摘要 |
<p>A safety system, such as for detecting obstructions in a window opening having a motor-slidable window glass (32) and for arresting the window glass in the presence of such an obstruction, comprises a glass-receiving channel (34). The base (48) defines a hollow chamber (60) incorporating a sensor (62). The sensor supports two substantially parallel longitudinally extending force-responsive sensing units (12, 14) each positioned immediately adjacent to a respective one of the side walls (44, 46) of the channel (34). If an obstruction in the window opening is carried upward by the slidable window pane (32), it will apply a force to the distal edge of one or both of the side walls (44, 46) and this force will be transmitted to the respective sensing unit (12, 14). Electrically conductive strips of the relevant sensing unit (12, 14) move into contact to produce an electrical signal which arrests the window glass. A third, similar, sensing unit (13) of the sensor (62) is positioned to produce a corresponding electrical signal when a force is applied to it by the distal edge of the closing window glass. This is used to indicate completion of travel of the window glass.</p> |