| 摘要 |
PURPOSE:To enable a piston rod to stop at four positions certainly with a simple structure by receiving a triple piston into a cylinder so as to be relatively displaceable. CONSTITUTION:An empty outer piston 3 is received into a cylinder 1 to slide in contact freely, and an intermediate piston 4 composed of the first ad the second intermediate pistons 4a, 4b is received into the outer piston 3 to slide in contact freely. Similarly, an inner piston 5 with a piston rod 5a provided on one end is received into the intermediate piston 4 to slide in contact freely. Also, the bore of moving range, or the end opposite to the piston rod 5a, of the outer piston 3 is made in a bigger size than that of other parts. The piston rod 5a can be certainly stopped at four positions with simple structure by the above mechanism. |
