Metal roof truss having generally s-shaped web members

Abstract

The metal truss assembly disclosed herein is made from generally U-shaped metal chords and multiple generally S-shaped web members extending between the chords. A typical truss assembly has a pair of elongated, opposed, diverging metal upper chords and a lower chord, with the chords each forming generally U-shaped channels defining an interior chord space. A plurality of elongated metal web members extend between the upper and lower chords, with each of the web members extending into the interior space of an upper chord and the lower chord and attached to the chords. The web members, as taught herein, have a generally S-shaped cross-section. The shape of the web members is an advancement of prior art web members.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 12 / 243,813 filed on Oct. 1, 2008, still pending.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicableREFERENCE TO MICROFICHE APPENDIX[0003]Not applicableTECHNICAL FIELD[0004]The invention relates to a metal roof truss having an upper and lower chord and a plurality of web members extending between the chords, and more particularly, to such a truss wherein the web members are of a generally S-shaped cross-section.BACKGROUND OF THE INVENTION[0005]Metal roof trusses may take on various shapes, but the most commonly encountered shape is defined by two upper chords joined at adjacent ends and each connected to a lower chord to create a generally triangular truss. Extending between the upper and lower chords are a plurality of web members.[0006]The prior art teaches various cross-sectional shapes for the upper and lower chords, including general...

AI Technical Summary

Benefits of technology

[0014]The web members preferably have a center of gravity and a center of shear which coincide. This improves the strength and performance of the web members. Further, the center of gravity and center of shear preferably fall within the cross-sectional area of the web member.

Problems solved by technology

A C-shaped member is prone to flexural torsional buckling for any given gauge or thickness of metal in comparison to a tubular or S-shaped web member.

The use of heavier gage metal or significant lateral bracing increases the cost of manufacture and production of the metal truss.

Hot-rolled members are more expensive to manufacture than cold-rolled members.

Similarly, the additional step of welding cold-rolled tubulars adds cost over cold-rolled tubulars without welding.

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