Patent ID: 8646376

Claim:
A double rack and pinion oscillating device comprising: a body having a first end and a second end on the side opposite thereto; a first cylinder hole and a second cylinder hole arranged in the body so as to extend from the first end to the second end parallel to each other; a first piston and a second piston that slide in the first and second cylinder holes, respectively; racks provided in the pistons; an output shaft having a pinion meshing with the racks; first pressure chambers formed on the first end side of the first and second cylinder holes by the first and second pistons; second pressure chambers formed on the second end side of the first and second cylinder holes by the first and second pistons; a first air flow path connecting the second pressure chamber of the first cylinder hole and the first pressure chamber of the second cylinder hole; and a second air flow path connecting the first pressure chamber of the first cylinder hole and the second pressure chamber of the second cylinder hole, the first and second pistons being driven synchronously in opposite directions relative to each other by compressed air supplied to the first air flow path and the second air flow path, and the output shaft being thereby rotationally oscillated around its axis, wherein a first opening of one end of the first cylinder hole and a second opening of one end of the second cylinder hole open at the first end of the body and are sealed by a first end cap and a second end cap, and a third opening of the other end of the first cylinder hole and a fourth opening of the other end of the second cylinder hole open at the second end of the body and are sealed by an end plate, wherein a first port connecting to the first flow path, a second port connecting to the second flow path, and adjusters are provided in the end plate, tips of the adjusters protruding into the second pressure chambers of the first cylinder hole and the second cylinder hole, respectively, wherein on an outer periphery of each of the first end cap and the second end cap, a plurality of ring-shaped sealing members are spaced at intervals in the axial direction of the end cap, and ring-shaped flow paths are formed between adjacent ring-shaped sealing members, and wherein part of the first air flow path is formed by the ring-shaped flow path of the first end cap, and part of the second air flow path is formed by the ring-shaped flow path of the second end cap.