| 摘要 |
1,264,927. Gas blast circuit breakers. SIEMENS A.G. 13 March, 1970 [14 March, 1969], No. 12291/70. Heading H1N. A circuit breaker has two nozzle contacts 3, 4, the cross-sectional area of their adjacent end regions being substantially four times the area of the associated orifice, also a bridging contact 6 and for compressing an arc quenching medium an associated piston and cylinder arrangement. The closed and open positions for the circuit breaker are shown on the right and left respectively of the central axis of the chamber 1 filled with the arc quenching medium, e.g. SF 6 gas. Contact 4 is connected to piston 14 by means of rods 15, 16 and further coupled via pin 18 and link 19 to crank 20. A drive rod 23 is connected to blast piston 11, formed integrally with tube 10 of insulating material to form a cylinder, via linkage 25, 26, 27, 29. In the " opening " operation drive rod 23 moves from right to left causing the blast piston 11 to move downwards compressing the arc quenching medium, and the contact 4 to move, together with piston 14, towards the contact 3 and into the position shown by the dotted lines 4<SP>1</SP>, 14<SP>1</SP>. In this position the bridging contact 6, made up of resilient segments and having an arcing ring 7 at its tip, leaves contact 3. An arc is formed which is subject to a blast of sulphur hexafluoride gas, which has by this time been compressed to half its original volume between the blast piston 11 and the fined piston 14. After the arc is quenched the contact 4 and the piston 11 move back to the open circuit position shown. In Fig. 1 (not shown), the contact 4 is fined and the blast piston not tapered. The contact surfaces may be made of graphite. |
