US20040172911A1

US20040172911A1 - Building frame member

Info

Publication number: US20040172911A1
Application number: US10/771,056
Authority: US
Inventors: John Tadich
Original assignee: Mitek Holdings Inc
Current assignee: Mitek Holdings Inc
Priority date: 2003-02-04
Filing date: 2004-02-03
Publication date: 2004-09-09
Also published as: EP1445392B1; NZ530932A; AU2004200395A1; DE602004010196D1; EP1445392A2; MY135483A; MY145434A; ZA200400896B; DE602004010196T2; EP1445392A3; AU2004200395B2

Abstract

A reinforcing brace for attachment to a web member of a building framework such as a truss to prevent bending or flexing out of a plane of the truss. Fasteners secure the brace to the web member at a lateral side of the web member such that front and back sides of the web member remain free from fasteners. The brace is entirely within thickness confines of the truss.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 60/444,818, filed Feb. 4, 2003.[0001]

BACKGROUND OF THE INVENTION

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.

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.

SUMMARY OF THE INVENTION

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.

In general, a structural truss according to the present invention comprises a plurality of structural members arranged in a configuration defining a plane. A web including at least one web member extends between two structural members within the plane. The web member has first side portions generally defining a front side and an opposite back side which face opposite directions substantially out of the plane, and has second side portions located between the first portions which generally define opposite lateral sides which face opposite directions substantially within the plane. A brace is secured to the web member for reinforcing the web member, the brace engaging the web member at one of the lateral sides. At least one fastener secures the brace to the web member, the fastener penetrating the web member at one of the lateral sides. The 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.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be described, by way of example, with reference to the accompanying drawings in which: [0008]
FIG. 1 is a perspective view of a brace used in the preferred embodiment of the invention; [0009]
FIG. 2 is a cross-sectional view through the brace of FIG. 1; [0010]
FIG. 3 is a view of a truss according to one embodiment of the invention; and [0011]
FIGS. 4-17 are cross-sectional views of embodiments of the invention showing various different brace configurations.[0012]
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. [0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 and 2, a reinforcing member, or [0014] 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 [0015] 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 [0016] 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.
FIG. 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 [0017] 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 FIGS. 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.
FIG. 4 is a cross-sectional view through one of the [0018] web members 35 of FIG. 3 showing the brace 10 secured to the web member. The web member 35 has first side portions including a front side 35 a and a back side 35 b which face opposite directions substantially out of the plane of the truss. Second side portions include lateral sides 35 c and 35 d 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 35 c and 35 d 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 FIG. 4.
Significantly, the screws or [0019] 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 [0020] brace 10 is attached to the side 35 c of the web member 35, it could be connected to a different side of web member 35. Connecting to sides 35 c or 35 d 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 35 a and 35 b 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 35 a and 35 b 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 35 a or 35 b or had any portion overlying sides 35 a or 35 b, 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.
FIG. 5 shows an embodiment similarly to FIG. 4, but of a configuration in which the [0021] brace 10 a has a base 12 a, a first side wall 14 a and a second side wall 16 a which extends in a direction opposite the side wall 10 a. The wall 14 a has in-turned flange 18 a, but it will be noted that the wall 16 a does not have a flange. The brace 10 a is secured to the web 35 by a nail or screw 40 in the same manner as previously described.
In the embodiment of FIG. 6, the [0022] brace 10 b is somewhat similar to the brace 10 of FIG. 4, except that the side walls 14 b and 16 b converge towards one another, and have outwardly turned flanges 18 b at their free ends. The brace 10 b is secured to the web 35 in the same manner previously described by locating nail or screws 40 through holes in base 12 b.
In the embodiment of FIG. 7, the [0023] brace 10 c is of the same configuration as the brace 10 of FIG. 4, except that the in-turned flanges 18 are not included. In this embodiment the brace is connected to the web 35 so that the web is received between the side walls 14 c and 16 c. Screws or nails 40 passes through holes in base 12 c to secure the brace in place.
In the embodiment of FIG. 8 the [0024] brace 10 d is in the form of a relatively wide wall 16 d, a base 12 d and a relatively short side wall 14 d. The wall 14 d has an in-turned flange 18 d. Holes (not shown) are provided along the length of the longer wall 10 d and screws or nails 40 locate through the holes to secure the wall ad to the web 35. The base 12 d is spaced from the web 35 by the in-turned flange 18 d and the short side wall 14 d.
In the embodiment of FIG. 9 the [0025] brace 10 e has a wide base 12 e which is wider than the width of the web 35, a side wall 14 e, a side wall 16 e, and wherein the side walls 14 e and 16 e are spaced apart by the base 12 e. The side walls 14 e and 16 e are generally parallel and extend in the same direction. In this embodiment the web 35 is received within the brace between the walls 14 e and 16 e and with the base 12 e flush with one of the vertical faces of the web 35. The base 12 e has holes as in the earlier embodiments and the brace 10 e is secured to the web 35 by nails or screws 40 which pass through those holes and penetrate into the web 35. The wall 14 e has an in-turned flange 18 e and the wall 16 e may optionally have an in-turned flange 18 e.
FIGS. 10 and 11 show embodiments of the invention in which the [0026] web 35 is in the form of a metal web formed from tube and having a generally circular cross-section. The thickness confines of the truss for these embodiments is generally within a region bounded by planes defined by outermost lateral position of side portions 35 a and 35 b.
In the embodiment of FIG. 10, the [0027] brace 10 f is of generally the same shape as the brace 10 of FIG. 4. However, in this embodiment the metal web 35 is received within the brace 10 f between the side walls 14 f and 16 f. The brace 10 f is secured to the metal web 35 by a screw 40′ which passes through holes along base 12 f of the brace 10 f and which screw into the web 35. The web 35 may be pre-drilled or the screw 40′ may simply tap the web 35 in order to secure the brace 10 f to the web 35. In this embodiment the walls 14 f and 16 f have in-turned flanges 18 f which have end portions 19 f which are bent more than 90 degrees with respect to the walls 14 f and 16 f so that they are directed towards the web 35.
In the embodiments of FIGS. [0028] 4 to 10, the base of the brace is flat.
In the embodiment of FIG. 11 the [0029] brace 10 g has a base in the form of a curved transition section 12 g which joins with the side walls 14 g and 16 g. The side walls 14 g and 16 g have in-turned flanges 18 g which are the same as those in the embodiment of FIG. 10. Once again, the base 12 g is provided with a plurality of holes which are the same as the holes 20 shown in FIG. 1, through which screw 40′ can locate so as to secure the brace 10 g to the web 35 in the same manner as in the embodiment of FIG. 10.
Although the embodiments of FIGS. [0030] 4 to 11 have been described with reference to web members 35 of a truss of the type shown in FIG. 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 FIGS. 4 to 9 can be secured to a hip rafter in exactly the same manner as described with reference to FIGS. 4 to 9, so as to reinforce the hip rafter and prevent the hip rafter from bowing in a vertical plane when loaded.
FIG. 12 shows a still further embodiment of the invention. In this embodiment the [0031] brace 10 h includes a base 12 h which extends within the confines of the truss. The base 12 h has an inwardly directed V-shaped flange 18 h at each end. The fastener 40 for securing the brace 10 h to the web 35 passes through the base 12 h between the flanges 18 h.
In FIG. 13 the [0032] brace 10 i has a side wall 16 i and a V-shaped flange 18 i at one end. The flange 18 i has an in-turned base wall 12 i which sits generally flush with face 35 c of the web 35. Fastener 40 extends through the wall 16 i to join the brace 10 i to the web 35.
FIG. 14 is similar to FIG. 13, except that both ends of the [0033] wall 16 i are provided with flanges 18 i with in-turned base walls 12 i.
FIGS. 15-17 show an embodiment similar to that of FIG. 4 which has flexibility in that it may be used with either rectangular or circular web members. [0034] Brace 10 k has a flat base 12 k with side walls 14 k and 16 k extending from the base. Flanges 18 k 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. 15) or for receiving web member 35 (FIGS. 16 and 17). As shown in FIG. 15, the brace 10 k remains within the thickness confines of the rectangular web member, and the side walls project outward from the web member 35. FIGS. 16 and 17 show the brace 10 k attached to circular web members of two differing diameters, with the web members received between the side walls. An angled end 19 k provided on each flange 18 k engages the web member. The brace engages and is secured to one of the lateral sides 35 c or 35 d so that the front and back sides 35 a and 35 b 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 FIGS. 4, 6, [0035] 12 and 15 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. [0036]
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. For example, embodiments such as in FIGS. 7-11, [0037] 13, 14, 16 and 17 provide unimpeded access to the base for insertion of the fastener 40. The embodiment of FIG. 7 has a channel shape which requires only two bends in a metallic blank to form the brace. That facilitates a lower manufacturing cost and time relative to more complex configurations. 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 [0038] fasteners 40 may be any suitable screw, nail, or staple, such as, for example, 14 gauge×30 mm long type 17 screw.
The embodiments of FIGS. 12, 13 and [0039] 14 also offer the advantage of compact, low profile designs which permit stacking/nesting of web members.
Although the rectangular web members of FIGS. [0040] 4 to 9 and 12 to 15 are preferably formed from wood, and the circular web members of FIGS. 10, 11, 16 and 17 are preferably formed from metal, the invention is not restricted to these combinations 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 [0041] 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 spirit and 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. [0042]
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. [0043]

Claims

What is claimed is:

1. 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, the web member having first side portions generally defining a front side and an opposite back side which face opposite directions substantially out of said plane, and having second side portions located between the first portions which generally define opposite lateral sides which face opposite directions substantially within said plane;

a brace 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.

2. A structural truss as set forth in claim 1 wherein said web member has a cross-sectional shape which is circular.

3. A structural truss as set forth in claim 1 wherein said web member has a cross-sectional shape which is rectangular.

4. A structural truss as set forth in claim 1 wherein the brace has one or more fastener holes for receiving corresponding one or more said fasteners.

5. A structural truss as set forth in claim 4 wherein said fastener is distinct and non-integral with the brace.

6. A structural truss as set forth in claim 1 wherein the front and back sides of the web member have a spacing therebetween defining thickness confines of the truss, and wherein the brace is entirely within said thickness confines such that the brace does not interfere with stacking of multiple trusses.

7. A structural truss as set forth in claim 1 wherein the brace has a generally flat base and a pair of opposite side walls extending from the base generally transverse to the base, the base being secured to the web member by said one or more fasteners.

8. A structural truss as set forth in claim 7 wherein said side walls have inwardly turned ends.

9. A structural truss as set forth in claim 8 wherein said ends of the side walls turn at least about 180 degrees.

10. A structural truss as set forth in claim 7 wherein said web member has a cross-sectional shape which is circular, and the web member is received between the side walls.

11. A structural truss as set forth in claim 7 wherein said web member has a cross-sectional shape which is rectangular, and the side walls of the brace extend from the base and project outward from the web member.