WO2018191116A1

WO2018191116A1 - Method of constructing a truss assembly and supplementary truss for use in a truss assembly for building construction

Info

Publication number: WO2018191116A1
Application number: PCT/US2018/026465
Authority: WO
Inventors: Bernard Joseph Kennelly
Original assignee: Illinois Tool Works Inc.
Priority date: 2017-04-13
Filing date: 2018-04-06
Publication date: 2018-10-18
Also published as: AU2018202473A1

Abstract

A method of constructing a supplementary truss for use in a truss assembly for building construction, the truss assembly having a main truss and one or more supplementary trusses that are hingedly connected to the main truss for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss lies adjacent the face of the main truss and an erected configuration in which the supplementary truss extends transversely to said face, the method comprising the steps of: positioning on a jig table self securing hinges to define the substantially vertical swinging axis of the supplementary truss, the jig table having a plurality of fixtures for positioning the hinges and chord members of the truss in predetermined alignment; positioning fasteners on the jig table at predetermined locations for fixing the chord members together; and applying the chord members and a web extending between the chord members to the jig table for engagement with the hinges and the fasteners to form the supplementary truss.

Description

METHOD OF CONSTRUCTING A TRUSS ASSEMBLY AND SUPPLEMENTARY TRUSS FOR USE IN A TRUSS ASSEMBLY FOR BUILDING CONSTRUCTION

PRIORITY

This application claims priority to and the benefit of Australian Application No.

2017901382, filed April 13, 2017 the entire contents of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a method of constructing a supplementary truss for use in a truss assembly for building construction and a method of constructing a truss assembly.

BACKGROUND OF THE INVENTION

In some types of building construction it is conventional practice to construct the roof using trusses prefabricated in a factory situation and transported to site for erection onto wall frames or other wall structure of the building. Although the main structure of a roof will normally be formed by a series of trusses arranged in spaced parallel relation, in the construction of a complex roof such as one having hips and/or gables further trusses are installed to a face of one or more of other trusses within the structure after installation so as to extend transversely from the face of that truss, usually at right angles thereto. Typically those further trusses will also be of prefabricated construction whereby substantially the entire basic roof structure can be assembled on site from prefabricated components. Although construction of a roof from prefabricated trusses removes much of the skill which would otherwise be needed to construct a roof and, of course, enables relatively quick construction, nevertheless installing and fastening supplementary trusses within the main structure by installing to the face of a main truss for instance, can add a degree of complexity. The supplementary trusses require separate handling and need to be accurately located relative to the main truss and then attached using suitable brackets. This has to be done by people working at the height of the roof of course, and does involve a degree of skill. The environment in which the installers are working at roof level is not a stable environment and required "safe work practices" are not always adhered to. Many of those working on site can be at risk until a main truss and its supplementary trusses are installed, temporarily braced, and made stable. Additionally, issues sometimes issues arise through absence of adequate documentation for identification and accurate placement of the supplementary trusses.

A solution to these problems has been proposed in Australian patent application no. 2015252101 , also to the present applicant. This solution proposes a first (main) truss and one or more second (supplementary or jack) trusses attached to the first truss to extend transversely to a face of the first truss upon erection of the truss assembly, wherein the or each second truss is hingedly connected to the first truss for swinging movement about a substantially vertical axis between a folded configuration in which the second truss lies adjacent the face of the first truss and an erected configuration in which the second truss extends transversely to said face.

Although this arrangement simplifies construction of a building, reduces construction time and improves the dimensional accuracy of the truss assembly, the inventors have found that the requirements for dimensional accuracy in the manufacture of the supplementary truss, in particular the positioning of the hinges and the straightness of the timber members, are too great and that the accuracy of the truss assembly can suffer due to inaccuracy of the second trusses, both during their construction and their securement to the first truss.

Preferred embodiments of the present invention seek to ameliorate one or more disadvantages of previous truss assemblies.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a method of constructing a supplementary truss for use in a truss assembly for building construction, the truss assembly having a main truss and one or more supplementary trusses that are hingedly connected to the main truss for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss lies adjacent the face of the main truss and an erected configuration in which the supplementary truss extends transversely to said face, the method comprising the steps of:

positioning on a jig table self securing hinges to define the substantially vertical swinging axis of the supplementary truss, the jig table having a plurality of fixtures for positioning the hinges and chord members of the truss in predetermined alignment;

positioning fasteners on the jig table at predetermined locations for fixing the chord members together; and

applying the chord members and a web extending between the chord members to the jig table for engagement with the hinges and the fasteners to form the supplementary truss.

Preferably, the hinges are formed with apertures for receipt of fasteners for securing the supplementary truss to the main truss, the hinges being positioned on the jig table by engagement of the apertures with pins formed on the fixtures.

Preferably, the hinges are formed with nail plate teeth for securement to the chord members as the chord members are applied to the jig table. Preferably, the hinges are configured to bend along a line of weakness formed along the hinge.

Preferably, the fasteners are nail plates.

In some embodiments, the supplementary truss is a jack truss and the main truss is a girder truss.

According to another aspect of the present invention there is provided a method of constructing a supplementary truss for use in a truss assembly for building construction, the truss assembly having a main truss and one or more supplementary trusses that are hingedly connected to the main truss for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss lies adjacent the face of the main truss and an erected configuration in which the supplementary truss extends transversely to said face, the method comprising the steps of:

fixing the chord members and a web extending between the chord members together;

applying the assembled chord members and web to the jig table for engagement with the hinges to form the supplementary truss.

According to another aspect of the present invention there is provided a method of constructing a truss assembly for use in building construction, the truss assembly having a main truss and one or more supplementary trusses that are hingedly connected to the main truss for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss lies adjacent a face of the main truss and an erected configuration in which the supplementary truss extends transversely to said face, the method comprising the steps of:

providing at least one supplementary truss constructed according to a method of the above described type;

aligning a lower chord of the or each supplementary truss with a lower chord of the main truss; and

securing the hinges of the or each supplementary truss to the main truss to form a truss assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 is a perspective view of a truss assembly constructed according to one embodiment of the invention;

Figure 2 is a perspective view of a supplementary truss for use with the truss assembly;

Figures 3 to 8 illustrate different steps in constructing a lower chord of the supplementary truss;

Figures 9 to 13 illustrate different steps in constructing an upper chord of the supplementary truss; and

Figures 14 to 20 illustrate different steps in securing supplementary trusses to a main truss.

DETAILED DESCRIPTION

With reference to Figure 1 , there is shown a truss assembly 10. The truss assembly 10 is configured for use in a building construction.

The truss assembly 10 includes a main truss 12 and two supplementary trusses 14. Although illustrated as having two supplementary trusses 14, it will be appreciated that arrangements having one or more (such as 3, 4 or five for example) supplementary trusses 14 will also fall within the scope of the present invention. The supplementary trusses 14 are hingedly connected to the main truss 10 for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss 14 lies adjacent the face of the main truss 12 and an erected configuration in which the supplementary truss 14 extends transversely to said face.

The supplementary trusses 14 are prefabricated trusses which, in the assembled roof structure, are to be attached to and extend transversely from, the main truss 12, which is another prefabricated truss and is usually larger.

Hinges 16 provide a secure connection between the main truss 12 and the supplementary trusses 14, and permit the supplementary trusses 14 to be swung from a position in which a face of the supplementary truss 14 lies adjacent a face of the main truss 12 for transportation to site on the bed of a truck and lifting into position on site, typically by means of a crane. When the main truss 12 is in position on the top plate or other underlying structure, the supplementary trusses 14 can then be swung outwardly from the face of the main truss 12 into its required orientation transversely to the main truss 12. Depending on the design of the roof structure, that orientation can be at 90° to the main truss 12 or at an acute angle.

The supplementary trusses 14 are attached to the main truss 12 by the hinges 16 and folded to lie with their faces against the adjacent face of the main truss 12 or transportation to site and for lifting into position. In the assembled roof, the supplementary trusses 14 are intended to form a hip end of the roof.

In the particular design shown, each supplementary truss 14 is hinged to the top chord and bottom chord of the main truss 12 via hinges 16. The hinge axis of each supplementary truss 14 is desired to be vertical considered in relation to the main truss 12 when lying in a vertical plane in its installed condition. Although in the embodiment shown the supplementary trusses 14 are hinged to the top and bottom chords of the main truss 12 by respective upper and lower hinges 16, other placements of the hinges would be possible with different designs of main and supplementary trusses. However it is envisaged that in most circumstances there would be at least an upper and lower hinge for each supplementary truss although it is conceivable that a single longer hinge might suffice in some circumstances.

The hinges 16 are formed with teeth, similar to those formed on a nail plate, for securement of the hinge 16 to the chord members. Other suitable means such as screwing, nailing, or gluing, may also be used. The primary function of the hinged connection between the supplementary truss 14 and main truss 12 is to enable the supplementary truss 14 to be swung out from its folded condition assumed during transportation and lifting and, as such, the hinges 16 only need to have capacities to withstand the handling and installation loads. Although in principle they could also be designed to withstand in-service loading in the completed roof structure, in practice it is envisaged supplementary fixings would be subsequently installed to withstand the in-service loading, these supplementary fixings being fitted later in the installation process when the majority of the roof structure is in place and braced to provide a stable and safe working environment.

In the example shown, each of the supplementary trusses 14 is of a length which enables the set of supplementary trusses 14 to be folded flat against the face of the main truss 12 and which is desirable as it enables a series of such truss assemblies 10 to be stacked flat for transportation. Nevertheless the overall concept would still be applicable for use with somewhat longer supplementary trusses in which, in their folded condition for transportation, an outer end of one supplementary truss might overlap the inner end of the adjacent supplementary truss whereby in its folded state it is inclined to the adjacent face of the main truss rather than lying flat against it.

Figure 2 illustrates an assembled supplementary truss 14 secured to a jig table 18. By assembling the supplementary truss 14 on a jig table 18, the hinges 16 can be positioned to accurately define the vertical axis of the supplementary truss 14, thereby ensuring that swinging of the supplementary truss 14 from the main truss 12 results in an end 22a of the truss which is outermost in use being accurately positioned for securement to a building frame. Also, by aligning ends of the bottom chord 20, variations in the bottom chord 20, which may arise due to bowing of the timber member, can be accommodated while ensuring that the ends of the bottom chord 20, which is where the supplementary truss 14 is secured, are more accurately positioned.

The jig table 18 has a plurality of fixtures 24 for positioning the hinges 16 and chord members 20, 26 of the truss in predetermined alignment;

Assembling the supplementary truss 14 commences with positioning the lower chord 20 on the jig table 18. As can be seen in Figure 3, fixtures 24a, 24b, which are preferably integrally formed, are provided to guide an end of the lower chord 20 which is closest to the main truss 12. The fixtures 24 include two pins 28 (although only one can be seen in the illustrated embodiment) that are configured for engagement with holes that are formed in the hinges 16 for securement to the main truss.

As illustrated in Figure 4, fastener 30 is positioned on the jig table 18 at predetermined locations for fixing the lower chord 20 and webs 32a, 32b (Figures 6 and 7) together. In the illustrated example, hinge 16 includes a planar portion 16a and a tab portion 16b, the planar portion 16a being used to secure to hinge 16 to the supplementary truss 14 as well as securing the bottom chord 20 and web 32a to each other. It will be appreciated that a smaller hinge and separate fastener for securing the bottom chord 20 and web 32a together may also be used.

Figure 5 illustrates the bottom chord 20 being installed with a corner of the bottom chord 20 being received in a correspondingly shaped indentation formed in fixture 24a for accurate positioning of the innermost lower corner of the supplementary truss. A further fixture is provided at end 22a to ensure that the lower chord is fully supported on the jig table 18. After the bottom chord 20 has been installed, web 32a is then installed against the bottom chord 20 and fixture 24b, as shown in Figure 6. As illustrated in Figure 7, internal web 32b is then installed against the bottom chord 20 and web 32a. Finally, and as shown in Figure 8, another fastener 30, which is a nail plate in the illustrated embodiment, is applied to an upper surface of the joint to ensure it that the bottom chord 20 and webs 32a, 32b are secured together.

Figures 9 to 13 illustrate the upper chord 34 being installed in the supplementary truss 14 and on the jig table 18. Web 32a is already positioned against fixtures 24c and 24d during installation. Another two pin 28 are provided, which may extend from fixture 24c or 24d, though preferably fixture 24c and 24d are also integrally formed.

Hinge 16 again includes a planar portion 16a and a tab portion 16b, the planar portion 16a being used to secure to hinge 16 to the supplementary truss 14 as well as securing the upper chord 34 and web 32a to each other. It will again be appreciated that a smaller hinge and separate fastener for securing the upper chord 34 and web 32a together may also be used.

The upper chord 34 is applied against fixture 24d and against end 22a and secured in position by hinge 16 through engagement of the teeth of hinge 16 biting into the upper chord 34. A further end fixture (not shown) may be provided at end 22a for accurate positioning of the upper chord 34.

Finally, another fastener 30 , which is a nail plate in the illustrated embodiment, is applied to an upper surface of the joint to ensure it that the upper chord 34 and web 32a are secured together, thereby completing construction of the supplementary truss 14, as shown in Figure 13.

Although the above process describes construction of the supplementary truss 14 as occurring on the jib table 18, the chord members 20,34 web 32 may be assembled remote from the jib table 18 and positioned on the jig table 18 for securement of the hinges 16 thereto.

Figures 14 to 20 illustrate the process of securing a constructed supplementary truss 14 to a previously constructed main truss 12, manufactured using previously known processes.

Initially, the location 36 at which the hinges 16 are required to be secured is determined and marked on the main truss 12. The supplementary truss 14 is then positioned on the main truss 12 at the marked location while ensuring that ends 22a, 22b of the supplementary truss 14 are in alignment with a bottom chord of the main truss 12, as illustrated in Figure 16.

As illustrated in Figure 17, a screw 40 is inserted through both the main truss 12 and the supplementary truss 14 to facilitate securing the supplementary truss 14 to the main truss 12 and to prevent the supplementary truss swinging out from the main truss 12 until desired to do so.

Each hinge 16 is then secured to the main truss 12, each via three screws that are received in the upper chord 34 and the lower chord 20, as can be seen in Figure 18 to 20, though it will be appreciated that other fasteners may also be used. The process is then repeated for each supplementary truss 14 that is to be secured to the main truss 12.

As the hinged assembly of the supplementary trusses to the main truss takes place as part of the pre-fabrication process in the factory, the supplementary trusses will be accurately positioned relative to the main truss. All that is required is for the supplementary truss to be swung about the vertical hinge axis into its required orientation transverse to the main truss and fastened at its outer end to underlying wall structure, usually the top plate of the underlying wall frame. The example which has been given is of a hip formed with two supplementary trusses hinged to the main truss. It will readily be understood that there may be more than or less than two supplementary trusses in such a structure and the general principles described herein are applicable to a wide range of other roof structures such as gables or valleys defined by trusses in mutually transverse orientations.

Following erection into position roof trusses are usually fixed to the underlying top plate or other structure by brackets nailed to the top plate and lower chord of the truss, typically using a nail gun for this purpose.

The embodiments have been described by way of example only and modifications are possible within the scope of the invention disclosed.

Claims

1 . A method of constructing a supplementary truss for use in a truss assembly for building construction, the truss assembly having a main truss and one or more supplementary trusses that are hingedly connected to the main truss for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss lies adjacent the face of the main truss and an erected configuration in which the supplementary truss extends transversely to said face, the method comprising the steps of:

2. A method according to claim 1 , wherein the hinges are formed with apertures for receipt of fasteners for securing the supplementary truss to the main truss, the hinges being positioned on the jig table by engagement of the apertures with pins formed on the fixtures.

3. A method according to claim 1 or claim 2, wherein the hinges are formed with nail plate teeth for securement to the chord members as the chord members are applied to the jig table.

4. A method according to any preceding claim, wherein the hinges are configured to bend along a line of weakness formed along the hinge.

5. A method according to any preceding claim, wherein the fasteners are nail plates.

6. A method according to any preceding claim, wherein the supplementary truss is a jack truss and the main truss is a girder truss.

7. A method of constructing a supplementary truss for use in a truss assembly for building construction, the truss assembly having a main truss and one or more supplementary trusses that are hingedly connected to the main truss for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss lies adjacent the face of the main truss and an erected configuration in which the supplementary truss extends transversely to said face, the method comprising the steps of:

8. A method of constructing a truss assembly for use in building construction, the truss assembly having a main truss and one or more supplementary trusses that are hingedly connected to the main truss for swinging movement about a substantially vertical axis between a folded configuration in which the supplementary truss lies adjacent a face of the main truss and an erected configuration in which the supplementary truss extends transversely to said face, the method comprising the steps of:

providing at least one supplementary truss constructed according to any preceding claim;

9. A supplementary truss or truss assembly manufactured in accordance with a method according to any preceding claim.