WO2015123727A1

WO2015123727A1 - Tube connector

Info

Publication number: WO2015123727A1
Application number: PCT/AU2015/050058
Authority: WO
Inventors: Peter PANNEKOEK
Original assignee: Swivelpole Patent Pty Ltd
Priority date: 2014-02-18
Filing date: 2015-02-17
Publication date: 2015-08-27

Abstract

A tube connector connects a tube to another structure. The connector includes a generally cylindrical resilient grasping member and a frusto- conical force distributing member. The application of an axial force to the force distributing member deforms the grasping member around the tube.

Description

"TUBE CONNECTOR"

Field of the Invention

[0001 ] The present invention relates to the connection of a tube, such as a light pole portion or a pipe, to either another tube or to a tube joint. It has been devised to work in conjunction with a Swivelpole™ joint, however is considered to have wider application.

Background to the Invention

[0002] The Swivelpole™ joint, such as described in International Patent application number PCT/AUOO/01208, allows for the relative rotation of two pole sections about an axis of rotation. It is particularly useful in the maintenance of light poles, where one pole section can be fixed to the ground, and the other allowed to rotate in order for maintenance to be conducted on a raised light fixture.

[0003] The Swivelpole™ joint can be deployed in two ways: with custom designed light pole sections extending to the ground and to the light fixture; and with a separate joint arranged to connect to generic light pole sections.

[0004] The present invention proposes a connector which can be used to connect a generic light pole section to a Swivelpole™ joint. Advantages of the present invention, and other potential uses, will be apparent from the description below.

Summary of the Invention

[0005] According to a first aspect of the present invention there is provided a connector for connecting a tube to another structure, the connector including a generally rigid fixed portion having a bore, a grasping member which is generally cylindrical in shape; a force distributing member and a collar;

the force distributing member having a generally frusto-conical inner surface, arranged to cooperate with the grasping member and/or the tube; the force distributing member having a generally frusto-conical outer surface, arranged to cooperate with the collar; and

means for connecting the collar to the fixed portion such that a generally axial load can be applied to the force distributing member by the collar;

wherein

a sufficient axial force applied to the force distributing member will cause the force distributing member to deform and thereby frictionally engage a tube located inside the internal wall of the grasping member.

[0006] Preferably the force distributing member is a split ring member.

[0007] According to a second aspect of the present invention there is provided a connector for connecting a tube to another structure, the connector including a generally rigid fixed portion having a bore, a grasping member which is generally cylindrical in shape; and a force distributing member;

the grasping member having an inner end and an outer end;

the grasping member having a generally cylindrical internal wall extending from the inner end to the outer end;

the grasping member having an outer wall with two portions: a first portion which is generally cylindrical and extends from the inner end to a step; and a second portion which is generally frusto-conical, and extends from the outer end to the step, with the diameter increasing between the outer end and the step;

the first portion of the grasping member outer wall being sized so as to be received by the bore of the fixed portion in a sliding fit;

the step having a greater diameter than the bore of the fixed portion; the force distributing member having a generally frusto-conical inner surface, arranged to cooperate with the second portion of the grasping member outer wall; and

means for connecting the force distributing member to the fixed portion such that a generally axial load can be applied to the force distributing member; wherein

a sufficient axial force applied to the force distributing member will cause the second portion of the grasping member to deform and thereby frictionally engage a tube located inside the internal wall of the grasping member.

[0008] Preferably, the grasping member is a single contiguous member.

[0009] It is preferred that the axial force applied to the force distributing member is arranged to compress the grasping member, causing lateral expansion or bulging.

[0010] It is preferred that the fixed portion and the force distributing member are made out of a generally rigid first material, and the grasping member is made out of a relatively deformable second material. The grasping member is preferably formed from a material having a Poisson's ratio greater than 0.4. In a preferred embodiment, that fixed portion and the force distributing member are made from a metal such as steel, and the grasping member is made from a polymer material such as a urethane. Advantageously, the deformation of the grasping member acts to seal the bore of fixed portion, preventing water ingress.

[001 1 ] The grasping member may have a tube restraint at an inner end thereof. The tube restraint may be formed by an internal step at the inner end of the grasping member. Alternatively, it may be formed by a closing of the grasping member at the inner end.

[0012] In an alternative arrangement, the fixed portion may include an internal shoulder arranged to receive an inner end of a tube.

[0013] The internal wall of the grasping member may include friction- increasing markings. In a preferred embodiment of the invention, these markings comprise circular grooves axially spaced along the internal wall. [0014] The means for connecting the force distributing member to the fixed portion may include an internally threaded collar arranged to locate about the force distributing member, the collar being arranged to engage with an external thread at an outer end of the fixed member, such that rotation of the collar about the threaded engagement translates into axial movement of the force distributing member.

[0015] In this embodiment, the force distributing member may have a generally frusto-conical outer surface, arranged to bear against a generally frusto-conical internal shoulder of the collar. The frusto-conical outer surface may be parallel to the frusto-conical inner surface of the force distributing member.

[0016] Alternatively, the fixed portion may include a shoulder at an outer end thereof, arranged to receive a base annulus of the force distributing member. The force distributing member may include generally axial apertures spaced about its periphery, and arranged to align with generally axial apertures spaced about the periphery of the shoulder. The means for connecting the force distributing member to the fixed portion may include bolts arranged to pass through aligned general axial apertures of the force distributing member and fixed portion.

[0017] It is preferred that the shoulder of the fixed portion and the base radius of the force distributing member are tapered with respect to the axial direction. This assists in allowing water within the connector to run off.

[0018] In a preferred form of this embodiment, the generally axial apertures of the fixed portion are internally threaded, so as to allow the bolts to be tightened therein and thus a generally axial force to be applied. Alternatively, the bolts may include nuts located on an inner side of the shoulder, in use.

[0019] In the preferred form of this embodiment three bolts are spaced at 120° intervals about the force distributing member. [0020] The connector may include a secondary fixing means. It is preferred that the secondary fixing means operates in a radial direction. The

secondary fixing means may include at least one bolt receivable in a threaded aperture within the fixed portion, such that rotation of the bolt causes movement of the bolt in a radial direction into the bore of the fixed portion.

[0021 ] The bolts of the secondary fixing means may act against the first portion of the grasping member.

[0022] In a preferred embodiment of the invention the secondary fixing means includes two circumferentially spaced bolts.

Brief Description of the Drawings

[0023] It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:

[0024] Figure 1 is a perspective of a view of a Swivelpole™ joint having an upper end and a lower end, each end having a connector in accordance with a first embodiment of the present invention;

[0025] Figure 2 is an exploded view of a connector at the upper end of the joint of Figure 1 ;

[0026] Figure 3 is a partially cut-away view of the connector of Figure 2 when assembled;

[0027] Figure 4 is a cross section through the connector of Figure 2 when assembled;

[0028] Figure 5 is a force distributing member within the connector of Figure

2; [0029] Figure 6 is a grasping member within the connector of Figure 2;

[0030] Figure 7 is a collar within the connector of Figure 2;

[0031 ] Figure 8 is an exploded view of a connector in accordance with a second embodiment of the present invention;

[0032] Figure 9 is an assembled view of an alternative Swivelpole™ joint having two of the connectors of Figure 8 associated therewith, one at either end;

[0033] Figure 10 is an under view of a grasping member within the connector of Figure 8;

[0034] Figure 1 1 is an under view of a force distributing member within the connector of Figure 8; and

[0035] Figure 12 is an exploded view of the connector of Figure 8, shown from another side.

Detailed Description of Preferred Embodiments

[0036] Referring to Figures 1 to 7, Figure 1 shows a Swivelpole™ joint 10 arranged to be connected to a lower fixed tube section (not shown) and an upper moveable tube section (not shown), such as one to which a light assembly is mounted.

[0037] The Swivelpole™ joint 10 in the configuration shown has two connectors 20 for connecting tubes to the Swivelpole™ joint 10: one connector 20 oriented upwardly for connection to the upper moveable tube section, and one connector 20' oriented downwardly for connection to the lower fixed tube section.

[0038] The upwardly oriented connector 20 will now be described with reference to the Figures. It will be appreciated that the downwardly oriented connector 20' is constructed in the same fashion, with merely the

orientations of the components being reversed.

[0039] The connector 20 is shown in an exploded view in Figure 2. It includes four principal components: a fixed portion 22, a grasping member 24, a force distributing member 26 and a collar 28.

[0040] The fixed portion 22 in this embodiment forms part of the

Swivelpole™ joint 10, and is made from the same material (generally steel or other rigid metal). The fixed portion 22 is generally cylindrical in shape, with a hollow bore 30. The hollow bore 30 has an internal diameter slightly greater than the external diameter of the tube which is to be received therein.

[0041 ] The fixed portion 22 has an inner end at the Swivelpole™ joint 10, and an outer end 32 spaced from the Swivelpole™ joint 10.

[0042] The fixed portion 22 includes an annular shoulder 36 spaced from the outer end 32. The annular shoulder 36 extends around the fixed portion 22, and has a thickness similar to that of the fixed portion 22. The effect is to create a ring having a wall thickness about twice that of the remainder of the fixed portion 22.

[0043] The fixed portion 22 has an external thread 34 between the outer end 32 and the annular shoulder 36.

[0044] The grasping member 24 is formed from a pliable material, which may be a plastic material such as a urethane, or a rubber. The material is one with a Poisson's ratio close to 0.5, with a ratio of 0.4 and above considered useful. The grasping member 24 is generally hollow cylindrical in shape, with an internal wall 40 and an outer wall 42. The grasping member 24 extends in an axial direction from an inner or lower end 44 to an outer or upper end 46. [0045] The internal wall 40 is generally cylindrical, and is sized to receive a tube portion (not shown) in a sliding fit.

[0046] The outer wall 42 has two portions: a generally cylindrical first portion 48 and a frusto-conical second portion 50. The two portions are separated at a step 52, located about two thirds of the way from the lower end 44 to the upper end 46.

[0047] The first portion 48 extends from the lower end 44 to the step 52. It has a diameter generally equal to the internal diameter of the bore 30, such that it can be received in the bore 30 in an easy sliding fit.

[0048] The second portion 50 extends from the upper end 46 to the step 52, increasing in diameter from the upper end 46 to the step 52. It has a diameter at the upper end 46 about the same as that of the first portion 48, and a diameter at the step 52 about midway between the inner and outer diameters of the fixed portion 22.

[0049] It will be thus appreciated that the grasping member 24 can be located such that its first portion 48 sits inside the bore 30, with the step 52 resting on the outer end 32 of the fixed portion 22, and its second portion 50 protruding above the outer end 32 of the fixed portion 22.

[0050] The force distributing member 26 is generally frusto-conical in shape, with an internal wall 60, and an external wall 62. The frusto-conical shapes of the internal wall 60 and the external wall 62 are parallel, and axially spaced. This is can be seen in cross section in Figure 4. This means that both the internal wall 60 and the external wall 62 have two sections: a generally cylindrical section 64 which provides the axial spacing, and a frusto-conical section 66. The arrangement is such that the frusto-conical section 66 of the internal wall 60 is arranged to locate, in use, about the second portion 50 of the grasping member 24. The frusto-conical section 66 has a similar cone angle to that of the second portion 50 of the grasping member 24. The cylindrical section 64 extends axially away, remote from the grasping member 24.

[0051 ] By way of contrast, the cylindrical section 64 of the external wall 62 is arranged to locate outside the second portion 50 of the grasping member 24, with the frusto-conical section 66 of the external wall 62 being spaced from the step 52.

[0052] The force distributing member 26 includes an axially aligned gap 68, allowing for small variation in the circumference of the force distributing member 26 under load. The force distributing member 26 may be described as a split-ring.

[0053] The collar 28 is generally hollow cylindrical in shape, with a generally cylindrical outer surface 70. The collar 28 has an inner surface having two sections: a first section 72 which is generally cylindrical and internally threaded, and a generally frusto-conical second section 74. The second section 74 has a similar cone angle to that of the frusto-conical section 66 of the external wall 62 of the force distributing member 26. The first section 72 has an internal diameter sized such that its thread is able to engage with the external thread 34 of the fixed portion 22.

[0054] In use, the connector 20 is arranged as shown in Figure 3, such that the first portion 48 of the grasping member 24 is located in the bore 30 of the fixed portion 22; the force distributing member 26 is located about the second portion 50 of the grasping member 24, and the collar 28 is located about the force distributing member 26 and engaged with the thread 34 of the fixed portion 22.

[0055] A tube section can then be located in the connector 20, being received within the grasping member 24 and the force distributing member 26. As can be seen in Figure 4, the bore 30 has an internal step 31 which will prevent the tube section from falling through the connector 20 and will maintain it loosely in position. [0056] The collar 28 can then be tightened by rotational movement along the thread 34.

[0057] The frusto-conical section 74 of the collar 28 bears against the frusto-conical section 66 of the external wall 62 of the force distributing member. This provides a wedging action against the force distributing member 26, urging it into contact with the tube section.

[0058] Simultaneously, the frusto-conical section 66 of the internal wall 60 of the force distributing member 26 bears against the second portion 50 of the grasping member 24. This results in deformation of the grasping member 24, as it is squeezed against the tube section.

[0059] The tube section is thus held in place by friction, both metal-to-metal friction between the force distributing member 26 and the tube section, and friction applied by bulging of the urethane of the grasping member 24.

[0060] It will be appreciated that the more the collar 28 is tightened, the more the force distributing member 26 and the grasping member 24 will deform and the greater will be the frictional force holding the tube section in position. Friction may be further increased by suitable finishing of the internal wall 40 of the grasping member 24, such as by the scoring of rings 82 in the internal wall.

[0061 ] In addition, it will be noted that the deformation of the grasping member 24 creates a water-proof seal within the connector 20.

[0062] The connector 20 includes a secondary fixing means. The secondary fixing means is provided by two secondary bolts 90 which are received in internally threaded secondary bolt-receiving apertures 92 radially oriented through the annular shoulder 36 of the fixed portion 22. When the tube section has been fixed in position using the means described above, it can be further secured by the tightening of the secondary bolts 90, such that their outer ends 94 bear against the tube section. [0063] A second embodiment of the present invention is shown in Figures 8 to 12. These figures show an alternative Swivelpole™ joint 1 10 arranged to be connected to a lower fixed tube section (not shown) and an upper moveable tube section (not shown), such as one to which a light assembly is mounted.

[0064] The Swivelpole™ joint 1 10 has two connectors 120 and 120', similar to the first embodiment.

[0065] The connector 120 is shown in an exploded view in Figure 8. It includes three principal components: a fixed portion 122, a grasping member 124 and a force distributing member 126.

[0066] The fixed portion 122 in this embodiment forms part of the

Swivelpole™ joint 1 10, and is made from the same material (generally steel or other rigid metal). The fixed portion 122 is generally cylindrical in shape, with a hollow bore 128. The hollow bore 128 has an internal diameter slightly greater than the external diameter of the tube which is to be received therein.

[0067] The fixed portion 122 has an inner end at the Swivelpole™ joint 1 10, and an outer end 130 spaced from the Swivelpole™ joint 1 10.

[0068] The fixed portion 122 includes an annular shoulder 132 located near the outer end 130. The annular shoulder 132 has an inner diameter equal to the outer diameter of the cylindrical fixed portion 122, and an outer diameter about 1 .5 times the size of the inner diameter. The shoulder 132 has an axial thickness about one tenth its outer diameter.

[0069] The shoulder 132 has an annular upper surface 134 oriented towards the outer end 130. The upper surface 134 is tapered away from the inner diameter to the outer diameter, such that there is a generally

downward slope towards the outside. The upper surface 134 is thus frusto- conical in shape, with a cone angle greater than 150°. [0070] The shoulder 132 is spaced from the outer end 130 by about the same axial distance as the thickness of the shoulder 132.

[0071 ] A secondary shoulder portion 136 abuts the shoulder 132 on its inner axial side. The secondary shoulder portion 136 has a similar thickness to the shoulder 132, and an outer diameter about half that of the shoulder 132.

[0072] The grasping member 124 is formed from a pliable plastic material, such as a urethane. The grasping member 124 is generally hollow cylindrical in shape, with an internal wall 140 and an outer wall 142. The grasping member 124 extends in an axial direction from an inner or lower end 144 to an outer or upper end 146.

[0073] The internal wall 140 is generally cylindrical, and is sized to receive a tube portion (not shown) in a sliding fit.

[0074] The outer wall 142 has two portions: a generally cylindrical first portion 148 and a frusto-conical second portion 150. The two portions are separated at a step 152, located about three quarters of the way from the lower end 144 to the upper end 146.

[0075] The first portion 148 extends from the lower end 144 to the step 152. It has a diameter generally equal to the internal diameter of the bore 128, such that it can be received in the bore 128 in an easy sliding fit.

[0076] The second portion150 extends from the upper end 146 to the step 152, increasing in diameter from the upper end 146 to the step 152. It has a diameter at the upper end 146 about the same as that of the first portion 148, and a diameter at the step 152 about the same as the outer diameter of the fixed portion 122.

[0077] It will be thus appreciated that the grasping member 124 can be located such that its first portion 148 sits inside the bore 128, with the step 152 resting on the outer end 130 of the fixed portion 122, and its second portion 150 protruding above the outer end 130 of the fixed portion 122.

[0078] The grasping member 124 has a tube restraint at its lower end 144. In the embodiment shown, the tube restraint is an annular ring 154 which extends radially internally of the internal wall 140, and has an internal diameter smaller than the diameter of the tube section the grasping member 124 is arranged to receive.

[0079] The force distributing member 126 is generally frusto-conical in shape, with an internal wall 160, and an external wall 162. The internal wall 160 has two sections: a generally cylindrical section 164 arranged to locate, in use, about the outer end 130 of the fixed portion 122, and a frusto-conical section 166 arranged to locate, in use, about the second portion 150 of the grasping member 124. The frusto-conical section 166 has a similar cone angle to that of the second portion 150 of the grasping member 124.

[0080] The external wall 162 is generally frusto-conical in shape, and has a larger cone angle than the frusto-conical section of the internal wall 160. The thickness of the force distributing member 126 thus tapers from a narrow rim 167 at an upper end thereof to a relatively wide annulus 168 at a lower end thereof. The annulus 168 is of similar dimensions to the upper surface 134 of the shoulder 132, and is tapered in a complementary fashion to the upper surface 134 of the shoulder 132.

[0081 ] The force distributing member 126 includes three axially aligned channels 170 equally spaced about its periphery. The channels 170 are sized to receive bolts 172. In the embodiment shown, additional material is placed around the upper parts of channels 170 to ensure that an upper end of each channel 170 is defined by a flat ring 174, against which a head 176 of the corresponding bolt 172 can engage. [0082] The shoulder 132 includes three correspondingly located axially aligned bolt-receiving apertures 178. Each bolt-receiving aperture 178 is internally threaded, and is arranged to engage with threads of a bolt 172.

[0083] In use, the connector 120 is arranged as shown in Figure 9, such that the first portion 148 of the grasping member 124 is located in the bore 128 of the fixed portion 122; the force distributing member 126 is located about the second portion 150 of the grasping member 124 such that the annulus 168 is located over the shoulder 132; and the bolts 172 are passed through the channels 170 and loosely received in the bolt-receiving apertures 178.

[0084] A tube section can then be located in the connector 120, being received in the grasping member 124. The annular ring 154 will prevent the tube section from falling through the connector 120 and will maintain it loosely in position.

[0085] The bolts 172 can then be tightened into the bolt-receiving apertures 178. This has the effect of forcing the force distributing member 126 towards the fixed portion 122.

[0086] The frusto-conical section 166 of the internal wall 160 bears against the second portion 150 of the grasping member 124. This results in deformation of the grasping member 124, as it is squeezed against the tube section. This acts to hold the tube section in place by friction.

[0087] It will be appreciated that the more the bolts 172 are tightened, the more the grasping member 124 will deform and the greater will be the frictional force holding the tube section in position. Friction may be further increased by suitable finishing of the internal wall 140 of the grasping member 124, such as by the scoring of rings 182 in the internal wall.

[0088] In addition, it will be noted that the deformation of the grasping member 124 creates a water-proof seal within the connector 120. To this end, it will be appreciated that the bolt-receiving apertures 178 are located outside the circumference of the cylindrical part of the fixed portion, ensuring that any water entering the channels 170 cannot pass into the connector 120. The tapering of the upper surface 134 and complementary annulus 168 also act to drain water away from the connection.

[0089] The connector 120 includes a secondary fixing means. The secondary fixing means is provided by two secondary bolts 190 which are received in internally threaded secondary bolt-receiving apertures 194 radially oriented through the shoulder 132 and secondary shoulder portion 136. When the tube section has been fixed in position using the means described above, it can be further secured by the tightening of the

secondary bolts 190, such that their outer ends 192 bear against the tube section (through the first portion 148 of the grasping member 124).

[0090] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

Claims

1 . A connector for connecting a tube to another structure, the connector including a generally rigid fixed portion having a bore, a grasping member which is generally cylindrical in shape; a force distributing member and a collar;

wherein

2. A connector as claimed in claim 1 , wherein the force distributing member is a split ring member.

3. A connector for connecting a tube to another structure, the connector including a generally rigid fixed portion having a bore, a grasping member which is generally cylindrical in shape; and a force distributing member; the grasping member having an inner end and an outer end;

means for connecting the force distributing member to the fixed portion such that a generally axial load can be applied to the force distributing member;

wherein

4. A connector as claimed in any preceding claim, wherein the grasping member is a single contiguous member.

5. A connector as claimed in any preceding claim, wherein the axial force applied to the force distributing member is arranged to compress the grasping member, causing lateral expansion or bulging.

6. A connector as claimed in any preceding claim, wherein the fixed portion and the force distributing member are made out of a generally rigid first material, and the grasping member is made out of a relatively deformable second material.

7. A connector as claimed in claim 6, wherein the grasping member is formed from a material having a Poisson's ratio greater than 0.4.

8. A connector as claimed in any preceding claim, wherein the grasping member has a tube restraint at an inner end thereof.

9. A connector as claimed in claim 8, wherein the tube restraint is formed by an internal step at the inner end of the grasping member.

10. A connector as claimed in claim 8, wherein the tube restraint is formed by a closing of the grasping member at the inner end.

1 1 . A connector as claimed in any one of claims 1 to 7, wherein the fixed portion includes an internal shoulder arranged to receive an inner end of a tube.

12. A connector as claimed in any preceding claim, wherein the internal wall of the grasping member includes friction-increasing markings.

13. A connector as claimed in claim 3, or any one of claims 4 to 12 when dependent on claim 3, wherein the means for connecting the force distributing member to the fixed portion includes a collar.

14. A connector as claimed in claim 1 , claim 2, or claim 13, wherein the collar includes an internally threaded portion, the collar being arranged to locate about the force distributing member, the collar being arranged to engage with an external thread at an outer end of the fixed member, such that rotation of the collar about the threaded engagement translates into axial movement of the force distributing member.

15. A connector as claimed in claim 14, wherein the force distributing member has a generally frusto-conical outer surface, arranged to bear against a generally frusto-conical internal shoulder of the collar.

16. A connector as claimed in claim 15, wherein the frusto-conical outer surface is parallel to the frusto-conical inner surface of the force distributing member.

17. A connector as claimed in any preceding claim, wherein the fixed portion includes a shoulder at an outer end thereof, arranged to receive a base annulus of the force distributing member.

18. A connector as claimed in claim 17, wherein the force distributing member includes generally axial apertures spaced about its periphery, and arranged to align with generally axial apertures spaced about the periphery of the shoulder.

19. A connector as claimed in claim 18, wherein the means for connecting the force distributing member to the fixed portion includes bolts arranged to pass through aligned general axial apertures of the force distributing member and fixed portion.

20. A connector as claimed in claim 19, wherein the generally axial apertures of the fixed portion are internally threaded, so as to allow the bolts to be tightened therein and thus a generally axial force to be applied.

21 . A connector as claimed in claim 19, wherein the bolts include nuts located on an inner side of the shoulder, in use.

22. A connector as claimed in any one of claims 19 to 21 , wherein three bolts are spaced at 120° intervals about the force distributing member.

23. A connector as claimed in any one of claims 17 to 22, wherein the shoulder of the fixed portion and the base radius of the force distributing member are tapered with respect to the axial direction.

24. A connector as claimed in any preceding claim, wherein the connector includes a secondary fixing means.

25. A connector as claimed in claim 24, wherein the secondary fixing means operates in a radial direction.

26. A connector as claimed in claim 25, wherein the secondary fixing means includes at least one bolt receivable in a threaded aperture within the fixed portion, such that rotation of the bolt causes movement of the bolt in a radial direction into the bore of the fixed portion.

27. A connector as claimed in claim 26, where the at least one bolt of the secondary fixing means acts against the first portion of the grasping member.

28. A connector as claimed in claim 26 or 27, wherein the secondary fixing means includes two circumferentially spaced bolts.