The essential parts of a clock are in a small case and on its outside, there is the dial. Through the center of the extended axis, there is the minute wheel, and on its end there is the minute hand, which moves in one hour once around the dial. At the same axis is still the minute transmission, which is moved by the gear for the display of hours, which rotates once in twelve hours. The minute wheel is rotated by a transmission from one gear, which is set in motion by a spring. It is important that the minute wheel slowed down in its movement. The number of rotations is taking place according to the desired time. Thus, the slowness of the minute wheel by inhibiting the movement is made of a gear. The device, which causes this inhibition is called the balance wheel. The balance wheel works in principle like a pendulum. But instead of a pendulum, a coil spring is used. The coil spring is connected to the metal hoops on its axis. Coiled spring, of course, wants to unfold again. While they were unfurled, rotates with the metal tire. But at some point, the spring has not enough power to a driving force for the metal tire. The metall tire is now swinging back and rolls his coil spring again. At a certain point, the spring can no longer be rolled up and unrolled the coil spring up again. If the metal tire is now swinging back and forth, it raises again and again the anchor and the clock keeps running. If the anchor dissolves or reaches back into gear and stop the gear and then released again, one hears the clock ticking.