摘要 |
A vacuum interrupter, an envelope of which includes a pair of electrical lead rods of copper or copper-based alloy, one lead rod being brazed vacuum-tight to one end plate via a first tubular sealing member fitted onto one rod, and a bellows surrounding another lead rod, an outer end of the bellows being joined vacuum-tight to another end plate and an inner end of the bellows being brazed vacuum-tight to the other lead rod via a second tubular sealing member fitted onto the other lead rod. Each sealing member is made of an iron-based alloy and has an inner wall including a groove retaining solid brazing metal and two vacuum-tight brazing surfaces opposing each rod across a small clearance. The molten brazing metal permetates through the clearance due to wetablility and capillary action without erodingly diffusing into the opposing surfaces of the lead rods and the first and second sealing members. |