Device for tightening, prestressing and untightening a threaded joint
AssigneeAB Motala Verkstad
InventorRoland Fredriksson
Life of this patent
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Abstract
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.
Claims6
A device for tightening, prestressing and untightening a threaded joint where great prestressing accuracy is required comprising, a body having an opening therein for receiving an elongated internally threaded member forming part of said joint, pressure actuated piston means in said body adapted to impart axial movement thereto, and means having inclined surfaces carried by said body for converting said body axial movement into rotational movement of an elongated threaded member received in said body for tightening or untightening the threaded joint.
Dependencies are inferred from the claim text.