| 摘要 |
A coupling device (3) for connecting to an element (14) provided with threads (26), comprising a first rotary body (2) and a second rotary body (4) mounted on the first rotary body and coaxially therewith, where the first rotary body (2) is equipped with a threaded connection (8, 26) for connection to the element (14) via the threaded connection (26) and means (11, 18) for rotation of the coupling device. Between the rotary bodies (2, 4) there is provided a counter-threaded connection (6a,b) with a pitch which is oppositely directed to the pitch on the threaded connection (26), whereby, when it is secured while the first rotary body (2) is rotated in the threaded connection (26) in the element (14), the second rotary body (4) is also moved towards the body (14) by means of the counter-threaded connection (6a,b). A device (110) to effect relative rotation between a first body (2) and a second body (4) which is arranged coaxially with the first body, comprises a first coupling element (117) which is movable between a coupled position and an uncoupled position relative to the first body (2), and a second coupling element (118) which is movable between a coupled position and an uncoupled position relative to the second body (4), together with means for ensuring that the first and second coupling elements' (117, 118) movements between the coupled and uncoupled positions are undertaken substantially along the said first and second bodies' (2, 4) longitudinal axes. |
