| 摘要 |
<p>A switch for making and breaking a connection between a load circuit and a power line, with two parallelogrammatic linkages terminating in scissorlike contactor pairs, has limitedly swivelable and/or extensible cross-links interconnecting aligned pivotal junctions of the two linkages to provide them with a certain relative mobility. In an operating position, part-cylindrical armatures detachably secured to the two contactor pairs grip respective portions of an elongate countercontact fixedly suspended between a pair of rings attached to the power line, this countercontact comprising a metallic supporting tube also provided with part-cylindrical armatures in the region of the contactor pairs. Each armature may comprise several metallic layers on a base of copper, namely an inner layer of silver, a protective layer of tin on top thereof, and an outer silver layer. The armatures could also be made, at least in part, of a scorchproof material such as silver/cesium oxide.</p> |
