| 摘要 |
<p>The switch comprises a cable extending along the door edge enabling detection of obstacle at any height. The safety device for an automatic door comprises a sensing bar intended to detect any obstacle obstructing closure of the door. This incorporates a cable (11) which extends in a direction which is transverse to the direction of movement of the door, and which has one end fixed securely to the door. The second end of the cable is linked to a core (17) which is mobile w.r.t. the door in a direction parallel to the cable. This core moves against the action of a spring (23). The core has a cylindrical shape, and includes two rings (18,19) of conducting material around its outside surface at its ends. These are linked internally by diodes, and brushes (15,16) make contact with the rings externally. If the core is moved, the electrical properties of the circuit are changed and detected.</p> |
