摘要 |
<p>An electrical switch for protecting equipment from oerheating has a bimetallic element (16) which breaks electrical contact at a threshold temperature and a resetting member (40) which restores it when depressed manually. A bistable, over-centre contact member (24) is arranged such that initial movement of the resetting member moves the contact member over-centre, but also displaces the contact member, leaving the electrical contacts disengaged. Electrical contact is only restored on release of the resetting member. In this way the risks of manual tampering with the switch are reduced.</p> |