HOROLOGICAL MOVEMENT COMPRISING A CHRONOGRAPH MECHANISM

A horological movement including a running train driven by a first energy source; a regulating member for regulating the running train; a chronograph mechanism including a chronograph train driven by a second energy source; a coupling configured to couple the chronograph train, on demand, to the regulating member to regulate the chronograph train using the regulating member; a chronograph start/stop control device cooperating with the coupling; wherein the coupling is a differential coupling including a first input wheel driven by the running train and having a rotational speed that is regulated by the regulating member; an output wheel meshed with the chronograph train; a second idle input wheel cooperating directly or indirectly with the chronograph start/stop control device; the coupling including a drive assembly configured to rotate the output wheel at the rotational speed regulated by the regulating member.