AU686147B2 - Strap arrangement - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT STRAP ARRANGEMENT THE FOLLOWING STATEMENT IS A FULL DESCRIPTION OF THIS INVENTION, INCLUDING THE BEST METHOD OF PERFORMING IT KNOWN TO ME:- The present invention relates to a retaining clip construction for the concealed fixing of roofing or other cladding sheets.

Cladding sheets for concealed fixing have a plurality of longitudinal, re-entrant ribs, with pan sections between the ribs. The edges of the sheets are adapted for interengagement with the adjacent sheets, so that an end rib of one sheet fits over the end portion of the adjacent sheet.

The sheets are typically secured to the roof structure *by elongated clips which secure the trailing edge end portion of the previously laid sheet and the leading :.00 15 edge rib and intermediate ribs of the sheet to be laid. The clip has retaining formations spaced along the length thereof to coincide with the rib spacing.

An endmost retaining formation of the clip is engaged oooe with the trailing edge portion of the previously laid sheet, with the remainder of the clip extending in the direction of progress, and is fixed to the roof structure. The next sheet is then pressed onto the clip so that the leading edge rib and intermediate ribs are engaged with the retaining formations and the 25 leading edge rib also locks over the trailing edge portion of the previous sheet.

The prior art clip is formed as an elongate strap, extending between the leading edge rib and the -2intermediate rib, wl,:ch is folded at both ends to form hump-shaped retaining formations. The humps have detents for engagement with re-entrant portions of the ribs.

The present invention seeks to provide an alternative clip arrangement.

Accordingly, the present invention provides a clip for use in the concealed fixing of a series of successively laid cladding sheets, said series including three successively laid sheets (hereinafter referred to respectively as the first, second and third laid sheet), said first, second and third sheets being of the type having a trailing edge portion, one or more intermediate ribs and a leading edge portion adapted for engagement with the trailing edge portion of a previously laid sheet, the clip including a strap and a plurality of retaining formations, said strap being elongate and including spaced apart first and second ends, an endmost one of said retaining formations being adjacent said first end and at least one other of said retaining formations being located intermediate said first and second ends, wherein said endmost retaining formation being adapted for engagement with both the trailing edge portion of said first sheet and the leading edge portion of second sheet wherein said other retaining formations being adapted for o engagement with respective intermediate ribs of the second sheet, said clip further including a tail portion located at said second end which is configured to underlie the region of engagement between the trailing edge portion of said second sheet and a leading edge portion of the third sheet.

0 25 Further preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is a schematic perspective showing installation of a roofing sheet using a prior art clip; '54895 DOC

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-3- Fig. 2 is a plan view of a preferred clip in accordance with the present invention; Fig. 3 is a side view of the clip of Fig. 2; Fig. 4 is a perspective view of the clip of Fig. 2; Fig. 5A is a left hand end view of the clip of Fig. 2; Fig. 5B is a right hand end view of the clip of Fig. 2; Fig. 6 illustrates the cladding sheet profile for use with the clips of Fig. 2; Figs. 7A to 7D are schematic side views illustrating the installation procedure; and ii ~Fig. 8 is a detail side view of a retaining formation of the clip engaged with the leading edge rib of a sheet and the trailing edge portion of the previous sheet.

With reference to Fig. 1, the prior art fixing system 25 includes a clip 10 consisting of a flat strap which has been folded along lines 900 to its length to form hump-shaped retaining formations lla,llb at its ends.

.These formations have detents 12 therein to engage inside the female 13b and intermediate 14 ;'ibs of the roofing sheets 15a,15b. In use, the first hump lla of the clip is positioned over the male rib 16a on the trailing edge of the previously laid sheet 15a, and the clip is fixed to purlin 17 by screws at p<:ostions 18a and 18b. The second sheet 15b is then positioned with its female 13b and intermediate 14b ribs over the respective formations lla, llb and is pressed downwards to snap home over the detents 12 and to engage the female rib over the full length of of the male rib 16a. The procedure is repeated for subsequent sheets, with the male rib of the final sheet being held by a finishing clip.

Figs. 2 to 5 illustrate a preferred clip arrangement according to the present invention. The clip includes a strap 21 shaped for most of its length as a shallow, downwardly facing channel 22 (as best shown in Fig 5A). At point 23 the channel inverts to form an upwards facing channel 24 best shown in Figs. 4 and Three retaining formations 25 are attached to the strap, at positions corresponding to the leading edge rib 26 and the two intermediate ribs 27 of the roofing sheet 28 of Fig. 6. Each retaining formation is formed as a generally channel-shaped element in end 20 view, having a base 29 and a pair of opposed upright tabs 30 of a generally similar profile to the rib.

Each tab has a pair of downwardly facing shoulders 39 for location above the re-entrant portions 40 of the rib, an inwardly turned longitudinal top flange 31 and a pair of inwardly angled longitudinal flanges 32.

The faces of angled flanges 32 are adapted to abut the eeoe inside surface of the rib. There preferably is some clearance of the top longitudinal flange 31 and the top of the rib, to allow the rib to flex while being 30 snap-fitted onto the tab.

*As illustrated in Figs. 7A to 7D, the first clip is secured to the purlin by fasteners 35 passing through the fastener holes 36 in the strap between the tabs of each retaining formation. Securing the clip also compresses the insulation blanket 41.

As shown in Fig. 7B, the roofing sheet 28a is aligned above the clip 20a and pushed downwardly to snap fit the top portions of the ribs over corresponding barbed part of the tabs. Engagement between downwardly facing shoulders 39 of the tabs and opposed re-entrant parts 40 of each rib then prevent the sheet from being lifted out of engagement. The angled flanges 32 above the shoulders 39 fit tightly inside upwardly convergent top walls 42 of the rib to prevent twisting of the tab.

The next clip 20b is installed with the angled flanges 32 of the endmost retaining formation 25a hooking under the lip 43 of the trailing edge portion 33 of the previously laid roofing sheet 28a. The clip is pivoted downwards and secured to the purlin 34 by fasteners 35 passing through fastener holes 36 in the *clip (Fig. 7C).

The next roofing sheet 28b is then aligned above clip 20b and snapped home as described above for roofing sheet 28a, except that the leading edge rib 26 snaps over both the endmost retaining formation 25a and the e:oo trailing end portion 33 of the previous sheet. The 25 engagement between the two clips 20a,20b and the two S.sheets 28a,28b is described below with reference to o:oe Fig. 8.

Fig. 8 illustrates the overlap between two adjacent S: 30 sheets. The trailing edge portion 33 is shaped as one side of a rib, including an upwardly facing shoulder 44 shaped like the re-entrant parts 40 of the ribs.

The shoulder 44 of the end portion is held down by the near shoulder 39 of the tab in the same manner as the ribs. The downwardly turned lip 43 at the outer edge of the trailing edge portion is hooked behind the endmost angled flange 32 of the tab to prevent the

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shoulder 44 of the edge portion and the shoulder 39 of the tab from moving laterally out of alignment.

The illustrated retaining formations and the manner of c -inection with the projecting edge portion of the sheet allow fasteners to be positioned centrally below the longitudinal rib of the roofing sheet for greater wind uplift resistance and allows direct engagement between the retaining tabs and the leading edge rib. Furthermore, the short trailing edge portion allows greater material efficiency in the roofing sheet compared to the prior art.

The alignment of the tabs 30 across the rib profile results in the fold line 37 between the tabs and the base 29 of the retaining member being parallel to the clip length, rather than perpendicular as in the prior art. Furthermore, the angled flanges 32 of the retaining formation are closely received in the top 20 portion of the rib, restraining against bending of the clip in both the parallel or perpendicular directions.

Consequently, the wind uplift forces acting through the flanges 32 act substantially parallel to the plane o! the tab. Extreme uplift forces attempt to twist the tab. This mechanism results in considerably S.greater resistance to wind uplift forces than the prior art hump-shaped retaining formations, in which the uplift forces attempt to unfold the hump by bending along the existing perpendicular fold lines.

As the tabs substantially correspond to the rib profile, separate bird proofing accessories are not required.

ike prior art clips, the tail 38 of the clip extends past the final retaining formation 25c, thus supporting the full sheet profile and compressing the insulation blanket in the region of connection of the laid sheet with the next clip. This arrangement also allows the head of the next clip to nest within the channel section 24 at the tail of the previous clip, and the alignment of circular fastener holes 36 ensures exact positioning of the clips for correct roof pitching.

While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not *.restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

In the appended claims, the invention is defined with reference to the orientation for use in roof cladding, e e where the plane of the sheets is generally horizontal.

This however should not be construed as limiting the invention to that orientation. The present invention can, for example, be used for wall cladding.

.can, for example, be used for wall cladding.

Claims (6)

1. A clip for use in the concealed fixing of a series of successively laid cladding sheets, said series including three successively laid sheets (hereinafter referred to respectively as the first, second and third laid sheet), said first, second and third sheets being of the type having a trailing edge portion, one or more intermediate ribs and a leading edge portion adapted for engagement with the trailing edge portion of a previously laid sheet, the clip including a strap and a plurality of retaining formations, said strap being elongate and including spaced apart first and second ends, an endmost one of said retaining formations being adjacent said first end and at least one other of said retaining formations being located intermediate said first and second ends, wherein said endmost retaining formation being adapted for engagement with both the trailing edge portion of said first sheet and the leading edge portion of the second sheet wherein said other retaining formations being adapted for engagement with respective intermediate ribs of the second sheet, said clip further including a tail portion located at said second end which is configured to underlie the region of engagement between the trailing edge portion of said second sheet and a leading 20 edge portion of the third sheet.

2. A clip according to claim 1 wherein said tail portion is adapted to engage a .first end of a strap of a subsequent clip so as to facilitate alignment of said subsequent clip in relation to said clip.

3. A clip according to claim 2 wherein said tail portion is adapted for nested engagement with said first end of the strap of said subsequent clip.

4. A clip according to any preceding claim wherein said strap is formed as a downwardly facing channel and said tail portion includes an upwardly facing channel adapted to receive an end of the downwardly facing channel of the strap a, of said subsequent clip.

DJH 64898 DOC -9" A clip according to any preceding claim wherein apertures are located adjacent said first and second ends of said strap, and wherein the aperture adjacent the second end is adapted to align with the aperture adjacent the first end of a strap of a subsequent clip in installation of said clips.

6. A clip according to claim 5 wherein the aligned apertures are adapted to receive a fastener for securing the clips to an underlying structure. Dated this 28th day of August 1997 STRAMIT CORPORATION LIMITED Patent Attorneys for the Applicant PHILLIPS ORMONDE FITZPATRICK eS S t o: *t DJH '64898 DOC 1119YI-~- ABSTRACT An elongate clip (10) for concealed fixing of a second one of three successively laid, similar cladding sheets (28) of the type having intermediate ribs (27), a trailing edge (33) and a leading edge (26) which engages with the trailing edge of the previously laid sheet. The clip has an endmost retaining formation at a first end thereof for engaging the trailing edge of the first sheet and the leading edge of the second sheet, further retaining formations (25) for engaging respective intermediate ribs, and a tail (38) remote from the first end and extending to underlie the junction of the trailing edge of the second sheet and the leading edge of the third sheet. The tail may have means (24,36) for locating the first end of the 15 next clip. Recommended Figure: Fig. 4. I