| 摘要 |
<p>The security bars for an opening in a wall (1) e.g. containing a window (23), are made in the form of two L-section grilles (20d, 20g) with vertical or crossing bars, hinged near their top and bottom ends to supports (4) on the inner surfaces of wall opening. The dimensions of the grilles are such that they are able to close together and be locked inside the window opening, which is covered by outer shutters (2d, 2g). In their open position the grilles lie over the shutters against the outer surface of the wall.</p> |
