The spring deforms under the action of external force, and the spring can recover after the external force is removed. Many tools and equipment use the spring to reset. For example, the hinges of many building doors are equipped with reset springs, and the doors will reset automatically after people enter and leave. People also make use of this function to make automatic umbrella, automatic pencil and other supplies, very convenient. In addition, all kinds of buttons and buttons also need a return spring.
Mechanical clocks and clocks, spring toys are driven by tightening the spring. When the spring is tightened, the spring will produce bending deformation and store a certain elastic potential energy. After release, the elastic potential energy is converted into kinetic energy, which is driven by the transmission device. Toy guns and starting guns and military guns are also used to work with one of the properties of springs.