| 摘要 |
<p>A gas-blast switch preferably suitable for the switching of medium voltage has two switch pieces interacting in an insulating gas filled housing. A fixed switch piece is provided with a hollow space which is connected via channels to a pressure reservoir coaxially encircling the switch pieces. The pressure reservoir during switching-off, can be connected to an arc chamber terminated at least partially on its outer side by an insulating body. In this switch, a build up of pressure which is adequate to quench the arc is to be achieved at low currents by simple means and an excessive build up of pressure at high currents is to be avoided. This is achieved when the insulating body is made as an insulating nozzle and has a gas inlet, which can be connected to the pressure reservoir, and a gas outlet which is located between a narrow point of the insulating nozzle and the free end of the fixed switch piece. This gas outlet is connected via further channels to an expansion space and, during switching-off, is cleared by the movable switch piece before the gas inlet.</p> |
