| 摘要 |
<p>PURPOSE:To prevent an article and the like from colliding by switching over a frequency to an invertor for a drive motor which is used for travelling of a movable shelf when a foreign object is detected on the way in motion in a shelf installation equipped with movable shelves. CONSTITUTION:A frequency set device 9 is arranged which stores data in advance based on an inertia distance (l) and an inclination of a floor, if any. And a movable shelf 2 is allowed to travel at a certain speed V1 by means of a motor 6. When a foreign object is detected on the way in motion by a foreign object detector 11, a signal is input to the frequency set device 9 permitting device 9 to switch over to a low speed range. This allows the frequency to an invertor 8 to be gradually decreased based on the set point permitting the movable shelf 2 to be decelerated in travelling. This causes the frequency to be decreased to a level which allows the motor 6 to stop at the end of the desired inertia distance (l) permitting the movable shelf 2 to stop at the stated position. This configuration prevents a possible collision due to the settlement of a floor.</p> |
