Rotatable socket

Abstract

The present invention relates to a rotatable socket. The present rotatable socket accommodates for the orientation of the fastener, in particular a jackbolt, whilst receiving a spindle. The present rotatable socket assists in the process for simultaneously torquing fasteners, such as jackbolts or a multi jackbolt tensioner.

Description

TITLERotatable SocketFIELD OF THE INVENTION

[0001] The present invention relates to the field of fastening, tensioning and / or torquing fasteners. Particularly, the present invention relates to a rotatable socket. More particularly, the present invention relates to a rotatable socket for use with an apparatus for simultaneously applying torque or tension to a plurality of jackbolts.BACKGROUND TO THE INVENTION

[0002] Any reference to background art herein is not to be construed as an admission that such art constitutes common general knowledge in Australia or elsewhere.

[0003] A Multi-Jackbolt Tensioner (MJT), such as the tensioner sold under the Superbolt® brand, is generally used as a direct replacement for hex nuts, covered nuts, bolts, etc. of a size typically of 1" or greater. A conventional (nut based) MJT threads onto an existing bolt or stud providing a highly effective means to “bolt up the joint”. The typical MJT consist of three components, i) a hardened washer to provide a hardened, flat surface for the jackbolts to “push” against; ii) an often round nut body that threads onto the existing bolt or stud and seats hand tight against the washer initially; and iii) a polar array of jackbolts that thread through the nut body so that their points force against the washer to pretension the bolt or stud.

[0004] MJTs have addressed some significant problems from the past. However, the use of MJTs also have a some problems which need to be addressed. Specifically, each jackbolt of the MJT must be separately tightened. Some industrial applications require implementation of multiple MJTs and in such applications, the tightening of each jackbolt can become time consuming.Typically, the tightening of jackbolts involves the use of a wrench or a hand held tool with a socket whereby each jackbolt needs to be individually tightened.

[0005] A prior art device that is able to tighten multiple jackbolts simultaneously is described in PCT / US2018 / 057923 entitled ‘apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner’, the content of which is hereby incorporated by reference. In this reference, the system comprises a tensioning apparatus that is separate from the power transfer assembly. The tensioning apparatus is orientated to receive each of the jackbolts of the plurality of jackbolts of the MJT, and then the power transfer assembly is subsequently connected to the tensioning assembly to drive rotation of the jackbolts. It will be appreciated that in the event of a day that many MJTs may require tightening and that this two-step process may be time consuming.

[0006] It would be advantageous to address one or more of the above issues and / or provide the consumer with a commercial alternative. Particularly, it would be advantageous to provide a device that could locate on the jackbolts without requiring the location of the jackbolts prior to assembly.SUMMARY OF THE INVENTION

[0007] In a first aspect, although it need not be the only or indeed the broadest aspect, the invention resides in a rotatable socket comprising: a drive socket portion having a first opening adapted to receive a spindle; and a socket head portion having a second opening adapted to receive the head of a fastener, wherein the rotatable socket is adapted to provide a backlash to accommodate rotation of the fastener.

[0008] In an embodiment, the first opening comprises a dodecagon cross- sectional shape.

[0009] In certain embodiments, the dodecagon cross-sectional shape is adapted to receive the spindle at the backlash angle.

[0010] In one embodiment, the first opening comprises a flaring.

[0011] In embodiments, the rotatable socket further comprises an aperture adapted to receive a dowl pin of the spindle.

[0012] In some embodiments, the socket head portion comprises a predetermined cross-sectional shape. In one embodiment, the predetermined cross-sectional shape comprises a hexagonal cross-sectional shape or a dodecagram polygon cross-sectional shape.

[0013] In a particular embedment, the rotatable socket further comprising a formation between the first opening and second opening adapted to prevent either the fastener or the spindle from progressing beyond.

[0014] In an embodiment, the backlash is between about 1° and about 30°, between about 5° and about 30°, between about 10° and about 30°, between about 10° and about 25°, between about 15° and about 25°, or about 20°. In a preferred embodiment, the backlash is about 20°.

[0015] In one embodiment, an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprises the spindle.

[0016] In a preferred embodiment, the spindle terminates in a square crosssection.

[0017] In certain embodiments, the rotatable socket for use with an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprises the spindle. In another embodiment, the rotatable socket when used with an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprises the spindle.

[0018] In embodiments, the invention resides in an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprising at least one rotatable socket according to the first aspect.

[0019] In a second aspect, the invention resides in a method of simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner including: providing the rotatable socket comprising a drive socket portion having a first opening adapted to receive a spindle, and a socket head portion having a second opening adapted to receive the head of a jackbolt, wherein the rotatable socket is adapted to provide a backlash to accommodate rotation of the fastener; locating a spindle in the first opening; locating the heads of each of the plurality of the jackbolts in the second opening; and applying torque to the spindle; to thereby simultaneously apply torque to a plurality of jackbolts.

[0020] The rotatable socket and components thereof may be as substantially described hereinabove.

[0021] In a third aspect, the invention resides in a tool for simultaneously tightening a plurality of jackbolts of a MJT, the tool including a plurality of drive spindles powered by common drive shaft, each of the plurality of drive spindles coupled to a rotatable socket of the first aspect, wherein each rotatable socket is rotationally aligned with a jackbolt of an MJT to be tightened prior to operating the common drive shaft.

[0022] The rotatable socket and components thereof may be as substantially described hereinabove.

[0023] The various features and embodiments of the present invention referred to in the individual sections above and in the description which follows apply, as appropriate, to other sections, mutatis mutandis. Consequently, features specified in one section may be combined with features specified in other sections as appropriate.

[0024] Further features and advantages of the present invention will become apparent from the following detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, embodiments of the invention will be described by way of example only with reference to the accompanying drawings, in which:FIG 1 shows an embodiment of a rotatable socket;FIG 2 shows a different view of the embodiment shown in FIG 1 ;FIG 3 shows a side view of an embodiment of the rotatable socket showing the internal features thereof in dotted lines;FIG 4 shows an alternate side view of the rotatable socket of FIG 3 showing the internal features thereof in dotted lines;FIG 5 shows a view of the socket head portion of the rotatable socket and an enlarged view of the flaring thereof;FIG 6 shows a view of the drive socket portion of the rotatable socket and an enlarged view of the flaring thereof;FIG 6a shows a square cross section of a terminal end of a spindle;FIG 6b shows a second square cross section overlaid on the square shown in FIG 6a rotated at 20°.FIG 6c shows the dodecagon polygon cross section of the dodecagon shape of the first aperture;FIG 7 shows an exploded view of a tensioning apparatus for MJTs;FIG 8 shows a top view of the tensioning apparatus;FIG 9 shows a bottom view of the tensioning apparatus;FIG 10 shows a view of the bottom of the tensioning apparatus with black plate removed;FIG 11 shows a view of the tensioning apparatus cross sectioned through a first plane;FIG 12 shows a view of the tensioning apparatus cross sectioned through a second plane;FIG 13 shows tensioning apparatus with cover removed, mounted to a power transfer unit;FIG 14 shows a cross sectional view of the tensioning apparatus mounted to the power transfer unit; andFIG 15 shows a tool for simultaneously tightening a plurality of jackbolts of a M JT.DETAILED DESCRIPTION OF THE INVENTION

[0026] Embodiments of the present invention reside primarily in a rotatable socket. Accordingly, the device, system or method steps have been illustrated in the drawings, showing only those specific details that are necessary for understanding the embodiments of the present invention, but so as not to obscure the disclosure with excessive detail that will be readily apparent to those of ordinary skill in the art having the benefit of the present description.

[0027] In this specification, adjectives such as first and second, inner and outer, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order.

[0028] Words such as “comprises” or “includes” are intended to define a nonexclusive inclusion, such that a device, system or method that comprises a list of elements does not include only those elements but may include other elements not expressly listed, including elements that are inherent to such a device, system or method.

[0029] As used herein, the term ‘about’ means the amount is nominally the number following the term ‘about’, but the actual amount may vary from this precise number to an unimportant degree.

[0030] The present invention is predicated on, at least, the finding that the present rotatable socket can be utilized with an apparatus for simultaneouslyapplying torque to a plurality of jackbolts of a multi jackbolt tensioner which accommodates for adjustment for the orientation of each jackbolt. The present rotatable socket can be installed, or utilized, with the tensioning apparatus prior to location of jackbolts thereon by virtue of the rotatability thereof. This allows for a unitary device to be provided where the rotatable sockets can be individually located on respective jackbolts without the need to disengage them to the spindle or disengagement / engagement of the power transfer assembly from the tensioning device.

[0031] Shown in FIGs 1 and 2 are perspective views of an embodiment of a rotatable socket. The rotatable socket 100 comprises a body 110. In one embodiment, the body comprises an elongate member. In the embodiment shown, the body comprises a rod. The body 110 comprises a drive socket portion 120 and a socket head portion 130. In one embodiment, the drive socket portion 120 is formed in a first end of the body 110. In embodiments, the socket head portion 130 is formed in a second end of the body 110. Preferably, the first end opposes the second end. That is, in one embodiment, the socket head portion opposes the drive socket portion.

[0032] The drive socket portion 120 comprises a first opening 121 adapted to receive a spindle. In a preferred embodiment, the spindle is from or part of an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner. The spindle suitably terminates in a square cross section for engaging the drive socket portion of the rotatable socket. In the present embodiment, the spindle comprises or terminates in a square cross section. In one embodiment, an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprises a plurality of spindles.

[0033] The rotatable socket is adapted to provide a backlash to accommodate rotation of the fastener (and thus head thereof). Backlash, sometimes called lash, play, or slop, is a clearance or lost motion in a mechanism caused by gaps between the parts. In a preferred embodiment, the rotatable socket 100 is adapted to provide a blacklash of between about 1° and about 30°, or between about 5° and about 30°, between about 10° and about 30°, between about 10° and about 25°, between about 15° and about 25°, orabout 20° with respect to the spindle. That is, the spindle can be received in the spindle head portion at the above backlash angles.

[0034] In an embodiment, the first opening 121 comprises a dodecagon shape 122. The dodecagon shape allows for the square cross section of the spindle to be received therein. The dodecagon shape allows for the square cross section of the spindle to be received therein at certain angles. In this regard, clearance is provided relative to the spindle such that the spindle can be received in the first opening at an angle (and not completely aligned). In use, when the spindle is received in the first opening, the rotation of the spindle causes engagement or abutment with the walls of the dodecagon and this rotates the body (and thus the socket head portion and jackbolt head received therein). In certain embodiments, the socket head portion is adapted to receive the spindle at an angle of between about 1° and about 30°C, or between about 5° and about 30°, between about 10° and about 30°, between about 10° and about 25°, between about 15° and about 25°, or about 20°. For instance, the square spindle can be received at an angle of between the above ranges and the tightening or loosening thereof can be applied by the spindle.

[0035] In other words, the first opening 121 comprises a first aperture having a dodecagon cross section. In an embodiment, the dodecagon cross section is flared, or extending outwardly or radially, near the surface of the first end. In one embodiment, the walls of the flaring 123 form an obtuse angle with the walls of the dodecagon aperture. In one embodiment, the obtuse angle is between about 91° and about 179°, between about 91° and about 150°, between about 91° and about 120°, between about 100° and about 120°, between about 110° and about 120°, or between about 115° and about 120° or about 118°. In one embodiment, the flaring is present to the periphery of the socket, or adjacent the periphery of the socket. The flaring preferably does not reach the periphery of the socket to provide structural strength to the opening.

[0036] In a preferred embodiment, the first aperture is flared towards the opening to facilitate location of the spindle. It will be appreciated that flaring 123 allows for the spindle or square cross section thereof to be more easily receivedtherein prior to engaging the dodecagon aperture 122. The flaring suitably also assists in centralization of the spindle in the first aperture.

[0037] In one embodiment, the first aperture comprises an inner section and an outer section. The inner section comprises a constant dodecagon cross section. The outer section comprises the flaring. The flaring also comprises a dodecagon cross section; however, the flaring has an increasing dodecagon cross section towards the surface or end thereof.

[0038] The dodecagon 122 suitably comprises 12 sides. The dodecagon is preferably defined by a pair of squares where one square is offset or rotated by between about 1° and about 30°, between about 1° and about 25°, between about 5° and about 30°, between about 10° and about 30°, between about 5° and about 25°, between about 10° and about 25°, between about 15° and about 25°, or about 20° when overlaid.

[0039] Shown in FIG 6a is a square that is substantially the same dimensions or size as a terminal square cross section of the spindle. Fig 6b shows a second square that is overlaid on the square of FIG 6a but rotated by about 20°. Shown in FIG 6c is an embodiment of the dodecagon 122 where the corners of the squares are connected to the closest corners and this results in the dodecagon.

[0040] The rotatable socket 100 further comprises an aperture 140 adapted to receive a dowl pin of the spindle. The aperture 140 ensures that the spindle remains engaged with the rotatable socket and alleviates the problem of the rotatable socket 100 disengaging from the spindle. The person skilled in the art will appreciate that the aperture 140 is also adapted to accommodate for the above backlash when a dowl pin is received therein. In this regard, the aperture 140 is suitably sized and dimensioned to accommodate and provide the above backlash. In one embodiment, the aperture 140 is suitably an elongate aperture.

[0041] As mentioned above, the socket head portion 130 comprises a second opening 131. The second opening 131 is adapted to receive a head of a jackbolt. The second opening 131 is sized and dimensioned to receive the head of a jackbolt or fastener therein. In one embodiment, the second opening 131 comprises a bore 132 having a predetermined cross section. In an embodiment,the bore comprises or is dodecagram polygon cross section or a hexagon cross section. In a preferred embodiment, the bore having a dodecagram polygon is flared towards the opening to facilitate location of the jackbolt head therein. It will be appreciated that the flaring 133 allows for the head of the jackbolt or fastener to be more easily received therein prior to engagement with the dodecagram polygon. The person skilled in the art will appreciate that the second aperture can be any shape that is adapted to engage the jackbolt or fastener head. In one embodiment, the second aperture comprises a hexagon shape.

[0042] In other words, the second opening 131 comprises a second aperture having a dodecagram polygon cross section. In one embodiment, the second opening 131 comprises 12 points. In one embodiment, the dodecagram polygon is flared, or extending outwardly or radially, near the surface of the socket head portion 130. In one embodiment, the walls of the flaring 133 form an obtuse angle with the walls of the dodecgram polygon shape. In one embodiment, the obtuse angle is between about 91° and about 179°, between about 91° and about 150°, between about 91° and about 120°, between about 100° and about 120°, between about 110° and about 120°, or between about 115° and about 120° or about 118°. In one embodiment, the flaring is present to the periphery of the socket, or adjacent the periphery of the socket. The flaring preferably does not reach the periphery of the socket to provide structure strength to the opening.

[0043] In one embodiment, the walls of the flaring 133 are angled relative to the adjacent wall. For example, the walls 133a and adjacent wall 133b are angled relative to each other. In one embodiment, the angle is between about 100° and about 130°, between about 110° and about 120°, between about 115° and about 120°, or about 118°.

[0044] In one embodiment, the second aperture comprises an inner section and an outer section. The inner section comprises a constant dodecagram polygon cross section. The outer section comprises the flaring. The flaring also comprises a dodecagram polygon cross section; however, the flaring has an increasing dodecagram polygon cross section towards the surface or endthereof. The flaring suitably assists in centralization of the head of the jackbolt or fastener in the second aperture.

[0045] Typically, the head of a jackbolt or fastener comprises a hex shape or cross section. The provision of a dodecagram polygon allows for the hex head to be fit therein more readily. This shape along with the dodecagon cross section of the drive socket portion allows for a certain amount of rotation to accommodate the hex head at different angles. This facilitates location of the jackbolt head in the second opening.

[0046] In one embodiment, the first opening 121 and the second opening 131 form a channel through the body 110. In this embodiment, the body 110 comprises a formation 150 at the junction between the first opening 121 and the second opening 131 preventing either the spindle or the jackbolt head from proceeding in the other opening or coming into contact with each other. It is postulated that this avoids any friction and possible failure thereof. The formation 150 provides a point whereby the jackbolt head or spindle cannot extend beyond. In one embodiment, the first opening 121 and second opening 131 may be in form of a blind hold. It will be appreciated that this structure also prevents the jackbolt or the drive spindle from entering the other opening.

[0047] The present rotatable sockets allow for a unitary device to be utilized in applying torque to a plurality of jackbolts of a multi jackbolt tensioner. In this regard, the rotatable socket can be located on the spindles of the unitary device. Once located, each jackbolt of the plurality of jackbolts of the multi jackbolt tensioner are suitably located in a respective socket head portion of a respective rotatable socket. The backlash allows for the rotatable socket to be rotated to accommodate for the orientation of the head of the jackbolt whilst still being connected to the spindle. Once the head of each of the jackbolts has been located in a respective rotatable socket head then torque can be simply applied to torque the plurality of jackbolts simultaneously.

[0048] In one embodiment, the tensioning apparatus is described in FIGs 7 to 14. FIGs 7 to 14 comprise various views of a tensioning apparatus 200 for simultaneously tensioning jackbolts of an MJT according to an embodiment of the present invention.

[0049] The tensioning apparatus 200 includes a housing 202 that is comprised of a first portion being a back plate 204, and a second portion being a cover 206, which fasten together to define an internal space. The back plate 204 is formed as an annulus with a central circular hole 208. In the presently described embodiment the housing presents as squat cylinder with a longitudinal axis 221. It will be realised that in other embodiments the housing 202 may be of a different shape.

[0050] A planetary gear assembly (PGA) 210 is located coaxially within the housing 202. The planetary gear assembly comprises a bottom plate 212 and a top plate 214. Three planetary gears 216 are journaled between the bottom plate 212 and the top plate 214. The planetary gears are equiangularly disposed around the central axis 221 of the housing at 120 degrees. Supports 218 are fastened between the base plate and the top plate and are disposed alternately between the planetary gears 216. The supports are formed with arcuate concave sides shaped to complement peripheral portions of the planetary gears 216.

[0051] The cover 206 of the housing 202 is internally formed with a central, circular recess 220 (identified in Figures 11, 12) opposite the back plate centre hole 208 for registering with the top plate 214 of the planetary gear assembly 210. The top plate 214 is then fastened to the cover by means of suitable bolts 229 (identified in Figure 8 only) so that the top plate 214 and thus the planetary gear assembly (PGA) 210 is fast with the housing 202.

[0052] A ring gear 222 encircles the planetary gears 216. The ring gear 222 is toothed on its inside wall and also on its outside wall. The inside wall of the ring gear 222 meshes with each of the planetary gears 216.

[0053] A plurality of spindle gears 224 are retained in the housing 202 equiangularly and located at a common radial distance from axis 221. The spindle gears 224 are disposed about the ring gear 222 and mesh with its outside wall. Each spindle gear 224 is comprised of a gear disk 224a, i.e. a disk with toothed periphery, and a spindle 224b that extends coaxially from the gear disk.

[0054] In the preferred embodiment of the invention that is illustrated herein, the spindles 224b of the spindle gears 224 are journaled between the back plate 204 and the cover 206 of the housing 202 by means of corresponding holes and bearings 223a, 225a and 223b, 225b of the base plate 208 and the cover 206. The cover end of each of the spindles 224b extends beyond the cover 206 of the housing 202 and terminates in a square cross section 227 for receiving a rotatable socket 100 (shown with a hex shaped socket head portion). It will be observed that the gear disks 224a of adjacent spindle gears 224 are axially offset so that adjacent gear disks are overlapped. Overlapping of the adjacent spindle gears 224 allows for the angular separation between them to coincide with the positions of jackbolts on an intended MJT for tensioning. For example, it may be seen in Figure 10 that the gear disks 224a1, 224a2 and 224a3 of three adjacent spindle gears are axially offset through three levels. This is possible due to the height of the ring gear 222 being about three times greater than the height of each of the gear disks 224a so that each gear disk is able to mesh with the ring gear at one of the three different levels. Depending on the number of spindle gears 224 that must be located around the axis of the tensioning unit, the number of levels that are required may be increased or decreased.

[0055] In the presently described embodiment the ratio of gear diameters from each planetary gear to the ring gear to each spindle gear results in an overall speed reduction, from the planetary gears to the spindle gears, of 2:1 and a torque multiplication of about 1:2 so that the delivered torque is approximately doubled.

[0056] In an optional embodiment, the tensioning apparatus may be separate to the power transfer assembly. Figure 13 shows the tensioning apparatus 200, with cover 206 removed, mounted to a power transfer assembly 300. The power transfer assembly 300 comprises a transmission between a drive, such as an electric, pneumatic or hydraulic motor, and the tensioning apparatus 200. Figure 14 is a cross sectional view in the direction indicated through cross section B-B’ of Figure 13, of the tensioning apparatus 200 mounted to the power transfer assembly 300. As can be seen in Figure 14, the power transfer assembly 300 includes a worm 370 that meshes with a worm wheel 310. A preferred worm andworm wheel arrangement which is specifically designed for high torque transfer is discussed in international patent publication No. WO 2016 / 141407 in the name of Nord-Lock Australia Pty Ltd, the content of which is hereby incorporated by reference. In use the worm 370 is coupled to a shaft of the motor by means of connector 303 (Figure 13). The drive assembly, for example the motor, is typically provided with an output shaft including a standard, typically square, end that is designed to be inserted into a socket such as connector 303 of the power transfer assembly 300.

[0057] The central worm wheel 310 is journaled in the power transfer assembly housing 320 along a central drive gear axis 311. The central drive gear axis defines a longitudinal axis for the power transfer assembly 300. The power transfer assembly housing has first and second opposed sides of disposed on opposite sides of the gear wheel through which the first and second ends of the drive gear extend. It will be observed in Figure 13 that the first and second opposed sides are formed with a peripheral lip that defines a recess for registering with the first part of the housing of the tensioning apparatus.

[0058] The worm wheel 310 comprises an outwardly extending shaft 312, with ends that terminate in drive gears 313a and 313b. Each drive gear 313a, 313b is adapted to be coupled with the tensioning apparatus 200. The drive gear, either 313a or 313b passes through a coaxial central hole 215 (Figure 13) in PGA-bottom plate 212 in order to mesh with the planetary gears 216.

[0059] Accordingly, assuming that the worm 370 is always driven in a single direction, coupling the tensioning apparatus 200 to drive gear 313a drives the spindles 224b, and thus coupling sockets 226, in a first direction for tightening jackbolts, whereas coupling the tensioning apparatus 200 to drive gear 313b drives the spindles in a second direction for loosening jackbolts. The spindles 224b of the tensioning apparatus 200 are then aligned with the jackbolts of the MJT and coupled thereto by means of coupling sockets 226. A power source, such as an electric or pneumatic motor is then coupled to the input socket 303 of the power transfer assembly 300. Operation of the power source causes the worm 370 and thus the wormwheel 310 of the power transfer assembly 300 to rotate thereby rotating the drive gear 313a. Consequently, each of the planetarygears 216 rotates thereby causing the ring gear 222 to rotate. The rotation of the ring gear 222 in turn causes each of the spindle gears 224 to rotate. As the spindle gears 224 rotate so to do their spindles 224b and thus the attached coupling sockets 226 thereby imparting torque to each of the jackbolts of the MJT and thus causing them to rotate and tension. In one embodiment, the power transfer assembly 300 is formed with the tensioning apparatus.

[0060] When it is desired to loosen jackbolts of an MJT an analogous process is carried out except that the tensioning apparatus 200 is coupled to the reverse side of the power transfer assembly 300. In this configuration drive gear 313b (as opposed to 313a) meshes with each of the planetary gears 216, thereby causing rotation in an opposite direction of the spindle gears and loosening of the jackbolts.

[0061] If necessary, for example for servicing, the planetary gear assembly 210 may be removed through the base plate 208 once the top plate 214 has been unbolted from the cover 206. The planetary gear assembly can then be quickly replaced with a functioning unit without having to disassembly the entire unit. The ring gear 222 is retained in its position by virtue of it meshing with the spindle gears 224 and the planetary gears 216. Parts internal to the housing 202 are packed with grease for lubrication.

[0062] While the specific embodiment of the invention that has been described herein has eleven spindle gears and thus is specifically designed for tightening a MJT having eleven jackbolts, it will be realised that variations of the invention with fewer or more spindle gears are possible to suit MJTs with a fewer or greater number of jackbolts.

[0063] The person skilled in the art will appreciate that the power transfer unit may be formed with the tensioning apparatus. In this regard, the jackbolts of the MJT can be located or received in the socket head portion whilst engaged to the tensioning apparatus. The socket head portion and drive socket portion of the rotatable socket allow for adjustment and orientation of the socket head portion relative to the orientation of the head of the jackbolt whilst secured to the spindle, and this allows for the head to be located in the socket head portion. Advantageously, this does not require the power transfer unit to be disconnectedfrom the tensioning apparatus and allows for a much more efficient process of tightening the jackbolts in a MJT. In this regard, in one embodiment, the power transfer unit may be unitary formed with the tensioning apparatus.

[0064] The person skilled in the art will appreciate that any rotary tool, any electric motor, pneumatic motor, or other mechanism(s) could be utilized as the power transfer unit to apply torque to the spindles and thus the rotatable sockets. Furthermore, the person skilled in the art will appreciate that the power transfer unit can be formed with the tensioning assembling by utilizing the present rotatable sockets.

[0065] In an aspect, the invention resides in a tool for simultaneously tightening a plurality of jackbolts of a MJT, the tool including a plurality of drive spindles powered by common drive shaft, each of the plurality of drive spindles coupled to a rotatable socket of the first aspect, wherein each rotatable socket is rotationally aligned with a jackbolt of an MJT to be tightened prior to operating the common drive shaft.

[0066] Shown in FIG 15 is an embodiment of a tool for simultaneously tightening a plurality of jackbolts for a MJT. The tool 1500 comprises a plurality of spindles power by a common drive shaft. Each of these plurality of drive spindles is coupled to a rotatable socket 100. Each rotatable socket 100 can suitably be rotationally aligned with a respective jackbolt of a MJT to be tightened prior to operating the common drive shaft. It will be appreciated that the rotatability, as discussed above, allows for the jackbolts of a MJT to be aligned with the rotatable socket whilst coupled to the spindle. This facilitates location of the jackbolts of the MJT into the socket.

[0067] The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment.

[0068] As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have beendiscussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this invention is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims

CLAIMS1. A rotatable socket comprising: a drive socket portion having a first opening adapted to receive a spindle; and a socket head portion having a second opening adapted to receive the head of a fastener, wherein the rotatable socket is adapted to provide a backlash to accommodate rotation of the fastener.

2. The rotatable socket of claim 1, wherein the first opening comprises a dodecagon cross-sectional shape.

3. The rotatable socket of claim 2, wherein the dodecagon cross- sectional shape adapted to receive the spindle at the backlash angle.

4. The rotatable socket of any one of the preceding claims, wherein the first opening comprises a flaring.

5. The rotatable socket of any one of the preceding claims, further comprising an aperture adapted to receive a dowl pin of the spindle.

6. The rotatable socket of any one of the preceding claims, wherein the socket head portion comprises a predetermined cross-sectional shape.

7. The rotatable socket of claim 6, wherein the predetermined cross- sectional shape comprises a hexagonal cross-sectional shape or a dodecagram polygon cross-sectional shape.

8. The rotatable socket of any one of the preceding claims, further comprising a formation between the first opening and second opening adapted to prevent either the fastener or the spindle from progressing beyond.

9. The rotatable socket of any one of the preceding claims, wherein the backlash is between about 1° and about 30°, between about 5° and about30°, between about 10° and about 30°, between about 10° and about 25°, between about 15° and about 25°, or about 20°.

10. The rotatable socket of any one of the preceding claims, wherein an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprises the spindle.

11. The rotatable socket of any one of the preceding claims, wherein the spindle terminates in a square cross-section.

12. The rotatable socket of any one of the preceding claims for use with an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprises the spindle.

13. The rotatable socket of any one of claims 1 to 11 when used with an apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprises the spindle.

14. An apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner comprising at least one rotatable socket according to any one of claims 1 to 11.

15. A method of simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner including: providing the rotatable spindle a drive socket portion having a first opening adapted to receive a spindle, and a socket head portion having a second opening adapted to receive the head of a jackbolt, wherein the rotatable socket is adapted to provide a backlash to accommodate rotation of the fastener; locating a spindle in the first opening; locating the heads of each of the plurality of the jackbolts in the second opening; and applying torque to the spindle; to thereby simultaneously apply torque to a plurality of jackbolts.

16. A tool for simultaneously tightening a plurality of jackbolts of a MJT, the tool including a plurality of drive spindles powered by common drive shaft, each of the plurality of drive spindles coupled to a rotatable socket of any one of claims 1 to 11 , wherein each rotatable socket is rotationally aligned with a jackbolt of an MJT to be tightened prior to operating the common drive shaft.

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