| 摘要 |
<p>The switch as in the main patent, has a double switching system, with a blocking device so that a drive motor will not be damaged by incorrect operation. The blocking device consists of a slider (30) which spans the spindles of both switching arms (17). This is swung in one direction by movement of one arm, and then in the opposite direction when the other arm is moved. This movement blocks the second arm after the first arm has been moved and vice versa. The slider can be T shaped with the corners removed from the vertical arm and its length is greater than the distance between the arms. In another design, the slider is rectangular with a spring arm projecting from wach top corner. In both cases, the slider is pushed sideways by the movement of a switch arm.</p> |
