A motor-driven carriage (100) for opening/closing a curtain, includes a housing (110) that is provided with two members (124, 126) for suspending the housing from a rail (50), wherein a friction wheel (112), which is driven by an electric motor and which is to contact at least one rolling surface (56, 57) of the rail, is rotatably mounted inside the housing. The carriage (100) also includes a cradle (150) provided with two other members (155, 156) for suspending the cradle from the rail (50), which are separate from the members (124, 126) for suspending the housing (110), as well as elements (153, 154) for coupling to the curtain. The cradle is mounted onto the housing (110) and is driven by the housing when the latter moves along the rail, the housing (110) and the cradle (150) optionally being capable of relative movement there between.