Split-seconds device with epicycloidal train for a timepiece

A split-seconds device for a timepiece, in particular for a chronograph watch, the device comprising:

• a split-seconds pinion which carries a fly-back hand and is mounted such as to rotate freely about a rotation arbor of said timepiece;
• a differential having an entry wheel adapted to be kinematically connected to a power source of the timepiece;
• a first exit wheel kinematically connected to the entry wheel by at least one planetary wheel and meshing with the split-seconds pinion;
• a second exit wheel kinematically connected to said entry wheel by said at least one planetary wheel, and a control lever allowing to block either the first exit wheel or the second exit wheel, such that whichever of the first exit wheel and the second exit wheel is released by the control lever is adapted to be driven by said entry wheel when the latter is kinematically connected to the power source of the timepiece, thus allowing to block or respectively release said fly-back hand.