摘要 |
A gas-blast switch having a pump cylinder conjointly movable with a movable contact element, the pump cylinder enclosing a pump chamber containing extinguishing gas and feeding a blast nozzle. Within the pump cylinder there is movably arranged a pump piston which, during the course of the cutoff stroke, displaces the extinguishing gas out of the pump chamber through the blast nozzle. In order to utilize the drive energy at the start of the cutoff stroke extensively for accelerating the movable switch elements and to somewhat delay in time the compression of the extinguishing gas in the pump chamber, likewise requiring the drive energy, there is hingedly connected at the pump piston one element of a toggle lever which is fixedly hinged at its other element and assumes a bent position in the cuton position. The toggle lever is guided by a guide element coupled with the movable contact element. This guide element, during the course of the cutoff stoke, initially intensifies the bent position of the toggle lever prevailing during the cuton position, then reduces and finally again intensifies such bent position of the toggle lever. As a result, the pump piston, during a cutoff stroke, initially moves in the same sense, then in the opposite sense, and finally again in the same sense with the pump cylinder.
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