| 摘要 |
A boom useful in dragline excavators, cranes and similar machines has a set of longitudinal chords defining a length along the boom and a plurality of lacings connecting the chords. These chords and lacings define a first boom section having a first pair of laterally spaced polyhedron subsections and a second boom section having a second pair of laterally spaced polyhedron subsections, the second pair of subsections being positioned longitudinally with respect to the first pair of subsections. In one embodiment, the polyhedron subsections of each boom section have transverse cross sections in the form of right triangles, with one triangle inverted with respect to the other to form a rectangular-shaped boom. Also, one boom section is reversed end to end with respect to the other boom section to have an inner chord in a subsection on one side of the first boom section in alignment with an inner chord of a subsection on the opposite side of the second boom section.
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