阅读说明：本技术 用于连接管道、包括套环和垫圈的夹紧系统 (Clamping system for connecting pipes, comprising a collar and a gasket ) 是由 埃里克·梅斯纳德 于 2021-04-06 设计创作，主要内容包括：夹紧系统用于连接两个管道,两个管道的相对端部具有突出的承载表面。夹紧系统包括可被夹紧的套环(10)及垫圈(20)。套环包括皮带(12),皮带的内周面限定支承表面可插入其中的凹部。垫圈(20)包括环形部分(22),其布置在皮带内并承载支撑凸耳(30),支撑凸耳具有被配置成钩在皮带的边缘(13)上的钩子(30A)和在环形部分(22)与钩子(30A)之间延伸的链接部分(30B)。链接部分承载至少一个保持翼(30D),保持翼径向向外弯曲并具有保持边缘(30D’),保持翼(30D)具有朝向其自由端部(30D”)减小的轴向测量的宽度(130D),皮带的边缘(13)被容纳在形成于保持边缘与钩子之间的空间中。(The clamping system is used to connect two pipes, the opposite ends of which have protruding bearing surfaces. The clamping system comprises a collar (10) and a washer (20) which can be clamped. The collar includes a belt (12) having an inner peripheral surface defining a recess into which the bearing surface is insertable. The gasket (20) comprises a loop portion (22) arranged within the belt and carrying a support lug (30) having a hook (30A) configured to hook onto an edge (13) of the belt and a link portion (30B) extending between the loop portion (22) and the hook (30A). The link portion carries at least one retaining wing (30D) bent radially outwards and having a retaining edge (30D'), the retaining wing (30D) having an axially measured width (130D) decreasing towards its free end (30D "), the edge (13) of the belt being accommodated in a space formed between the retaining edge and the hook.)

1. A clamping system for connecting first and second pipes (1, 2), the opposite ends of the first and second pipes (1, 2) having bearing surfaces (1' A, 2' A) projecting with respect to the cylindrical outer surfaces of the pipes, the system comprising a collar (10) capable of being clamped comprising a strap (12) which can be engaged with the bearing surfaces by its inner peripheral surface defining a recess (15), and a gasket (20) which can be inserted in the recess (15), the gasket (20) comprising an annular portion (22) disposed inside the strap and carrying a supporting lug (30) having a hook (30A) configured to hook onto the strap's ground edge (13), and a linking portion (30B) extending between the annular portion (22) and the hook (30A), the link portion carries at least one retaining wing (30D) bent radially outwards and having a retaining edge (30D') spaced apart from the hook, the retaining wing (30D) having a width (130D) measured axially, which decreases towards its free end (30D "), the edge (13) of the strap being accommodated in the space formed between the retaining edge and the hook.

2. Clamping system according to claim 1, wherein the retaining wing (30D) has a triangular shape.

3. Clamping system according to claim 1, wherein the width of the retaining wing (30D) at its free end (30D ") is less than or equal to 1/4 of the width of the retaining wing (30D) at its base (30D"').

4. Clamping system according to claim 1, wherein the width of the retaining wing (30D) at its free end (30D ") is less than or equal to 1/5 of the length (130B) of the link portion (30B).

5. Clamping system according to claim 1, wherein the width of the retaining wing (30D) at its base (30D "') is less than or equal to 1/3 of the length (130B) of the link portion (30B).

6. Clamping system according to claim 1, wherein the free end (30D ") of the retaining wing forms a tip.

7. Clamping system according to claim 1, wherein the retaining edge (30D') of the retaining wing (30D) has a concave shape when viewed radially.

8. Clamping system according to claim 1, wherein an edge (30D1) of the retaining wing (30D) opposite the retaining edge (30D') has a convex shape when viewed radially.

9. Clamping system according to claim 1, wherein the linking part (30B) has a retaining wing (30D) on each of its two edges (30B').

10. The clamping system of claim 1, wherein the support ledge has an inward projection (30C) configured to grip a bearing surface of a pipe inserted into the collar.

11. Clamping system according to claim 10, wherein said inward projection (30C) comprises a tongue carried by said link portion (30B) and bent radially inwards with respect to said link portion.

12. Clamping system according to claim 1, wherein the link portion (30B) extends substantially axially.

13. Clamping system according to claim 1, wherein the support lug (30) is integrally formed with the annular portion (22).

14. The clamping system of claim 1, wherein at least one of the support lugs (230) has a centering wing (232D) that is curved radially inward and has a longitudinal edge (232' D).

Technical Field

The present invention relates to a clamping system for connecting a first pipe and a second pipe, the opposite ends of the first pipe and the second pipe having bearing surfaces projecting relative to the cylindrical outer surface of the pipes, the system comprising a collar capable of clamping around the bearing surfaces of the pipes and a gasket.

Background

Patents EP 1451498, EP 2598785 and EP 3232107 disclose a clamping system comprising a collar with a belt that can be clamped by reducing its diameter and a washer pre-mounted in the collar. More specifically, the system includes a gasket including a closed annular portion forming a seal and a lug connecting the seal to a collar. The gasket is first secured relative to the belt of the collar such that an annular space is formed between the annular portion of the gasket and the inner periphery of the belt to allow engagement of the end of the conduit between the annular portion of the gasket and the belt. The inner conduit itself is then engaged to contact the annular portion of the gasket. The device is particularly suitable for clamping two pipes fitted together and having radially projecting surfaces which act as bearings for a clamping collar comprising a recess capable of receiving these radially projecting surfaces, the annular portion of the gasket itself having a shape adapted to these projecting surfaces.

In particular, the gasket can be made of a metal of the stainless steel type, but also of a belt of the collar.

In the above patents, in particular in EP 1451498 and EP 2598785, the washer is held in place relative to the collar in the loose state by means of lugs of different types. Some of the lugs are internal lugs that are fully received within the interior of the belt and have the form of radially projecting tabs to bear against the inner periphery of one of the sides of the belt and retain the gasket for axial displacement relative to the collar in a first direction outwardly of that side. The other lugs, which are longer than the inner lugs, are shaped like hooks, the heads of which project outwards beyond the edge of the side of the belt in order to hook thereon, thus retaining the gasket with respect to axial displacement in the opposite direction. Thus, both types of lugs maintain the axial positioning of the washer relative to the collar before clamping the collar and ensure the presence of the annular space described above. There are also other lugs for centering the washer relative to the collar.

These systems are satisfactory but require relatively complex geometries and different manufacturing steps to equip the gasket of the lugs with these different types of lugs.

Disclosure of Invention

The present disclosure is directed to at least substantially overcoming the above-mentioned disadvantages.

The present invention therefore relates to a clamping system for connecting a first pipe and a second pipe, the opposite ends of the first pipe and the second pipe having bearing surfaces projecting with respect to the cylindrical outer surface of the pipes, the system includes a collar capable of being clamped, the collar including a belt capable of engaging a support surface through an inner periphery thereof defining a recess, the bearing surface being insertable into the recess, the gasket comprising an annular portion disposed inside the belt, and a load-bearing lug, the lug having a hook configured to hook onto an edge of the strap and a link portion extending between the loop portion and the hook, the link portion carrying at least one retaining wing, the retaining wing being bent radially outwardly and having a retaining edge spaced from the hook, the retaining wing has an axially measured width that decreases toward its free end, the edge of the strap being received in the space formed between the retaining edge and the hook.

The same support lug, by means of its hooks and curved retaining wings, therefore allows to retain the gasket in two opposite axial directions with respect to the collar and to maintain the annular space required to engage the end of the pipe between the gasket and the adjacent side of the belt, in order to pre-mount the clamping system on this pipe. It thus performs the biaxial retention function and the spacer function of the gasket. According to the invention, the axial width of the retaining wing decreases towards its free end. During clamping of the collar, the support lugs, in particular the retaining wings, are deformed to effect clamping of the belt against the bearing surface. It is indeed important to minimise the radial space requirement of the support lugs, in particular the retaining wings, in the state in which the collar is clamped on the pipe. This deformation of the retaining wing, for example by bending the retaining wing radially inwards, reduces its radial height, with the same effect as the spreading out of the retaining wing relative to the link portion carrying the retaining wing. A portion of the force applied to clamp the collar is consumed to cause deformation of the retaining wings and is therefore not directly useful for the clamping force of the belt on the support surface. The applicant has realised that providing a small width at the free end of the retaining wing makes the retaining wing more sensitive to radial deformation forces. In other words, due to its particular shape, the retaining wing starts to deform under moderate force and once this deformation starts, it continues with the clamping deformation of the collar without consuming a significant clamping force. Thus, although the retaining wing has a sufficient width at its base to enable it to withstand axial deformation and perform the biaxial retaining function and the spacer function of the gasket, during clamping of the collar, the retaining wing deforms without consuming a significant portion of the force applied for clamping. The width of the retaining wing may not decrease continuously from its base, but at least in the region of its radially outer free end, the retaining wing has a width that decreases as it progresses radially outwards up to this free end. However, it is advantageous for the width of the retaining wing to decrease from its base to its free end.

Optionally, the retaining wing has a triangular shape.

Optionally, the width of the retaining wing at its free end is less than or equal to 1/4, optionally less than or equal to 1/10, of the width of the retaining wing at its base.

Optionally, the width of the retaining wing at its free end is less than or equal to 1/5, optionally less than or equal to 1/15, of the length of the link portion.

Optionally, the width of the retention wing at its base is less than or equal to 1/3 of the length of the link portion.

Optionally, the free end of the retaining wing forms a tip.

Optionally, the retaining edge of the retaining wing has a concave shape when viewed radially.

Optionally, an edge of the retaining wing opposite the retaining edge has a convex shape when viewed radially.

Optionally, the linking part has a retaining wing on each of its two edges.

Optionally, the support ledge has an inward projection configured to grip a bearing surface of a pipe inserted into the collar.

Optionally, the inward projection comprises a tab carried by the link portion and bent radially inward relative to the portion.

Optionally, the tab is cut out of the linking portion.

Optionally, the tab points away from the hook.

Optionally, the linking portion extends substantially axially.

Optionally, the support ledge is integrally formed with the annular portion.

Drawings

Fig. 1 is a perspective view of a clamping system according to the present disclosure taken from a first side.

Fig. 2 is a perspective view of the system shown in fig. 1 taken from another side.

Fig. 3 is an exploded perspective view showing the different elements constituting the clamping system, respectively, and the ends of two pipes assembled using the system.

Fig. 4 is an axial sectional view in plane IV of fig. 1, showing on the one hand the clamping system according to the present disclosure and on the other hand the ends of two pipes to be assembled using this clamping system.

Fig. 5 is an enlarged view of detail V of fig. 1.

Fig. 6 is an enlarged view of detail VI of fig. 2.

Fig. 7 is a view of detail VII of fig. 4.

Fig. 8 is a partial axial cross-sectional view of a variation similar to fig. 4.

Fig. 9 is a partial perspective view showing a modification of the seal member.

Fig. 10 shows a variant of the support lug.

Detailed Description

Fig. 1 shows a clamping collar 10 comprising a belt 12 having ends radially raised to form clamping lugs 12A and 12B, respectively. To clamp the collar, the diameter of the belt is reduced by the cooperation of the clamp screw 14 with the clamp lugs 12A and 12B. The shank 14B of the screw passes through the hole of the clamping lug, the head 14A of which cooperates with the lug 12A, and the opposite end is provided with a nut 14C, which nut 14C cooperates in this case with the lug 12B via a spacer 14D.

The belt 12 has an inner recess 15 (better seen in FIG. 4) formed between the two sides of the belt (12C and 12D, respectively). In this case a gasket 20 forming a seal is provided inside the belt. As best shown in fig. 4, the clamping system is used to connect two pipes 1 and 2, the ends of the pipes 1 and 2 being provided with bearing surfaces 1A and 2A. To connect the pipes, their ends are brought together until they are axially located in the recesses 15 and the diameter of the belt is reduced so that the sides 12C and 12D clamp onto the bearing surfaces 1A and 2A. In this case, bearing surfaces 1A and 2A are formed on the radial flanges of the ends of the pipes 1, 2.

Hereinafter, the gasket 20 will be referred to as a sealing member, although this sealing function is only one example of a function for the gasket. It may be used primarily to pre-mount the collar on one of the pipes. As shown, the seal 20 is disposed within the collar. To connect the pipes 1 and 2, the front surfaces 1'a and 2' a of the ends of the pipes 1A and 2A are placed on either side of the annular sealing portion 21 present in the seal 20.

Within the meaning of the present disclosure, the forward direction of a pipe 1 or 2 is the direction towards the other pipe 2 or 1 when their ends are brought together to assemble the pipe. Thus, the bearing surfaces 1A and 2A are formed on the back of the radial flange at the end of the pipe. The backward direction is obviously the opposite direction. For one element, the inward direction is the direction toward axis a. The outward direction is the opposite direction.

In this case, the annular sealing portion includes a metal gasket 22 and a non-metal based gasket 24 secured to the metal gasket. In this case, it will be understood by considering fig. 1, 2 and 3 in combination, that the annular sealing portion includes a metal gasket 22, a non-metal based gasket 24 disposed on a first face of the metal gasket and another non-metal based gasket 26 disposed on the other face of the metal gasket. Thus, the metal gasket is sandwiched between the non-metal based gaskets 22 and 24.

For example, the metal washer 22 may be made of the same metal as the belt 12, such as stainless steel. The non-metal based gaskets 24, 26 may be formed from a composite material, such as a mica based material.

Non-metal based gaskets 24 and 26 are carried by the metal gasket 22. As shown in fig. 1 to 3, the metal washer 22 is provided with support lugs by which the metal washer and the non-metal based washer are supported relative to the collar 10. Thus, the seal is pre-installed in the belt, that is, the seal is carried by the collar before it is placed over the pipe and clamped, so that the collar and seal can be handled as a unit.

Furthermore, the metal gasket may also carry support lugs for pre-mounting the gasket-equipped collar on one of the pipes to be assembled. Thus, the assembly formed by the collar and the seal may be placed at the end of one of the pipes and held in place at that end before the end of the other pipe is placed and the collar is clamped. These same lugs may have a dual function: the seal is pre-installed in the belt and the assembly formed by the collar and the seal is pre-installed at the end of one of the pipes. These supporting lugs are carried by the outer periphery of the metal washer 22 (away from the axis a of the belt).

In this case, three different types of lugs are shown. As best seen in fig. 7 and 9, support lug 30 has an end 30A that is bent into a hook so as to be able to hook onto edge 13 of side 12C of belt 12. Between the connection region of the lug 30 with the outer periphery 22' of the metal washer 22 and the hook 30A, the lug 30 has a link portion 30B which in this case extends substantially axially, that is to say substantially parallel to the axis a. As better seen in fig. 7, the link portion 30B has a hook tab 30C cut in the link portion 30B and bent radially inward while extending toward its free end in a direction from the hook 30A to the outer periphery 22' of the metal gasket. The tongue 30C serves to clamp the gasket against the bearing surface 1A of the pipe 1 to hold the pre-installed collar on the end of the pipe. It can be seen that the orientation of the tab 30C in a direction away from the hook 30A prevents the duct from releasing from the gasket in a rearward direction of the duct 1, along arrow R1 indicated in FIG. 4. The tongue 30C of the lug 30 is one example of an internal protrusion configured to grip/clamp the bearing surface 1A inserted into the collar.

Furthermore, the support lug 30 has a retaining wing 30D, the retaining wing 30D being bent radially outwards from the longitudinal edge of the link portion 30B, i.e. moving away from the axis a. Furthermore, the retaining wing 30D has a retaining edge 30D ', which, when the seal is pre-mounted in the gasket, 30D' is directed towards the inner surface of the hook 30A and therefore of the side 12C of the belt 12. These retaining edges 30D' are spaced from the inner surface of the hook 30A. The edge 13 of the side 12C is received in the space thus formed between the hook 30A and the retaining edge 30D. This allows the metal washer 22 to be retained relative to the belt of the collar by retaining it in both axial directions.

Although the figures show the linking portion 30B as having a retaining wing 30D (substantially parallel to the axis a ') on each of its two longitudinal edges 30B', it may have only one retaining wing.

As can be seen in fig. 7, the retaining wing 30D has a width 130D measured axially which decreases towards its free end 30D ". Thus, during clamping of the collar, the retaining wings 30D may naturally slide against the inner periphery of the side 12C and bend or break without impeding the clamping.

It can be seen that the width of the retaining wings at their free ends is very small, so as to be almost in point contact with the inner peripheral point of the side faces 12C in the unclamped state of the collar. The width of the retaining wing at its free end is less than or equal to 1/4 of the width of the retaining wing at its base 30D' ", which base is the part of the retaining wing by which the retaining wing is attached to the link part 30B carrying the retaining wing. The width of the retaining wing at its free end 30D "is even less than or equal to 1/10 of its width at its base 30D".

The width of the retaining wing 30D at its free end 30D "is less than or equal to 1/5 of the length 130B of the link portion 30B, the length 130B being measured axially. The width of the retaining wing 30D at its free end 30D "is even less than or equal to 1/15 of the length 130B of the link portion 30B.

The width of the retaining wing 30D at its base 30D' "is less than or equal to 1/3 of the length 130B of the link portion 30B.

These dimensional characteristics and these geometric ratios allow an excellent compromise to be obtained between the need to ensure good resistance of the retaining wing to axial forces and the need to allow the retaining wing to deform fairly easily under the action of radial forces so as not to consume too much clamping force.

Typically, the free end 30D "of the retaining wing is pointed to provide a generally point support against the inner periphery of the side 12C in the unclamped state of the collar.

Typically, the retaining wings have a triangular shape. To some extent, it has the shape of a skate wing, which is very flexible under radial forces while resisting axial forces. The amount of material from which the retaining wings are made is minimized, which promotes their ability to deform under the clamping force, but the base of the retaining wings is wide enough and the retaining wings are long enough in the radial direction for the retaining wings to perform their axial retaining function and spacer function as long as the collar is not clamped.

The retaining edge 30D' of the retaining wing 30D has a concave shape when viewed radially in fig. 7. This allows an arc-to-arc pivoting movement between the retaining edge of the retaining wing and the edge of the belt side as the edge stretches around to form a convex surface during clamping. This pivoting movement promotes the swinging of the retaining wings during clamping.

In contrast, the edge 30Dl of the retaining wing 30D opposite its retaining edge 30D ″ has a convex shape.

The support lugs may be integrally formed with the gasket in the form of a strip. The support lugs are cut and flattened prior to the successive bends. When flat, the retaining wing may form a triangle, the base of which is attached to the link portion and one side of which intended to form the retaining edge is substantially perpendicular to the longitudinal direction of the link portion, while the other side intended to form the edge opposite the retaining edge is inclined by about 45 ° with respect to the longitudinal direction. When flat, the side of the retaining wing forming the retaining edge may be very slightly concave, for example in the shape of a circular arc with a large radius of curvature, which does not eliminate the overall triangular shape of the retaining wing.

The support lugs also include lugs 32 that also have hooks 32A at their free ends that are opposite the regions where the hooks attach to the outer periphery 22' of the gasket 22. The lugs 32 also include an axial portion 32B that extends substantially axially between the attachment of the lugs to the washer 22 and the hook 32A. These lugs 32 also have hook tabs 32C similar to the tabs 30C described above. Finally, these lugs 32 also comprise centering wings 32D, which are however oriented back to back with the aforementioned retaining wings 30D. In effect, the centering fins 32D are bent radially inward from the longitudinal edges of the axial portion 32B. These centering wings 32D have longitudinal edges 32D' which help to pre-mount the collar on the end of the pipe 1 by holding the gasket with radial clearance with respect to the pipe. The longitudinal edge 32D' may locally have a beveled protrusion to facilitate its bending during clamping.

The metal gasket also has lugs 34, as shown in fig. 1 and 3, the lugs 34 having hooks 34A at their free end positions opposite the outer periphery 22' of the gasket 22, and having axial portions extending from the gasket to the hooks. These lugs serve to wedge the gasket angularly relative to the belt, with the hooks 34A engaged in the notches 13A in the edges 13 of the belt sides 12C.

Typically, the support lugs 30 and 32 are alternately disposed on the outer periphery of the gasket 22. These lugs 30 and 32 serve to hook over the edge 13 of the side 12C of the belt 12 by preventing the seal from moving relative to the belt in a direction opposite to the direction R1 shown in fig. 4. The retaining flap 30D serves to retain the washer relative to the belt by limiting displacement of the washer relative to the belt in the direction R1. These lugs, and also lugs 32, also have a tongue 30C or 32C for retaining the end of the pipe within the gasket. The lugs 32 also have centering fins 32D for centering the tube relative to the gasket.

As can be seen in particular in fig. 3, the supporting lugs 30 and 32 are formed integrally with the metal gasket. In practice, the metal gasket is integrally formed from a strip by cutting, stamping and bending.

In the example shown in fig. 1-4, the metal washer 22 and the non-metal washers 24 and 26 are substantially planar. In practice, the front surfaces 1'a and 2' a of the flanges, on which the bearing surfaces of the ducts 1 and 2 are formed, are oriented radially.

However, as indicated in patents EP 1451498, EP 2598785 or EP 3232107, the collar may be pre-mounted on a pipe whose bearing surface is frustoconical. In this case, as shown in fig. 8, the metal gasket 122 may have a frustoconical surface, in particular a stamped frustoconical surface. The cross-section of fig. 8 shows a seal 120 having a gasket 122 and lugs 30, 32 and 34, the lugs 30, 32 and 34 being similar to the lugs previously described. The belt 112 is similar to the belt 12 except that its sides 112C and 112B may be inclined like branches of a V-shape, adapted to the trumpet shape of the ducts 101 and 102. In practice, the support surface 101A of the duct 101 has a frustoconical shape forming a trumpet shape, and the support surface 102A of the duct 102 has a front face 102'a, which front face 102' a also forms a frustoconical surface so as to adapt to the aforementioned trumpet shape. In the opposite direction, the bearing surface 102A formed at the rear in the direction R2 with respect to the frustoconical portion 102' a is also frustoconical, substantially parallel to the side 112B of the belt 112. As shown, the metal gasket has a stamped frustoconical surface 122A that conforms to the shape of the surfaces 101'a and 102' a of the pipes to which it must be sealed with the seal 120. A portion of the non-metal based washer 124 is formed as a planar ring that deforms to match the frustoconical shape of the frustoconical surface of the metal washer 122.

For example, for an initially flat non-metal based gasket, the angle α formed by the frustoconical surface of the above-mentioned conduit with respect to a direction perpendicular to axis a is about 20 degrees at the maximum. However, it is possible to use non-metal based gaskets which are not initially planar, but which are thus shaped, for example by heating, with a larger angle α, for example about 45 °, particularly if the gasket comprises a thermoformable adhesive.

Unlike the metal washer 22, the non-metal based washer 24 may be fully annular, without retaining lugs or the like. The non-metal based gasket is carried by a metal gasket 22. It can be fixed to the metal washer 22 in different ways. For example, it may be fixed to the metal washer by adhesion. The non-metal based gasket 24 may be supported by the metal gasket 22 by purely mechanical means that do not require external materials such as glue. Thus, the metal gasket may carry a retaining lug that cooperates with the non-metal based gasket to retain the non-metal based gasket relative to the metal gasket. Thus, as can be seen in fig. 1 and 5, the metal washer 22 has a lug 36 formed by a cut-out in the washer which is slightly straightened axially to form a tongue whose free end is oriented towards the axis a. These retaining lugs 36 thus serve to wedge and retain the non-metal based washer 24 by engaging the outer radial edge 24A of the non-metal based washer 24. Likewise, as shown in fig. 2 and 6, the metal washer 22 has a retention lug 38 similar to the retention lug 36, but axially oriented on the other side to retain the non-metal based washer 26 on the other face of the washer 22.

The metal washer 22 may have an annular projection or generally an annular relief to provide it with axial deformability. For example, in fig. 3, it can be seen that gasket 22 has an annular bead 22A projecting on one face thereof against which a non-metal based gasket 24 is disposed. The non-metal based gasket 24 or 26 may be planar or have an annular protrusion 24A. A portion of the gasket 26 may have an annular projection 26A.

Fig. 9 shows an example in which the non-metal based washer 124 is actually formed of two base washers, 123 and 123', respectively, that are secured together, for example by gluing. Each of these base washers 123 and 123' has an annular projection 123A and 123B, respectively. Thus, the gasket 124 has an annular projection not only on its first face facing the metal gasket 22, but also on the opposite second face. The annular projections 123A and 123B are disposed on the same radial dimension so as to form an annular space 124' therebetween. It can also be seen in fig. 9 that the metal washer 22 has an annular projection 22A projecting on a first face thereof against which the washer 124 is disposed so that the annular projections 22A and 123A are disposed against one another.

The metal gasket 22 may have corrugations or deformations that form micro-folds 22B (see fig. 7) instead of a purely convex annular protrusion.

In the example just described, the washer 20 includes a metallic portion 22 and a non-metallic portion 24 or 124. However, the gasket may be one-component, and in particular formed only by the metal part 22.

The present invention is particularly concerned with the support lug 30 and its retaining wing 30D. The lugs and the wings are usable for hooking the lateral surface of the belt, by performing the axial retention function of the washer by retaining it in both axial directions with respect to the belt, and by performing the spacer function by forming, between the annular portion of the washer and the inner surface of the lateral surface of the belt, an annular space into which the end of the pipe can be inserted to pre-mount the clamping system on the pipe.

By performing these two functions on the same support lug, its efficiency can be optimized. It is in fact possible to select the number and angular distribution of the supporting lugs according to the desired axial resistance. There may be more support lugs than in EP 1451498, since it is not necessary to retain position for the internal lugs that are only used to hold the washer against displacement of the collar in the direction R1.

With their inner projections (tongues) 30C, these support lugs 30 also perform the function of axially retaining the pipe in the collar.

As shown, the gasket may also carry lugs 32 which also serve to hook onto the belt. These lugs 32 also serve to centre the clamping system on the pipe due to the centring wings 32D.

The same lug may have both a retaining wing bent outwards in the type of retaining wing 30D and a centering wing bent inwards in the type of centering wing 32D. The lug then combines the axial retention function of the washer and the spacer function described above. If a tongue 30C type of inner protrusion is further provided, it further ensures the axial retention function of the pipe. Such a multi-functional lug 230 is shown, for example, in fig. 10. Having a hook 230A, a link portion 230B, a tab 230C, a retaining wing 230D similar to that in support ledge 30, and a centering wing 232D similar to that in ledge 32. As can be seen in particular, the retention wing 230D has a retention edge 230'D similar to the retention edge 30' D, and the centering wing 232D has a longitudinal centering edge similar to the edge 32D. In this case, the holding wing 230D and the centering wing 232D are formed on two opposite edges of the link portion. The retaining wing 230D has the same geometric features and the same dimensional ratios as the previously described retaining wing 30D.

The lugs 30 and 32 or the lug 230 may have the same length, which simplifies manufacturing. The angled wedging lugs 34 of the washer may also have the same length, if present.