| 摘要 |
<p>A grading plant with self-cleaning screen for lump materials, the screen (3) being pivotally mounted to a carriage (2) displaceable on horizontal beams (1). The screen has wheels (5) guided in tracks in the beams. Each track has a horizontal portion (11) and a curved downwards directed portion (12). The screen is in a position for discharging when the wheels (5) are in the lower most part of the downwards directed portion. The motion of the screen is exerted by a moving device consisting of a wire arrangement (7) for the backwards directed movement and a return spring (20) for the return motion, or a double-acting hydraulic cylinder (18) moving the carriage in both directions. </p> |
