The present invention refers to a device for tensioning a connecting element fastened to a component to be tightened, which comprises a fixation element for receiving and 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. Further, the device comprises a guiding unit for locking a relative rotational movement between the piston and the fixation element, wherein the guiding unit is arranged outside of the fluid chamber.

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 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 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.

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+2h10.3, 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.

A pressing device for a machine tool for processing or machining workpieces made of wood or plastics is provided with at least one support with a counter wedge surface. At least one pressing element is fastened to the at least one support. At least one wedge clamping device is provided that has at least one wedge pressure member with a first wedge surface that is resting on the counter wedge surface of the at least one support. The at least one wedge clamping device also has at least one adjusting element acting on the at least one wedge pressure member. The at least one wedge clamping device clamps the at least one pressing element on the at least one support. A machine tool with such a pressing device is provided.

A lock nut system includes a nut threadably engageable with a shaft and a keeper having a projection configured to fit within a slot of the shaft to engage the shaft. A retaining member is formed separate from the keeper and the nut. The retaining member is receivable within a slot of the nut to engage the nut. A portion of the retaining member engages the keeper by extending into a keeper cavity within the keeper. The nut is lockable onto the shaft when the projection of the keeper is fit within the slot and the keeper is abutted and supported by an inner shoulder of the nut and the retaining member engages the nut and the portion of the retaining member extends into the cavity within the keeper.

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 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 pretensioning element pressure screw (11) having a shank (12) which has a first end (13) and a second end (14), opposite the first end (13). Starting from the first end (13), a threaded portion (16), having an outer diameter (D), is formed adjacent a threadless shank portion (21), having an outer diameter (dg). The threadless shank portion (21) extends to the second end (14) of the shank (12). An engagement mechanism (26) for a tool is arranged at the first end (13) of the shank (12). The outer diameter (dg) of the threadless shank portion (21) corresponds to 1.0 times the outer diameter (D) of the threaded portion (16). A pretensioning element and a pretensioning screw body element having a plurality of such pretensioning element pressure screws (11) is also disclosed.