The running clock , also called watchwinder in English, is a system to artificially recharge a mechanical watch with automatic winding .
These watch movements are equipped with a mass that rotates about an axis, generally located on the bottom of the case. With each movement of the mass, a system of ratchets stores the energy produced in a spring which feeds the movement of the balance, rotating the pinions of the watch. This type of device is useful for watch collectors who want to change every day of the stopwatch without having to restart them every morning, which may seem simple but can prove tedious for complicated models : date with months and years, Phases of the moon … This also reduces the risk of damaging the thread of the screw and the seal of the crown.
Two philosophies clash on the impact of this permanent life on the movements: some prefer to let the watches stop to not use the sprockets, others prefer to keep the mechanics in action to maintain a good oiling of the parts. They generally make between 650 and 900 turns per day (TPD, Turn Per Day ).
Generally constituted of a box of precious wood around an electric motor , there are watch-wheels of all kinds and all prices.