WO1998004841A1

WO1998004841A1 - Joiner clip for sheet materials

Info

Publication number: WO1998004841A1
Application number: PCT/NZ1997/000095
Authority: WO
Inventors: Carl Dozell
Original assignee: Doz-Lock Limited
Priority date: 1996-07-25
Filing date: 1997-07-24
Publication date: 1998-02-05
Also published as: AU3560397A

Abstract

The invention comprises a joiner for joining sheet materials, preferably those where joints have a plastered finish. Typical uses include the installation of wall and ceiling linings. The joiner comprises at least two sheet engaging portions, each able to accommodate an inserted edge portion of a sheet. Use of a joiner helps brace and stiffen joints and addresses problems where sheets cannot be joined over a supporting backing member such as a stud or batten.

Description

JOINER CLIP FOR SHEET MATERIALS TECHNICAL FIELD

The present invention is directed primarily to joiners for use in conjunction with sheet materials Preferred embodiments will be used in conjunction with sheet material such as gypsum and plaster type board, where a plaster finish is typically applied over the joins

BACKGROUND ART

While the present invention may find use joining virtually any sheet mateπal, for simplicity of description reference shall be made to the most commonly used sheeting material in many western countries - a gypsum based material named Gibraltar board (or as it is more commonly known in New Zealand - Gib ™ board), often known as Sheetrock™ or Drywall™ overseas

Gibraltar board is commonly used as a wall lining, and more often also a ceiling lining in buildings It is generally supplied in a sheet form of varying lengths and nailed directly to studs or battens In the past, sheets were affixed to walls in a vertical manner, extending from floor to ceiling The longest two edges, which are typically tapered and will be subsequently plastered over, are typically positioned to overlap a stud Wherever possible, joins between sheet material are made over solid elements, such as studs or battens, so as to avoid unwanted flexing (such as if a joint were to be suspended between solid construction elements) with subsequent cracking of the plaster finish

With the growing trend towards paint finishes, fixing practice has altered to lessen the number of joins so as to reduce the amount of plastering The current practice is now to fix sheets horizontally with each sheet extending the full length of the wall where possible For this technique it is no longer possible to rely on the vertical studs to support the entire edge of a horizontally affixed sheet To counter this problem it is necessary to provide some form of solid packing behind the edges, the most appropriate choice being a nog or dwang extending between adjacent studs While these are, by necessity, provided in most wall framing, requirements for timber based construction may only require the use of nogs or dwangs at centres which do not coincide with the 1200 mm width of most sheeting mateπal. Accordingly it is necessary for the builder to cut a new set of nogs and nail these in place before attaching the sheeting material.

As can be appreciated, cutting and fitting new nogs can be relatively time consuming and expensive In addition, these new nogs have no other purpose other than acting as a packer for supporting the edge of the sheet material i e they are not otherwise structurally required To date the applicant, with considerable experience in the building industry, is not aware of any solution to this problem.

Further, timber framing is but one facet of building construction Quite often steel or metal framing is relied upon, particularly in commercial establishments However, once again the necessity of inserting horizontal members to act as a backing support for edges of sheet material may be required.

Problems may also arise when sheets are affixed vertically For instance, walls are not always multiples of stud spacings, and ceilings are not always multiples of batten spacings Accordingly, it may be necessary to trim sheets so as to fall over available studs or battens when in fact there may be less wastage if the joins were positioned between the supporting members For ceilings, even if the builder is able to coincide the edges of sheet mateπal with available battens, occasionally the length of the room exceeds maximum available sheet lengths In these situations joins between the ends of sheet material may also need to be made In most constructions battens run in one direction only, with no cross battens Accordingly, for a good joint, it would be desirable for cross-wise nogs between battens to be inserted, which is a tedious and difficult job, to the extent that quite often it is neglected

A further area, which the present invention may often address, is a difficulty associated with fixing sheet material to ceilings Quite often this is a two person job, requiring two people to raise and support the sheet material until it can be fixed into place Because of the flexibility of the sheets, it can be difficult to ensure that the sheet being fixed butts neatly with the previously fixed sheet or edge Unless there are three persons, each of the two persons can only judge how accurately they have butted the sheets from a position along the centre line of the sheet, which is awkward and inaccurate given the tendency for the edge portions to bow downwardly Typically, a sheet is best manoeuvred into a position thought to be appropriate, and a nail or other fixing means driven into the sheet near its middle or wherever the person happens to be located If the sheet is not too large, or if additional people are available, a nail or other fixing means may first be driven into the edge adjacent to the previously affixed sheet This is a preferred position to begin nailing as it also allows the builder to ensure that the gap between adjacent sheets is appropriate, and their edges parallel

In practice, however, this can only be achieved through use of small sheets, by the use of props (which are not an entirely acceptable solution) or by nailing a block of wood adjacent the edge of the previously affixed sheet so as to form a lip into which the new sheet can be temporarily inserted and held until fixed in place However, this latter option is an additional step which also damages the surface of the previously affixed sheet.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided a joiner for sheet materials, said joiner comprising at least two sheet engaging portions each comprising a base portion separating two substantially parallel wall portions to form a channel of substantially U-shaped appearance for accommodating the edge portion of a sheet therebetween; each of said two sheet engaging portions being connected and disposed such that its channel opens to face in different directions.

According to a further aspect of the present invention there is provided a joiner for sheet materials comprising: at least one sheet engaging portion for each sheet to be joined, the joiner accommodating for at least two sheets entering the joiner from different directions; each sheet engaging portion comprising two wall portions which lie in substantially parallel planes, and which are spaced apart to accept a portion of the edge of a sheet therebetween.

According to another aspect of the present invention there is provided a joiner substantially as described above in which there is provided either or both of apertures or slots in a wall portion.

According to another aspect of the present invention there is provided a joiner substantially as described above in which the wall portions of a sheet engaging portion provide a grip on a sheet inserted between same.

According to another aspect of the present invention there is provided a joiner substantially as described above in which said grip is achieved by at least one of: inwardly directed barbs or protrusions on the wall portion; - an inward bias on a wall portion; roughening or texturing the inside of a wall portion or part thereof, and having a gripping insert intermediate a wall portion and inserted sheet. According to another aspect of the present invention there is provided a joiner substantially as described above in which in which sheet engaging portions for different sheets open in substantially 180° opposite directions to each other.

According to another aspect of the present invention there is provided a joiner substantially as described above in which in which two sheet engaging portions for different sheets are back-to-back adjacent

According to another aspect of the present invention there is provided a joiner substantially as described above which is adapted to engage three or more sheets

According to another aspect of the present invention there is provided a joiner substantially as described above in which the mouth edge of a wall portion is flared outwardly to aid sheet insertion into the sheet engaging portion to which the wall portion belongs

According to another aspect of the present invention there is provided a joiner substantially as described above in which in which there is provided more than one sheet engaging portion for interacting with a single sheet

According to another aspect of the present invention there is provided a joiner substantially as described above which is formed of a flame retardant mateπal

According to a further aspect of the present invention there is provided a stπp of joiners, each substantially as described above, comprising substantially a single piece with weakened joins between each joiner allowing for the separation of a joiner or group of joiners from the remainder of the stπp without damage to the joiners sufficient to impair their function

According to yet a further aspect of the present invention there is provided a modified joiner assembly comprising two joiners, each substantially as described above, separated by a spacing member

According to another aspect of the present invention there is provided a joiner assembly, substantially as described above, in which said spacing member is able to maintain said joiners in a substantially matching oπentation

According to yet a further aspect of the present invention there is provided a method of joining sheets of material comprising the use of a joiner substantially as described above, wherein an edge of each sheet to be joined is inserted into said joiner, and wherein said joiner helps maintain said sheets in position at least near their joined edges and with respect to movement perpendicular to their plane According to yet a further aspect of the present invention there is provided a method of substantially hollow wall or partition construction comprising the use of joiner assemblies, substantially as described above, in which sheets of suitable lining or construction material are used to form the walls, with said joiner assemblies being used to join the edges of adjacent sheets on a wall face, and wherein the spacing member of the joiner assembly spaces the sheets of each wall face apart by the desired distance.

According to a further aspect of the present invention there is provided a method of joining sheet materials comprising the use of a joiner having at least two sheet engaging portions directed in different directions, said joiner being substantially rigid; said method including inserting the edges of said sheet materials within the sheet engaging portions of said joiner and completing fixing of said sheet materials to the surface to which they are to be attached.

The present invention will generally be used for joining the edges of two sheets of material, though it is possible that other embodiments may be used for the joining of three or more sheets. While this will add to the complexity of the design, the general principles will remain the same. Simplified embodiments of the present invention may also attach to the edge of only one sheet of material, the primary use of such embodiments being to protect or stiffen the edge of the sheet.

For simplicity of description, reference will only be made to embodiments which connect or join two sheets of materials. The principles embodied in these joiners may also be applied to more complex or alternative designs.

Most embodiments will comprise at least two sheet engaging portions which are able to accommodate the edge of a sheet of material. Each sheet engaging portion will be disposed so as to accommodate one of the two sheets being joined. Embodiments having three or more sheet engaging portions, and where two or more sheet engaging portions accommodate edges of the same sheet of material, are also envisaged.

A number of different configurations may be adopted by sheet engaging portions. As most sheet materials being joined, such as Gibraltar board, are typically substantially flat and planar, a sheet engaging portion which is channel-like or substantially U-shaped in cross section, is preferred. However, other configurations may also be employed.

One aim of the sheet engaging portion is to help maintain the accommodated edge of the sheet material in a fixed position with respect to the joiner. As the different sheet engaging portions in a joiner are fixed with respect to each other, the edges of all sheets accommodated by a joiner will therefore be held in a fixed position relative to each other. This maybe within a single plane, at a particular angle, or even offset. The configuration of the sheet engaging portion will be dependent upon a number of factors. One factor is the method of construction- often it is preferable to avoid complicated or expensive manufacturing techniques unless some advantage or feature outweighs the effort and expense. Further, the nature of the material being joined will also affect the configuration of the sheet engaging portions.

For instance, sheet materials such as Gibraltar board are not highly resistant to impact or localised force, especially near their edges where the ability to distribute this force over surrounding material is diminished. Accordingly, a joiner whose sheet engaging portions only grasps a small surface area of the sheet will not be particularly desirable unless a large number of such sheet engaging portions are provided in a joiner, or where a number of joiners are used in relation to joining the sheets, or where there is already present a backing material to support the sheets in the vicinity of their edges (in which case the joiner will be used more as a locating element rather than being relied upon as the primary means for conferring strength in the vicinity of the edges). In preferred embodiments of joiners, the sheet engaging portion is substantially channellike and will typically comprise a base portion separating two wall portions. Typically these wall portions will be substantially parallel, though they may be slightly directed towards each other so as to provide some pressure on the edge of an inserted sheet. The outer most edges (typically the 'mouth' of the sheet engaging means) of the side wall portions in these embodiments, as well as others, may be radiused or slightly rounded, or outwardly flared or diverging to aid insertion of an edge, and also to prevent damage to same.

Where tapered edge sheet materials are being joined, perfectly parallel side wall portions may be sufficient to provide pressure against the sheet material if this is required. In some embodiments, the substantially parallel wall portions may diverge slightly outwardly.

Preferably the sheet engaging portions should contact a reasonable surface area of the sheet material. This will be determined by the amount of force to which the sheet may be subjected, or theoretical forces which the joint is required to be able to withstand, as well as the composition of the sheet materials themselves. Various embodiments of the present invention may therefore be adapted to accommodate such requirements. As a typical example for joining Gibraltar board in a situation where joins are not backed by a continuous solid support, each side wall portion is substantially rectangular and thus a sheet engaging portion is substantially channel-like in appearance. Reference is also made to the preferred description of the invention, later herein. In an alternative arrangement, the side wall portions may be relatively small though a joiner would provide a plurality of such sheet engaging portions for each sheet of mateπal. Again reference is made to embodiments described in more detail, later herein.

In other embodiments the wall portion for one side of the sheet may be larger than for the other.

Further modifications may be made to the sheet engaging portions to improve the integrity of any resulting join. For instance, features which increase the grip on an inserted edge have been briefly discussed. Other modifications include inwardly directed barbs and features which may even penetrate sheets of softer materials. Such features may be provided to interact with one face of inserted sheet material only or both faces. These may be provided on all, or only some of the provided sheet engaging means.

Ribs, roughened surfaces, and other types of texturing and featuring may also be employed to increase grip Positionable inserts intermediate between the sheet engaging portion and the sheet mateπal may also be used. These may be part of the sheet engaging portιon(e.g. a lining or insert of a different material) or inserted at the time of sheet insertion These inserts may also confer other properties such as vibration damping (for sound proofing applications) or thermal resistance, etc

In many instances the joiner will not be visible when the sheets have been joined and appropriately finished In some instances it is possible that the joiner may be visible, in which case a suitably attractive or camouflaged finish may be applied to visible and exposed portions. It is also possible that a separate attachable cover piece may be provided, which may interact with one or more features of the joiner units for attachment or clipping.

However in most embodiments it is envisaged that a plaster type finish will be applied to finish any joint between the sheet materials. In such systems the joiner will typically be concealed under the finishing layer of plaster or stopping material

In many instances the preferred stopping mateπal is a water based plaster which may have difficulty in adhering to a smooth surface. When additives or stopping systems able to bind to the surface of the jomer are not used, it is typically desirable to provide some feature or modification enabling the stopping material to key in, or at least contact the surface of the sheet mateπal (to which it may adhere) in the vicinity of the sheet engaging portions In a prefeπed embodiment a number of slots and/or apertures are provided to enable the preferred water based plaster stopping to penetrate through the apertures and adhere to the outer surface of the sheet mateπal. This also helps maintain the sheet engaging portion in position with respect to the sheet mateπal, especially where no barbs or other edge holding features are provided.

Other modifications include cross hatching, roughening, and various other texturing modifications to enhance the grip of the stopping material with the portions of the joiner which it will contact. Surface coatings and primers may also be applied in addition to, or as an alternative to, any roughening or textuπng.

Typically such modifications will be made to the outer surfaces of the side wall portions, or at least to that side wall portion which will be on the exposed or stopped face.

Other modifications may be made such as the provision of apertures through which fastening means may pass In some instances joiners may be used in conjunction with, or overlapping, backing supports such as studs, nogs or battens for supporting the sheet Indeed, the present invention may be used where solid packing is provided, for the purposes of locating and helping to maintain in perfect register the edges of the sheet material (where the framing may not be truly straight or square) as well as strengthening the join, and straightening the edge (so as to move out any waves or ripples due to inadequacies in the framing or supports). It is possible that such joiners may be of extended length, and could conceivably extend a substantial proportion of the length of the edges of the sheet materials

The relative positioning of the sheet engaging portions also waπants discussion. In most applications, adjacent sheets to be joined are co-planar and thus channel-like sheet engaging members will open out in 180° opposite directions In other embodiments, this angle may differ, typically between 10° - 180° to allow joining of sheet mateπals at angled intersections e g internal and external corners However, for simplicity, reference shall be made to coplanar aπangements such as is common in the middle of a wall Oppositely directed channels (or other angled arrangements) may be placed back to back though this may be difficult to fabricate except for moulded, extruded or injected embodiments A preferred embodiment is fashioned from flat sheet material, and relies on portions being folded appropriately. Here is it easier to offset the sheet engaging portions so that they are adjacent when travelling lengthwise along the joiner. Where more than two sheet engaging portions are provided, the engaging portions for opposite sheets may be alternated along the length of the joiner.

For some fire rated systems, it is necessary to have double thicknesses of sheet materials.

Here multiple side by side sheet engaging portions may be provided, in addition to any lengthwise distribution of the sheet engaging portions. Furthermore, the bases of the sheet engaging portions (which are side by side rather than lengthwise adjacent )may be offset as is required by construction methods for many fire walls. However, it is envisaged that in many instances it may be easier to rely on separate joiners for each thickness of sheet material applied to the wall.

A further modification is for use of the joiners in creating partitions and walls of sheet materials. Here two joiners, to be used for connecting sheets on alternate faces of the partition, are connected by a spacing member distancing them by the required distance for the thickness of the partition. The spacing member is preferably attached so that it cannot be readily separated from the joiners, especially when in place in a constructed partition.

Spacing members may simply be a rod, tube, or folded strip of a material such as metal, which is resistant to compression. It may be attached to the joiners to assist in maintaining them in a matched or preferred relative orientation to one another.

In use, the joiner assemblies thus described would be used in conjunction with sheets of material to construct a partition. Other intermediate spacing assemblies (e.g. packers etc) may also be placed between sheets in their mid-sections. Pre-constructed panels of the coπect thickness for the partition may be used, with the edges of the face sheet materials extending past any central packing to be engageable by the joiner assemblies.

BRIEF DESCRIPTION OF DRA WINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a perspective diagrammatic view of first preferred embodiment of the present invention;

Figure 2 is a side diagrammatic view of an alternative embodiment of the present invention; Figure 3 is an end cross sectional diagrammatic view of a third embodiment of the present invention;

Fi ure 4 is an end cross sectional diagrammatic view of one method of use of the embodiment of Figures 1 through 3;

Figure 5 is an end diagrammatic view of yet a further embodiment of the present invention;

Figure 6 is an end diagrammatic view of yet a further embodiment of the present invention for joining non-tapered sheet edges; Figure 7 is a perspective view yet a further embodiment of the present invention, and

Figure 8 are end views of stiffened embodiments of the present invention

Figure 9 is a perspective diagrammatic view of a prefeπed embodiment of a joiner assembly

BEST M ODES FOR CARRYING OUT THE INVENTION

Example 1

With reference to the drawings and by way of example only there is provided a joiner, (generally indicated by arrow 1 ) for sheet material (2,3) comprising at least two sheet engaging portions (4,5), each comprising a base portion (6 7), separating two substantially parallel wall portions (8,8a/9,9a) which are tn the illustrated example, substantially perpendicular to the base (6,7) to form substantially a channel of U-shaped appearance, each of the two sheet engaging portions (4,5) being connected and disposed such that the channels' openings face in different directions Figure 1 illustrates a first preferred embodiment of the present invention This is preferably manufactured from a sheet mateπal such as 0 55mm thick galvanised steel stπp A number of keying apertures (10) are provided in the side wall portions (8, 8a, 9, 9a) to allow stopping mateπal to penetrate through and contact a face of inserted sheet material (2) A number of nailing apertures ( 1 1 ) are also provided in the side wall portions These may not be used in every situation, in which case they act as additional apertures for keying of the stopping material.

Indentations ( 12) are also provided to act as barbs for improved gripping of the inserted sheet mateπal (2) These barbs (12) may be provided near the edge, or further down the side walls as is apparent in Figure 3 After the modifications to the side walls have been completed, they may then be folded and fashioned into the arrangements of Figure 1

If necessary, the number of sheet engaging portions ( 1 , 4) may be increased and continuously alternated - (reference is made to a dotted outline 14) representing an optional continuation of the jo er (1) Example 2

Figure 2 illustrates an alternative embodiment of a joiner (20) In many respects this joiner is similar to the joiner (1 ) of Figure 1 However, the length of the side walls (21, 22) of each sheet engaging portion (23, 24) is substantially shorter in length Because of the decreased length, apertures for keying in a stopping material are not provided and instead a roughened or textured finish to the outer faces of the exposed side walls (21, 22) are provided. In the illustrated embodiments fastening apertures (25) are provided and may also act as keys for stopping material, if not used for fastening. Example 3

Figure 3 illustrates a further embodiment of a joiner (30) in which the sheet engaging portions (31, 32) are positioned back to back rather than being alternated along the length of the joiner. In this embodiment the engaging portions (31 , 32) are fashioned separately and then connected back to back through their base portions (33, 34). Different fastening methods may be relied upon to connect bases though in the illustration a rivet (35) has been relied upon.

As an alternative, injection moulding methods could be relied upon to produce a single unit of the general cross sectional configuration shown in Figure 3. It should be envisaged however that other fabrication techniques may be relied upon. Also visible in the embodiment of Figure 3 are the addition of barbs (36) which are substantially unidirectional and help grip an inserted sheet of material. A further modification is the slightly upturned outer lip (37) on the outer edge of one of the side walls (38) in each engaging portion (31, 32). These (37) aid insertion of sheet material and could be provided on all side walls. However, by providing the upturned lips (37) on only one side wall (38) in each engaging portion (31 ,32) the joiner (30) may be readily reversed so that the lip portion is present on the exposed outer face, or on the hidden inner face, of a resulting join.

Example 4

Figure 4 illustrates one method of use of a joiner such as shown in any one of Figures 1 through 3. Here the joiner (40) is shown already attached to one sheet of material (2). This sheet (2) has already been fastened to a batten (41 ) or other supporting member.

This second sheet of material (3) can then be inserted edgewise into the open engaging portion (42) before being fixed to the second visible batten or supporting member (43). Where the battens (41, 43) are ceiling battens, then the advantage of the joiner (40) supporting the inserted edge (44) of the second sheet of material (3) until it can be subsequently fastened to a batten (43), is clearly evident.

Once fixing has been completed, stopping material may be then applied (see arrows 45) to cover the joiner (40) and finish the joint. Example 5

Figure 5 illustrates an alternative embodiment of the present invention which may be used for internal or external corners. Here the joiner (50) may be fashioned in the same manner as embodiment of Figure 1 , though with some of the side wall (51, 52) being bent at a greater angle so that they are no longer substantially perpendicular to their base portion. Shown is an inserted sheet of material (53), while the second sheet (54) has yet to be inserted

Example 6

Figure 6 illustrates a modified joiner 60 which may be used for joining non-tapered edges of sheet material which will be subsequently stopped. Here there is a slight angle (61) between the edge engaging portions (62, 63) which causes the edge portions of the sheet to flex inwardly This creates a small V-shaped hollow (64) which allows stopping material (65) to be applied over the hollow (64) but still have a perfectly flush finish. Typically the angle (61 ) will be between 0.5°-5° though may he outside of this range. Factors influencing the angle include the flexibility of the sheet materials, and the distance from the nearest supporting stud or batten (66).

Example 7

Figure 7 illustrates a further embodiment of the present invention and which comprises a modification of the embodiment of Figure 1. The main notable difference is that in the Figure 7 embodiment (70) one of the walls (72) is greater in height from the base (72) than the opposing wall (73) This provides an increased backing area (typically the higher wall (71 , 71a) will be positioned to the rear) to support the rear of a sheet It is envisaged that this is likely to be more commonly used for ceilings where flexing or sagging can be more noticeable than on a vertical wall However this does not preclude this clips (70) use for other applications.

Example 8

Figures 8a and 8b illustrate further variations (80, 81 ) of the invention. In these embodiments the rear face (82, 83) has been stiffened through the use of ribs (84, 85), channels (86) or other rearwardly extending features (87). These rearwardly extending features (84 - 87) extend out of the general plane of the wall sections (82 - 83) and help stiffen the clip (80, 81) against forward or rearward flexing.

In Figure 8a, a hollow box-like section (87) has been formed by rolling over the top of the rear face (82). In contrast, Figure 8b illustrates an embodiment where a separate member (85) has been fastened (88, 88a) to the rear face (83). In addition, the top portion of the rear face (83) has been rolled back to form a rib (84).

As can be appreciated many other means of providing additional stiffening on the rear face may be employed. For instance, the rear face may be formed into other configurations, such as through the provision of creases, folds, etc. to form a variety of different stiffening arrangements. One or more lengthwise creases provided in the rear walls is but one possibility.

Another variation is to attach additional stiffening elements, such as is used in Figure 8b. These additional elements may be of virtually any size, shape or configuration and may be attached in any convenient manner, including riveting, welding, adhesive fixing, etc. Combinations of the various techniques are also possible.

It is also possible that additional stiffening may be provided on the front faces (89) of the clips though generally these types of stiffening will be relatively shallow, especially if a finished plaster, or filler, surface is to be applied over the joint. It is possible that any such stiffening may be inwardly, and inwardly directed creases could not only stiffen the front face (89) but also improve grip on an inserted sheet.

Example 9

Figure 9, illustrates a joiner assembly (99) according to the present invention. Here two joiners (90, 91 ) are maintained apart by a spacing member (92). This may comprise a tube of metal riveted (9 ) at its ends to maintain the joiners (90, 91 ) in place.

The joiner assembly (99) will be generally attached to the edges of sheets (94, 95) in the construction of a partition. It may also be used in conjunction with pre-assembled partition panels having other packers/spacers (96) between the sheets (94, 95).

Example 10 Tests were performed on sheets joined by joiners according to the present invention in which there were two sheet engaging means - one for each sheet, which was a gypsum based core, paper lined product. The back wall portion was slightly higher (from the base portion) than the front wall portion. The dimension of the back wall portion was approximately 18mm (h) x 44mm (1). Two joiners were used along the length of a 2400mm sheet, positioned at approximately at the one quarter, and three quarter positions. These were compared with sheets joined without the jointers. In both cases joints were covered with paper tape, plastered with a suitable jointing compound, and finished with a finishing compound. The test comprised swinging a 50kg soft body impact bag against the test specimen. Impacts of 12J separation in magnitude were used. The trials indicated that for a direct- on-join impact, a clipped specimen was able to sustain a 25J impact without any damage, compared to 12J for an undipped specimen - at 25J the undipped specimen showed a crack and ridge of approximately 175mm length, while this first became evident in the clipped specimen at 37J. At higher impacts the joint integrity of clipped specimen was maintained until a much higher level - 98J before rupturing - as compared to 61J where there was tearing of the paper tape. The clips apparently were able to maintain joint integrity until the sheets themselves failed due to the impact. There were similar results for off -joint impacts though the improvements were not as pronounced, presumably because deflection of the sheet also served to pull the sheets apart.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

THE CLAIMS DEFINING THE INVENTION ARE:

1 . A joiner for sheet materials, said joiner comprising at least two sheet engaging portions each comprising a base portion separating two substantially parallel wall portions to form a channel of substantially U-shaped appearance for accommodating the edge portion of a sheet therebetween; each of said two sheet engaging portions being connected and disposed such that its channel opens to face in different directions.

2. A joiner for sheet materials comprising: at least one sheet engaging portion for each sheet to be joined, the joiner accommodating for at least two sheets entering the joiner from different directions; each sheet engaging portion comprising two wall portions which lie in substantially parallel planes, and which are spaced apart to accept a portion of the edge of a sheet therebetween.

3. A joiner as claimed in either claim 1 or claim 2, in which there is provided either or both apertures or slots in a wall portion.

4. A joiner as claimed in claim 3 in which said apertures and slots are configured to provide for either or both of the keying of a jointing compound applied over the joiner, or allowing a fastener to pass therethrough.

5. A joiner as claimed in any one of the preceding claims in which the wall portions of a sheet engaging portion provide a grip on a sheet inserted between same.

6. A joiner as claimed in claim 5 in which said grip is achieved by at least one of: inwardly directed barbs or protrusions on the wall portion; an inward bias on a wall portion; roughening or texturing the inside of a wall portion or part thereof, and having a gripping insert intermediate a wall portion and inserted sheet.

7. A joiner as claimed in any one of the preceding claims in which the wall portions of a sheet engaging portion are staggered along the length of the sheet engaging portion.

8. A joiner as claimed in any one of the preceding claims in which sheet engaging portions for different sheets open in substantially 180° opposite directions to each other.

9. A joiner as claimed in any one claims 1 through 7 in which sheet engaging portions for different sheets open in directions substantially 10° - 180° (inclusive) to each other.

10. A joiner as claimed in any one of the preceding claims in which sheet engaging portions facing in different directions at least partially overlap when said joiner is viewed from the side.

1 1 . A joiner as claimed in claim 10 in which two sheet engaging portions for different sheets are back-to-back adjacent.

12. A joiner as claimed in any of claims 1 through 10 which are adapted to engage three or more sheets.

1 3. A joiner as claimed in any one of the preceding claims in which the mouth edge of a wall portion is flared outwardly to aid sheet insertion into the sheet engaging portion to which the wall portion belongs.

14. A joiner as claimed in any one of the preceding claims in which there is provided more than one sheet engaging portion for interacting with a single sheet.

15. A joiner as claimed in claim 14 in which multiple sheet engaging portions for a single sheet are separated by a sheet engaging portion for another sheet.

1 6. A joiner as claimed in any one of the preceding claims formed of metal.

1 7. A joiner as claimed in claim 16, which is formed from a strip or sheet of material folded into shape.

1 8. A joiner as claimed in any one of the preceding claims formed of a flame retardant material.

19. A joiner as claimed in any one of the preceding claims which includes an isolating portion intermediate at least one wall portion and an inserted sheet, said isolating portion providing at least one of the following functions: thermal resistance between sheet and joiner; vibration resistance between sheet and joiner, and sound deadening.

20. A strip of joiners, each as claimed in any one of claims 1 through 19, comprising substantially a single piece with weakened joins between each joiner allowing for the separation of a joiner or group of joiners from the remainder of the strip without damage to the joiners sufficient to impair their function.

21 . A modified joiner assembly comprising two joiners, each as claimed in any one of claims 1 through 19, separated by a spacing member.

22. A modified joiner assembly as claimed in claim 21 in which said spacing member is able to maintain said joiners in a substantially matching orientation.

23. The method of joining sheets of material comprising the use of a joiner as claimed in any one of claims 1 through 19, wherein an edge of each sheet to be joined is inserted into said joiner, and wherein said joiner helps maintain said sheets position at least near their joined edges and with respect to movement perpendicular to their plane.

24. The method of claim 23 which also includes the step of fastening said sheets to a support to limit separation of the sheets at their join

25. The method of claim 24 in which fastening means are passed through a said joiner.

26 The method of any one of claims 23 through 25 which includes covering of the sheet join and joiner with a suitable jointing material.

27 The method of any one of claims 23 through 26 wherein the sheets are mineral based sheet materials such as used for claddings or linings.

28 The method of any one of claims 23 through 27 for the installation of wall and/or ceiling linings

29 The method of claim 28 in which the joins between sheets are positioned not to be positioned over a stud or other supporting member travelling substantially the length of the join

30. A method of substantially hollow wall or partition construction comprising the use of joiner assemblies as claimed in either claim 21 or claim 22 in which sheets of suitable lining or construction material are used to form the walls, with said joiner assemblies being used to join the edges of adjacent sheets on a wall face, and wherein the spacing member of the joiner assembly spaces the sheets of each wall face apart by the desired distance

3 1 A wall or partition constructed according to the method of claim 30

32. A wall or ceiling which has been lined according to the method of any one of claims 23 through 29

33 The use of a joiner as claimed in any one of claims 1 through 19 for the installation of wall or ceiling linings of sheet materials.

34 A joiner, substantially as herein descπbed with reference to the accompanying drawings.

35. A strip of joiners, substantially as herein described with reference to the accompanying drawings.

36 A joiner assembly, substantially as herein described with reference to the accompanying drawings.