance X indicated in Fig. 2.

The abovementioned arrangement suffers from several disadvantages. Firstly, it is prohibitively expensive to manufacture the clip 5 from a rust resistant material such as stainless steel, and thus galvanised sheet steel must be used. However, the edges 15 and 26 of the clip 5 are prone to rusting which is a particular problem in cyclone prone areas since these are located in the tropics and near tropical seas.

Secondly, ideally the nail 4 should be galvanised in order to protect the nail 4 from rust. However, the sharp edges 26 of the loop 16 in practice strip any galvanising material on the shank 24 of the nail 4. As a consequence, it is the practice

not to use the expensive galvanised nails but to instead use normal mild steel nails since a galvanised nail with the galvanising partly stripped away offers no practical protection.

Thirdly, the nail 4 is only partially driven into the batten 3 and this requires the exercise of some skill and judgement on behalf of the installer. In particular, if the nail 4 is not driven a sufficient distance into the batten 3, the nail 4 will not adequately secure the clip 5 to the batten 3. Conversely, if the nail 4 is driven too far into the batten 3, the head 4 can distort the lower end 6 of the clip 5, thereby damaging the clip and lessening its holding ability.

Turning now to Figs. 3-5, a first embodiment of the present invention will now be described. The tiles 1 and 2, the batten 3 and the nail 4 are as before. The clip 105 of the first embodiment is fabricated as a single piece by injection moulding utilising plastics material and it is formed from a hook 107 which is connected via an intermediate portion 108 with a base 106. As best seen in Figs. 3 and 4, the base 106 is preferably a hollow cylindrical tube having an interior aperture 119 which is shaped to receive the shank 24 of the nail 4. In addition, the base 106 is provided with a front face 111 and a rear end 112.

Preferably after manufacture of the clip 105, the nail 4 has its shank 24 passed part way through the interior aperture 119 so that the base 106 lies intermediate the head 34 of the nail 4 and the tip of the nail 4. As will be appreciated from Fig. 5, once the tiles 1 and 2 have been placed in position on the battens 3, it is then a relatively easy matter for the installer to place the hook 107 over the tile 1 and then drive the nail 4 as fully as possible into the batten 3. In this way, the installer does not have to use any judgement since the head 34 of the nail 4 comes to rest against the front face 111 thereby automatically abutting the rear end 112 of the base 106 against the batten 3 and also placing the base 106 in compression. The length of the base 106 is selected so that the clip 105 is then correctly spaced relative to the batten 3 and the tile 2. In this way, the hammer used to drive the nail 4 need not be wielded with the precision required for installation of Fig. 1.

The arrangements described in relation to Figs. 3-5 have a number of substantial advantages. Firstly, the clip 105 being fabricated from plastics cannot rust. Secondly, the nail 4 can be galvanised and can pass through the interior aperture 119 without stripping the galvanising from the nail thereby ensuring that the nail will be protected for a substantial period of time against rusting. Further, because the nail head 34 bears against the front face 111, and the rear end 112 abuts the batten 3, the position of the clip 105 relative to the tile 2 and batten 3 is automatically assured, something which is not the case in relation to the arrangement of Fig. 1. Finally, experimental results indicate that because the nail 4 is driven fully home into the batten 3, and the strength of the clip 105 is at least comparable with that of the prior art clip 5, the overall effect is that the upward force required to dislodge the tile 1 when the clip 105 is used, substantially exceeds the equivalent force required to dislodge the tile 1 when the clip 5 is used.

Turning now to Figs. 6-8, a two part clip 205 of a second embodiment is illustrated. The clip 205 is formed from an upper portion 201 illustrated in Fig. 7 and a lower portion 202 illustrated in Fig. 6. The upper portion 201 includes a hook 207 substantially as before and from which extends an upper strap 218 which is provided with a plurality of saw tooth serrations 219. The lower portion 202 includes a base 206 as before from which extends a lower strap 228 which terminates in a ratchet housing 229 having a through aperture 222.

As seen in Fig. 8, the upper strap 218 is able to be passed downwardly through the through aperture 222 in the ratchet housing 229 such that the serrations 219 engage with the ratchet mechanism and prevent upwards movement of the upper strap 218. That is, the upper strap 218 (and hence the hook 207) are only able to move downwardly in Fig. 8 and not upwardly, this direction of movement being indicated by an arrow in Fig. 8.

Preferably, the nail 4 is supplied already at least partially inserted into the base

206 so that the clip 205 and nail 4 form an assembly which can be handled by the tile installer.

The major advantage of the clip 205 of the second embodiment is that the distance between the hook 207 and the base 206 is adjustable, thereby enabling the clip 205 to be used with a wide range of tile sizes, shapes and configurations. Prior to installation, the hook 207 is spaced from the base 206 by a maximum extent, the nail 4 is driven home into the batten, and then the hook 207 is pushed downwardly in the direction of the arrow in Fig. 8 so as to engage the hook 207 with the tile 1.

A clip substantially in accordance with that illustrated in Figs. 6-8 was used to fabricate a test roof five ridge tiles in length and four rows of tiles in width with a pitch of 18°, rafters at 600mm intervals and terra cotta roof tiles. The test roof was tested in accordance with Australian and New Zealand standard AS/NZS 2050-2002 (Tests for Roof Tiles) by CSIRO MANUFACTURING & INFRASTRUCTURE TECHNOLOGY, North Ryde, Sydney, Australia. The clips were found to have an average tensile strength of approximately 180 Newtons. The test roof passed all cyclic pressure tests (8,000 cycles at 1.48kPa to 1 cycle at 3.7OkPa). After completion of the tests the load on the roof was increased to 4.05kPa at which point the perimeter seal (rather than the tiles or clips) failed. These test results substantially exceed loadings likely to be experienced during cyclonic (hurricane) storm events.

In the event of a cyclone, the weakest member in the assembly is the nail 4 which is liable to be bent upwardly, thereby releasing the tile 1 slightly and allowing the tile 1 to move upwardly to a small extent, often sufficient to relieve the momentary high stress at the peak of the storm. Thereafter the tiles can be re-seated and the hook 207 fully re-engaged with the tile 1 merely by pushing the hook 207 downwardly so as to further engage the strap 218 with the ratchet housing 229. Thus the now slightly bent nail 4 can be retained, without removal or straightening, for further service. Indeed the nail 4 may be strengthened by work hardening as a result of the deformation brought about by the slight bending.

Furthermore, in those instances where the battens are fabricated from hardwood, it is difficult to grasp the batten with sufficient force if using something other than a metal fastener. Thus clips which do not incorporate a metal fastener with a shank which penetrates the batten, are contra-indicated.

The foregoing describes only two embodiments of the present invention and modifications, obvious to those skilled in the roofing arts, can be made thereto without departing from the scope of the present invention. For example, a threaded fastener such as a self tapping screw is able to be used in place of the nail 4.

The term "comprising" (and its grammatical variations) as used herein, is used in the inclusive sense of "including" or "having" and not in the exclusive sense of "consisting only of.