The timepiece was invented around the beginning of the 16th century. At first, gravity was used as the source of power. This kind of timepiece could only be placed in a fixed place, such as a tall building or a large wall hanging. A clock is a heavy hammer made of iron tied with a chain and rotated around a wheel. Later, it was invented to use the elastic force of a spring to make it run, which is the spring of today's clocks. This kind of timepiece has been greatly reduced in size. It is as big as an egg and can be carried in a pocket. This is the Nuremberg Egg invented by a locksmith in Nuremberg, Germany. The parts of this watch are all made by hand, so it is very expensive. The work is time consuming, and every watch made is different. It was not until the 19th century that machine manufacturing gradually developed and quality could be controlled. Until now, the names of watch structures are extremely inconsistent. Even within the same region, there are many different names or translations. Moreover, countries around the world lack unified regulations on watch parts. Therefore, the Swiss ETA movement manufacturer first used numbers to represent watches so that watch manufacturers can be correct when purchasing parts. However, although the movement names of brands from various countries are the same, there are still differences in structure and code names. The operation of the clock is based on the principle of leverage, which is repeated back and forth like a swing. The most basic operation sequence is from the spring → center wheel → third wheel → fourth wheel → escape wheel → horse → balance wheel, and then the balance wheel. A simple harmonic motion in which the reaction force of the wheel bounces the horse back to its original position. The spring barrel is the force caused by the elastic force generated by the curling of the steel rod. Generally speaking, the barrel, also called Barrel, is composed of a Mainspring, a Barrel Drum and a Barrel Cover, and uses a square hole gear (Ratchet). Wheel) is transmitted to other gears such as the center wheel. It is the most important basic structure for the operation of the clock. Just like the human stomach, it converts the food eaten into energy. Because this simple structure is convenient and easy to use, it has changed little from ancient times to the present. Not big. When you hear the "ticking" sound of the watch like a metronome constantly swinging, the second hand on the dial also rotates with the rhythm, making us immediately feel the continuous passing of time. This rhythmic sound is caused by the force reaction of the balance wheel to the lever. The balance wheel system is made of alloy and uses a hairspring to cause a reaction force to push the impulse jewel pin back to the lever. A perfect balance wheel usually swings from 225 to 270 degrees. Keep swinging, making time endless. The main structure of a clock, in addition to the spring and balance wheel mentioned earlier, the main gear train in the middle is also the main part that makes time move. They are like human blood constantly receiving the power transmitted from the spring box. This main wheel system includes: (1) the center wheel, also called the Center Wheel or 2nd Wheel; (2) the third wheel, also called the 3rd Wheel; (3) the fourth wheel, Also known as the 4th Wheel; (4) Escape Wheel, also known as the Escape Wheel. These gears are respectively responsible for transmitting hours, minutes, seconds and isochronous rhythms. All power begins when the mainspring is tightened and sends power to the center wheel, third wheel, fourth wheel, escape wheel, catch, and then to the balance wheel, and then the balance wheel reacts to the horse to restore its previous position, and so on Once this happens, the entire operation process can start over again. On weekdays, we see the hour, minute and second hand displays on watches. How are they distributed through gears? When the spring provides power to the center wheel, the center wheel will rotate at a speed of one revolution of 60 minutes. When it reaches the third wheel, it will start to change speed. When it moves to the fourth wheel, it will rotate at a speed of one revolution of 60 seconds. turn around. Therefore, the display of the minute hand is generated by the axis of the center wheel, the display of the second hand is generated by the axis of the fourth wheel, and the display of the hour hand is generated by the hour wheel located on the upper plate connected to the minute hand wheel. of.

Most people will find that the small second hand of some watches will be at 6 o'clock or 9 o'clock, which is determined according to the position of the fourth wheel. In addition, the design of the large second hand is to install a transmission gear train on the fourth wheel, so that the position of the second hand can be changed.