| 摘要 |
A device for tightening, prestressing and untightening a threaded joint has a body for mounting around a nut in the joint. The body is provided with pistons, actuated by pressure medium for providing an elastic elongation of a screw in the joint. Inclined planes are arranged to convert the axial movement of the pistons to a turning movement for turning the nut thereby achieving tightening or untightening of the threaded joint. The angle of the inclined planes are so adjusted that there is a suitable relationship between axial force and torque. |
