| 摘要 |
<p>An electrical contactor comprises fixed contacts 34 on each side of a fixed member 14 interposed between an odd number, such as three, of moving arms 29,22 each having a movable contact 36 engaging with a fixed contact 14. When the contacts close current flowing through the arms produces a force which urges the arms together increasing a force between the fixed and movable contacts. Although a number of arms on one side of the fixed member, e.g. one, is different from the number on the other side, e.g. two, the overall lateral extents of the arms at each side of 15 the fixed member may substantially match. Arms 20,22 can have a distal extension tang 45 biassed by pin (fig 2a, 62) on an actuating carriage 44 against tilt to maintain parallel seating of the contacts and reduce bounce. The contacts can be actuated by a dual-latching electromagnetic actuator 42 by a wedge 60 that is on carriage 44 and between contact arms 20, 22. One of arms 20 can be pre-set to lead another arm that is preset to lag, so that the leading arm closes before the lagging arm. A leading arm can be wider than a narrow lagging arm. The contactor can have two sets of contacts, be used to disconnect an electrical meter and withstand high fault currents.</p> |
