| 摘要 |
<p>PROBLEM TO BE SOLVED: To carry out positioning in three positions or more by means of an easier structure. SOLUTION: When a position of a first piston 12 integrally moving with a first piston rod 13 is controlled inside a first piston chamber 25, an end plate 18 is positioned in a first position P1 and a fourth position P4. When a position of a second piston 14 separated from a second piston rod 15 is controlled in a second piston chamber 30 arranged in parallel to the first piston chamber 25, the end plate 18 connected to the second piston rod 15 is positioned in a third position P3 in the midpoint between the first position P1 and the fourth position P4. When a position of a third piston is controlled in a third piston chamber arranged in series to the second piston chamber, the end plate 18 is positioned in a second position P2 in the midpoint between the first position P1 and the third position P3 via the second piston 14 on which the third piston rod 17 abuts.</p> |
