Overhead trolley is the work trolley of used to withstand the object, supporting hanging chain, and walking along the i-steel rail by chain. Overhead trolley have hanger, and the hanger can hang slings. The main purpose of the overhead trolley is support the weight of the objects, chain and slings. In the vertical bending section on chain tension force, also ensure the chain running along the track. In the conveyor line, the distance of 2 overhead trolley may not too far, usually maybe 6 chain links. If the distance too far, In order to ensure the best state, we suggest to add a light in the middle of 2 overhead trolley.