This invention relates to a building frame member such as a roof truss or hip rafter.

Roof trusses generally comprise a bottom chord and at least one (and more commonly two or more) obliquely arranged top chord. A web defined by a plurality of web members extends between the bottom chord and the top chord. When the truss is installed in a building, some of the web members are subjected to compressive forces which can cause the web members to bend or flex out of the plane of the truss. The bending or flexing weakens the truss and can lead to total failure of the truss.

U.S. Patent No. 6,148,579 (Rolf ) teaches a wood truss including web members with braces attached thereto. In one embodiment, the braces have side walls with integrally formed teeth for imbedding into front and/or back sides of the web members. In another embodiment, the braces are generally planar with extending sides walls and are embedded into the lateral sides of the web members.

U.S. Patent No. 5,946,879 (Pellock ) teaches a truss including web members with braces attached thereto. The braces have flanges with integrally formed teeth embedded into front or back sides of the web members.

In order to prevent the web members from bending or flexing, web members are reinforced in a number of different ways. One method is to tie the web members together. Other methods use a reinforcing member, such as a brace. However, conventional methods of reinforcing the truss make truss manufacture more difficult, particularly when the truss is formed in a semi-automated fashion. For example, some reinforcing members have integral, punched teeth for attaching to web members. The teeth are pressed into web members by a floating press, i.e., a clamp suspended from an overhead carriage for movement between several splice pedestals supporting the web members and chords in assembled position. Unfortunately, it takes substantial time for an operator to attach the reinforcing members. The teeth require multiple, repetitive press cycles by the floating press at each of several positions along the reinforcing member. Further, it can be difficult or impossible for operators to reach the press into positions at the interior of the truss. An additional difficulty is that a portion of each reinforcing member typically extends beyond the confines of the truss. Because the reinforcing member is attached to a side of the web member which faces out of the plane of the truss, it extends to a thickness greater than a thickness of the truss. Consequently, the reinforcing member interferes with stacking or nesting of assembled web members and completed trusses during handling and transportation. Further, the reinforcing member is subject to being crushed.

Among the objects of the present invention is the provision of a building frame member which is suitably reinforced with minimum disruption to the normal manufacturing process, particularly if a floating press-type system is used to form the frame member; the provision of a brace secured to a web member by a separate fastener such that the web member can be manufactured in the normal fashion and the brace simply connected in a separate operation which does not interfere with the construction of the frame member; and the provision of a brace which is entirely within the confines of the truss.

Thus, according to one aspect of the present invention, there is provided a structural truss comprising a plurality of structural members arranged in a configuration defining a plane; a web including at least one web member extending between two structural members within said plane for being subjected to compression forces when the truss is in use, the web member having a front side and an opposite back side which face opposite directions substantially out of said plane, and having lateral sides located between the front and back sides which face opposite directions substantially within said plane, said truss being characterised by a brace having a base and at least one side wall projecting outwardly from the base in a direction away from said at least one web member, the brace being secured to the web member for reinforcing the web member, the brace engaging the web member at one of said lateral sides ; and at least one fastener securing the brace to the web member, the fastener penetrating the web member at one of said lateral sides; wherein said front and back sides of the web member remain free from fasteners.

Other objects and features will be in part apparent and in part pointed out hereinafter.

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

• Figure 1 is a perspective view of a brace used in the preferred embodiment of the invention;
• Figure 2 is a cross-sectional view through the brace of Figure 1;
• Figure 3 is a view of a truss according to one embodiment of the invention; and
• Figures 4 to 8 are cross-sectional views of embodiments of the invention showing various different brace configurations.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

With reference to Figures 1 and 2, a reinforcing member, or brace 10, according to the present invention is shown. The brace 10 includes a base 12 and a pair of side walls 14 and 16 which extend from the base 12 and are separated by the base 12. The walls 14 and 16 are generally parallel and extend in the same direction at right angles with respect to the base 12. The walls 14 and 16 have in-turned flanges 18 at their free ends.

The base 12 is provided with a plurality of holes 20 along its length. In the embodiments shown, three such holes are provided but a different number of holes could be used if desired.

The brace 10 typically has a length of 1.5 meter to 3 meters. If desired, sets of braces in stock lengths could be provided so that a suitable length can be selected for connection to a web member depending on the length.

Figure 3 shows one embodiment of the frame member in the form of a building truss which has structural members arranged in a plane. The truss includes a bottom chord 30, two oblique upper chords 32, and a web comprising web members 33 and 35 extending between the chords. The configuration of the truss is standard and, as is well known, the exact location of the web members will vary depending on the configuration and intended use of the truss. The web members 33 generally form tension web members which will be subjected to tensile forces when the truss is in use. The web members 35 will generally form compression web members which will be subjected to compression forces when the truss is in use. To prevent the compression web members 35 from bending or flexing out of the plane of the truss, braces 10 according to Figures 1 and 2 are connected to the web members 35. In the embodiment shown, the web members 35 are formed from wood and have a generally rectangular cross section.

Figure 4 is a cross-sectional view through one of the web members 35 of Figure 3 showing the brace 10 secured to the web member. The web member 35 has first side portions including a front side 35a and a back side 35b which face opposite directions substantially out of the plane of the truss. Second side portions include lateral sides 35c and 35d which face opposite directions substantially within the plane of the truss. The section view of the web member shown in Fig. 4 is oriented with lateral sides 35c and 35d positioned as the bottom and top surfaces, respectively. The brace 10 is secured in place by screws or nails 40 which are hammered or screwed through the holes 20 and which penetrate the web member 35, as shown in Figure 4.

Significantly, the screws or nails 40 are distinct and non-integral with the brace 10. Therefore, the web member and brace may be attached prior to a truss manufacturing process. During that process, there is no need for an operator to reach a floating press to an interior position of the truss, nor any need for repetitive press cycles such as when embedding punched teeth in web members. Thus, the truss manufacturing process is more efficient.

Although the brace 10 is attached to the side 35c of the web member 35, it could be connected to a different side of web member 35. Connecting to sides 35c or 35d locates the brace 10 within the thickness confines of the truss, that is, within a region bounded by parallel planes corresponding to front and back sides 35a and 35b which are spaced apart by the maximum spacing between front and back sides. The brace is positioned entirely between vertical side faces of the chords and web members of the truss when located in position in a building. The brace 10 does not project beyond the vertical side surfaces 35a and 35b of the web member. This arrangement therefore has the advantage that no part of the brace extends beyond the confines of the truss, and the brace will not be crushed nor interfere with stacking of web members or completed trusses. If the brace 10 were connected to sides 35a or 35b or had any portion overlying sides 35a or 35b, a disadvantage is that the brace would project out of the confines of the truss which makes transportation, handling, and stacking of trusses more difficult.

Figure 5 shows an embodiment similarly to Figure 4, but of a configuration in which the brace 10a has a base 12a, a first side wall 14a and a second side wall 16a which extends in a direction opposite the side wall 10a. The wall 14a has in-turned flange 18a, but it will be noted that the wall 16a does not have a flange. The brace 10a is secured to the web 35 by a nail or screw 40 in the same manner as previously described.

In the embodiment of Figure 6, the brace 10b is somewhat similar to the brace 10 of Figure 4, except that the side walls 14b and 16b converge towards one another, and have outwardly turned flanges 18b at their free ends. The brace 10b is secured to the web 35 in the same manner previously described by locating nail or screws 40 through holes in base 12b.

In the embodiments of Figures 4 to 6, the base of the brace is flat.

Although the embodiments of Figures 4 to 6 have been described with reference to web members 35 of a truss of the type shown in Figure 3, the invention is applicable to other frame elements such as hip rafters and braces of the same configuration as those described with reference to Figures 4 to 6 can be secured to a hip rafter in exactly the same manner as described with reference to Figures 4 to 6, so as to reinforce the hip rafter and prevent the hip rafter from bowing in a vertical plane when loaded.

Figure 7 shows a still further embodiment of the invention. In this embodiment the brace 10h includes a base 12h which extends within the confines of the truss. The base 12h has an inwardly directed V-shaped flange 18h at each end. The fastener 40 for securing the brace 10h to the web 35 passes through the base 12h between the flanges 18h.

Figure 8 shows an embodiment similar to that of Fig. 4. Brace 10k has a flat base 12k with side walls 14k and 16k extending from the base. Flanges 18k are provided to give the brace greater strength. The flanges are inwardly turned by about 180 degrees, thereby providing a wider spacing between the flanges than would a smaller turn to permit ready access for inserting screws 40 (Fig. 8). As shown in Fig. 8, the brace 10k remains within the thickness confines of the rectangular web member, and the side walls project outward from the web member 35. The brace engages and is secured to one of the lateral sides 35c or 35d so that the front and back sides 35a and 35b remain free from fasteners. Therefore, the assembled web members and trusses can be firmly stacked, and the reinforcing members and screws or nails will not be crushed.

The embodiments of Figures 4, 6, 7 and 8 have the advantage that the brace 10 is within the confines of the truss to facilitate stacking or nesting of web members and also manufactured trusses.

Furthermore, in some embodiments the brace functions to prevent buckling by increasing the moment of inertia. A portion of the mass of each brace is placed at a distance from the centroid of the web, which increases critical buckling load for a given length web. Embodiments which have: (a) greater mass, or (b) further distance from the web, such as flanges at positions of extremity, provide additional strength benefits relative to embodiments of lesser mass and where the brace is closely adjacent to the web.

The various embodiments provide various relative advantages and may be selected for use according to the particular frame member and/or preference of the operator. Relative dimensions between the side walls, bases, and/or flanges of all embodiments may be selected to achieve desired advantages in moment of inertia and reinforcement while effectively fitting within the dimensions of the particular framework.

In the preferred embodiment of the invention, the fasteners 40 may be any suitable screw, nail, or staple, such as, for example, 14 gauge x 30 mm long type 17 screw.

The embodiment of Figure 7 also offers the advantage of a compact, low profile design which permits stacking/nesting of web members.

Although the rectangular web members of Figures 4 to 8 are preferably formed from wood, the invention is not restricted to such web members and is suitable for any shape and any material web.

Furtherstill, in applications of trusses in which conventional framed hip ends, with their trussed roofs, are used, the hip requires to be 120 mm deep, whereas the rest of the truss top chords are 90 mm deep. This means that they have to rip cut the overhang and make a reduction cut at the support point. This is a time consuming and costly operation. The present invention offers the advantage of providing the alternative of using 90 mm hip rafter and fixing a brace 10 to the bottom edge to effectively reinforce the rafter so that it acts like a 120 mm member. Thus, the web members promote efficiency and lower costs by avoiding additional chord sizes and on-site modifications.

Since modifications within the scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.