| 摘要 |
A device for providing relative movement between three telescopically co-ordinated parts (1, 2, 3) comprises a power means (7) of a type variable in length and acting between a point (8) on a first (1) and a point (9) on a second (2) of the parts, and a flexible traction element (12), which is arranged to cause relative movement between on one hand the third part (3) and on the other hand said first and said second parts (1, 2) by transmitting forces between the first and the third parts when relative movement between the first and second parts (1, 2) is effected by the power means. The power means located externally of the parts is designed with a longitudinal internal passage (13), in which the traction element extends in its extension between a point (14) on the third part and a point (15) fixed in relation to the first part (1), whereby the power means will operate as a casing variable in length for the traction element. |
