| 摘要 |
<p>A swinging device for controlling opening and closing of a shut-off valve or the like includes an oscillating crank which is pivoted with its one end to a nut reciprocating on a spindle driven by an electromotor via a gear transmission. The oscillating crank swings between two end positions and is provided with an elongated slot in which a prolongation of a coupling member projects in shiftable but non-rotational manner. In both end positions of the crank which correspond to the respective opening position and closing position of the shut-off valve, a maximum torque is exerted on the switch shaft because the distance of the point of articulation of the crank to the nut from the rotational axis of the switch shaft is at a maximum.</p> |
