Abstract: A mechanical gearbox for motor vehicles presenting: a first shaft; a second shaft; a plurality of gear pairs, each of which mechanically couples the first shaft to the second shaft, defines a corresponding speed and comprises a first gear mounted on the first shaft and a second gear which is mounted on the second shaft and permanently meshes with the first gear; a plurality of synchronizers, each of which is mounted coaxially to a shaft between two gears of two gear pairs and is adapted to be actuated to alternatively engage the two gears to the shaft; and an actuation system for displacing each synchronizer alternatively in the two senses along the respective shaft and comprising a plurality of forks, each of which envelops a corresponding synchronizer; the gear pair of two consecutive speeds are arranged so as to be engaged by two different synchronizers; and the actuation system independently actuates the synchronizers.

Abstract: Pneumatic system for controlling the valves of an internal combustion engine; the pneumatic system is provided with: a pneumatic accumulator containing pressurized air; a pneumatic manifold; a control device to connect the pneumatic manifold alternatively to the pneumatic accumulator with the internal combustion engine in the high rpm range and to the atmosphere with the internal combustion engine in the low rpm range; a plurality of pneumatic springs, each of which has a variable volume actuating chamber and a piston mounted slidingly inside the actuating chamber; a plurality of connecting conduits, each of which connects the actuating chamber of a respective pneumatic spring to the pneumatic manifold; and a plurality of calibrated cross-sectional portions, each of which has a reduced cross-sectional area and is arranged along a respective connecting conduit.

Abstract: Internal combustion engine provided with a plurality of cylinders divided into a first group and a second group; a control unit for deactivating all the cylinders of the second group; a first exhaust conduit and a second exhaust conduit, which are reciprocally connected at an intersection and which are respectively connected to cylinders of the first group and to cylinders of the second group; a catalyzer, which is arranged along the first exhaust conduit upstream of the intersection and is provided with first sensors for detecting the exhaust gases; and a second catalyzer, which is arranged downstream of the intersection and is provided with second sensors for detecting the exhaust gas composition.

Abstract: Pneumatic system for controlling the valves, of an internal combustion engine; the pneumatic system is provided with: a pneumatic accumulator containing pressurized air; a pneumatic manifold; a control device to connect the pneumatic manifold alternatively to the pneumatic accumulator with the internal combustion engine in the high rpm range and to the atmosphere with the internal combustion engine in the low rpm range; a plurality of pneumatic springs, each of which has a variable volume actuating chamber and a piston mounted slidingly inside the actuating chamber; a plurality of connecting conduits, each of which connects the actuating chamber of a respective pneumatic spring to the pneumatic manifold; and a plurality of calibrated cross-sectional portions, each of which has a reduced cross-sectional area and is arranged along a respective connecting conduit.

Abstract: A mechanical gearbox for motor vehicles presenting: a first shaft; a second shaft; a plurality of gear pairs, each of which mechanically couples the first shaft to the second shaft, defines a corresponding speed and comprises a first gear mounted on the first shaft and a second gear which is mounted on the second shaft and permanently meshes with the first gear; a plurality of synchronizers, each of which is mounted coaxially to a shaft between two gears of two gear pairs and is adapted to be actuated to alternatively engage the two gears to the shaft; and an actuation system for displacing each synchronizer alternatively in the two senses along the respective shaft and comprising a plurality of forks, each of which envelops a corresponding synchronizer; the gear pair of two consecutive speeds are arranged so as to be engaged by two different synchronizers; and the actuation system independently actuates the synchronizers.

Abstract: Internal combustion engine provided with a plurality of cylinders divided into a first group and a second group; a control unit for deactivating all the cylinders of the second group; a first exhaust conduit and a second exhaust conduit, which are reciprocally connected at an intersection and which are respectively connected to cylinders of the first group and to cylinders of the second group; a catalyzer, which is arranged along the first exhaust conduit upstream of the intersection and is provided with first sensors for detecting the exhaust gases; and a second catalyzer, which is arranged downstream of the intersection and is provided with second sensors for detecting the exhaust gas composition.