Abstract: A tachometric device is provided with a D.C. electric motor a shaft of which drives a pair of permanent magnets to rotate. A first permanent magnet controls a speed indicator unit; a second permanent magnet is rotatably mounted within a winding the terminals of which are connected to a negative feed back circuit for controlling the speed of the motor.

Abstract: A speed indicator device for vehicles is described, of the type in which the speed indication is given over a scale by an index fitted to an oscillating element drawn for example, by a permanent magnet carried into rotation by the shaft of an electric motor. The device comprises a bush on one side fixed to the magnet and on the other fixed, by a spring, to the shaft of the electric motor.

Abstract: A vehicle fuel level sensor comprising a hollow cylindrical body housing a sliding float, the position of which is determined by the fuel level in the fuel tank. The sensor also comprises a filter surrounding as portion of the side wall of the cylindrical body, close to the bottom wall of the same, so as to define, with the side wall, a first chamber; and a plate for supporting the filter and connected to the bottom wall of the hollow cylindrical body so as to define, with the bottom wall, a second chamber communicating directly with the first chamber and, via a through hole in the bottom wall, with the inside of the hollow cylindrical body.

Abstract: A tachometric generator comprises an input shaft which can be connected to a drive take-off from the vehicle, a main shaft connected to this input shaft by means of a ball joint resilient coupling torsionally coupled to an output shaft which can be connected to an external mechanical transmission. The speed of rotation of these shafts is detected by a magneto-electric sensor facing a magnetic disc fitted onto the output shaft.

Abstract: The device is of the type comprising a magnet carried by a float and a magnetically actuable electric contact carried by a support element which also performs the function of guarding the float. The most important characteristic of the device is that of providing positioning means which maintain the float constantly centered with respect to the support element during excursions of this latter caused by the hydrostatic thrust exerted by the liquid.