| 摘要 |
PURPOSE:To prevent the thermal after effect due to arcs by arranging a pair of electrodes face to face so that the inclination directions of multiple grooves provided on arc drive sections are made opposite to each other and making the inner diameter size of a coil larger than the outer diameter size of the electrode. CONSTITUTION:Multiple grooves 14d and 15d inclined against the axial direction are provided in the peripheral direction on cup-shaped cylinder sections of arc drive sections 14b and 15b, and back faces of contact sections 14a and 15a are fixed to the opening ends. A pair of electrodes are arranged face to face so that the inclination directions of the grooves of the arc drive sections are made opposite to each other. As a result the magnetic rotary driving force along the peripheral direction is applied to arcs generated on protruded contact pieces 14c and 15c by the current flowing through the drive sections 14b and 15b, and arcs are not concentrated. They are distributed arcs by the vertical magnetic field, arcs are always moved, thereby the thermal after effect reducing the breaking performance does not occur on part of the contact pieces 14c and 15c. |
