This invention is for an improved method of igniting in slow-combustion engines in which the ignition is effected by the heat of compression generated in a chamber.
On the up-stroke of the compressing piston air, from the combustion chamber, passes into a small auxiliary cylinder through ports communicating with the combustion chamber in the main cylinder, and at the end of the compression stroke of the working piston this air is forced back into the combustion chamber by the downward movement of a piston provided in the auxiliary cylinder, and the heat generated by the extra compression in the auxiliary cylinder is sufficient to ignite the charge.
An explosive mixture formed with powdered or other fuel may be admitted to and ignited in the auxiliary cylinder, a suitable passage being provided for the admission of such fuel. The movements of the piston may be effected by means of compressed air.
The engine may be started by compressing a charge in the cylinder and igniting it by compressing air or an explosive charge in the auxiliary cylinder. Inert gases may be used in the auxiliary compressing cylinder and for the formation of the working charge.