| 摘要 |
A threaded rod has a variable length and comprises one end provided to be connected to a first part. A nut cooperates with the threaded rod, with two channels extending diametrically through the nut. The first channel has a threaded wall and the second channel has a smooth wall, with the second channel forming with the first channel an angle preferably of about 15.degree.. The nut is pivotally mounted in a casing and has a protruding tail. A spiral spring is blocked between the tail and the casing, which casing further comprises a rear portion provided to be connected to a second part. |
