A.Lange & Sohne patented a stop-second mechanism for escapement in 2005.
The Tourbillon-stop enables precise time adjustment every second. It is activated by pulling the crown. Two spring arms profiled in "V" at the ends embrace the balance wheel pressing on it and stop the tourbillon device. Both ends of the springs are bent outwards to prevent accidental catches during braking and stopping the balancing wheel.
The patented device with a specially shaped locking spring allows to stop the tourbillon at any time, regardless of the position of balance wheel and the tourbillon cage’s.
The invention has another advantage: since the balance is stopped directly, the energy from the spring is accumulated so that the balance can automatically restart oscillation as soon as the crown is placed in original position.
Application: Tomasz Jakubas
Other records: Timeline of Watchmaking Innovations