Device for actuating a wiper system, in particular for a motor vehicle windscreen, and wiper system including such a device

The device has a drive hub (200) for driving an arm around a pivot axis (7) and an elastic return unit (202) arranged to apply the arm in a direction of a pane by providing support to the hub. The elastic unit includes a spring (204) with a corrugated wire. The spring is positioned on the hub so as to exert axial effort directed according to the axis. The hub includes an articulation axis (210) of the arm directed transversely to the pivot axis. The spring includes coils provided with undulations defining peaks, where the peaks are in contact with each other.