WO1995033598A1 - A method of tensioning and de-tensioning a bolt - Google Patents

A method of tensioning and de-tensioning a bolt Download PDF

Info

Publication number
WO1995033598A1
WO1995033598A1 PCT/GB1995/001265 GB9501265W WO9533598A1 WO 1995033598 A1 WO1995033598 A1 WO 1995033598A1 GB 9501265 W GB9501265 W GB 9501265W WO 9533598 A1 WO9533598 A1 WO 9533598A1
Authority
WO
WIPO (PCT)
Prior art keywords
bolt
nut
flange
carrier
tensioning
Prior art date
Application number
PCT/GB1995/001265
Other languages
French (fr)
Inventor
David Campbell
Original Assignee
Hedley Purvis Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hedley Purvis Limited filed Critical Hedley Purvis Limited
Priority to AU26232/95A priority Critical patent/AU2623295A/en
Publication of WO1995033598A1 publication Critical patent/WO1995033598A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P19/00—Machines for simply fitting together or separating metal parts or objects, or metal and non-metal parts, whether or not involving some deformation; Tools or devices therefor so far as not provided for in other classes
    • B23P19/04—Machines for simply fitting together or separating metal parts or objects, or metal and non-metal parts, whether or not involving some deformation; Tools or devices therefor so far as not provided for in other classes for assembling or disassembling parts
    • B23P19/06—Screw or nut setting or loosening machines
    • B23P19/067—Bolt tensioners
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B29/00—Accessories
    • B25B29/02—Bolt tensioners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B31/00—Screwed connections specially modified in view of tensile load; Break-bolts
    • F16B31/04—Screwed connections specially modified in view of tensile load; Break-bolts for maintaining a tensile load
    • F16B31/043—Prestressed connections tensioned by means of liquid, grease, rubber, explosive charge, or the like

Definitions

  • This invention relates to a method of tensioning and de-tensioning a bolt hydraulically and has particular though not exclusive application in sub-sea or other situations where access to the joint to be bolted is restricted.
  • Such a procedure is normally under manual control, and, in sub-sea situations in which the procedure is extensively used, the manual functions are carried out by divers.
  • a method of tensioning a bolt interconnecting first and second flanges, the bolt carrying a primary nut to be tightened characterised by the steps of: locating the bolt to be tensioned in a carrier incorporating hydraulic tensioning means; positioning the carrier on the first flange with the lower end extent of the bolt carried thereby extending through the flanges; providing anchor means at or adjacent the second flange into which said lower end extent of the bolt is received to be retained thereby; actuating the hydraulic tensioning means to tension the bolt by reaction against the first flange; turning the primary nut relative to the bolt into an operative position to retain said tension; deactivating the hydraulic tensioning means, and removing the carrier from the bolt.
  • Subsequent de-tensioning of said bolt comprises the steps of: locating the carrier on the bolt,* actuating the hydraulic tensioning means to tension the bolt and to displace the nut from its operative position; rotating said nut further from its operative position; deactivating the hydraulic tensioning means; disconnecting the lower end extent of the bolt from the anchor means, and removing the carrier and the bolt located therein from the first flange.
  • the anchor means preferably comprises a segmented collet nut resiliently biased into a closed operative position and so arranged as to permit axial insertion therethrough of said lower end extent of the bolt to effect threaded engagement therewith, but requiring rotation of the bolt to remove the bolt therefrom.
  • the anchor means may be mounted on the second flange, or, alternatively, may be mounted on the carrier, means reacting between the carrier and the anchor means to enable location of the anchor means into an operative position adjacent the second flange.
  • the carrier comprises a hydraulic tensioning device incorporating reaction means mounted on the upper end extent of the bolt, the primary nut being mounted on the intermediate extent of the bolt, actuation of the tensioning device tensioning the bolt by reaction between the first flange and the reaction means, the operative position of the primary nut being in engagement with the first flange.
  • the reaction means comprises a segmented collet nut resiliently biased into an operative closed position, the internal surface of said nut and the external surface of the upper end extent of the bolt being correspondingly serrated to permit axial insertion of the upper end extent of the bolt through the closed nut, but preventing removal of the bolt from said nut other than by opening of the nut.
  • the intermediate extent of the bolt includes an abutment thereon for engagement by the primary nut on rotation thereof further away from the first flange on de-tensioning of the bolt, and whereby continued unscrewing of the primary nut results in rotation of the bolt and disconnection of the lower end extent of the bolt from the anchor means.
  • the bolt is a hydraulic bolt the head of which incorporates a hydraulic piston-cylinder arrangement for reaction against the first flange to effect tensioning of the bolt, the carrier comprising a hydraulic source for said bolt and releasable interlock means reacting between the carrier and the bolt to permit connection and disconnection of the carrier and the bolt.
  • the primary nut conveniently comprises an internally threaded retaining ring mounted on the externally threaded head of the bolt, the operative position of ring being in engagement with the first flange.
  • the head of the nut includes an abutment thereon for engagement by the retaining ring on rotation thereof further away from the first flange on de-tensioning of the bolt, and whereby continued unscrewing of the retaining ring results in rotation of the bolt and disconnection of the bolt from the anchor means.
  • the primary nut comprises a hydraulic nut including a cylinder reacting against the first flange, a piston within said cylinder, and reaction means mounted on the bolt for engagement by the piston to effect tensioning of the bolt, the carrier comprising a hydraulic source for said nut.
  • the primary nut includes an internally threaded retaining ring mounted on the piston the external surface of which is correspondingly threaded, the operative position of the primary nut being determined by abutment of the retaining ring with the cylinder.
  • the piston and the bolt are each provided with associated abutments thereon so arranged that, on rotation of the retaining ring further away from the cylinder on detensioning of the bolt, the retaining ring engages the abutment on the piston, further rotation of the retaining ring resulting in movement of the hydraulic nut into engagement with the abutment on the bolt, still further rotation of the retaining ring resulting in rotation of the bolt and disconnection of the bolt from the anchor means.
  • rotation of the primary nut/retaining ring is effected by a remote controlled motor mounted on the carrier.
  • Figs 1 to 3 show, partly in longitudinal sections, three alternative apparatus for performing the method of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
  • Fig. 1 there are shown a pair of flanges 2,4 between which a joint is to be effected, the flanges 2,4 having a series of aligned bores angularly spaced therearound for receiving therein associated bolts to effect said joint.
  • the method of the invention enables the bolts not only to be tensioned and detensioned remotely but inserted into and removed from the joint remotely.
  • a bolt to effect the joint between the flanges 2,4 is indicated generally at 6 and includes a threaded lower end extent 8, an increased-diameter annular flange 10 above said extent 8 and an upper end extent 12 of serrated configuration for reasons which will become apparent.
  • a primary nut 14 is threaded on the upper regions of the extent 8 of the bolt.
  • a hydraulic tensioning device is indicated generally at 16 and includes a cylinder 18 in which is slidably mounted a piston 20 provided with a tapering surface adapted to co-operate with a reaction device in the form of a tapered, spring-loaded collet nut 22 having a normally closed operative condition.
  • the internal surface of said nut is serrated such as to permit upward movement of the serrated extent 12 of the bolt 6, after passage through the cylinder 18 and piston 20, through the collet nut 22 with the serrations of the collet nut 22 riding over those on the bolt 6 in the manner of a ratchet.
  • the nut 22 is biased into operative engagement with the bolt 6, the configurations of the serrations on the nut 22 and the bolt 6 being such as to prevent withdrawal of the bolt 6 from within the nut 22 other than after opening of said nut 22 from its closed condition.
  • an hydraulic motor 24 driving a gearwheel 26 which meshes with a corresponding toothed formation provided around the nut 14 and such that, on actuation of the motor 24, the nut 14 is rotated on the bolt 6.
  • Anchor means in the form of a spring loaded, internally threaded collet nut 28, are mounted on the device 16 by way of a linkage enabling substantially universal manoeuvring of the position of the nut 28 relative to the device 16.
  • the linkage comprises a first arm 30 pivotally mounted at 32 to a bracket 34 on the device 16 and pivotal about the point 32 by means of a first hydraulic ram 36 reacting between the bracket 34 and the arm 30.
  • the arm 30 carries an elongate shaft 38 slidably mounted on which is a carrier 40 for the nut 28, a second hydraulic ram 42 reacting between the arm 30 and the nut 28 to locate said nut axially on the shaft 38.
  • a releasable interlock 44 is provided between the carrier 40 and the nut 28 whereby the carrier 40 can be disconnected from the nut 28 by relative axial movement therebetween.
  • the bolt 6 together with the nut 14 thereon is positioned within the tensioning device 16 by inserting the upper end extent 12 thereof through the nut 12 whereby said nut 12 retains the bolt 6 within the device 16.
  • the gearwheel 26 meshes with the nut 14, and the nut 28 is located towards the end of the shaft
  • the ram is extended to pivot the arm 30 and attached components outwardly to the right as viewed in the drawing.
  • the overall assembly is remotely moved towards the flange 2, and the extent 8 of the bolt 6 is passed through the flanges 2,4 until the device 16 seats on the flange 2. In this position of the bolt 6, the extent 8 thereof projects from the flange 4.
  • the ram 36 is actuated to bring the nut 28 into axial alignment with the bolt 6, and the ram 42 is then actuated to move the nut onto the projecting end of the bolt 6.
  • the spring-loaded nature of the nut 28 enables said nut 28 to be moved along the bolt 6 into an operative position abutting the underside of the flange
  • the tensioning device 16 is actuated to stretch the bolt 6 by reaction between the flange 2 and the nut 22, the co-operation between the extent 8 of the bolt 6 and the nut 28 preventing bodily upward movement of the bolt and anchoring the bolt in its operative position.
  • the motor 24 is actuated to screw the nut 14 down onto the flange 14 and thereby retain the bolt in its stretched condition.
  • the hydraulic pressure is released from the tensioning device 16 whereby the piston 20 no longer makes pressurised contact with the nut 22, the interlock 44 between the carrier 40 and the nut 28 is disconnected by appropriate extension of the ram 42, and the tensioning device 16 and attached components are removed from the now-tightened joint.
  • the tensioning device 16 is lowered onto the bolt 6 to seat on the flange 2 with the nut 22 engaging the upper extent 12 of the bolt 6, the gearwheel 6 is engaged with the nut 14, and the interlock 44 between the carrier 40 and the nut 28 is reconnected.
  • the tensioning device 16 is actuated to extend the bolt 6 whereby the nut 14 is unseated from the flange 2. With hydraulic pressure maintained, the motor 24 is actuated to screw the nut 14 upwardly on the bolt 6 into engagement with the flange 10. At this point, the motor 24 is arranged to stall, and hydraulic pressure is released from the device 16.
  • the bolt 6 is now loose.
  • the motor 24 is re- actuated to rotate the nut 14 upwardly.
  • rotation of the nut 14 results in rotation of the bolt 6 whereby the extent 8 of the bolt 6 is unscrewed from the nut 28, the ram 40 being extended to accommodate the upward movement of the device 16 relative to the nut 28.
  • the described method of tensioning and detensioning a bolt is such that the complete operation, including the application of the bolt to the flanges to be joined and the removal of the bolt from the flanges to be disconnected, can be done under remote control without the necessity for any manual intervention.
  • the bolt is carried by the tensioning device and can be manoeuvred into and out of the joint by appropriate remote control of the tensioning device.
  • the method of the invention is equally applicable to joints which are effected by hydraulic nuts or bolts rather than the conventional nut and bolt of Fig. 1.
  • Fig. 2 illustrates an hydraulic bolt, components equivalent to those of Fig. 1 being similarly referenced.
  • the head of the bolt 6 incorporates a piston 50 slidable in a cylinder 52 on the application thereto of hydraulic pressure, the piston 50 reacting against the flange 2 and the cylinder 52 being integral with the threaded extent 8 of the bolt 6.
  • the cylinder 52 is externally threaded and carries a retaining ring 54 which is internally threaded for rotation on the cylinder 52, and externally threaded for rotation by the gearwheel 26.
  • the cylinder 52 includes an increased diameter shoulder 56 above the retaining ring for reasons which will become apparent.
  • the bolt 6 is mounted in a carrier 58 to which it is releasably connected by a male/female interface 60 which also provides the supply of hydraulic fluid to the bolt 6.
  • An interlock 62 maintains the connection between the carrier 58 and the bolt 6.
  • the motor 24 is mounted on the carrier 58.
  • the anchor means in the form of the spring-loaded collet nut 28 is secured to the flange 4 by means of spring-loaded sleeve 64 located in the bore of the flange 4.
  • the nut 28 is permanently located on the flange 4 and is not therefore manoeuvred into position with the carrier 58.
  • the nut 28 can be located in its open position to receive the extent 8 of the bolt 6 and then closed to effect threaded engagement therewith, or it may be spring-loaded such as to permit insertion therethrough of the bolt but to prevent removal therefrom other than by unscrewing of the bolt.
  • the retaining ring is turned down by the gearwheel 26 driven by the motor 24 into engagement with the flange 2 to maintain said tension and complete the joint.
  • detensioning is the reverse of the above procedure.
  • the carrier 58 is aligned with the bolt 6 and is pushed forward to engage the interface 60 and the gearwheel 26 is engaged with the ring 54.
  • the interlock 62 is actuated to secure the carrier 58 to the bolt 6.
  • Hydraulic pressure is supplied to the bolt 6 to extend said bolt 6 and to release the retaining ring 54 from the flange 2.
  • the motor 24 is activated to unscrew the retaining ring 54 further from the flange 2 and into abutment with the shoulder 56 at which point the motor 24 stalls.
  • Hydraulic pressure is released, the bolt now being unloaded.
  • the motor 24 is re-activated to drive the ring 54 against the shoulder 56 and to turn the bolt 6 which is therefore unscrewed from the nut 28.
  • the carrier 58 together with the bolt 6 is pushed away from the joint to withdraw the bolt 6 from the bolt holes in the flanges 2,4, and the assembly is recovered. It will be appreciated that the carrier 58 may be common to a plurality of bolts 6 all of which are recovered on removal of the carrier 58 from the flange 2.
  • Fig. 3 shows a bolt 6 provided with a hydraulic nut, components equivalent to those of Figs. 1 and 2 being similarly referenced.
  • the nut indicated generally at 70, comprises a cylinder 72 seating on the flange 2 in which is slidably mounted an externally-threaded piston 74 having a tapering surface adapted to co-operate with a corresponding tapering surface of a reaction nut 76 mounted on the bolt 6.
  • An internally and externally threaded retaining ring 78 is mounted on the threaded extent of the piston 74 and is rotatable by the gearwheel 26 which meshes with the threaded exterior of the ring 78.
  • the piston 74 is provided with an increased- diameter shoulder 80 above the ring 78.
  • a carrier 82 for the bolt 6 provides a source of hydraulic fluid under pressure to the nut 70 by means of an inlet connection 84 which can be moved into and out of engagement with the nut 70 - Fig. 3 shows the connection 84 engaged with the nut 70.
  • this embodiment is the same as that of the embodiment of Fig. 2 except that, on tensioning of the bolt 6, the retaining ring 78 is screwed into engagement with the cylinder 72 to maintain tension, and, on detensioning, the retaining ring 78 initially engages the shoulder 80.
  • the piston 74 and the cylinder 72 of the nut 70 are interconnected with one another such that subsequent rotation of the ring 78 results in bodily movement of the nut 70 as a whole up the bolt 6, the connection 84 having been retracted from the nut 70.
  • the nut 70 abuts the flange 10 on the bolt 6, continued rotation of the ring 78 resulting in unscrewing of the bolt 6 from the nut 28.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Hand Tools For Fitting Together And Separating, Or Other Hand Tools (AREA)

Abstract

A method of tensioning a bolt (6) interconnecting first and second flanges (2, 4) comprises the steps of locating the bolt (6) to be tensioned in a carrier (16) incorporating hydraulic tensioning means (18, 20, 22), positioning the carrier (16) on the first flange (2) so that the lower end extent (8) of the bolt extends through the flanges (2, 4) providing anchor means (28) at or adjacent the second flange (4) into which said lower end extent (8) of the bolt (6) is received to be retained thereby, actuating the hydraulic tensioning means (18, 20, 22) to tension the bolt (6) by reaction against the first flange (2), turning a primary nut (14) carried on the bolt (6) relative to the bolt (6) into an operative position to retain said tension, deactivating the hydraulic tensioning means (18, 20, 22), and removing the carrier (16) from the bolt (6). On de-tensioning of the bolt (6), the bolt (6) is removed from the joint together with the carrier (16).

Description

A METHOD OF TENSIONING AND DE-TENSTONING A BOLT TECHNICAL FIELD
This invention relates to a method of tensioning and de-tensioning a bolt hydraulically and has particular though not exclusive application in sub-sea or other situations where access to the joint to be bolted is restricted. BACKGROUND ART
It is well established practice to tighten a bolted joint using a hydraulic tensioner which stretches the bolt after which the associated nut is screwed down into engagement with the joint face. On release of the hydraulic pressure, the bolt tries to return to its original unstretched length, which is prevented by said engagement between the nut and the joint face. So the joint is tightened.
Such a procedure is normally under manual control, and, in sub-sea situations in which the procedure is extensively used, the manual functions are carried out by divers.
However there is an increasing need to carry out bolt tightening (and loosening) at greater sub-sea depths which are impractical or impossible for divers to access . Thus the functions that would normally be carried out manually have to be effected under remote control.
Similar requirements exist in the nuclear industry where manual intervention must be kept to a minimum in order to restrict radiation exposure time.
Although actuation of the tensioning devices can readily be effected under remote control, as disclosed in, for example, US specification no. 3877326, it has heretofore been necessary to fit and remove the nuts and bolts themselves to and from the joint manually, with consequential limitations and complications to the overall procedure. DISCLOSURE OF THE INVENTION
It would be desirable to be able to provide a method of tensioning and de-tensioning a bolt which enabled the bolt to be applied to and removed from the associated joint remotely.
According to the present invention there is provided a method of tensioning a bolt interconnecting first and second flanges, the bolt carrying a primary nut to be tightened, characterised by the steps of: locating the bolt to be tensioned in a carrier incorporating hydraulic tensioning means; positioning the carrier on the first flange with the lower end extent of the bolt carried thereby extending through the flanges; providing anchor means at or adjacent the second flange into which said lower end extent of the bolt is received to be retained thereby; actuating the hydraulic tensioning means to tension the bolt by reaction against the first flange; turning the primary nut relative to the bolt into an operative position to retain said tension; deactivating the hydraulic tensioning means, and removing the carrier from the bolt. Thus it will be appreciated that, as the bolt is mounted in the carrier, there is no need for prior location of the bolt in the joint - the bolt is automatically located in position on application of the carrier to the joint, which application is preferably under remote control.
Subsequent de-tensioning of said bolt comprises the steps of: locating the carrier on the bolt,* actuating the hydraulic tensioning means to tension the bolt and to displace the nut from its operative position; rotating said nut further from its operative position; deactivating the hydraulic tensioning means; disconnecting the lower end extent of the bolt from the anchor means, and removing the carrier and the bolt located therein from the first flange.
The anchor means preferably comprises a segmented collet nut resiliently biased into a closed operative position and so arranged as to permit axial insertion therethrough of said lower end extent of the bolt to effect threaded engagement therewith, but requiring rotation of the bolt to remove the bolt therefrom. The anchor means may be mounted on the second flange, or, alternatively, may be mounted on the carrier, means reacting between the carrier and the anchor means to enable location of the anchor means into an operative position adjacent the second flange.
In one embodiment of the invention, the carrier comprises a hydraulic tensioning device incorporating reaction means mounted on the upper end extent of the bolt, the primary nut being mounted on the intermediate extent of the bolt, actuation of the tensioning device tensioning the bolt by reaction between the first flange and the reaction means, the operative position of the primary nut being in engagement with the first flange.
Conveniently the reaction means comprises a segmented collet nut resiliently biased into an operative closed position, the internal surface of said nut and the external surface of the upper end extent of the bolt being correspondingly serrated to permit axial insertion of the upper end extent of the bolt through the closed nut, but preventing removal of the bolt from said nut other than by opening of the nut.
Preferably the intermediate extent of the bolt includes an abutment thereon for engagement by the primary nut on rotation thereof further away from the first flange on de-tensioning of the bolt, and whereby continued unscrewing of the primary nut results in rotation of the bolt and disconnection of the lower end extent of the bolt from the anchor means.
In a further embodiment of the invention, the bolt is a hydraulic bolt the head of which incorporates a hydraulic piston-cylinder arrangement for reaction against the first flange to effect tensioning of the bolt, the carrier comprising a hydraulic source for said bolt and releasable interlock means reacting between the carrier and the bolt to permit connection and disconnection of the carrier and the bolt.
The primary nut conveniently comprises an internally threaded retaining ring mounted on the externally threaded head of the bolt, the operative position of ring being in engagement with the first flange.
Preferably the head of the nut includes an abutment thereon for engagement by the retaining ring on rotation thereof further away from the first flange on de-tensioning of the bolt, and whereby continued unscrewing of the retaining ring results in rotation of the bolt and disconnection of the bolt from the anchor means.
In a still further embodiment of the invention, the primary nut comprises a hydraulic nut including a cylinder reacting against the first flange, a piston within said cylinder, and reaction means mounted on the bolt for engagement by the piston to effect tensioning of the bolt, the carrier comprising a hydraulic source for said nut. Conveniently the primary nut includes an internally threaded retaining ring mounted on the piston the external surface of which is correspondingly threaded, the operative position of the primary nut being determined by abutment of the retaining ring with the cylinder.
Preferably the piston and the bolt are each provided with associated abutments thereon so arranged that, on rotation of the retaining ring further away from the cylinder on detensioning of the bolt, the retaining ring engages the abutment on the piston, further rotation of the retaining ring resulting in movement of the hydraulic nut into engagement with the abutment on the bolt, still further rotation of the retaining ring resulting in rotation of the bolt and disconnection of the bolt from the anchor means.
In all embodiments it is preferred that rotation of the primary nut/retaining ring is effected by a remote controlled motor mounted on the carrier. BRIEF DESCRIPTION OF THE DRAWINGS
Figs 1 to 3 show, partly in longitudinal sections, three alternative apparatus for performing the method of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to Fig. 1 there are shown a pair of flanges 2,4 between which a joint is to be effected, the flanges 2,4 having a series of aligned bores angularly spaced therearound for receiving therein associated bolts to effect said joint.
The method of the invention enables the bolts not only to be tensioned and detensioned remotely but inserted into and removed from the joint remotely.
A bolt to effect the joint between the flanges 2,4 is indicated generally at 6 and includes a threaded lower end extent 8, an increased-diameter annular flange 10 above said extent 8 and an upper end extent 12 of serrated configuration for reasons which will become apparent.
A primary nut 14 is threaded on the upper regions of the extent 8 of the bolt.
A hydraulic tensioning device is indicated generally at 16 and includes a cylinder 18 in which is slidably mounted a piston 20 provided with a tapering surface adapted to co-operate with a reaction device in the form of a tapered, spring-loaded collet nut 22 having a normally closed operative condition. The internal surface of said nut is serrated such as to permit upward movement of the serrated extent 12 of the bolt 6, after passage through the cylinder 18 and piston 20, through the collet nut 22 with the serrations of the collet nut 22 riding over those on the bolt 6 in the manner of a ratchet. The nut 22 is biased into operative engagement with the bolt 6, the configurations of the serrations on the nut 22 and the bolt 6 being such as to prevent withdrawal of the bolt 6 from within the nut 22 other than after opening of said nut 22 from its closed condition.
Mounted on the device 16 is an hydraulic motor 24 driving a gearwheel 26 which meshes with a corresponding toothed formation provided around the nut 14 and such that, on actuation of the motor 24, the nut 14 is rotated on the bolt 6.
Anchor means in the form of a spring loaded, internally threaded collet nut 28, are mounted on the device 16 by way of a linkage enabling substantially universal manoeuvring of the position of the nut 28 relative to the device 16.
More particularly, the linkage comprises a first arm 30 pivotally mounted at 32 to a bracket 34 on the device 16 and pivotal about the point 32 by means of a first hydraulic ram 36 reacting between the bracket 34 and the arm 30.
The arm 30 carries an elongate shaft 38 slidably mounted on which is a carrier 40 for the nut 28, a second hydraulic ram 42 reacting between the arm 30 and the nut 28 to locate said nut axially on the shaft 38. A releasable interlock 44 is provided between the carrier 40 and the nut 28 whereby the carrier 40 can be disconnected from the nut 28 by relative axial movement therebetween.
Interconnection of the flanges 2,4 to effect a tight joint therebetween by means of the bolt 6 is achieved as follows.
The bolt 6 together with the nut 14 thereon is positioned within the tensioning device 16 by inserting the upper end extent 12 thereof through the nut 12 whereby said nut 12 retains the bolt 6 within the device 16. The gearwheel 26 meshes with the nut 14, and the nut 28 is located towards the end of the shaft
38 remote from the arm 30. The ram is extended to pivot the arm 30 and attached components outwardly to the right as viewed in the drawing.
The overall assembly is remotely moved towards the flange 2, and the extent 8 of the bolt 6 is passed through the flanges 2,4 until the device 16 seats on the flange 2. In this position of the bolt 6, the extent 8 thereof projects from the flange 4.
The ram 36 is actuated to bring the nut 28 into axial alignment with the bolt 6, and the ram 42 is then actuated to move the nut onto the projecting end of the bolt 6. The spring-loaded nature of the nut 28 enables said nut 28 to be moved along the bolt 6 into an operative position abutting the underside of the flange
4 and in threaded engagement with the bolt 6.
The tensioning device 16 is actuated to stretch the bolt 6 by reaction between the flange 2 and the nut 22, the co-operation between the extent 8 of the bolt 6 and the nut 28 preventing bodily upward movement of the bolt and anchoring the bolt in its operative position.
The motor 24 is actuated to screw the nut 14 down onto the flange 14 and thereby retain the bolt in its stretched condition. The hydraulic pressure is released from the tensioning device 16 whereby the piston 20 no longer makes pressurised contact with the nut 22, the interlock 44 between the carrier 40 and the nut 28 is disconnected by appropriate extension of the ram 42, and the tensioning device 16 and attached components are removed from the now-tightened joint.
Detensioning and removal of the bolt 6 is achieved as follows.
The tensioning device 16 is lowered onto the bolt 6 to seat on the flange 2 with the nut 22 engaging the upper extent 12 of the bolt 6, the gearwheel 6 is engaged with the nut 14, and the interlock 44 between the carrier 40 and the nut 28 is reconnected.
The tensioning device 16 is actuated to extend the bolt 6 whereby the nut 14 is unseated from the flange 2. With hydraulic pressure maintained, the motor 24 is actuated to screw the nut 14 upwardly on the bolt 6 into engagement with the flange 10. At this point, the motor 24 is arranged to stall, and hydraulic pressure is released from the device 16.
The bolt 6 is now loose. The motor 24 is re- actuated to rotate the nut 14 upwardly. However, because of abutment of the nut 14 with the flange 10, rotation of the nut 14 results in rotation of the bolt 6 whereby the extent 8 of the bolt 6 is unscrewed from the nut 28, the ram 40 being extended to accommodate the upward movement of the device 16 relative to the nut 28. Once the bolt 6 is free from the nut 28, the complete assembly together with the bolt can be retrieved.
Thus it will be appreciated that the described method of tensioning and detensioning a bolt is such that the complete operation, including the application of the bolt to the flanges to be joined and the removal of the bolt from the flanges to be disconnected, can be done under remote control without the necessity for any manual intervention. At all times during application and removal, the bolt is carried by the tensioning device and can be manoeuvred into and out of the joint by appropriate remote control of the tensioning device.
The method of the invention is equally applicable to joints which are effected by hydraulic nuts or bolts rather than the conventional nut and bolt of Fig. 1.
Fig. 2 illustrates an hydraulic bolt, components equivalent to those of Fig. 1 being similarly referenced.
The head of the bolt 6 incorporates a piston 50 slidable in a cylinder 52 on the application thereto of hydraulic pressure, the piston 50 reacting against the flange 2 and the cylinder 52 being integral with the threaded extent 8 of the bolt 6.
The cylinder 52 is externally threaded and carries a retaining ring 54 which is internally threaded for rotation on the cylinder 52, and externally threaded for rotation by the gearwheel 26. The cylinder 52 includes an increased diameter shoulder 56 above the retaining ring for reasons which will become apparent.
The bolt 6 is mounted in a carrier 58 to which it is releasably connected by a male/female interface 60 which also provides the supply of hydraulic fluid to the bolt 6. An interlock 62 maintains the connection between the carrier 58 and the bolt 6. The motor 24 is mounted on the carrier 58.
The anchor means in the form of the spring-loaded collet nut 28 is secured to the flange 4 by means of spring-loaded sleeve 64 located in the bore of the flange 4.
The procedure for tightening the joint between the flanges 2 and 4 using the hydraulic bolt 6 is substantially the same as that detailed above in respect of the embodiment of Fig. 1, and only the differences will be detailed.
The nut 28 is permanently located on the flange 4 and is not therefore manoeuvred into position with the carrier 58. The nut 28 can be located in its open position to receive the extent 8 of the bolt 6 and then closed to effect threaded engagement therewith, or it may be spring-loaded such as to permit insertion therethrough of the bolt but to prevent removal therefrom other than by unscrewing of the bolt.
Once the bolt 6 is tensioned by the application of hydraulic fluid under pressure to the chamber between the piston 50 and the cylinder 52, the retaining ring is turned down by the gearwheel 26 driven by the motor 24 into engagement with the flange 2 to maintain said tension and complete the joint.
The hydraulic pressure is then released, the interlock 62 is released, the carrier 58 and associated components are disengaged at the interface 60 from the bolt 6, and the assembly is removed from the flange 2.
As before, detensioning is the reverse of the above procedure. The carrier 58 is aligned with the bolt 6 and is pushed forward to engage the interface 60 and the gearwheel 26 is engaged with the ring 54. The interlock 62 is actuated to secure the carrier 58 to the bolt 6.
Hydraulic pressure is supplied to the bolt 6 to extend said bolt 6 and to release the retaining ring 54 from the flange 2. The motor 24 is activated to unscrew the retaining ring 54 further from the flange 2 and into abutment with the shoulder 56 at which point the motor 24 stalls.
Hydraulic pressure is released, the bolt now being unloaded. The motor 24 is re-activated to drive the ring 54 against the shoulder 56 and to turn the bolt 6 which is therefore unscrewed from the nut 28.
Once the bolt 6 is free from the nut 28, the carrier 58 together with the bolt 6 is pushed away from the joint to withdraw the bolt 6 from the bolt holes in the flanges 2,4, and the assembly is recovered. It will be appreciated that the carrier 58 may be common to a plurality of bolts 6 all of which are recovered on removal of the carrier 58 from the flange 2.
Fig. 3 shows a bolt 6 provided with a hydraulic nut, components equivalent to those of Figs. 1 and 2 being similarly referenced.
The nut, indicated generally at 70, comprises a cylinder 72 seating on the flange 2 in which is slidably mounted an externally-threaded piston 74 having a tapering surface adapted to co-operate with a corresponding tapering surface of a reaction nut 76 mounted on the bolt 6.
An internally and externally threaded retaining ring 78 is mounted on the threaded extent of the piston 74 and is rotatable by the gearwheel 26 which meshes with the threaded exterior of the ring 78.
The piston 74 is provided with an increased- diameter shoulder 80 above the ring 78.
A carrier 82 for the bolt 6 provides a source of hydraulic fluid under pressure to the nut 70 by means of an inlet connection 84 which can be moved into and out of engagement with the nut 70 - Fig. 3 shows the connection 84 engaged with the nut 70.
The operation of this embodiment is the same as that of the embodiment of Fig. 2 except that, on tensioning of the bolt 6, the retaining ring 78 is screwed into engagement with the cylinder 72 to maintain tension, and, on detensioning, the retaining ring 78 initially engages the shoulder 80. The piston 74 and the cylinder 72 of the nut 70 are interconnected with one another such that subsequent rotation of the ring 78 results in bodily movement of the nut 70 as a whole up the bolt 6, the connection 84 having been retracted from the nut 70. Thus the nut 70 abuts the flange 10 on the bolt 6, continued rotation of the ring 78 resulting in unscrewing of the bolt 6 from the nut 28.

Claims

1. A method of tensioning a bolt (6) interconnecting first and second flanges (2,4) , the bolt (6) carrying a primary nut (14) to be tightened, characterised by the steps of : locating the bolt (6) to be tensioned in a carrier (16) incorporating hydraulic tensioning means (18,20,22) ; positioning the carrier (16) on the first flange (2) with the lower end extent (8) of the bolt carried thereby extending through the flanges (2,4) ; providing anchor means (28) at or adjacent the second flange (4) into which said lower end extent (8) of the bolt (6) is received to be retained thereby; actuating the hydraulic tensioning means (18,20,22) to tension the bolt (6) by reaction against the first flange (2) ; turning the primary nut (14) relative to the bolt (6) into an operative position to retain said tension; deactivating the hydraulic tensioning means (18,20,22) , and removing the carrier (16) from the bolt (6) .
2. A method of detensioning a bolt (6) previously tensioned according to the method of claim 1 comprises the steps of: locating the carrier (16) on the bolt (6) ,* actuating the hydraulic tensioning means (18,20,22) to tension the bolt (6) and to displace the nut (14) from its operative position; rotating said nut (14) further from its operative position; deactivating the hydraulic tensioning means (18,20,22) ; disconnecting the lower end extent (8) of the bolt (6) from the anchor means (28) , and removing the carrier (16) and the bolt (6) located therein from the first flange (2) .
3. A method as claimed in claim 1 or claim 2 in which the anchor means comprises a segmented collet nut
(28) resiliently biased into a closed operative position and so arranged as to permit axial insertion therethrough of said lower end extent (8) of the bolt
(6) to effect threaded engagement therewith, but requiring rotation of the bolt (6) to remove the bolt
(6) therefrom.
4. A method as claimed in any one of claims 1 to 3 and comprising the step of mounting the anchor means (28) on the second flange (4) .
5. A method as claimed in any one of claims 1 to 3 in which the anchor means (28) are mounted on the carrier (16) , means (30 to 44) reacting between the carrier (16) and the anchor means (28) , the method comprising the step of actuating said means (30 to 44) to locate the anchor means (28) in an operative position adjacent the second flange (4) .
6. A method as claimed in any one of claims 1 to 5 in which the carrier comprises a hydraulic tensioning device (16) incorporating reaction means (22) mounted on the upper end extent (12) of the bolt (6) , the primary nut (14) being mounted on the intermediate extent of the bolt (6) , actuation of the tensioning device (16) tensioning the bolt (6) by reaction between the first flange (2) and the reaction means (22) , the operative position of the primary nut (14) being in engagement with the first flange (2) .
7. A method as claimed in claim 6 in which the reaction means comprises a segmented collet nut (22) resiliently biased into an operative closed position, the internal surface of said nut (22) and the external surface of the upper end extent (12) of the bolt (6) being correspondingly serrated to permit axial insertion of the upper end extent (12) of the bolt (6) through the closed nut (22) , but preventing removal of the bolt (6) from said nut (22) other than by opening of the nut (22) .
8. A method as claimed in claim 6 or claim 7 in which the intermediate extent of the bolt (6) includes an abutment (10) thereon for engagement by the primary nut (14) on rotation thereof further away from the first flange (2) on de-tensioning of the bolt (6) , and whereby continued unscrewing of the primary nut (14) results in rotation of the bolt (6) and disconnection of the lower end extent (8) of the bolt (6) from the anchor means (28) .
9. A method as claimed in any one of claims 1 to 5 in which the bolt (6) is a hydraulic bolt the head of which incorporates a hydraulic piston-cylinder arrangement (50,52) for reaction against the first flange (2) to effect tensioning of the bolt (6) , the carrier (58) comprising a hydraulic source for said bolt (6) and releasable interlock means (62) reacting between the carrier (58) and the bolt (6) to permit connection and disconnection of the carrier (58) and the bolt (6) .
10. A method as claimed in claim 9 in which the primary nut comprises an internally threaded retaining ring (54) mounted on the externally threaded head of the bolt (6) , the operative position of ring (54) being in engagement with the first flange (2) .
11. A method as claimed in claim 10 in which the head of the nut (6) includes an abutment (56) thereon for engagement by the retaining ring (54) on rotation thereof further away from the first flange (2) on de¬ tensioning of the bolt (6) , and whereby continued unscrewing of the retaining ring (54) results in rotation of the bolt (6) and disconnection of the bolt
(6) from the anchor means (28) .
12. A method as claimed in any one of claims 1 to 5 in which the primary nut comprises a hydraulic nut
(70) including a cylinder (72) reacting against the first flange (2) , a piston (74) within said cylinder
(72) , and reaction means (76) mounted on the bolt (6) for engagement by the piston (74) to effect tensioning of the bolt (6), the carrier (82) comprising a hydraulic source for said nut (70) .
13. A method as claimed in claim 12 in which the primary nut (70) includes an internally threaded retaining ring (78) mounted on the piston (74) the external surface of which is correspondingly threaded, the operative position of the primary nut (70) being determined by abutment of the retaining ring (78) with the cylinder (72) .
14. A method as claimed in claim 13 in which the piston (74) and the bolt (6) are each provided with associated abutments (80,10) thereon so arranged that, on rotation of the retaining ring (78) further away from the cylinder (72) on detensioning of the bolt (6) , the retaining ring (78) engages the abutment (80) on the piston (74) , further rotation of the retaining ring (78) resulting in movement of the hydraulic nut (70) into engagement with the abutment (10) on the bolt (6) , still further rotation of the retaining ring (78) resulting in rotation of the bolt (6) and disconnection of the bolt (6) from the anchor means (28) .
15. A method as claimed in any one of claims 1 to 14 in which rotation of the primary nut/retaining ring (14,54,78) is effected by a remote controlled motor (24) mounted on the carrier (16,58,82) .
PCT/GB1995/001265 1994-06-07 1995-06-01 A method of tensioning and de-tensioning a bolt WO1995033598A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU26232/95A AU2623295A (en) 1994-06-07 1995-06-01 A method of tensioning and de-tensioning a bolt

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9411384A GB9411384D0 (en) 1994-06-07 1994-06-07 Method of tensioning and de-tensioning a bolt
GB9411384.2 1994-06-07

Publications (1)

Publication Number Publication Date
WO1995033598A1 true WO1995033598A1 (en) 1995-12-14

Family

ID=10756328

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1995/001265 WO1995033598A1 (en) 1994-06-07 1995-06-01 A method of tensioning and de-tensioning a bolt

Country Status (4)

Country Link
AU (1) AU2623295A (en)
GB (1) GB9411384D0 (en)
WO (1) WO1995033598A1 (en)
ZA (1) ZA954701B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0791434A1 (en) * 1996-02-23 1997-08-27 Kabushiki Kaisha Kyoei Seiko Clamping apparatus with a gear reducer
WO1998026899A1 (en) * 1996-12-16 1998-06-25 Siemens Westinghouse Power Corporation An axial tensioned bolting system and method thereof
WO2015135998A1 (en) * 2014-03-13 2015-09-17 Airbus Defence And Space Sas Bolted connection
EP3404221A1 (en) * 2017-05-17 2018-11-21 General Electric Company Turbomachine service apparatus and related method
EP3546116A1 (en) * 2018-03-29 2019-10-02 Hohmann, Jörg Device for tightening screw joints

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1575230A1 (en) * 1965-11-08 1969-11-27 P & O Pilgrim Valve Ltd Device for generating tension in the screw bolt or the like of a screw connection
FR2495259A1 (en) * 1980-12-02 1982-06-04 Kloeckner Werke Ag Clamping mechanism for bolts on pressure vessel or boiler - esp. for safe clamping of cover on boiler, includes jack to move coupling sleeves
EP0203003A1 (en) * 1985-05-17 1986-11-26 Institut Français du Pétrole Remotely-controlled assembling device for two items
DE3533257C1 (en) * 1985-09-18 1987-01-29 Wiederaufarbeitung Von Kernbre Remotely manipulatable holding and positioning device for the nuts, arranged on the rear side of a fixed flange, of a pipeline flanged joint capable of being screwed by remote manipulation
WO1987006664A1 (en) * 1986-05-01 1987-11-05 Fullerton Robert L Quick acting speednut and spring therefor
DE3733243A1 (en) * 1986-10-01 1988-04-14 Toshiba Kawasaki Kk CONNECTING BOLT AND METHOD FOR ADJUSTING THE TENSIONING TENSION OF THE CONNECTING BOLT

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1575230A1 (en) * 1965-11-08 1969-11-27 P & O Pilgrim Valve Ltd Device for generating tension in the screw bolt or the like of a screw connection
FR2495259A1 (en) * 1980-12-02 1982-06-04 Kloeckner Werke Ag Clamping mechanism for bolts on pressure vessel or boiler - esp. for safe clamping of cover on boiler, includes jack to move coupling sleeves
EP0203003A1 (en) * 1985-05-17 1986-11-26 Institut Français du Pétrole Remotely-controlled assembling device for two items
DE3533257C1 (en) * 1985-09-18 1987-01-29 Wiederaufarbeitung Von Kernbre Remotely manipulatable holding and positioning device for the nuts, arranged on the rear side of a fixed flange, of a pipeline flanged joint capable of being screwed by remote manipulation
WO1987006664A1 (en) * 1986-05-01 1987-11-05 Fullerton Robert L Quick acting speednut and spring therefor
DE3733243A1 (en) * 1986-10-01 1988-04-14 Toshiba Kawasaki Kk CONNECTING BOLT AND METHOD FOR ADJUSTING THE TENSIONING TENSION OF THE CONNECTING BOLT

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0791434A1 (en) * 1996-02-23 1997-08-27 Kabushiki Kaisha Kyoei Seiko Clamping apparatus with a gear reducer
WO1998026899A1 (en) * 1996-12-16 1998-06-25 Siemens Westinghouse Power Corporation An axial tensioned bolting system and method thereof
US5927157A (en) * 1996-12-16 1999-07-27 Siemens Westinghouse Power Corporation Axial tensioned bolting system and method thereof
WO2015135998A1 (en) * 2014-03-13 2015-09-17 Airbus Defence And Space Sas Bolted connection
US10233958B2 (en) 2014-03-13 2019-03-19 Airbus Safran Launchers Sas Bolted connection
EP3404221A1 (en) * 2017-05-17 2018-11-21 General Electric Company Turbomachine service apparatus and related method
US20180333812A1 (en) * 2017-05-17 2018-11-22 General Electric Company Turbomachine service apparatus and related method
JP2019011752A (en) * 2017-05-17 2019-01-24 ゼネラル・エレクトリック・カンパニイ Turbo machine service apparatus and related method
US10632577B2 (en) 2017-05-17 2020-04-28 General Electric Company Turbomachine service apparatus and related method
JP7154819B2 (en) 2017-05-17 2022-10-18 ゼネラル・エレクトリック・カンパニイ Turbomachinery service equipment and related methods
EP3546116A1 (en) * 2018-03-29 2019-10-02 Hohmann, Jörg Device for tightening screw joints
EP3546116B1 (en) 2018-03-29 2020-10-14 Hohmann, Jörg Device for tightening screw joints

Also Published As

Publication number Publication date
GB9411384D0 (en) 1994-07-27
AU2623295A (en) 1996-01-04
ZA954701B (en) 1996-01-29

Similar Documents

Publication Publication Date Title
US7757366B2 (en) Coupling for connecting tubes with a nut-runner
US5253967A (en) Adapter assembly for tensioning threaded fasteners and method of tensioning threaded fasteners
EP1755832B1 (en) Improvements to hydraulic tensioning jacks
US4341406A (en) Pipe coupling comprising a chain collar
US8328482B2 (en) Hydraulic foundation bolt tensioner
US12023766B2 (en) Hydraulic tensioning and release tool for expansion fasteners
EP1971787B1 (en) Self locking tensioner
US4239266A (en) Pipe connector apparatus
US11187350B2 (en) Subsea flange tool
JPH04505501A (en) tightening device
WO2011097653A1 (en) Apparatus and methods for tightening threaded fasteners
WO1995033598A1 (en) A method of tensioning and de-tensioning a bolt
US6050156A (en) Braking mechanism for power tongs
WO1997015773A1 (en) Method and apparatus for assembling or disassembling an installation present on a seabed
EP0655025B1 (en) Mechanical tensioner
US8650990B2 (en) Hand-operated hydraulic wrench for high torque tightening and loosening
US5878490A (en) Method for connecting piping system components with limited clearance for stud tensioner
GB2201745A (en) Bolt tensioning apparatus
US4118849A (en) Fastener with removable pintail and locking collet
WO2000035637A1 (en) Hydraulic bolt tensioner
GB2272265A (en) Guide device for hose ends
GB2124119A (en) A hydraulic bolt tensioning tool with power drive for rotating a nut
JPH11129161A (en) Torque wrench device
NO325774B1 (en) Mounting device adapted for remote controlled mounting and disassembly, as well as methods for mounting and disassembling the mounting device
AU2005254122A1 (en) Improvements to hydraulic tensioning jacks

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AM AT AU BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IS JP KE KG KP KR KZ LK LR LT LU LV MD MG MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TT UA UG US UZ VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE MW SD SZ UG AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA