WO2008102116A2

WO2008102116A2 - Annular clamp

Info

Publication number: WO2008102116A2
Application number: PCT/GB2008/000556
Authority: WO
Inventors: Guenther Hartig
Original assignee: Norma Uk Limited
Priority date: 2007-02-21
Filing date: 2008-02-19
Publication date: 2008-08-28
Also published as: WO2008102116A3; GB2446813A; GB0703355D0

Abstract

Annular clamp (110) comprising a split ring (116) having two ends (116a, 116b) and a clip (126). There is a respective lug (122, 124) on each of the ends of the split ring. Each lug extends outwardly from the split ring in a substantially radial direction. The split ring is moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively. The clip is arranged to engage the lugs so as to retain the split ring in a selected one of a plurality of predetermined positions between the open and closed configurations. There is also described such a clip as well as a method of connecting two pipes using the annular clamp.

Description

ANNUIAR CLAMP

FIELD OF THE INVENTION

The present invention relates to an annular clamp. In particular, the present invention relates to an annular clamp for connecting pipes.

BACKGROUND OF THE INVENTION

A variety of annular clamps are available to enable two pipes to be joined together. Such clamps are frequently used in the automotive industry. An example of a known annular clamp 10 is shown in figures Ia and Ib. The same clamp 10 is shown clamped around two pipes 12 and 14 arranged end to end in figures 2a and 2b. Clamp 10 comprises a split ring 16 having first and second ends 18 and 20 respectively.

There is a first lug 22 integrally formed on the first end 18. The first lug 22 extends outwardly from the split ring 16 in a substantially radial direction. The first lug 22 comprises a first aperture (not shown) formed therethrough in a substantially circumferential direction with respect to the split ring 16.

Similarly, there is a second lug 24 integrally formed on the second end 20 of the split ring 16. The second lug 24 extends outwardly from the split ring 16 in a substantially radial direction. Again, there is an aperture (not shown) formed through the second lug 20 in a substantially circumferential direction with respect to the split ring 16. The lug apertures communicate with each other when the lugs 22 and 24 are brought into a confronting relationship. The clamp 10 further comprises an assembly clip 26 integrally formed on the free end of the first lug 22. The clip 26 comprises a protruding member 27, a hook 28, and a straight portion 25 extending therebetween. The protruding member 27 extends outwardly from the first lug 22 in a substantially radial direction relative to the split ring 16. The straight portion 25 extends substantially perpendicularly from the protruding member 27 in a direction towards the second lug 24. The clip 26 is formed from a resilient material.

The free end of the second lug 24 comprises a protruding member 30 which extends outwardly from the second lug 24 in a substantially radial direction relative to the split ring 16. The clamp 10 also includes a nut 32 and an associated bolt 34. The nut 32 comprises a threaded aperture (not shown) to threadingly receive a threaded portion 36 of the bolt 34, as is known in the art. Furthermore, the nut 32 is fixed to the second lug 24. An 0-ring 35 is provided on the threaded portion 36 so as to retain the bolt 34 within the aperture of the first lug 22 when the bolt 34 is not engaged in the threaded aperture of the nut 32.

The split ring 16 has a U-shaped cross-section as shown in figure 3. This U-shaped cross-section enables the split ring 16 to be clamped around adjacent protruding rims 40 and 42 at the adjacent abutting ends of the pipes 12 and 14 respectively. Thus, when the pipes 12 and 14 are placed end to end, the protruding rims 40 and 42 together form a single protruding rim around the joint between the pipes 12 and 14. The lugs 22 and 24 also have U-shaped cross- sections . The split ring 16 includes a point of weakness 38 midway between the first and second ends 18 and 20. The point of weakness 38 comprises only a middle section of the U-shaped cross-section of the split ring 16. In other words, the side sections of the "U" are not present at the point of weakness 38.

The clamp 10 is shown in a closed configuration in figures Ia to 2b. In this configuration, the clamp has been tightened to its fullest extent by means of the nut 32 and bolt 34 such that the protruding member 27 abuts the protruding member 30.

In use, in order to join two pipes 12 and 14 together, it is first necessary to ensure that the bolt 34 is completely unscrewed from the nut 32 so that the bolt 34 is only retained in the aperture of the first lug 22 by the CD- ring 35.

An operator then manually opens the clamp 10 by pulling apart the first and second ends 18 and 20 of the split ring 16 such that the split ring 16 hinges about the point of weakness 38. This manual separation of the lugs 22 and 24 requires a fair amount of force and can be quite difficult. As the first and second ends 18 and 20 of the split ring 16 are pulled apart, the operator should additionally hold the resilient clip 26 out of the way such that hook 28 of the clip 26 does not engage with the protruding member 30 on the second lug 24 as the split ring 16 is opened.

The operator continues to open the clamp 10 until it is possible to longitudinally insert the pipe 12 with the protruding rim 40 into the split ring 16. The operator then also longitudinally inserts the pipe 14 with the protruding rim 42 into the other side of the split ring 16 of the clamp 10. Once the ends of the pipes 12 and 14 are thus inserted, the operator starts to manually close the clamp 10 by hinging the two sides of the split ring 16 about the point of weakness 38 until the hook 28 of the clip 26 passes over and then engages with the protruding member 30. In this loosely closed configuration, the operator may let go of the clamp 10 and it will be held loosely in place by clip 26.

At this stage, the operator re-engages the bolt 34 in the threaded aperture of the nut 32. The bolt 34 is then tightened by the operator so as to move the clamp 10 from the loosely closed configuration, in which the hook 28 of the clip 26 is engaged with the protruding member 30, to the fully closed configuration around the pipes 12 and 14 as shown in figures 2a and 2b. However, due to manufacturing tolerances of the pipes 12 and 14 and of the clamp 10, it is possible that the operator may not be able to. manually close the clamp 10 to the loosely closed configuration described above in which the hook 28 engages with the protruding member 30. This situation might occur if the pipes 12 and 14 were fairly large within the normal range of manufacturing tolerances and/or if the split ring 16 of the clamp 10 were fairly small within the normal range of manufacturing tolerances. Alternatively, the hook 28 of the clip 26 might engage with the protruding member 30 too early such that the pipes 12 and 14 are held too loosely for the clamp 10 to retain them within the split ring 16. This situation might occur if the split ring 16 of the clamp 10 were particularly large, and/or the pipes 12 and 14 were particularly small, within the normal range of manufacturing tolerances. — o ~~

The present invention seeks to provide an alternative clamp and assembly clip which solves these problems and offers various advantages over the prior art.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided an annular clamp comprising: a split ring having two ends; a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively; and a clip arranged to engage the lugs so as to retain the split ring in a selected one of a plurality of predetermined positions between the open and closed configurations.

Thus, a clamp according to the present invention has various tolerance settings which makes it easier to use and more versatile than the prior art clamping system. It is envisaged that engagement of the clip with the lugs may be direct or indirect.

Advantageously, the clip comprises a resilient member. Advantageously, the clip comprises a strip extending from one of the lugs towards the other lug, the strip having a plurality of projections arranged to engage said other lug so as to retain the split ring in each of the plurality of predetermined positions respectively. More advantageously, the strip comprises a section that is formed into a zigzag to define the plurality of projections. In a preferred embodiment, the split ring comprises two discrete circumferential sections joined together by a resilient connector which acts as a hinge between the two discrete circumferential sections so as to enable the split ring to move between the open and closed configurations. In this embodiment, the resilient connector makes it easier to manually close the clamp, thereby providing advantages in terms of ease of use over the prior art. More advantageously, the resilient connector is biased to hold the .split ring in the open configuration. Optionally, the resilient connector is attached to each of the two discrete circumferential sections of the split ring by welding. Optionally, the resilient connector is formed from spring steel.

In an alternative embodiment, the split ring is integrally formed and comprises at least one circumferential point of weakness which acts as a hinge to enable the split ring to move between the open and closed configurations.

Advantageously, the lugs are integrally formed with the split ring.

Advantageously, the clamp further comprises securing means for securing the split ring in the closed configuration. More advantageously, the securing means comprises a nut and a bolt for engaging the lugs.

In one advantageous embodiment, the clip is a discrete component. Thus, the clip may be formed from a different material to the split ring of the clamp so to obtain the required properties, such as elasticity. In contrast, the prior art clip is relatively stiff since it is integrally formed with the split ring which tends to be made of a relatively stiff material. In this case, the clip may be formed from plastics or metal or any other suitable material. Preferably, the clip is injection moulded for ease of manufacture. Alternatively, the clip may be formed from pressed metal, or from wire. Optionally, the clip is attached to one of the lugs. Optionally, the clip is attached to the nut.

In an alternative embodiment, the clip is integrally formed with one of the lugs . In a further alternative embodiment, the clip is integrally formed with the nut.

According to a second aspect of the present invention, there is provided a clip for use with an annular clamp, the annular clamp comprising a split ring having two ends and a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively, wherein the clip is arranged to engage the lugs so as to retain the split ring in a selected one of a plurality of predetermined positions between the open and closed configurations.

According to a third aspect of the present invention, there is provided a method of connecting two pipes using the clamp of the first aspect, the method comprising the steps of: ensuring the split ring is in the open configuration; aligning the pipes in a required connection position within the annular clamp; manually moving the split ring from the open configuration towards the closed configuration such that the clip engages the lugs and retains the split ring in the selected one of the plurality of predetermined positions between the open and closed configurations; and using the securing means to secure the split ring in the closed configuration.

Advantageously, the step of manually moving the split ring from the open configuration towards the closed configuration comprises : manually moving the split ring as far as manually possible towards the closed configuration so that the clip retains the split ring in the predetermined position that is as close to the closed configuration as possible. Thus, the selected predetermined position in this embodiment is the most closed predetermined position of the split ring that can be reached by manually closing the split ring.

According to a fourth aspect of the present invention, there is provided an annular clamp comprising: a split ring having two ends; a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively; and a clip arranged to engage the lugs so as to retain the split ring in a predetermined position between the open and closed configurations, wherein the clip is discretely formed in relation to both the split ring and the lugs.

Thus, in this embodiment, the clip is a discrete component, i.e. it is discrete both from the split ring and from each of the lugs. This provides various advantages as described in the detailed description section below. Advantageously, the clip is formed from a material having a greater resilience than the material of both the split ring and the lugs .

Advantageously, the clip is injection moulded. Alternatively, the clip may be formed from pressed metal, or from wire.

Advantageously, the clip is detachable from and re- attachable to the clamp. In one embodiment, the clip comprises an engagement portion for engaging one of the lugs. Optionally, the engagement portion comprises an aperture arranged to align with an aperture of said one lug in use. Optionally, the engagement portion further comprises at least one attachment flange extending substantially parallel to the axis of the aperture, the at least one attachment flange being arranged to pass through the aperture in said one lug and to thereby engage with said one lug so as to attach the clip to said one lug.

In one embodiment, the clip further comprises: a substantially straight portion arranged to extend from said engagement portion towards the other lug; and a hook connected to the straight portion that is arranged to engage said other lug so as to retain the split ring in said predetermined position.

In one embodiment, the clamp further comprises securing means for securing the split ring in the closed configuration. Advantageously, the securing means comprises a nut and a bolt for engaging the lugs. Optionally, the clip is attachable to the nut .

In one embodiment, the clip is attachable to one of the lugs .

According to a fifth aspect of the present invention, there is provided a method of manufacturing an annular clamp, the method comprising the steps of: providing a split ring having two ends and a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively; providing a clip that is discretely formed in relation to both the split ring and the lugs; and attaching the clip to the clamp such that the clip is arranged to engage the lugs so as to retain the split ring in a predetermined position between the open and closed configurations.

Other preferred features of the present invention are set out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which:

Figure Ia shows a prior art clamp and assembly clip arrangement; Figure Ib is a perspective view of the arrangement of figure Ia;

Figure 2a shows two pipes clamped together by the clamp of figures Ia and Ib;

Figure 2b is a perspective view of the arrangement of figure 2a;

Figure 3 is a partial cross-sectional view of the arrangement of figures 2a and 2b;

Figure 4 shows a clamp and assembly clip arrangement according to an embodiment of the present invention, the clamp being shown in an open configuration;

Figure 5a shows an assembly clip according to an embodiment of the present invention;

Figure 5b is a perspective view of the assembly clip of figure 5a; Figure 6a is a partial view of the clamp of figure 4 with the assembly clip engaged in a first predetermined position; Figure 6b is a partial view of the clamp of figure 4 with the assembly clip engaged in a second predetermined position; and

Figure 6c is a partial view of the clamp of figure 4 with the assembly clip engaged in a third predetermined position;

Figure 7 shows the clamp of figure 4 in a closed configuration; and

Figure 8 is a perspective view of an assembly clip according to another embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Figure 4 shows a clamp 110 according to one embodiment of the present invention. As for the prior art clamp 10, the clamp 110 comprises a split ring 116 having first and second ends 118 and 120 respectively and a U-shaped cross-section. There are first and second lugs 122 and 124 integrally formed on the respective first and second ends 118 and 120 of the split ring 116. The lugs 122 and 124 also have U-shaped cross- sections. Furthermore, as in the prior art, the clamp 110 also includes a nut 132 fixed to the lug 122 and a bolt 134 having a threaded portion 136.

A free end 123 of the first lug 122 comprises an integrally formed protruding member 130a which extends outwardly from the first lug 122 in a substantially radial direction relative to the split ring 116. Similarly, the second lug 124 comprises an integrally formed protruding member 130b which extends outwardly from the second lug 124 in a substantially radial direction relative to the split ring 116. The split ring 116 is formed from two discrete circumferential sections 116a and 116b joined together by a resilient connector 138. The first circumferential section 116a extends from the first end 118 of the split ring 116 to a connection end 119 which is joined to the connector 138. Similarly, the second circumferential section 116b extends from the second end 120 of the split ring 116 to a connection end 121 which is joined to the connector 138. The resilient connector 138 is biased to hold the split ring 116 in the open configuration of the clamp 110 which is shown in figure 4.

The connector 138 may be formed from a strip of material such as spring steel, and may be joined to the connection ends 119 and 121 of the circumferential sections 116a and 116b by welding. One end of the strip of the connector 138 is affixed to an external surface of the U- shaped cross-section of the connection end 119. The other end of the strip is affixed to an external surface of the U- shaped cross-section of the connection end 121. In this connected state, there is a small gap 131 between the two connection ends 119 and 121 of the circumferential sections 116a and 116b of the split ring 116. Flanges 139 extend outwardly from the elongate sides of the strip of the connector 138. These flanges 139 are bent relative to the strip to enable them to be attached to the external sides of the U-shaped cross-section of the connection ends 119 and 121. Thus, once affixed to the connection ends 119 and 121, parts of the connector 138 have U-shaped cross-sections which sit around the U-shaped cross-sections of the connection ends 119 and 121.

The clamp 110 further comprises an assembly clip 126 attached to the first lug 122. The assembly clip 126 is shown in more detail in figures 5a and 5b. As can be seen, the clip 126 is formed from an elongate strip of material, such as spring steel, which has been bent into the shape shown in figures 5a and 5b. The clip 126 may be integrally formed from plastics or from a metal, such as steel. The clip comprises an attachment portion 152, a straight portion 150 and zigzag portion 153.

The attachment portion 152 is located at one end of the elongate clip 126 and is arranged to be attached to the free end 123 of the first lug 122. In particular, the attachment portion is shaped so as to closely track an external surface of the free end 123. Furthermore, the attachment portion 152 comprises attachment members 154 as well as a semi-circular cut away portion 156 to fit around the fixed nut 132. In one embodiment, the attachment portion 152 of the clip 126 is attached to the first lug 122 by welding.

The straight portion 150 extends between the attachment portion 152 and the zigzag portion 153. When the clip 126 is correctly attached to the clamp 110, the straight portion 150 extends away from the free end 123 in a substantially circumferential direction with respect to the split ring 116 and extends towards the second lug 124.

The zigzag portion 153 comprises three zigzags. When affixed to the clamp 110, a first zigzag section 128a extends substantially perpendicularly from the straight section 150 towards the centre of the split ring 116. The strip of material forming the clip 126 is then bent the other way to form a second section 129a of the first zigzag. At the end of section 129a, the strip is bent back the other way again so as to form a first section 128b of the second zigzag. This zigzag formation continues until there are three first zigzag sections 128 and three second zigzag sections 129. The three first zigzag sections 128 are substantially parallel to one another. Similarly, the three second zigzag sections 129 are substantially parallel to one another.

There is a bend 127a between the first section 128a and the second section 129a of the first zigzag. There are similar bends 127b and 127c between the first and second sections of the second and third zigzags respectively. The bends 127 are arranged in a substantially straight line as shown by dashed line AA' in figure 5a.

There is a bend 125a between the second section 129a of the first zigzag and the first section 128b of the second zigzag. There is a similar bend between the second section 129b of the second zigzag and first section 128c of the third zigzag. The second section 129c of the third zigzag has a free end 125c. The free end 125c, the bends 125b and 125a, and the straight section 150 of the clip 126 are arranged in a substantially straight line as shown by dashed line BB¹ in figure 5a.

In use, the resilient connector 138 is biased towards the open configuration of figure 4, and the clamp 110 is usually delivered in this configuration. Thus, this embodiment provides the advantage over the prior art that there is no need for the operator to initially unscrew the bolt 134 from the nut 132. Therefore, in use, the operator simply longitudinally inserts the first pipe 12 with the protruding rim 40 into the U-shaped cross-section of the split ring 116, and then longitudinally inserts the second pipe 14 with the protruding rim 42 into the other side of the split ring 116 of the clamp 110. Once the ends of the pipes 12 and 14 are thus inserted, the operator starts to manually close the clamp 110 by hinging the two sections 116a and 116b of the split ring 116 about the resilient connector 138. As the clamp 110 is closed, the section 129c of the third zigzag of the clip 126 will abut against part of the protruding member 130b of the second lug 124. As the operator continues to close the clamp 110, the protruding member 130b will pass over the bend 127c of the clip 126 such that the protruding member 130b is then situated between sections 128c and 129b of the zigzag portion 153 as shown in figure 6a. Since the resilient connector 138 is biased towards the open configuration of the clamp 110, if the operator lets go of the clamp at this time, a surface of the protruding member 130b will abut against a surface of the section 128c, thus holding the clamp in the loosely closed configuration shown in figure 6a.

Depending on manufacturing tolerances, the clamp 10 may not be sufficiently closed in the loosely closed configuration of figure 6a so as to enable the operator to safely let go of the pipes 12 and 14 since one or both of the pipes 12 and 14 may be attached to heavy components such as an engine and may therefore simply force their way out of the held configuration of figure 6a. Therefore, if possible, the operator manually closes the clamp 110 further to the second loosely closed configuration as shown in figure 6b. In this configuration, the protruding member 130b is located between sections 128b and 129a. Furthermore, due to the bias of the resilient connector 138, a surface of the protruding member 130b abuts against a surface of the section 128b. Again, depending on manufacturing tolerances, the operator may continue to close the clamp 110 manually to the third loosely closed configuration shown in figure 6c. This configuration is particularly useful for pipes which are fairly small within the normal range of manufacturing tolerances or a clamp 110 having a fairly large split ring 116 within the normal range of manufacturing tolerances.

Having manually closed the clamp 110 as far as possible, the operator engages the bolt 134 in the threaded aperture of the nut 132. The bolt 134 is then tightened by the operator so as to move the clamp 110 from the chosen loosely closed configuration to the fully closed configuration which is shown in figure 7. One of the pipes 14 is also shown in the closed configuration of figure 7. An alternative embodiment of an assembly clip 226 is shown in figure 8. The clip 226 is similar to the clip 126 except for differences in the attachment portion 252. In particular, the attachment portion 252 comprises an elongate aperture 258. The aperture has elongate opposite straight sides 260 and arcuate sides 262 therebetween. The aperture 258 is arranged to substantially coincide with the aperture of the first lug 122. The attachment portion 252 further comprises attachment flanges 254 as shown in figure 8. The attachment flanges 254 extend from the sides 260 of the aperture 258 in a substantially perpendicular direction relative to the attachment portion 252. In other words, the attachments flanges 254 extend substantially parallel to the axis of the aperture 258. In use, the aperture 258 of the attachment member is aligned with the aperture in the first lug 122 such that the bolt 134 is able to pass linearly through both apertures. The attachment flanges 254 extend through the first lug aperture and are resiliently biased to engage with the first lug 122 at the edges of the first lug aperture so as to connect the clip 226 to the first lug 122. In use, there is sufficient room for both the bolt 134 and the attachment flanges 254 to pass through the first lug aperture.

In a further alternative embodiment (not shown) , an assembly clip similar to the prior art assembly clip 26 of Figure 1 is provided as a separate discrete component, rather than being integrally formed on the free end of the first lug 22 as in the prior art. The discrete assembly clip would then be attachable to the nut or one of the lugs of the clamp. This attachment could be accomplished in a similar way to that described above with reference to the attachment portions 152 or 252 of clips 126 and 226 respectively.

In this embodiment, there are not multiple predetermined positions in which the clip may retain the split ring. Instead, there is only one predetermined position in which the clip is arranged to engage the lugs so as to retain the split ring between the open and closed configurations. However, even in the absence of multiple predetermined positions, the discrete nature of the clip provides a number of advantages. For example, the clip may be formed from a different material to that of the split ring of the clamp. This means that the required properties of the clip, such as resilience/elasticity, may be more effectively realised. In contrast, the prior art clip is inevitably relatively stiff since it is integrally formed with the relatively stiff split ring. In addition, the clip of this embodiment could be formed from plastics or metal or any other suitable material. Preferably, the clip is injection moulded for ease of manufacture. Also, the clip of this embodiment may be detachable from and re-attachable to the clamp, which means that the clip may be detached from the clamp once the clamp has been used to connect two pipes together as described above. This may be useful if there is little space available around the clamp once the joined pipes are in place.

Although preferred embodiments of the invention have been described, it is to be understood that these are by way of example only and that various modifications may be contemplated within the scope of the appended claims.

Claims

CLAIMS :

1. An annular clamp comprising: a split ring having two ends; a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively; and a clip arranged to engage the lugs so as to retain the split ring in a selected one of a plurality of predetermined positions between the open and closed configurations.

2. The annular clamp of claim 1 wherein the clip comprises a resilient member.

3. The annular clamp of claim 1 or claim 2 wherein the clip comprises a strip extending from one of the lugs towards the other lug, the strip having a plurality of projections arranged to engage said other lug so as to retain the split ring in each of the plurality of predetermined positions respectively.

4. The annular clamp of claim 3 wherein the strip comprises a section that is formed into a zigzag to define the plurality of projections.

5. The annular clamp of any of claims 1 to 4 wherein the split ring comprises two discrete circumferential sections joined together by a resilient connector which acts as a hinge between the two discrete circumferential sections so as to enable the split ring to move between the open and closed configurations.

6. The annular clamp of claim 5 wherein the resilient connector is biased to hold the split ring in the open configuration .

7. The annular clamp of claim 5 or claim 6 wherein the resilient connector is attached to each of the two discrete circumferential sections of the split ring by welding.

8. The annular clamp of any of claims 5 to 7 wherein the resilient connector is formed from spring steel.

9. The annular clamp of any of claims 1 to 4 wherein the split ring is integrally formed and comprises at least one circumferential point of weakness which acts as a hinge to enable the split ring to move between the open and closed configurations .

10. The annular clamp of any preceding claim wherein the lugs are integrally formed with the split ring.

11. The annular clamp of any preceding claim further comprising securing means for securing the split ring in the closed configuration.

12. The annular clamp of claim 11 wherein the securing means comprises a nut and a bolt for engaging the lugs.

13. The annular clamp of any of claims 1 to 12 wherein the clip is a discrete component.

14. The annular clamp of claim 13 wherein the clip is attached to one of the lugs .

15. The annular clamp of claim 13 when dependent on claim 12 wherein the clip is attached to the nut.

16. The annular clamp of any of claims 1 to 12 wherein the clip is integrally formed with one of the lugs.

17. The annular clamp of claim 12 wherein the clip is integrally formed with the nut.

18. A clip for use with an annular clamp, the annular clamp comprising a split ring having two ends and a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively, wherein the clip is arranged to engage the lugs so as to retain the split ring in a selected one of a plurality of predetermined positions between the open and closed configurations.

19. The clip of claim 18 wherein the clip comprises a resilient member.

20. The clip of claim 18 or claim 19 wherein the clip comprises a strip arranged to extend from one of the lugs towards the other lug, the strip having a plurality of projections arranged to engage said other lug so as to retain the split ring in each of the plurality of predetermined positions respectively.

21. The clip of claim 20 wherein the strip is formed into a zigzag to define the plurality of projections.

22. The clip of any of claims 18 to 21 wherein the clip comprises an integrally formed nut for receiving a bolt.

23. A method of connecting two pipes using the annular clamp of claim 11 or claim 12, the method comprising the steps of: ensuring the split ring is in the open configuration; aligning the pipes in a required connection position within the annular clamp; manually moving the split ring from the open configuration towards the closed configuration such that the clip engages the lugs and retains the split ring in the selected one of the plurality of predetermined positions; and using the securing means to secure the split ring in the closed configuration.

24. The method of claim 23 wherein the step of manually moving the split ring from the open configuration towards the closed configuration comprises: manually moving the split ring as far as manually possible towards the closed configuration so that the clip retains the split ring in the predetermined position that is as close to the closed configuration as possible.

25. An annular clamp comprising: a split ring having two ends; a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively; and a clip arranged to engage the lugs so as to retain the split ring in a predetermined position between the open and closed configurations, wherein the clip is discretely formed in relation to both the split ring and the lugs .

26. The annular clamp of claim 25 wherein the clip is formed from a material having a greater resilience than the material of both the split ring and the lugs.

27. The annular clamp of claim 25 or claim 26 wherein the clip is formed by injection moulding or formed from pressed metal or formed from wire.

28. The annular clamp of any of claims 25 to 27 wherein the clip is detachable from and re-attachable to the clamp.

29. The annular clamp of any of claims 25 to 28 wherein the clip comprises an engagement portion for engaging one of the lugs .

30. The annular clamp of claim 29 wherein the engagement portion comprises an aperture arranged to align with an aperture of said one lug in use.

31. The annular clamp of claim 30 wherein the engagement portion further comprises at least one attachment flange extending substantially parallel to the axis of the aperture, the at least one attachment flange being arranged to pass through the aperture in said one lug and to thereby engage with said one lug so as to attach the clip to said one lug.

32. The annular clamp of any of claims 29 to 31 wherein the clip further comprises: a substantially straight portion arranged to extend from said engagement portion towards the other lug; and a hook connected to the straight portion that is arranged to engage said other lug so as to retain the split ring in said predetermined position.

33. The annular clamp of any of claims 25 to 32 further comprising securing means for securing the split ring in the closed configuration.

34. The annular clamp of claim 33 wherein the securing means comprises a nut and a bolt for engaging the lugs.

35. The annular clamp of claim 34 wherein the clip is attachable to the nut.

36. The annular clamp of any of claims 25 to 34 wherein the clip is attachable to one of the lugs.

37. A method of manufacturing an annular clamp, the method comprising the steps of: providing a split ring having two ends and a respective lug on each of the ends of the split ring, each lug extending outwardly from the split ring in a substantially radial direction, the split ring being moveable between an open configuration and a closed configuration in which the lugs are mutually spaced to a greater or lesser extent respectively; providing a clip that is discretely formed in relation to both the split ring and the lugs; and attaching the clip to the clamp such that the clip is arranged to engage the lugs so as to retain the split ring in a predetermined position between the open and closed configurations .