Abstract: A method is described for operating a vehicle fitted with a continuously variable transmission (CVT) and having a lever for varying the transmission ratio of the CVT to permit the vehicle operator to vary the vehicle wheel speed. In the invention, the transmission ratio of the CVT is limited to a value dependent upon at least one of the prevailing engine speed and the rate of change of the engine speed.

Abstract: A vehicle includes a continuously variable transmission by means of which torque is transmitted from an engine to drive wheels of the vehicle, a braking system for applying a braking force to the drive wheels and a controller for setting the transmission ratio of the transmission. Additionally, means are provided for applying to the controller a signal indicative of the engine applied torque, and means for supplying to the controller a signal to indicate application of wheel brakes. The controller is operative when the brakes are applied to discontinue setting the transmission ratio in dependence upon the speed of the drive wheels and to set the transmission ratio instead in such a manner as to minimize the absolute value of the engine output torque or the torque transmitted through the transmission or to follow a desired torque setpoint.

Abstract: An apparatus for the parking lock of a vehicle, in particular, of an agricultural tractor. The apparatus comprises a parking lever mechanically linked to a braking lever by a cinematic chain. The braking lever comprises a tooth apt to engage at least a braking element vehicle. The braking lever is provided with a yielding device placed in correspondence to its own hinge. The yielding device is able to ease the engagement of the tooth with a gap comprised between two teeth of a driveline gear in order to guarantee a reliable parking lock of the vehicle.

Abstract: A system and method for controlling the torque transferable by a mechanical drive between an engine and a shaft of a vehicle includes a first actuator which acts on a variable-speed drive, a second actuator which acts on a clutch to determine the degree of engagement/release of the clutch; and a measuring device for measuring the torque to or from the variable-speed drive. The first and second actuators and the measuring device are controlled by an electronic central control unit to protect the variable-speed drive and/or the clutch from mechanical overloading of the mechanical drive.

Abstract: A method is described for operating a vehicle fitted with a continuously variable transmission (CVT) and having a lever for varying the transmission ratio of the CVT to permit the vehicle operator to vary the vehicle wheel speed. In the invention, the transmission ratio of the CVT is limited to a value dependent upon at least one of the prevailing engine speed and the rate of change of the engine speed.

Abstract: A system and method for controlling the torque transferable by a mechanical drive between an engine and a shaft of a vehicle includes a first actuator which acts on a variable-speed drive, a second actuator which acts on a clutch to determine the degree of engagement/release of the clutch; and a measuring device for measuring the torque to or from the variable-speed drive. The first and second actuators and the measuring device are controlled by an electronic central control unit to protect the variable-speed drive and/or the clutch from mechanical overloading of the mechanical drive.

Abstract: An apparatus for the parking lock of a vehicle, in particular, of an agricultural tractor. The apparatus comprises a parking lever mechanically linked to a braking lever by a cinematic chain. The braking lever comprises a tooth apt to engage at least a braking element vehicle. The braking lever is provided with a yielding device placed in correspondence to its own hinge. The yielding device is able to ease the engagement of the tooth with a gap comprised between two teeth of a driveline gear in order to guarantee a reliable parking lock of the vehicle.

Abstract: A vehicle is described having a continuously variable transmission by means of which torque is transmitted from an engine to drive wheels of the vehicle, a braking system for applying a braking force to the drive wheels and a controller for setting the transmission ratio of the transmission in such a manner as to maintain a desired speed of the drive wheels or of the engine. In the invention means are provided for applying to the controller a signal indicative of the engine applied torque, and means for supplying to the controller a signal to indicate application of wheel brakes. The controller is operative when the brakes are applied to discontinue setting the transmission ratio in dependence upon the speed of the drive wheels and to set the transmission ratio instead in such a manner as to minimise the absolute value of the engine output torque or the torque transmitted through the transmission or to follow a desired torque setpoint.