| 摘要 |
An improved vacuum type circuit interrupter rated at 50 mva and for use at a voltage level of 4.8 KV and above comprises a constant diameter hollow cylindrical copper envelope into which a stationary and movable OFHC copper contact rods extend. Each contact rod is provided at its tip with a copper-bismuth alloy contact. A pump-out port is provided through the stationary contact rod. In one embodiment, one end of the envelope is provided with a substantially flat ceramic end plate which has a central opening for accommodating the stationary contact rod. A thin Kovar sealing ring is disposed between the envelope and the outer periphery of the ceramic end plate and a thin Kovar sleeve is disposed between the end plate and the stationary contacr rod. The other end of the envelope is provided with a hollow cylindrically shaped ceramic end tube. A thin Kovar ring is disposed between the envelope and the outer periphery of the ceramic end tube. A copper mounting plate having a central opening is secured to the outer end of the ceramic end tube and a cylindrical bellows surrounds the movable contact rod and is secured between the mounting plate and the movable contact rod. Disk-like shields made of copper or nickel are disposed against shoulders on the two contact rods to confine arc products. In a second embodiment of the invention, a ceramic tube is used instead of the flat ceramic end plate.
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