This invention relates to a system for ensuring uninterrupted running of the engine-driven air conditioner of a STOP START featured motor vehicle , even after the engine has stopped.
When the vehicle is stopped for traffic signal, the engine gets stopped with pre-determined time. When the engine is stopped, the AC compressor also stops and hence, maintaining climatic control is lost as the compressor was getting a drive from the engine.
In current motor vehicles, the "stop-start" feature is incorporated for saving fuel and reducing emission of polluting exhaust gases. The global trend and legislation norm enforce the need for stop start systems in the vehicle as an inevitable technology.
When the engine of a motor vehicle, with its air conditioner ON, is temporarily shut OFF by such feature in a traffic jam or, say, at a traffic signal, to save fuel and reduce emission of exhaust gases, this invention comes into operation, automatically and immediately on the engine of the vehicle shutting OFF, to continue to run the air conditioner, without interruption, thus avoiding any discomfort to the passengers.

On the engine being re-started by the driver normal operation is restored, and the engine once again takes over the drive to the air conditioner.
The object of this invention is to propose a system for automatically ensuring uninterrupted running of the engine-driven air conditioner of a motor vehicle, even after the engine has stopped.
According to this invention, the system for ensuring uninterrupted running of the engine-driven air conditioner of a motor vehicle, even after the engine has stopped, comprises an air conditioner, the compressor of which is coupled to the engine by a first drive; an electric motor coupled in tandem to the compressor by the first drive through a second drive constituted by a unidirectional clutch, the input power to the said motor being derived from the battery of the vehicle; an electronic control unit (ECU) for activating the motor only when the said unit senses the engine to be OFF and the compressor switch to be ON, the said motor, on activation, driving the compressor, uninterruptedly, through the said clutch, unless the engine is turned ON to resume driving the compressor through the first drive; the said control unit, on sensing the engine to have been turned ON, simultaneously

de-activating the motor, while the said clutch disables the de¬activated motor from being driven by the engine.
This invention will now be described with reference to the accompanying drawings which illustrate, by way of example, and not by way of limitation, one of possible embodiments of the system proposed herein.
The compressor C of the air conditioner is coupled by a first drive, namely, a belt and pulley drive P, to the engine E of the vehicle. An electric motor M is coupled in tandem to the compressor C by the first drive through the unidirectional clutch U constituting a second drive. The power supply to the said motor is derived from the battery of the vehicle.
At a traffic signal (or other place) when the vehicle stops
and the engine is shut OFF (under the influence of a stop-start
feature installed in the vehicle) with the compressor switch
ON, an electronic control unit senses the engine OFF and
compressor switch ON situation, to activate the motor M. The
said motor, on activation, drives the compressor,
uninterruptedly, through the said clutch, even after the engine is OFF, to provide continued air conditioning comfort to the occupants of vehicle.

When the engine is turned ON, thereafter, by the driver, say, on, the traffic signal permitting the vehicle to proceed, the engine resumes driving of the compressor through the first drive. The said control unit now senses the engine to have turned ON and de-activates the motor. The de-activated motor, however, is now disabled by the clutch, from being driven by the engine, since the said clutch acts positively only in one direction, but "slips" in the other.
It will be appreciated that various other embodiments of the system proposed herein are possible without departing from the scope and ambit of this invention.

We Claim:
1. A system for ensuring uninterrupted running of the engine-
driven air conditioner of a motor vehicle, even after the engine
has stopped, comprising an air conditioner, the compressor
of which is coupled to the engine by a first drive; an electric
motor coupled in tandem to the compressor by the first drive
through a second drive constituted by a unidirectional clutch,
the input power to the said motor being derived from the
battery of the vehicle; an electronic control unit (ECU) for
activating the motor only when the said unit senses the
engine to be OFF and the compressor switch to be ON, the
said motor, on activation, driving the compressor,
uninterruptedly, through the said clutch, unless the engine is
turned ON to resume driving the compressor through the first
drive; the said control unit, on sensing the engine to have
been turned ON, simultaneously de-activating the motor, while
the said clutch disables the de-activated motor from being
driven by the engine.
2. A system for ensuring uninterrupted running of the engine-
driven air conditioner of a motor vehicle, even after the engine
has stopped, substantially as herein described with reference