NZ713944A - Quick-connect fastening for use in building construction - Google Patents

Abstract

A fastening for coupling two components of a building structure comprises a first part for attachment to one of the components and a second part for attachment to the other of the component, the two parts each being of plate-like form. The first part provides a multiplicity of locking projections and the second part provides a multiplicity of apertures arranged in a configuration equivalent to that of the locking projections of the first part such that when the two parts are applied together in face-to-face relation the locking projections of the first part can extend through the apertures of the second part and lock to the second part to thereby lock the two parts together against separation of the two parts. The fastening has particular utility as quick-action fastening for locking a roof truss to the top plate of an underlying wall frame.

Description

QUICK-CONNECT FASTENING FOR USE IN BUILDING CONSTRUCTION The present invention relates to a quick-connect fastening for use in building construction and more particularly, but not exclusively, in the construction of roofs.

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 it is still not a straightforward process as it has to be done by people working at the height of the roof and, moreover, safety issues can arise prior to components being installed and properly braced, more so if required "safe work" procedures are not followed and which can happen in practice.

In the installation of the trusses they need to be anchored to the underlying wall structure of the building, typically by fastening the bottom chord of a truss to the top plate of an underlying wall frame and which itself is usually of prefabricated form. A typical attachment consists of brackets fastened by nails to the top plate and bottom chord, itself quite a time consuming exercise carried out at roof level.

The present invention provides an attachment system which provides quicker fastening between the truss and top plate or other underlying structure during installation, and additionally has utility in coupling other components in the roof structure and other building structures.

H:\a zh\I nterwoven\N RPortbl\D CC\A ZH\ 8751140_1. docx-2/11/2015 According to the present invention there is provided a fastening for coupling two components of a building structure, comprising a first part for attachment to one of the components and a second part for attachment to the other of the component, the two parts each being of plate-like form, the first part providing a multiplicity of locking projections and the second part providing a multiplicity of apertures arranged in a configuration equivalent to that of the locking projections of the first part such that when the two parts are applied together in face-to-face relation the locking projections of the first part can extend through the apertures of the second part and lock to the second part to thereby lock the two parts together against separation of the two parts.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows in exploded form components of a truss assembly; Figure 2 shows the truss assembly in its assembled configuration with supplementary trusses hingedly attached to a main truss and the supplementary trusses in a folded configuration against the main truss; Figure 3 shows schematically a typical roof structure as could be formed from the truss assemblies; Figure 4 is a side view showing respective parts of a quick-action fastening in accordance with a preferred embodiment of the invention, the parts being shown prior to coupling of the two parts; Figure 5 is a perspective view equivalent to Figure 4; Figure 6 is a side view similar to Figure 4 but showing the two parts in their coupled relation; and Figure 7 is a perspective view corresponding to Figure 6.

Although the present invention is a quick-action fastening for use in building construction, an important, but not exclusive, use of the fastening is in the installation of roofing trusses, and the preferred embodiment will be described within that context by way of example.

H:\a zh\I nterwoven\N RPortbl\D CC\A ZH\8751140_1. docx-2/11/2015 With initial reference to Figures 1 to 3, prefabricated trusses which, in the assembled roof structure are to be attached to and extend transversely from another prefabricated truss, usually one of the larger trusses and which will be referred to for simplicity as a "main" truss, are assembled to the main truss by hinges as part of the pre- fabrication process. The hinges provide a secure connection between the main truss and the other trusses, referred to for simplicity as "supplementary trusses", and permit the supplementary trusses to be swung from a position in which a face of the supplementary truss lies adjacent a face of the main truss 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 is in position on the top plate or other underlying structure, the supplementary trusses can then be swung outwardly from the face of the main truss into its required orientation transversely to the main truss. Depending on the design of the roof structure, that orientation can be at 90º to the main truss or at an acute angle.

Figure 1 shows by way of example a main truss 2 and a set of three supplementary trusses 4 prior to assembly together by hinges as discussed above. In the assembled roof, the supplementary trusses are intended to form a hip end of the roof.

Figure 2 shows the supplementary trusses 4 attached to the main truss 2 by the hinges and folded to lie with their faces against the adjacent face of the main truss for transportation to site and for lifting into position. In the particular design shown, each supplementary truss 4 is hinged to the top chord and bottom chord of the main truss 2 at hinge points 6, the hinge axis of each supplementary truss 4 being vertical considered in relation to the main truss when lying in a vertical plane in its installed condition.

As briefly discussed at the outset, following erection into position, 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 present invention in its preferred embodiment relates to a quick-connect two-part fastening pre- installed to the truss and top plate during the pre-fabrication of the truss and wall frame and which does not require working with a nail gun at height to make the connection.

H:\a zh\I nterwoven\N RPortbl\D CC\A ZH\ 8751140_1. docx-2/11/2015 While the fastening is being described within the context of fastening a truss to a wall plate, the fastening has applicability in other situations where a strong, permanent, mechanical connection is required between components. For example it could be used to provide a connection between a main truss and further supplementary trusses (so -called jack trusses, for example) in the type of structure previously discussed, after erection and stabilisation of the main truss by the hinged supplementary trusses.

With reference to Figures 4 to 7 the quick-connect fastening of the preferred embodiment comprises male and female parts 10, 12 each of plate-like form, and each preferably being pressed out of metal sheet. The female part 12 is shaped to form a series of parallel crests 14 of arcuate form extending across the width of the plate, with valleys 16 in the form of flat lands between adjacent crests. Each crest is apertured along its length with a row of parallel slots 18 which are clearly shown in Figure 5. The male part 10 is profiled in a manner generally corresponding to that of the female part except that each of the crests is defined by a row of generally parallel ribs 20 each of a width and peripheral configuration which enables the rib 20 to fit within one of the slots 18 when the face of one of the two parts is applied against the face of the other part. Flat lands 21 are formed between each row of ribs 20. The spacing between adjacent ribs 20 in each row of ribs corresponds to that between adjacent slots 18 in each row of slots, and the rows of ribs and slots are at the same spacing. A locking lug or tang 22 projects outwardly from the opposite edges of each rib 20, with the two tangs of each rib being in a divergent configuration. The configuration is such that when a rib 20 is pressed into a corresponding slot 18 in the female part, its two tangs 22 will deflect resiliently inwardly to enable the rib to enter the slot and when the two tangs have passed through the slot the two tangs will move outwardly under their inherent resilience to their original divergent configuration to engage behind the outer surface of the female plate in the zone of the slots in order to provide a positive locking engagement (s ee Figure 6).

Although in the embodiment described, a locking tang extends from each of two opposite sides of each rib and which is the preferred arrangement, in principle locking could be achieved by just a single tang on each rib. In a further alternative, resiliently H:\a zh\I nterwoven\N RPortbl\D CC\A ZH\8751140_1. docx-2/11/2015 deflectable locking tangs could be formed on one or both sides of each slot with the tangs then being deflected by passage of the ribs through the slots on engagement of the two parts and then returning to their original configuration to positively lock the ribs within the slots against withdrawal.

In a further alternative, the tangs could be formed in an appropriate configuration on the female part or even on both parts.

In the example given of an attachment of the bottom chord of a truss to the top plate of a wall frame, one of the two parts, the female part for example, is fixed to the top plate with its slotted crests facing upwardly and the other part, in this case therefore the male part, is fixed to the underside of the bottom chord of the truss with its locking ribs facing downwardly. Fixing can occur by any suitable means such as screwing, nailing or gluing, or by nail-plates. Nailing or other fixing can occur through holes (the holes are not shown) formed in the flat lands 16, 21 of both plates and which will be in direct contact with the top plate and bottom chord. It will be understood that if the truss with its male plate 10 is pushed down onto the female plate 12 on the top plate to engage the locking ribs 20 within the slots 18, a positive locked connection between the two can be achieved very quickly. The connection is very strong and is not capable of release by application of reversed forces. In a typical situation where the wall frames and trusses and other components are prefabricated in a factory situation, the two parts of each fastening are installed during pre-fabrication to facilitate easy and accurate location of the truss relative to the wall frame during erection with coupling of the truss to the top plate being achieved very quickly by engagement of its coupling part with the corresponding coupling part already fixed to the top plate.

It will be understood that in this situation if the truss is perfectly aligned with the top plate, all of the locking ribs in the male part will engage and lock with the corresponding slots in the female part. Although in principle perfect alignment could arise (or could be achieved by manoeuvring the truss during installation) given that both parts of the fastening are installed in a factory situation which would permit high accuracy in H:\a zh\I nterwoven\N RPortbl\D CC\A ZH\8751140_1. docx-2/11/2015 placement, in practice this may not be possible in the erected structure for a variety of reasons, for example some inaccuracy in the laying of a concrete slab or other footings, inaccuracy in setting of the wall frames and so forth. The design of the two-part fastening provides a multiplicity of fixing points in a fixing matrix formed by parallel rows of locking ribs and slots. The sizing of the two parts in conjunction with the number of fixing points formed within the matrix can be determined so that even with a maximum expected degree of longitudinal and/or lateral misalignment between the two fastening parts likely to arise when the truss is lowered onto the top plate, a sufficient number of locking ribs will engage within the slots to provide the required secure connection between the truss and top plate. In typical Australian building conditions, the misalignment is likely to be no more than 20mm whereby the two plates of the fastening can be designed to account for the eventuality.

Although the quick-connect fastening of the preferred embodiment has been described within the context of its application to the installation of roof trusses and indeed provides particular benefit in that situation due to potential safety issues which can arise in truss installation for the reasons earlier discussed, nevertheless it must be understood that the fastening has much broader applications to a variety of coupling situations in building construction.

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Claims (5)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A fastening for coupling two components of a building structure, comprising a first part for attachment to one of the components and a second part for attachment to the other of the component, the two parts each being of plate-like form, the first part providing a multiplicity of locking projections and the second part providing a multiplicity of apertures arranged in a configuration equivalent to that of the locking projections of the first part such that when the two parts are applied together in face-to-face relation the locking projections of the first part can extend through the apertures of the second part and lock to the second part to thereby lock the two parts together against separation of the two parts.

2. A fastening according to claim 1, wherein each locking projection of the first part includes a locking tang capable of resilient inwards deflection to enable the projection with tang to move through the aperture upon engagement of the two parts, with the tang then deflecting outwardly when it has moved through the aperture to engage against the opposite face of the second part adjacent the aperture.

3. A fastening according to claim 1, wherein at least one edge of each aperture of the second part includes a locking tang capable of resilient outwards deflection to enable the locking projection to move through the aperture upon engagement of the two parts, with the tang then deflecting inwardly to lock the projection against withdrawal from the aperture.

4. A fastening according to any one of claims 1 to 3, wherein the second part is shaped to form a series of parallel crests of arcuate form with each crest being formed with a series of parallel slots spaced along its length, the slots constituting said apertures, and the first part is shaped to form a series of parallel crests, each crest being defined by a series of spaced parallel ribs, each of the ribs being of a size to fit within one of the slots of the second part whereby each rib constitutes a said locking projection.

5. A fastening according to any one of claims 1 to 4, wherein one of the parts is H:\a zh\I nterwoven\N RPortbl\D CC\A ZH\8751140_1. docx-2/