NZ245591A - Stiffened pan building panel with edge profiles formed to enable interlocking with adjacent panels - Google Patents

Description

Priority Date(s): Compete Specification Filed: Class: £ <?ifc-.Q3j3Q, .3fcS,. }&$. $<?J; ,.

Publication Date: .... & 8. WAR .1995 P.O. Journal, No: PATENTS FORM NO. 5 Fee No. 1 & 4: $340.00 PATENTS ACT 1953 COMPLETE SPECIFICATION P4TPi, -'IT 23 Op- OEc Cp w / AN IMPROVED PANEL PROFILE WE STRATCO (AUSTRALIA) PTY LIMITED of Cavan Road, Gepps Cross, South Australia, Australia, an Australian company incorporated under the laws of the State of South Australia hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: (Followed by Page 1 A) 1 This invention relates to an improved panel profile, and in particular relates to a panel having interlocking edges that is designed to resist unclipping of the edges under normal loads.

Panel sheeting or decking is produced with a great variety of profiles. The profiles vary from simple corrugations to channel sections having interlocking edges. Such decking profiles are normally produced using roll 10 forming techniques, and are produced in set widths and can be produced in varying lengths.

Such decking or sheet panels have a variety of applications, but normally are used in relation to roofing 15 members. In order to produce a weatherproof joint, such decking panels are normally provided with either overlapping edges, or the edges are formed so that adjacent panels clip together.

In order to form a joint, each edge of a panel is provided with, on one edge a male or inner edge portion, and on the other side a female or outer edge portion. Therefore, adjacent panels can be interlocked by engagement of the inner and outer portions.

Normally, the inner and outer edge portions comprise in cross-section an upstanding channel, and the outer edge portion is designed to overlap the inner edge portion. Normally, the outer edge portion is designed to resiliently 30 deform thereby resulting in a joint, which, once forced together.

Although under normal light loads, such clipping arrangements are satisfactory, it has been found that higher 35 loads which are applied perpendicularly to the surface of the sheeting causes buckling and unclipping of the joints. This unclipping tends to occur at relatively light loads, and obviously if the join lines could remain clipped, then much higher loads could be withstood by the assembled panels. -1A- B J J" Such known edge joints for panels have previously always been asymmetric about a vertical centre line. It is due to this asymmetry which results in the buckling of the joint when normal forces are applied.

This buckling and resultant unclipping is due to torsional forces along the joint which result from forces applied perpendicularly to the assembled panels.

Generally, when shear stress is distributed across a cross-section, the resultant force will act through a vertical line in the cross-section. This line or point on the cross-section is known as the shear centre, and the shear centre does not coincide with the centroid of the cross-section other than when the cross-section is symmetrical about a vertical line. Therefore, the resultant shear force which acts through the shear centre produces a bending moment about the centroid, which results in a torsional force being applied to the section.

In known examples of edge joints for panels, it is this asymmetry and resulting torsional force which causes buckling and unclipping of the joint.

Therefore, by making the respective portions of the edge joints so as to form an assembled joint which is symmetric about a vertical line, the torsional forces can be eliminated or reduced so as to prevent buckling and unclipping of the joint when forces are applied perpendicularly to the panel.

This then results in assembled panels being able to withstand significantly increased forces.

Therefore, it is an object of this invention to provide an interlocking edge portion with a cross-sectional shape that is less likely to unclip as a result of perpendicular forces applied to assembled panels. -2 In its broadest: form, the invention comprises a panel having locking edge portions arranged on two of the opposed edges of the panel which are adapted to connect in interlocking fashion, comprising an outer locking edge 5 portion on one side of the panel having a channel-shaped cross-section, and an inner locking edge portion on a side of the panel adjacent to the outer locking edge portion having a channel-shaped cross-section that locates within the outer locking edge portion of an adjacent panel such that the inner 10 locking edge is held with respect to the outer locking edge portion, the interlocking inner and outer edge portions of adjacent panels having a cross-sectional shape which is symmetric about a vertical axis that extends between the edges of adjacent panels.

In another aspect of this invention, it is a requirement that any assembled panels be aesthetically pleasing in their appearance. In respect of sheet metal panels which are used for carports or garages, it is not normal to provide any 2o lining on the underneath surface of the panel. Therefore, it is desirable that the panel have a uniform and aesthetically pleasing appearance when viewed from underneath.

This has not normally been possible with some sheet 25 metal sections. This is particularly so in relation to panels which are formed into channel-like sections where a pair of channels are formed to produce a single sheet. The channels are normally defined by the edge locking portions, and a single rib that runs through the centre of the panel. 30 The central rib comprises a substantially U-shape cross- section, and obviously when viewed from underneath there is a somewhat irregular pattern formed as a result of difference in spacing between adjacent sheets when clipped together. In particular, there is a difference of appearance between the 35 gap at a clip compared to the gap at a central rib.

Further, any minor reinforcing corrugation or ribs which may be formed in the panel between the rib and adjacent edge may not match the appearance of gaps between adjacent edges and the gap formed by the central rib. Therefore, when viewing several assembled sheets from underneath, a somewhat haphazard pattern is observed.

Therefore, it is a further object of this invention to provide a panel profile which has a more aesthetic appearance when viewed from underneath the assembled panels.

Therefore in a further aspect of this invention, at the 10 abutment line between adjacent panels, the edge of each panel is shaped such that a channel is formed between the panels below said inner and outer edge portions which has substantially the same cross-sectional shape as any stiffening channels or ribs located between the inner and 15 outer edge portions.

This results in a more uniform and aesthetically pleasing appearance when assembled sheets are viewed from underneath. Although a more pleasing visual appearance is 20 produced, the strength properties of the assembled profile is not reduced significantly.

In order that these and other aspects of this invention may be readily understood, a preferred embodiment will now be 25 described, however it should be realised that the invention is not to be confined or restricted to the precise details of this embodiment.

This embodiment is illustrated in the accompanying 30 diagrams in which: Fig. 1 shows an end view of a panel, Fig. 2 shows a perspective view of a panel, and Fig. 3 shows a cross-sectional view of interlocked adjacent edge portions.

In this embodiment, the panel is formed in continuous lengths from sheet steel. The sheet steel may be provided with coloured surfaces or may simply be galvanised.

As seen in the profile or end view of the embodiment, each edge is formed with a substantially channel-shaped portion. On one edge is formed an inner locking edge portion or inner edge portion 11 and on the other adjacent edge is formed an outer locking edge portion or outer edge portion 12 .

The panel is formed with a central stiffening rib 14, and a plurality of stiffening channels 15. The stiffening rib 14 is substantially U-shaped in cross-section, but it will be seen that the base portion of the stiffening rib 14 is formed such that the sheet material is brought together along the length of the stiffening rib 14, and that the portions of the panel 14a are formed with the same cross-sectional shape as the adjacent stiffening channels 15. When viewed from underneath, the lower portions 14a of the stiffening rib 14 will have the same appearance as the adjacent stiffening channels 15.

As can be seen from the end view, the outer edge portion 12 is formed so that some deformation of the channel is required to engage the inner edge portion 11. The outer edge portion 12 must elastically deform about or adjacent to the edge 16, and the force associated with this deformation will also cause the inner edge portion 11 to likewise deform resulting in elastic deformation about or adjacent to edge 17. The extent of deformation of both the inner and outer edge portions 11 and 12 will be within the elastic range, and as the surface 18 of the outer edge portion 12 passes over the edge 17 of the inner edge portion 11, the outer edge portion 12 will clip and lock to the inner edge portion 11.

As can be seen in the embodiment, both the inner and outer edge portions 11, 12 are formed with a vertical surface portion 20, and an angled surface portion 21. The inner and outer edge portions 11 and 12 are formed such that the vertical surfaces 20 of adjacent sheets abut, so that when viewed from beneath the assembled panels, the angled surface portions 21 have a cross-sectional shape similar to the stiffening channels 15. Therefore, it will be difficult to discern any difference between the stiffening rib 14, the join line between adjacent panels and the stiffening ribs 15. This will result in a more aesthetically pleasing appearance.

In addition, it will be seen from Fig. 3 that when assembled, the inner and outer edge portions 11 and 12 have a substantially symmetrical cross-section about a central vertical axis y-y extending between the abutting panels.

There may still be minor variations in shape between the inner and outer edge portions 11 and 12 which result in a slight asymmetry however it is possible to vary the distribution of material such that the shear centre 25 is at least located over the central vertical axis y-y. This thereby avoids any torsional forces resulting from shear loading across the joint, which in turn reduces buckling and the tendency to unclip the inner and outer edge portions 11 and 12.

From a brief consideration of the above detail, it will be clear that the invention provides an improved panel profile with increased strength characteristics, and in addition the possibility of having improved appearance of the assembled panels when viewed from underneath. 245

Claims (6)

WHAT WE CLAIM IS:

1. A panel having complementary locking edge portions arranged on two of the opposed edges of the panel and stiffening channels formed in the panel between said locking edge portions and extending parallel to said edge portions, said locking edge portions comprising an exterior locking edge portion on one said edge of the panel having a channel-shaped cross-section, and an interior locking edge portion on the opposed edge of the panel having a channel-shaped cross-section that can locate within the exterior locking edge portion of an adjacent similar panel such that the interior locking edge portion is held with respect to the exterior locking edge portion so that substantially upright abutment surfaces of said locking edge portions of said adjacent panels abut, the interlocking interior and exterior edge portions of adjacent panels forming a cross-sectional shape which is substantially symmetric about a vertical axis that extends between the cooperating abutment surfaces of adjacent panels, and said abutment surfaces extend adjacent to further surfaces which cooperate to form a channel having substantially the same cross-sectional shape as said stiffening channels.

2. A panel according to claim 1 wherein the interior and exterior edge portions are shaped so that when said panel is attached to an adjacent similar panel, the interlocked interior and exterior edge portions have a cross-sectional shape with a shear centre that is substantially contiguous with the centroid of the cross-section.

3. A panel according to any one of the preceding claims wherein the channel of the exterior locking edge portion is shaped to elastically deform when it is forced over the interior locking edge portion of an adjacent similar panel, the interior and exterior locking edge portions being shaped so that said exterior edge portion locks onto said intej^jSr^r edge portion. j/ 7

4. A panel according to any one of the preceding claims further comprising a stiffening rib formed between the interior and exterior locking edge portions, said rib having substantially the same cross-sectional shape as the cross-sectional shape of said interlocked interior and exterior locking edge portions.

5. A panel according to any one of the preceding claims wherein the stiffening channels have an inverted V-shape in cross-section, and the further surface of each locking edge portion is an angled surface that extends along the length of each said panel edge and extends upwardly from a substantially horizontal surface portion of said panel and the upright abutment surface that extends along the length of each said panel edge extends substantially vertically from the upper edge of said angled surface, said interior and exterior locking edge portions extending upwardly from the opposite edge of the respective vertical abutment surface, said vertical abutment surfaces of adjacent panels abutting when attached so that the two angled surfaces form an inverted V-shape channel in cross-section.

6. A panel substantially as herein before described with reference to and as illustrated in the accompanying drawings. STRATCO (AUSTRALIA) PTY LIMITED By their Attorneys JAMES & WELLS - 8 "