The rescue tripod is a simple mechanical device made by combining three supports to ensure stability. However, although the sparrow is small and has all its organs, each component plays a very important role.

On the upper part of the rescue tripod frame, there is a small component - a sling and pulley, which is located below the top cover and is relatively hidden and not easy to detect.

This pulley is a movable pulley that can continuously rotate around the bearing or move with heavy objects. To prevent the rope from slipping, grooves have been added on its wheel edge. During the lifting operation using a tripod, the operator needs to hang the heavy object on the hook and continuously shake the winch on the tripod. The pulley and sling can continuously transmit thrust, gradually lifting the heavy object to a high place.

In addition, the slings and pulleys on the rescue tripod can not only change the method of force, but also achieve a labor-saving effect, which is convenient and convenient, similar to the labor-saving principle of a lever, making a huge contribution to human deep well rescue work.