Abstract: In order to reduce the mass of a rocker arm and simultaneously simplify the adjustment of the valve clearances the rocker arm is pivotally mounted on a universal joint so that it may tilt and establish a three point contact between the universal joint and the tops of the two valve stems. By incorporating a hydraulic lifter in the universal joint arrangement constant lash free automatic zero clearance adjustment is rendered possible. Utilizing a roller as a cam follower permits a reduction in valve train friction loss. To prevent the rocker arm from meandering retaining flanges are provided on the rocker arm which envelope the tops of the valve stems.

Abstract: In order to accurately control the operation of the engine while still achieving near optimal swirl rate control, the swirl is controlled by a valve which is separate from the engine throttle valve and which is basically controlled in response to the pressure prevailing across the same. Various operating parameters such as the instant air-fuel ratio of the charge being combusted in the combustion chambers are utilized to modify prerecorded values to those which will induce the best setting for the valve.

Abstract: The invention provides a character recognition apparatus having an original feature extracting section for extracting as an original feature a feature deliberately neglected in the processes of pre-process conversion and recognition feature extraction. The original feature extracted by the original feature extracting section is used for final recognition of a set of characters, thus preventing erroneous character recognition.

Abstract: A spark-ignition internal combustion engine with multiple plugs is operated at an air-fuel ratio around the stoichometric under a high EGR rate higher than EGR limits for stable operation in a single spark plug ignition engine.

Abstract: An engine is provided with two spark plugs in each combustion chamber to ignite stoichiometric air-fuel mixture mixed with a large proportion of inert gases to lower NOx emission level. The engine is equipped with hydraulic valve lifters which are mechanically connected to intake and exhaust valves to control the valve overlap of the intake and exhaust valves. By the action of the valve lifters, the valve overlaps are increased in the normal driving operation range of the engine to prevent discharge at the terminal stage of exhaust valve opening exhaust gases containing a considerably large amount of hydrocarbons.

Abstract: An internal combustion engine of the reciprocating piston type, which is provided with an exhaust gas recirculation circuit to suppress the formation of NOx and has two or three spark plugs for each combustion chamber. There is a substantial overlap of the opening periods of exhaust and intake valves, so that a portion of the combustion gas is left unexhausted. The combustion chamber has a simple shape such as hemisphere, and the spark gaps of the plural spark plugs are arranged distant from each other in each combustion chamber so as to respectively share approximately equally divided portions of each combustion chamber. The number of the spark plugs is two when the volume of the recirculated exhaust gas, including the unexhausted combustion gas, is about 50% at the maximum of the volume of air admitted into the combustion chamber but three when the recirculated exhaust gas amounts to about 60% of the air at the maximum.

Abstract: An internal combustion engine of the reciprocating piston type, which is provided with an exhaust gas recirculation circuit to suppress the formation of NOx and has two or three spark plugs for each combustion chamber. There is a substantial overlap of the opening periods of exhaust and intake valves, so that a portion of the combustion gas is left unexhausted. The combustion chamber has a simple shape such as hemisphere, and the spark gaps of the plural spark plugs are arranged distant from each other in each combustion chamber so as to respectively share approximately equally divided portions of each combustion chamber. The number of the spark plugs is two when the volume of the recirculated exhaust gas, including the unexhausted combustion gas, is about 50% at the maximum of the volume of air admitted into the combustion chamber but three when the recirculated exhaust gas amounts to about 60% of the air at the maximum.

Abstract: Two spark plugs are disposed in each combustion chamber of an internal combustion engine to ignite the air-fuel mixture mixed with a considerably large proportion of the exhaust gases. The wall surface of the combustion chamber is formed so that only one spark plug can not be excessively cooled down by the stream of the cool air-fuel mixture inducted through the intake port of the engine.

Abstract: A reactor is made deformable by thermal stresses, as the construction thereof includes accordion type portions. The reactor comprises an inner core shell containing inlet and outlet pipe sections formed integral therewith, and extending outwardly through an outer core shell to an outer shell member. Each shell member consists of first and second shell counterparts which may be fixed together in a common plane.

Abstract: An internal combustion engine equipped with a catalytic converter for catalytically purifying the exhaust gases discharged from the combustion chambers of the engine. The oxygen-combustibles ratio of the exhaust gases introduced to the catalytic converter is normally controlled to a predetermined level suitable for the reaction within the catalytic converter in response to the composition of the exhaust gases upstream of the catalytic converter. However, the secondary air is continuously supplied to the catalytic converter regardless of the oxygen-combustibles ratio of the exhaust gases during cold start or warmup of the engine to rapidly raise the temperature within the catalytic converter to a level over which the catalytic converter effectively functions.

Abstract: Each combustion chamber of an internal combustion engine is equipped with at least two simultaneously working spark plugs which are arranged distant from each other and located out of a central region of the combustion chamber, and an exhaust recirculation circuit including a flow control valve is arranged to recirculate exhaust gas to a nearly stoichiometric air-fuel mixture to be fed to the engine at a high recirculation rate on the maximum of 12-40% by volume of the quantity of air drawn into the engine.

Abstract: An internal combustion engine is disclosed in which each pair of cylinders has a Siamese exhaust port. Each of the exhaust ports is designed so that the ratio of a surface area (F) exposed to the exhaust gas discharged from one of the cylinders to the minimum cross-sectional area (S) through which the exhaust gas flows (F/S) ranges from 3 to 6.