AU2002302199A1 - Truss - Google Patents

Description

"TRUSS"

Technical field

This invention relates to a truss. This invention relates particularly to a roof truss.

The invention has particular application to a roof truss for use in, and a method of, forming an attic or the like in a roofing space.

The invention has particular application to a prefabricated roof truss.

It will be appreciated that the expression "roof truss" is not to be construed as being limited to a roof truss which is supported on a wall frame in a conventional sense, but includes trusses which effectively constitute the building frame per se in the sense that the building is igloo-like in cross section. In such an embodiment the truss of the present invention provides support for the building floor, walls, ceiling and roof and is adapted to be supported on the building foundations, footings etc.

Background of Invention

Prefabricated trusses are well known and it is known for attics to be formed when constructing a roof by on-site construction of roofing members in a manner which also provides walling supports for the attic.

Summary of Invention

The present invention aims to provide an alternative to known trusses for use in, and to an alternative to known methods of, framing an attic or the like in a roofing space or framing a building having a room space or the like beneath a roof.

This invention in one aspect resides broadly in a truss for a roof having an attic space or the like, the truss including:- a substantially vertical web adapted to constitute a stud for supporting the attic wall; a substantially horizontal web adapted to constitute a support for the attic ceiling or ceiling battens, and a bottom chord adapted to constitute a bearer or joist for the attic floor. In another aspect this invention resides broadly in a truss for a building having a room space or the like beneath a roof, the truss including:- a substantially vertical web adapted to constitute a stud for supporting the room wall; a substantially horizontal web adapted to constitute a support for the room ceiling or ceiling battens; a bottom chord adapted to constitute a bearer or joist for the room floor, and a top chord adapted to constitute a support for roofing battens. In another aspect this invention resides broadly in a method of framing a roof having an attic space or the like, the method including:- prefabricating a plurality of trusses having a substantially vertical web adapted to constitute a stud for supporting the attic wall, a substantially horizontal web adapted to constitute a support for the attic ceiling or ceiling battens, and a bottom chord adapted to constitute a bearer or joist for the attic floor.

In another aspect this invention resides broadly in a method of framing a building having a room space or the like beneath a roof, the method including:- prefabri eating a plurality of trusses having a substantially vertical web adapted to constitute a stud for supporting the attic wall, a substantially horizontal web adapted to constitute a support for the attic ceiling or ceiling battens, a bottom chord adapted to constitute a bearer or joist for the attic floor and a top chord adapted to constitute a support for roofing battens.

It is preferred that the truss includes a pair of opposed vertical webs. It is also preferred that the bottom chord is a parallel chord truss-joist.

It is also preferred that the truss is substantially prefabricated.

The truss can be made from any suitable material such as timber, or as in one preferred embodiment, the truss members are metal.

In this embodiment it is preferred that the truss members are made from reversibly nestable substantially Z shaped chord members and substantially tubular bracing members, the tubular bracing members being crimped or substantially flattened at their ends. It is also preferred that the reversibly nestable substantially Z shaped chord members have in section a web having a linear portion and a divergent portion which extends to one side of the linear portion, a minor flange extending from the linear portion to the one side of the web, and a major flange extending from the divergent portion back to the other side of the web; wherein if one chord is inverted relative to another with the longitudinal axes of the chords inclined and intersecting with respect to each other, the chords nest such that the respective webs abut and such that the respective minor flanges abut the respective major flanges.

Description of Drawings

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein:- FIG 1 is a perspective view of a roof truss in accordance with the present invention;

FIG 2 is an exploded perspective view of the connection of the vertical web members to the parallel chord truss-joist constituting the bottom chord of the roof truss, as seen in circled element A of FIG 1 ; FIG 3 is an exploded perspective view of the connection of the parallel chord truss-joist constituting the bottom chord of the roof truss to the top chord of the roof truss, as seen in circled element B of FIG 1 ;

»^• FIG 4 is a perspective view of the connection of tubular truss members to the upper parallel chord of the truss joist, and FIG 5 is a plan view of the connection illustrated in FIG 4.

Description of Preferred Embodiment of Invention

As can be seen in FIG 1 , roof truss 10 which is suitable for forming roofing having an attic space or the like has a bottom chord in the form of a parallel chord truss joist 11 , to which are attached top chords 12,13. A horizontal web 14 spans between top chords 12,13 and two vertical webs 15,16 join top chords 12,13 respectively to truss joist 11. Webs 14,15 and 16 thus define a space under the roof line suitable for an attic or the like. When a number of trusses 10 are erected to form a roofing frame, the plurality of webs 14, 15 and 16 in the respective trusses will thus constitute the framing for the attic with webs 14 constituting the support for the attic ceiling or ceiling battens, and webs 15,16 constituting the studs for supporting the attic wall. The bottom chords in the form of truss joists 11 constitute the bearers or joists for the attic floor.

Truss joist 11 has top and bottom parallel chords 17 and 18, end supports 20, 21 and internal triangulation bracing webs 19. Web 14 supports a trio of triangulation bracing webs 24 and triangulation bracing webs 22, 23 respectively link top chords 12, 13 to top chord 17 of truss joist 11.

The chords and triangulation bracing webs illustrated are made from metal. Chords 12, 13, 17, and 18, end supports 20 and 21 , and webs 14, 15 and 16 are substantially Z shaped members which are nestable when reversed as described and illustrated in our International Patent application PCT/AU98/00316, the contents of which are incorporated herein by reference. Triangulation bracing webs 19, 22, 23 and 24 are tubular members of substantially oval or elliptical cross-section.

The reversibly nestable substantially Z shaped chord members illustrated here and described in more detail in the international application referred to above have in section a web having a linear portion and a divergent portion which extends to one side of the linear portion, a minor flange extending from the linear portion to the one side of the web, and a major flange extending from the divergent portion back to the other side of the web; wherein if one chord is inverted relative to another with the longitudinal axes of the chords inclined and intersecting with respect to each other, the chords nest such that the respective webs abut and such that the respective minor flanges abut the respective major flanges.

The interconnection of the vertical webs 15,16 to truss joist 11 (circled element A) is seen in exploded detail in FIG 2 which is substantially self explanatory. Triangulation bracing webs 19,23 are crushed or flattened at their end to facilitate connection to chord 17 by a single nut and bolt. It will be seen that chord 17 has cutouts 27 and 28 to accommodate web 16 and angled brace 23 respectively, and that web 16 has cutouts 29 and 30 to accommodate chords 17 and 18 respectively.

The interconnection of top chords 12,13 to truss joist 11 (circled element B) is seen in exploded detail in FIG 3 which is substantially self explanatory. Triangulation bracing web 19 is crushed or flattened at its end to facilitate connection to chord 17 by a single nut and bolt. It will be seen that chord 17 has cutout 31 to accommodate angled top chord 12, and that end support 21 has cutout 32 to accommodate top chord 17. The heel of end support 21 is supported on the lower web of Z shaped lower chord 18. As also seen in FIG 3, roof truss 10 is fastened to the wall structure by means of tie 44 which is slid in slot 45 in wall frame top plate 25 when the lower chord 18 rests on the top plate. Tie 44 is fastened to truss 10 when connecting end support 18 and lower chord 18 by a single nut and bolt, and is fastened to wall stud 26 by self tapping screws as shown. The triangulation bracing webs 19 of truss joist 11 are crushed or flattened at their ends to facilitate connection to parallel chords 17 and 18 by single nuts and bolts.

The arrangements described above are such that the various truss members are interconnected such that together their width is substantially that of the width of the substantially Z shaped chord members.

It will thus be appreciated that the roof truss of the present invention is for for a roof having an attic space or the like, and includes a substantially vertical web 15 or 16 (as illustrated there are two vertical webs, although it will be clear that only one could be utilised) adapted to constitute a stud for supporting the attic wall. The truss also has a substantially horizontal web 14 adapted to constitute a support for the attic ceiling or ceiling battens, and a bottom chord 11 adapted to constitute a bearer or joist for the attic floor. As illustrated the bottom chord is a parallel chord truss joist.

Turning now to FIGS 4 and 5, these drawings illustrate in greater detail the method of connection of tubular triangulation bracing webs to a substantially Z shaped chord member.

A connection 33 is illustrated between an open substantially Z shaped structural member 34 and two tubular truss members 35 with a single bolt 42. Tubular truss members 35 have a closed substantially oval/elliptical cross-section formed by substantially straight sidewalls 36 and curved end walls 37. The tubular truss members 35 have an end 38 which is crimped, crushed or flattened such that flat sidewalls 36 are compressed to decrease the space therebetween. FIG 5, which is a top view of FIG 4, also shows the crimped nature of the ends 38.

Also as shown in FIGS 4 and 5, crimped end 38 has two side portions

39 and 40, which in a preferred embodiment form an angle with a center portion 41 . The angle at which the side portions 39 and 40 bend with respect to the center portion facilitates the securing of multiple truss members with a single bolt 42.

The center portion 41 is relatively planar and is secured to the planar portion of another structural member by a single bolt. Center portion 41 has sidewalls 36 which in a preferred embodiment are closer together than the sidewalls 36 in the side portions 39 and 40. The angle at which the side portions 39 and 40 may bend with respect to the center portion facilitates the securing of multiple truss members 35 with a single bolt 42.

Another feature of the connection of the tubular truss members 35 to the open structural member 34 includes the substantially planar portion 43 of open structural member 34 abutting the substantially planar surface of the tubular truss member 35.

Although FIGS 4 and 5 include two tubular truss members 35, the number of members which may be attached is not limited to two and may be one or several. Further, the connection system invention is also not limited to the use of a bolt and other suitable connectors well known in the art may be used. Also, although the structural members are shown connected to open structural member 34 which has a minor flange, major flange and divergent portion, this connection system is not limited to a structural member of the type illustrated. Rather, tubular truss members 35 may be connected to any structural member known in the art having a substantially planar surface.

It will of course be realised that whilst the above has been given by way of an illustrative example of this invention, all such and other modifications and variations hereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

Claims (10)

The claims defining the invention are as follows:-

1. A truss for a roof having an attic space or the like, the truss including:- a substantially vertical web adapted to constitute a stud for supporting the attic wall; a substantially horizontal web adapted to constitute a support for the attic ceiling or ceiling battens, and a bottom chord adapted to constitute a bearer or joist for the attic floor.

2. A truss as claimed in claim 1 , wherein the truss includes a pair of opposed vertical webs.

3. A truss as claimed in claim 2, wherein the bottom chord is a parallel chord truss-joist.

4. A truss as claimed in claim 3, wherein the roof truss is substantially prefabricated.

5. A truss as claimed in claim 4, wherein the roof truss members are metal.

6. A truss as claimed in claim 1 , wherein the roof truss members are made from reversably nestable substantially Z shaped chord members and substantially tubular bracing members, the tubular bracing members being crimped or substantially flattened at their ends.

7. A truss as claimed in claim 6, wherein the reversibly nestable substantially Z shaped chord members have in section a web having a linear portion and a divergent portion which extends to one side of the linear portion, a minor flange extending from the linear portion to the one side of the web, and a major flange extending from the divergent portion back to the other side of the web; wherein if one chord is inverted relative to another with the longitudinal axes of the chords inclined and intersecting with respect to each other, the chords nest such that the respective webs abut and such that the respective minor flanges abut the respective major flanges.

8. A truss for a building having a room space or the like beneath a roof, the truss including:- a substantially vertical web adapted to constitute a stud for supporting the room wall; a substantially horizontal web adapted to constitute a support for the room ceiling or ceiling battens; a bottom chord adapted to constitute a bearer or joist for the room floor, and a top chord adapted to constitute a support for roofing battens.

9. A method of framing a roof having an attic space or the like, the method including:- prefabricating a plurality of trusses having a substantially vertical web adapted to constitute a stud for supporting the attic wall, a substantially horizontal web adapted to constitute a support for the attic ceiling or ceiling battens, and a bottom chord adapted to constitute a bearer or joist for the attic floor.

10. A method of framing a building having a room space or the like beneath a roof, the method including:- prefabricating a plurality of trusses having a substantially vertical web adapted to constitute a stud for supporting the attic wall, a substantially horizontal web adapted to constitute a support for the attic ceiling or ceiling battens, a bottom chord adapted to constitute a bearer or joist for the attic floor and a top chord adapted to constitute a support for roofing battens.