摘要 |
<p>The invention relates to a stepping switch with vacuum switching tubes (22) according to the preamble of the first claim. According to the invention, the general inventive concept consists in providing a second cam disc (3) which is rotationally fixed to the driveshaft (1) in addition to the first cam disc (2) which is rotationally fixed to the driveshaft (1) and which is known from the prior art for applying the force of the opening stroke of the contact system of the vacuum switching tubes (22). The second cam disc exerts a sufficiently high closing force onto the movable follower of the vacuum switching tubes (22) via a spring-lever system provided on the rocker arm arrangement (6) even in the event of a short-circuit stress and additionally allows a tolerance compensation of the contact system.</p> |