Abstract: An internal combustion engine having an engine block with a chamber disposed therein containing a reciprocating piston. A head is mounted on the head of the engine block for providing fuel to the chamber. The chamber is designed to have a first end with a first diameter that tapers inward to a second end that has a second diameter that is less than the first diameter and extends into a cylindrical portion such that the reciprocating piston reciprocates within the cylindrical portion.

Abstract: A two-cycle engine having improved performance characteristics includes a block and a cylinder head coupled to the block, the cylinder head defining a cylinder bore and a precombustion chamber. The head of piston located in the cylinder bore divides the bore into first and second variable volume intake chambers. An intake port allows fresh air to be drawn into the variable volume intake chamber and be compressed by the moving piston and delivered to the precombustion chamber. Fuel is added to the compressed air, which is heated, and then delivered to the variable volume combustion chamber. In one embodiment, the piston drives a crankshaft which is mounted both for rotation and for translation. Another embodiment of the invention is a lubricating system for a piston where movement of the piston up and down generates a pumping effect moving lubricant through the piston for lubricating piston rings.

Abstract: In a four-stroke cycle engine in which a combustion chamber is formed by a piston accommodated in a cylinder block and a cylinder head disposed in the cylinder block and respective two suction valves and two exhaust valves are disposed in the combustion chamber, the combustion chamber is divided into two combustion sections each in which one of the suction valves and one of the exhaust valves are disposed. A mixture in a theoretical air-fuel ratio is fed into one of the divided combustion sections and a mixture in an air-fuel ratio corresponding to an engine load is fed into another one of the divided combustion sections, and the air-fuel ratio being changed in response to the engine load. In a case where the mixture in an air-fuel ratio includes an exhaust gas, substantially the same operation is performed, but in this case, the degree of opening of an exhaust gas recirculation valve is controlled so as to control the air-fuel ratio of the mixture.

Abstract: An internal combustion engine has an auxiliary cell connected thereto by a transfer valve. Approximately isothermally compressed gas, which may be a combustible mixture, is introduced into the cell through an input valve. A displacer piston in the cell is biased toward lower volume of the cell. In an illustrated embodiment, the displacer piston is translated by the compressed gas toward a larger volume in the cell. When the cell is fully charged with compressed gas, the input valve is closed and the transfer valve is opened for intermittently discharging the mass of gas in the cell into the cylinder of the internal combustion engine. The displacer piston displaces substantially all of the gas from the cell into the engine. Combustion is initiated and may, at least in part, occur within the cell, providing power to the engine as the gas expands and performs work by way of the engine piston.

Abstract: A combustion system for internal combustion engines having an exhaust gas recirculating system which is operable by a lean air-fuel mixture without aggravation of the combustion. The piston of the engine has a sub-piston projecting on the top thereof and the cylinder head is formed with a recess into which the sub-piston is insertable at a position near the top dead center of the stroke of the piston such that the space between the cylinder head and the piston can be divided into two combustion chambers. The compression ratios of both chambers are different from each other. An ignition plug is disposed in the chamber having the lower compression ratio, and ignition of the air-fuel mixture in the chamber having the higher compression ratio takes place by flame from the lower compression ratio chamber as a torch ignition.