FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
An Improved Battery Disconnect Switch For An Automobile
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
AJAY N PALKAR and ANIL K NAHIRE
All Indian Nationals of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following complete specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
This invention relates to an improved battery disconnect switch for an automobile vehicle and is particularly but not exclusively applicable to vehicles run on compressed natural gas.
BACKGROUND OF INVENTION
Conventional battery cut-off-or disconnect switches used in vehicles like buses take care of disconnecting the battery when the vehicle is kept idling for a long period. While the engine is kept running, electric power is supplied through the alternator which is connected in parallel to the battery.
But under emergency condition, the driver may have to jump out of the vehicle. He may forget to switch off the ignition of the vehicle. A battery cut-off switch is provided which is accessible from outside. This switch when operated disconnects the battery but keeps the engine running as the power supply is maintained through the alternator. Hence, the Engine Management System being powered through Alternator keeps the engine running.
In conventional electrical system of a vehicle, as best shown in FIG. 1, includes a battery electrically connected to an alternator and an ON-OFF switch (also called battery cut-off switch) associated with the battery. The battery and the alternator are connected, in parallel, to the ignition switch and other vehicle electrical loads. The battery cut-off switch is adapted to connect and disconnect the battery as and when desired, for example when the vehicle is to be kept idle for a longer period of time. Typically, the battery cut-off switch is also accessible from outside of the vehicle. Therefore, in under emergency e.g. during a fire incidences, a driver may jump out of the vehicle and may then turn off the battery cut-off switch from outside.

However, the cutting-off of the battery has no effect on the engine and the engine continues to be in operation even after the disconnection of the battery because of power is being supplied through alternator. In Fig. 1, S and A represent the starter motor and the alternator.
As would be apparent to those skilled in the art, a conventional switch, as shown in FIG. 3, includes a pair of spaced part positive metallic nodes and a pair of spaced apart negative metallic terminals. Each of the pair of spaced part positive metallic nodes and pair of spaced apart negative metallic terminals are electrically coupled to the terminals of the battery. Each of the pair of spaced part positive metallic nodes and a pair of spaced apart negative metallic terminals are provided on a nonconducting plate. A cap with a pair of metallic inserts is also provided on the switch. When the switch is operated the metallic inserts electrically connect or disconnect the pair of spaced part positive metallic nodes and a pair of spaced apart negative metallic terminals, respectively, thereby cutting the battery OFF or ON.
OBJECTS OF INVENTION
Main object of this invention is to provide a switch accessible from outside which when operated would disconnect the battery as well as switch off the power supply to the ignition. Running of the engine is therefore stopped even though the ignition is not switched off.
SUMMARY OF INVENTION
Till now a circuit breaker has been used to switch off only battery. The improved switching mechanism with auxiliary contact enables the driver to switch off the battery and the engine from drivers seat or from outside of the vehicle.

The improved battery disconnect switch for an automobile vehicle according to this invention comprises of an additional auxiliary contact circuit breaker. The main contact is used to disconnect battery and the auxiliary contact is used to disconnect power supply to Engine Management System through relay control. This results in disconnection of battery and ignition supply simultaneously.
The object of the present invention is to provide an improved battery disconnect switch for an automobile comprising an auxiliary contact circuit breaker connected to the battery cut off switch for breaking contact with the battery and engine, said auxiliary contact being connected through a relay control to the ignition switch for switching off the engine simultaneously with the switching off of the battery
BRIEF DESCRIPTION OF DRAWINGS
Fig.l is the circuit diagram of the conventional switching off system. (Prior Art)
Fig. 2 is the circuit diagram showing the auxiliary contact connected through the
relay and limit switch.
Fig.3 is the conventional battery cut off switch. (Prior Art)
Fig. 4 is the battery cut off switch as per present invention.
DETAILED DESCRIPTION OF INVENTION
This invention will now be described with reference to the circuit diagrams shown in the accompanying drawings. The objective of the invention is to provide a means for turning off the engine when the battery is cut off.
Improved feature of the present invention is clearly shown in Fig. 2. An auxiliary contact represented by AC is connected to control relay (3) through a limit switch

(2). When the limit switch (2) is actuated, the auxiliary contact (1) breaks the contact relay (3) there by switching off the engine as well as the battery (6).
As shown in Figure 2, the system for turning off an engine of the present invention also includes an auxiliary contact (1), in addition to the elements of the conventional electrical system. The function of the auxiliary contact (1) is to turn off the engine when the battery (6) is cut off. The system for turning off an engine of the present invention furthermore includes a receptacle limit switch (2) which is in series with the auxiliary contact (1). The auxiliary contact (1) is a switch and is provided between the alternator (5) and the Control relay coil (3) and the ECU (7). The ECU (7) supply is controlled through the auxiliary contact (1) and control relay (3). When the auxiliary contact (1) in disconnected the power supply from the alternator (5) to the ECU (7) through Relay contacts (3) is being stopped. With the power supply to the ECU (7) stopped, the engine also stops.
For the purpose of switching the auxiliary contact (1) ON or OFF, a novel switch is also provided in the present invention. As shown in FIG. 4, the novel switch, in addition to the parts of the conventional switch, includes an additional set of terminal (10) on the line joining the alternator (5) to ECU (7), i.e. the line supplying the power supply to the ECU (7). The novel switch also includes an additional contact configured to electrically couple the additional set of terminal. When the novel switch is operated the metallic inserts and the additional insert electrically connect or disconnect the pair of spaced part positive metallic nodes, a pair of spaced apart negative metallic terminals and the additional contacts, respectively, thereby cutting the battery (6) OFF or ON and disengaging or engaging the alternator (5) with the ECU (7) simultaneously.
Means for breaking the circuit may be provided outside the vehicle so as to provide access to the operator in the event of an emergency.

Obvious modifications and alteration fall within the scope ambit of the appended claims.
Reference Numerals Description
1 - Auxiliary Contact
2 - Limit Switch at Receptable
3 - Control Relay
4 - Starter Motor
5 - Alternator
6 - Battery cut-off switch with Auxiliary Contact
7 - To ECU/EMS Control
8 - To Ignition Switch & Vehicle EL Loads
9 - From Ignition Switch
10 - Additional Auxiliary Contact
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

WE CLAIM
1. An improved battery disconnect switch for an automobile comprising an auxiliary contact circuit breaker (10) connected to a battery cut off switch for breaking contact with the battery (6) and engine, said auxiliary contact circuit breaker (1) being connected through a relay control (3) to a ignition switch (9) for switching off the engine simultaneously with the switching off of the battery (6).
2. The improved battery disconnect switch for an automobile as claimed in claim 1, wherein said auxiliary contact circuit breaker (1) is connected to said relay control (3) through a limit switch (2).
3. The improved battery disconnect switch for an automobile as claimed in claims 1 and 2, wherein means for actuating the circuit are located at a position accessible from outside the vehicle.
4. The improved battery disconnect switch for an automobile as claimed in claims 1 to 3 comprising of auxiliary contact circuit breaker connected to battery cut off switch fitted on a vehicle.


ABSTRACT
An Improved Battery Disconnect Switch For An Automobile
This invention relates to an improved battery disconnect switch for automobile vehicle. It comprises of an auxiliary contact circuit breaker connected to the switch at one end and to a control relay at the other through a limit switch. The control relay switch is in turn connected to the ignition switch. This enables switching off the battery simultaneously with the switching off of the engine.
Fig 2