AU650881B2 - A bottom chord for a roof truss - Google Patents

Description

7 6508

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT S F Ref: 183224 o 09 #9 99 o 9 9 99 to 1 0 1 9v 9* 9 9 9 9 99 .9 9 911

ORIGINAL

Name and Address of Applicant: 1.t ,1 I 4

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t t Uniframs Limted UJIFRAME LSQ PBOtLgT Level 41 arthpcint Toe, 3 Mart Strs Nieth Sydcy NSH 296+ 2000, A r a A Y S T R AL I A J I J L J Allan Meyer -0 113 uz! Spruson Ferguson,-Patent Attorneys 0 Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Actual Inventor(s): Address for Service: Invention Title: A Bottom Chord For A Roof Truss ASSOCIATED PROVISIONAL APPLICATION DETAILS [31] Application No(s) [33] Country [32] Application Date PK0505 AU 6 June 1990 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815/7 t7 A LOTTOM CHORD FOR A ROOF TRUSS The present invention relates to metal building frames and more particularly to the bottom chord of metal roof trusses.

Background Art s Metal roof trusses consist of a bottom chord which extends generally horizontally, and inclined members which extend upwardly therefrom to be joined at a position spaced from the bottom chord.

Previously known bottom chord members formed from rolled sheet metal, have been of a "U-shaped" transverse cross section so as to have upwardly facing edges. Such bottom chords are described and illustrated in PCT Application AU 88/00208 (USA Application 455208 filed 11 December 1989).

The above discussed bottom chord members have suffered from the disadvantage that the longitudinally extending side flanges tend to buckle under load.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate the above disadvantage.

Disclosure of the Invention There is disclosed herein a bottom chord member for a roof truss, said member being formed of rolled sheet metal and being of a generally "U-shaped" transverse cross section so as to have a pair of longitudinally extending co-extensive side flanges joined by a substantially planar base, the side flanges each having an upper portion and a lower portion, the upper portions being parallel to one another and the lower portions diverging from the upper portions to the base and wherein said base provides a generally planar lower surface and each flange projects from said surface to connect to a longitudinally 25 extending edge portion which also extends in a direction generally transverse of the flange so as to provide an upwardly facing upper surface, a terminal edge of each edge portion formed in a "C-shaped" transverse cross section so as to conceal said terminal edge; the base being knurled with a plurality of indentations for promoting adhesive bonding, said indentations being disLributed transversely across said base.

30 There is also disclosed a metal roof truss including a bottom chord member, a top chord member, a plurality of web members attached to and extending between the top chord and bottom chord members, and wherein said bottom chord member is formed of j: rolled sheet metal of generally "U-shaped" transverse cross section so as to have a pair of longitudinally extending co-extensive side flanges joined by a base, the side flanges each having an upper portion and a lower portion, the upper portions being parallel to one another and the lower portions divering from the upper portions to the base and wherein said base provides a generally planar lower surface, and each flange projects from said S [N:\LIBMM00124:LMM *1 }i

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F. t- 1A surface to connect to a longitudinally extending edge portion having a generally planar section extending in a direction generally transverse of the associated flange and parallel to the base portion so as to provide an upwardly facing upper surface, a terminal edge of each edge portion formed in a "C-shaped" transverse cross section so as to conceal said terminal edge; and wherein lower surface is knurled with indentations distributed transversely across the lower surface.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: 1o Figures 1 and 2 are schematic elevations of typical forms of a metal roof truss; Figure 3 is a schematic end elevation of a bottom chord member of a metal roof truss; and Figure 4 is a schematic bottom plan view of the member of Figure 3.

Description of the Preferred Embodiment In the accompanying drawings there is schematically depicted a bottom chord member 10 of a metal roof truss 20. The metal roof truss )r C t F Ct C CC

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[N:\LIBMM]001 24:LMM -2includes the bottom chord 10 joined to one or more top chords 21 by means of web members 22. The member 10 is formed of rolled sheet steel and is of a generally "U-shaped" transverse cross section. Accordingly the member 10 has a base 11 and a pair of generally co-extensive parallel side flanges 12. The side flanges 12 include inclined portions 13 which i connect with the base 11 and vertical portions 14 which extend generally Snormal to the base 11.

The base 11 has a generally planar lower surface 15 which is knurled so as to have a plurality of deformations in the form of indentations 21.

The upper end of each side flange 12 connects with a longitudinally extending edge portion 16 which includes horizontal portions 17 extending to the extremities 18 which are of a "C-shaped" transverse cross section S ,so that the edge 19 of each edge portion 16 is not exposed.

t 15 The indentations 21 aid in securing internal lining panels to the chord member 10 via adhesives. Still further, the indentations 16 aid in the use of threaded fasteners and nails since the threaded fasteners and nails do not "skid" along the surface 15 when penetrating the base 11.

The edge portions 16 stiffen the side flanges 12 to inhibit 20 buckling. However an unexpected advantage is the safety of the edge portion 16. By providing upwardly facing surfaces 17, tradesmen may walk along the chord members 10 with a certain degree of safety in comparison to previously known chord members 10 which have terminated with sharp 4 edges. A still further unexpected advantage is the concealment of the edges 19 which are not in a position to cut or snare electrical wiring.

When wiring is being installed, it is dragged across the chord members.

Previously known chord members with exposed edges have often cut the wiring rendering it dangerous.

JLH/LMM/447t

Claims (6)

1. A bottom chord member for a roof truss, said member being formed of rolled sheet metal and being of a generally "U-shaped" transverse cross section so as to have a pair of longitudinally extending co-extensive side flanges joined by a substantially planar base, the side flanges each having an upper portion and a lower portion, the upper portions being parallel to one another and the lower portions diverging from the upper portions to the base and wherein said base provides a generally planar lower surface and each flange projects from said surface to connect to a longitudinally extending edge portion which also extends in a direction generally transverse of the flange so as to provide an upwardly facing upper surface, a terminal edge of each edge portion formed in a "C-shaped" transverse cross section so as to conceal said terminal edge; the base being knurled with a plurality of indentations for promoting adhesive bonding, said indentations being distributed transversely across said base.

2. The bottom chord member of claim 1, wherein the edge portions each include is a generally planar section extending generally parallel to said base.

3. The bottom chord member of claim 2, wherein each edge portion has a longitudinally extending edge folded back upon itself so that the extremity thereof is located below the associated planar section.

4. A metal roof truss including a bottom chord member, a top chord member, a plurality of web members attached to and extending between the top chord and bottom chord members, and wherein said bottom chord member is formed of rolled sheet metal of generally "U-shaped" transverse cross section so as to have a pair of longitudinally extending co-extensive side flanges joined by a base, the side flanges each having an upper portion and a lower portion, the upper portions being parallel to one another and the lower portions divering from the upper portions to the base and wherein said base provides a generally planar lower surface, and each flange projects from said surface to connect to a longitudinally extending edge portion having a generally planar section extending in a direction generally transverse of the associated flange and parallel to the base portion so as to provide an upwardly facing upper surface, a terminal edge of each "1 4 30 edge portion formed in a "C-shaped" transverse cross section so as to conceal said terminal edge; and wherein lower surface is knurled with indentations distributed transversely across the lower surface. The roof truss of claim 4, wherein said base is provided with a plurality of indentations. o 35 6. A bottom chord member for a roof truss, substantially as hereinbefore described with reference to the accompanying drawings. U IBMM]OO124:LMM 4

7. A roof truss substantially as hereinbefore described with reference to the accompanying drawings. Dated 25 February, 1994 Uniframes Holdings Pty Limited Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [NWALIBMMJOO1 24IMM rt isA ABSTRACT A metal roof truss 20 for a building. The truss 20 has a bottom chord member 10 joined to top chord members 21 by means of web members

22. The bottom chord member 10 is of a generally "U-shaped" transverse cross section so as to have a pair of longitudinally extending side flanges 12 joined by a base 11. The flanges 12 are each provided at their upper ends with generally planar upper facing surfaces 17 which extend to "C-shaped" extremities 18. St 4 t a r S (.FIGURE 3) JLHILMM/447t