Overload protection: equipped self re-setting overload protector, the hoistmotion is stopped if overloading occurs, but lowering is permitted, making the crane safe.
过载保护装置：当过载发生时，运行下降，不允许上升，便于重物安全落地。
2
The spreader is linked to the crane through the rope, and its motion state is changed complicated in three-dimension with the accelerating and decelerating of trolley, hoist and gantry.
随着起重机大车、小车及起升机构的加速和减速，由钢丝绳连接的吊重的运动状态表现为一个复杂的空间运动。
3
The motion detection is a key technology in the hydraulic hoist control.