AU2014268220A1

AU2014268220A1 - A Building Truss

Info

Publication number: AU2014268220A1
Application number: AU2014268220A
Authority: AU
Inventors: Jeff Milligan
Original assignee: Milligan Maxine
Current assignee: Milligan Maxine
Priority date: 2004-07-02
Filing date: 2014-11-27
Publication date: 2016-06-16
Anticipated expiration: 2024-07-02
Also published as: AU2014268220B2

Abstract

The invention relates to a truss comprising: first and second chord 5 members that are tee-shaped in cross-section with the crosspieces of tees outermost in the truss, wherein each of the chord member comprises a pair of angle sections with adjacent legs of the sections forming the leg of the tee; a plurality of spaced apart first cross members, an end of each of the first cross members being pivotally fixed to the first chord member and the other end of 10 each of the first cross members being pivotally fixed to the second chord member; and, a plurality of spaced apart second cross members, one each of which is interposed between a pair of the first cross members, an end of each of the second cross members being pivotally fixed to the first chord member at the point of fixation of a the first cross member, and the other end of each of 15 the second cross members being fixable to the second chord member at the point of fixation of the other of the pair of first cross members, wherein the chord members are integrally formed of a folded material. Fig. 1 Fig. 2

Description

This invention relates to a truss for use in building construction. In particular, the invention relates to a truss which can be folded into a more compact form for storage or transportation. The invention also relates to buildings comprising trusses according to the invention.

Building trusses comprise a pair of spaced apart elongated members called chords held together by cross members called struts or webs. The cross members are disposed with respect to the chord members so as to form a plurality of triangles thereby providing a rigid structure.

Fabricating trusses on a building site is not always desirable or possible, so trusses are frequently prefabricated off-site and delivered to the site as required. However, this can present transportation and storage difficulties because of the dimensions of assembled trusses.

Folding or collapsible trusses are known. However, many of these trusses are for specific applications and are not suitable as general building trusses. A collapsible truss which does qualify as a general building truss is described in U.S. Patent No. 4,546,591. A disadvantage of this truss is, however, that when in the assembled condition the ends of the chord members are not aligned. This complicates utilisation of the truss in constructing a building. Furthermore, two different sets of struts are required in the U.S. 4,546,591 truss.

Any reference to publications cited in this specification is not an admission that the disclosures constitute common general knowledge in Australia.

Certain embodiments of the present invention provide a truss which may be folded into a compact configuration and which may overcome the disadvantages of known folding or collapsible trusses.

According to a first aspect of the invention, there is provided a truss comprising: first and second chord members that are tee-shaped in crosssection with the crosspieces of tees outermost in said truss, wherein each said chord member comprises a pair of angle sections with adjacent legs of said sections forming the leg of said tee; a plurality of spaced apart first cross members, an end of each of said first cross members being pivotably fixed to said first chord member and the other end of each of said first cross members being pivotably fixed to said second chord member; and a plurality of spaced apart second cross members, each of which is interposed between a pair of said first cross members, an end of each of said second cross members being pivotably fixed to said first chord member at the point of fixation of a said first cross member, and the other end of each of said second cross members being fixable to said second chord member at the point of fixation of the other of said pair of first cross members, wherein said first and second cross members are on alternate sides of the leg of the tees of said chord members; wherein, when said second cross members are fixed to said second chord member, said first and second chord members are held rigidly spaced apart with the ends thereof substantially aligned; and wherein each said chord member is integrally formed of a folded material.

It will be appreciated from the foregoing paragraph that when released from the second chord member of the truss, the second cross members may be folded towards the first chord member. The entire truss may then be collapsed with the first and second chord members folded against each other. A much more compact unit may then be provided which aids storage and transportation of the truss.

The chord members may be formed of folded sheet metal. The sheet metal may comprise galvanised steel.

The chord members may include a foot portion from which first and second leg portions upwardly extend, and arm portions that extend outwardly from upper ends of the leg portions.

The leg portions may be parallel to each other and may abut each other.

The arm portions may be parallel to each other. The arm portions may be formed in a common plane.

Flange portions may extend downwardly from distal ends of the arm portions. The flange portions may be parallel to each other. The flange portions may be parallel to the leg portions.

The chord members may be formed from folded C-purlins.

The chord members may be formed of the folded material using substantially 90 degree folds.

The cross members may have any cross-sectional shape.

In the assembled truss, the cross members in conjunction with chord members may form a plurality of triangles with the apexes of triangles alternating from side to side along the truss.

In a preferred embodiment, the first and second cross members may be of the same length.

Assembled trusses may be joined by connecting pieces fitted into the ends of the chord members of abutted trusses. Connecting pieces may be merely a plate which fits into the space between the pairs of angle sections of abutted chord members and thereby spanning the junction between the connected trusses.

Pivotal fixing of the ends of cross members to the chord members may typically be with a nut and bolt. It will be appreciated by one of skill in the art that the fixing may be at the leg of the tee of a chord member.

It will be appreciated that holes may be provided in chord and cross members for fixing cross members to chord members.

Ends of cross members may advantageously be rounded to facilitate rotation of a cross member about a pivot point.

In a second aspect, the invention provides a frame member for a building, said frame member comprising a plurality of trusses according to the first embodiment of the invention. A frame member according to the second embodiment at a minimum may comprise an inverted "U" shaped structure - two trusses which may stand upright in use bridged by a third truss which may act as a roof support. Angle or elbow elements and base members may be provided to form the frame members and to mount the frame member to a surface.

It will be appreciated however that more than one truss may be used in each upright portion of a frame. Similarly, more than one truss may be used to bridge between upright portions of a frame and this is particularly the case if a building with a peaked roof is desired. In this case, the bridging portion of a frame may comprise at least two trusses which meet centrally of the 35 frame and may be joined by an angle or cap element.

Reduction elements may also be provided to connect a truss of a particular assembled width to another truss of a lesser width.

Trusses according to the invention, and the angle, elbow and cap elements may advantageously be provided predrilled to facilitate the fixing of cladding, roofing, guttering, battens, braces and the like to frame members. Base members may similarly be provided predrilled to facilitate fixing the members to a surface. A further aspect of the present invention provides buildings comprising trusses and frame members according to the first and second aspects.

An advantage of the trusses of the invention is that trusses can be fabricated from a few components. In the preferred format, only one type of angle section is required to fabricate trusses of a particular load bearing maximum. Because of the modular nature of frame elements, variously sized buildings can be fabricated from a small number of elements and in many instances only a single truss size.

Because trusses of the invention may be folded, prefabrication of components for frame elements of a building may be carried out off-site. The folded trusses occupy minimal space during transportation.

Truss elements and other frame element components may typically be fabricated from a metal or metal alloy. A preferred material is steel. Typically, the steel may be rust-proofed by hot-dip galvanising or by coating with suitable primers.

Yet a further aspect of the present invention provides a method of construction of a frame member according to the second aspect.

So that the invention may be better understood, a truss and other elements will be exemplified with reference to the accompanying drawings which are briefly described below:

Figure 1 is an elevational view of portion of a truss in an assembled state.

Figure 2 is an elevational view of the same truss portion shown in Figure I but in a collapsed state.

Figure 3 is an end view at plane A-A of Figure 1.

Figure 4 is an end view at plane B-B of Figure 2.

Figure 5 is an elevational view of an angle element.

Figure 6 is an end view at plane C-C of Figure 5.

Figure 7 is an elevational view of a base member.

Figure 8 is an end view at plane D-D of Figure 7.

Figure 9 is an elevational view of a reduction element.

Figure 10 is an elevational view of an apex connection.

Figure 11 is an end view of a portion of a truss in an assembled state, according to an alternative embodiment of the present invention.

Figure 12 is an end view of the same truss portion shown in Figure 11 but in a collapsed state.

Figure 13 is an end view of a chord member of the truss of Figure 11.

Figure 14 is an end view of a C-purlin from which the chord member of Figure 13 can be formed.

The same item number is used for a feature present in different drawings. The drawings are not all to the same scale.

With reference to Figure 1, there is shown assembled truss 1 comprising first and second chord members 2 and 3, first cross members 4a to 4c and second cross members 5a and 5b. The first and second cross members continue along the length of the truss as shown in the portion comprising item 1. It can be seen that ends of cross members 5a and 4b, and 5b and 4c, are fixed at the same point on chord member 2 while it is the ends of cross members 4b and 5b that are fixed at the same point on second chord member 3. In this way the cross members form triangles along the truss.

Figure 2 shows truss portion 1 in a collapsed state. To achieve collapse (or folding) of the truss, ends 4d, 4e and 4f of cross members 4a to 4c, respectively, of Figure 1 are released from their pivotal connections to chord member 2. Movement of chord member 2 relative to chord member 3 thus allows collapse of the truss as shown in Figure 2.

Figures 3 and 4 are respective end views of the trusses as shown in Figures 1 and 2. In Figure 3, chord members 2 and 3 can be seen and cross members 4c and 5b. It can be also appreciated that chord member 2 consists of angle sections 2a and 2b which are held apart by a spacer 6. Spacer 6 is conveniently a piece of material the same thickness as the legs of angle sections 2a and 2b which is in the form of a plate or disc. Spacer 6 is at the point where ends of cross members 4c and 5b are fixed to chord member 2 (see Figure 1) and bolt 7 with a nut thereon used for this fixing passes through spacer 6. Chord member 3, it will be appreciated from Figure 3, is constructed in the same way as chord member 2.

Turning to Figure 4, which is an end view of collapsed truss 1, chord members 2 and 3 can be seen, the former comprising angle sections 2a and 2b plus spacer 6. Cross member 5b can be seen as well as an end 4g of cross member 4c. It can be appreciated from Figure 4 that only one end of the 4 series cross members is fixed to a chord member in the collapsed state.

An angle element 8 for connecting trusses comprising uprights and roof beams of a building frame is shown in Figures 5 and 6. Angle element 8 comprises a plate of material 9 having edge plates, one of which is indicated at 10. Trusses according to Figures 1 and 3 are fitted at ends 11 and 12 of angle element 8 (see Figure 5) where the components can be bolted or riveted to each other using preformed holes, one of which is indicated at 13. Items 14 and 15 of the angle element are stiffeners (see Figure 5).

Figures 7 and 8 show a base member 16 which comprises a plate 17 having side plates 18 and 19. Two angle sections 20 and 21 form the bottom of the base member. As with the angle element of Figures 5 and 6, holes are provided in base member 16 for fixing a truss thereto. One such hole is item 22.

The reduction element 23 of Figure 9 comprises a plate 24, with side plates 25 to 28 and stiffeners 29 to 31. Ends of trusses are fixed at ends 32 and 33 of the reduction element.

The apex connection element 34 of Figure 10 similarly comprises a plate 35, side plates 36 to 39 and a stiffener 40. Trusses forming roof beams of a building frame are fixed to ends 41 and 42 of apex connection 34.

The trusses shown in Figures 1 to 4 can be manufactured from any size angle iron which can be pre-coated before assembly. Trusses can vary in length or size to suit any design application. The other exemplified components are similarly fabricated from pre-coated steel sized as appropriate for the design requirements.

Figure 11 illustrates an end view of an assembled truss T, according to an alternative embodiment of the present invention. Figure 12 illustrates an end view of the truss T in a collapsed state.

The truss T comprises first and second chord members 2’ and 3’ and a plurality of first and second cross members 4a-4c, 5a-5c extending between the first and second chord members 2’ and 3’, similar to the truss 1 of Figure 1. The first and second cross members 4a-4c, 5a-5c continue along the length of the truss 1 ’ as described with reference to the truss 1, and the truss 1 ’ can be collapsed in a similar manner to the truss 1 of Figure 1.

The chord member 2’ is integrally formed and include angle sections 2a’ and 2b’. As described in further detail below, the chord member 2’ can be formed of pressed sheet metal, either directly, or by folding a C-purlin.

Figure 13 illustrates an end view of the chord member 2’. The chord members 2’ includes a foot portion 50 from which first and second leg portions 52a, 52b upwardly extend. The leg portions 52a, 52b are parallel and abut each other. Flowever, the skilled addressee will readily appreciate that the leg portions 52a, 52b may be in a spaced arrangement relative to each other, for example using a spacer similar to the spacer 6 of the purlin 1.

The chord member 2’ then extends outwardly from upper ends of the leg portions 52a, 52b to form arm portions 54a, 54b. The arm portions 54a, 54b are parallel to each other and are formed in a common plane. The leg portions 52a, 52b and the arm portions 54a, 54b together form a tee shape.

Finally, flange portions 56a, 56b extend downwardly from distal ends of the arm portions 54a, 54b. The flange portions 56a, 56b are parallel to each other, and parallel to the leg portions. As such, all bends of the chord member 2’ are substantially 90 degree bends.

The chord member 3’ is advantageously identical to the chord member 2’.

The cross members 4a-4c, 5a-5c are fixed to chord members 2’, 3’ by a bolts 7 with nuts thereon. Each bolt passes through an aperture of a cross member 4a-4c, 5a-5c and apertures of the leg portions 52a, 52b. This skilled addressee will, however, appreciate that other means may be employed for attaching the cross members 4a-4c, 5a-5c to the chord members 2’, 3’.

It can be appreciated from Figure 12 that only one end of the 4 series cross members is fixed to a chord member in the collapsed state.

Figure 14 is an end view of a C-purlin 60 from which a chord member 2’, 3’ can be formed. The C-purlin includes a base portion 62, arm portions 64a, 64b, and flange portions 66a, 66b at distal ends of the arm portions 64a, 64b. The C-purlin 60 is folded along a longitudinal fold line 68 that extends along the entire length of the C-purlin 60 to form a 180 degree bend, as illustrated by fold arrows 70.

The skilled addressee will, however, appreciate that the chord members 2’, 3’ can be formed from sheet metal directly.

It will be appreciated that many changes can be made to the trusses and components exemplified above without departing from the broad ambit and scope of the invention. One such change is the use a T section rather than the paired angle irons as chord members.

Terms such as "comprise", "comprised" or "comprising" are used herein to denote the inclusion of a stated integer but do not necessarily exclude the inclusion of other integers.

Claims

CLAIMS:

1. A truss comprising: first and second chord members that are tee-shaped in cross-section with the crosspieces of tees outermost in said truss, wherein each said chord member comprises a pair of angle sections with adjacent legs of said sections forming the leg of said tee; a plurality of spaced apart first cross members, an end of each of said first cross members being pivotally fixed to said first chord member and the other end of each of said first cross members being pivotally fixed to said second chord member; and a plurality of spaced apart second cross members, each of which is interposed between a pair of said first cross members, an end of each of said second cross members being pivotally fixed to said first chord member at the point of fixation of a said first cross member, and the other end of each of said second cross members being fixable to said second chord member at the point of fixation of the other of said pair of first cross members, wherein said first and second cross members are on alternate sides of the leg of the tees of said chord members; wherein, when said second cross members are fixed to said second chord member, said first and second chord members are held rigidly spaced apart with the ends thereof substantially aligned; and wherein each said chord member is integrally formed of a folded material.
2. The truss of claim 1, wherein the chord members are formed of folded sheet metal.
3. The truss of claim 2, wherein the sheet metal comprises galvanised steel.
4. The truss of any one of the preceding claims, wherein the chord members include a foot portion from which first and second leg portions upwardly extend, and arm portions that extends outwardly from upper ends of the leg portions.
5. The truss of claim 4, wherein the leg portions are parallel and abut each other.
6. The truss of claim 4, wherein the arm portions are parallel to each other.
7. The truss of claim 4, wherein the arm portions are formed in a common plane. Finally, flange portions 56a, 56b extend downwardly from distal ends of the arm portions 54a, 54b. The flange portions 56a, 56b are parallel to each other, and parallel to the leg portions.
8. The truss of claim 4, further comprising flange portions extend downwardly from distal ends of the arm portions.
9. The truss of claim 8, wherein the flange portions are parallel to each other
10. The truss of claim 8, wherein the flange portions are parallel to the leg portions.
11. The truss of any one of the preceding claims, wherein the chord members are formed from folded C-purlins.
12. The truss of any one of the preceding claims, wherein the chord members are formed of the folded material using substantially 90 degree folds.
13. The truss of any one of the preceding claims, wherein said first and second cross members are of the same length.
14. The truss of any one of the preceding claims, wherein the ends of said cross members are rounded.
15. A frame member for a building, said frame member comprising a plurality of trusses according to any one of claims 1 to 14.
16. The frame member of claim 15, wherein said trusses are joined by angle, apex or reduction elements.
17. A building comprising a plurality of trusses according to any one of claims 1 to 14 and/or frame members according to claim 15 or claim 16.
18. A method of construction of a frame member according to claim 15, said method comprising: i) joining two of said trusses standing upright to at least one further truss bridging said upright trusses with angle elements; ii) mounting the resultant structure to a surface with base members to form said frame member.
19. The method of construction of claim 18, wherein pairs of said upright trusses are bridged by two bridging trusses that are connected by an apex element.