A method and apparatus for pre-tensioning a bolt that joins two parts, each end of the bolt being threaded into a respective cavity of the two parts. According to one embodiment, the bolt including a double wedge pre-tensioning element, a washer disposed at each side of the double wedge and clamping elements fastening the wedges once the desired preloading has been attained. The bolt is pre-tensioned with a tensioning tool which acts on the pre-tensioning element, reducing a distance between the wedges while increasing the distance between the two parts to be joined and reducing a distance between the outer facing surfaces of the wedges and washers. The control system measures at least one of the distances described, with the tensioning tool acting in accordance with the measured distance.

Tightening device can fasten a fastening element by a target tightening force with good accuracy and facilitate automation. The tightening device includes a cylindrical drive socket holding a nut in the lower end opening thereof; a nut holder disposed inside the drive socket, a bolt passing through a bottom thereof, and regulating movement of the nut held by the drive socket toward the tip end of a threaded par; a tension rod which is disposed inside the nut holder and the lower end face of which has a threaded hole into which a portion of the threaded part that is further on the tip end side than the nut is screwed; a sensor for detecting tension force; a first motor for turning the tension rod around an axis that extends in the vertical direction; and a second motor for turning the drive socket around an axis.

In a lifting and transporting device for lifting a load and transporting the load transversely to the lifting direction, for use in manufacturing a screwed flange connection, in order to bring a bolting tool into a bolting position, in which it is in engagement with a screw bolt connection to be tightened or to be released, or into a transport position in which it can be moved out of engagement with a screw bolt connection and can be transported to the next screw bolt connection, wherein the flange extends horizontally in the transport direction, comprising a frame which extends around a load space of specified size for picking up and lifting a load, a holding mechanism for holding the load, wherein the holding mechanism is movable relative to the frame in the lifting direction, and comprising a hoisting device which beside the load space is attached to the frame and is adapted for lifting and lowering the holding mechanism with a load attached thereto, wherein the frame is mounted on a first and a second support bearing whose supporting directions each extend perpendicularly to the transport direction and which have a distance to each other perpendicularly to the transport direction, wherein the first support bearing is designed for abutment against the flange upper side, and wherein at least the first support bearing includes sliding members or rollers which can be shifted or rolled off in the transport direction, the frame includes a first frame portion and a second frame portion, wherein the second frame portion is pivotally mounted on the first frame portion about an axis which extends in the transport direction, the first support bearing is attached to the first frame portion, the holding mechanism is mounted on the second frame portion so as to be shiftable in the lifting direction and is non-pivotably mounted with respect to the second frame portion about an axis extending in the transport direction, and the holding mechanism is configured to non-pivotably hold the load with respect to the holding mechanism about an axis extending in the transport direction.

Provided is a nut and a bolt tightening method for fastening an object, wherein a tightening force is applied on the object by rotating a nut or a bolt in a state in which a predetermined tension force is applied on the bolt in the axial direction of the bolt. When the tensile force exerted on the bolt decreases as the tightening force increases and after a timing when an inflection point occurs in a time course change in a ratio of an amount of change in the tensile force exerted on the bolt to an amount of change in an angle of rotation of the nut or the bolt, the tightening resulting from the rotation of the nut or bolt is terminated and the tensile force applied on the bolt is removed.

A fastening device for fastening a bolt to a fastening target object, wherein the bolt has a bolt head female screw section in an inner circumferential surface of a recess provided in an upper surface of a bolt head section. The fastening device includes a tension rod having a rod male screw section engaging the bolt head female screw section; a drive socket circumferentially surrounding the tension rod and having a lower end section with a grasper for laterally grasping the bolt head section; a supporter circumferentially surrounding the drive socket and having a lower end section protruding downward beyond a lower end section of the drive socket; a sensor for sensing compression force acting on the supporter in the upward/downward direction; a first motor for rotating the tension rod around an axis extending in the upward/downward direction; and a second motor for rotating the drive socket around the axis.

The present disclosure relates to a method for use in installation of a mill liner, the method including (a) retaining a mounting bolt at least partially within a liner opening extending through the mill liner, (b) positioning the mill liner against a mill shell so that the retained mounting bolt is aligned with a mill shell opening extending through the mill shell, (c) selectively coupling an extraction tool to the mounting bolt, the coupling performed by an operator outside of the mill shell, (d) detaching the mounting bolt from the liner using the extraction tool; (e) pulling the mounting bolt through the mill shell opening so that at least a portion of the mounting bolt protrudes outside of the mill shell, and, (e) securing a fastener onto the mounting bolt to thereby attach the mill liner to the mill.

The present disclosure relates to a method for use in installation of a mill liner, the method including (a) retaining a mounting bolt at least partially within a liner opening extending through the mill liner, (b) positioning the mill liner against a mill shell so that the retained mounting bolt is aligned with a mill shell opening extending through the mill shell, (c) selectively coupling an extraction tool to the mounting bolt, the coupling performed by an operator outside of the mill shell, (d) detaching the mounting bolt from the liner using the extraction tool; (e) pulling the mounting bolt through the mill shell opening so that at least a portion of the mounting bolt protrudes outside of the mill shell, and, (e) securing a fastener onto the mounting bolt to thereby attach the mill liner to the mill.

A tightening device for a screw connection and a safety device assigned to the tightening device are provided. The screw connection has a bolt and a nut resting on a support surface. The tightening device has a cylinder housing, a hydraulically driven piston arranged in the cylinder housing and moveable along an axis, an exchangeable bush which can be carried on the axis and screwed to the threaded bolt, and a carrier connectable to the threaded nut by force fit or form fit. To prevent jumping of the tightening device on breakage of the bolt, the safety device has a threaded sleeve and a protective arm. The threaded sleeve is arranged outside the cylinder housing and has an internal thread for engaging a threaded bolt adjacent to the bolt. The protective arm is attached to the threaded sleeve and extends over the cylinder housing of the tightening device.

Systems and methods can include applying, using a nut assembly including a first nut and a plurality of fasteners provided in respective threaded holes of the first nut, a first tensioning force for a stud of a hammer assembly. The systems and methods can also include applying, using the nut assembly, a second tensioning force for the stud of the hammer assembly. The first tensioning force can be applied with the first nut in a first orientation whereby a first end surface of the first nut faces a first direction and a second end surface of the first nut faces a second direction opposite the first direction. The second tensioning force can be applied with the first nut in a second orientation whereby the first end surface of the first nut faces the second direction and the second end surface of the first nut faces the first direction. The second tensioning force can be greater than the first tensioning force.

The present invention refers to a device for tensioning a connecting element fastened to a component to be tightened. The device comprises an engagement element connectable to the connecting element, and an actuating unit for translating a rotational movement applied to an actuating element into a translational movement of the engagement element relative to the component. Further, the device comprises a gear unit configured to transform an input torque applied to a transmission input element into an output torque applied to the actuating element which absolute value is higher compared to the input torque.