This invention relates to kill switch device for a motorcycle. A "motorcycle", in this specification, means and includes not only a motorcycle popularly known as such, but also a motor driven two wheeler vehicle, such as a scooter, a three wheeler motor driven vehicle such as an autorickshaw or a motor driven vehicle for the disabled, or any other similar multi-wheeled vehicle.
The known kill switch is positioned on the handle bar of a motorcycle and the purpose of such switch, when manually operated by the rider, when the vehicle is in motion, is to switch off the ignition and thereby cut off power to the engine, to bring the vehicle to a halt. This is normally done when the engine has reached a speed equal to the engine idling speed.
However, the drawback with the known kill switch is that there is the possibility that the said switch may be inadvertently operated by the rider when the vehicle is at high speeds. At such speeds, suddenly cutting off power to the engine may cause serious accidents since the rider loses control over the vehicle.
Furthermore, operation of the kill switch at high speeds results in the unbumt gases emitted from the engine creating pollution problems.
It is therefore an object of this invention to propose»a kill switch device which is free from the above mentioned drawbacks. The said device is intended for being mounted on the handle bar of the vehicle or at any other convenient place.
In other words, the kill switch proposed herein will operate only at or below a predetermined low speed of the engine, thus avoiding hazardous situations. Operation at such speed will minimized pollution effects, since the volume of unbumt gases emitted after cutting off of the ignition will be substantially less than that emitted at higher speeds. The kill switch device for a motorcycle, according to this invention, comprises said microcontroller being provided for the ignition circuit of the motorcycle. sensing the engine speed, the ^iJi^ for switching off the ignition, on operation of the pushbutton switch is- -««t only when the engine speed falling to or below a predetermined value.
This invention will now be described with reference to the accompanying drawing which illustrates, by way of example, the circuit layout of one of possible embodiments of the kill switch device proposed herein.

A microcontroller M is connected to a manually operable spring-loaded pushbutton switch S.
The said microcontroller M is provided for the ignition circuit C of the engine of the motorcycle.
The microcontroller is M intended to sense the engine speed and this is done when it senses the rpm of the alternator A which is related to the engine speed.
It is only when the engine speed falls to a predetermined low speed, such as, the idling speed, that the microcontroller will be activated, on the pushbutton being manually operated, to switch off the ignition circuit.
Once the pushbutton is pressed and released, it reverts to its normal position, under spring loading. When the engine has to be started once again by the rider, this will have to be done in the normal way. The pushbutton can then be used again, in the manner indicated above, to switch off the ignition, when required.
Thus, in the device proposed herein, the pushbutton is inoperative at speeds higher than the predetermined speed, such as, the idling speed, thus preventing hazardous consequences at high speeds by inadvertent operation of the said switch.
At low speeds when the pushbutton switch is operated, unbumt gases resulting after the switching off of the ignition are lesser in volume than the volume of unbumt gases resulting after switching off of the ignition at high speeds.
The predetermined speed will be any low value, such as the idling speed or a speed just above the idling speed. The pushbutton will therefore be operative at such speed.
The terms and expression herein are of description and not of limitation, in as much as various other embodiments of the device proposed herein are possible without departing from the scope and ambit of this invention.

We claim:
1. A kill switch device for a motorcycle comprising a microcontroller
connected to, a manually operable pushbutton switch the said
microcontroller being provided for the ignition circuit of the motorcycle, for
sensing the engme speed and for switching off the ignition, on operation of
the pushbutton, only on the engine speed falling to or below a predetermined value.
2. A kill switch device substantially as herein described and illustrated in the
accompanying drawings.