Seal locking assembly

Abstract

A sealing and locking assembly comprising: a sleeve end (4) of a first pipe element, a socket end (8) of a second pipe element, and a composite sealing gasket (12) for the sealing and locking assembly, the composite sealing gasket being between the sleeve end (4) and the socket end (8), the socket end comprising an anchoring groove (32) defined by a bottom surface (44) and a front surface (40), the composite sealing gasket comprising: a ring made of an elastic material, the ring extending along a central axis (X-X), having a gasket body (64) and an anchoring root (66), and at least one locking insert (62), the at least one locking insert being used to lock the joint between the sleeve end (4) and the socket end (8), the locking insert being at least partially embedded in the gasket body (64), the locking insert comprising: a radially outer head portion, the radially outer head portion being at least partially embedded in the gasket body The body (64) extends into the anchor groove (32) of the socket end, and a radially inner foot, the radially inner foot is designed to abut the sleeve end and includes at least a first engaging tooth (82, 84, 86), the first engaging tooth is suitable for clamping the outer surface (20) of the sleeve end (4), the head includes a radial protrusion, the assembly is characterized in that the anchor groove (32) is defined by an inclined surface, the inclined surface and the front surface (40) together form a connecting recess and an angle less than 180°, the head includes a stop tooth, the stop tooth is designed to abut against the connecting recess when the foot clamps the outer surface of the sleeve end, and the stop tooth and the radial protrusion are arranged so that, for any diameter of the bottom surface (44) of the socket end and the outer surface (20) of the sleeve end within the manufacturing tolerance range, and in a meridian cross-sectional view, the stop tooth of the locking insert (62) is adjacent in the connecting recess.

Description

Technical Field

[0001] The present invention relates to a locking insert for locking a joint between a sleeve end and a socket end,

[0002] The socket end includes an anchoring groove defined by an inclined surface and a front surface, a connecting recess is formed between the inclined surface and the front surface, and an angle less than 180° is formed between the inclined surface and the front surface.

[0003] Locking inserts include:

[0004] -head, and

[0005] - a foot comprising at least a first engaging tooth adapted to grip the outer surface of the sleeve end,

[0006] The head includes radial protrusions.

[0007] Locking inserts are particularly suitable for sealing and locking the connection of two cast iron pipes. Background Art

[0008] EP-A-526 373 describes a composite gasket comprising a sealing body and an anchoring bead of elastomeric material and a plurality of locking inserts of rigid material embedded in the anchoring bead.

[0009] The inclination of each locking insert during its eccentric movement between the sleeve end and the socket end is a function of the clearance between the outer diameter of the sleeve end and the inner diameter of the socket end. The gripping of the insert on the sleeve end causes a reaction force whose inclination angle in the median direction varies according to the clearance existing between the assembled sleeve ends.

[0010] The greater the reaction angle, measured relative to the radial direction, the greater the resistance of the locking element to the internal pressure of the fluid flowing through the assembly. On the other hand, the lower the reaction angle, the better the grip of the insert on the outer surface of the sleeve end. In fact, if the reaction angle is too large, the teeth of the insert may not grip the sleeve end when pressed and may slip over it, resulting in a poor lock.

[0011] The risk of having poor resistance under pressure is critical for the maximum clearance where the reaction angle is naturally low, while the risk of poor clamping of the insert is critical for the minimum clearance where the reaction angle is naturally high.

[0012] Therefore, the position of the locking insert relative to the sleeve end and the socket end must be determined by the manufacturing tolerances between the anchor grooves of the sleeve end and the socket end to achieve any permissible clearance. However, within the permissible tolerance range, and in particular towards the maximum clearance, the locking inserts of EP-A-526 373 occupy a position such that the reaction force angle relative to the radial direction when the pipe is subjected to the pressure of the fluid being conveyed is relatively low, which necessitates the use of a large number of inserts in order to reduce the locking force on each insert used individually, thereby avoiding puncture of the sleeve end at the highest permissible pressure.

[0013] A locking insert is also known from FR 2 966 554 or WO 201256163, which however presents a relatively low reaction angle relative to the radial direction, particularly towards the maximum gap, which also requires a large number of locking inserts to avoid the risk of piercing the sleeve end at the highest pressures.

[0014] Furthermore, for a given pipe thickness, the performance of the locking tubular joint depends on the number of inserts and the angle of entry of the inserts on the pipe wall at the end of the sleeve, in other words, the angle of inclination in the median direction: the greater the entry angle, the greater the punching or piercing force, and the greater the number of inserts must be in order to achieve the desired pressure resistance.

[0015] For example, for cast iron pipes with a nominal diameter of DN200 and pressure class C40 according to EN 545, it is necessary to use a composite sealing gasket equipped with 18 inserts according to the description in FR 2 966 554 to achieve the required properties, in particular with regard to pressure resistance. Summary of the Invention

[0016] One object of the present invention is therefore to design a locking insert and a corresponding tubular joint which enable good gripping of the insert on the sleeve end and good pressure resistance of the locking joint while achieving economy of manufacture.

[0017] The cost of the seal is mainly proportional to the number of inserts.The object of the present invention is therefore a locking insert which enables an adequate clamping between the sleeve end and the socket end with a reduced number of locking inserts.

[0018] To this end, the locking insert according to the invention enables relatively small entry angles.

[0019] Another object of the invention is to optimize the compromise between the reliability of the clamping of the insert on the end of the sleeve and the resistance to pressure of the locking.

[0020] To this end, the invention relates to a locking insert as described above, characterized in that the head comprises a retaining tooth adapted to be applied to the connection recess when the foot grips the outer surface of the sleeve end.

[0021] According to certain embodiments, the locking insert includes one or more of the following features:

[0022] - in side view, the opening angle of the locking tooth is between 35° and 55°, in particular between 40° and 50°, preferably between 42° and 47°;

[0023] - the radius of curvature of the stop tooth is less than 1 mm, preferably less than 0.5 mm;

[0024] - in a side view, the stop tooth, the first engaging tooth and the radial protrusion form an engagement angle between the stop tooth, the first engaging tooth and the radial protrusion, the engagement angle being between 30° and 50°, preferably between 35° and 45°;

[0025] - in side view, the first engaging tooth, the stopping tooth and the radial protrusion form an abutment angle between the first engaging tooth, the stopping tooth and the radial protrusion, the abutment angle being between 55° and 70°, and preferably between 60° and 70°;

[0026] - in side view, the retaining tooth and the first engaging tooth are connected by a convex or rectilinear profile, in particular by a profile comprising or consisting of two straight lines; and

[0027] - According to the side view, the retaining tooth and the radial projection are connected by a concave or rectilinear profile, in particular by a concave profile comprising a single concave portion.

[0028] The present invention is also directed to a composite sealing gasket for use in a sealing and locking assembly between a sleeve end of a first pipe element and a socket end of a second pipe element, the composite sealing gasket comprising

[0029] - a ring of elastic material extending according to a central axis, having a washer body and an anchoring bead, and

[0030] - at least one locking insert at least partially embedded in the washer body,

[0031] Characterized in that each locking insert is an insert as described above, the head being a radially outer head at least partially embedded in the body of the washer and intended to extend into the anchoring groove of the end of the socket, and the foot being a radially inner foot intended to press against the end of the sleeve.

[0032] According to a particular embodiment, the seal comprises one or more of the following features: - the anchoring bead is made of a material with a harderness greater than the hardness of the gasket material.

[0033] The present invention also features a sealing and locking assembly comprising a sleeve end portion of a first pipe member, a socket end portion of a second pipe member, and a gasket, the gasket being a composite gasket as described above.

[0034] According to certain embodiments, the assembly includes one or more of the following features:

[0035] the socket end comprises an anchoring groove delimited by a bottom surface, an inclined surface and a front surface, the bottom surface in particular extending coaxially with respect to the central axis,

[0036] The inclined surface and the front surface form a connecting recess therebetween and form an angle less than 180°, and

[0037] the retaining teeth and the radial projections are arranged in such a way that for any diameter of the bottom surface of the socket end and the outer surface of the sleeve end within the manufacturing tolerance range and in a meridian cross-sectional view, the retaining teeth of the locking insert are supported in the connecting recess;

[0038] - the curvature radius of the connecting recess is about 1 mm, preferably less than 0.5 mm;

[0039] - the radius of curvature of the stop tooth is smaller than the radius of curvature of the connecting recess;

[0040] - a front surface formed by an inlet collar at the end of the socket, the front surface extending at an angle of at least 80° relative to the central axis;

[0041] an inclined surface is arranged axially and radially between the bottom surface and the front surface, the inclined surface having an inclination of between 30° and 60° relative to the central axis; and

[0042] - For any diameter of the bottom surface and the outer surface within the manufacturing tolerance range, the reaction angle (ε) measured between the line acting as support for the reaction force clamping the insert on the end of the sleeve and the plane perpendicular to the central axis is between 20° and 45°. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The invention will be better understood from the following description given by way of example only and made with reference to the accompanying drawings, in which:

[0044] [ Figure 1 ] Figure 1 is a half view in meridian section of an assembly of two pipes and a composite gasket inserted between them, before manufacturing the locking assembly according to the invention;

[0045] [ Figure 2 ] Figure 2is a meridian cross-sectional view of a gasket according to the present invention;

[0046] [ Figure 3 ] Figure 3 is a meridian cross-sectional view of a portion of an assembly according to the present invention, wherein the socket end and the sleeve end define a minimum gap therebetween,

[0047] [ Figure 4 ] Figure 4 is a meridian cross-sectional view of a portion of an assembly according to the invention, wherein the socket end and the sleeve end define a maximum gap therebetween,

[0048] [ Figure 5 ] Figure 5 is a meridian cross-sectional view of a portion of an assembly according to the present invention, the socket end and the sleeve end defining an intermediate gap therebetween, and

[0049] [ Figure 6 ] Figure 6 is a meridian cross-sectional view of a portion of an assembly according to the present invention showing the socket end and the cannula end when the cannula end is inserted into the socket end. DETAILED DESCRIPTION

[0050] Figure 1 A sealing and locking assembly according to the invention is shown and designated generally by the reference numeral 2 .

[0051] The assembly 2 includes a sleeve end 4 or male end integral with a first pipe 6 , a socket end 8 or female end integral with a second pipe 10 , and a composite gasket 12 .

[0052] The assembly 2 extends along a central axis XX. Hereinafter, the terms "radially," "axially," "circumferentially," and "meridian" will be used relative to this axis. The term "proximal" refers to a position axially close to the inlet of the socket end, and the term "distal" refers to a position axially away from the inlet and toward the interior of the socket end (see below).

[0053] This assembly defines a direction I in which the sleeve end 4 is inserted into the socket end 8 .

[0054] The sleeve end 4 comprises a cylindrical outer surface 20 of diameter d having an inlet chamfer 22. The sleeve end 4 is manufactured with a diameter tolerance such that the actual diameter d may be between a maximum outer diameter d and a maximum outer diameter d. 最大 and minimum outer diameter d 最小 Diameter d 最大 and diameter d 最小 exist Figure 1 Shown as mixed lines.

[0055] The socket end 8 comprises, axially continuously from the socket end inlet to the bottom, an inlet collar 30 , an annular anchoring groove 32 , a stepped portion 34 and a receiving cavity 36 adapted to receive the sleeve end 4 in a non-constrained manner.

[0056] The inlet collar 30 defines an inlet surface 38 which is a cylindrical surface having a diameter of DISE (see Figure 3 ).

[0057] The annular anchor groove 32 is defined by an annular front surface 40 of the inlet collar 30 , an inclined surface 42 , a cylindrical bottom surface 44 having a circular cross section about the axis XX, and a front surface 46 of the stepped portion 34 .

[0058] The front surface 46 is oriented against the direction I toward the inlet collar 30 .

[0059] Typically, the front surface 40 extends at an angle of at least 80° relative to the central axis XX and has an axial component oriented in the direction I. Preferably, the front surface 40 makes an angle of at least 85° with the central axis XX. The front surface 40 extends from the inlet surface 38 to the inclined surface 42 .

[0060] The inclined surface 42 extends at an angle between 30° and 60° relative to the centre axis XX and has an axial component directed in the direction I. The inclined surface 42 is therefore arranged radially and axially between the bottom surface 44 and the front surface 40 .

[0061] Furthermore, the front surface 40 directly adjoins the inclined surface 42 , and these two surfaces 40 , 42 form a connecting recess 48 .

[0062] Inclined surface 42 is directly connected to bottom surface 44. In a meridian view, annular front surface 40 connects to inclined surface 42 at a connection point PR, forming a connection recess 48 at this location. This connection point PR is located at a distance DPRSE from inlet surface 38 that is between 10% and 90% of the difference between the diameter of inlet surface DISE and the diameter D of bottom surface 44. Preferably, distance DPRSE is between 40% and 60% of this difference, or between 45% and 55% of this difference.

[0063] In a meridian view, the radius of curvature of the connecting recess 48 is approximately 1 mm, preferably less than 0.5 mm.

[0064] In a meridian section, the angle γ between the front surface 40 and the inclined surface 42 is less than 180°, in particular between 110° and 160°. The inclination angle of the inclined surface 42 relative to the axis XX is, for example, between 30° and 60°.

[0065] like Figure 5As shown, the bottom surface 44 is also limited by manufacturing tolerances so that its actual diameter D can be within the maximum diameter D 最大 and minimum diameter D 最小 Changes between.

[0066] Note that the maximum diameter d of the surface 20 最大 Smaller than the diameter DISE of the surface 38 .

[0067] The gasket 12 comprises, in a meridian section, an elastic ring 60 made of a flexible or elastic material (for example an elastomer), which extends along a central axis XX and in which a plurality of locking inserts 62 are embedded ( Figure 2 ).

[0068] The resilient ring 60 comprises a solid annular gasket body 64 which, in the locked state, extends from the tubular joint toward the bottom of the socket end, and an anchoring bead 66 which is located on the inlet side of the socket end and projects radially outward relative to the gasket body 64 .

[0069] The washer body 64 has a shape that opens toward the distal side from the anchoring bead 66 side in the axial direction XX. Therefore, in a meridian cross section, the washer body 64 is generally V-shaped, opening toward the distal side.

[0070] The anchoring bead 66 has a shape complementary to the shape of the anchoring groove 32 or at least the surfaces 42, 44 and 46 and in the installed state rests completely on the inclined surface 42, the bottom surface 44 and the front surface 46. The anchoring groove thus serves as a receiving portion for the anchoring bead 66 of the washer.

[0071] The washer body 64 has a front surface 68 which, in the installed state, abuts the annular front surface 40 .

[0072] The anchoring bead 66 is made of a material with a greater hardness than the material of the washer body 64 .

[0073] The anchoring bead 66 and the washer body 64 are separated from one another by an interface region 70 which, in this case, is generally cylindrical having an axis XX.

[0074] The washer body 64 is made of an elastomer with a Shore A hardness between 50° Shore and 70° Shore, preferably about 60° Shore A. The anchoring bead 66 is made of an elastomer with a Shore A hardness between 70° Shore and 90° Shore, preferably about 80° Shore A.

[0075] The locking inserts 62 are evenly distributed over the entire circumference of the elastic ring 60 , and each locking insert 62 is made of a high-hardness material, such as a hard metal alloy or ceramic.

[0076] In a meridian view, each locking insert 62 comprises a radially outer head 72 and a radially inner foot 74. The head 72 extends generally radially relative to the axis XX, while the foot 74 is inclined relative to this axis so that the feet converge towards the axis XX. Thus, the locking insert 62 presents an angled profile.

[0077] Each locking insert 62 is partially embedded in the washer body 64 and is partially covered by the resilient material of the washer body.

[0078] More specifically, Figure 2 As shown in FIG, the head 72 comprises, on its radially outer head and proximal side, a profile forming a retaining tooth 76 adapted to be pressed into the connecting recess 48 when the foot 74 engages the outer surface 20 of the sleeve end.

[0079] Distally, the head 72 also comprises a radial projection 78 provided with a retaining nose 80 oriented axially in the insertion direction I and adapted to be inserted into the socket end ( Figure 6 ) is pressed against the front surface 46 via the anchoring bead 66, thereby preventing the insert from being ejected from the anchoring groove 32 to the interior of the socket end. For this purpose, the radial protrusion 78 partially extends into the anchoring bead.

[0080] Furthermore, the foot 74 includes three engaging teeth at its radially inner end, namely a first engaging tooth 82, a second engaging tooth 84, and a third engaging tooth 86, which are axially offset from one another. These three engaging teeth are adapted to grip the outer surface 20 of the sleeve end 4 (see below) and, when the washer is in the resting state, extend beyond the elastic ring 60. In a meridian view, the engaging teeth 82, 84, 86 extend in a convex curve. Furthermore, the foot 74 includes an engaging stop 88, which is embedded in the washer body, at the distal end and has the function of limiting the insertion of the insert into the sleeve end so as not to damage it. In a meridian view, the engaging stop 88 has a circular profile relative to the profiles of the engaging teeth 82, 84, 86.

[0081] From the meridian section ( Figure 2 ) it can be seen that the opening angle (α) of the locking tooth 76 is between 35° and 55°, in particular between 40° and 50°, preferably between 42° and 47°.

[0082] As can be seen in the meridian section, the radius of curvature of the stop tooth 76 is less than 1 mm, preferably less than 0.5 mm. Therefore, the stop tooth preferably has a sharp edge.

[0083] The radius of curvature of the locking tooth 76 is smaller than the radius of curvature of the connecting recess 48 .

[0084] The stop tooth 76 and the connecting recess 48 have such a profile that the stop tooth 76 presses only at one point on the connecting recess 48 or the socket end when viewed from the side.

[0085] As can be seen from the meridian cross section, the stop tooth 76, the first engaging tooth 82, and the radial protrusion 78 form an engagement angle β. This engagement angle is the angle between two lines, one extending between the first engaging tooth 82 and the stop tooth 76, and the other extending between the first engaging tooth 82 and the radial protrusion 78.

[0086] The engagement angle β is between 30° and 50°, preferably between 35° and 45°.

[0087] When viewed in a meridian cross-section, the first engaging tooth 82, the stop tooth 76, and the radial protrusion 78 form an adjacency angle δ with one another. The adjacency angle δ is the angle between two lines, one extending between the stop tooth 76 and the radial protrusion 78, and the other extending between the stop tooth 76 and the first engaging tooth 82. The adjacency angle is between 55° and 70°, preferably between 60° and 70°.

[0088] The head 72 includes a front protrusion 90 radially offset from the stop tooth 76 toward the central axis XX. From a side view, the stop tooth 76 and the first engaging tooth 82 are connected by a convex profile forming the front protrusion 90. In particular, the profile includes or consists of two straight lines. Alternatively, the profile can be straight.

[0089] The stop tooth 76 and the radial projection 78 are connected in meridian section by a concave profile, in this case by a concave profile having a single concave portion. Alternatively, the profile is straight.

[0090] The stop tooth 76 may be slightly embedded in the washer. The transition area 70 may be located at the stop tooth 76.

[0091] For any gap between the outer surface 20 and the bottom surface 44 within the allowed manufacturing tolerances, the locking insert 62 with the retaining teeth 76 fits into the connecting recess 48 of the socket end, particularly when the pipe is subject to the internal pressure of the fluid carried by the pipe.

[0092] More specifically, when the gap between the surfaces 20 and 44 is within the minimum gap J1 ( Figure 3 ) and the intermediate gap, the locking insert 62 is pressed into the connecting recess 48, and the first engaging teeth 82 and / or the second engaging teeth 84 clamp the surface 20.

[0093] When the gap between the surfaces 20 and 44 is between the intermediate gap and the maximum gap J2 ( Figure 4), the locking insert 62 is pressed into the connecting recess 48 , and the second engaging teeth 84 and / or the third engaging teeth 86 clamp the surface 20 .

[0094] Regardless of the clearance between the outer surface 20 and the bottom surface 44, provided that the clearance is within the permitted manufacturing tolerances, the reaction angle ε, in meridian view, varies very little and is always between 20° and 45°. This reaction angle is measured between a plane perpendicular to the axis XX and a line serving as a support for the reaction forces of the insert, connecting the point of application of the stop tooth 76 on the socket end to the point of application of the engaging tooth on the sleeve end, or, in the case of multiple teeth, connecting the point of application of the stop tooth on the socket end to the midpoint of application of the engaging tooth on the sleeve end.

[0095] The reaction angles are generally referred to as ε, and in the embodiment shown in the figures are referred to as ε1, ε2 and ε3.

[0096] The assembly according to the invention is carried out as follows.

[0097] First, the composite sealing gasket 12 is inserted into the socket end 8, the gasket body 64 is pressed against the step portion 34, and the anchoring bead 66 is fitted into the annular anchoring groove 32, so that the axis of the composite sealing gasket coincides with the axis of the socket end.

[0098] Then, the sleeve end 4 is inserted through the composite sealing gasket 12 in direction I until the chamfer 22 of the sleeve end approaches the bottom of the cavity 36. During the insertion of the sleeve end, as shown in FIG. Figure 6 As shown, the retaining nose 80 of the radial projection 78 locks onto the front surface 46 of the stepped portion 34, thereby preventing the insert from being ejected from the anchoring groove 32 toward the interior of the socket end. In addition, during insertion into the cannula end, the anchoring bead 66 exerts a force on the radial projection 78 that tends to urge the insert radially inward and retain the insert against the cannula end, thereby facilitating clamping of the insert to the cannula end when pressurized.

[0099] The anchor bead 66, which is made of an elastomeric material that is harder than the main body 64, has the following broader function, namely, when the end of the sleeve is inserted into the end of the socket, the anchor bead prevents the composite sealing gasket 12 from being discharged from the anchor groove 32, while the main body 64, which is made of a softer elastomeric material, is more easily deformed, which facilitates the insertion of the sleeve end.

[0100] Then, upon application of pressure, the sleeve end 4 is pulled back axially, causing the locking insert 62 to retract. The locking insert 62 changes its inclination relative to the axis XX through an angular deflection that is opposite and smaller than the previous one. During this reversal, the retaining tooth 76 presses against the socket end at the connection recess 48, and at least one of the teeth 82, 84, 86 grips the outer surface of the sleeve end 4. The over-center movement of the insert between these two supports provides considerable resistance to the continued axial withdrawal movement of the sleeve end 4. This achieves locking of the assembly.

[0101] The anchor bead 66 , made of a relatively hard elastomeric material, exerts a force on the stop tooth 76 that prevents the stop tooth 76 from being displaced by sliding along the inclined surface 42 , thereby ensuring that the stop tooth 76 is positioned and retained in the connecting recess 48 of the anchor groove during pressurization.

[0102] Furthermore, when pressurized, the radial projections 78 of the locking insert do not contact the bottom surface 44. The portion of the anchor bead that extends between the radial projections 78 and the bottom surface 44 then acts as a return spring by exerting a radially inward force on the radial projections 78, which forces the teeth into engagement with the sleeve end and, once pressure is established, keeps the insert pressed against the sleeve end. This force is even greater when the anchor bead is made of a hard elastomeric material, thereby facilitating the insertion of the engaging teeth into the sleeve end and holding them in place.

[0103] In addition, refer to Figure 3 and Figure 4 The operation of the composite sealing gasket 12 according to the present invention will be described as follows: d and D In these figures, the elastic ring 60 is omitted for clarity.

[0104] During assembly of the pipes 6 and 10, after the aforementioned angular deflection of the inserts, each locking insert is in a position according to the diameter d and D The gap that exists between them varies with the tilt position.

[0105] Figure 3 The position of the locking insert 62 is shown when the sleeve end 4 is clamped under pressure, with the gap between the pipes being the minimum gap J1. To this end, the socket end 8 comprises an anchoring groove 32 having a diameter of D Corresponding to the minimum diameter D 最小 , while the sleeve end 4 has an outer diameter d corresponding to the maximum diameter d 最大 Therefore, the two diameters D 最小 and d 最大 A minimum gap J1 between the two surfaces is defined.

[0106] It can be seen that when the cannula end 4 is gripped, and in a meridian view, the locking insert 62 presses against the socket end at a single point, namely the retaining tooth 76 in the connecting recess 48. Furthermore, only the engaging tooth closest to the entrance to the socket end, namely the first engaging tooth 82, grips the outer surface 20 of the cannula end.

[0107] The locking insert 62 is inclined at a reaction angle, which is defined as follows. The locking insert 62 presses against the connection recess 48 at a point P that coincides with the connection point PR. The point of application of the engaging tooth 82 on the surface 20 of the sleeve end 4, together with the point P, defines a line L that serves as a support for the reaction force of the locking insert 62. The angle ε1 measured between this line L and a plane perpendicular to the axis XX is referred to as the "reaction angle" of the clamping.

[0108] Figure 4 Shows something like Figure 3 , but with the following differences.

[0109] The anchor groove 32 has a maximum diameter corresponding to D 最大 The outer surface 20 of the sleeve end has a minimum diameter d 最小 , so that a gap J2 greater than the gap J1 is defined between the two surfaces. The gap J2 is the maximum gap allowed by the manufacturing tolerances of the sleeve end 4 and the socket end 8.

[0110] It can be seen that when gripping the sleeve end 4, the locking insert 62 also grips the socket end at a single point, namely the stop tooth 76 in the connecting recess 48. Furthermore, only the engagement tooth furthest from the socket end entrance, namely the third engagement tooth 86, grips the outer surface of the sleeve end.

[0111] The resulting clamping reaction angle ε2 is measured between the radial direction and the line L passing through the Figure 3 The points of the assembly in the embodiment are substantially the same as point P and pass through the contact point between the outer surface of the sleeve end and the third tooth 86. This angle ε2 is substantially the same as the angle ε1, so the clamping characteristics are the same as Figure 3 The situation is similar in .

[0112] Figure 5 A meridian cross-section of a portion of an assembly according to the invention is shown, wherein the socket end and the cannula end define an average gap J3 between them. It can be seen that when the cannula end 4 is clamped, the locking insert 62 also presses against the socket end at a single point, namely, the stop tooth 76 in the connecting recess 48. In addition, the two proximal engagement teeth 82, 84 press against the outer surface of the cannula end.

[0113] The resulting clamping reaction angle ε3 is measured between the radial direction and the line L passing through the Figure 3 and Figure 4 The points of the assembly in FIG. 8 are substantially the same as point P and pass through a point on the outer surface of the sleeve end approximately midway between the two engaging teeth 82 , 84 .

[0114] It can also be seen that in this case the reaction angle ε3 is substantially the same as the angle ε1 and the angle ε2.

[0115] Figure 6 is a meridian cross-sectional view of a portion of an assembly according to the present invention, with the socket end and the sleeve end shown with the sleeve end inserted into the socket end. The shape of the locking insert 62 and the relatively stiff, resilient anchor bead portion extending between the radial projection 78 and the bottom surface 44 prevent excessive counterclockwise tilting in the figure and thus ensure proper positioning of the retaining tooth 76 during pressurization of the tubular joint.

[0116] According to the invention, the contact of the locking insert 62 with the connecting recess 48 via the retaining teeth 76 enables effective clamping. Therefore, the number of locking inserts for a given clamping force can be small, thereby reducing the manufacturing costs of the composite sealing gasket.

[0117] For all permitted clearances between the surfaces 20 and 44 , the locking insert 20 presses against the connecting recess 48 according to a single point contact in meridian view.

[0118] Therefore, for a given locking force, the manufacturing tolerances of the insert surface, the sleeve end surface and the socket end surface can be large, while the number of locking inserts can be small. Therefore, the tubular joint and the composite sealing gasket according to the present invention are economical.

Claims

1. A sealing and locking assembly, comprising: - a sleeve end portion (4) of a first pipe member, - a socket end (8) of the second conduit member, and - a composite sealing gasket (12) for said sealing and locking assembly, said composite sealing gasket being between said sleeve end (4) and said socket end (8), The socket end includes an anchoring groove (32) defined by a bottom surface (44) and a front surface (40), and The composite sealing gasket comprises: a ring (60) of elastic material extending according to a central axis (XX) and having a washer body (64) and an anchoring bead (66), and at least one locking insert (62) for locking the joint between the sleeve end (4) and the socket end (8) and at least partially embedded in the gasket body (64), The locking insert comprises: a radially outer head (72) at least partially embedded in the washer body (64) and extending into the anchor groove (32) at the end of the socket, and a radially inner foot (74) intended to bear against the sleeve end and comprising at least a first engaging tooth adapted to grip the outer surface (20) of the sleeve end (4), and The radially outer head portion (72) includes a radial protrusion (78), It is characterized in that The anchoring groove (32) is defined by an inclined surface (42), the inclined surface (42) and the front surface (40) forming a connecting recess (48) therebetween and forming an angle (γ) less than 180°, The radially outer head portion (72) includes a retaining tooth (76) adapted to be pressed into the connecting recess when the radially inner foot portion grips the outer surface of the sleeve end portion, and The retaining teeth (76) and the radial protrusions (78) are arranged so that, for any diameter of the bottom surface (44) of the socket end and the outer surface (20) of the sleeve end within manufacturing tolerances and in a meridian cross-sectional view, the retaining teeth (76) of the locking insert (62) are supported in the connecting recess.

2. The assembly according to claim 1, wherein The opening angle (α) of the locking tooth (76) is between 35° and 55°.

3. The assembly according to claim 2, wherein The opening angle (α) is between 40° and 50°.

4. The assembly according to claim 3, wherein The opening angle (α) is between 42° and 47°.

5. The assembly according to claim 1 or 2, wherein The curvature radius of the stopping tooth (76) is less than 1 mm.

6. The assembly according to claim 5, wherein The curvature radius of the stopping tooth (76) is less than 0.5 mm.

7. The assembly according to claim 1 or 2, wherein: The stop tooth (76), the first engaging tooth and the radial protrusion (78) form an engaging angle (β) therebetween, and the engaging angle is between 30° and 50°.

8. The assembly according to claim 7, wherein The engagement angle (β) is between 35° and 45°.

9. The assembly according to claim 1 or 2, wherein: The first engaging tooth, the stopping tooth (76) and the radial protrusion (78) form an abutment angle (δ) therebetween, and the abutment angle is between 55° and 70°.

10. The assembly according to claim 9, wherein The adjacency angle (δ) is between 60° and 70°.

11. The assembly according to claim 1 or 2, wherein The stop tooth (76) and the first engaging tooth are connected by a convex or linear profile.

12. The assembly according to claim 11, wherein The profile connecting the stop tooth (76) and the first engaging tooth is a profile including or consisting of two straight lines.

13. The assembly according to claim 1 or 2, wherein The stop tooth (76) and the radial projection (78) are connected by a concave or straight profile.

14. The assembly according to claim 13, wherein The profile connecting the stop tooth and the radial projection is a concave profile having a single concave portion.

15. The assembly according to claim 1 or 2, wherein The anchoring bead (66) is made of a material having a harder hardness than the material of the washer body (64).

16. The assembly according to claim 1 or 2, wherein The bottom surface (44) extends coaxially with respect to the central axis (XX).

17. The assembly according to claim 1 or 2, wherein The curvature radius of the connecting recess is approximately 1 mm, or less than 0.5 mm.

18. The assembly according to claim 1 or 2, wherein The curvature radius of the locking tooth (76) is smaller than the curvature radius of the connecting recess (48).

19. The assembly according to claim 1 or 2, wherein The front surface (40) is formed by the inlet collar (30) of the socket end (8), the front surface extending at an angle of at least 80° relative to the central axis (XX).

20. The assembly of claim 1 or 2, wherein: The inclined surface (42) is arranged axially and radially between the bottom surface (44) and the front surface (40), and has an inclination of between 30° and 60° relative to the central axis (XX).

21. The assembly according to claim 1 or 2, wherein For any diameter of the bottom surface (44) and the outer surface (20) within manufacturing tolerances, the reaction angle (ε) measured between a line acting as a support for the reaction force clamping the locking insert on the end of the sleeve and a plane perpendicular to the central axis (XX) is between 20° and 45°.

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