| 摘要 |
A movable contact element is secured at the end of a thrust rod and therefore can be brought into and out of engagement with a fixed contact element. The free end of the movable contact element is surrounded by a blast nozzle which is likewise secured to the thrust rod. The inlet of the blast nozzle is operatively connected with a pump chamber containing an extinguishing gas and which can be pressurized during the course of a cut-off stroke of the gas-blast switch. This pump chamber is surrounded at its circumference by a cylinder which is displaceably guided upon a stationarily supported piston. To reduce the mass of the parts which are to be accelerated at the start of the cut-off stroke, the blast nozzle itself is constructed as a second piston situated opposite the first-mentioned piston and displaceable relative to the cylinder between two end positions. Means are provided in order to displace, during a cut-off stroke, the cylinder in the same direction or sense as the movable contact element, but however, through a smaller path than such movable contact element.
|
