| 摘要 |
<p>The trellis beam for a pre-fabricated building ceiling has two planes defined by three longitudinal rods forming a head rod (1) and two base wires (2,3) and forming an angle between them. Each of the plane frames (4,5) is defined by an undulating wire which is connected to the top rod at their top curvature and to the lower rod at their lower curvature.</p> |
