PRIORITY

This application claims priority to and the benefit of Australian Patent Application No. 2018901695, filed May 16, 2018, and Australian Patent Application No. 2019203393, filed May 14, 2019, the entire contents of each of which are incorporated herein by reference.

The present invention provides improvements relating to trusses, including roof trusses.

In a house, there can be a variation in the lateral position of the top chord of a roof truss relative to an underlying support structure (typically a frame) -generally a wall structure - to which the truss is tied down or otherwise secured by a fastener, such as a screw. Where the wall includes, in addition to the structure, brickwork beside the structure and thus a cavity, the top chord can overhang the wall structure to a relatively large extent (typically by 600mm or 450mm), so as to define part of an eave in the house, or instead overhang the wall to a relatively small extent (typically by l50mm), such that the exterior surface of a fascia received over the overhanging end of the truss will be substantially flush with the outer face of the brickwork. Where the wall does not include such brickwork, e.g. instead comprising panelling applied to the wall structure (as is common where the wall is an internal one), the top chord will often not overhang the wall structure at all. There is thus, correspondingly, a variation in the distance between the end of the top chord and the position at which it receives the fastener to secure the truss the wall structure. It is desirable that there be an ability to assemble, efficiently and reliably, the truss such that any one of the possible distances is realised.

Regardless of whether there is such variation, it is often desirable that a joint at which the top chord meets the bottom chord of truss (commonly termed a“heel”) be preconfigured with an aperture precisely at the position at which it should receive the fastener, to preclude application of the fastener at an incorrect position or in an incorrect orientation in the truss, and to facilitate the application of the fastener (carried out at height, and thus being relatively hazardous) when the truss has been lifted onto the wall structure. It is desirable to be able to assemble the truss in a manner which is efficient and which reliably results in the aperture being correctly formed and located. According to a first aspect of the present invention, there is provided a member configured to define a sloping top chord member of a truss which is to be secured atop a support structure and in which the top chord member is fixed to an end of a bottom chord member of the truss at a heel, the member being configured with through holes disposed at predetermined positions therealong, to each of which holes corresponds a respective possible lateral position of a lower end of the top chord member relative to said end in the truss, the member being fixable to said end whereby the heel is formed and whichever one of the lateral positions is appropriate is realised, such that the hole to which that lateral position corresponds is located to position correctly a fastener for securing the truss to said structure when received through that hole.

In a preferred embodiment of the invention, a laterally outer one of the holes is disposed so that the lateral position to which that hole corresponds is such that the top chord member does not project beyond the heel. Preferably, the laterally outer hole is disposed so that the lateral position to which that hole corresponds is such that an end face of the top chord member is substantially flush with a laterally outermost extent of the end of the bottom chord member.

In a preferred embodiment of the invention, a laterally inner one of the holes is disposed so that the lateral position to which the hole corresponds is such that the top chord member projects beyond the heel a set distance.

In a preferred embodiment of the invention, a laterally intermediate one of the holes is disposed so that the lateral position to which that hole corresponds is such that the end of the top chord member projects beyond the heel a predetermined distance which is less than said set distance.

Preferably, the member is of timber.

Preferably, the member is configured with markers each of which corresponds to a respective one of said lateral positions and can be aligned with a datum on a member configured to define the lower chord member during manufacture of the truss such that the respective lateral position is realised. Preferably, each marker is alignable with a laterally outer edge of the member configured to define the lower chord member, said edge defining the datum. Pointers or arrows may define respective ones of said markers. According to a second aspect of the present invention, there is provided a method of manufacturing a member according to the first aspect, comprising operating a drilling machine such that spaced cutting tools thereof simultaneously drill through a workpiece from which the member is to derive, thus creating said through holes.

In a preferred embodiment of the invention, the method includes operating a printer of the drilling machine to apply to the workpiece markings defining the markers.

According to a third aspect of the present invention, there is provided the member manufactured by a method according to the second aspect.

According to a fourth aspect of the present invention, there is provided member configured to define a bottom chord member of a truss which is to be secured atop a support structure and in which an end of said member is fixed to a sloping top chord member of the truss at a heel, wherein said end is configured with an opening which passes through upper and lower faces thereof and is arranged so as to align with a through hole in the top chord member when said end is fixed to the top chord member, such that the opening and hole define an aperture through the heel which is located to position correctly a fastener for securing the truss to said structure when received through the aperture.

Preferably, the opening is elongate along a longitudinal axis of the bottom chord member, whereby the formation of the aperture is despite a degree of variability in a lateral position of the top chord member relative to said end during the fixing of the end to the top chord member.

Preferably, the opening is defined by a slot which opens through said upper and lower faces and extends along said axis.

Preferably, the opening passes laterally outwardly through the end.

Preferably, the member of the fourth aspect is configured with a chamfer which defines said upper face of the end and is arranged to abut an underside of the top chord member when said end is fixed to the top chord member whereby a pitch of the top chord in the truss is defined. Preferably, the member of the fourth aspect is of timber.

According to a fifth aspect of the present invention, there is provided a set of members, comprising members each according to either or each of the first and third aspects.

Preferably, the set further comprises at least one additional member, the or each additional member being configured to define said bottom chord member. Preferably, the or each additional member is configured to define the member of the fourth aspect.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a truss which is to be secured atop a support structure, and which includes a bottom chord member and a sloping top chord member fixed to an end of the bottom chord member at a heel, the method comprising:

arranging a member configured to define the top chord member and a member configured to define the bottom chord member to establish whichever one of plural possible lateral positions of a lower end of the top chord member relative to said end in the truss is appropriate, the member configured to define the top chord member being configured with through holes disposed at predetermined positions therealong, to each of which holes a respective one of said possible lateral positions corresponds; and

fixing together the so arranged members to form the heel, such that the hole to which the appropriate lateral position corresponds is located to position correctly a fastener for securing the truss to the support structure when received through that hole.

The fastener may be held in said hole to which the appropriate lateral position corresponds during the fixing together of the members, for subsequent receipt by the support structure, or instead inserted into the hole after the fixing together of the members, for receipt by the support structure.

Preferably, the member configured to define the bottom chord member is configured with a chamfer on an upper side thereof, and the arranging of the members is such that an underside of the member configured to define the top chord member abuts the chamfer whereby a pitch of the top chord member in the truss is defined. In a preferred embodiment of the invention, a laterally outer one of the holes is disposed so that the lateral position corresponding to that hole is such that the top chord member does not project beyond the heel. Preferably, the laterally outer hole is disposed so that the lateral position to which that hole corresponds is such that an end face of the top chord member is substantially flush with a laterally outermost extent of the end of the bottom chord member.

In a preferred embodiment of the invention, a laterally inner one of the holes is disposed so that the lateral position to which the hole corresponds is such that the top chord member projects beyond the heel a set distance.

In a preferred embodiment of the invention, a laterally intermediate one of the holes is disposed so that the lateral position to which that hole corresponds is such that the end of the top chord member projects beyond the heel a predetermined distance which is less than said set distance.

Preferably, the member configured to define the top chord member is sourced from a stock of such members, through holes being disposed in each of those members at said predetermined spaced positions.

Preferably, the member configured to define the top chord member is configured with markers each of which corresponds to a respective one of said lateral positions, and the arranging of the members comprises alignment of the marker corresponding to the appropriate lateral position and a datum on the member configured to define the lower chord member, such that the appropriate lateral position is realised. Preferably, alignment of the marker corresponding to the appropriate lateral position and the datum comprises alignment of that marker with a laterally outer edge of the member configured to define the lower chord member, said edge defining the datum. The markers may be defined by respective pointers or arrows.

Preferably, the members are timber. Preferably, the fixing together of the members comprises applying at least one nail plate to the members.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a truss which is to be secured atop a support structure, and which includes a bottom chord member and a sloping top chord member fixed to an end of the bottom chord member at a heel, the method comprising arranging a member configured to define the top chord member and a member configured to define the bottom chord member such that a through hole in the member configured to define the top chord member and an opening which passes through upper and lower faces of an end of the member configured to define the bottom chord member align, and fixing together the so arranged members to form the heel, whereby the aligned hole and opening define through the heel an aperture which is located to position correctly a fastener for securing the heel to the support structure when received through the aperture.

The fastener may be held in said hole during the fixing together of the members, for subsequent receipt through the opening and by the support structure, or instead inserted into the hole after the fixing together of the members, for receipt through the opening and by the support structure.

Preferably, the opening is elongate along a longitudinal axis of the bottom chord member, whereby the formation of the passage is despite a degree of variability in a lateral position of the top chord member relative to said end during the fixing of the end to the top chord member.

Preferably, the opening is defined by a slot which opens through said upper and lower faces and extends along said axis.

Preferably, the opening passes laterally outwardly through the end.

Preferably, the member configured to define the bottom chord member is configured with a chamfer which defines said upper face of the end and is arranged to abut an underside of the top chord member when said end is fixed to the top chord member whereby a pitch of the top chord in the truss is defined.

Preferably, the members are of timber.

In a preferred embodiment of the invention, said aperture is defined by said opening and said hole to which the appropriate lateral position corresponds.

According to an eighth aspect of the present invention, there is provided the truss manufactured by a method according to either or each of the sixth and seventh aspects. According to a ninth aspect of the present invention, there is provided building method in which a truss manufactured by a method according to either or each of the sixth and seventh aspects is secured atop the support structure, the method comprising securing the truss to the support structure with a said fastener received through said aperture or said hole to which the appropriate lateral position corresponds.

According to a tenth aspect of the present invention, there is provided a building formed via a method according to the ninth aspect.

The invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic side view of a truss top chord member, configured with preformed through holes and locating markers, in accordance with a preferred embodiment of the invention;

Figure 2 is a schematic view showing the relative positions of the top chord member and a bottom chord member in the truss in where the top chord member does not project beyond an end of the bottom chord member;

Figure 3 is a schematic view showing the relative positions of the top and bottom chord members in the truss where the top chord member projects beyond the bottom chord member end to an extent;

Figure 4 is a schematic view showing the relative positions of the top and bottom chord members in the truss where the top chord member projects beyond the bottom chord member end to a greater extent;

Figure 5 is a perspective view of the end of the bottom chord, showing a slot formed therein to facilitate the preconfiguring of a heel of the truss with an aperture correctly located to receive a fastener to secure the truss to an underlying wall structure; and

Figure 6 is a perspective view illustrating alignment of the slot and a respective one of the through holes to define the aperture in each of the arrangements shown in Figures 2 to 4;

Figure 7 is a perspective view illustrating an exemplary alternative configuration of the bottom chord member end and alignment of one of the through holes with the slot in that end; and Figure 8A shows details an assembly comprising the truss, a member forming part of a support structure underlying the truss, and a fastener securing the truss to that member to tie the truss down; and

Figure 8B shows details an assembly comprising the truss, a member forming part of an alternative support structure underlying the truss, and a fastener securing the truss to that member to tie the truss down.

Shown in Figure 1 is a timber member 1 configured to define or form part of a top chord in a roof truss 10 the configuration of which may vary as shown in Figures 2 to 4, the truss 10 including a timber member 3, defining or forming part of a bottom chord thereof, to a laterally outer end of which member the member 1 is secured.

Referring to Figures 8A and 8B, the top chord member 1 and bottom member 3 are secured together by nail plates 2 applied to opposite faces of the truss 10, whereby the truss 10 is configured with a joint or "heel" 4 comprising the thus interconnected members 1, 3. The truss 10 is to be supported atop a support structure which is to form part of a building, and secured to a member 30 of that structure, by means of a screw 20, in order to define part of a roof in the building. In the assembly shown in Figure 8A, the member 30 is defined by a lintel or beam 31, e.g. a beam at the perimeter of an alfresco area or garage in the building, the support structure of which it forms a part being part of a wall structure or other structure in the building. In the assembly shown in Figure 8B, the member 30 is a top plate 33 of a wall frame defining the support structure and forming part of an internal or external wall of the building.

The support structure can vary without departure from the invention. For example, it may, alternatively, comprise another truss, e.g. a floor truss, of the building. Also possible are embodiments of the invention in which the truss and underlying support structure form part of a structure which is other than a building.

Referring to Figure 5, the laterally outer end of the bottom chord member 3 is configured with a chamfer 5, the inclination of which dictates the pitch of the top chord member 1 in the truss 10, whereby the bottom chord end is configured with a tip 6 defining a laterally outer edge 6A of the member 3. Formed through the tip 6 is a slot 7 which opens upwardly through a top face of the member 3 (defined by chamfer 5), downwardly through the bottom face 8 of the member 3, and laterally outwardly through edge 6 A, and which extends along or parallel to the longitudinal axis of the member 3. The slot 7 may be formed, for example, by means of a spindle moulder or saw.

The top chord member 1 is configured with spaced apart preformed holes comprising a laterally outer hole 9A, a laterally intermediate hole 9B, and a laterally inner hole 9C, centres of which he on axes positioned at distances A, B and C, respectively, the bottom chord member longitudinal axis (which will typically be horizontal when the truss 10 is in situ), from a bottom edge 11 of the lower/laterally outer end of the top chord member 1, each of which distances corresponds to a respective one of alternative predetermined lateral positions of the laterally outer end of member 1 relative to the end of the member 3, as described in further detail below. In the present embodiment, the distances A, B and C are 35mm, l85mm, and 635mm respectively.

The top chord member 1 is further configured with markers 13 A, 13B and 13C which are arranged on a side face of the member 1 at/adjacent the edge between that side face and the bottom face of the member 1. The markers 13A, 13B and 13C point to positions from which the central axes of holes 9A, 9B and 9C, respectively, are spaced by distance A, being the intended distance, along bottom chord member axis, from the“heel point” (i.e. the location at which the edge 6A and underside of the top chord member 1 coincide in the truss 10) of the central axis of screw 20. The markers 13A, 13B and 13C are defined by ink applied to the side face.

As will be known to a person skilled in the art, there exist machines configured to drill simultaneously a plurality of holes in a workpiece and apply ink to the workpiece to create markers each of which corresponds to a respective one of the holes. The member 1 is manufactured by using such a machine to drill the holes 9A, 9B and 9C simultaneously into a length of timber defining the workpiece, and apply such ink to it to form the markers 13 A, 13B and 13C. The member 1 is thus, advantageously, formed rapidly and accurately.

The markers 13 A, 13B and 13C could, without departure from the invention, be otherwise defined, e.g. by indicia other than the arrows illustrated and/or by stickers applied to the side face or formations in or on that side face.

Figure 2 illustrates the variant of truss 10 in which the top chord member 1 is arranged so as to terminate at the heel 4, whereby it does not project beyond the end of bottom chord member 3, the edge 11 thus being positioned at the“heel point” (the position where the edge 6A meets the top chord member 1). During assembly of the truss 10 as shown in Figure 2, the alignment of the members 1 and 3, whereby that edge is so positioned, is facilitated by marker 13 A; more particularly, arranging the members 1 and 3 such that the bottom face of member 1 and chamfer 5 abut and the marker 13 A substantially coincides with, i.e. aligns with and is adjacent to, the edge 6A establishes the correct lateral position of member 1 relative to member 3 and, in turn, locates hole 9A for receipt of the fastener 20 thereby. The thus located hole 9A and the slot 7 align so as to define an aperture through the heel 4 which receives the fastener 20. It will be appreciated that the edge 11 can of itself define a marker corresponding to marker 13 A, whereby the latter can be omitted without departure from the invention.

Figure 3 illustrates the variant of truss 10 in which the top chord member 1 is arranged so as to extend from the heel 4, thereby projecting beyond the end of bottom chord member 3, to an extent, the edge 11 thus being positioned laterally outward of the heel point. During assembly of the truss 10 as shown in Figure 3, the alignment of the members 1 and 3, whereby that edge is so positioned, is facilitated by marker 13B; more particularly, arranging the members 1 and 3 such that the bottom face of member 1 and chamfer 5 abut and the marker 13B substantially coincides with the edge 6A establishes the correct lateral position of member 1 relative to member 3 and, in turn, locates hole 9B for receipt of the fastener 20 thereby. In this case, the thus located hole 9B and slot 7 align so as to define the aperture through the heel 4 which receives the fastener 20.

Figure 4 illustrates the variant of truss 10 in which the top chord member 1 is arranged so as to extend from the heel 4, thereby projecting beyond the end of bottom chord member 3, to a greater extent, the edge 11 thus being positioned further laterally outward of the heel point. During assembly of the truss 10 as shown in Figure 4, the alignment of the members 1 and 3, whereby that edge is so positioned, is facilitated by marker 13C; more particularly, arranging the members 1 and 3 such that the bottom face of member 1 and chamfer 5 abut and the marker 13C substantially coincides with the edge 6A establishes the correct lateral position of member 1 relative to member 3 and, in turn, locates hole 9C for receipt of the fastener 20 thereby. In this case, the thus located hole 9C and slot 7 align so as to define the aperture through the heel 4 which receives the fastener 20. The width W of the slot 7 will typically be slightly larger than the diameter of hole 9A/9B/9C, to accommodate any slight transverse misalignment of the members 1 and 3, ensuring that the aperture will be defined. The length L of the slot 7 is sufficient that, if the designated hole 9A, 9B or 9C is slightly laterally inward of the precise location shown in Figures 2, 3 and 4 respectively, the aperture will nevertheless be defined Also, given that the slot 7 opens through the laterally outer end of the bottom chord member 3, the aperture will likewise be formed if the hole is slightly laterally outward of the respective precise position shown. The slot thus, advantageously, confers a tolerance in the process of assembly the truss 10. The provision of slot 7 eliminates the need to drive the fastener 20 through the end of the member 3, which can cause that end to split, its propensity to do so being exacerbated by the reduced thickness of the timber section at that end due to the chamfer 5.

The markers 13A, 13B and 13C, advantageously, facilitate correct positioning of the members 1, 3 during assembly of the truss. More particularly, arranging the member 1 such that the lower face thereof abuts the chamfer 5 and a marker 13 A, 13B or 13C -whichever is appropriate according to which of the configurations shown in Figures 2, 3 and 4 the truss 10 is to assume - aligns with edge 6A:

• establishes the appropriate lateral position of the lower/laterally outer end of the top chord member 1 relative to the end of the bottom chord member 3;

• locates the central axis of the said corresponding hole 9A, 9B or 9C at the distance A from the heel point, such that the fastener 20, to be received by that hole, will be at the correct position (that position being one which is sufficiently inset from the laterally outer side of the member 31/33); and

• results in alignment of the said corresponding hole 9A, 9B or 9C and the slot 7 such that they form the aperture, correctly positioned and configured.

The truss manufacture is efficient, accurate and repeatable. Provided for is a simplified inventory, comprising standard parts, for systematic manufacture of trusses having any one of the alternative configurations. Owing to the correct formation and location of the aperture being assured, fixing of the truss to the underlying support structure, by application of the fastener 20, can be effected rapidly and easily, so that a tradesperson working at height to apply the fastener 20 is not subjected to unnecessary hazards and can be relatively unskilled. The attendant improvements to safety are achieved in combination with improvements to, rather than at the expense of, manufacturing efficiency and accuracy. In other embodiments of the invention, the tie-down fasteners 20 are to be received in the top chord member 1 at a position remote from the heel, in which case the provision of a slot 7, to align with the appropriate preformed hole in the top chord member 1, is unnecessary. While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

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

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.