| 摘要 |
<p>A cross member is provided with a flange which is placed in the edge kerf of ceiling boards. The cross member supports the ceiling boards in position. A joint structure is provided to connect together two adjacent cross members. The joint structure is so arranged with a slot and a protrusion that the two cross members can be somewhat adjustable in length and have a positive engagement between the slot and the protrusion.</p> |
