Indexing rotary actuator with clutch pistons

An indexing rotary actuator, having an output shaft rotatable in a single direction about a central axis of the indexing rotary actuator through a specific angle per each indexing, comprising:

• a pair of symmetrical housing members mounted together to form an actuator housing, the output shaft extending through opposite first and second ends of said actuator housing along the central axis of the indexing rotary actuator, said actuator housing including therein
• a main piston chamber disposed annularly about the central axis of the indexing rotary actuator along an outer circumference of said actuator housing, and
• a clutch piston chamber disposed along the central axis of the indexing rotary actuator within a central portion of said actuator housing including the output shaft;
• first and second main pistons rotatable around the central axis of the indexing rotary actuator within said main piston chamber;
• first and second piston mounting rings mounted within said clutch piston chamber with respective first faces opposing each other, the output shaft extending through central portions of said first and second piston mounting rings, said first and second main pistons respectively being affixed to outer peripheral surfaces of said first and second piston mounting rings to be rotatable within said clutch piston chamber around the central axis of the indexing rotary actuator, said first and second piston mounting rings respectively including second faces opposite said first faces;
• first and second clutch pistons respectively mounted within said clutch piston chamber opposing said second faces of said first and second piston mounting rings, said first and second clutch pistons respectively being slidably supported within said clutch piston chamber along the output shaft toward and away from said first and second piston mounting rings to be engaged and disengaged with said first and second piston mounting rings;
• and
• fluid drive means, operatively coupled to said first and second main pistons respectively through said first and second piston mounting rings and said first and second clutch pistons, for alternately driving said first and second main pistons around said main piston chamber, rotational movement of said first and second main pistons being translated to the output shaft respectively via said first and second piston mounting rings and said first and second clutch pistons,
• said first and second piston mounting rings including respective first and second raised arcuate sectors formed upon said first faces which cooperate to limit rotation of said first and second main pistons around the central axis of the indexing rotary actuators thus limiting rotation of the output shaft in a single direction through the specific angle per each indexing.