This balance wheel was also invented by the British. The outer ring of the balance wheel is brass, and the inner ring is steel. The two metals are tightly combined by screws. There are more than a dozen screws on the side of the balance wheel, not only for fixing metal, but also for adjusting the position of the balance wheel. Such a design cleverly compensates for the change in rigidity of the balance spring caused by temperature changes, and the change in rigidity will bring replica watches about not small travel time errors. When the temperature rises, the balance spring becomes longer, and the balance wheel shrinks inward because the expansion coefficient of copper is greater than that of steel. Conversely, as the temperature decreases, the balance spring becomes shorter and the balance wheel expands outward. This design continued until the end of the invention of Invar alloy.
Such a sophisticated design is usually seen on the "navigation chronometer", but the astronomical clock is matched with a cylindrical hairspring, commonly known as a "barrel hairspring". It is very difficult to make a barrel-shaped hairspring, but the benefits of this kind of hairspring are also obvious-it can greatly reduce the position difference caused by the diastolic difference of the hairspring. But this kind of hairspring is usually not used on portable clocks, because it takes up too much volume, a well-dressed gentleman, his pocket watch pocket is a big bulge, which is really not elegant.
The advantage of this hairspring is that it solves two problems: the hairspring is concentric and small in size. The Shangrao part of the most primitive Breguet hairspring has a straight line. Later there were different variants, that is, the straight line was cancelled, but the function is still complete. As for the story of Mr. Breguet who invented the tourbillon in order to completely solve the phenomenon of position difference, it will not be explained here.
But it is worth mentioning that it is not only Mr. Breguet who has solved the problem of concentric replica watches uk hairspring that has plagued everyone for many years. The LOSSIER hairspring also has the same effect. Although his focus is not on solving the concentric problem, according to the only available information, such an invention mainly solves the problem that the Breguet hairspring is easy to be shaken and hang up.