When an engine, on whose shaft disk 1 is mounted, exceeds a preset speed, weight 2 moves outward, beyond the circumference of the disk, as a result of centrifugal force and strikes the end of rod 3. When rod 3 moves to the right, ring a releases sleeve 4. While the engine is running at normal speed, sleeve 4 is held against ring a by spring 5. Spring 5 is stronger than spring 6 and therefore holds valve member 7 open in the fuel supply line. When sleeve 4 is released, spring 6 closes off fuel supply to the engine.
$3979$LHP,FD$