CRANKCASE BREATHER VALVE FOR ENGINES WITH SYNCHRONOUS PISTON MOVEMENT

摘要

A crankcase breather valve for ventilation and pressure control within the crankcase of an internal combustion engine in which pistons stroke upwardly and downwardly in a synchronous movement. The valve is inserted into a breather hose which conducts gases into and out of the crankcase. The valve comprises a resili ent valve member preferably an elastomeric umbrella-type seal spaced above a seal se at and forming a gap therebetween through which gases may flow either direction dur ing portions of the pistons stroke cycle. The valve construction permits three opera ting modes: firstly to permit the egress of positive pressure gas out of the crankcas e and through the gap while the pistons stroke downwardly; secondly, to permit the ing ress of a small amount of gas back through the gap into the crankcase when the crankcase pressure changes from positive to negative; and thirdly to check further ingress of gas into the crankcase at greater crankcase suctions developed when the pistons are moving upwardly.