This invention relates to improvements in reversible four-stroke cycle engines of the Diesel or slow-combustion type, and more especially to engines of the above class in which the cylinder, or each of the cylinders, has two mechanically actuated valves, each of which valves are connected by means of suitable pipes or ducts to a multiple-way valve or an equivalent device.
The object of the invention is to provide means by which the engine by the introduction of a pressure agent into the combustion chamber or chambers can be reversed or started in the desired direction.
The main feature in the invention is that each cylinder has a special exhaust device which always is opened at or near the lower or outer dead centre, and that the multiple-way valve, or an equivalent device, is in connection with the pressure vessel or receiver and the atmosphere in such manner that when the same connects the one valve with the pressure vessel, the other valve is in communication with the atmosphere and vice-versa.
The chief novelty claimed by the inventor is a four-stroke cycle engine, the cylinder or each of the cylinders of which has two mechanically actuated valves, each of which can act alternately as inlet and exhaust valve, and which are connected by suitable pipes or the like to a multiple-way valve or any equivalent device, wherein each cylinder has an extra exhaust device having its time of opening, etc, always at or near to the lower dead centre, the above-mentioned multiple-way valve being in connection with a pressure vessel or receiver and the atmosphere.
The duration of the opening of the two valves in the cylinder head may be varied.
Should the engine not have a sufficient number of cylinders to avoid having a dead centre it may be transformed by any suitable arrangement into a two-stroke cycle engine during starting. For this purpose, for instance, double cams and double levers may be provided for each of the valves mentioned in such manner that air pressure is admitted to the cylinders for each downward stroke of the piston.