Lifting hoist is a common manual labor-saving lifting tool with braking device. There are many classifications of lifting hoists, which are mainly used for lifting or traction of heavy objects in the construction of power transmission lines, and tightening of steel strands and aluminum strands in overhead construction. In addition, it is also used for equipment anchoring. Lifting hoists include electric hoists, chain hoists, hand hoists and lever hoists. Generally, there are three types of electric hoist, hand chain hoist and lever hoist. The details of the electric hoist are a very big category. The difference between the electric hoist and the chain hoist is mainly the power supply, and the functions realized are basically the same. According to its different models and specifications, it can be divided into: wire rope electric hoist, chain electric hoist, explosion-proof electric hoist, stage electric hoist, metallurgical electric hoist and so on. Lever hoist can be divided into chain type lever hoist and wire rope type lever hoist, which are mainly used for lifting goods and traction of mechanical parts, as well as tightening steel strands and aluminum strands in wire construction. The lifting weight of the hand hoist is generally no more than 3t, and the lifting height is usually 1.5m. A person can directly pull the handle on the ground to operate the lifting of that cargo. The hook can be lowered quickly when there is no load, which can greatly shorten the return time. Chain hoists are divided into round chain hoists and triangular chain hoists according to their appearance. The two types of chain hoists with different shapes can be divided into many types of chain hoists according to their performance and environment. When the chain hoist lifts the weight upwards, pull the manual chain and hand chain wheel clockwise to rotate, and pull the hand zipper bar counterclockwise when descending. The brake seat and the brake chain hoist are separated from the chain hoist. The ratchet is under the action of the pawl At rest, the five-tooth long shaft drives the hoisting sprocket to run in the opposite direction, so as to steadily lower the weight.