Abstract: A device for automatic adjustment of the frequency of activation of a motor vehicle windscreen wiper driven by a motor is described. The main characteristic of the device lies in the fact that it comprises circuit means which control the frequency of activation as a function of the quantity of water present on the surface which is wiped by the windscreen wiper.

Abstract: A mechanism for providing differential control of the opening of the throttle valve which controls the amount of air introduced into the induction manifold of an internal combustion engine. The angle of opening of the throttle valve changes with a predetermined law of variation with respect to the displacement of a member controlled directly by the throttle pedal; this member has cam faces formed thereon for successive engagement by different rollers spaced along a transmission member the angular displacement of which is directly related to the angular displacement of the throttle valve. Transmission of movement from the transmission member is by means of meshing toothed sectors providing a fixed ratio, or by way of direct connection to the butterfly spindle.