| 摘要 |
<p>The device has two guiding rails (1, 2) fixed one above the other along a trajectory. A frame has a rear side on which two bearing wheels (4, 5) are projected, where the rail (1) is locked between the wheels (4, 5). The rear side has another bearing wheel (8) supported on an upper part of the rail (2). A mechanical unit (10) avoids the frame to be inclined to upstream side or downstream side, when the frame is at a horizontal part or an inclined part or at a transition zone between the horizontal part and the inclined part of the rails (1, 2).</p> |
