| 摘要 |
987,076. Gas blast switches. ETABLISSEMENTS MERLIN & GERIN S.A. March 15, 1963 [March 19, 1962], No. 10304/63. Heading H2B. A circuit braker having a tubular arc passage 17 with gas evolving walls is provided close to the fixed contact 12 with a de-ionizing device 19, comprising closely spaced laminae, disposed at the entry to a gas accumulator 18. The arc releases gas in the passage 17 which is still closed by the moving contact 11 and it therefore flows through the cooler 19 to the accumulator 18. As soon as the moving contact 11 clears the end of passage 17 the gas escapes from the accumulator, again passing through the cooler, and extinguishes the arc. To prevent excessive pressures the passage 17 is apertured at 21. An electrode ring 22 connected by a resistor 23 to the fixed contact limits the restriking voltage. In the modification of Fig. 3 the aperture 21 is closed by a pressure sensitive valve 24 which carries an armature 28 attracted by a magnetic core 29 energized by the arc current and thus prevented from opening under gas pressure until a zero of the A.C. In an alternative form (Fig. 4, not shown) the moving contact is hollow and passage 17 contains a rod of gas envolving material, such as polyoxymethylene. The whole switch may be immersed in SF 6 the gas evolving surfaces being of P.T.F.E. |
