WO2009036501A1

WO2009036501A1 - An assembly system

Info

Publication number: WO2009036501A1
Application number: PCT/AU2008/001379
Authority: WO
Inventors: Allan Holland
Original assignee: Allan Holland
Priority date: 2007-09-19
Filing date: 2008-09-17
Publication date: 2009-03-26

Abstract

An assembly system to enable a sheet member (for instance a fibre cement sheet member) can be attached relative to a support (for instance a bearer or joist), the assembly system comprising (a) a first member adapted to be attached to the support and (b) a second member adapted to be attached to the first member and, in the process, also attaching the sheet member relative to the support.

Description

An Assembly System Field of the Invention

This invention is directed to an assembly system that can attach sheet material (for instance fibre cement sheets) to a framework (for instance a joist or bearer) and in a manner that can greatly reduce the number of screws that have hitherto been required. The invention may also be directed to an assembly system that can overcome a disadvantage with leaking- especially in wet areas (for instance an outdoor deck, shower recess etc). The invention may also be directed to an assembly system that can allow LVL (laminated veneer lumber) product to be used in wet areas. The invention is particularly directed to an assembly system that can overcome all or at least most of the above disadvantages.

Background Art

Compressed fibre cement sheeting (FC sheeting) is manufactured from

Portland cement, finely ground silica, cellulose fibres and water. After forming, it is compressed to a high density then cured in a high pressure steam autoclave to create a durable, dimensionally stable product. It is immune to permanent damage from water, is impact resistant, immune to termite attack, non combustible and easy to work.

The sheeting is commoniy used as a substrate for floors in wet areas of framed constructions, but there are other uses as well including wall cladding, a substrate for laying tiles, and the like.

The two main thickness of FC sheeting are:

15.0mm Compressed - High density fibre cement sheet suited for substrate floors in wet areas, external decks, upper stories and transportable buildings of framed construction, and for spanning floor joists of 450mm centres.

18.0mm Compressed - High density fibre cement sheet suited for substrate floors in wet areas, external decks, upper stories and transportable buildings of framed construction and for spanning floor joists of 600mm centres.

The rectangular sheets have a length of between 1500mm - 3000mm and a width of between 900mm - 1200mm As mentioned above, one common use for these sheets is as a substrate under tiles and in a framed construction. As an example, it is sometimes required to have an outdoor deck containing tiles and it is not possible to lay the tiles directly on to the decking floor. Instead, fibre cement sheets are nailed to the joists to form a substrate floor. A plastic liner is laid on top of the fibre cement sheets. The plastic liner typically comprises reinforced polyethylene having a thickness of about 1.5 mm.

A mortar bed is then spread on top of the plastic liner and the mortar bed will typically have a thickness of between 5-20 mm. The tiles can then be laid onto/into the mortar bed. This technique is well-known. The plastic membrane is there to prevent water from leaking underneath the flooring. Thus, this type of construction is particularly suited if there is a storage area or living area or other area underneath the flooring which is to stay dry. This type of construction can also be used in an upper storey of a multi-storey framed house to prevent water from leaking through the ceiling of the lower floor.

One major disadvantage with this existing system is that about 200 nails/screws are required to attach a single FC sheet having a length of 2400 mm and a width of 1200 mm. There would be an advantage if it were possible to attach sheets together (typically fibre cement sheets as described above) and which does not require a large number of screws to do so.

Another disadvantage with this existing system is that it is not uncommon for there to be some movement between the fibre cement sheets. This movement can cause the plastic liner to fail thereby allowing water to penetrate below. There would be an advantage if it were possible to design the modified system which would reduce this from happening.

In many framed constructions, the bearers or joists can be formed from a particular type of product called LVL. LVL stands for Laminated Veneer Lumber, and basically comprises multiple lengths of thinner wood which are glued together to form a bearer or joist. While this material is a good building product, it suffers from the disadvantage that it must not get wet. Thus, LVL products have not found particular suitability in wet areas. It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

Obj ect of the Invention

It is an object of the invention to provide an assembly system that may overcome at least some of the above-mentioned disadvantages or provide a builder with a useful or commercial choice.

In one form, the invention resides in an assembly system to enable a sheet member (for instance a fibre cement sheet member) to be attached relative to a support (for instance a bearer or joist), the assembly system comprising (a) a first member adapted to be attached to the support and (b) a second member adapted to be attached to the first member and, in the process, also attaching the sheet member relative to the support. As an example only, the first member can be the central member 27 illustrated in figure 1, and a close-up of the first member is illustrated in figure 2 and figure 3, and a side view of the first member attached to a wooden joist 13 is illustrated in figure 8. Again, as an example only, the second member can be a locking bar 15 as illustrated in figure 6 and figure 7, and positioning of the second member relative to the first member can be as illustrated in figure 8. Of course, it is not considered that any unnecessary limitation should be placed on the invention merely by illustrating this example of the invention.

In a more particular form the first member may comprise an elongate member having a first part adapted to be attached to the support (which will typically comprise a frame member) and at least one (and preferably more) second parts extending from the first part and adapted, in use, to extend between the edges of adjacent sheet members which have been placed to be closely spaced apart, and the second member can be pushed into locking engagement with, or otherwise attached to, the first member and, in doing so, also clamps or otherwise attaches each of the adjacent sheet members relative to the support.

If the support comprises a frame member, the first part is typically attached thereto by fasteners such as nails or screws. As an example only, a pair of sheet members (e.g. 11, 12 in figure 5) can be positioned onto a joist or bearer with the edges closely spaced apart with the first member being nailed to the joist or bearer, and the extending second part of the first member ( e.g. 19) being positioned between the spaced apart sheet members. The second member (e.g. 15) can comprise a locking bar or something similar which can be somewhat T-shaped in configuration (see for instance figure 6), and when this is hammered or otherwise pressed into place (see figure 7 and figure 8) tightly clamps each sheet member against the joist (see figure 8) and at the same time is engaged to the first member such that the second member cannot be removed easily. Thus, fibre cement sheets (example only) can be attached relative to joists in a manner that is secure and that does not require a multitude of screws to do so. The sheets can be used as a flooring substrate, as wall panels, or for any other suitable use.

Although the assembly system will be generally described with reference to fibre cement sheets attached to a frame member, it is not envisaged that any particular limitation should be placed on the invention merely by this desirable use and the assembly system may be used to attach other types of sheet members or planks and the like to a substrate which may comprise framework, but which may also comprise a concrete floor, a metal beam, purlin, section and the like. It is not envisaged that any particular limitation should be placed on the type of sheet member. The sheet member preferably comprises a fibre cement sheet member as these have traditionally been time-consuming and difficult to fix in place, but there may also be advantages in using the system according to the invention to attach other types of sheet members, panels and the like which may be made of wood, plastic, metal, composite materials, WPC material (wood plastic composite), insulated material, sound deadening material, and the like.

The sheet member will typically be substantially rectangular (which is common in the building trade) but there may be circumstances where the sheet member has a different configuration such as a triangular shape, a polygonal shape, or even an oval, circular or semicircular shape.

The assembly system will typically be able to attach any number of sheet members in place without requiring a large number of fasteners such as nails or screws and therefore the assembly system can be ideal for a large substrate system such as an outdoor deck- where it is necessary to provide protection underneath the deck. Thus, the assembly system can be used to attach between 2 - 100 (or even more) sheet members to a frame/substrate/etc. Each sheet member will typically have a size that enables the sheet member to be manhandled and therefore it is expected that the sheet member will have a length of between 1-4 m, a width of between 0.5 -3 m and a suitable thickness (typically between 10-30 mm) to provide strength to the sheet member .

The support will typically comprise a frame member. The frame member will typically comprise some array of bearers and joists which is traditional in respect of flooring or some array of posts and noggins which is typical in respect of wall framing. The framing may be made of wood, LVL, metal or anything else which is convenient or used in the building trade, or something else.

It is also envisaged that the support may comprise a solid floor (such as a concrete slab) or a solid wall (such as a concrete wall typically used in a tilt up construction), or a block wall, or a brick wall and the like.

The first member is the member which is adapted for attachment to the support. The type of attachment will depend on the type of support. For instance, if the support comprises a bearer or joist made of wood or something similar, the attachment can be done by nails or screws. Alternatively, if the support comprises a metal purlin or metal section, the attachment can be achieved using metal screws or even spot welding.

For some very large jobs, it is also envisaged that the assembly system may have some purpose manufactured supports formed with the first member either already attached or formed integrally thereto. This may be particularly the case if the specially manufactured support is a metal purlin or C or Z section or something similar.

The first member may be elongate and will typically be long enough to enable it to fasten several sheet members. It is envisaged that the first member will have a length of between 0 .5 - 3 m, although this can vary to suit. For instance, the assembly system may comprise a larger number of shorter members or a fewer number of larger members. It is envisaged that, if necessary, the first member can be cut to length.

The first member can be made of any suitable material. However, for strength and robustness, it is considered that the first member will typically be made of metal and sheet steel (especially galvanised) is considered to be an excellent choice for the manufacture of the first member. The sheet steel can have a thickness of between 0 .5 - 2 mm.

The first member will typically have a first part which is adapted to be attached to the support. The first member will then also typically comprise a second part that extends from the first part. The first part and the second part may be formed integrally with the remainder of the first member and can be punched out or bent out of the first member especially if the first member is made of galvanised sheets steel, or extruded. However, each part may also be formed separately and attached by any suitable means such as by welding, use of fasteners, adhesive and the like.

The first part will typically be designed and configured to form a secure attachment to the support. If the support comprises a joist (see for instance figure 8), the first part may comprise a U-shaped section/channel shaped section or an L-shaped section that can extend over the top and at least one side wall (L-shaped section) or both sidewalls (U-shaped section) of the joist. The U-shaped version is illustrated in figure 8. An advantage of this is that the top of the joist can be completely covered and protected against ingress of moisture which can create rot etc.. Although the illustration of the first member in figure 1 (the central member) illustrates the top wall being formed with openings, it is envisaged that the first member can also have a completely continuous top wall if desired. Another advantage of this arrangement is that the joist can be made of

LVL (laminated veneer lumber) with the top and sides of the LVL joist being completely protected by the first part and therefore making the LVL suitable for use in wet areas where previously it has not been recommended to use LVL.

However, it is also envisaged that the first part may simply comprise a top plate (that is without any sidewalls) and this particular variation may find suitability if the substrate comprises a metal section (for instance a C-section).

As mentioned previously, the first part can be nailed, screwed, welded or otherwise attached relative to the support. If the support comprises a concrete slab, concrete nails or concrete fasteners can be used. It is also envisaged (especially for large jobs) that the first part may be cast into the concrete prior to the concrete curing.

The first member has a second part that can extend from the first part. The second part will typically be positioned, in use, adjacent an edge of a sheet member and if a pair of sheet members is bought together, the second part will typically extend between the edges. It is preferred that the second part does not extend above the sheet member such that the top of the sheet members have a neat flush finish. However, if a layer of grout is subsequently placed on top of the sheet members to attach tiles, the second part may extend somewhat proud, and possibly partially into the layoff grout.

The height of the second part will therefore be somewhat dependent on the thickness of the sheet member. For instance, if the sheet member has a thickness of 15 mm or 18 mm, it is preferred that the height of the second part is about the same or slightly less.

The second part may extend upwardly or outwardly from the first part and will typically extend substantially at right angles relative to the first part. However, there may be circumstances where the second part may extend outwardly at an angle other than a right angle. The second part may comprise a single elongate flange/wall etc extending substantially or entirely along the top of the first part. Alternatively, the second part may comprise a number of upwardly extending shorter sections which may comprise "tabs" or something similar these being particularly illustrated in figure 2 and figure 3 as reference numeral 20. If a number of shorter sections is provided, these may be regularly spaced along the top of the first part or irregularly spaced along the top of the first part.

It is preferred that a plurality of second parts is provided which are spaced apart sufficiently to allow the second member (see for instance figure 6) to be inserted between the second parts. The pair of second parts may be identical or different to each other. The spacing may depend on the thickness of the portion of the second member that passes between the pair of second parts and, as an example, the spacing may be between 5 mm - 10 mm. It is also envisaged that the second part, instead of comprising a pair of spaced apart sections, may comprise a single member containing some form of recess to capture and hold the portion of the second member that passes into this recess. The recess may be provided with some form of capture mechanism which may comprise a number of teeth, ribs, and the like which can engage with something similar that may be provided on the second member. The single member may comprise a single elongate member that extends along the first part or, may comprise a plurality of separate members which may be spaced regularly or irregularly on the first member.

A second member (e.g. 15) is provided which can engage with the first member and in the process attach the sheet member relative to the support. The second member may comprise a locking bar or something similar. An example of a locking bar is illustrated in figure 6, figure 7 and figure 8 but this is an example only and is not meant to be limiting to the invention. The locking bar may comprise an elongate member and it is preferred that the locking bar has some length to provide a neat finish to the top of the sheet members. Thus, the locking bar may have a length of between 0 .5 -3 m or even longer or shorter and can be cut to length if required etc.

The locking bar should be made of strong material and therefore it is envisaged that the locking bar will be made of metal such as aluminium. An advantage of aluminium is that the locking bar can be extruded to the desired shape in a relatively inexpensive manner. Alternatively, there may be certain circumstances where the locking bar can be made of strong plastic or composite materials and the like.

The locking bar will typically have a first portion adapted to engage with the first member, and at least one second portion which is adapted to engage with the sheet member. The at least one second portion may comprise a laterally extending portion which is adapted to overlie the top wall of the sheet member and adjacent the edge of the sheet member (see figure 8) such that when the locking bar is attached, the sheet member will be clamped relative to the joist.

Adhesive may be provided to further secure the sheets in place. It is envisaged that the locking bar will have the laterally extending portion adjacent each side of the first portion and, in a particularly preferred embodiment, the locking bar may have a somewhat T-shaped configuration as illustrated in figure 6. However, there may be circumstances where the locking bar will have a different shape.

For instance, the laterally extending portion may comprise at least one or plurality of fingers or tabs and the like which extend over the top of the sheet member. If desired, the at least one second portion may include some form of tooth or something else that can cut into the top of the sheet member to more tightly hold the sheet member in place.

The second member is adapted to engage with the first member and thereby also hold the at least one sheet member in place. Preferably, the second member is pushed or hammered into position and, in the process, is also locked to the first member. In a particularly preferred non-limiting embodiment, the second member engages against at least one projection or tooth on the first member which locks the second member to the first member. The projection on the first member may extend from the second part of the first member and there may be provided a projection extending from one side or both sides of the second part.

For further attachment security, the second member (e.g. locking bar) may be provided with a tooth or rib or groove or something else to better engage with the projection or tooth on the first member. It is also envisaged that this may be reversed and the first member may be provided with a groove, a rib, a recess and the like and the second member may be provided with a corresponding projection or tooth that can engage with the first member to hold the two members together.

In another form, the invention may reside in a better way to waterproof a floor or something similar. An embodiment of this invention is illustrated in figure 10 with figure 9 illustrates in the conventional PRIOR ART way. To explain, and initially referring to figure 9, a waterproof membrane is placed on top of the sheet members but the waterproof membrane can be damaged by normal movement between the sheet members. In the embodiment of this form of the invention (illustrated in figure 10) this can be reduced by having the waterproof membrane extending about the joists and not over the top of the sheet members. This will be explained in greater detail below.

Brief Description of the Drawings Embodiments of the invention will be described with reference to the following drawings in which:.

Figure 1. Illustrates three wooden joists each containing a cover member with the middle joist containing a first member according to an embodiment of the invention.

Figure 2. Illustrates in close up a pair of the second parts that extend from the first member.

Figure 3. Illustrates the same pair of second parts but from a different angle.

Figure 4. Illustrates a fibre cement sheet member pushed against one side of the second part of the first member.

Figure 5. Illustrates a second fibre cement sheet pushed against the other side of the second part of the first member and spaced apart from the first fibre cement sheet to form a small gap.

Figure 6. Illustrates the second member (locking bar). Figure 7. Illustrates the second member roughly positioned in place in the small gap formed between the adjacent fibre cement sheets illustrated in figure 5.

Figure 8. Illustrates an edge view showing the second member about to be hammered into position to lock against the first member thereby clamping the adjacent fibre cement sheets in place. Figure 9. Illustrates a conventional PRIOR ART arrangement of forming a tiled floor on a wooden framework.

Figure 10. Illustrates a different way of forming a tiled floor on a wooden framework with the main difference being the repositioning of the waterproof membrane.

Best Mode Referring to the illustrations, most of the features of the embodiment can be seen in figure 8. Referring to figure 8, there is described an assembly system to enable a sheet member (in this case a first fibre cement sheet member 11 and adjacent second sheet member 12) to be attached to a support which, in the embodiment, comprises a wooden joist 13. The assembly system comprises a first member 14 and a second member 15 with the second member 15 being illustrated by itself in figure 6.

Referring now in greater detail to the first member 14, the first member 14 has a first part 16 which is substantially U-shaped and which therefore comprises a top wall 17 and opposed sidewalls 18. First part 16 is formed from galvanised sheet metal which is bent into the desired configuration. By being substantially U-shaped, the first part 16 neatly sits over the top of the joist 13 and protects the top wall and each sidewall of the joist. Therefore, joist 13 can also be formed from laminated veneer lumber (LVL) as the shape of the first part protects against any water ingress into the LVL. The first part 16 can be nailed or screwed to the side of joist 13 by side fixing which means that the nails or screws pass through these sidewalls 18 of the first part and into the sidewalls of the joist. An advantage of this is that top fixing can sometimes split the joist and can create a site for water to slowly work its way into the joist, therefore making LVL not very suitable. Extending from top wall 17 of first part 16 is an array of spaced pairs of spaced apart second parts 19. The second parts 19 are better illustrated in figure 2 and figure 3 and comprise spaced apart metal tabs 20 which are somewhat rectangular. The tabs can be welded or otherwise attached to the top wall or may be punched out or bent out of the top wall. The tabs 20 have a length of about 30 mm - 60 mm and a height which is such that the top of the tabs sit at or below the top wall of the sheet members 11, 12 (see for instance figure 8). Thus, if the sheet member has a thickness of say 15 mm, the height of each tab will be 15 mm or slightly less.

The tabs 20 are spaced along the top wall 17 of the first part 16 this being illustrated in figure 1 where the centre member contains the first member 14. Each tab 20 (see particularly figure 2 and figure 3) contains extending teeth 21 extending particularly on the inside wall of each tab such that the teeth point towards each other between the adjacent pair of tabs. In the particular embodiment, the teeth 21 also extend on the other face of each tab 20.

Referring to figure 4, one of the sheet members 11 can be laid on top of the joist 13 such that the edge of the sheet member is pushed against the tabs 20. Then, an adjacent sheet member 12 (see figure 5 and figure 8) can be placed against the other side of tabs 20. The teeth 21 may press partially into each edge of each sheet member.

The second member 15 (see figure 6, figure 7 and figure 8) comprises a locking bar and is substantially T- shaped and therefore comprises a depending central wall 22 (see figure 6), and a pair of upper laterally extending walls 23, 24 (which in the preferred embodiment actually comprises a single wall). The second member 15 is positioned such that the depending wall 22 is between the pair of spaced apart extending tabs 20 (see particularly figure 8) which means that the laterally extending walls 23, 24 extends over the upper of each sheet member 11, 12 (see particularly figure 8 but also figure 7). The locking bar is made of extruded aluminium.

At this stage, the second member (locking bar) can be pushed or hammered downwardly. As this occurs, the central wall 22 of the locking bar is gouged by the inwardly extending teeth 21 on each tab 20 as the harder steel teeth will gouge into the softer aluminium. Consequently, the locking bar is securely locked in position by the teeth 21. In a variation, the central wall 22 may be formed with a groove or a rib to facilitate engagements against the teeth. When the locking bar is pushed downwardly, the top part of the T section will clamp against the top wall of each sheet member 11, 12 and will tightly clamp the sheet members in position. ' In practice, (and see figure 1), a number of joists 26 - 28 may be provided with joist 26 and 28 being nothing more than a cover member while joist 29 contains the upwardly extending tabs 20 as the sheet members 11 will have the edges positioned on joist 27.

Referring in somewhat greater detail to joist 26 and^' 28, it can be seen that the joists contain a U-shaped cover member , where the top wall 29 comprises spaced apart regular arrays of small projecting buttons or nipples 30. These nipples 30 provide an indication as to where the adhesive is to be placed such that the sheet members can be securely glued onto each metal U-shaped cover member. In practice, adhesive is placed between the nipples 30 and extending from one pair of nipples 30 to the adjacent pair of nipples 30. Not only does this allow adhesive to be quickly applied, it also ensures that the correct amount and spacing of adhesive is followed to ensure that the sheet members are properly glued to the respective cover member. The U-shaped cover members that are attached to joist 26 and 28 can be nailed or screwed by side fixing in a manner similar or identical to that described with reference to joist 27.

In use, a substrate floor can be more easily provided using any number of sheet members 11, 12 and with a greatly reduced number of fasteners. Instead, the sheet members can be glued. The edges of the sheet members can be securely camped by the system described above (using the first member 14 and the second member 15). It is envisaged that there will be a clamping system around all the relevant edges of each sheet member. Referring now to figure 9 and figure 10, these illustrate schematically laying of a tiled floor onto a framed construction. Figure 9 illustrates^' the conventional technique. In this conventional technique, joists 31, 32 are placed in position and fibre cement sheets 33, 34 are placed on the joists (although not illustrated in figure 9 the opposed edges of the sheets 33, 34 will usually be positioned on a single joist rather than between a pair of joists as illustrated in figure 9). On top of the sheets 33, 34 is laid a waterproof liner 35 which comprises a conventional polyethylene sheet having a thickness of about 1.5 mm.. A layer of grout 36 is placed on top of the sheet 35 and tiles 37 are then laid on the grout. A disadvantage with this system is that any movement of the sheet members 33, 34 can cause tearing of the liner 35 which allows water to penetrate through the sheets.

Referring now to figure 10, joists 31, 32 are initially fitted with the waterproof liner 35 and a U-shaped metal cover 36A is then placed about each joist and sandwiches the waterproof liner. The sheets 33, 34, grout 36 and tiles 37 can then be applied/ laid on the normal manner. With this improvement, there is less likelihood of the liner 35 tearing.

Throughout the specification and the claims (if present), unless the context requires otherwise, the term "comprise", or variations such as "comprises" or "comprising", will be understood to apply the inclusion of the stated integer or group of integers but not the exclusion of any other integer or group of integers. Throughout the specification and claims (if present), unless the context requires otherwise, the term "substantially" or "about" will be understood to not be limited to the value for the range qualified by the terms.

Claims

1. An assembly system to enable at least one sheet member to be attached relative to a support, the assembly system comprising (a) a first member adapted to be attached to the support and having a first portion adapted to be attached to the support and to support the edges of the adjacent sheet members and at least one second portion extending from the first portion and adapted, in use, to extend between the edges of adjacent sheet members closely spaced apart and (b) a second member adapted to be attached to the first member and, in the process, also attaching the sheet member relative to the support.

2. An assembly system as claimed in claim 1 and adapted to attach adjacent sheet members relative to the support wherein the first member includes an elongate member and the second member engaged with the first member and, in doing so, clamping each of the adjacent sheet members relative to the support.

3. An assembly system as claimed in claim 1 or claim 2 wherein the first part is attached to the support by fasteners such as nails or screws.

4. An assembly system as claimed in any one of the preceding claims wherein the second portion is formed integrally with the first portion and punched out then bent to stand proud of the first portion.

5. An assembly system as claimed in any one of claims 1 to 3 wherein the first member is extruded with the second portion standing proud of the first portion.

6. An assembly system as claimed in any one of the preceding claims wherein the first portion includes a U-shaped section/channel shaped section that can extend over the top and both sidewalls of a support.

7. An assembly system as claimed in any one of claims 1 to 5 wherein the first portion includes an L-shaped section that can extend over the top and at least one side wall of a support.

8. An assembly system as claimed in any one of claims 1 to 5 wherein the first portion includes top plate that can extend over the top of a support.

9. An assembly system as claimed in any one of the preceding claims wherein the first portion is provided with a plurality of openings adapted to receive fasteners therethrough to attach the first portion to the support.

10. An assembly system as claimed in any one of the preceding claims wherein the height of the second portion is less than the thickness of the sheet member.

11. An assembly system as claimed in any one of the preceding claims wherein the second part includes at least one pair of extending tabs between which a portion of the second member is received.

12. An assembly system as claimed in claim 11 wherein at least a pair of second portions is provided spaced apart sufficiently to form a recess to allow a portion of the second member to be inserted between the pair of second portions.

13. An assembly system as claimed in any one of claims 1 to 10 wherein the second portion includes a recess to capture and hold a portion of the second member that passes into this recess.

14. An assembly system as claimed in claim 12 or claim 13 wherein the recess is provided with a capture mechanism and the second member provided with a corresponding mechanism to engage with the capture mechanism of the recess.

15. An assembly system as claimed in any one of the preceding claims wherein the second member has a first portion adapted to engage with the first member, and at least one second portion which is adapted to engage with the sheet member.

16. An assembly system as claimed in claim 11 wherein the at least one second portion of the second member includes a laterally extending portion adapted to overlie an outer surface of the sheet member adjacent an edge of the sheet member such that when the second member is attached to the first member, the sheet member is clamped relative to the support.

17. An assembly system as claimed in any one of the preceding claims wherein the second member has a T-shaped configuration.

18. An assembly system as claimed in any one of the preceding claims wherein the second member is pushed or hammered into position and, in the process, is locked to the first member.

19. An assembly system as claimed in any one of the preceding claims wherein at least one projection is provided on the second member and the first member to lock the second member to the first member.

20. An assembly system as claimed in any one of the preceding claims wherein adhesive is provided to further secure the sheet members in place.