Patent ID: 6251045
Filing Date: 2001-06-26
Classification: B60K,B60W,F16H,Y10T

Abstract:
A method of synchronizing low to high shifts in a transfer case used in an automotive vehicle, said method comprising:initiating an actuator to move a clutch from engagement with a gear set to a predetermined neutral position and measuring the speed of the actuator;determining the additional time until the clutch will reach a predetermined synchronization point using the speed of the actuator and the remaining rotational distance through which the actuator must move for the clutch to reach the predetermined synchronization point;moving the clutch until it has reached the predetermined synchronization point, stopping the actuator when the clutch has reached the predetermined synchronization point for no longer than a predetermined time;sensing and comparing the rotational speed of the transfer case input and output shafts; andcompleting the shift from low to high by moving the clutch to provide direct torque translation between the input and output shafts when the difference in the rotational speeds of the input and output shafts is less than a predetermined value.