| 摘要 |
An electric circuit-breaker comprises a pivotable knife contact (4) movable into and out of engagement with a fixed contact (2) and an annular arc electrode (5) surrounded by a coil (6) connected electrically in series between the arc electrode (5) and the fixed contact (2), the arrangement being such that during the opening of the circuit-breaker, an arc is first formed between the fixed contact (2) and the knife contact (4) and thereafter between the knife contact (4) and the arc electrode (5), so that the magnetic field created by the coil (6) causes the arc to rotate so that it is extinguished. In order to provide a reliable breaking over the whole current range, the knife contact (4) is so arranged with respect to the arc electrode (5) that the tip (4c) thereof makes contact (at 8) with the arc electrode (6) during the opening of the circuit-breaker. <IMAGE> |
