Describes an invention wherein the main charge is compressed to a degree just below its point of ignition, and a charge of some body having a lower ignition point is injected, and ignites. This body may be gaseous liquid or pulverulent, and may be previously heated to modify its igniting point. It is introduced into the cylinder through a special valve located between the main inlet and the exhaust valves.
The ignition charge is supplied from a reservoir fitted with an adjustable safety-valve, and this charge may be impregnated, on its passage to the cylinder, by liquid or pulverulent fuel from a suitable receptacle having a revolving plug with a measuring cavity. The temperature of combustion of the working charge can be varied by mixing it with the residual products or by preliminary heating.