The present invention relates to roofing tile clips, and in particular, to roofing tile clips for tile roofs constructed in cyclone prone areas.
In one form 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 underlying 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) batten 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.
In another type of conventional typed roof the rafters are covered by a sheet layer such as plywood which forms a deck. This is then covered with a waterproof membrane or layer of some kind Tiles are then laid on the deck either with or without battens being laid. Battens are laid as above mainly on steeper rooves having a deck. Such tiles are held in place against high winds by means of a metal deck clip.
Australian Patent Specification No. 76700/74 (which substantially corresponds to U.S. Pat. No. 4,182,090) and Australian Design Registration No. 65856 disclose one form of prior art batten 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 a desire to provide an alternative clip, and a method of installing same, which at least ameliorates some of the above mentioned disadvantages.
In accordance with a first aspect of the present invention there is disclosed a roofing tile clip fabricated in two parts, one of said parts comprising an elongated strip having a plurality of teeth extending from one side thereof and terminating in a hook shaped to engage with the side edge of a substantially planar roofing tile, the other of said parts comprising a generally tubular body having a longitudinal axis and an opening therethrough substantially aligned with said axis and shaped to receive said strip, said tubular body having a ratchet mechanism arranged to co-operate with said teeth and permit movement of said hook towards, but not away from, said tubular body, and said other part including an elongate base which extends generally at right angles to said longitudinal axis, said base including at least one bore therethrough shaped to received a fastener for said clip, and said base having an abutment surface substantially perpendicular to said bore which, after installation, bears against a support surface, and through which said fastener can extend.
In accordance with a second aspect of the present invention there is disclosed a method of installing on a sloping first tile of a roof, a roofing clip as described above, said method comprising the steps of:
(i) bringing said abutment surface of said base into contact with said support surface,
(ii) driving a fastener through said base and into said support surface to secure said other part thereto, and
(iii) after carrying out steps (i) and (ii) bringing said hook into contact with said tile whilst simultaneously passing at least some of said teeth through said ratchet mechanism.
Two embodiments of the present invention will now be described with reference to the drawings in which:
As seen in
As seen in
It will also be apparent from
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.
The tiler or roofer does not know exactly how hard to drive in the nail because the nail is never driven fully home. If the nail is driven in too far, of the clip will be bent, thereby distorting the entire device and resulting in the hook 7 being dislodged from the tile. Alternatively, if the nail is not driven in far enough, the head of the nail does not abut the clip 5. In this position, if the wind should lift the tile 1, the hook 7 will tend to move towards the tile 2 and the loop 16 will tend to slide towards the head 34 of the nail 4. As a consequence, an increased bending moment is applied to the nail, which then results in the shank 24 of the nail 4 bending upwardly. As a consequence of this bending, the original tension in the clip 5 caused by the placement of the nail 4 is lost and the hook 7 will work loose from the tile 1.
As seen in
Furthermore, the clip 50 has a fixed hook height. As a consequence each different type of tile requires a corresponding special clip so that a large inventory of different clips 50 must be maintained to suit each corresponding different tile type. Also somewhat paradoxically, new tile designs are designed to use one of the existing ranges of clips 50, so the fixed hook height is a restraining parameter which inhibits the design of the new tiles and tiles of different styles.
Both the prior art clips 5 and 50 attempt to hold the tiles 1, 2 rigidly in place. However, the rafters of the roof do not form an entirely uniform surface. Battens where present are only rough sawn and are not formed from dressed timber, the plywood of roof decks is not of exactly uniform thickness, and so on. All of these dimensional tolerances result in a roof surface which is slightly undulating. Once the tiles are laid and the clips 5, 50 installed, the clips 5, 50 are covered from view by overlapping portions of adjacent tiles. As a consequence a person, such as a tiler, waking on the tiles after the clips 5, 50 are installed, by treading on the tile upper surface can bring the lower surface of that tile into contact with the top of the rigid hook 7, 57. Thus the trod on tile is sandwiched between the tiler's foot and the hook 7, 57. Often times this compressive force is enough to break a tile.
In this connection it should be noted that the sloping tiles 1, 2 are the only tiles upon which a tiler, or other person on a roof, walks. Such a person never walks on the ridge tiles at the intersection of two opposed roof surfaces. This is because the ridge tile is very narrow and to walk along ridge tiles is akin to walking along a tightrope (and thus extremely dangerous). Instead a person walking along a ridge puts one foot on the sloping tiles adjacent one side of the ridge and the other foot on the sloping tiles adjacent the other side of the ridge. Thus the ridge tiles are straddled rather than walked on. As a consequence of this universal practice, ridge tiles have different requirements from those of sloping tiles.
Turning now to
The clip 205 is formed from an upper portion 201 illustrated in
As seen in
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.
A major advantage of the clip 205 of the first 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. As seen in
A clip substantially in accordance with that illustrated in
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 engage the batten with sufficient force if using something (such as a wire) other than a metal fastener. Thus clips which do not incorporate a metal fastener with a shank which penetrates the batten, are contra-indicated.
An important consequence of the base 206 extending at right angles to the strap 218 and having a free end which abuts the batten, is that the length of the base 206 determines the set out of the strap 218 from the batten 3. Consequently, the tiler does not need to estimate the amount of force required to position the clip 205 as is the case with the prior art clip 5 of
Turning now to
As best seen in
The strap 318 is preferably a slightly loose fit within the aperture 322 and so can be worked slightly to the left or right as seen in
As best seen in
It will be appreciated from the above that in the first embodiment of
The above described and illustrated embodiments provide a number of substantial advantages over the prior art.
Firstly, the clips 205 and 305 are easily installed since the hook 207, 307 is pushed downwardly to engage the tile 1 after the clip 205, 305 has been secured to the batten 3 or deck 51 respectively. Conversely in the prior art the hook is engaged with the tile and then the nail(s) is/are driven home.
Secondly, the clip 205 allows the nail 4 to be driven fully home since the spacing between the hook 207 and the batten 3 is determined by the specific length of the base 206, and not by the force (or cumulative force) applied to the nail. Thus the overall installation is much easier.
Thirdly, since the distance between the hook 207, 307 and the base 206, 306 is adjustable, the one roofing clip can be used for a wide variety of tiles and in a wide variety of installations. Thus the prior art problems of the large inventory of different types of clip and a stultifying effect on tile design and innovation are overcome.
Furthermore, the prior art problem of sloping tiles breaking if persons walk on them is also overcome. This is because the hook 207, 307 instead of being rigidly secured to the batten or roof deck (and thereby forming a potential tile fracture site) has a certain amount of “give”. This is inherent in the ratchet mechanism 229, 329 which allows the hook 207, 307 to depress when a vertically downward force (or force component) is applied to it. Tilers are audibly reminded of this advantage when walking on sloping tiles secured with the roof clips of the present invention since the sound of the ratchet mechanism tightening by a notch or two can be heard (rather than the sharp snap of terra cotta tiles breaking). It is therefore advantageous after the initial installation for the tile which overlies each clip to be trodden on by the tiler as a means of further tightening the installation.
This is to be contracted with the disclosure of U.S. Pat. No. 4,047,353 (Aarons) which relates to ridge caps which are normally secured by mortar. The use of mortar teaches away from the present invention since sloping tiles are not secured by mortar, thus the problem solved by the U.S. Pat. No. 4,047,353 specification doe not arise with sloping tiles. Still further, the mortar is of little use against high winds since it is incapable of providing any tensile strength (only compressive strength). Furthermore, the clips of this US patent are not concealed by adjacent tiles but are instead visible after installation (see
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”.
Number | Date | Country | Kind |
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2004906609 | Nov 2004 | AU | national |
2004906732 | Nov 2004 | AU | national |
Number | Date | Country | |
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Parent | 11283019 | Nov 2005 | US |
Child | 12175043 | US |