| 摘要 |
<p>The grille is formed from two sets of perpendicular bars enclosed by a frame. The bars are fitted together by force fitting the bars of one set into slits in the bars of the other set from above. The inverted J or U section elements of the frame are similarly fitted into slits in the bars, with the interior leg of each element being inserted and deformed towards the other leg to lock the assembly together. The bars have upper recesses which receive the webs of the elements so that the latter do not project above the bars. The outer legs of the elements typically engage the ends of the bars.</p> |
