Structural member

Abstract

A truss including a first support member, at least one second support member and a connector connecting the support members. The first support member has a first substantially planar portion. The second support member has a non-planar cross section substantially along a length thereof and an end with a second substantially planar portion. The connector secures the first and second substantially planar portions.

Description

FIELD OF THE INVENTION

[0001] The invention relates to a structural member for construction of buildings such as houses. The invention has particular but not exclusive application in use as a chord for forming a roof truss for a building.

PRIOR ART

[0002] A metal roof truss is commonly constructed with box-section chords and C-section web members. The box-section chords are formed by two C-sections individually roll formed and then further fabricated by dimple formation for locating and/or fastening by welding, riveting, hole punched and bolted or screwed to close the two C-sections. The fabrication of the section is a specialized operation and adds additional cost and time to the manufacture of a chord.

[0003] Open sections are generally quicker and cheaper to manufacture than box-sections comprising two C-sections, but they lack the strength and stiffness required for chords. Thus, whenever open sections, such as channel and Z-sections are used in the fabrication of building frames and roof trusses, additional precautions such as providing oversized sections or additional structural support must be taken to compensate for their inherent strength deficiencies. This of course increases the cost of many structures formed therefrom.

[0004] In addition, effecting the joints between top and bottom chords and between web members and chords mostly requires specialized joining members or shaping for welding which adds to the cost and complexity of such structures.

SUMMARY OF THE INVENTION

[0005] A truss or other structural member formed from the combination of an open structural member and a chord having a c-shaped, closed or elliptical cross section and/or a second open structural member.

[0006] In one aspect the invention broadly resides in an elongated open structural member having a cross-section including a minor flange, a major flange and a web interconnecting the flanges and having a section axis at right angles to the longitudinal axis of the structural member and passing through the flanges and wherein:

[0007] the web includes a linear portion substantially coincident with the section axis and a divergent portion which extends to one side of the section axis;

[0008] the minor flange extends to the one side of the section axis;

[0009] the major flange extends from the divergent portion to the opposite side of the section axis, and

[0010] the section configuration being such that an inverted and reversed corresponding open structural member is nestable within the open structural member with their respective linear section portions alongside one another and with each minor flange located in an abutting relationship against the underside of the adjacent major flange.

[0011] The linear portion may be any suitable length but preferably the linear portion is extends along a major portion of the section axis between the flanges. The term “suitable” is qualified by the particular use of the open structural member and where a corresponding member is used the length of the linear portion suitably enables overlap of the linear section portions or portions thereof.

[0012] The divergent portion may have any suitable shape. The divergent portion may be curved, straight, or comprise a series of straight segments. In a preferred embodiment the divergent portion is a single straight portion and the major flange extends at an acute angle from the divergent portion.

[0013] The linear portion connects to the minor flange at its end opposite the divergent portion. Preferably the minor flange extends from the linear portion at an angle of substantially 90 degrees. Alternatively, the linear portion may include a second divergent portion which extends to the minor flange. The second divergent portion may be curved, straight, or comprise a series of straight segments.

[0014] The minor flange is preferably shorter than the major flange and most preferably is shorter than the section of the major flange which extends between the section axis and the end of the major flange remote from the divergent portion, and hereinafter referred to as its “free edge”. Preferably the intersection with the section axis occurs about midway across the-major flange.

[0015] Preferably the flanges are substantially flat or at least parts which are substantially diagonally opposite with respect to the section axis are substantially flat. Preferably the flanges or at least the flat parts are substantially parallel.

[0016] Preferably the open structural member includes a limitor to restrict lateral movement with respect to the section axis of connected members along the section axis. Preferably the limitor is a return flange extending along the free edge of the major flange.

[0017] The major and/or the minor flanges preferably both terminate in a return flange. The return flange preferably returns substantially parallel to the section axis. Preferably the return flange of the major flange is spaced further from the section axis than the free edge of the minor flange so that a reversed and inverted corresponding open structural member may nest within the structural member.

[0018] The open structural member is preferably asymmetrical in shape and allows the nesting of an inverted and reversed corresponding open structural member with the minor flange of one open structural member locatable within the major flange of the other open structural member and overlapping of the linear section portions.

[0019] The invention in a further aspect broadly resides in an elongated open structural member having a minor flange, a major flange and a web interconnecting the flanges and having a planar web portion extending at right angles to the minor and major flanges, and wherein:

[0020] the web includes a divergent portion which extends to one side of the planar portion;

[0021] the minor flange extends to the one side of the planar portion;

[0022] the major flange extends from the divergent portion to the opposite side of the planar portion;

[0023] the minor flange and the major flange each have a return along their respective free edge, and wherein

[0024] the configuration being such that an inverted and reversed corresponding open structural member is locatable with its planar portion alongside the planar portion of the structural member and each minor flange including its return being locatable within the confine defined by the adjacent return flange of the major flange.

[0025] In another aspect the invention resides in a chord member for a truss, each chord member of the truss being an open structural member as described above whereby the chord member may be disposed with its major flange outermost and with interconnections between intersecting chord members being made by extending the web and minor flange of one intersecting chord member across the web and minor flange of the other chord member with the webs overlying one another enabling through fastening together. In such arrangement the webs overlap at joints for connection to one another such as by bolting or screwing or welding and, if desired disposed with their minor flanges nested within the major flanges of the opposing chord member.

[0026] It is also preferred that the chords of the truss are interconnected by truss members which may be open section members suitably terminated for web to web connection to the webs of the top and bottom chord members.

[0027] The assembled truss with the open structural member forming the top and bottom chord members with C-section truss members preferably has the chord members proud of the truss members thereby allowing stacking of the assembled truss and transportation of the stacks without risk of damage to the truss members by the overlying chord members. In contrast conventional box section chords have C-section truss members joined at their flat surfaces thereby causing the truss members to be proud of the chord members and exposing the truss members to damage during stacking and their transportation.

[0028] In a further aspect the invention broadly resides in a composite beam formed by the nesting of two open structural members as described variously above in an inverted and reversed orientation with respect to each other with the minor flange of one member located within the major flange of the other member and overlapping of the planar portions and fastening means connecting the open structural members together.

[0029] The open structural members may be prevented from lateral displacement with respect to one another by the fastening means but preferably they include returns along the free edges of the major flanges which restrain lateral displacement of the open structural members with respect to one another.

[0030] Preferably the nesting of the open structural members as described above forms two closed sections thereby providing strength to the beam.

[0031] A further aspect of the invention includes a truss including a first support member having a substantially planar portion; at least one second support member having a non-planar cross section and an end with a second substantially planar section; and a connector securing the first substantially planar section to the second substantially planar portion. The second support member may have a C-shaped or elliptical cross section. Also, the second substantially planar portion is a crimped version of the non-planar cross section. The connector may be a bolt or other suitable connector well known in the art. The end of the second support member may have third and fourth substantially planar portions arranged at angle to the second substantially planar portion. Further, this embodiment is not limited to one second support member and may contain a plurality of second support members connected to the first support member by the connector.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Several typical embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

[0033] FIG. 1 is an end elevation of an elongate open structural member;

[0034] FIG. 2, 3, 4 are perspective views of the member;

[0035] FIG. 5 is an end elevation of two members nested in reverse and inverted orientation with respect to each other;

[0036] FIG. 6a is a front elevation of an assembled truss with open structural members as top and bottom chord members;

[0037] FIG. 6b-g shows various connections on the truss shown in FIG. 6a;

[0038] FIG. 7a-c are views of the interconnection of two open structural members;

[0039] FIG. 8a-c are views of different attachments of a C-section truss members to a chord;

[0040] FIG. 9a-c show alternative connections between chords and truss members;

[0041] FIG. 10a-c shows an alternative structural member; and

[0042] FIG. 11a-b shows interconnections of closed section chord members and open structural members.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] With reference to FIGS. 1, 2, 3 and 4 there is shown an elongate open structural member 10 having a minor flange 12 and a major flange 13 separated by a web 14. A longitudinal axis 11b of the member 10 is shown in FIG. 2. The web 14 includes a planar portion 17 and a divergent portion 18. A section axis 11a is coincident with the linear portion 17. The minor flange 12 extends from the planar portion 17 at 90 degrees. The minor flange 12 includes a return flange 15. The return flange 15 is parallel to the section axis 11a. The divergent portion 18 diverges from the section axis 11a at an acute included angle indicated by alpha. The divergent portion 18 is connected to the major flange 13. The major flange 13 includes a broad planar flange portion 19 which is connected to the divergent portion 18 forming an acute included angle. The major flange 13 also includes a return flange 20 parallel to the section axis.

[0044] As shown in FIG. 5, two elongate open structural members 30, 31 as described above are able to be nested with one member being in reverse and inverted orientation with respect to the other. To effect nesting minor flanges 32a and 32b, are located within major flanges 33b and 33a respectively in abutting relationship. In this position the respective web portions 34a, 34b partly overlie each other thereby allowing fasteners to join both members 30, 31 to prevent lateral movement. The abutting relationship of the respective flanges 32a, 32b, 33a, 33b prevents movement along the section axis. The nesting of the two elongate members forms two closed sections 35, 36 which provide strength and stiffening to the composite member.

[0045] Roof trusses 40 as shown in FIGS. 6a-g are constructed with elongate open structural members forming top and bottom chords 41, 42 and C-section truss members 43. The connection of the top chord 41 to the bottom chord 42 is shown in FIG. 6b. The major flanges 44, 45 of the top and bottom chords 41 and 42 respectively are outermost. The minor flange 46 of the top chord 41 is partially located and confined in major flange 45. The rearward flat side 47 of top chord 41 partly overlaps frontward flat side 48 of the bottom chord 42. There is shown an intermediate connection plate 49 between sides 47 and 48. The connection plate 49 is attached to the bottom chord 42 by bolts 50, 51 and to the top chord 41 by bolts 50, 52. An alternative connection is shown in FIG. 9c where top chord 60 is bolted to bottom chord 61 at 62.

[0046] Connections of the C-section truss members 43 to the chord members 41, 42 are shown in FIGS. 6c, 6d, 6f. In FIG. 6d the truss members 43 are crimped and joined to the-top chord 41 by bolt 70. In FIG. 6e the truss members 43 are attached to the bottom chord 42 by bolt 72. The underlying truss members 43 are at least crimped to accommodate the connection. The connection shown in FIG. 6c has the truss member 43 connected by bolt 71 to the bottom chord 42. The chords 41, 42 are proud of the truss members 43 in the truss 40. A preferred connection includes the planar surface of the crimped end of the truss member secured to the planar portion 17 of the web 14.

[0047] The apex 80 of the truss 40 is shown in FIGS. 6f and 6g. An apex plate 81 serves to connect top chords 41 by bolts 82. The apex plate 81 has recessed ribs 83 to provide additional stiffening. The apex plate 81 also has a recess 84 for the location of a C-section truss member 43. The C-section truss member 43 is connected to the apex plate 81 by bolt 85. Alternative connections in an apex are shown in FIG. 9a and 9b. In FIG. 9a top chords 63 and C-section truss members-64 are connected by bolt 65. Similarly in FIG. 9b the top chords 66 and C-section truss member 67 are connected by bolt 68.

[0048] In FIG. 7a-c there is shown chords 90,91 with major flanges 92, 93 outermost and minor flange 94 of chord 91 located partially within the major flange 92 of chord 90.

[0049] In FIGS. 8a-c there is shown attachment of crimped C-section truss members 95 to elongate open structural member chords 96 by bolts 97. The C-section truss member 95 has end 98 crimped presenting a flat surface 99 for connecting to the chord 96. The flat surface 99 is attached to the side of the web portion 100 opposite the narrow flange 101.

[0050] FIGS. 10a-c depict different embodiments of open structural member 10.

[0051] FIGS. 11a-b show another embodiment of a structure 110, such as a roof truss or other structures well known in the art. The structure 110 includes an open structural member 10 connected to two truss members 112 with a single bolt 114.

[0052] Truss members 112 have a closed or substantially elliptical cross-section formed by sidewall 112a and an area of void space within the sidewall 112a.

[0053] As shown in FIG. 11a, the elliptical truss members 112 have an end 116 which is crimped such that the sidewall 112a of the elliptical truss member 112 is compressed to decrease the space therebetween.

[0054] FIG. 11b, which is a top view of FIG. 11a also shows the crimped nature of the ends of elliptical truss members 112.

[0055] Also as shown in FIGS. 11a-b, the crimped end 116 has two side portions 118 and 120, which in a preferred embodiment form an angle &bgr; with a center portion 122. The angle &bgr; at which the side portions 118 and 120 bend with respect to the center portion facilitates securing multiple truss members with a single bolt 114.

[0056] The center portion 122 is relatively planar and is secured to the planar portion of another structural member by a single bolt. Center portion 122 has sidewall 112a which in a preferred embodiment are closer together than the sidewalls 112a in the side portions 118 and 120. The angle &bgr; at which the side portions 118 and 120 may bend with respect to the center portion facilitates securing multiple truss members with a single bolt 114.

[0057] Another feature of the connection of the truss members 112 to the open structural member 10 includes the substantially planar portion 17 of open structural member 10 abutting the substantially planar surface of truss member 112.

[0058] Although FIGS. 11a-b include two structural members 112, the number of structural members which may be attached is not limited to two and may be one or several. Further, the invention is also not limited to the use of a bolt and other suitable connectors well known in the art may be used. Also, although the structural members are shown connected to open structural member 10 which has a minor flange, major flange and divergent portion, connection to this type of structural member is not necessary. Rather, structural members 112 may be connected to any structural member known in the art having a substantially planar surface.

[0059] The embodiment described above provides a number of advantages including efficient roll forming for chord production; provision of a strengthened and stiffer open section member chord with proper orientation of the major flange outermost; the ability to treat or coat the entire chord or composite beam or truss having open sections prior to use; compact truss stacking with chords being proud of truss web members thereby minimizing damage to the truss members during transportation and reducing transport and storage costs; the ability of the chords to overlap for interconnection while maintaining the overlapped chords in line one above the other for symmetry of the truss and to be easily fastened together at terminations.

[0060] It will of course be realized that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

Claims

1. A truss comprising:

a first support member having a first substantially planar portion;

at least one second support member having a non-planar cross section substantially along a length thereof and having an end with a second substantially planar portion; and

a connector securing the first and second substantially planar portions.

2. The truss of claim 1, wherein the non-planar cross section is C-shaped.

3. The truss of claim 1, wherein the non-planar cross section is elliptical.

4. The truss of claim 1, wherein

the second substantially planar portion is a crimped version of the non-planar cross section.

5. The truss of claim 1, wherein

the first substantially planar portion is adjacent the second substantially planar portion.

6. The truss of claim 1, wherein

the connector is a bolt;

the first substantially planar portion has a first aperture;

the second substantially planar portion has a second aperture; and

the bolt is within the first and second aperture.

7. The truss of claim 1, further comprising:

a plurality of second support members connected to the first support member by the connector.

8. The truss of claim 1, wherein the end of the second support member has a third substantially planar portion and a fourth substantially planar portion, arranged at respective angles to said second substantially planar portion.