WO2007012137A1

WO2007012137A1 - Interlocking members

Info

Publication number: WO2007012137A1
Application number: PCT/AU2006/001063
Authority: WO
Inventors: Shaun Nolan
Original assignee: Grandbay Holdings Pty Ltd
Priority date: 2005-07-28
Filing date: 2006-07-28
Publication date: 2007-02-01
Also published as: US20080216435A1; CA2616611A1; EP1913214A1

Abstract

A member such as a board (10) configured to interlock with similar such boards, typically for use as flooring. The board (10) comprises an elongate body (11) having first and second opposed faces (13, 15) and two longitudinal sides (17, 19). A first locking portion (12) is provided at one longitudinal side (17) and a second locking portion (22) is provided at the other longitudinal side (19). The first locking portion (21) comprises a tongue (23) presenting a convex face (33), and the second locking portion (22) comprises a groove (41) for receiving the tongue (23) of a similar board disposed adjacent thereto. The groove (41) has a face incorporating a concave portion (49) for receiving the convex face (33) of the tongue (23), whereby interaction between the convex and concave portions (33, 49) serves to draw the tongue (23) of one board into the groove (41) of another board upon relative angular movement between the two boards towards a position whereby they are in side-by-side relation. The first locking portion (21) further comprises a first interlocking element configured as a further groove (38) disposed between the tongue (23) and the second face (15) of the body (11). Additionally, the second locking portion (22) further comprises a second interlocking element configured as a rib (61) disposed between the groove (41) and the second face (15) of the body (11). The rib (61) and groove (38) of adjacent boards are adapted to interlock when the two boards are in side-by-side relation.

Description

"Interlocking Members"

Field of the Invention

This invention relates to coupling for interlocking two members and also to members incorporating such couplings. The invention is concerned particularly, although not solely, with a coupling for interlocking boards, as well as with a board configured to interlock with another similar such board.

The invention has been devised particularly, although again not necessarily solely, as a board for flooring, and also as a board for cladding for walls (both interior and exterior walls) and ceilings as well as partitioning.

Background Art

Floor boards of the tongue-and-groove type are well known. Such boards are assembled to provide strip flooring by fitting boards together, involving installing one board in position and then sliding a neighbouring board laterally into position so that the tongue of one board engages in the groove of the other board. The boards can be fixed in position in any suitable way, typically by nailing and/or gluing.

Tongue-and-groove flooring is advantageous in that the connection between neighbouring floor boards accommodates relative movement arising through expansion and shrinkage of the boards. A further advantage of tongue-and- groove flooring is that the floor boards can be made from any appropriate timber, including hardwoods and soft woods. This allows the floor boards to be of solid (one-piece) construction, configured as planks of timber.

There is, however, a deficiency with tongue-and-groove flooring in that shrinkage of the floor boards can result in unsightly gaps between the boards. Further, the boards can warp, providing a "cupping" effect which again can be unsightly. In recent times, there has been a trend towards flooring systems involving panels that can be interlocked. The panels may be fixed in portion in any suitable way, typically by nailing, gluing and/or floating between. Typically, such panels are of composite construction, comprising a core and a laminate applied to the core to provide a robust yet decorative floor surface. Typically, the core is made of a relatively soft material such as MDF, HDF or the like. The panels are adapted to interlock, with each panel being provided with an interlocking male portion configured as a tongue and a matching interlocking female portion configured as a groove. The arrangement is such that the panels can be interlocked one to another with a snap action to resist lateral separation between the panels (which could otherwise lead to unsightly gaps). Such panels do, however, rely upon the relative softness of the core material in which the female portion is formed, to yield to allow entry of the respective male portion for locking engagement therewith. For this reason, the panels need to be of the composite construction incorporating the soft core, and cannot be of solid (one-piece) timber.

It would be advantageous for there to be a board which can interlock with a corresponding board without the boards necessarily having to be of composite construction incorporating softer core material.

Disclosure of the Invention

According to a first aspect of the invention there is provided a coupling for interlocking two members each having first and second opposed faces, the coupling comprising a first locking portion provided on one member and a second locking portion provided on the other member, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a section presenting a convex face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion, the female portion having a face incorporating a concave section for receiving the convex face of the male portion, whereby interaction between the convex face and concave section serves to draw the male portion into the female portion upon relative angular movement between the two members towards an interlocked position, and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the first member, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the second member, the first and second interlocking elements being adapted to interlock when the two members are in the interlocked condition.

Preferably, the convex face is asymmetrical to thereby define a cam surface. The convex face may comprise a plurality of segments disposed angularly one with respect to another. The section of the male portion presenting the convex face may comprise a lobe.

According to a second aspect of the invention there is provided a member comprising an elongate body having first and second opposed faces and two longitudinal sides, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a section presenting a convex face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar member disposed adjacent thereto, the female portion having a face incorporating a concave section for receiving the convex face of the male portion, whereby interaction between the convex face and concave section serves to draw the male portion of one member into the female portion of another member upon relative angular movement between the two members towards a position whereby they are in side-by-side relation and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the body, the first and second interlocking elements of adjacent members being adapted to interlock when the two boards are in side-by-side relation.

According to a third aspect of the invention there is provided a board comprising an elongate body having first and second opposed faces and two longitudinal sides, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a section presenting a convex face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar board disposed adjacent thereto, the female portion having a face incorporating a concave section for receiving the convex face of the male portion, whereby interaction between the convex face and concave section serves to draw the male portion of one board into the female portion of another board upon relative angular movement between the two boards towards a position whereby they are in side- by-side relation and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the body, the first and second interlocking elements of adjacent boards being adapted to interlock when the two boards are in side-by-side relation.

Preferably, the first face has two opposed edges from which the longitudinal sides extend at respective junctions therebetween.

Preferably, said relative angular movement between the boards is about a fulcrum defined by engagement between one junction of one board and the adjacent junction of the other board,

Preferably, the first surface of the board presents an exposed surface, which in the case of a floor board would be the upper surface and in the case of cladding would be the visible surface.

Preferably, the section presenting the convex face extends towards the first face.

Preferably, the section presenting the convex face is provided on the side of the male portion closer to the first face of the board, and the concave section is provided in the side of the female portion closer to the first face.

The section presenting the convex face comprises a plurality of segments disposed one adjacent another. In this way, the section presents a multi-faceted surface. The multi-faceted surface may have a camming effect as it interacts with the concave section to draw the male portion into the female portion.

Preferably, the first and second interlocking elements define two interlocking surfaces adapted to co-operate for frictional engagement therebetween to provide an interlocking action.

The first and second interlocking elements preferably comprise a further groove defining one of the interlocking surfaces and a matching rib defining the other of the interlocking surfaces, the rib being adapted to be snugly received in the further groove with the two interlocking surfaces in frictional engagement.

Preferably, the first interlocking element comprises the further groove and the second interlocking element comprises the rib, the further groove being located adjacent and parallel to the male portion and the rib being located adjacent and parallel to the female portion.

The first locking portion may further comprise a first abutment face extending from the first face and a second abutment face extending from the second face, the male portion extending outwardly from the two abutment faces. The second abutment face may be offset inwardly with respect to the first abutment face.

The second locking portion may further comprise a third abutment face extending from the first face and a fourth abutment face extending from the second face, the female portion extending inwardly from the two abutment faces. The fourth abutment face may be offset with respect to the third abutment face in the outward direction.

With this arrangement, when two boards according to the invention are interconnected, the respective first and third abutment faces, and also the respective second and fourth abutment faces, are in abutting relationship.

Preferably, the first and second interlocking elements provide engagement between abutting second and fourth abutment faces of interlocking boards. Preferably, the male portion and female portion are configured to define one or more voids therebetween. The voids are useful in accommodating variations in the dimensional characteristics of the male and female portions and for also accommodating any excess glue used for the purposes of gluing the male portion into position in the female portion.

The second locking portion may incorporate a channel to receive fastening elements such as nails, staples or the like. Additionally, or alternatively, the channel may receive an adhesive, such as a "wet glue".

The interlocking connection between the boards may accommodate some angular misalignment between adjoining boards (such as in circumstances which the substrate on which the boards are installed is not entirely level) without adversely affecting the interlocking action. Such misalignment may comprise both positive curvature and negative curvature.

This may be accomplished by provision of raking on one of the longitudinal sides adjacent the first face. Further, there may also be raking on a section of the side of the groove adjacent the second face, said section being adjacent the open end of the groove.

Weather guard strips, which can be either fixed or removable, may also be provided.

According to a fourth aspect of the invention there is provided a member comprising an elongate body having first and second opposed faces and two longitudinal sides, the first face having two opposed edges from which the longitudinal sides extend at respective junctions therebetween, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion comprising a lobe section presenting a cam face extending towards the first face and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar member disposed adjacent thereto, the female portion having a face incorporating a receiving portion for receiving the lobe section of the male portion, whereby interaction between the cam face and the receiving portion serves to draw the male portion of one member into the female portion of another member upon relative angular movement between the two members towards a position whereby they are in side-by-side relation, said relative angular movement being about a fulcrum defined by engagement between one junction of one member and the adjacent junction of the other member, and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the body, the first and second interlocking elements of adjacent boards being adapted to interlock when the two members are in side-by-side relation.

According to a fifth aspect of the invention there is provided a member comprising an elongate body having first and second opposed faces and two longitudinal sides, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a lobe section presenting a cam face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar member disposed adjacent thereto, the female portion having a face incorporating a receiving section for receiving the cam face of the male portion, whereby interaction between the cam face and receiving section serves to draw the male portion of one member into the female portion of another member upon relative angular movement between the two members towards a position whereby they are in side-by-side relation, and wherein the cam face comprises a plurality of segments disposed one adjacent another.

According to a sixth aspect of the invention there is provided a coupling for interlocking two members each having first and second opposed faces, the coupling comprising a first locking portion provided on one member and a second locking portion provided on the other member, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a lobe section presenting a cam face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion, the female portion having a face incorporating a receiving section for receiving the cam face of the male portion, whereby interaction between the cam face and receiving section serves to draw the male portion into the female portion upon relative angular movement between the two members towards an interlocked position, and wherein the cam face comprises a plurality of segments disposed angularly one adjacent another.

Brief Description of the Drawings

The invention will be better understood by reference to the following description of specific embodiments thereof as shown in the accompanying drawings in which:

Figure 1 is an end view of a floor board according to a first embodiment;

Figure 2 is a fragmentary view (on an enlarged scale) of a first longitudinal side of the floor board;

Figure 3 is a fragmentary view (on an enlarged scale) of a second longitudinal side of the floor board;

Figure 4 is a fragmentary perspective view illustrating a floor boards according to the embodiment being positioned for locking connection one to the other;

Figure 5 is an underside perspective view of the arrangement shown in

Figure 4;

Figure 6 is a fragmentary perspective view illustrating the two floor boards in the interlocked condition;

Figures 7 to 11 are a series of schematic end views illustrating two floor boards according to the embodiment undergoing interconnection; Figures 12 to 16 are fragmentary views showing on a larger scale the interconnections between the two floor boards illustrated in Figures 7 to 11 ;

Figure 17 is a fragmentary view (on an enlarged scale) of the interconnection between the two floor boards;

Figure 18 is a fragmentary view of a first longitudinal side of a floor board according to a second embodiment;

Figure 19 is a fragmentary view of a second longitudinal side of the floor board according to the second embodiment;

Figure 20 is a view similar to Figure 18 but with several angles identified;

Figure 21 is a view similar to Figure 19 but with a further angle identified;

Figure 22 is a fragmentary view of the tongue on the first longitudinal side, illustrated on an enlarged scale;

Figure 23 is a fragmentary view of the interconnection between two floor boards according to the second embodiment;

Figure 24 is a view similar to Figure 23, with the exception that there is a positive curvature between the two interconnected floor boards;

Figure 25 is also a view similar to Figure 23, with the exception that there is a negative curvature between the two interconnected floor boards;

Figure 26 is an end view of a floor board according to a third embodiment;

Figure 27 is a fragmentary view (on an enlarged scale) of a first longitudinal side of the floor board according to the third embodiment;

Figure 28 is a fragmentary view (on an enlarged scale) of a second longitudinal side of the floor board according to the third embodiment; and Figure 29 is an end view of two floor boards according to the third embodiment connected together.

Best Mode(s) for Carrying Out the Invention

The embodiments shown in the drawings are each directed to a floor board 10 configured to interlock with other similar such boards in order to provide strip flooring.

Referring to Figures 1 to 17, floor boards 10 according to the first embodiment each comprise an elongate body 11 having a first face 13, a second face 15, a first longitudinal side 17 and a second longitudinal side 19. The first face 13 and the first longitudinal side 17 intersect at junction 18. Similarly, the first face 13 and the second longitudinal side 19 intersect at junction 20.

When the floor board 10 is installed in position to provide flooring, the second face 15 is disposed downwardly (and so will hereinafter be referred to as the lower face 15) and the first face 13 is disposed upwardly to define the floor surface (and so will hereinafter be referred to as the upper face 13).

A first locking portion 21 extends along the first longitudinal side 17 of the body 11 and a second locking portion 22 extends along the second longitudinal side 19.

In this embodiment, the floor board 10 is formed of a single piece of timber, in which case the first and second locking portions 21 , 22 are integral with the body. In this regard, the floor board 10 is produced by milling (or otherwise machining) a piece of timber to form the body 11 having the upper and lower faces 13, 15 as well as the two locking portions 21 , 22.

The first locking portion 21 comprises a male portion configured as a tongue 23. The first locking portion 21 further comprises an upper abutment face 24 and a lower abutment face 25, from which the tongue 23 extends outwardly. The upper abutment face 24 extends downwardly from upper face 13, and the lower abutment face 25 extends upwardly from lower face 15. The lower abutment face 25 is offset inwardly with respect to the upper abutment face, as best seen in figure 1.

The tongue 23 has an upperside 26 and an underside 27 which merge at smooth transitional edge 29 extending longitudinally along the body 11.

The upperside 26 includes a straight section 31 and an arcuate section 33 of convex configuration. Thus the arcuate section 33 provides a lobe section presenting a convex face. The convex face is asymmetrical and as such constitutes a cam face. The straight section 31 extends from the upper abutment face 24 in a downward direction to intersect with the arcuate section 33, as shown in the drawings.

The underside 27 of the tongue 23 includes a straight section 35 and a curved section 37. The straight section 35 extends from the lower abutment face 25 to merge with the arcuate section 37 which terminates at the edge 29 where it merges smoothly with the arcuate section 33 at the transitional edge 29, as shown in the drawings.

The lower abutment face 25 at the first locking portion 21 extends downwardly from the underside 27 of the tongue 23 to the lower face 15 of the body.

The first locking portion 21 further comprises a groove 38 in the lower abutment face 25 adjacent to the underside 27 of the tongue 23. The groove 38 has a longitudinal extent parallel to the tongue 23. The groove 38 is configured as a channel having straight side sections 39 extending inwardly from the abutment face 25 and an arcuate inner end section 40. Side section 39a is co-planar with the underside 27 of the tongue 23 to merge seamlessly therewith. Side section 39b intersects with the abutment face 25 at junction 39c which is chamfered. An external locking corner 60 is defined at the intersection of side section 39b and abutment face 25.

Side section 39c defines an interlocking surface 62, the purpose of which will be explained later. The portion 25a of the lower abutment face 25 below the groove 38 is raked inwardly somewhat.

The second locking portion 22 comprises a female portion configured as a groove 41. The second locking portion 22 further comprises an upper abutment face 42 and a lower abutment face 43 from which the groove 41 extends inwardly. The lower abutment face 43 is offset outwardly with respect to the upper abutment face 42, as best seen in figure 1. The groove 41 has an upper wall 44, a lower wall 45 and an inner wall 46. The upper wall 44 of the groove 41 incorporates an outer straight section 47 extending inwardly from the upper abutment face 42, an arcuate section 49 and an inner section 51 adjacent the inner wall 46. The outer section 47 extends inwardly towards the lower wall 45, and intersects with the arcuate section 49. The inner section 51 is small in comparison to sections 47, 49 of the upper wall 44 and defines a shoulder 53 adjacent the inner wall 46.

The arcuate section 49 is of concave configuration for co-operation with the convex arcuate section 33 of the tongue, as will be explained in more detail later.

The lower wall 45 has a straight section 45a parallel to the faces 13, 15, and a convex section 45b which intersects with inner wall 46. It extends beyond the upper confines of the groove 41 as defined by the upper abutment face 42 and outwardly to the lower abutment face 43. The lower wall 45 incorporates a channel 55 extending longitudinally with respect to the body 11 , the channel 55 being located in the exposed section 57 of the lower wall 45 beyond the upper confines of the groove 41.

The lower abutment face 43 at the second locking portion 22 extends downwardly from the lower wall 45 of the groove 41 to the lower face 15 of the body.

The second locking portion 22 further comprises a rib 61 configured and dimensioned to be snugly received in the groove 38 of an adjoining board, with a void 72 defined therebetween. The rib 61 has a longitudinal extent parallel to the groove 41. The rib 61 has two straight side sections 63 and an arcuate outer end section 65. Side section 63a is co-planar with the lower wall 45 of the groove 41 to merge seamlessly therewith. Side section 63b intersects with the lower abutment face 43. An internal locking corner 70 is defined at that intersection.

Side section 63b defines a further interlocking surface 64, the purpose of which will also be explained later.

While not shown in the drawings, the junctions 18, 20 between the first face 13 and the respective upper abutment faces 24, 42 can be profiled if desired, such as by incorporation of a chamfer at each junction.

As alluded to above, the board 10 according to the embodiment is adapted to interlock with similar such boards to provide strip flooring. In this regard the first and second locking portions 21 , 22 cooperate to provide a coupling for interconnecting the boards. The manner in which the boards interlock will now be described, with reference to figures 7 to 16 of the drawings, in which two boards 10a and 10b according to the embodiment are illustrated. The description will be made with reference to board 10a already being in an installed position such that its lower face 15 is supported on a substrate (not shown). The substrate can be of any appropriate form according to the installation site. The substrate may, for example, comprise a continuous surface such as concrete or plywood panelling, or subfloor framing such as timber joists.

With floor board 10a in position with its second locking portion 22 exposed, floor board 10b is presented to floor board 10a at an angle of about 20° to the horizontal, as illustrated in figure 7. The tongue 23 of floor board 10b is inserted into the groove 41 of floor board 10a, with the arcuate section 33 of the tongue upperside 26 contacting the curved transition section 50 of the upper wall 44 of the groove 41 , and the curve section 37 of the tongue underside 27 contacting the lower wall 45 of the groove. The downward inclination of the straight section 31 on the tongue upperside 26 provides the necessary clearance with respect to the groove upper wall 44 when the floor board 10b is in the tilted condition. The two floorboards 10a, 10b are also in contact at or closely adjacent junctions 18, 20. This contact provides a fulcrum 80 about which floorboard 10b can be rotated to lock the two boards together, as will be explained below.

Floor board 10b is then progressively tilted downwardly and pushed towards floor board 10a, thereby causing the tongue 23 to slide along the upper and lower walls 44, 45 of the groove, as illustrated in figures 7 to 16. As the tongue 23 further enters the groove 41 , the convex section 33 on the tongue moves into engagement with the concave section 49 on the upper wall 44 of the groove. Cooperation between the convex section 33 of the tongue 23 and the concave section 49 of the groove 41 produces a cam effect which causes the tongue to be drawn further into the groove 41 as the floor board 10b continues to be tilted downwardly. With this arrangement, the tongue 23 and groove 41 mechanically interlock, establishing a "knuckle joint" connection therebetween.

As board 10b approaches the position where it is almost resting on the substrate, the groove 38 on floor board 10b moves into registration with the rib 61 on floor board 10a, as illustrated in figures 10 and 15. Upon movement of floor board 10b into its final position on the substrate, as illustrated in figures 11 and 16, the cam effect between the tongue 23 and the groove 41 draws the tongue fully into the groove and also draws the groove 38 into full engagement about the rib 61. Further, the external corner 60 moves into engagement with the internal comer 70, as shown in Figures 16 and 17. As the corners 60, 70 move into engagement, the interlocking surface 62 on the first locking portion 21 frictionally engages against the further interlocking surface 64 on the second locking portion 22

When the groove 38 has fully received the rib 61 , as shown in figures 11 and 16, the external comer 60 locks into the internal corner 70, with the interlocking surfaces 62, 64 in compressive engagement.

The lower abutment face 25 on floor board 10b is brought into contact with the lower abutment face 43 on floor board 10a as the tongue 23 is drawn fully into the groove 41. Similarly, the upper abutment face 24 of floor board 10b is brought into compressive contact with the upper abutment face 42 of floor board 10a. Engagement between the groove 38 and rib 61 , or more particularly the external and internal corners 60, 70, has the effect of drawing the boards 10a, 10b into planar alignment on the substrate to correct any warpage in the boards.

When the boards 10a, 10b are interlocked, the raked portion 25a of the lower abutment face 25 can co-operate with abutment face 43 to define a wedge- shaped space 71. The space 71 can accommodate some expansion and contraction between the interlocked boards, as well as accommodating some over-centring movement between the two boards without disrupting the integrity of interlocking therebetween in circumstances where the substrate on which the boards are laid is not entirely level.

The interlocking connection between the two floor boards 10a, 10b draws the boards together into abutting relationship at the respective abutment faces. Further, in the interlocking condition there are various interfaces of contact between the tongue 23 and the groove 41. Specifically, the convex section 33 on the upperside 26 of the tongue 23 is in contact with the concave section 49 of the upper wall 44 of the groove 41. Additionally, the straight section 35 of the underside 27 of the tongue 23 is in contact with the bottom wall 45 of the groove 41. Further, there is an interlocking action between comers 60, 70.

The various forces involved in establishing and maintaining the two boards in the interlocked condition will be explained with reference to Figure 17. There are three primary forces, a first acting along line X-X, a second acting along line Y-Y and a third acting along line Z-Z.

The first force, which acts along line X-X, is a compressive force established by compression between fulcrum 80 and the interlocked corners 60, 70.

The second force, which acts along line Y-Y is a tension force which holds the tongue 23 in tension within the locking groove 41. The tension arises through compressive contact between the boards at abutment faces 24, 42 and 25, 43, and engagement of the tongue 23 in groove 41 at mating arcuate sections 33, 49. The third force, which acts along line Z-Z, is a compressive force established between fulcrum 80 and contact between the tongue 23 and groove 41 at the interface between mating convex section 33 and concave section 49. The axis Z- Z is normal to a tangent at the two mating arcuate sections 33, 49.

The interlock between the two boards 10a, 10b serves to assist in transferring load (such load arising, for example, from the application of weight to the upper surface 15) from one board to the other board. Load transfer is assisted by the offset relationship between the contacting abutment faces 24, 42, a consequence of which is that the tongue underside 27 presents a significant load bearing area on the lower wall 45 of the groove 41. Load transfer is also assisted by interaction between the rib 61 and the groove 38 in which it is received, as well as compression between contacting abutment faces 24, 42 and 25, 43.

In some applications, the boards 10a and 10b (as well as other similar boards installed to provide flooring) are in a "floating" arrangement, whereby they are not fixed to the substrate and also not fixed to one another (apart from being interlocked by way of the first and second locking portions 21 , 22).

There are, however, many applications where the floor boards would be nailed to the substrate. The board 10 according to the embodiment is particularly suitable for this purpose, as the channel 55 in the exposed section 57 of the lower wall 45 of the groove 41 can receive fixings such as nails or staples, thereby allowing the boards to be nailed in place by way of a "secret fixing" process. The heads of the fixings can be accommodated entirely within the channel 55. Alternatively, the fixings may be installed such that they are slightly proud of the surface of the lower wall 45, thereby providing some frictional engagement with the tongue of the adjacent board as the tongue is being introduced into the groove. The fixings are not so proud as to prevent entry of the tongue but rather allow the tongue to enter, with the underside 27 of the tongue being scored by the heads of the fixings. This scoring action the tongue to enter the groove and also provides some frictional engagement on the tongue to assist in maintaining it in position within the groove. The channel 55 is so positioned relative to the upper abutment face 42 that the latter can be used as a guide for a gun employed to drive fixings into the floor board. The gun can be positioned against the abutment face 42 and then moved along that face, driving fixings at necessary intervals into the floor board through the channel 55.

In other applications, glue can be used in fixing the boards together. The glue can be either a "wet" glue or a "dry" glue.

If a wet glue is used to fix the boards together, the glue can be applied into the channel 55. It is particularly convenient to apply the glue into the channel 55 by way of a wiping process. Once the wet glue has been introduced into the channel 55, the tongue 23 of the next board can then be inserted and the board installed.

Where a dry glue is used, it is typically applied to both the tongue 23 and the groove 41. In this regard, a layer of dry glue is applied to the straight section 35 of the tongue underside 27 and the lower wall 45 of the groove 41 inwardly of the channel 55.

It is a particular feature of the interlocking connection between the two boards that voids exist between the tongue 23 and the groove 41 when the tongue is fully accommodated within the groove. The voids comprise void 73 defined between the junction between the lower wall 45 and the inner wall 46 of the groove 41 and also the curved section 37 of the underside 27 of the tongue. The void 73 accommodates variations in machining of the boards, and also expansion and contraction between the boards without disrupting the integrity of the interconnection therebetween, as well as accommodating any surplus glue which might be present at the interconnection following installation of the boards. The ability to accommodate surplus glue is particularly advantageous, as it prevents the surplus glue being expelled from the junction between the boards and possibly contaminating the floor surface. It also prevents any confined glue from developing a "hydraulic effect" which might either oppose full entry of the tongue 23 into the groove 41 or develop a force which might cause the tongue to partially retreat from the groove and therefore develop a gap between the interconnected boards.

In the installation process illustrated in Figures 7 to 16, the tongue 23 of the particular board 10b being laid was presented to the groove 41 of the previously- laid board 10a. However, the configuration of the first and second locking portions 21 , 22 is such that the installation process can be varied, with the groove 41 of a board being laid being presented to the tongue 23 of a previously-laid board.

Referring now to Figures 18 to 25, the floor boards 10 according to the second embodiment are each similar in many respects to the floor boards according to the first embodiment and similar reference numerals are used to identify similar parts.

It is a particular feature of the interlocking connection that it can accommodate some angular misalignment between adjoining boards in circumstances where the substrate is not entirely level, without adversely affecting the interlocking action between the boards. Where there is no angular misalignment, the angle σ defined between the first faces 13 of adjacent boards 10 is 180°, as shown in Figure 23. Where there is angular misalignment, it may comprise what is referred to as positive deviation or negative deviation. Positive deviation is angular misalignment in which the angle σ defined between the first faces 13 of adjacent boards 10 less than 180°, as shown in Figure 24. Negative deviation is angular misalignment in which the angle σ defined between the first faces 13 of adjacent boards 10 greater than 180°, as shown in Figure 25. Typically, the interlocking connection of this embodiment can accommodate positive deviation of up to 30mm over a 1 metre span and negative deviation of 15mm over a 1 metre span.

The ability to accommodate angular misalignment is provided by inward raking of the lower abutment face 25 of the first locking portion 21 as identified by angle φ in Figure 21 , and also by inward raking of the upper abutment face 42 of the second locking portion 22 as identified by angle α in Figure 20. In this embodiment, angle φ is about 15° and angle α is about 3°. Further, the lower wall 45 of the groove 41 is configured to accommodate the angular misalignment. Specifically, that section 45c of the lower wall 45 extending beyond the plane of the upper abutment face 42 is raked downwardly, as identified by angle β in Figure 20. In this embodiment, angle β is about 2°.

In this second embodiment, there are also some differences from the first embodiment in respect of the configuration of the tongue 23 and the grove 41. Specifically, in this embodiment, the lobe section 33 of the tongue 23 presents a cam surface comprising a plurality of straight segments 91 disposed in an angular arrangement, as best shown in Figure 22. In this way, the cam face comprises a plurality of facets 93 and edges 95 between adjacent facets The multi-faceted cam face presented by the lobe section 33 of the tongue 23 provides a camming effect as it interacts with section 49 of the groove 41 to draw the tongue 23 into the groove 41. The edges 95 grip against section 49 of the groove 41 during the camming action to assist in drawing the tongue 23 into the groove 41.

Further, in this embodiment, the lower wall 45 of the groove 41 has an inner section 45d which is disposed inwardly of the raked section 45c and which extends to the inner wall of the groove. The inner section 45d is substantially straight. The junction between the straight inner section 45d and the raked outer section 45c is identified in the drawings by reference numeral 45e. With is arrangement, the lower wall 45 of this embodiment does not incorporate the straight and convex sections 45a, 45b of the first embodiment. This configuration assists in accommodating angular misalignment between adjacent boards as previously described and also increases the size of void 73.

Still further, the configuration of the upper wall 44 of the grove 41 is different. Specifically, there is a flank section 48 between the outer straight section 47 and the arcuate section 49. The presence of the flank section 48 produces a void 75 which assists in accommodating expansion and contraction between the boards without disrupting the integrity of the interconnection therebetween.

Still further, in this embodiment, the area of the underside 27 of the tongue 23 where the straight section 35 merges with the curved section 37 defines a heel 36. The heel 36 contacts the lower wall 45 of the groove 41 in the region of the junction 45e when the tongue 23 is accommodated within the groove.

With this embodiment, an effective interconnection can be established between adjacent boards even in circumstances of angular misalignment involving either positive or negative curvature, as previously explained. Regardless of whether there is angular misalignment as shown in Figures 24 and 25, or no angular misalignment as shown in Figure 23, the adjacent board 10 abut at the junctions 18, 20 which define fulcrum 80 and remain in such abutment. In each case, there is contact between the interlocked boards at contact points a, b, c and d, as shown in Figures 23 to 25. Further, there is also contact at contact point e in the negative deviation condition, as shown in Figure 25. It is contact between the boards at the various contact points that provides the integrity of the interconnection.

Any expansion and contraction between the interconnected boards 10 is accommodated within the interconnection without disrupting the integrity of the interconnection. The voids 72, 73 and 75 assist in accommodating the expansion and contraction.

Referring now to Figures 26 to 29, the floor boards 10 according to the third embodiment are each similar in many respects to the floor boards according to the first embodiment and so similar reference numerals are used to identify similar parts.

In this third embodiment, the first locking portion 21 comprises a male portion configured as a tongue 23, as was the case in the first embodiment. In this embodiment, however, the first locking portion 21 does not further comprise a groove but rather a rib 101 on the lower abutment face 25 adjacent to the underside 27 of the tongue 23.

The second locking portion 22 comprises a female portion configured as a groove 41 , as was the case in the first embodiment. In this embodiment, however, the second locking portion 22 does not further comprise a rib but rather a groove 103 configured and dimensioned to be snugly the rib 101 of an adjoining board, as illustrated in Figure 29. The rib 101 and groove 103 cooperate to provide interlocking surfaces which frictionally engage, as was the case with the first embodiment.

In the embodiments described, the boards are constructed of solid timber. It should be appreciated that the boards can be of any appropriate construction, including: timber, bamboo and other natural organic materials; composite materials (such as laminate on substrate); and BSB ("bamboo strand board").

While the embodiments have been described in relation to a board for strip flooring, it should be understood that a board according to the invention may be used for various other applications, including cladding for partitioning, interior and exterior walls, and as ceiling boards.

Where boards according to the invention are used in exterior applications, there may be provision to incorporate weather seals at the junctions therebetween.

Further, the invention may have application to members other than boards. One such application may be in coupling frame elements together, such as in building trusses.

Modifications and improvements can be made without departing from the scope of the invention.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

The Claims Defining the Invention are as Follows:

1. A coupling for interlocking two members each having first and second opposed faces, the coupling comprising a first locking portion provided on one member and a second locking portion provided on the other member, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a section presenting a convex face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion, the female portion having a face incorporating a concave section for receiving the convex face of the male portion, whereby interaction between the convex face and concave section serves to draw the male portion into the female portion upon relative angular movement between the two members towards an interlocked position, and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the first member, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the second member, the first and second interlocking elements being adapted to interlock when the two members are in the interlocked condition. A board according to claim 1 wherein the first face has two opposed edges from which the longitudinal sides extend at respective junctions therebetween.

2. A coupling according to claim 1 wherein the convex face is asymmetrical to thereby define a cam surface.

3. A coupling according to claim 2 wherein the convex face comprises a plurality of segments disposed angularly one with respect to another.

4. A coupling according to claim 1 , 2 or 3 wherein the section of the male portion presenting the convex face comprises a lobe.

5. A member comprising an elongate body having first and second opposed faces and two longitudinal sides, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a section presenting a convex face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar member disposed adjacent thereto, the female portion having a face incorporating a concave section for receiving the convex face of the male portion, whereby interaction between the convex face and concave section serves to draw the male portion of one member into the female portion of another member upon relative angular movement between the two members towards a position whereby they are in side-by-side relation and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the body, the first and second interlocking elements of adjacent members being adapted to interlock when the two boards are in side-by-side relation.

6. A member according to claim 5 wherein the first face has two opposed edges from which the longitudinal sides extend at respective junctions therebetween.

7. A member according to claim 5 or 6 wherein said relative angular movement between the boards is about a fulcrum defined by engagement between one junction of one member and the adjacent junction of the other member.

8. A member according to claim 5, 6 or 7 wherein the section presenting the convex face extends towards the first face.

9. A member according to claim 8 wherein the section presenting the convex face is provided on the side of the male portion closer to the first face of the board, and the concave section is provided in the side of the female portion closer to the first face.

10. A member according to any one of claims 5 to 8 wherein the section presenting the convex face comprises a plurality of segments disposed one adjacent another.

11. A member according to claim 10 wherein the segments are disposed angularly to define facets and edges between adjacent facets

12. A member according to any one claims 5 to 11 wherein the first and second interlocking elements define two interlocking surfaces adapted to co-operate for frictional engagement therebetween to provide an interlocking action.

13. A member according to claim 12 wherein the first and second interlocking elements preferably comprise a further groove defining one of the interlocking surfaces and a matching rib defining the other of the interlocking surfaces, the rib being adapted to be snugly received in the further groove with the two interlocking surfaces in frictional engagement.

14. A member according to any one of claims 5 to 13 wherein the first locking portion further comprises a first abutment face extending from the first face and a second abutment face extending from the second face, the second abutment face being offset inwardly with respect to the first abutment face, the male portion extending outwardly from the two abutment faces.

15. A member according to claim 14 wherein the second abutment face is raked inwardly.

16. A member according to any one of claims 5 to 15 wherein the second locking portion further comprises a third abutment face extending from the first face and a fourth abutment face extending from the second face, the fourth abutment face being offset with respect to the third abutment face in the outward direction, the female portion extending inwardly from the two abutment faces.

17. A member according to claim 16 wherein the third abutment face is raked inwardly.

18. A member according to any one of claims 5 to 17 wherein the groove has a wall on the opposed side thereof to said concave section, said wall having at least a section thereof adjacent the outer end of the groove raked away from said concave section.

19. A member according to any one of wherein at least one void is defined between the tongue and the groove of two interconnected boards.

20. A board comprising an elongate body having first and second opposed faces and two longitudinal sides, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a section presenting a convex face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar board disposed adjacent thereto, the female portion having a face incorporating a concave section for receiving the convex face of the male portion, whereby interaction between the convex face and concave section serves to draw the male portion of one board into the female portion of another board upon relative angular movement between the two boards towards a position whereby they are in side-by-side relation and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the body, the first and second interlocking elements of adjacent boards being adapted to interlock when the two boards are in side-by-side relation.

21. A board comprising an elongate body having first and second opposed faces and two longitudinal sides, the first face having two opposed edges from which the longitudinal sides extend at respective junctions therebetween, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion presenting a convex face extending towards the first face and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar board disposed adjacent thereto, the female portion having a face incorporating a concave portion for receiving the convex face of the male portion, whereby interaction between the convex face and concave portion serves to draw the male portion of one board into the female portion of another board upon relative angular movement between the two boards towards a position whereby they are in side-by-side relation, said relative angular movement being about a fulcrum defined by engagement between one junction of one board and the adjacent junction of the other board, and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the body, the first and second interlocking elements of adjacent boards being adapted to interlock when the two boards are in side-by-side relation

22. A board comprising an elongate body having first and second opposed faces and two longitudinal sides, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a section presenting a convex face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar board disposed adjacent thereto, the female portion having a face incorporating a concave section for receiving the convex face of the male portion, whereby interaction between the convex face and concave section serves to draw the male portion of one board into the female portion of another board upon relative angular movement between the two boards towards a position whereby they are in side-by-side relation and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, wherein wherein the section presenting the convex face comprises a plurality of segments disposed one adjacent another.

23. A board according to claim 22 wherein the segments are disposed angularly to define facets and edges between adjacent facets.

24. A member comprising an elongate body having first and second opposed faces and two longitudinal sides, the first face having two opposed edges from which the longitudinal sides extend at respective junctions therebetween, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion comprising a lobe section presenting a cam face extending towards the first face and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar member disposed adjacent thereto, the female portion having a face incorporating a receiving portion for receiving the lobe section of the male portion, whereby interaction between the cam face and the receiving portion serves to draw the male portion of one member into the female portion of another member upon relative angular movement between the two members towards a position whereby they are in side-by-side relation, said relative angular movement being about a fulcrum defined by engagement between one junction of one member and the adjacent junction of the other member, and wherein the first locking portion further comprises a first interlocking element disposed between the male portion and the second face of the body, and the second locking portion further comprises a second interlocking element disposed between the female portion and the second face of the body, the first and second interlocking elements of adjacent boards being adapted to interlock when the two members are in side-by-side relation.

25. A member comprising an elongate body having first and second opposed faces and two longitudinal sides, a first locking portion provided at one longitudinal side and second locking portion provided at the other longitudinal side, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a lobe section presenting a cam face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion of a similar member disposed adjacent thereto, the female portion having a face incorporating a receiving section for receiving the cam face of the male portion, whereby interaction between the cam face and receiving section serves to draw the male portion of one member into the female portion of another member upon relative angular movement between the two members towards a position whereby they are in side-by-side relation, and wherein the cam face comprises a plurality of segments disposed one adjacent another.

26. A coupling for interlocking two members each having first and second opposed faces, the coupling comprising a first locking portion provided on one member and a second locking portion provided on the other member, wherein the first locking portion comprises a male portion configured as a tongue, the male portion having a lobe section presenting a cam face, and the second locking portion comprises a female portion configured as a groove for receiving the male portion, the female portion having a face incorporating a receiving section for receiving the cam face of the male portion, whereby interaction between the cam face and receiving section serves to draw the male portion into the female portion upon relative angular movement between the two members towards an interlocked position, and wherein the cam face comprises a plurality of segments disposed angularly one adjacent another.

27. A coupling substantially as herein described with reference to the accompanying drawings.

28. A member substantially as herein described with reference to the accompanying drawings.

29. A board substantially as herein described with reference to the accompanying drawings.