| 摘要 |
<p>The safety device for roller shutters, esp. in front of large openings, prevents them from moving downwards of their own accord, which could cause damage or mutilation. The end slat (2) is connected to an element (17), which can pivot. This acts in conjunction with a slat (12, 13) parallel to the end slat's track, made up from a number of attachments (15, 16) with intervening spaces (14). With normal lowering of the shutter these attachments set the element in an oscillating motion in and out of the spaces, but excessively rapid downward movement causes the nearest attachment to block the outward swing and thus prevent any further drop.</p> |
