CPC B66D 1/485 (2013.01) [B66D 3/26 (2013.01)] | 9 Claims |
1. An apparatus which comprises:
means for measuring a signal which describes a force caused by the load to the chain;
means for performing high-pass filtering to the signal and for determining a maximum and minimum force affecting the chain of the chain hoist during a vibration period, and determining the start of resonance based on the maximum and the minimum;
means for detecting the start of resonance when a load is moved by a chain hoist;
means for determining a new speed for the rotation of a chain wheel of the chain hoist such that resonance is avoided, wherein the new speed is determined by adding a correction term to a speed instruction, and the speed instruction determines a speed on which the chain wheel is rotated by means of a motor; and
means for controlling the chain hoist to use the new speed.
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