| 摘要 |
PCT No. PCT/CA92/00514 Sec. 371 Date Mar. 1, 1995 Sec. 102(e) Date Mar. 1, 1995 PCT Filed Nov. 25, 1992 PCT Pub. No. WO94/05872 PCT Pub. Date Mar. 17, 1994.A metal member having at least one edge formation, and a web extending from the edge formation, a plurality of generally triangular openings formed in the web at spaced intervals, the triangular formations being alternately reversed relative to one another, a plurality of generally diagonal struts extending between adjacent triangular openings, edge portions along either edge of the web portion, with the struts extending from one said edge portion to the other and merging integrally therewith, flange formations formed from the web around the generally triangular openings, and lying at an angle thereto, whereby to form the diagonal struts with a generally channel shaped cross section, and forming intermittent flanges along the web edges at the base of each triangular opening, the triangular openings defining generally curved corners, and, generally three-sided indentations formed in the web edge at the roots of each of the diagonal struts.
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