| 摘要 |
<p>An electromagnetic lock for, for example, a door comprising an electromagnet (13) attached to the frame (12) and a magnetisable member (18) attached to the door the magnetisable member being attracted to the electromagnet when the door is in its closed or otherwise locked position, shoulder means (22, 23) being provided on or adjacent the electromagnet and the magnetisable member whereby if the door is forced to overcome the electromagnetic attraction the shoulder means engage to prevent unauthorised unlocking of the door.</p> |
