| 摘要 |
PURPOSE:To adjust a gas pressure in a main tube in a state that the maximum elongation size of a piston rod is held at a constant value only by rotating a main tube based on a subtube. CONSTITUTION:A subtube 2 is joined in a screwed-in state with one end side of a main tube 1 and a stopper 8 with the other end side. Under the maximum elongation state of a piston rod 6, the piston rod 6 and the stopper 8 are integrally formed by means of an engaging pin 9. Thus, in a state that the piston rod 6 is brought into a maximum elongated state, a gas pressure in the main tube 1 is adjusted in a way that the subtube 2 is caused to insert in and pull out from the main tube 1 only by rotating the main tube 1 based on the subtube 2 in an arbitrary direction. Further, the stopper 8 is also rotated relatively to the main tube 1 and a distance between the subtube 2 and the main tube is held at a constant value. |
