Patent ID: RE41373

Claim:
A rotary engine comprising a housing having a first and second intersecting cavity disposed therein, the first and second cavities including cylindrical wall surfaces; a rotor rotatably mounted in the first cavity, the housing and the rotor defining an annular chamber disposed therebetween, the rotor including a piston extending from the rotor into the annular chamber; a first valve rotatably mounted in the second cavity, the first valve having a circumference and recess sized to accommodate the piston during a rotation of the rotor; and at least one passage comprising an open portion formed in the cylindrical wall surface of the second cavity and an enclosed portion enclosed by the housing along a length of the enclosed portion, the open portion including a leading end and a trailing end with respect to a direction of rotation of the first valve and which open portion extends for at least about 20 degrees around a circumference of the cylindrical wall surface of the second cavity, and wherein the enclosed portion connects the open portion to the annular chamber downstream of the second cavity relative to a direction of rotation of the rotor ; and wherein a distance between the leading end of the open portion and the intersection of the first and second cavities located on an upstream side of the second cavity with respect to the direction of rotation of the first valve is greater than a width of the recess at the circumference of the first valve, and wherein a distance between the leading end of the open portion and the intersection of the first and second cavities located on an upstream side of the second cavity with respect to the direction of rotation of the first valve is greater than a width of the recess at the circumference of the first valve .