| 摘要 |
The invention disclosed is a knife blade switch 2 having copper jaws 10 and a copper blade 4 with a steel end-plate 6 fastened to the free end of the blade, the steel end-plate having a higher resistivity than the resistivity of the copper blade and copper jaws. As the copper blade is withdrawn from the copper jaws, the steel end-plate of the blade remains in contact with a higher resistivity steel jaw-spring mounted on and electrically connected to the copper jaws. The connection of the steel end-plate 6 of the blade with the steel jaw-spring 12 imposes a greater resistance path for the current flowing through the switch than through the copper blade 4 and copper jaws 10, so that an arc formed at the plate and jaw-spring has a diminished current, over what would otherwise occur with a copper blade and jaws, when the contact separation occurs. |
