Patent ID: 6237712
Filing Date: 2001-05-29
Classification: F16H

Abstract:
An electric circuit for an automotive vehicle that comprises an engine for powering the vehicle, a drivetrain through which the engine can deliver torque to road-engaging wheels for propelling the vehicle, and brakes which can be selectively applied to brake the vehicle, the drivetrain comprising a multi-speed axle that contains the wheels, an axle-shifting mechanism, including an electric actuator, for shifting the axle between different speed ranges, and a transmission that operatively couples the engine to the axle and can be selectively shifted to a neutral gear incapable of transmitting engine torque to the axle and to a drive gear capable of transmitting engine torque to the axle, the electric circuit comprising:an electric circuit device for distinguishing between actuation and non-actuation of the brakes;an electric circuit device for distinguishing between the transmission being in neutral gear and the transmission being in drive gear; andelectric circuitry operatively coupling the two electric circuit devices with the actuator for allowing the actuator to change the speed range of the axle upon concurrence of the brakes being actuated and the transmission being in neutral gear, and for disallowing the actuator to change the speed range of the axle if either the brakes are not being actuated or the transmission is in drive gear.