A clamping system for connecting pipes, comprising a collar and a washer with support protrusions.
The clamping system optimizes pipe connection by using a support projection with a hook and retaining wing to maintain axial position and spacing, addressing manufacturing complexity and enhancing clamping efficiency.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- CAILLAU
- Filing Date
- 2026-03-10
- Publication Date
- 2026-06-02
AI Technical Summary
Existing clamping systems for connecting pipes require complex geometric shapes and manufacturing steps due to the use of multiple types of projections to maintain the axial position and centering of the washer relative to the collar.
A clamping system with a collar and washer that utilizes a support projection with a hook and a bent retaining wing to hold the washer in two opposite axial directions, minimizing radial space requirements and optimizing the biaxial holding and spacer functions, allowing for efficient pre-mounting on the pipe.
The system achieves efficient clamping by minimizing radial deformation of the retaining wing, ensuring effective axial holding and spacing without excessive force consumption, thus simplifying manufacturing and enhancing clamping efficiency.
Smart Images
Figure 2026090642000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a clamping system for connecting a first and a second pipe, the opposing ends of these pipes having bearing surfaces that project with respect to the cylindrical outer surfaces of these pipes, the clamping system comprising a collar and a washer, said collar being capable of being clamped around the bearing surface of said pipe.
Background Art
[0002] Patent Document 1, Patent Document 2, and Patent Document 3 disclose a clamping system comprising a collar having a belt that can be clamped by reducing its diameter, and a washer pre-attached to this collar. More specifically, this system comprises a washer including a closed annular portion forming a seal, and a projection connecting this seal to the collar. The washer is first held against the belt of the collar such that an annular space is formed between the annular portion of the washer and the inner peripheral surface of the belt to enable engagement between the end of the pipe and the annular portion of the washer. Then, the inner pipe itself is engaged so as to contact the annular portion of the washer. This device is particularly suitable for clamping two pipes fitted to each other and has a radially projecting surface used as a bearing for the clamping collar. The clamping collar comprises a recess capable of accommodating these radially projecting surfaces, and the annular portion of the washer has a shape adapted to these projecting surfaces.
[0003] In particular, the washer, like the belt of the collar, can be made of a stainless steel type of metal.
[0004] In the above patents, particularly in Patent Documents 1 and 2, in the unclamped state, the washer is held in place relative to the collar by different types of projections. Some projections are internal projections, which are fully housed inside the belt and are in the form of radially raised tabs to apply pressure to the inner circumferential surface of one side of the belt, holding the washer against axial displacement of the collar in a first direction outward from this side. Other projections, longer than the internal projections, are hook-shaped, with their heads protruding outward beyond the edge of the side of the belt to hook onto, in order to hold the washer against axial displacement in the opposite direction. Thus, these two types of projections maintain the axial position of the washer relative to the collar and ensure the existence of the aforementioned annular space before the collar is clamped. Other projections are also used for centering the washer relative to the collar.
[0005] While these systems are satisfactory, equipping these different types to protruding washers requires relatively complex geometric shapes and different types of manufacturing steps. [Prior art documents] [Patent Documents]
[0006] [Patent Document 1] European Patent No. 1451498 [Patent Document 2] European Patent No. 2598785 [Patent Document 3] European Patent No. 3232107 [Overview of the Initiative] [Problems that the invention aims to solve]
[0007] This disclosure aims to overcome the aforementioned shortcomings, at least substantially. [Means for solving the problem]
[0008] Accordingly, the present disclosure relates to a clamping system for connecting first and second pipes, wherein the opposing ends of the pipes have bearing surfaces projecting toward the cylindrical outer surface of the pipes, the system comprising a clampable collar and a washer, the collar comprising a belt which can cooperate with the bearing surface by an inner circumferential surface defining a recess into which the bearing surface can be inserted, the washer comprising a support projection having an annular portion disposed within the belt and a hook configured to engage with the edge of the belt, and a connecting portion extending between the annular portion and the hook, the connecting portion comprising a support projection having a retaining edge bent radially outward and spaced apart from the hook, the retaining wing having a width measured axially, the width decreasing toward its free end, and the edge of the belt being accommodated in a space formed between the retaining edge and the hook.
[0009] Therefore, by using the same support projection, it is possible to pre-mount the clamping system on the pipe by both holding the washer against the collar in two opposite axial directions via its hook and bent retaining wing, and maintaining the annular space necessary for engagement of the pipe end between the washer and the adjacent side of the belt. Thus, the biaxial holding function and spacer function of the washer are performed. According to this disclosure, the axial width of the retaining wing decreases toward its free end. During clamping of the collar, the support projection, in particular the retaining wing, deforms to allow for effective clamping of the belt on the bearing surface. With the collar clamped to the pipe, it is important to minimize the radial space requirements of the support projection, in particular the retaining wing. This deformation of the retaining wing reduces its radial height by folding it radially inward, for example, as if the retaining wing were unfolding toward the connecting portion that supports it. Some of the force applied to clamp the collar is consumed to cause deformation of the retaining wing and therefore does not directly contribute to the clamping force of the belt on the bearing surface. The applicant has found that reducing the width of the free end of the retaining wing makes the retaining wing more sensitive to radial deformation forces. In other words, due to its specific shape, the retaining wing begins to deform with moderate force, and once deformation begins, it continues as the collar clamping continues without consuming most of the clamping force. Thus, the retaining wing has sufficient width at its base to withstand axial deformation and perform its biaxial retaining function of the washer and its spacer function, but deforms during the clamping of the collar without consuming most of the force applied to the clamp. The width of the retaining wing does not have to decrease continuously from its base, but at least in the region of its outer radial free end, the retaining wing has a width that decreases as it extends radially outward to this free end. However, it is advantageous for the width of the retaining wing to decrease from its base to its free end.
[0010] If necessary, the retaining wings have a triangular shape.
[0011] If necessary, the width of the retaining wing at its free end is no more than 1 / 4 of the width of the retaining wing at its base, and if necessary, it is no more than 1 / 10 of the width at its base.
[0012] If necessary, the width of the retaining wing at the free end shall be no more than 1 / 5 of the length of the connecting section, and if necessary, no more than 1 / 15 of the length of the connecting section.
[0013] If necessary, the width of the retaining wing at its base should be no more than one-third of the length of the connecting section.
[0014] If necessary, the free end of the retaining wing forms a tip.
[0015] If necessary, the retaining edge of the retaining wing has a concave shape when viewed radially.
[0016] If necessary, the edge of the retaining wing opposite the retaining edge may be convex when viewed radially.
[0017] If necessary, the connecting portion has retaining wings on each of its two edges.
[0018] If necessary, the support projection has an inner projection configured to grip the bearing surface of the pipe inserted into the collar.
[0019] If necessary, the inner projection is supported at the connection portion and includes a tab that is bent radially inward relative to the connection portion.
[0020] If necessary, the tabs are cut at the connection points.
[0021] If necessary, the tab can be oriented away from the hook.
[0022] Where necessary, the connection portion extends substantially axially.
[0023] If necessary, the support projection is formed integrally with the annular portion.
Brief Description of the Drawings
[0024] [Figure 1] FIG. 1 is a perspective view of a clamp system according to the present disclosure, viewed from a first side. [Figure 2] FIG. 2 is a perspective view of the system shown in FIG. 1, viewed from the opposite side. [Figure 3] FIG. 3 is an exploded perspective view showing the various elements that make up the individually shown clamp system and the ends of two pipes assembled using this system. [Figure 4] FIG. 4 is an axial cross-sectional view in plane IV of FIG. 1, showing on the one hand the clamp system according to the present disclosure and on the other hand the ends of two pipes assembled using this clamp system. [Figure 5] FIG. 5 is an enlarged view of detail V of FIG. 1. [Figure 6] FIG. 6 is an enlarged view of detail VI of FIG. 2. [Figure 7] FIG. 7 is a view of detail VII of FIG. 4. [Figure 8] FIG. 8 is an axial partial cross-sectional view of a modification, viewed in the same way as FIG. 4. [Figure 9] FIG. 9 is a partial perspective view showing a modification of the seal. [Figure 10] FIG. 10 shows a modification of the support projection.
Modes for Carrying Out the Invention
[0025] FIG. 1 shows a clamp collar 10 having a belt 12 whose ends are radially raised to form a clamp projection 12A and a clamp projection 12B, respectively. To clamp the collar, the diameter of the belt is reduced by the cooperation of a clamp screw 14 with the clamp projection 12A and the clamp projection 12B. The shank 14B of the screw passes through the bore of the clamp projection, the head 14A cooperating with the projection 12A, and the opposite end where a nut 14C cooperating with the projection 12B here via a spacer 14D is provided.
[0026] The belt 12 has an inner recess 15 (more clearly shown in Figure 4) formed between two sides of the belt, 12C and 12D, respectively. In this disclosure, a washer 20 forming a seal is positioned within the belt. As is best seen in Figure 4, the clamping system is used to connect two pipes 1 and 2, the ends of which are provided with bearing surfaces 1A and 2A. To connect the pipes, these ends are joined until they are axially positioned within the recess 15, and the diameter of the belt is reduced so that sides 12C and 12D are clamped to bearing surfaces 1A and 2A. In this disclosure, bearing surfaces 1A and 2A are formed on radial flanges present at the ends of pipes 1 and 2.
[0027] Hereafter, the washer 20 will be referred to as a seal, but this sealing function is only one example of the washer's functions. It is primarily used to pre-install a collar on one of the pipes. As shown, the seal 20 is located inside the collar. For the connection of pipes 1 and 2, the front surfaces 1'A and 2'A of the ends of pipes 1A and 2A are positioned on either side of the annular sealing portion 21 present within the seal 20.
[0028] In the sense of this disclosure, the forward direction of pipe 1 or pipe 2 is the direction toward the other pipe 2 or pipe 1 when connecting their ends to assemble the pipes. Accordingly, bearing surfaces 1A and 2A are formed on the rear surfaces of the radial flanges present at the ends of the pipes. The rear direction is obviously the opposite direction. For a single element, the inward direction is toward axis A, and the outward direction is the opposite.
[0029] In this disclosure, the annular sealing portion comprises a metal washer 22 and a non-metallic washer 24 fixed to the metal washer. In this disclosure, as can be understood by considering Figures 1, 2, and 3 together, the annular sealing portion comprises a metal washer 22, a non-metallic washer 24 positioned on the first surface of the metal washer, and another non-metallic washer 26 positioned on the other surface of the metal washer. Thus, the metal washer is sandwiched between the non-metallic washer 22 and the non-metallic washer 24.
[0030] For example, the metal washer 22 can be manufactured from the same metal as the belt 12, such as stainless steel. The non-metallic washers 24 and 26 can be formed from composite materials such as mica-based materials.
[0031] Non-metallic washers 24 and 26 are supported by a metal washer 22. As can be seen in Figures 1 to 3, the metal washer 22 supports a support projection, through which the metal and non-metallic washers are supported on the collar 10. In this way, the seal is pre-attached to the belt. That is, the seal is supported on the collar so that the collar and seal can be handled as a single unit before the collar is placed on the pipe and clamped.
[0032] Furthermore, the metal washer can also carry a support projection for pre-attaching a collar with the washer to one of the pipes being assembled. Thus, the assembly formed by the collar and seal can be positioned at one end of the pipe and held in place before the other end of the pipe is positioned and clamped. The same projection can have a dual function: pre-attaching the seal to the belt and pre-attaching the assembly formed by the collar and seal to one end of the pipe. These support projections are located on the outer circumference of the metal washer 22 (away from the belt axis A).
[0033] Three different types of projections are shown in this disclosure. As is best seen in Figures 7 and 9, the support projection 30 has a curved end 30A that can hook onto the edge 13 of the side surface 12C of the belt 12. Between the connection region of the outer circumference 22' of the metal washer 22 and this hook 30A, these projections 30 have a connecting portion 30B that extends substantially axially in this disclosure, i.e., substantially parallel to axis A. As is best seen in Figure 7, this connecting portion 30B has a hooking tab 30C that is cut out at the connecting portion 30B and bent radially inward, extending from the hook 30A toward the outer circumference of the metal washer 22' toward its free end. This tab 30C is used to grip the washer on the bearing surface 1A of the pipe 1 and holds a collar pre-installed at the end of the pipe. The orientation of this tab 30C away from the hook 30A prevents the pipe from being released rearward from the washer relative to the pipe 1, along arrow R1 shown in Figure 4. The tab 30C of projection 30 is an example of an inner projection configured to grip the bearing surface 1A inserted into the collar.
[0034] Furthermore, the support projection 30 has retaining wings 30D that are bent radially outward from the longitudinal edge of the connecting portion 30B, i.e., bent away from axis A. In addition, these retaining wings 30D have retaining edges 30D' which face toward the inner surface of the hook 30A and therefore toward the inner surface of the side surface 12C of the belt 12 when the seal is pre-fitted onto the washer. These retaining edges 30D' are spaced apart from the inner surface of the hook 30A. The edge 13 of the side surface 12C is thus accommodated in the space formed between the hook 30A and the retaining edges 30D. This allows the metal washer 22 to be held against the belt of the collar by holding the metal washer 22 in both axial directions.
[0035] The above diagram shows that the connecting portion 30B has retaining wings 30D on each of its two longitudinal edges 30B' (substantially parallel to axis A), but it is also possible to have only one retaining wing.
[0036] From Figure 7, it can be seen that the retaining wing 30D has a width l30D measured in the axial direction, which decreases toward its free end 30D''. Thus, during clamping of the collar, the retaining wing 30D tends to slide naturally against the inner circumferential surface of the side 12C, bending and collapsing without interfering with the clamping.
[0037] The width of the retaining wing at the free end is very small, and it can be seen that it is in almost point contact with the inner circumferential surface of the side surface 12C when the collar is not clamped. The width of the retaining wing at the free end is less than 1 / 4 of the width of the retaining wing at the base 30D'', and this base is part of the retaining wing that is attached to the connecting portion 30B that supports the retaining wing. The width of the retaining wing at its free end 30D'' is less than 1 / 10 of its width at its base 30D'''.
[0038] The width of the retaining wing 30D at the free end 30D'' is less than or equal to 1 / 5 of the length l30B of the connecting portion 30B, where l30B is measured axially. The width of the retaining wing 30D at the free end 30D'' is less than or equal to 1 / 15 of the length l30B of the connecting portion 30B.
[0039] The width of the retaining wing 30D at the base 30D''' is less than or equal to 1 / 3 of the length l30B of the connecting portion 30B.
[0040] The characteristics of these dimensions and their geometric ratios allow for an excellent compromise between the need to ensure that the retaining wing has good resistance to axial forces and the need to deform very easily under the influence of radial forces inward, thereby preventing excessive clamping force consumption.
[0041] Generally, the free end 30D'' of the retaining wing forms a tip and, in the unclamped state of the collar, provides substantially point support to the inner circumferential surface of the side 12C.
[0042] Generally, retaining wings have a triangular shape. In a sense, retaining wings have the shape of a skate wing and bend very easily under radial forces while resisting axial forces. The amount of material from which the retaining wing is formed is kept to a minimum, which facilitates its ability to deform under clamping forces, but the base of the retaining wing is wide enough, and unless the collar is clamped, the retaining wing is radially long enough to perform its axial retaining and spacer functions.
[0043] As shown in Figure 7, when viewed radially, the retaining edge 30D' of the retaining wing 30D has a concave shape. This allows for arc-to-arc pivoting between the retaining edge of the retaining wing and the edge of the belt's side surface when the retaining edge expands radially to form a convex surface during clamping. This pivoting facilitates the flap motion of the retaining wing during clamping.
[0044] Conversely, the edge 30D1 of the retaining wing 30D on the opposite side of the retaining edge 30D'' has a convex shape.
[0045] The support projection may be formed integrally with the washer in the strip. It is initially cut and flattened before being folded in a continuous manner. When flattened, the retaining wing forms a triangle, with its base attached to the connecting portion, and its side for forming the retaining edge is substantially perpendicular to the longitudinal direction of the connecting portion, while the other side for forming the edge opposite the retaining edge is inclined at approximately 45° with respect to this longitudinal direction. When flattened, the side of the retaining wing for forming the retaining edge may be very slightly concave, for example, having the shape of a circular arc with a large radius of curvature, without precluding the overall triangular shape of the retaining wing.
[0046] The support projection further comprises projections 32 which also have a hook 32A at the free end opposite to the mounting area 22' of the outer circumference of the washer 22. These projections 32 also have axial portions 32B that extend substantially axially between the attachment of these projections to the washer 22 and the hook 32A. These projections 32 also have hooking tabs 32C similar to the tabs 30C described above. Finally, these projections 32 also have centering wings 32D, but these centering wings 32D are oriented opposite to the retaining wings 30D described above. In fact, the centering wings 32D are bent radially inward from the longitudinal edge of the axial portion 32B. These centering wings 32D have longitudinal edges 32D' which contribute to the pre-attachment retention of the collar to the end of the pipe 1 by holding the washer against the pipe with respect to the radial clearance. The longitudinal edge 32D' may have locally tapered projections to facilitate folding during clamping.
[0047] The metal washer has projections 34, as can be seen in Figures 1 and 3, which have hooks 34A at the free end opposite the outer circumference 22' of the washer 22 and an axial portion extending from the washer to these hooks. These projections are used as an angle wedge of the washer relative to the belt, and the hooks 34A engage with notches 13A present on the edge 13 of the side surface 12C of the belt.
[0048] Generally, the support projections 30 and 32 are arranged alternately on the outer circumference of the washer 22. These projections 30 and 32 are used to hook onto the edge 13 of the side 12C of the belt 12 by preventing the seal from moving relative to the belt in the direction opposite to the direction of R1 shown in Figure 4. The retaining wing 30D is used to hold the washer relative to the belt by limiting the displacement of the washer in the direction of R1. These projections, like projections 32, also have tabs 30C or tabs 32C used to hold the end of the pipe inside the washer. Projection 32 also has a centering wing 32D used to center the pipe relative to the washer.
[0049] As can be seen in Figure 3, the support projections 30 and 32 are formed integrally with the metal washer. In fact, this metal washer is formed integrally from a strip by cutting, stamping, and folding.
[0050] In the examples shown in Figures 1 to 4, the metal washer 22 and the non-metallic washers 24 and 26 are substantially planar. In fact, the front surfaces 1'A and 2'A of the flanges formed on the bearing surfaces of pipes 1 and 2 are oriented radially.
[0051] However, as illustrated in, for example, Patent Document 1, Patent Document 2, or Patent Document 3, the collar can be pre-mounted on a pipe whose bearing surface is frustoconical. In this disclosure, as can be seen in Figure 8, the metal washer 122 may have a frustoconical surface, particularly a stamped frustoconical surface. The cross section of Figure 8 shows the washer 122 and the seal 120 having projections 30, 32, and 34, similar to the projections described above. The belt 112 is similar to belt 12, except that its sides 112C and 112B may be inclined like V-shaped branches to conform to the flared shapes of pipes 101 and 102. In fact, the bearing surface 101A of pipe 101 has a frustoconical shape that forms a flared shape, and the bearing surface 102A of pipe 102 has a front surface 102'A, which also forms a frustoconical surface to conform to the aforementioned flared shape. The bearing surface 102A, formed posteriorly in the direction of R2 relative to the frustoconical portion 102'A, is also frustoconical in the opposite direction and substantially parallel to the side surface 112B of the belt 112. As shown, the metal washer has a stamped frustoconical surface 122A that conforms to the shape of the pipe surfaces 101'A and 102'A, and the pipe connection must be sealed using the seal 120. The non-metallic washer 124 is formed in a planar ring that is deformed in part to conform to the frustoconical shape of the frustoconical surface of the metal washer 122.
[0052] The angle α formed by the aforementioned frustoconical surface of the pipe in a direction perpendicular to axis A is, for example, up to about 20 degrees for a non-metallic washer that is initially planar. However, if a non-metallic washer that is not initially planar but is formed so by heating, for example, is used, especially in the case of a washer made of a thermoformable binder, it is possible to have a larger angle α, for example, about 45°.
[0053] Unlike the metal washer 22, the non-metallic washer 24 does not have fixing protrusions and may be purely annular. The non-metallic washer is supported on the metal washer 22. It can be fixed to the metal washer 22 in different ways. For example, it can be fixed to the metal washer by adhesive. The non-metallic washer 24 can be supported on the metal washer 22 by purely mechanical means that do not require external materials such as adhesives. Thus, the metal washer can carry retaining protrusions that cooperate with the non-metallic washer to hold the non-metallic washer relative to the metal washer. Thus, in Figures 1 and 5, it can be seen that the metal washer 22 has protrusions 36, which are formed by a cutout in the washer and are slightly straightened axially to form a tab with its free end facing axis A. These retaining protrusions 36 are therefore used to wedge and hold the non-metallic washer 24 by cooperating with their outer radial edge 24A. Similarly, as can be seen in Figures 2 and 6, the metal washer 22 has retaining protrusions 38 similar to the retaining protrusions 36, but the retaining protrusions 38 are oriented axially opposite to each other in order to hold the non-metallic washer 26 located on the other side of the washer 22.
[0054] The metal washer 22 may have an annular bulge or a generally annular relief that provides axial deformation capability. For example, in Figure 3, it can be seen that the washer 22 has an annular bead 22A protruding from one of its faces, and a non-metallic washer 24 is positioned opposite it. The non-metallic washer 24 or non-metallic washer 26 may be planar or may have an annular bulge 24A. The washer 26 may have an annular bulge 26A on a part of it.
[0055] Figure 9 shows an example in which a non-metallic washer 124 is actually formed by two elementary washers 123 and 123' fixed to each other, for example, by adhesive. These elementary washers 123 and 123' have annular bulges 123A and 123B, respectively. Thus, the washer 124 has annular bulges not only on the first surface facing the metal washer 22, but also on the second opposite surface. The annular bulges 123A and 123B are positioned on the same diameter dimension so as to form an annular space 124' between them. Figure 9 also shows that the metal washer 22 has an annular bulge 22A that protrudes from the first surface on which the washer 124 is placed, and as a result, the annular bulge 22A and the annular bulge 123A are positioned facing each other.
[0056] Instead of a purely convex annular bulge, the metal washer 22 may have a wavy or deformed shape that forms a slight fold 22B (see Figure 7).
[0057] In the example described above, the washer 20 comprises a metal portion 22 and a non-metal portion 24 or a non-metal portion 124. However, the washer may be a single unit, and in particular, it may be formed from only the metal portion 22.
[0058] This disclosure focuses particularly on the support projections 30 and their retaining wings 30D. These projections and wings are used to hook onto the side of a belt and serve to axially hold the washer in both axial directions relative to the belt, and to form an annular space between the annular portion of the washer and the inner surface of the side of the belt into which the end of the pipe can be inserted, thereby serving as a spacer for pre-mounting the clamp system to the pipe.
[0059] By performing these two functions with the same support protrusions, the efficiency is optimized. In fact, it is possible to select the number and angular distribution of support protrusions as the desired axial resistance function. Since it is not necessary to secure the position of internal protrusions used solely for holding the washer in relation to the R1 direction displacement of the collar, it is possible to have more support protrusions than in Patent Document 1.
[0060] Along with their inner protrusions (tabs) 30C, these support protrusions 30 also serve the function of axially holding the collar pipe.
[0061] As described above, the washer may further have projections 32 which are also used for hooking onto the belt. These projections 32 are also used for centering on the pipe of the clamp system by the centering wings 32D.
[0062] The same projection can have both a retaining wing folded outward, type 30D, and a centering wing folded inward, type 32D. This projection then combines the axial holding function of the washer and the spacer function described above. Furthermore, if an inner projection of type 30C tab is provided, an axial holding function of the pipe is also ensured. For example, such a multifunctional projection 230 is shown in Figure 10. This multifunctional projection 230 has a hook 230A, a connecting portion 230B, a tab 230C, and a retaining wing 230D similar to those of the support projection 30, and a centering wing 232D similar to those of projection 32. It can be seen in particular that the retaining wing 230D has a retaining edge 230'D similar to the retaining edge 30'D, and the centering wing 232D has a longitudinal centering edge similar to the edge 32D. In this configuration, the retaining wing 230D and the centering wing 232D are formed on the two opposing edges of the connecting portion. The retaining wing 230D has the same geometric properties and dimensional ratio as the retaining wing 30D described above.
[0063] The projections 30 and 32, or projection 230, may have the same length, thereby simplifying manufacturing. The angle wedge projection 34 of the washer, if present, may also have the same length.
Claims
1. A clamping system for connecting first and second pipes (1, 2), wherein the opposing ends of the pipes have bearing surfaces (1'A, 2'A) protruding from the cylindrical outer surface of the pipes, the clamping system comprises a clampable collar (10) and a washer (20), the collar having a belt (12) that can cooperate with the bearing surface by an inner circumferential surface defining a recess (15) into which the bearing surface can be inserted, and the washer (20) having an annular portion (22) disposed within the belt and configured to catch on the edge (13) of the belt. A support projection (30) is supported, having a hook (30A) and a connecting portion (30B) extending between the annular portion (22) and the hook (30A). The connecting portion supports at least one retaining wing (30D) having a retaining edge (30D') bent radially outward and spaced apart from the hook. The retaining wing (30D) has a width (l30D) measured in the axial direction, the width decreasing toward its free end (30D''), and the edge portion (13) of the belt is housed in the space formed between the retaining edge and the hook. A clamping system in which the width of the retaining wing (30D) at the free end (30D'') is 1 / 10 or less of the width of the retaining wing (30D) at the base (30D''').
2. The clamping system according to claim 1, wherein the retaining wing (30D) has a triangular shape.
3. The clamping system according to claim 1 or 2, wherein the width of the retaining wing (30D) at the free end (30D'') is 1 / 5 or less of the length (l30B) of the connecting portion (30B).
4. The clamping system according to any one of claims 1 to 3, wherein the width of the retaining wing (30D) at its base (30D''') is 1 / 3 or less of the length (l30B) of the connecting portion (30B).
5. The clamping system according to any one of claims 1 to 4, wherein the free end (30D'') of the retaining wing forms a tip portion.
6. The clamping system according to any one of claims 1 to 5, wherein the connecting portion (30B) has retaining wings (30D) on each of its two edges (30B').
7. The clamping system according to any one of claims 1 to 6, wherein the support projection has an inner projection (30C) configured to grip the bearing surface of the pipe inserted into the collar, and the inner projection is supported on the connecting portion (30B) and comprises a tab (30C) bent radially inward relative to the connecting portion.
8. The clamping system according to any one of claims 1 to 7, wherein the connecting portion (30B) extends in the axial direction.
9. The clamp system according to any one of claims 1 to 8, wherein the support projection (30) is formed integrally with the annular portion (22).
10. The clamping system according to any one of claims 1 to 9, wherein at least one of the support projections is bent radially inward and has a centering wing with a longitudinal edge.