| 摘要 |
<p>1. A turning drive comprising a self-locking worm gear, the worm (1) of which is axially floatingly pivoted and on both sides spring biased in axial direction, a first and a second limit switch (8, 9) each for switching-off in one direction of rotation in the case of exceeding a first predetermined force being actuable by said worm via corresponding actuation surfaces (13), characterized in that a third limit switch (10) being arranged in a greater distance with respect to the actuation surface (13) for the first limit switch (8) corresponding to a second greater predetermined force and a bridging switch (14) for the first limit switch (8) are provided, said bridging switch being actuable by a part (3), which is moved by said worm gear, shortly before reaching the end position of the said part.</p> |
