| 摘要 |
<p>A beam is formed from a rectangular strip (11) of metal having Laser cut parallel longitudinal edges by, first, bending the strip (11), using a jig arrangement, about two fold lines respectively inset from the longitudinal edges (13A, 13b) of the strip (11), such as to create two upstanding marginal flanges. Next, the so-flanged sheet is bent about a longitudinal central fold line (35) such as to create a longitudinally-folded sheet of V-form cross-section, but with in-turned flanges at the mouth of the V-form section. Finally, the V-form folded sheet is braced using either a metal strip (39) or external constraint members that embrace the V-form folded sheet at intervals therealong. The beam may serve as a trackway means for a machine tool, a tool-carrying carriage (57) having wheels rotatable about vertical axes, with the wheels (61,63) in running contact with the trackway means at surfaces adjacent to the bend positions of the flanges (33A, 33b).</p> |
