The present invention relates to "Auto decompression actuating mechanism" used on two and three wheelers.
Normally in any 2 and 3 wheeler vehicles the engines are started by cranking a crankshaft by operating a leg operated or hand operated lever and gear train. Some of the engines are provided with self-starting by electric motor. Some engines use a hand lever operated decompression valve to reduce the cranking effort. Decompression valve, when operated helps to releases part of the compressed charge from combustion chamber to outside, reducing the volume of charge to be compressed, lowers pressure acting on piston, and hence less cranking effort. This valve is manuaHy closed at moment of start of the engine. Operating lever is normally mounted at handle bar or panel.
Operating decompression lever and valve needs precise manual control by one hand. Sspecialfy when to release a lever to close the vafve, to start ancf keep engine in mnning condition. If closing is not done precisely, a large amount of effort and cylinder charge will be WcT^ited. At starling, som^Vmes, a drrc/^e lever ^rsD needs \o be operated manually. Operating decompression lever and choke lever simultaneously manually ,and operating hand starter lever/leg starter lever is a very difficult task.
It is therefore an object of this invention to overcome the above problem by providing a cam-puWey -cab/e arra^ement to precisely '^n arvdi d/ase the decompression valve automatically during the engine cranking.
The Invention will now be explained in detail with reference to the following drawing-Figure 1 is a side view of a typical two-stroke engine showing the proposed arrangement.
Figure 1; consists of a two-stroke engine E consisting of a cylinder head 4 provided with a spark plug 1. A piston 6 is reciprocating inside the bore 5a of a cylinder block 5 operated by a connecting rod 7. The engine E is started by any known means of kick-starter an^angement through kick shaft 8, which is housed in the engine cover 9. A lever 10, which can be either hand operated or leg operated, operates the kick shaft 8. A pulley 111s mounted on the kick

shaft 8. A decompression valve 2 is mounted on the cylinder head 4.A decompression camshaft 12 is mounted on the pillars 4a and 4b provided on the cylinder head 4 just above the decompression valve 2. A pulley 3 rotates the decompression camshaft 12 operated by a cable 13, which passes through the pulleys 3, and pulley llThe outer cover of the cable 13 is held in position by an abutment bracket 14, which is fitted on the engine cover 9.
The working of the system is as follows;
VMhen the \ever 10 is operated either by hand or leg, the kick shaft 8 rotates the pulley 11, which results in pulling the c.able 13, which in turn will rotate the pulley 3 mounted on decompression camshaft 12. This will result in the decompression camshaft 12 opening the decompression valve 2. The amount of lift of camshaft 12 and cam timing is optimized to give precise opening and closing events for decompression valve 2. Since this mechanism operates automatically, no manual control is required.
Even though the above explanation is given for a typical two-stroke engine, a similar arrangement for actuating the exhaust or decompression valve provided on a four-stroke engine for decompression is possible.
It will be appreciated from the foregoing description that various other embodiments are possible.

We Claim:
l.An auto decompression actuating mechanism for a two wheeler or three wheeler motor vehicle comprising a manually operated lever, for actuating the kick shaft; a first pulley rotatable by the actuated kick shaft to pull a cable connected thereto: a decompression cam shaft with a second pulley mounted thereon, the cable being connected to the second pulley such that when the cable is pulled the second pulley rotates and causes the decompression shaft to rotate and open the decompression valve.
2. An auto decompression actuating mechanism for a two wheeler or three wheeler motor vehicle substantially as herein described with reference to and as illustrated in the accompanying drawings