| 摘要 |
<p>PURPOSE:To ensure an automatic stop for a truck so that the goods on the truck may be an range of allowable error, by providing two optical position detectors on the railroad. CONSTITUTION:The optical position detectors A and B are provided at the upper and lower limit positions of the range of allowable error to the desired stop position of the goods 3 on the truck 2. Then the truck 2 moves left on the railroad 1, and the front edge of the goods 3 cuts the light of the detectors A. Thus the counter 11 stops the truck 2 after counting the number of pulses of the pulse generator 9 up to a prescribed value. In this instant, if the rear edge of the goods 3 cuts the both lights of detectors A and B, the truck 2 is moved forward slightly. While the truck is moved backward slightly when the rear edge does not cut either lights. Then the truck is stopped at such position where the light of the detector B is cut off by the truck and the light of the detector B is not cut off, respectively. Thus the goods can be stopped automatically within a range of allowable error.</p> |
