US 5,964,680 A · Power train for a motor vehicle

Abstract

An automated clutch between the engine and the variable-speed transmission in the power train of a motor vehicle is operated by a control unit which receives signals from several circuits and/or sensors via one or more conductors. The control unit shifts from a normal operating mode to an emergency mode when one or more sensors and/or circuits and/or conductors are defective. When in emergency mode, the control unit disengages the clutch when the driver starts the engine while the vehicle brake or the parking brake is applied. This ensures that the engine can drive the vehicle as soon as the transmission is shifted into a forward gear or into reverse gear and the application of the brake or brakes is terminated because the control unit is then again free to engage the clutch. Furthermore, such mode of operation enables the driver to shift the transmission into or from a selected gear in response to the application of a relatively small force to the gear shifting lever.

Claims28

Dependent claims

For use in a motor vehicle, a power train comprising a prime mover;

starting means actuatable to start said prime mover;
a variable-speed transmission;
an engageable and disengageable automated torque transmission system;
at least one brake operable to oppose a movement of the vehicle;
and means for operating said system to select the magnitude of torque being transmissible by said system, said operating means comprising a signal receiving, processing and transmitting control unit, means for transmitting signals to said control unit, said signal transmitting means having operative and inoperative conditions, and actuator means arranged to operate said system in response to signals from said control unit, said control unit being effective to operate in a standard mode in the operative condition and in an emergency mode in the inoperative condition of said signal transmitting means, said control unit being operative to disengage said system by way of said actuator means when said starting means is actuated simultaneously with the operation of said at least one brake while said control unit operates in said emergency mode.

2 more elements

A method of operating a power train in a motor vehicle which is provided with at least one brake and wherein the power train comprises a prime mover, means for operating the prime mover, a variable-speed transmission, an engageable and disengageable automated torque transmission system cooperating with at least one of the prime mover and the transmission, and means for operating the torque transmission system to select the magnitude of the torque being transmittable by the system, the system operating means being provided with a signal receiving, processing and transmitting control unit, an actuator arranged to operate the torque transmission system in response to signals from the control unit, and an arrangement which transmits signals to the control unit and has operative and inoperative conditions, comprising the steps of:

operating the control unit in a standard mode in the operative condition of the signal transmitting arrangement;
and
operating the control unit in an emergency mode in the inoperative condition of the signal transmitting arrangement, including disengaging the torque transmission system by way of the actuator when the operating means for the prime mover is actuated and the at least one brake is applied.

Dependencies are inferred from the claim text.

Power train for a motor vehicle

Life of this patent

Power train for a motor vehicle

Life of this patent

Abstract

Claims28