Repeater with disengageable transmission mobile

A repeater mechanism for a timepiece with a striking mechanism, which comprises:

• an hours snail;
• an hours piece provided with a toothed sector and carrying an hours follower, the hours piece being mounted to rotate between a fixed rest position, wherein the hours follower is angularly spaced from the hours snail, and a reading position wherein the hours follower comes into contact with the hours snail;
• a device for regulating the angular speed of the hours piece, which comprises a rotor and a system for braking the rotor;
• a transmission gear train between the hours piece and the rotor;
• wherein the transmission gear train comprises a disengageable primary mobile able to adopt two configurations:
• a) an engaged configuration wherein the primary mobile couples the hours piece and the rotor while the hours piece is moved from its reading position to its rest position;
• b) a disengaged configuration wherein the primary mobile decouples the rotor and the hours piece as soon as the latter is stopped in the rest position, and
• wherein the primary mobile comprises:
• a primary input wheel, mounted to rotate about a primary axis and connected to the hours piece;
• a primary output wheel rotatable relative to the primary input wheel and connected to the rotor;
• and
• a unidirectional primary epicyclic gear train between the primary input wheel and the primary output wheel.