摘要 |
In connection with synchronous closing or opening of three-pole circuit breakers, the desired time shift between the instants of contact make or contact break in the different phases can be achieved mechanically by a suitable choise of arms and links in the mechanical system interconnecting the contacts and the operating device. The necessary time difference between the instants of switching, with retained positions of open and closed contacts, can be achieved in mechanism with a toggle joint (4, 51) which is extended to a greater or smaller extent in the three poles. |