A screw fastening apparatus for fastening a screw member having a bearing surface with respect to a member to be fastened by rotating the screw member from a theoretical seating point to a target rotational angle, including a rotational angle sensor which senses rotational angle values of the screw member for fastening the screw member, a torque detector which detects torque values for fastening the screw member, a torque value difference detector which detects a plurality of torque value differences, each of the torque value differences is a difference of the torque values detected at intervals of a constant rotational angle, a slip detector which detects a slip of the screw member with respect to the member to be fastened, from an average of the torque value differences, and a screw fastening discontinuing unit which instructs to discontinue the screw fastening when the slip is detected by the slip detector.

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 displaceable maintenance device, to a displaceable assembly device, to a method for servicing a fastening element, and to a method for servicing and/or assembling a fastening element of a flange of a wind power installation tower. Provided is a displaceable maintenance device for a wind power installation tower, comprising a mobile unit which is specified for moving the maintenance device along a flange of the wind power installation tower; a first maintenance unit having an impact element for impacting a fastening element, in particular a flange connection element, and a noise-receiver unit for detecting a noise generated by the impacting; a control unit for evaluating the noises detected by means of the noise-receiver unit, said control unit, based on the evaluation, being specified for assigning a maintenance status to a fastening element.

A device for tightening a screw connection on a flange connection has a tool carrier movable along the flange connection and provided with a traction drive. A tool on the tool carrier is provided for tightening the screw connection. A control unit is provided to move the tool carrier into a working position by traction drive control signals. The control unit controls, by tool control signals, tightening of the screw connection. On the tool carrier, a holding tool with counter-holding surfaces is arranged. The counter-holding surfaces are provided to bear against the threaded element of the screw connection. The tool carrier has a drive for moving the holding tool between a rest position and a counter-holding position. In the counter-holding position, the counter-holding surfaces bear against the threaded element. The control unit is additionally provided to control the drive of the holding tool by holding tool control signals.

A lock ring tightening mechanism includes a rotary pawl carrier disposed in a radial guide track and moveable by a piston connected to the rotary pawl carrier and a ratcheting lock ring configured for rotational actuation in a tightening direction by actuation of the rotary pawl carrier by the piston. A return spring is configured to return the rotary pawl carrier to a starting position and wherein repeated rotational actuation of the ratcheting lock ring serves to maintain tension in a fastening

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.