Systems and methods can include stretching a stud of a hammer assembly by tightening, according to a preset amount, a plurality of fasteners, which can extend from a first end surface and/or a second end surface of a first nut threadedly coupled to the stud, against an upper surface of a body of the hammer assembly. The fasteners and the first nut can provide a clamping load for the stud upon completion of the tightening. The systems and methods can also include, after the stretching, tightening a second nut, which can be threadedly connected to the stud, toward a seat formed in the body of the hammer assembly; and further tightening the second nut, against the seat. The systems and methods can further include transferring the clamping load from the fasteners and first nut to the second nut.

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 hold down system for a building wall comprises a first rigid member and a second rigid member, the second rigid member being vertically spaced apart from the first rigid member, the first rigid member is supported on a horizontal member of a stud wall, the first and second rigid members including first and second openings, respectively; a tie-rod with a lower end portion for being anchored to an anchorage, the tie-rod extending transversely through the first and second openings, the tie-rod dividing the first and second rigid members into a first lateral section on one side of the tie-rod and a second lateral section on a diametrically opposite side of the tie-rod; first support and second support disposed between the first and second rigid members, the first support being disposed in the first lateral section, the second support being disposed in the second lateral section, the tie-rod extending through the first and second rigid members outside of the first support or the second support; and a nut threaded to the tie-rod, the nut exerting pressure on the second rigid member to place the tie rod under tension loading, the tension loading is transferred by the second rigid member to the first and second supports to subject the first and second supports to compression loading, thereby causing the first rigid member to press on the horizontal member of the stud wall via the first and second lateral sections of the first rigid member, thus distributing the compression loading.

An insert nut includes a cylindrical portion into which a bolt is removably insertable. An inner periphery of the cylindrical portion includes a first region, a second region and a third region which are provided in the order named from an upstream side to a downstream side with respect to an insertion direction of the bolt at an inner periphery thereof. The first region and the third region include a female screw portion threadably engageable with the bolt. The second region has a minimum inner diameter larger than D1+2×h1×0.3, where D1 is an inner diameter of the female screw portion in the first region at a screw thread position and h1 is a height of a screw thread of the female screw portion in the first region.

The present invention refers to system for tensioning at least one connecting element fastened to a component to be tightened, The system comprises at least one connecting element tensioning device having 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; at least one electric actuator for rotationally actuating the actuating element; and a control unit (CPU) for actuating the at least one electric actuator.

A clamping device for expanding a threaded bolt is provided with a support pipe supported against an underlay surrounding the threaded bolt. A cylindrical housing arranged in extension of the support pipe has a piston movable in longitudinal direction and connectable to a hydraulic supply. A changeable bushing is axially carried by the piston and is provided with an inner thread and a radially expanded portion. A resilient arrangement is arranged around the bushing and acts axially on the piston. A lid is secured to the housing. The other support of the resilient arrangement is provided on the lower side of the housing. The lid has a lid base member and a closure lid. The lid base member is provided with an opening closable by the closure lid. The radial extent of the opening is greater than the radial extent of the radially expanded portion of the bushing.

A sealing device for a hydraulic assembly wherein hydraulic fluid is contained in working chamber (53) formed between body (52) and thrust member (51) of the assembly. The device comprises annular seal (63) with opposed sealing faces which are urged into sealing engagement between body (52) and thrust member (51) which have convergent sealing faces. The device may also have a pressure relief valve (100) tapped into the over-stroke end of chamber (53) to protect seal (63) from over-stroke damage comprising porous body (101) which allows fluid to bleed from chamber (53) and allows seal (63) to pass the tapping point without obstruction.

The present invention refers to a device for tensioning a connecting element fastened to a component be tightened, comprising a fixation element for holding the connecting element; a support element for supporting the device against the component; and an actuating unit with a fluid chamber for receiving a fluid and a piston which is translationally guided in the fixation element. The actuating unit is configured for manipulating a volume of the fluid chamber by translationally actuating the piston so as to move the fixation element relative to the support element. The piston is coupled to the fixation element by means of at least one ball or roller screw.

A screw tensioning device for tensioning or loosing tensionable screw connections comprises a fixation element to be connected to a screw, a support element moveable relative to the fixation element. The support element is arranged moveable relative to the fixation element to apply tension to or remove tension from the screw. A piston is positioned and movable within the fixation element. A volume containing a hydraulic fluid is defined at least partly by the piston, the fixation element or the support element. The movement of the piston manipulates the volume and thereby moves the fixation element with respect to the support element.

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.