| 摘要 |
<p>PROBLEM TO BE SOLVED: To convey wafer carriage boxes having plural standards and differed form each other in size. SOLUTION: An automatic conveying system stacker crane for conveying boxes 1 having plural standards and differed from each other in size is provided with a truck 32, and a box-holding device 34. The holding device 34 is equipped with a pair of hands 37 which can be symmetrically opened and closed by a linear motor 36, a pair of position sensors 38 for sensing the present positions of both the hands, and a checking device 39 for checking the relationship between the detection signals from both the position sensors and the load on the linear motor 36. When the holding device holds a box, both the hands are symmetrically closed from both sides, and when the relation of both the hands to the box becomes symmetrical, holding operation is automatically completed. Thus, since the box-holding device can handles boxes of different sizes, a storehouse, an automatic conveying system can realize a mixed flow of boxes of various standard sizes.</p> |
