Note: Descriptions are shown in the official language in which they were submitted.
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A CLADDING ELEMENT
Field of the Invention
The present invention relates to cladding elements, more particularly to
cladding
elements adapted for side by side assembly with a like element.
The invention has been primarily developed in relation to cladding elements
which can be connected together along their longitudinal edges to provide
roofing/ceiling
sheets. However, it will be appreciated by persons skilled in the art that the
invention is
not limited to this particular use and also finds application in walling,
decking and other
types of cladding.
Background of the Invention
Australian patent no. 711048 discloses a cladding sheet marketed by BHP Steel
Pty Ltd under the Trade Mark FLATDEK. FLATDEK has a substantially flat web
with
generally triangular male and female formations along opposed longitudinal
edges. The
primarily usage of FLATDEK is of a roofing sheet with the web fastened to a
supporting
structure, such as battens or purlins by nails or screws which pierce the
sheets and engage
the support structure. The sheets are installed by pivoting the female
formation of the
sheet being installed over, and into engagement with, the male formation of
the last
installed sheet.
A disadvantage of FLATDEK is the sheets can only be connected by pivoting
the female formation over the male formation. This means that, when installing
from
within a room, FLATDEK can only be installed as ceiling sheets with the male
and
female formations projecting into the room space, which is visually
undesirable.
Accordingly, FLATDEK is normally only used a roof sheet.
Another disadvantage of FLATDEK is the fasteners used to attach it to the
support structure are visible. This is also visually undesirable.
The disadvantages described above in relation to FLATDEK are shared by the
majority of the cladding sheets presently available.
Object of the Invention
It is an object of the present invention to substantially overcome, or at
least
ameliorate, one or more of the disadvantages.
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Summary of the Invention
Accordingly, in a first aspect, the present invention provides a cladding
element
for use in a cladding element assembly, the cladding element including:
a substantially flat web having a pair of opposed longitudinal edges;
a male rib formation extending at least partially along one longitudinal edge
and
having a pair of spaced apart inner and outer upstanding ribs and an engaging
formation;
and
a female rib formation extending at least partially along the other
longitudinal
edge and having an inner upstanding rib, an outer depending rib and a joining
section,
between the inner and outer ribs and displaced from the plane of the web, and
a
corresponding engaging formation, at least one of the male or female rib
formations being
at least partially resiliently flexible,
wherein the element is adapted for assembly with a like element by positioning
of the male formation substantially within the female formation with their
respective
engaging formations in engagement, whereby the assembled male and female
formations
together form a substantially rectangular closed channel adapted for
concealment of
fixing means used to fix the cladding elements to a supporting structure.
When the major visible surface of the web is the side remote from the male and
female formations, the fixing means are positioned between the inner and outer
ribs of the
male formation. When the major visible surface of the web is the side adjacent
to the
male and female formations, the fixing means are positioned in the joining
section (ie.
between the inner and outer ribs of the female formation).
In one form, the engaging formation of the male rib formation is a flange
angled
inwardly and towards the web on the distal end of the inner male rib formation
and the
corresponding engaging formation of the female rib formation is a flange
angled inwardly
and away from the web on the distal end of the outer female rib formation. At
least one
of the inner male rib or the outer female rib are preferably flexible to allow
resilient
flexing displacement as the angled flanges ride over one another during
engagement.
The male and female rib formations are preferably both resiliently flexible.
In another form, the engaging formation of the male rib formation is an
outwardly directed flange on the distal end of the outer male rib formation
and the
corresponding engaging formation of the female rib formation is an outwardly
directed
recess on the distal end of the inner female rib formation.
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The cladding element preferably include both forms of the engaging formations
defined above.
Preferably, the proximal end of the outer male rib formation includes an
outwardly convex formation adapted to engage with an inwardly concave
formation on
the proximal end of the outer male rib formation.
The cladding element is preferably formed from a single piece of roll formed
steel.
The male rib formation is preferably formed by folding some of the web baclc
on
itself. A layer of adhesive is preferably included between at least some of
the web that is
folded back on itself.
In one embodiment, the layer of adhesive is an adhesive strip, most preferably
VHB (Trade Mark) tape marketed by the 3M company. In another embodiment, the
layer
of adhesive is a glue, most preferably Jetweld TS230 (Trade Maxk).
The web preferably includes a plurality, most preferably two, longitudinal
stiffening channels. The channels are preferably convex towards the rib
formations.
In a second aspect, the present invention provides a cladding element for use
in a
cladding element assembly, the cladding element including:
a substantially flat web;
a longitudinal interlocking formation formed by folding at least some of the
web
back onto itself; and
a layer of adhesive between at least some of the adjacent web folded back on
itself.
In one embodiment, the layer of adhesive is an adhesive strip, most preferably
VHB (Trade Mark) tape marketed by the 3M company. In another embodiment, the
layer
of adhesive is a glue, most preferably Jetweld TS230 (Trade Mark).
Brief Description of the Drawings
Preferred embodiments of the present invention will now be described, by way
of examples only, with reference to the accompanying drawings in which:
Fig. 1 is a perspective view of the cladding element according to a first
embodiment of the invention;
Fig. 2 is a front view of the element shown in Fig. 1 during installation as a
roofing sheet;
Fig. 3 is a front view after completion of the installation shown in Fig. 2;
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Fig. 4 is a front view of the element sheet shown in Fig. 1 during
installation as
ceiling sheet;
Fig. 5 is a front view of the element shown in Fig. 4 after installation;
Fig. 6 is a roll forming flower diagram of the sheet shown in Fig. 1; and
Fig. 7 is a partial front view of the cladding element according to a second
embodiment of the invention.
Detailed Description of the Preferred Embodiments
Referring firstly to Fig. 1, there is shown a first embodiment of a cladding
element 10 according to the invention. The element 10 is formed from a strip
of 0.42mm
base metal thickness (BMT) sheet steel. The element 10 is preferably produced
by role
forming, as will be described in more detail with reference to Fig. 6.
The element 10 has a substantially flat central web 12 with a male rib
formation
14 extending along one longitudinal edge and a female rib formation 16
extending along
the other longitudinal edge. When the element 10 is used as a roofing or
ceiling sheet, the
web side 12' is the lower most part (ie. the underside). When the element 10
is used as a
wall cladding sheet, the web side 12' is that which is visible from within the
clad room.
The web 12 also has a pair of longitudinally extending, substantially
parallel,
spaced apart minor stiffening ribs 18, which are convex in the same direction
as the male
and female rib formations 14,16.
The web is approximately 260mm wide with the stiffening ribs 18 being
approximately l2mm wide and extending away from the plane of the rib by about
Srnrn.
The male rib formation 14 is approximately 26mm wide and extends away from
plane of
the web 12 by about 44mm. The female rib formation is approximately 37mm wide
and
extends away from plane of the web 12 by about 45rnm. The elements 10 are
generally
produced in lengths of about 6 meters, with lengths of up to about 9.6 meters
possible
(generally subject to transporting limitations).
The male rib formation 14 comprises an inner upstanding rib 20 having an
angled flange 22 on its distal end. The flange 22 is angled inwardly and
towards the web
12. The male rib formation 14 also includes an outer upstanding rib 24 that
has an
outwardly directed flange 26 at its distal end and an outwardly convex channel
28 at its
proximal end. The male formation 14, with the exception of the inner rib 20,
is of double
thickness to that of the web 12 and is formed by folding the web over and back
on to
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itself, as will become more evident from Fig. 6. This folding advantageously
allows the
element 10 to be formed from a single piece of steel.
The female rib formation 16 has an inner upstanding rib 30 with an outwardly
concave recess 32 at its distal end and an outwardly concave channel 34 at its
proximal
5 end. A joining section 36 extends outwardly from the distal end of the inner
rib 30 and is
substantially parallel to and displaced from the web 12. An outer rib 38
depends from the
joining section 36 and has an angled flanged 40 at its distal end. The flange
40 is angled
inwardly and away from the web 12.
In the preferred embodiment shown, the thin sheet metal construction of the
element 10 results in various components of the male and female rib formations
14, 16
being resiliently flexible under load and able to be displaced from the
positions and
orientations shown in Fig. 1 and resiliently returned to those orientations
when no longer
subj ect to load.
Fig. 2 shows the cladding element 10, and a like cladding element 10', during
installation as a roofing sheet and being fastened to a supporting batten 42.
The
installation process begins with the cladding element 10 being fastened
adjacent the male
rib formation 14 by a fastener, such as a self tapping/drilling screw 44. The
screw 44 is
driven threw the element 10 between the inner and outer ribs 20 and 24 of the
male rib
formation 14. The female rib portion 16 of the cladding element 10' is pressed
over the
male rib formation 14 of the cladding element 10 and into locking engagement
with same.
During this engaging process, the rib 38 flexes outwardly as indicated by
arrow 46 and
the rib 20 flexes inwardly as indicated generally by the arrow 48 until the
angled flange
22 is received into engagement with the angled flange 40 as shown in Fig. 3.
When this
occurs the flange 26 is also located within the recess 32 and the channel 28
located within
the channel 34. There may also be some flexing of the rib formation 24 and 30
during the
engaging process, as indicating generally by arrows 50 and 52. The engaging
process can
also be assisted by initially tilting the element 10' away from the element 10
to initially
position the flange 22 in engagement with the flange 40 and then pivoting the
remainder
of the male and female rib formations 14 and 16 into engagement with one
another, as
indicated generally by the arrow 54.
Successive elements can thus be sequentially attached to another by following
a
similar method. The right hand end of the element 10 is preferably fixed to
the batten 42
by initially fastening a section of cladding element 10 that comprises only
the male rib
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formation 14 (not shown) and engaging the cladding element 10 with that
formation 14 in
the manner previously described.
With reference to Fig. 3, it can be seen that the male and female rib
formations
14, 16 form, after assembly, a substantially rectangular closed channel 56
which
advantageously conceals the screw 44. This advantageously obviates the need
for any
additional concealed fixing devices or clips, as are required for known
cladding sheets.
Further, the sheet material adjacent the recesses 28,32 forms a downwardly
concave
recess 58 in the bottom left hand corner of the channel 56, which
substantially replicates
the stiffening channels 18 and thus provides a uniform surface appearance to
the cladding
elements 10, 10' etc when viewed in the direction of arrow 60.
The installation of the cladding element 10 as a ceiling sheet will now be
described with references to Figs. 4 and 5 with like reference numerals used
to indicate
lilce features in Figs. 1 to 3.
Turning firstly to Fig. 4, the element 10 is initially fastened to the batten
42 by
passing the screw 44 through the connecting section 36 of the female rib
formation 16.
The cladding element 10' is then introduced into the position generally shown
in Fig. 4
and manoeuvred, in the direction of arrow 62, into engagement with the female
rib
formation 16 of the element 10 as indicated in Fig. 5. During the engaging
process the
ribs 20 and 40 flex, as generally indicated by arrows 46 and 48. There may
also be some
slight flexing of the rib 24 as generally indicated by arrow S0. The rib 30
will generally
not flex due to it being constrained by the attachment of the element 10 of
the batten 42.
As with the roofing sheet installation, the male and female rib formations 14,
16
form, after assembly, the substantially rectangular closed channel 56 which
conceals the
screw 44. Further, and again similar to the roofing sheet installation, the
male and female
rib formations 14, 16 also form a downwardly convex channel 58 which
replicates those
provided by the ribs 18 to provide a uniform and attractive ceiling appearance
when
viewed in the direction of arrow 60. The left hand end of the cladding element
10 is
initially fastened to the batten 42 by engagement with a female rib formation
16 (not
shown) previously fastened to the batten 42.
Figs. 4 and 5 also represent the top view of an installation of the element 10
as a
wall cladding with the surface 12' of the web 12 presenting a uniform,
visually appearing,
surface to the interior of the clad room.
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The forming of the closed channels 50 described above also provides improved
resistance to leaking compared to known cladding sheets, which rely on the
rubber
washers between the exposed fastener heads and the cladding sheets. Further,
when a
roofing installer is notching a tile flushing for a flush fit with the roofing
cladding, the
substantially rectangular channel 56 is a much easier shape for the notched
flushing to
conform to. This results in reduced installation times and less chance of gaps
and
associated leaks.
As mentioned above, the element 10 is preferably formed form a single piece of
metal by roll forming in accordance with the process shown in the roll forming
flower
diagram of Fig. 6.
Referring now to Fig. 7, there is shown a second embodiment of a cladding
element 70 according to the invention. Like reference numerals to those used
in
describing the first embodiment have been used to indicate like features in
the second
embodiment.
The element 70 is also formed from a strip of 0.42mm base metal thickness
(BMT) sheet steel and produced by the role forming process described with
reference to
Fig. 6. The roll forming process includes folding the web 12 back onto itself
to form the
male rib formation 14. This also results in there being two adjacent web
layers 72 and 74,
between the inner and outer upstanding ribs 20 and 24.
In the element 70, a 6mm wide strip of adhesive 76 (darkened region) is
inserted
between the layers 72 and 74 to prevent them from separating. The adhesive
strip is
preferably VHB (Trade Marlc) tape marketed by the 3M company. The tape is fed
into
the roll former during the roll forming process. Jetweld TS230 glue could also
be used
but the tape is easier to incorporate into the roll forming process.
As stated above, the adhesive strip 76 prevents the two web layers 72 and 74
from separating. This advantageously allows longer spans of the element 70 to
be
installed between fixings when compared to the element 10. Alternatively, the
element
70 can withstand higher wind loads than the element 10, when installed with
similar
fixing spacing.
Although the invention has been described with reference to a preferred
embodiment, it would be appreciated by those skilled in the art that the
invention may be
embodied in many other forms. For example, although it is preferred, it is not
necessary
for the male and female rib formation to extend over the entire length of the
cladding
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elements. An alternative is a series of discrete spaced apart lengths of male
and female
rib formations. Further, the element can alternatively be formed from sheets
of plastics or
other materials.
