A system for tensioning a stud that projects from a structural member is provided. The system comprises a safety guard including a guard housing and a hydraulic interlock assembly, and a tensioning system coupled with a first end of the stud. The guard housing surrounds at least a portion of the tensioning system and is coupled with a second end of the stud and the hydraulic interlock assembly. The hydraulic interlock assembly is coupled with the guard housing and the tensioning system. The hydraulic interlock assembly provides fluid communication of a hydraulic fluid from a hydraulic source to the tensioning system to tension the stud.

The invention relates to a gyratory crusher for comminuting material to be crushed, comprising a crusher housing, in which a crusher shaft is arranged, said shaft being held in the crusher housing so that it can tumble about a vertical axis. To accommodate the crusher shaft, the crusher is provided with a cross member which extends diametrically across the crusher housing and the cross member ends of which are connected to the crusher housing. According to the invention, the connection of the cross member ends to the crusher housing has at least one hydraulic 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.

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.

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 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.

The present invention refers to a device for tensioning a connecting element fastened to a component to 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.

Two or more vehicle components can be operatively connected with one or more fasteners configured to provide selectively variable dampening characteristics. The fastener can include a dampening unit configured to provide different dampening characteristics based on a torque applied to the fastener. In one or more arrangements, the dampening unit can provide different dampening characteristics based on an amount of compression the dampening unit is under. Target dampening characteristics between two or more components can be determined. A torque can be determined and applied to the fastener based on the target dampening characteristics. The torque can cause the dampening unit of the fastener to compress and provide the target dampening characteristics between the components.

A fastener assembly includes a stud, a threaded sleeve, and a compression spring. The stud includes a shaft with a first head at one end and a second head at an opposite end of the shaft, both heads with opposing bearing surfaces. The threaded sleeve is disposed about the shaft. The threaded sleeve includes external threads and a tubular interior with an inwardly projected shoulder. The compression spring is disposed about the shaft inside the threaded sleeve, with a first end bearing against a shoulder of the threaded sleeve and a second end bearing against a bearing surface of the second head. The spring urges the sleeve against the bearing surface of the first head. The assembly can maintain a preload between two components while allowing the components to be separated, and can also be used as a pressure limiter.

A tensioning device for a thread end portion of a bolt has a cylindrical housing and a piston, moveable in longitudinal direction therein and connectable to a hydraulic supply. An interchangeable sleeve extends centrally through the piston. At its end it has an internal thread with engagement length to be screwed onto the thread end portion. The sleeve has a radially expanded portion carried axially by a carrier face of the piston. In order to prevent the sleeve from prematurely contacting the threaded bolt when mounting the bolt tensioning cylinder and prevent damage to the threads, the sleeve is moveable longitudinally relative to the piston. The longitudinal sleeve travel is defined by the carrier face as first longitudinal stop and by a second longitudinal stop. The longitudinal sleeve travel is at least equal to, preferably greater, than the engagement length of the internal thread of the sleeve.