Abstract: A fastening tool includes: a cylindrical rotation guide member extending in one direction and rotatably supported; a holding member having an opening to which a driver bit is detachably inserted, and configured to move in an axis direction along the extension direction of the rotation guide member inside the rotation guide member and to rotate together with the rotation guide member; and a moving member configured to move the holding member in a front and rear direction along the rotation guide member.

Abstract: A torque wrench for multiple bolts or nuts comprises multiple drive spindles that are arranged annularly around a center and are equipped or able to be equipped at the end with respective torque-applying tools, and a ratchet drive, associated with each drive spindle and driven by means of a hydraulic piston drive, for driving the drive spindles. In addition to the ratchet drive, a locking ratchet for locking the drive spindle acts on each drive spindle to keep it from turning back when exercising a return stroke movement of the drive ratchet. The locking ratchets are arranged in a locking bracket, which is penetrated by the drive spindles. The locking bracket has means for loosening the locking ratchets.

Abstract: The hydraulic system according to the invention comprises a hydraulic circuit with a low-pressure region and a high-pressure region; a volume- and/or speed-variable hydraulic machine, which is driven by a first electric motor and has an inlet and an outlet and provides a volume flow of a hydraulic fluid in the high-pressure region of the hydraulic circuit. The hydraulic system according to the invention further comprises at least one movable shaft, which is arranged in the high-pressure region of the hydraulic circuit; at least one valve, which separates the high-pressure region from the low-pressure region; and at least one hydraulic fluid container, which is hydraulically connected to the low-pressure region of the hydraulic circuit.

Abstract: A hydraulically operated handheld device and a method of operating same are provided. The device includes a hydraulic pump, a moving part, a fixed part and a return valve with an associated valve seat. The moving part is moved into a working position due to the buildup of a hydraulic pressure by filling a hydraulic chamber with hydraulic medium from a reservoir with the aid of the hydraulic pump. The moving part can be automatically moved back from the working position into an end position upon reaching a predefined working pressure by opening the return valve. The hydraulic pressure acting upon the return valve is increased by a separately triggerable pressure increase, which results in opening of the return valve, in a hydraulic medium volume located upstream of the return valve in a flow direction of the hydraulic medium during the movement into the end position.

Abstract: A torque wrench for multiple bolts or nuts comprises multiple drive spindles arranged annularly around a center and equipped or able to be equipped at the end with respective torque-applying tools, and a ratchet drive, associated with each drive spindle and driven by a hydraulic piston drive, for driving the drive spindles. The drive spindles are rotatably mounted and held in a drive block and have a drive portion at each end, which protrudes from the drive block. The drive sections of the drive spindles serve to bear the torque-applying tools on one side of the drive block, in which drive block the pistons of the piston drives are routed in cylinder housings, such that said pistons are translationally displaceable in both directions. The piston rods are kinematically connected to the ratchet lever for transferring a forward stroke movement and a return stroke movement to respective ratchet levers with pawls.

Abstract: A clamping device for stretching a threaded bolt by pulling on its threaded end section has a support tube surrounding the threaded end section, a cylinder disposed in extension of the support tube, a piston axially movable therein, a changeover bush to be screwed onto the threaded end section and carried along axially by the piston, a hydraulic device for the piston, and a signal link between hydraulic device and a device for detecting the extent of the thread engagement between the changeover bush and the threaded end section. A contactless measurement of the thread engagement between changeover bush and bolt to be clamped for measuring the thread engagement is provided in that the device for detecting the extent of the thread engagement includes a sensor element fastened on the changeover bush, which is positioned axially opposite the end face of the threaded bolt with axial separation.

Abstract: A tensioning device for stretching a threaded bolt by applying tension to the threaded portion of the threaded bolt has a base and a support tube surrounding the threaded bolt and supported on the base. A cylinder housing is arranged as an axial extension on the support tube. A piston is moveably arranged in the cylinder housing and delimits together with an inner wall of the cylinder housing a hydraulic operating chamber. An interchangeable bush is rotatable relative to the piston and can be entrained axially by the piston. The interchangeable bush has an internal thread to establish a screw connection to the threaded portion. A device for path and/or position detection with first and second interacting elements is provided. The first element is fastened to the at least one piston and faces the cylinder housing. The second element is fastened to the cylinder housing and faces the piston.

Abstract: A reaction arm for use with a torque generating device, the reaction arm including a reaction bar, and a body portion having a first internal diameter, and having formed on an internal surface thereof a female spline having a second internal diameter and a guide bushing having a third internal diameter, the first, second, and third internal diameter being distinctly sized.

Abstract: A quadrilobe connector defined by a cross-sectional shape derived from a square, where each of the corners of the square is replaced with an arc of a circle, and ends of two adjacent arcs meet to form a depression between the arcs. Further, each of the four arcs is equal in radius and intersects tangentially to each other arc.

Abstract: A device for rotation of a torque tong with at least two diametrically opposite circular arc-shaped segments and gripping devices for holding a pipe substantially perpendicularly to the torque tong's radial plane. To each segment and in abutment thereto there is provided at least one elongated flexible drive element operatively connected to support units and devices for movement of the respective drive element so that the torque tong is rotated in the radial plane. Each drive element is attached at first and second ends to respective securing portions and includes an engagement portion in engagement with and/or abutment against a segment. Rotation of the torque tong is implemented by performing a rectilinear movement of a first of said movement elements, and simultaneously implementing a rectilinear movement of the second of said movement elements in the opposite direction to and substantially parallel to the movement of the first movement element.

Abstract: A hydraulic wrench extension includes an input head connected to an output head via a fluid conduit. The input head is adapted to receive an input torque and convert the input torque into hydraulic fluid pressure. The fluid conduit is adapted to communicate the pressurized hydraulic fluid from the input head to the output head. The output head is adapted to convert the hydraulic fluid pressure into torque for applying to a fastener. The hydraulic wrench extension may comprise an articulating linkage adapted to house the fluid conduit and provide a configurable orientation of the wrench extension for traversing obstacles and accessing difficult-to-reach fasteners.

Abstract: A hydraulic wrench for high-torque tightening/loosening which has two separate functions. The first function provides a manual wrench for performing tightening/loosening approximations which is accomplished by blocking of the bearing wrench regarding the a piston, the device becoming rigid as it was one single body. In the second function the hydraulic wrench serves as a tool performing high-torque tightening and loosening.

Abstract: A hydraulic flow sensing apparatus is provided. The apparatus includes: a manifold; a hole in the manifold in fluid communication with a fluid pathway; a poppet valve in the hole in the manifold configured to move when fluid in the pathway flows; and a proximity switch configured to detect movement of the poppet valve. A method of operating a hydraulic circuit may also be provided.

Abstract: Apparatus and methods for threading a nut along a stud or similar elongate member include use of a contact member within a first orifice that engages the nut, and a torque transfer member within a second orifice that engages both the contact member and a power source, such as an air ratchet. Torque from the power source causes movement of the torque transfer member, which in turn causes movement of the contact member, thereby threading or unthreading the nut along the stud or other elongate member. The first orifice includes a through bore for accommodating passage of the elongate member, while the body of the apparatus can include ferromagnetic members for preventing loss of the nut and additional structures for limiting undesired movement of the power source or apparatus through contact.

Abstract: A pneumatic driven ratchet wrench comprises: a wrench housing; a spindle-engaging unit including a ratchet wheel; a rotation-driving unit for driving rotation of the spindle; a direction-driving unit; a reverse gear unit driven by the direction-driving unit to engage the ratchet wheel so as to switch rotational directions of the spindle; a first valve unit operable to permit fluid communication between a first fluid passage and one of a chamber and a second fluid passage while preventing fluid communication between the first fluid passage and the other of the chamber and the second fluid passage; and a second valve unit operable to permit fluid communication between the second fluid passage and a selected one of third and fourth fluid passages.

Abstract: A uniquely designed torque wrench having a torque body, the torque body attached to a drive head, the drive head entering a contracted stated during extension of a rod of a hydraulic cylinder, and entering an expanded state during the retraction of the rod of a hydraulic cylinder.

Abstract: A compact one touch pneumatic wrench includes a cylinder having an improved air passage to achieve one touch function and a housing mad of engineering plastic material. Compared to a conventional pneumatic wrench which needs one hand to hold the handle and the other hand to operate the clockwise/counterclockwise rotation of the motor, the present invention improves the air passage of the cylinder to provide a simple and convenient operation with only one hand, providing a convenient operation and enhancing the work efficiency.

Abstract: A hydraulic press unit has a fixed part and a movable part. The movable part is moved relative to the fixed part by a hydraulic piston and is moved back into a starting position by a return spring. In addition, the return motion is actuatable as a function of a predetermined applied pressure by activation of a return valve. A control valve is provided which, in addition to the return valve, opens a hydraulic-medium outlet when in its open state and has a hydraulic-medium inflow side and a hydraulic-medium outflow side. In order to configure the hydraulic press unit, when the return valve opens, the control valve is acted on by the pressure of the returning hydraulic medium on the inflow and outflow sides, the pressure being lower on the inflow side due to throttling.

Abstract: A pneumatic screw driver includes: a tool body; a nose portion; a main air chamber; a hammering cylinder; a driver bit integrally combined with a hammering piston in the hammering cylinder; an air motor; a valve housing provided in an air passage between the main air chamber and the air motor; a stop valve piston provided in the valve housing; a stop valve stem coaxially provided with the stop valve piston; a timer chamber connected to the hammering cylinder; a first pipeline and a second pipeline respectively formed at upper and lower positions in a lower portion of the stop valve stem; and a upper end proximal portion of a contact member provided slidably in a driving direction. The upper end proximal portion of the contact member is provided engageably with the stop valve stem. The first pipeline and the second pipeline are arranged so as to close the first pipeline after closing the second pipeline by moving the stop valve stem upward from a bottom dead center.

Abstract: A hydraulic torque wrench has a support partially sandwiched between first and second side plates. The support has hoop that extends beyond the edges of the plates so that the hoop has a smaller width than the wrench. An inner surface of the hoop defining a groove that receives a rib of a lever that fits against the hoop. This lever has an internal opening in which a socket disposes. A segment movable segment on the lever has teeth that ratchet with teeth around the socket. As the lever is reciprocated back and forth by an actuator on the wrench, the ratcheting between the lever and socket turn the socket and any nut disposed therein. The arrangement of the hoop, socket, and lever enable the wrench to be used in locations around nuts having tight clearances.

Abstract: Apparatus and methods for removing valve cover components includes a torque transfer tool that mates with an extending portion of the valve cover assembly and has a multi-faceted segment to receive a torque-supplying wrench. A hydraulically-actuated wrench has a head with a multi-faceted portion that engages the corresponding multi-faceted segment of the torque transfer tool. The wrench's hydraulic cylinder rotates the wrench head upon actuation. The multifaceted segments can be splined. Also disclosed is a reaction tube against which the wrench can be braced prior to actuation of the cylinder.

Abstract: A hydraulic wrench for high-torque tightening/loosening which has two separate: the first function provides a manual wrench for performing tightening/loosening approximations; through the blocking of the bearing wrench regarding the piston, the whole set becoming rigid as it was one single body; the second function consists of the hydraulic wrench tool performing high-torque tightening and loosening.

Abstract: A dust suction module includes a plurality of bearing surfaces (2, 2?, 2?) with which the dust suction module (1) is mountable on an associated hand-held power tool (3), an air filter (4), a rotatable suction wheel (5), a plurality of opening outwardly, air discharge openings (6), and a plurality of opening outwardly, auxiliary discharge openings (7) formed in at least one of the plurality of bearing surfaces (2).

Abstract: Centrally mounted in a strain decoupling fashion on a hydraulic torque wrench is a hose connect swivel. A base ring of the swivel features a first fluid transmitting joint that is fluid transmitting connected with axial studs extending from the base ring into mating holes in the torque wrench housing. The base ring is radially spaced apart and surrounding a central housing portion of the torque wrench. The radial spacing provides for a strain and deformation decoupling of the base ring from the torque wrench housing such that leakage in the fluid first transmitting joint is prevented. A second fluid transmitting joint provides together with the perpendicular first fluid transmitting joint for a three dimensional orienting of the hose connect terminal around the torque wrench housing while providing access to the piston side peripheral end of the torque wrench housing for an eventual reaction arm.

Abstract: A system, apparatus, and method for installing fasteners are disclosed involving a fastener installation tool and a socket assembly. The fastener installation tool comprises a tool component and a gear head. The gear head comprises a lever, a retaining slide, a retaining slide housing, and at least one gear. The socket assembly comprises a socket, a hex key, and a hex key retainer. An end of the drive shaft of the socket has an annular groove around the circumference of the exterior surface of the drive shaft. When the retaining slide is slid into a locked position, the retaining slide engages the annular groove of the drive shaft of the socket, thereby attaching the drive shaft of the socket to the gear head of the fastener installation tool. A socket gear of the gear head matingly engages the drive shaft of the socket to rotate the socket.

Abstract: A ratchet wrench has a handle and a ratchet housing that both extend along a first axis. A drive body is connected for rotation relative to the ratchet housing about a second axis, perpendicular to the first axis. A yoke substantially encircles the body and is connected to the ratchet housing and a direction selector is coupled to the drive body and extends along the second axis. The direction selector is rotatable about the second axis with respect to the drive body between a first position, in which the yoke is fixed for counterclockwise rotation with the drive body about the second axis, and a second position, in which the yoke is fixed for clockwise rotation with the drive body about the second axis. A direction actuator is connected to the direction selector for rotation about the first axis to move the direction selector between the first and second positions.

Abstract: A pneumatic fastener driving tool is configured to drive a threaded fastener using both linear and rotational motion. The tool allows a fastener to first be driven linearly, without rotation, through a surface material and into a substrate material, preferably to a depth that causes the fastener to at least pierce the substrate material. The tool then rotates the threaded fastener and causes it to fully engage the substrate material, thereby fastening the surface material to the substrate material. The tool has sufficient linear force to drive a fastener into relatively hard substrate materials, such as steel studs, and has a stationary air motor assembly to reduce recoil generated during the driving process. The tool further comprises a gear reducer assembly that uses a compound planetary gear in order to reduce the overall length of the tool.

Abstract: A rapid-action connection element for a compressed air hose (3) includes a filter (5) located in the discharge casing (4) for sealing a flow cross-section, a flow-through pressure piston (7) extending, at least partially into the discharge casing (4) and displaceable, within limits between outward position remote from the filter (5) in which the pressure piston (7) is sealed with respect to the discharge casing (4), and an inward position adjacent to the filter (5) in which the pressure piston (7) is open with respect to the discharge casing (4) for flow therebetween, and a flow-through rapid-action coupling member (6a) connected with the pressure piston (7).

Abstract: A system, apparatus, and method for installing fasteners are disclosed involving a fastener installation tool and a socket assembly. The fastener installation tool comprises a tool component and a gear head. The gear head comprises a lever, a retaining slide, a retaining slide housing, and at least one gear. The socket assembly comprises a socket, a hex key, and a hex key retainer. An end of the drive shaft of the socket has an annular groove around the circumference of the exterior surface of the drive shaft. When the retaining slide is slid into a locked position, the retaining slide engages the annular groove of the drive shaft of the socket, thereby attaching the drive shaft of the socket to the gear head of the fastener installation tool. A socket gear of the gear head matingly engages the drive shaft of the socket to rotate the socket.

Abstract: A power driven tool for rotating a mechanical fastener including a housing with a motor positioned in the housing. The motor includes a drive shaft that rotates relative to the housing. An impact mechanism in the housing is operatively connected to the motor drive shaft. The impact mechanism has a base, an output and a cam. The output and cam are rotatably mounted on the base. A pair of hammers are pivotally mounted on the base and selectively positioned by the cam. The cam biases the hammers to intermittently impact the output. A ratchet head assembly is operatively connected to the output of the impact mechanism. The ratchet head assembly includes an output member rotatably mounted on the housing to rotate the mechanical fastener. The assembly also includes a ratchet operable to limit rotation of the output member in a selected direction.

Abstract: A pneumatic screw driver includes: a tool body; a nose portion; a main air chamber; a hammering cylinder; a driver bit integrally combined with a hammering piston in the hammering cylinder; an air motor; a valve housing provided in an air passage between the main air chamber and the air motor; a stop valve piston provided in the valve housing; a stop valve stem coaxially provided with the stop valve piston; a timer chamber connected to the hammering cylinder; a first pipeline and a second pipeline respectively formed at upper and lower positions in a lower portion of the stop valve stem; and a upper end proximal portion of a contact member provided slidably in a driving direction. The upper end proximal portion of the contact member is provided engageably with the stop valve stem. The first pipeline and the second pipeline are arranged so as to close the first pipeline after closing the second pipeline by moving the stop valve stem upward from a bottom dead center.

Abstract: The invention relates to a tool for loosening or tightening bolts on subsea structures. The tool grasps a portion of the structure and, using hydraulic wrenches, tightens or loosens bolts located on the structure.

Abstract: A hand tool device incorporates a fluid operated mechanism actuable by a plunger pressurizing a reservoir to force fluid past a resiliently biased valve to a fluid filled cylinder accommodating a piston carrying a contact member for clamping a work piece in the manner of an adjustable wrench or pliers. Continued operation of the plunger increases the pressure applied to the work piece.

Abstract: An electrohydraulic unit assembly for a motor vehicle comprising a receiving body defining a sealing face and at least two connectors fastened to the receiving body of the unit, oriented substantially parallel one to another and separated by a defined distance from one another. Each connector is configured for connecting a fluid conduit to the unit. Each connector includes a screw fitting for fastening the respective hydraulic connection to the receiving body of the unit such that a sealing face of the screw fitting or a sealing face of the fluid conduit is seated on the sealing face of the receiving body. Each screw fitting is rotatably connected to the body and includes two spanner flat portions having different spanner widths.

Abstract: A fastener-driving tool includes a combustion power source configured for driving a driver blade linearly towards a workpiece, and an electrical power source associated with the combustion power source for rotationally driving the driver blade upon completion of the linear travel, both power sources being disposed in the tool.

Abstract: A method for measuring applied torque of a oilfield tubular torque wrench, the oilfield torque wrench being operable to torque a tubular about an axis of rotation and the oilfield torque wrench including a lower tong including a recess through which the axis of rotation passes during operation; an upper tong including a recess, the upper tong being mounted above the lower tong with the recess of the upper tong positioned above the recess of the lower tong so that the axis of rotation passes therethrough; pipe gripping dies in the recesses of the upper tong and the lower tong; a swivel bearing between the upper tong and the lower tong permitting the upper tong and the lower tong to swivel relative to each other while the recesses remain positioned with the axis of rotation passing therethrough; a drive system connected between the upper tong and the lower tong, the drive system being operable to generate a force vector to drive the upper tong and lower tong to swivel on the swivel bearing, the method comprisin

Abstract: A compact, hydraulically operated tool for use in hard-to-reach or compact spaces.

Abstract: An improved pneumatic tool design includes pneumatic motor chamber that houses a turbine. An air path directs compressed air into the pneumatic motor chamber. The air path includes an air inlet chamber that at least partially surrounds the pneumatic motor chamber. The air path also includes a motor inlet disposed in one side wall (e.g., the top wall) of the pneumatic motor chamber forward of the rear end plate thereof. The air path further includes at least one exhaust port disposed in an opposite side wall (e.g., the bottom wall) of the pneumatic motor chamber. A high-pressure seal, such as an o-ring, surrounds the pneumatic motor chamber and isolates the motor inlet, which is thus at a rear outer portion of the pneumatic motor chamber, from a forward outer portion of the pneumatic motor chamber.

Abstract: Method and apparatus to make-up or break-out a threaded tubular connection using an integrated power tong and back-up tong (10). The power tong (20) may be disabled upon sensing a predetermined threshold amount of displacement of at least a portion of a back-up tong (14). The sensed displacement indicates that the back-up tong (14) is slipping, and power tong (20) rotation may be disabled to prevent damage to the pipe string (16) or surrounding equipment. A slippage sensor (40) may be disposed to sense displacement of at least a portion of the back-up tong (14) relative to a supporting frame (12). In one embodiment, the slippage sensor (40) may be operatively coupled to a valve (50) disposed in communication with a fluid line (46) supplying power fluid to the power tong (20). The power tong (20) may be disabled by impairing flow to the power tong (20) upon sensing a predetermined displacement of the back-up tong (14).

Abstract: The invention relates to a hydraulic power wrench comprising a ratchet lever (16) driven by a hydraulic cylinder. According to the invention, said power wrench is provided with a friction brake (20) which operates continuously between the housing (10) and the output shaft (14). In this way, reversed rotations of the output shaft following the individual working strokes are avoided.

Abstract: A torque tool for tightening or loosening connections has a driving element engageable with a turnable part of the connection for turning the turnable part of the connection for tightening or loosening the connection and turnable about an axis, and a power drive configured for acting on the driving element such that the drive acts on the driving element to turn the driving element and thereby to turn the turnable part of the connection over a partial stroke and a space is formed between the drive and the driving element, and the drive is then displaced over the space toward the driving element to act again on the driving element to turn the driving element and thereby to further turn the turnable part of the connection over a further partial stroke.

Abstract: The present invention relates to a fastening member fastening apparatus for positioning and fastening a hexagon head bolt (2) with respect to a nut (7) with an opening (7a). The fastening member fastening apparatus comprises a rotary axle body (1) being rotated by a drive source, a forwardly and backwardly movable socket (3) being connected with a tip end of the rotary axle body (1) and fitting thereon the hexagon head bolt (2), and a guide mechanism (5) having triple claw members (4) which are operated to open and close in accordance with the forward and backward movement of the socket (3). A tip end of the guide mechanism (5) in a closed state is inserted into the opening (7a) of the nut (7) so as to position and fasten the hexagon head bolt (2) with respect to the nut (7).

Abstract: The piston 32 and cylinder 30 of a torque wrench 18 are provided with pressurised fluid from a source 12 through an advance port 16, or from a pump 42 through a return port 38. The source 12 includes a large piston 26 driven from the pump 42 during the advance stroke, and a small piston 22 driving fluid to the advance port 46, or receiving fluid returned from the port 16, during the return stroke. Accordingly, the pistons 22 and 32 form a closed system for fluid moving between the cylinder 24 and the cylinder 30. The pistons 22, 26 are connected by a shaft 68 so that relatively low pressure applied to the piston 26 results in high pressure fluid delivered to the advance port 16. Consequently, a low pressure pump 42 can be used to provide high pressure drive via the source 12, or a low pressure return stroke via the return port 38.

Abstract: A hand tool device incorporates a fluid operated mechanism actuable by a plunger pressurizing a reservoir to force fluid past a resiliently biased valve to a fluid filled cylinder accommodating a piston carrying a contact member for clamping a work piece in the manner of an adjustable wrench or pliers. Continued operation of the plunger increases the pressure applied to the work piece.

Abstract: A power tong (1) device, in which the power tong (1) includes two housing halves (2), pivotable relative to each other, the housing halves (2) being arranged to be pivoted between a closed, active position and an open, inactive position, and in which a radially divided drive ring (6, 8), which is provided with hydraulically activated clamping dies (14) directed towards the centre axis (10) of the power tong (1), is placed in the housing halves, the drive ring (6, 8) being supported and connected to a driving motor (12) for the rotation of the drive ring (6, 8) about said axis (10), the drive ring (6, 8) being provided with at least one locking means (16) which is arranged to interconnect the parts of the drive ring (6, 8) in a releasable manner.

Abstract: An apparatus for fastening a washered bolt with a flat washer passed therethrough, to a fastening object. Air discharged from an air blow nozzle is blown into a space between a head of the bolt accommodated in a socket and the flat washer. Foreign matter will be prevented from adhering to the flat washer and the bolt head.

Abstract: An apparatus to be used in a gripping assembly for gripping a cylindrical member is disclosed. The apparatus includes a jaw body, a gripping insert, and a rotatable camming member disposed between the jaw body and gripping insert. The rotatable camming member rotates in response to the applied clamping and rotational forces of the gripping assembly and operates to intensify the force provided by the jaw to the gripping insert which is engaged with a cylindrical member.

Abstract: The present invention aims to provide a screw fastening machine for reliably switching and changing a driving force transmitting path with the seating on a work as a reference. According to the screw fastening machine in which a first pulley is connected to a first driving mechanism for applying high speed low torque drive to a drive shaft, a second pulley is fixed in an integrally rotatable manner to a transmission shaft for connecting the drive shaft, and an endless belt is interposed between the pulleys to obtain a configuration for high speed low torque drive, a second driving mechanism for low speed high torque drive is arranged on an extension of the transmission shaft, and the second driving mechanism performs the drive until a final fastening torque is reached when a screw component is seated on the work and the stall state is achieved, the final fastening torque is always reliably obtained and the work time is reduced without waste.

Abstract: A hydraulic threaded bolt clamping device for tightening and releasing threaded bolts has a pressure medium supply connected to a pressure medium connector. A cylinder rests against a machine part that is to be clamped and a periodically pressure-loaded piston is guided seal-tightly in the cylinder and rests against a threaded bushing screwed onto the threaded bolt. A control device actuates the pressure medium supply for supplying pressure medium to the bolt clamping device. After a nominal value corresponding to a nominal prestressing force has been reached the pressure medium supply is switched off. The nominal screw prestressing force or a corresponding nominal pressure of the pressure medium supply is preset by an input device. A measuring device measures relative displacement of the threaded end of the bolt relative to the cylinder. An evaluation device determines residual actual screw prestress after pressure relief of the bolt clamping device.

Abstract: The non-axial force exerted on a pneumatic tool by a non-axial air supply is balanced to allow for uniformly radially distributed compliance forces on the tool. An annular air ring is disposed around the pneumatic tool, covering an air inlet port. Air is supplied by any route to a first air passage that supplies the air to the interior of the annular air ring, exerting a force on the annular air ring. Air flows in the annular space of the air ring, entering the tool air inlet port to drive the pneumatic tool. One or more second air passages are connected to the annular air ring in an even radial distribution. Each second air passage is connected to the air source, or terminates in an air blockage, creating a column of pressurized air that exerts a force on the annular air ring equal to the first air passage. The forces exerted on the air ring are thus balanced with respect to the axis of the tool.