Abstract: The fan comprises a volute housing (10) in which is disposed a ventilation wheel (11) connected to a driving motor (12). The wheel has a series of vanes (13) extending in a direction roughly parallel to the axis of rotation (X--X) of the wheel from a bowl (14) connecting the vanes to the driving motor to an edge portion (15) of an air intake (16) defining with the bowl a space for a fluid stream. The confronting surfaces of the bowl and the edge portion of the air intake, at least to the inner edges of the vanes, are generated by rotation of parallel sections of curves about the axis of rotation (X--X).

Abstract: This device for transmitting data, coming from a plurality of control elements (8 to 11) mounted on a steering wheel of a motor vehicle, to a system recognizing the data and also mounted on the vehicle, comprises light sources (12 to 15) mounted on the steering wheel and respectively connected to the control elements. The light sources are disposed in such manner as to cooperate with annular means (16 to 19) coaxial with the steering wheel for transmitting light to photosensitive detectors (30 to 33) mounted on the vehicle and adapted to actuate loads corresponding to the actuated control elements, irrespective of the position of the light sources relative to the photosensitive detectors.