Forgotten landmarks in watchmaking evolution
-There have been many technological leaps forward in watchmaking, but with time the novelty of these jumps soon dampens and are forgotten as they become the new norms and standards.-
Unbreakable Mainsprings
A mainspring is the spring found in the barrel that powers a mechanical watch. Every mechanical watch requires a power source to drive the wheels that lead to the regulatory organ, that is in 99.9% of watch movements an oscillating balance wheel.
Early mainsprings were made from carbon steel and would in most cases, fatigue and break, even when they were protected by various mechanisms (stop-works) that would prevent them from being fully wound or unwound. The development of new alloys dramatically reduced the breakage issue, as well as assured improved consistency in the transmission of force as the watch runs down.
The power source is a mainspring, wound either manually by hand through a winding crown, or by an automatic winding system incorporated into the watch movement.
Although there are always exceptions to every rule in horology, there exist two fundamental types of mainspring. Those that when fully wound are blocked from turning, made for manually wound movements, and automatic mainsprings.
Automatic mainsprings have a longer bridal fixed at their end that push against the inside of the last turn of the spring, approximately 20% thicker than the rest of the spring. This long bridal allows the mainspring to slide on the inside of the barrel (where the mainspring lives) once the spring is fully wound. This allows the automatic mechanism to continue to turn, continuing to wind the fully wound spring without causing any damage.