A drive system for rotating a winding member of a windable closure screen apron about a central axis (X), the drive system comprising: - an actuator driving an output shaft , - a main shaft driven by the output shaft , - at least one torsion spring , - a disengageable device , characterised in that : - the drive system comprises a rotary element that is rotatable and translationally fixed relative to the main shaft , and is rotationally fixed to the winding member , - the torsion spring is fixed at one end to the main shaft and at the other end to the rotating element , - the disengageable device , in an engaged configuration, makes the main shaft and the rotary member rotationally integral, and in a disengaged configuration, disengages the main shaft and the rotary member rotationally integral, whereas in the disengaged configuration the torsion spring is adapted to be pre-stressed by relative rotation between the main shaft and the rotary member , and the pre-stressed torsion spring drives the rotary member in rotation about the central axis (X) so that the curtain is driven towards a rolled-up configuration, - the drive system also comprises a threaded rod rotationally fixed to the main shaft and a slider screwed onto the threaded rod and rotationally fixed with respect to winding member in such a way that the slider is translationally movable along the central axis (X) of the system between a first position, in which the spring is not prestressed and the actuator is free to pre-stress the spring by free rotation between the main shaft and the rotary element , and a second position, in which the spring is pretensioned and the slider is in abutment against an element integral with the main shaft so that the actuator is automatically stopped. - an actuator driving an output shaft , - a main shaft driven by the output shaft , - at least one torsion spring , - a disengageable device , - the drive system comprises a rotary element that is rotatable and translationally fixed relative to the main shaft , and is rotationally fixed to the winding member , - the torsion spring is fixed at one end to the main shaft and at the other end to the rotating element , - the disengageable device , in an engaged configuration, makes the main shaft and the rotary member rotationally integral, and in a disengaged configuration, disengages the main shaft and the rotary member rotationally integral, whereas in the disengaged configuration the torsion spring is adapted to be pre-stressed by relative rotation between the main shaft and the rotary member , and the pre-stressed torsion spring drives the rotary member in rotation about the central axis (X) so that the curtain is driven towards a rolled-up configuration, - the drive system also comprises a threaded rod rotationally fixed to the main shaft and a slider screwed onto the threaded rod and rotationally fixed with respect to winding member in such a way that the slider is translationally movable along the central axis (X) of the system between a first position, in which the spring is not prestressed and the actuator is free to pre-stress the spring by free rotation between the main shaft and the rotary element , and a second position, in which the spring is pretensioned and the slider is in abutment against an element integral with the main shaft so that the actuator is automatically stopped. <EOS>