Abstract: A fastener assembly may comprise a housing defining a first cavity and a second cavity. A first threaded member and a second threaded member may be located within the housing. A first biasing member may be coupled to the first threaded member. A second biasing member may be coupled to the second threaded member.

Abstract: A concrete anchor assembly includes a housing including a lower opening and a side wall; a flange portion extending from the housing; a ramp surface extending upwardly around the lower opening; a split body disposed over the lower opening, the split body including a bottom surface engaging the ramp surface, the split body including a threaded opening. The housing includes a gap between the split body and the side wall. A compressed spring forces the split body toward a bottom of the ramp surface.

Abstract: The invention relates to a mounting device for fastening a toilet seat set to a toilet bowl in a reversibly releasable manner, comprising a connecting segment which can be connected to the toilet seat set in a stationary manner, and a rod segment, which is arranged on the connecting segment and which can be fed at least partially through a mounting opening of the toilet bowl. Furthermore, the mounting device has a deformable blocking part, which is fastened to the rod segment (12) at a distance from the connecting segment, wherein the connecting segment and the blocking part can be arranged on opposite sides of the mounting opening when the rod segment is at least partially fed through the mounting opening of the toilet bowl.

Abstract: A concrete anchor assembly includes a housing having a top opening; the housing including a bottom wall with a bottom opening; the bottom wall including a ramp surface extending upwardly and away from the bottom opening; a split nut disposed on the bottom wall and over the bottom opening; and a spring biased to force the split nut toward a bottom of the ramp surface.

Abstract: A remotely deflectable electrophysiology/ablation catheter of the type intended for placing into an interior passage of the heart. The distal end of the catheter has a pair of tension/compression members each with a flattened end portion connected to the distal electrode and extending through the catheter casing and attached to an actuator for effecting the tension/compression thereon for remotely curling the distal end of the catheter. Spaced ring electrodes are provided adjacent the distal electrode. A permanent bend is pre-formed in the casing and tension/compression members adjacent the ring electrodes about an axis perpendicular to the elongated tension/compression members. Movement of the remote actuator causes the distal portion of the catheter to curl into a lariat in a plane perpendicular to the axis along the elongated catheter casing, thus permitting electrical mapping or ablation with the distal and/or ring electrodes.

Abstract: A device for securing threaded rod can include a housing and a threaded rod locking mechanism. The housing can include a rod locking body with a tapered bore, and a housing extension extending from an end of the rod locking body. The threaded rod locking mechanism can include two plunger pieces, each of which are movable within the tapered bore and include a respective threaded inner surface and a respective sloped outer surface that can engage the tapered bore. The threaded rod locking mechanism can also include a spring disposed within the tapered bore to bias the plunger pieces towards a narrow end of the tapered bore. The plunger pieces can be urged towards each other and towards an axis of the tapered bore by contact between the outer surfaces of the plunger pieces and an internal surface of the tapered bore.

Abstract: A fastener system is provided. The fastener system includes a pair of nuts having a beveled end and opposed flats, a nut housing having a cavity, the cavity including an end wall with an aperture and a tapered interior portion to engage the beveled end, and opposing internal flats to engage the nut flats, a resilient member to urge the beveled ends against the tapered portion; and retaining element. The nuts may include tapered thread edges to accommodate damaged male threads, or cutting thread edges to repair damaged male threads.

Abstract: A nut main body has a slanted hole with a smaller inner end portion having a plurality of stepped portions of differing height. This gives the slanted hole a differing depth relative to a large-diameter end portion of the slanted hole at a plurality of locations about a circumference of the slanted hole. A plurality of nut segments are slidable within the slanted hole and come into contact with at least one of the stepped portions. The nut segments have screw threads at an inner wall surface. A washer is provided at a large-diameter side of the plurality of nut segments. A bias spring is attached within the nut main body so as to urge the plurality of nut segments towards the small-diameter side of the nut main body with the washer therebetween. A stopper piece holds the bias spring within the nut main body.

Abstract: The present invention relates to ratcheting thread clamping devices and the use of multiple interleaved thread structures on one or more of the segments of the ratcheting device. It is shown how the use of such multiple threads reduces locking distance when the ratcheting device is moved in the ratcheting direction along a single-threaded rod, that is, reduced locking distance is achieved with an improved thread clamping device without the necessity of any changes to the threaded rod to which the device clamps. Multiple thread structures thus reduce locking distance in prior art devices typically having frustoconical segment surfaces as well as in more recent devices having nut segments with planar surfaces.

Abstract: A ratcheting take-up device that compensates for imperfect alignment in a tie rod continuity system in the frame of a building wall. The upper ends of the tie rods are tightly clamped within the take-up device by domed segments inserted in a bowl-shaped housing. The segments are also forced together by a compression member in the housing. The domed shape of the segments and the bowl shape of the housing cooperate so that the segments can rotate in any direction to accommodate tie rods that are not perfectly vertical, without a corresponding loss of strength in the connection.

Abstract: The present invention relates to a thread clamping device including a plurality of movable nut segments around a threaded rod, and spring members flexibly holding the segments against the rod. The thread clamping device has a structure adapted to accommodate substantially planar outer surfaces of the segments engaging planar surfaces of the end housing of the device, leading to a more robust device and improved performance. Such a thread clamping device can advantageously be used as a component of a self-adjusting shrinkage compensation device, a coupler for threaded rods, hold-downs, among other uses. Various embodiments of the thread clamping device include a multi nut configuration, a quick release, and including mechanical or magnetic clip attachments.

Abstract: The invention provides a split nut connector in which spaced apart nut sections enable the connector to slide over a threaded battery terminal post until contact is made with the battery cable lug and the threaded nut sections are pushed into engagement with the threaded battery terminal post enabling effective tightening of the nut with a minimal amount of rotation in the fastening direction.

Abstract: The present device relates to a thread clamping device including a plurality of movable segments with threaded inner surfaces suitable for engaging a threaded rod and including a strain gauge therein for measuring the actual strain on the device, in contrast to conventional thread clamping devices restricted to measuring the torque applied during installation, not the actual strain experienced during service. In addition to measuring the actual strain experienced by the thread clamping device, some embodiments of the present invention also relate to a transmitter for transmitting to a remote receiving station the actual strain measured, typically including a suitable identification code for determining which device is transmitting.

Abstract: A nut assembly comprises a capture nut having a smooth bore adapted to fit around the threads of a threaded member such as a bolt or a threaded rod. The capture nut includes a tapered bowl which defines a hexagon in cross section, for example. The nut assembly further includes a split nut having a surface which snugly mates with the tapered bowl of the capture nut. The split nut engages the threads of the threaded member, but only after the split nut is brought into close proximity to the capture nut, thereby avoiding the need to thread the nut assembly the entire length of the threads of the threaded member. The split nut may be formed to two separable pieces, or it may be formed of two integral halves joined together by a thin membrane.

Abstract: A thread clamping device is described including a plurality of movable nut segments around a threaded rod, and spring members flexibly holding the segments against the rod. Smaller locking distances are shown to result by using at least one double-threaded segment as a component of the thread clamping device. Such a thread clamping device can advantageously be used as a component of a self-adjusting shrinkage compensation device, a coupler for threaded rods, hold-downs, among other uses.

Abstract: The invention relates in first instance to a nut having a first part (11) which has a first through opening (Of), and having a second part (12) which has a opening (O2) having an opening contour, the parts (11, 12) being connected so as to be rotatable about a rotational axis (A) which passes through the openings (O1, O2), and the openings (O1, O2) being aligned with one another, in addition, the first opening (O1) on its inner face having a profile which extends in the peripheral direction and which is interrupted in the peripheral direction. In order to provide a nut which is quickly mountable on a threaded bolt, and which has a simple design that allows greater security against the nut coming off the threaded bolt, it is proposed that the opening contour of the second opening is non-circular. The invention further relates to a combination of a bolt (4) having a cross-sectional area with a nut (10).

Abstract: A spindle nut assembly includes inner and outer nuts having corresponding beveled surfaces. The inner nut is tightly threaded onto an end of a spindle and is positioned to achieve a desired endplay setting. The outer nut contacts the inner nut at an oblique angle via the beveled surfaces, which squeezes the inner nut more tightly onto the spindle while still maintaining the desired endplay setting.

Abstract: A separation fastener assembly includes a housing defining a cavity. A frangible nut is disposed in the cavity. The nut includes a plurality of nut segments. The one-piece frangible nut greatly reduces existing assembly problems and difficulties. Adjacent nut segments are interconnected at fracture lines. A bolt has an end coupled to the nut. A movable element is disposed in the housing and movable from a first position to a second position. In the first position, the nut segments are restrained from radial expansion. In the second position the nut segments are permitted to radially expand for releasing the fastener assembly.

Abstract: The present invention relates to a thread clamping device including a plurality of movable nut segments around a threaded rod, and spring members flexibly holding the segments against the rod. The thread clamping device has a structure adapted to accommodate substantially planar outer surfaces of the segments engaging planar surfaces of the end housing of the device, leading to a more robust device and improved performance. Such a thread clamping device can advantageously be used as a component of a self-adjusting shrinkage compensation device, a coupler for threaded rods, hold-downs, among other uses. Various embodiments of the thread clamping device include a multi nut configuration, a quick release, and including mechanical or magnetic clip attachments.

Abstract: The present invention relates to a thread clamping device including a plurality of movable nut segments around a threaded rod, and spring members flexibly holding the segments against the rod. The thread clamping device has a structure adapted to accommodate substantially planar outer surfaces of the segments engaging planar surfaces of the end housing of the device, leading to a more robust device and improved performance. Such a thread clamping device can advantageously be used as a component of a self-adjusting shrinkage compensation device, a coupler for threaded rods, hold-downs, among other uses. Various embodiments of the thread clamping device include a multi nut configuration, a quick release, and including mechanical or magnetic clip attachments.

Abstract: A connecting arrangement is provided. The connecting arrangement includes a bolt with a fastening portion at one end thereof, which has one or more grooves; a cotter having a conical shape and one or more convex cuts on the inner side of the cotter adapted for fitting with the one or more grooves of the fastening portion of the bolt; two support blocks, each having a thread on the outer side, wherein at least one of them is on the inner side adapted for fitting to the conical shape of the cotter; and a fastener having a thread on the inner side, wherein the fastener is adapted for being screwed on the support blocks.

Abstract: A nut assembly for quick adjustment of axial position relative to a threaded shaft. The nut is formed in two, physically separate sections, each having a surface portion with threads for mating engagement with the shaft. Each nut section is pivotally mounted to a bushing which surrounds the threaded shaft for movement of the nut threads into and out of engagement with the shaft threads. The sections are moved about their pivotal mountings by movement of a second bushing axially with respect to the first bushing through cooperative conical surfaces on the second bushing and on each of the nut sections.

Abstract: A retaining device for attachment to a screw contains a hollow base element for receiving a clamping part. The hollow base element has a floor having a hole, and an inner surface of the base element on the floor area of the retaining device is implemented as conical to contact the outer surface of the conical body of the clamping part. The clamping part can be moved downward in the direction of the floor by rotating the retaining device around its own axis and biting into a screw which is inserted through the hole and runs through the opening of the clamping part.

Abstract: A threaded fastener includes an outer body defining a cavity and a central axis extending through the cavity, and a plurality of threaded segments positioned substantially within the cavity. The plurality of threaded segments is movable relative to the outer body generally toward and away from the central axis. The threaded fastener also includes a cap positioned at least partially within the cavity to secure the plurality of threaded segments within the cavity. The cap includes a plurality of projections engaging the plurality of threaded segments and the outer body to inhibit relative rotation between the plurality of threaded segments and the outer body. The plurality of projections is formed as a single piece with the cap. The threaded fastener further includes a snap ring removably coupled to the outer body to secure the cap within the cavity.

Abstract: The present invention is directed to a self locking tensioner that can be used to place a piston or stud in tension. The present invention is directed to a tensioner comprising slip wedges positioned between a piston and a body which houses the piston and the slip wedges.

Abstract: A nut having a nut body, a spring case, a washer, and a nut body urging spring. The nut body has received in it at least three or more nut segments and a nut segment urging spring, where the nut segments are, when rotated in the tightening direction after a bolt is inserted into the nut segments, screwed on to the thread of the bolt inserted. The spring case is attached at its upper end to the outer circumferential surface other than the upper part of the nut body so that the spring case is rotatable together with the nut body. The washer is rotatably attached to the lower part of the spring case. The urging spring is installed such that its one end received in the spring case is connected to the spring case or to the nut body and the other end to the washer, so that the urging spring can constantly urge the nut body in the tightening direction when the nut body is screwed on the bolt.

Abstract: The present invention is directed to a self locking tensioner that can be used to place a piston or stud in tension. The present invention is directed to a tensioner comprising slip wedges positioned between a piston and a body which houses the piston and the slip wedges.

Abstract: A facilitated tightening device allowing a bolt to be inserted smoothly by preventing a screw block engaged with the bolt from being inclined or falling down, comprising a base (2) having a bolt-insertion hole (7) partly forming a bolt-receiving face (9) and a slope portion (8) gradually decreasing in radius toward the insertion side of the bolt (6) in a manner so as to match the bolt-insertion hole (7) formed therein, a running screw (3) slid along the slope portion (8) as a result of the axial movement of the inserted bolt (6) to be engaged with the bolt (6), a spring piece (5) that presses the running screw (3) in the downward, in the diameter-reducing direction of the running screw (3), and guide projections (10, 11) that engage with the running screw (3) so as to prevent the screw block (3) from falling down into the base (2). Also, a groove for the running screw 2b is formed in the base 2 so as to prevent said running screw 3 from wobbling in the circumferential direction.

Abstract: A bolt coupling device which has a body with a chamber, an inlet and an outlet. The coupling device includes a coupling mechanism. The coupling mechanism includes a threaded surface along a bolt receiving channel. The coupling device includes a spring member that urges the threaded surfaces toward a first axis, and a cam member between two coupling segments which is rotatable. The cam member separates the first and second coupling segments to increase the dimension of the bolt receiving channel to selectively engage and disengage a bolt. The cam member can be positioned along a second axis which is parallel to the first axis or perpendicular to the first axis.

Abstract: An outer body of a nut defines an axial port and carries initial guide means. An inner body, movably accepted in the port in the axial direction, is divided into at least two jaws in the axial direction, which carry respectively an internal thread segment on their inner radial area. The jaws also include second guide means which interact with the first guide means in such a way that the jaws, when the outer body is moved relative to the inner body in a loosening direction, are moved radially outwards, and if the outer body is moved relative to the inner body in a tightening direction, are moved radially inwards. As the jaws can be moved when movement is in the radial direction, their internal thread segments can be brought smoothly into engagement with the outer thread of a threaded rod.

Abstract: A nut assembly for quick adjustment of axial position relative to a threaded shaft. The nut is formed in two, physically separate sections, each having a surface portion with threads for mating engagement with the shaft. Each nut section is pivotally mounted to a bushing which surrounds the threaded shaft for movement of the nut threads into and out of engagement with the shaft threads. The sections are moved about their pivotal mountings by movement of a second bushing axially with respect to the first bushing through cooperative conical surfaces on the second bushing and on each of the nut sections. In one embodiment the second bushing is physically separate from and is moved linearly with respect to the first bushing, and in a second embodiment the first and second bushings are threadedly connected to one another with relative rotation of the two producing the relative axial movement.

Abstract: A fastener includes a sleeve-like clamping element having a cavity extending in the direction of its longitudinal axis which accommodates a threaded stud. At least one clamping region is deformable into the cavity forming at least one clamping ramp inclined toward the longitudinal axis on an outside of the clamping element. A clamping sleeve pushed onto the clamping element in an installed state grips around the clamping element. A clamping sleeve inner surface cooperates with the clamping ramp so the clamping region reaches a clamping position deformed into the cavity to hold the threaded stud. The clamping element has a forward end flange in an installation direction. Coupling elements and mating coupling elements arranged on the flange and a clamping sleeve end facing the flange interlock in the installed state, preventing rotation between the clamping sleeve and clamping element.

Abstract: A quick coupling nut includes a body having a bore therethrough and adjacent side holes. A pair of threaded members are disposed in the bore and moveable in a radial direction of the bore and a cap having a bore therethrough, coaxial with the body bore, includes depending guides which are received by the guide holes for enabling axial movement between the cap and the body. Actuators depending from the cap engage the threaded members in order to urge the threaded members radially inward to engage a threaded bolt shank, extending through the cap and body bores, as the cap is moved axially toward the body. This threaded engagements enables tightening of the quick coupling cap by rotation about the threaded bolt shank.

Abstract: A mine roof bolt for use with a cable comprises a barrel having a first end and a second end, the second end having a rounded surface, a bore extending through the barrel between the first end and the second end and including a tapered portion, the bore sized to receive the cable, a pair of wedges sized for placement in the tapered portion of the bore and adapted to frictionally engage a cable disposed in the tapered portion of the bore, a recess defined in the first end of the barrel, and a driving nut sized for insertion in the recess and adapted for engagement by a driving tool.

Abstract: A quick mounting nut (2) movable, at least partially, without being rotated, axially to a threaded bolt (1), with a springing wire clip (4) being located in a nut housing (5) with a continuous coaxial opening (6), with the wire clip (4) at least partially engaging in a bolt thread (3) and having two legs (8, 8?) which spring relative to one another, with the opening (6) having an inner cone (7) which narrows radially from an axial neutral position of the wire clip (4) and with the wire clip (4) being movable axially to a limited extent and contacting at least partially inside the inner cone (7) in its locking position.

Abstract: A nut including a nut body having a polygonal outer wall and an inner wall defining the through hole being an inclined wall hole; a stopper formed as a stop flange; at least two guideposts formed coaxially on the inner wall of the nut body at the inclined wall hole; a spring disposed in the nut body between the stop flange and the at least three nut segments to bias the at least three nut segments toward the second end of the nut body; the nut body including an attachment part provided adjacent said second end, one of the attachment part with a fitting piece in order to attach rotatably and prevent to remove fixedly to a member with an axle hole and another attachment part attached to the attachment member by one of screwing and pressure.

Abstract: A plastic fastening element is configured to be fastened on a threaded bolt welded to a support member. The fastening element includes a first hollow element portion made of plastic material and having an axial through hole. The through hole has a polygonal cross section and radially resilient wall portions that will be radially outwardly deformed if the first element portion is pushed onto the threaded bolt. The fastening element also includes a second hollow annular element portion which is connected to one end of the first element portion by a breakable connecting portion. The second element portion has an inner cross section dimensioned such that the second element portion can be pushed over the first element portion under radial deformation of the resilient wall portions, whereby a thread of the threaded bolt is partially formed into the resilient wall portions of the first element portion.

Abstract: A quick insertion fastener has an internally threaded first member (“nut”) adapted to be quickly attached and tightened on an externally threaded second member (“bolt”). The nut is formed with a casing with an internal frusto-conical front surface, a plurality of threaded shell segments contained in the casing having external frusto-conical front surfaces which abut the front surface of the casing, a spring member positioned at a rear part of the casing which elastically holds the rear ends of the shell assembly together, and an end retainer provided at the rear part of the casing having a taper for engaging the rear ends of the shell assembly and displacing them radially apart when the shell assembly is displaced axially toward the end retainer by insertion of the bolt. This allows the bolt threads to move without interference past the internal threads of the shell segments.

Abstract: The present invention provides a threaded fastening device assembly including an outer member having an upwardly extending and circumferentially disposed body with a non-threaded inner and outer surface, at least two inner members, each inner member having an internal surface which is threaded and an outer surface that is complimentary in shape to said inner surface of said outer member, wherein, said outer member is adapted to be slideably engageable with said inner members and wherein in use, said fastening assembly is rotatable and engageable with a complimentary threaded fastening shaft.

Abstract: An internally threaded, segmented nut and conical bore for a pressure vessel are used to make removal of studs securing covers over openings through the pressure vessel wall. The segmented nut has a conical upper surface to mate with a corresponding surface of the conical bore when the stud is threaded through the internal thread of the nut and a load is applied. The segmented nut is easily replaced and the stud is easily removable due to the shape of the nut and bore. The segmented nut eliminates drilling and rethreading the bore to repair damaged threads.

Abstract: A quick mounting nut (2) movable, at least partially, without being rotated, axially to a threaded bolt (1), with a springing wire clip (4) being located in a nut housing (5) with a continuous coaxial opening (6), with the wire clip (4) at least partially engaging in a bolt thread (3) and having two legs (8, 8′) which spring relative to one another, with the opening (6) having an inner cone (7) which narrows radially from an axial neutral position of the wire clip (4) and with the wire clip (4) being movable axially to a limited extent and contacting at least partially inside the inner cone (7) in its locking position.

Abstract: A nut assembly (10) for engaging an externally threaded bolt (12). Nut assembly (10) includes a cylindrical casing (16) and a nut (20) secured to cylindrical casing (16) projects a substantial distance from cylindrical casing (16) to permit rotation of nut assembly (10) by a suitable conventional wrench. Three internally threaded arcuate segments (28) are mounted within cylindrical casing (16) to engage external screw threads (14) on bolt (12). Detents (40) are formed integrally with cylindrical body (16) and project radially inwardly of the inner peripheral surface (24) of cylindrical casing (16). Detents (40) fit in grooves (41) in segments (28) to connect segments (28) for rotation with cylindrical body (16) and cap (20).

Abstract: A nut comprises a nut body having a polygonal outer wall and an inner wall defining the through hole being an inclined wall hole; a stopper formed as a stop flange; at least two guideposts formed coaxially on the inner wall of the nut body at the inclined wall hole; a spring disposed in the nut body between the stop flange and the at least three nut segments to bias the at least three nut segments toward the second end of the nut body; the nut body including an attachment part provided adjacent said second end, one of the attachment part with a fitting piece in order to attach rotatably and prevent to remove fixedly to a member with an axle hole and another attachment part attached to the attachment member by one of screwing and pressure, so that while structure is easy and can attach easily, attachment member can be used as a washer and it can manufacture at low cost.

Abstract: A threaded fastener for use with bolt comprises a housing having a central bore that includes a bolt insertion aperture and a plurality of cylindrical and frustoconical steps. A plurality of insert segments are placed within the central bore. Each insert segment includes an inwardly facing threaded portion and a front projection extending outwardly from the threaded portion. The front projection has a beveled edge arranged for sliding contact with a corresponding beveled portion of the housing. The front projection also has outwardly extending portion that cooperates with a ledge in the housing bore to limit longitudinal movement of the insert segment in the housing. A rear projection extends inwardly from the threaded portion and is arranged for sliding contact with a second beveled surface of the housing. An end cap retains the insert segments in the housing.

Abstract: A tendon 10 is installed in a hole 34 in a mine hanging wall 36 by making use of a barrel 14 and a wedge arrangement 16. One end of the tendon is anchored in the hole 34 such that the other end protrudes therefrom. The barrel 14 is positioned over the protruding end of the tendon 10. A tensioning jack applies a tensile load to the tendon 10 and an oppositely disposed load to a shear ring 20 of the barrel. When the desired preload is reached the shear ring 20 fails permitting the tensioning jack 40 to displace wedge elements 30 of the wedge arrangement 16 inwardly thereby locking the barrel on the tendon and maintaining the desired preload in the tendon.

Abstract: A spare-tire fastening structure is for fastening a spare-tire 1 to a support member (bracket 2) in a spare-tire receiving section. The fastening structure comprises a nut member 5 and a bolt member 9.

Abstract: A pipe joint provided with a joint main body having a tapered female screw portion on an opening end, and a cylindrical retainer having a male screw portion screwed into the female screw portion and plural small-disc continuous bodies each of which is composed of two or three small discs for pipe fixation embedded in the male screw portion along with the thread as a part of the small disc protrudes from a peripheral side and another part of the small disc protrudes from an inner peripheral face.

Abstract: A spreading anchor including a sleeve (2) having an expansion region (3) provided with longitudinal slots (4), and an axial bore (5) having a conical shape in the expansion region (3) conically tapering toward a rear, with respect to a setting direction (5) end (6) of the sleeve (2), and a spreading member (8) having a conical profile at least along a portion of its longitudinal extent and displaceable in the axial bore (5) upon radial expansion of the sleeve expansion region (3), the spreading member (8) having a cylindrical through-bore (9) and being formed of tensioning segments (11-14) which extend in an axial direction and are held together with a possibility of a radial resilient expansion.

Abstract: An improved axial-on threaded coupling device is provided for push-on mounting to a substantially seated position on a male threaded member. The device includes a plurality of threaded coupling segments collectively forming a female threaded bore within a housing and configured for radial expansion to accommodate push-on mounting onto a male threaded member. When the device is rotated in a tightening direction, the segments are retained in threaded engagement with the male threaded member by the inner wall surfaces of the housing. When the device is rotated in an opposite direction, the fastener segments are free to expand radially outward to accommodate pull-off removal of the device from the male threaded member.

Abstract: A nut main body has a slanted hole with a smaller inner end portion having a plurality of stepped portions of differing height. This gives the slanted hole a differing depth relative to a large-diameter end portion of the slanted hole at a plurality of locations about a circumference of the slanted hole. A plurality of nut segments are slidable within the slanted hole and come into contact with at least one of the stepped portions. The nut segments have screw threads at an inner wall surface. A washer is provided at a large-diameter side of the plurality of nut segments. A bias spring is attached within the nut main body so as to urge the plurality of nut segments towards the small-diameter side of the nut main body with the washer therebetween. A stopper piece holds the bias spring within the nut main body.