An assembly comprising a first tube and a clamping system connecting the first tube to a second tube

Abstract

An assembly comprises a first tube and a clamping system for connecting the first tube to a second tube, the opposite ends of the first tube and the second tube having clamping surfaces protruding from the cylindrical outer surfaces of the tubes, the clamping system comprising a collar, the collar comprising a band capable of being clamped around the clamping surface, the band having a first side and a second side, an inner groove capable of receiving the clamping surface being defined between the first side and the second side, the collar of the clamping system carrying at least one fixing finger, the fixing finger having a free end portion protruding axially beyond the edge of the first side, the free end portion having a rib configured to be fixed to the outside of the band by radially protruding elements, at least one centering surface axially located outside the edge of the first side being formed on the fixing finger, the first tube further having a fixing portion located on the other side of its clamping surface relative to its free end, the fixing portion forming a fixing protrusion, the rib cooperating with the fixing protrusion when the first tube is assembled into the collar.

Description

Technical Field

[0001] The present disclosure relates to an assembly including a first tube and a clamping system for connecting the first tube to a second tube. Background Art

[0002] Clamping systems of this type are known, for example, from European patents EP 1 4514 498 and EP 2 598 785.

[0003] In such a system, the collar comprises a band capable of being clamped around a clamping surface of a tube. The band has sides between which an internal groove is defined, into which the clamping surface of the tube is placed for clamping. Thus, the tubes are held clamped relative to each other. As shown in the above patent, it may be useful to pre-install the clamping system on the end of at least one tube before clamping.

[0004] In order to allow pre-installation on two tubes, EP 2 598 785 proposes a clamping system comprising a washer fixed relative to a collar by means of a fastening lug, and comprising a first and a second pre-installation lug, said first and second pre-installation lugs being able to cooperate respectively with the first and second tubes to fix the washer relative to the corresponding clamping surfaces of the tubes before clamping, and thus to fix the entire clamping system. In this case, these pre-installation lugs comprise short lugs extending rearwardly above the truncated conical annular shape of the washer to cooperate with the clamping surface of the tube placed between the band and the washer. These pre-installation lugs also comprise long lugs extending from the top of the washer in a direction opposite to the washer to cooperate with the clamping surface of the other tube.

[0005] In EP 2 598 785, both types of lugs are elastically deformable. This arrangement is generally satisfactory, but for certain applications it is important to improve the reliability of the fixation of the lug relative to the clamping surface, in particular for long lugs. In practice, for particularly long lugs, it may be difficult to ensure the correct range of elastic deformation for certain clamping diameters, in particular for large diameters in the range of 5 cm or more. On the one hand, it is necessary to ensure that the elastic modulus of these lugs is high enough so that they have the ideal elasticity so that after the deformation of the tube when it is engaged in the clamping system, they can elastically return to a position to ensure the pre-installation retention of the tube. Then, they must have the necessary elastic response so that they are not too easily deformed when a traction force is applied in the direction of the tube being separated from the clamping system. However, this elastic retention force is only useful in the pre-installation state, before clamping. In the clamping state, on the contrary, it is desired that the lug deforms to press into the band of the collar without affecting the clamping quality. However, if the elastic modulus of the lug is very high, in some cases, in particular for large diameter collars, the latter property may be difficult to achieve. Furthermore, if the modulus of elasticity is too high, the engagement thrust forces required to clamp the lugs on the clamping surface of the tube may be high and difficult to achieve in the final installation situation.

[0006] Therefore, although the system of EP 2 598 785 is satisfactory for a large number of applications, it is desirable to propose another solution allowing the pre-installation of a clamping system at the end of the first pipe substantially without the above-mentioned disadvantages, in particular for large diameter collars.

[0007] EP 1 451 498 proposes a system allowing pre-installation relative to a tube, using pre-installation lugs also performed by the belt through washers provided with the belt. The same problems as those described above may also occur in pre-installation relative to a single tube.

[0008] Other clamping systems are also known, comprising a collar and a washer carried by the collar, the washer having an internal lug capable of being clamped inside one of the tubes for pre-mounting the clamping system at the end of that tube. This may be useful to complete the system, also allowing pre-mounting relative to another tube. For this purpose, the long lug proposed by EP 2 598 785 may be used, but in particular for large diameter collars, another solution is needed, which does not substantially suffer from the above-mentioned disadvantages. Summary of the invention

[0009] Generally speaking, there is a need for a clamping system which allows a controlled fixing in a pre-installed state of a clamping surface relative to one of the pipes to be clamped.

[0010] Thus, the present disclosure relates to a clamping system for connecting a first tube and a second tube, the opposite ends of which have clamping surfaces protruding from the cylindrical outer surface of the tubes, the system comprising a collar comprising a band capable of being clamped around the clamping surface, the band having a first and a second side defining between them an internal groove capable of receiving the clamping surface, the collar carrying at least one fixing finger having a free end portion protruding axially beyond the edge of the first side, the free end portion having a rib configured to be fixed to the outside of the band by means of radially protruding elements.

[0011] Thus, when the first tube is fitted into the clamping system, the fixing fingers are naturally in a standby state to cooperate with the elements protruding radially therefrom. Thus, once the first tube has been fitted into the clamping system, no special operation is required to achieve fixing.

[0012] Optionally, the clamping system comprises a centering surface axially outside the edge of the first side.

[0013] Optionally, the centering surface comprises at least one centering surface formed on a fixing finger.

[0014] Optionally, the collar carries at least one centering finger protruding axially beyond the edge of the first side, and wherein the centering surface comprises at least one centering surface formed on the centering finger.

[0015] Optionally, the fixing finger has a slope at the end of its free end portion.

[0016] Optionally, the fixing finger has at least one reinforcing rib.

[0017] Optionally, the centering finger has a slope at the end of its free end portion.

[0018] Optionally, the centering finger has at least one reinforcing rib.

[0019] Optionally, the clamping system comprises a washer supported by a collar, said washer comprising an annular portion placed inside the belt and carrying the fixing fingers.

[0020] Optionally, the washer also carries centering fingers.

[0021] Optionally, the ribs are formed on pins cut out in the fixing fingers and are radially deformed.

[0022] The present disclosure also relates to a clamping system and a first tube according to the present disclosure, wherein the first tube has a clamping surface protruding from its cylindrical outer surface near its free end, and the first tube further has a fixing protrusion located on the other side of the clamping surface relative to its free end, and when the first tube is assembled into the collar, the rib cooperates with the fixing protrusion.

[0023] Optionally, a fixing protrusion is formed on the transverse blade, the transverse blade having a fastening portion, by which it is fastened to the first tube, and a fixing portion which is radially straightened relative to the fastening portion.

[0024] Optionally, the blade has two fixing portions and the collar carries two fixing fingers configured to cooperate with the fixing portions.

[0025] Optionally, the securing projection is configured to define an angular wedging of the clamping system relative to the first tube.

[0026] Optionally, the blade has two shoulders forming radial stops for the fixing fingers.

[0027] The present disclosure will be clearly understood and its advantages will better appear on reading the following detailed description of one embodiment presented by way of non-limiting example. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a perspective view of an assembly including a clamping system according to the present disclosure and two tubes.

[0029] Figure 2 A side view of two tubes preassembled by means of a clamping system is shown.

[0030] Figure 3 is similar to Figure 1 A variation is shown in FIG.

[0031] Figure 4 A first tube suitable for this variation is shown.

[0032] Figure 5 is a detailed view showing the situation of preassembling two tubes using the clamping system according to this variant.

[0033] Fig. 6A is included Figure 5 Schematic diagram of a half section taken in a plane of the fixed finger, the plane being defined by the axis A and the diameter of the band passing through the fixed finger.

[0034] Figure 6B is similar to Fig. 6A The view used for the variant. DETAILED DESCRIPTION

[0035] First describe Figure 1 and Figure 2 As can be seen in these figures, the clamping system comprises a collar 10 and a washer 28 of the same type as described in EP 2 598 785 , with which the collar cooperates to assemble the two pipes 2 , 4 .

[0036] In the following, a "radially inner" element is understood to be an element oriented towards the axis A of the two tubes placed end to end and is the element closest to this axis A relative to other elements referred to as "radially outer" elements, which are those oriented away from the axis A. It can also be considered that the axis A of the two tubes is also the axis of the collar, more specifically the axis of the collar band, the latter being wound around itself.

[0037] Furthermore, if a second element is located beside a first element, that is, outside of an axial slice occupied by the first element, the second element will be considered "outside" or "axially outside" of the first element.

[0038] The collar comprises a band 12 defining a groove 14 into which bearing surfaces 18, 20 belonging respectively to the first tube 2 and to the second tube 4 can be inserted. This groove and these bearing surfaces have a shape such that the clamping force of the band of the collar forces the ends of the tubes 2 and 4 to approach each other. The groove 14 is defined between a first side 13A and a second side 13B of the band 12, which in this case define the branches of a V visible in axial section. The band 12 thus has an advantageous V-shaped axial section, while the bearing surfaces 18 and 20 have a diameter that increases gradually towards the opposite free ends of the tubes and have, for example, a frustoconical shape.

[0039] The strip 12 has ends, respectively 12A and 12B, which are substantially radially straightened to form bearing lugs. These lugs are perforated to allow the shaft 24A of the clamping screw 24 to pass through them. The head 24B of the screw is wedged relative to one of the bearing lugs, in this case the lug 12B, while the nut 26 is fixed relative to the other bearing lug 12A. It will be understood that the rotation of the nut in the screwing direction brings the bearing lugs closer together, thus reducing the internal diameter of the collar, that is to say allowing the strip to be clamped. Of course, other ways of clamping the strip are also conceivable, such as a hook system, as described in particular in patent application FR 3 008 160.

[0040] The clamping system comprises a washer 28 which is fixed to the collar. The washer may in particular be of the type described in EP 1 451 498 .

[0041] This gasket 28 has a frustoconical annular portion 30 which can be inserted between the opposite ends of the two tubes 2 and 4 when they are joined in the clamping system. In practice, the gasket 28 is fixed by means of the fastening lugs relative to the band, in this case relative to its second side 13B, so that an annular space is arranged between the second side and the gasket. The free end of the second tube 4 carrying its bearing surface 20 is inserted into this annular space in the groove 14, while the free end of the first tube 2 carrying its bearing surface 18 is inserted on the opposite side of the annular space relative to the gasket, that is to say against the inner face of the frustoconical portion 30 of the gasket 28.

[0042] In this case, the end of the tube 4 is an inner flared portion, the inner periphery of which bearing surface 20 forms the flared portion. On the other hand, the free end of the first tube 2 is a male end, which has an outer periphery 23 outside its bearing surface 18, the diameter of which gradually decreases towards the end of the free end. Therefore, the end portion thus formed can be inserted into the flared portion formed at the end of the tube 4 in a substantially form-fitting manner. The frustoconical annular portion 30 of the gasket 28 can have an annular deformation 32, forming a seal between the inner surface of the flared portion and the outer periphery 23.

[0043] The fastening of the washer 28 of the collar 10 and / or the pre-assembly of the clamping system consisting of the collar and the washer on the tube 4 can be carried out in the same way as in EP 1 451 498, namely by means of fastening lugs and / or pre-mounting lugs 34 with which the washer is equipped, which are used to hook the washer on the second side 13B of the belt, while arranging the above-mentioned annular space, as described in EP 1 451 498.

[0044] Other modes of fastening the washer to the collar may be used. For example, the washer may have a fixing ring in which the shank of the screw 24 may engage, or may have one or several fixing lugs that are fixed on the edge of the strip, for example by hooking or by pinching. Likewise, other modes of pre-mounting the clamping system relative to the tube 4 may be used, for example by equipping the washer with internal lugs or studs that engage in the tube 4 so as to rest against the internal surface of the tube 4.

[0045] The collar carries fixing fingers 40 having a free end portion axially protruding beyond the edge of the first side 13A. For each fixing finger, the free end portion has a rib 42 configured to be fixed to the outside of the band by a radially protruding element. As shown below, this radially protruding element is in particular a fixing protrusion fixed to the first tube 2. The inner surface 43 of the common portion of the fixing fingers forms a centering surface, which extends axially beyond the edge of the first side 13A and is radially included in the diameter dimension of this edge. Taken together, the different centering surfaces define a diameter dimension comparable to that defined by the top of the clamping surface 18 of the first tube 2, so as to center the first tube when it is inserted into the clamping system. It can be seen that the collar also carries centering fingers 50, which are similar to the fixing fingers, except that they do not have a rib. However, for the fixing fingers, their inner surface 53 forms the centering surface. It can be seen that the fixing fingers and the centering fingers have ribs 48, which are axially oriented and reinforce these fingers. The fixing and centering fingers are therefore radially responsive, that is, they are relatively inflexible and can deform radially elastically over small radial displacements by having a strong tendency to elastic recovery. The fixing and centering fingers also have flaring ramps 49 at the end of their free ends. These flaring ramps facilitate the insertion of the first tube into the clamping system.

[0046] In this case, the fixing fingers 40 and the centering fingers 50 are carried by the washer 28, which itself is supported by the collar 10, as shown. More specifically, the fixing fingers and the centering fingers are carried by the annular portion 30 of the washer, in this case a frustoconical annular portion, which is placed inside the band 12 of the collar. The fixing fingers and the centering fingers extend forwardly from the leading edge of this annular portion. Within the meaning of the present disclosure, the forward direction is the direction from the second side 13B towards the first side 13A. Thus, the fixing fingers and the centering fingers extend forwardly beyond the leading edge of the side 13A. The forward direction is determined by Figure 1 Indicated by the arrow F in . In the unclamped state of the collar, the fixing and centering fingers may extend substantially axially forwards from the front edge of the annular portion 30 of the washer 28. In particular, they may extend parallel to the axis A, at least in the common portion between their ends. However, in the portion where they are attached to the washer 28, they may be slightly corrugated radially outwards, so as to be closer to the bottom of the groove 14 of the band 12. Moreover, the reinforcing ribs may only start from a short distance from the connection of the fixing and centering fingers to the washer, so as to allow a certain flexibility in this connection between the lug and the washer, while ensuring the responsiveness mentioned above, it being noted that the radially outer surface of the fingers may cooperate with the edge of the first side to promote the elastic return of these fingers radially inwards. It will be understood that, when the collar is clamped, the two tubes are connected at the same time, these portions for connecting the fingers to the washer are deformed by being pressed against the bottom of the groove by the clamping surface 18.

[0047] As in Figure 1 and Figure 2 , it can be seen that the first tube has a fixing projection 62 which projects radially on its outer surface and is located on the other side of the clamping surface 18 relative to the free end 2 ' of this first tube 2. More specifically, the fixing projection 62 is formed on a transverse blade 60 which has a fastening portion 60A and a fixing portion by which it is fastened to the first tube, the fixing portion forming the fixing projection 62 and being straightened radially relative to the fastening portion 60A. In practice, the fastening portion is connected to the fixing portion by a step 60B. In this case, the transverse blade 60 has the shape of a flat blade, the thickness of which is measured radially and the width of which is measured parallel to the axis A of the collar. More specifically, in the example shown, the transverse blade has two similar fixing projections 62, which in this case are placed at the two ends between which the fastening portion 60A extends.

[0048] exist Figure 2 As can be seen in FIG. 4 , each of the two fixing fingers 40 cooperates with one of these fixing protrusions 62 via its rib 42. Figure 2 In the embodiment of the present invention, the two tubes are preassembled and the clamping system is preinstalled at the end of the second tube 4 and at the end of the first tube 2. In this case, a clamping collar is sufficient to complete the assembly of the two tubes. In this way, as described above, the fixing lugs and the centering lugs are deformed under the clamping action without hindering the latter.

[0049] See also Figures 3 to 5 , a variation will now be described. Figure 1 to Figure 2 The clamping system itself is unchanged compared to the clamping system of the embodiment of the present invention. The variation of this variant consists in that said system is combined with a first tube, allowing the clamping system to be wedged relative to the angle of this first tube. In fact, the transverse blades 70 formed on the fixing portion carried by the first tube 2 and forming fixing projections 72 differ slightly from the blades 60 previously described, in that these fixing projections 72 are connected to their fastening portion 70A by steps 70B which extend radially outwards by radially projecting ears 70C. These ears are simply made by folding the transverse blades. As in Figure 5 As can be seen in FIG, the angular spacing of the ears 70C is adjusted so that in the pre-assembled state, the ears extend between two fixing fingers 40 and are fixed by their ribs 42 on the front edge of the fixing projection 72. This allows to ensure the angular wedging of the second tube relative to the clamping system.

[0050] The shaping of the transverse blade 60 or 70 allows a particularly effective preassembly. In fact, as shown, the thickness of the blade is oriented radially, while its width is oriented axially. The fixing finger is fixed on the leading edge of the fixing part of this blade, that is to say the edge farthest from the free end of the first tube. Any force that separates the first tube from the locking system operates parallel to the width of the transverse blade. It is therefore the direction in which this blade is less likely to deform. Preassembly is therefore particularly effective. The ear 70C of the blade 70 forms a shoulder in the form of a radial stop for the fixing finger 40.

[0051] For the installation of the assembly comprising two tubes and the clamping system, the free end of the tube 4 is first engaged in the annular space arranged between the washer 28 and the second side 13B of the strip, so as to pre-install the clamping system around it, and then the free end of the tube 2 is engaged in the clamping system until the free end is reached. Figure 3 and Figure 5 Position shown.

[0052] During the assembly of the first tube into the clamping system, the centering surface allows to cooperate with the top of the clamping surface of this first tube in order to center it relative to the clamping system. This facilitates the correct pre-installation of the clamping system on the first tube and thus centers the two tubes relative to each other. The centering surface can be formed on the fixing finger by one or several centering surfaces formed on the centering finger (if provided). The rib of the fixing finger can be made in a very simple way by a simple partial cutout on the finger to release the folded-back lug to form a radially inwardly folded rib 42. This rib is very simple to manufacture without adding material, while forming an effective claw so that the fixing finger grips on the radially protruding element on the periphery of the first tube.

[0053] Fig. 6A Schematically represented are a first tube 2, a second tube 4, a band 12 of a collar, a washer 28 and a transverse blade 70. The frustoconical portion 30 of the washer 28 is located between the inner surface of the bearing surface 20 of the second tube 4 and the outer surface of the frustoconical end of the first tube 2. On the one hand, the clamping system is pre-mounted on the second tube 4, the pre-mounting lugs 34 of the washer hooking on the one hand on the washer on the band 12 of the collar and bearing on the outer surface of the clamping surface 20 on the other hand. On the other hand, the clamping system is also pre-mounted on the first tube, the fixing fingers 40 being fixed on the fixing projections 72 of the blades 70, the ribs 42 being fixed against the front edge of the fixing projections. In this example, as shown in the previous figures, the fingers pass radially over the fixing projections 72 until they hook on their front edge.

[0054] Figure 6B A variation is shown, which is Fig. 6AThe difference is that the fixing finger 40' passes radially under the fixing part, which in this case is similar to the fixing projection 62. In fact, the fixing finger 40' extends axially forward from the frustoconical part 30 of the gasket, while maintaining a diameter dimension that allows it to pass radially under the fixing part during the insertion of the end of the pipe 2 into the clamping system. Therefore, the radially outwardly directed rib 42' of the finger 40' can hook on the leading edge of the fixing part. The ramp 49' formed at the free end of the finger 40' points inwardly. The fixing finger 40' can also be similar to the fixing finger 40 in the previous figures and in particular have a centering surface and a reinforcing rib.

[0055] As shown, the fixing protrusion 62 can be formed on a transverse blade fastened to the first tube. The blade is a very simple and therefore easy to manufacture geometric element. However, its fastening can be very limited due to the possible contact surfaces between the first tube and the blade. The transverse orientation of the blade promotes effective fixing, since the possible separation forces operate axially and therefore perpendicularly to the main direction of the blade, in which direction the blade is less susceptible to deformation.

[0056] The clamping band and the washer as well as the fingers are preferably made of metal. In particular, the washer can be made of an austenitic stainless steel strip, the thickness of which is particularly comprised between 0.1 mm and 0.5 mm, or even between 0.2 and 0.4 mm.

Claims

1. An assembly comprising a first tube (2) and a clamping system for connecting the first tube (2) to a second tube (4), wherein: The opposite ends of the first tube (2) and the second tube (4) have clamping surfaces (18, 20) protruding from the cylindrical outer surfaces of the tubes, The clamping system comprises a collar (10) comprising a band (12) capable of being clamped around the clamping surface, the band (12) having a first side (13A) and a second side (13B), defining between the first side (13A) and the second side (13B) an inner groove (14) capable of receiving the clamping surface (18, 20), wherein the collar (10) of the clamping system carries at least one fixing finger (40, 40') having a free end portion protruding axially beyond the edge of the first side, the free end portion having a rib (42, 42') configured to be fixed to the outside of the band by means of radially protruding elements, In which, at least one centering surface (43) axially located outside the edge of the first side is formed on the fixing finger, and the first tube (2) further has a fixing portion located on the other side of its clamping surface (18) relative to its free end (2'), and the fixing portion forms a fixing protrusion (62, 72), and when the first tube is assembled in the ring, the rib cooperates with the fixing protrusion.

2. The assembly according to claim 1, wherein The fixing fingers (40, 40') have a slope (49, 49') at the end of their free end portions.

3. The assembly according to claim 1, wherein: The fixing finger (40, 40') has at least one reinforcing rib (48).

4. Assembly according to claim 1, comprising a washer (28) supported by said collar (10), said washer comprising an annular portion (30) placed inside said band (12) and carrying said fixing fingers (40, 40').

5. The assembly according to claim 1, wherein: The ribs (42, 42') are formed on pins cut out in the fixing fingers (40, 40') and are radially deformed.

6. The assembly according to claim 1, wherein: The fixing protrusion (62, 72) is formed on the transverse blade (60, 70), the transverse blade has a fastening portion (60A, 70A) and the fixing protrusion (62, 72), which is fastened to the first tube by the fastening portion, and the fixing protrusion (62, 72) is radially straightened relative to the fastening portion.

7. The assembly according to claim 6, wherein: The transverse blade has two said fixing protrusions (62, 72), and the collar carries two fixing fingers (40, 40') configured to cooperate with the fixing protrusions (62, 72).

8. The assembly of claim 1, wherein: The fixing projections (62, 72) are configured to define an angular wedging of the clamping system relative to the first tube (2).

9. The assembly according to claim 6, wherein: The blade (70) has two shoulders (70C) forming radial stops for fixing fingers (40, 40') carried by the collar and configured to cooperate with the fixing projections (72) and the shoulders (70C).

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