Swiss Watch Factory tell you There are two types of mechanical wristwatches: card-degree hairspring balance wheel and free sprung-balance. Which is better?
In general, Watches Manufacturers have two adjustment structures that can be used to change the travel time accuracy of the watch: one is a card-degree hairspring structure, which adjusts the effective length of the hairspring by adjusting the speed of the spring to achieve the purpose of changing the vibration period;
The other is a free sprung balance. This structure is to change the vibration period by adjusting the position of the screw on the balance wheel itself or adjusting the position of the placed rotatable weight. the goal of.
However, there are defects in the card degree mechanical watch: when the watch needs to be adjusted, in order to ensure that the hairspring and the clip are not caught when the full needle is dialed, the shape of the hairspring within the range of the clip should be oscillated. The axis of the shaft is centered on the arc, and there must be a certain gap between the spring and the clip.
When the balance spring system works, due to the root cause of the non-linearity of the spring torque due to the fast and slow needles, when the watch is in different positions, the position of the game in the fast and slow needle clips will change due to the gap, so that the actual working length of the hairspring A change occurs, resulting in a bit difference.
The feature of the free sprung balance structure is that the fast and slow needles are eliminated, and the balance wheel is designed to adjust its moment of inertia, that is, to change the radius of the balance wheel.
There are generally two basic structures:
One is to provide screws or nuts on the outer or inner edge of the balance wheel, and change the radius of rotation of the balance wheel by changing their position away from the center of the balance wheel;
The other is to set a rotatable weight on the plane of the balance near the outer edge. Generally, the weight is semi-circular. By rotating the weight, especially the non-circularity of the weight will produce an eccentric effect. , thereby changing the radius of rotation of the balance.
The final result of these two structures is to change the vibration period by changing the radius of rotation of the balance to achieve the purpose of adjusting the speed of the mechanical watch.
Although the free sprung balance structure adjustment method is more difficult than the card. However, its advantage is that the card structure can not be achieved, so many high-end mechanical watches made by Luxury Watches Manufacturer use this structure to adjust the speed.