A tensioner, typically hydraulic, for threaded members, the tensioner comprising: a base (4) and a piston (6) defining a pressure space (13) therebetween, the base (4) and piston (6) being arranged to be urged apart along an axis (17) upon introduction of a fluid into the pressure space (13); and a thread-engaging member (7), comprising a body portion (8) of the form of a sleeve and having a threaded interior (30) for engagement with a threaded member (2) and a piston engaging portion (9) carrying a protrusion; in which the piston (6) bears against the protrusion such that the piston (6) exerts a force on the protrusion when urged apart from the base (4) by the introduction of fluid into the pressure space (13); the tensioner further comprising a displacement sensor arranged to determining the relative position of the body portion of the thread-engaging member and the base, the displacement sensor comprising a first part (12) carried on the base (4) and a second part (11) carried on the body portion (8); typically the displacement sensor is a magnetic encoder.

A tool assembly for mounting a tailgate to a car body is provided. The tool assembly includes a bracket adapted to engage with an overhead structure and a frame movably coupled to the bracket and configured to move in a vertical direction relative to the bracket. The tool assembly also includes a linkage mechanism movably coupling the frame with the bracket and configured to maintain the frame parallel to the bracket during the vertical movement of the frame. Further, a pair of torque guns is coupled to the frame and is configured to hold a pair of fasteners. The pair of torque guns engages and tightens the pair of fasteners to the car body and a hinge attached to the tailgate.

A multi jack tensioner including: a body portion formed to engage an elongate fastening member or integrally formed therewith; a load bearing member for applying force to a workpiece to be fastened and arranged for location about said fastening member adjacent the body portion; a pressure chamber between the load bearing member and the body portion arranged to displace the body portion from the load bearing member in response to hydraulic pressure; and a plurality of jack bolts extending between the body portion and the load bearing member for further displacing the body portion from the load bearing member; wherein application of hydraulic pressure to the hydraulic chamber displaces the body portion from the load bearing member for tensioning said fastening member and whereby subsequent tensioning of the fastening member is applied by operation of the jack bolts.

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 device for tightening a screw connection on a flange connection is provided with a tool carrier movable along the flange connection and provided with a traction drive. A tool is arranged on the tool carrier for tightening the screw connection and rotating the nut relative to the flange connection. A control unit is provided for moving the tool carrier in longitudinal direction of the tool carrier into a working position by traction drive control signals. In the working position, the tool is opposite the screw connection to be tightened. The control unit performs, by tool control signals, tightening of the screw connection and rotating of the nut. The control unit has a travel control module with travel controller for moving the tool carrier into the working position. The travel controller stops the traction drive after a predefined travel length has been reached that is a target variable.

A bolt tensioning assembly has a bolt with a first end portion and a second end portion at an opposite side of the bolt. The first end portion has an enlarged diameter to form a counter-pressure surface facing the second end portion. The first end portion has external threads to receive a lock nut. A hydraulic bolt tensioning device is for tensioning of the bolt. The hydraulic bolt tensioning device is arranged for enclosing a portion of the bolt such that it abuts the counter pressure surface. A lock nut is arranged on the first end portion of the bolt. The hydraulic bolt tensioning device and lock nut are dimensioned such that upon tightening of the lock nut, the lock nut will tighten against a portion of the hydraulic bolt tensioning device.

A tensioning device for elongating a screw assembly, provided with threaded bolt and threaded nut supported on a fixed substructure, by applying a traction force to a free threaded end of the threaded bolt has a cylinder housing with internal wall and a piston movable in the cylinder housing in longitudinal piston direction. The piston together with the internal wall delimits a hydraulic operating space. A replaceable bush entrained by the piston in the longitudinal piston direction has a thread with which the bush can be screwed to the threaded bolt. A support tube is disposed on the cylinder housing, is supported on the fixed substructure, and surrounds the threaded nut. A lock bar is disposed on the support tube and has a lock-bar face facing the piston. The lock-bar face bears on a blocking face of the threaded nut that faces away from the piston.

A hydraulic tensioning and release tool for an expansion fastener of a type having an elongate member with a tapered portion for fastening a workpiece. The tool includes a sleeve for placement about the tapered portion; a cylinder(s) including a cylinder for generating compressive force against the workpiece; a release piston for displacing the sleeve and a tension piston for coupling to elongate member. The tension piston and the cylinder(s) defining a tension chamber and the release piston. One of cylinder(s) defines at least one release chamber. Hydraulic ports are in fluid communication with the tension chamber and the release chamber for application of hydraulic pressure to displace the tension piston and the release piston for respectively tensioning the elongate member and for releasing the sleeve from the tapered portion. A tension retaining arrangement retains the elongate member in tension subsequent to removal of hydraulic pressure from the tensioning chamber.

A method for erecting a wind turbine tower is disclosed. A tower section (8) comprising a lower flange (9) and an upper flange (10), and a plurality of stud bolts (6) and nuts (7) are provided. The tower section (8) is oriented in an upright position with the lower flange (9) below the upper flange (10), and stud bolts (6) are positioned in bolt holes (12) in the lower flange (9) with nuts (7) arranged on an upper side of the lower flange (9). The tower section (8) is lifted to a mounting position on top of another tower section (13), and a flange combination is formed by aligning the bolt holes (12) formed in the lower flange (9) of the tower section (8) with bolt holes (15) formed in an upper flange (14) of the other tower section (13), while advancing the stud bolts (6) through the bolt holes (12, 15). The invention further provides a socket tool (16) for screwing nuts (7) onto stud bolts (6) in a manner which positions the stud bolts (6) correctly with respect to a flange (9).

A locking bolt assembly (1) for securing a mantle (40) to a head assembly (60) of a crushing device comprising: a locking bolt (10) having a head portion (10a) and a thread portion (10b); a re-useable thrust plate (30) disposed between the head portion (10a) and a top surface portion (42) of the mantle (40); one or more fasteners (20) for connecting the locking bolt (10) to the re-useable thrust plate (30); and one or more permanent jacking screws (34) for forcing the locking bolt (10) up and the thrust plate (30) down onto the top surface portion (42) of the mantle (40) so that the mantle (40) is secured on the head assembly (60). Also provided is a method for securing a mantle (40) to a head assembly (60) of a crushing device using the locking bolt assembly (1).