Patent ID: 9630493
Date: 2017-04-25
CPC Classifications: B60K,B60W,B60Y,F16H

Claim:
1. A motor vehicle having: prime mover means; at least first and second groups of one or more wheels; control means; and a driveline arranged to connect a torque transmission path from the prime mover means to the first and second groups of one or more wheels such that the first group of one or more wheels and not the second group is coupled to the torque transmission path when the driveline is in a first mode of operation and both the first and second groups of one or more wheels are coupled to the torque transmission path when the driveline is in a second mode of operation, the driveline being arranged to connect the second group to the torque transmission path by means of an auxiliary portion comprising first and second releasable torque transmitting means and a prop shaft, the first releasable torque transmitting means being arranged to connect a first end of the prop shaft to the torque transmission path, the second releasable torque transmitting means being arranged to connect a second end of the prop shaft to the second group of one or more wheels, the control means being arranged to control the auxiliary portion to switch the driveline between the first and second modes of operation such that in the first mode the prop shaft is disconnected from both the torque transmission path and said second group of one or more wheels, wherein, when the driveline is in the second mode, the control means is arranged to operate the vehicle not to transition to the first mode from the second mode unless an at least one vehicle operating parameter has no value corresponding to a condition for the second mode to be assumed during a period of time not less than a disconnect delay period, wherein the timing of the period of time is commenced only when the driveline is in the second mode.