(under subclass 75) Internal-combustion engines of the reciprocating type working upon a modified four-stroke cycle with recompression in the working cylinder, as defined in the definition of ..., below, and in which air unmixed with combustible is drawn into and expelled from the working cylinder one or more times upon distinct suction and expelling strokes of the working piston after the end of the exhaust-stroke and before the beginning of the suction-stroke of the normal four-stroke cycle, whereby a more complete removal of the burned gases, from the working cylinder and combustion-chamber is secured.
