| 摘要 |
<p>Two tubular straight frame members, of identical rectangular cross-section, are adapted to be secured to opposite parallel sides of a building aperture and a rigid rod is insertable at both ends into rod-receiving holes made in the inwardly-facing walls of said frame members to extend across the aperture. This inwardly-facing wall, and also the front wall of each frame member, is provided with a pair of screwdriver-receiving holes made on either side of the rod-receiving hole. The two remaining walls of each frame member are provided with screwreceiving holes in respective axial alignment with the screwdriverreceiving holes. Thus, the frame members can be selectively fastened to the transverse or to the outwardly-facing surfaces of the aperture sides. In an alternative embodiment, one frame member is hingedly secured to one side of the aperture, while the opposite frame member is provided with a locking device, whereby the entire grille can be swung outwardly of the aperture.</p> |
