Self-winding mechanical watch is the best choice for people who run an active lifestyle. Most sports models of mechanical watches are equipped with automatic winding. The same can be told about watches for travellers and divers, for all who are totally immersed in a favorite activity and involved in the process.
Automatic winding is the most common improvement of the movement. It not only eliminates the need of winding the watch manually, but also positively affects the accuracy of the watch due to the fact that the spring is always wound.
For the first time the movement with automatic winding appeared in the XVIII century and mechanical self-winding watch was released in 1931. But mass production of watches with this feature began only 20 years later, in the 50s of the XX century. Due to its convenience and usefulness mechanics with self-winding was firmly established in manufacturing of watches and became the new standard for many watch brands.
The automatic winding of watches is a small cam (watchmakers call it the rotor or sector), the device which rotates around its axis at the slightest vibration. The rotation takes place due to the shifted center of gravity. For this purpose, the winding mechanism consists of two parts: a thin and light plate and heavy made of an alloy of tungsten or gold cover on it. The cam is connected with a spring by a friction clutch, the coupling used for transmission of rotational motion. Hand movement makes the cam rotating and thereby winding the spring. The winding goes on even during the walk, so that constant wearing of the watch keeps it working. The clutch also protects the spring from overwind: when fully wound, it slips over the spring, not bringing it into action.
Mechanics with automatic winding is thicker and heavier than calibers with manual winding, and this affects the appearance of the watch.
Mechanics with automatic winding is almost useless for sedentary people (e.g. the elderly) and those who don’t wear watches regularly, but only occasionally. But it is always possible to wind automatic watch manually.