Abstract: A load sensing hydraulic system includes two pumps, at least one hydraulic fluid consumer, and a pressure balance circuit. In the case of no demand from the consumer, hydraulic fluid flows from the pumps through the pressure balance circuit and to tank. In the case of demand from the consumer for hydraulic fluid at a flow rate less than or equal to the flow rate provided by the first pump, hydraulic fluid from the first pump flows to the consumer, and hydraulic fluid from the second pump flows to the tank. In the case of a demand from the consumer for hydraulic fluid at a flow rate greater than the capacity of the first pump, hydraulic fluid from both pumps flow to the consumer.

Abstract: A power take off drive train for an agricultural tractor includes at least one input shaft and an output shaft that are rotatably mounted in a transmission casing, wherein the gear train provides for the output shaft to be rotated at one of three selected speeds, one of the at least one input shafts mounting first and second input gear wheels and a selector, the gear wheels being free to rotate on the shaft, and wherein the selector is mounted on the shaft for rotation therewith, and to slide axially along the shaft to engage with one of the first and second gear wheels transmitting torque thereto, and wherein the output shaft mounts first and second output gear wheels fixed for rotation therewith, the first and second output gear wheels being in driving engagement with the first and second input gear wheels respectively, and wherein the drive train further comprises a third output gear wheel that engages with a third input gear mounted on an input shaft mounted in the transmission casing, wherein drive to th

Abstract: A method for controlling an internal combustion engine provided on a vehicle and cooperating with the throttle hand lever and an accelerator pedal, whereby the amount of fuel is predetermined. The amount of fuel is predetermined by respective positions of the accelerator pedal and throttle hand lever and is corrected on the basis of a position of the vehicle brake pedal.

Abstract: A control system for a synchromesh unit, particularly suitable for controlling a synchromesh in a forward/reverse pre-select gear change system. The system is purely hydraulic, incorporating a double acting hydraulic cylinder (1) for moving the synchromesh. The hydraulic circuit controlling the hydraulic cylinder (1) includes restrictions (R.sub.1), (R.sub.2A), (R.sub.2B) and an accumulator (10), which vary the force applied by the hydraulic cylinder (1). The variation of the force applied by the hydraulic cylinder (1) includes a gradual, progressive increase of force whilst the synchromesh is matching its speed to the gear to be engaged, and subsequently allowing the synchromesh mechanism to move rapidly once its speed is matched with the gear to be engaged, to quickly move the teeth of the synchromesh and the gear to be engaged together. The force applied by the hydraulic cylinder is then increased again to a maximum once the synchromesh is fully engaged.

Abstract: A device for automizing a vehicle clutch having at least one single-action hydraulic jack includes two solenoid valves or an equivalent assembly, two pulse sensors for respectively detecting the speed of the wheels and the engine speed of the vehicle, an actuating contact and an electronic cirucit connected to the solenoid valves, the sensor and the contact. The electronic circuit controls declutching and clutching to provide gradual controlled engaging of the clutch according to data relating to the engine speed and vehicle acceleration.