What is a bicycle bell?
The bicycle bell is installed on the handlebar of the bicycle, and its main function is to provide warning to the surrounding vehicles or pedestrians. The bicycle bell is composed of 3 parallel externally meshing spur gears and a simple rocker. There are rocker, bar gear 1, gear 2, and gear 3. When the rocker swings up and down, the gear 1 meshes with the gear 2 externally, driving the gear 2 to rotate, and the gear 2 meshes with the gear 3 externally, so that the gear 3 rotates indirectly by the swing of the rocker.

How bicycle bells work
There are multiple gears in the bell. There is a plastic clip on the top and 3 ring-shaped metals on the top. When the wrench is pressed, the plastic clip rotates very fast due to the gear shifting, and the 3 metal rings fly over due to centrifugal force. At the most extreme, there is a small downward protrusion on the bell lid, which collided with the metal ring and made a sound.
There is a small spring hammer inside the bell. When a person presses the bell, the gear on the handle is transferred to the gear on the cover to make the cover rotate. A protruding part of the cover toggles the spring hammer, and the spring hammer bounces on the cover and emits a crisp bell.