Tubular joint comprising a sealing gasket with locking inserts fixed by complementary shape

Abstract

Tubular joint comprising a sealing gasket with locking inserts fixed by complementary shape. Tubular joint (10) comprising: - a push-fit end (12) defining a central axis (X) and a housing (14), - a plain end (16) adapted for insertion into the housing, - a sealing gasket (18) comprising a sealing body (38) made of elastic material, and locking inserts (36) distributed angularly around the axis. Each insert comprises a head (42), and a body (44) extending obliquely with respect to the axis between the head and the plain end and forming one or more teeth to bite into the plain end, each insert being adapted to brace itself between a groove (24) and the plain end to prevent disengagement of the plain end.The inserts are at least partially overmolded by the sealing body and have a recess or protrusion adapted to fix each insert to the sealing body by complementary shape. Figure for the abbreviation: Figure 1.

Description

Title of the invention: Tubular joint comprising a sealing gasket with locking inserts fixed by complementary shape. Field of the invention

[0001] The present invention relates to a tubular junction comprising:

[0002] - a push-fit end defining a central axis and a housing,

[0003] - a plain end adapted to be inserted into the housing along the central axis for to reach a position that is fitted relative to the end to be fitted, and

[0004] - a sealing gasket located radially with respect to the central axis between the plain end and the interlocking end when the plain end is in the interlocking position.

[0005] Such a junction is, for example, suitable for connecting two tubular elements of a drinking water, industrial water, or wastewater pipeline. The tubular elements are, for example, pipes to be joined or a pipe and a fitting to be joined. State of the art

[0006] The sealing gasket generally comprises a sealing body made of elastic material, for example elastomer material, arranged around the central axis.

[0007] To prevent the plain end from dislodging, it is known to use a plurality of metal locking inserts distributed angularly around the central axis, between the plain end and the push-fit end, and defining teeth adapted to bite into the plain end. The metal locking inserts are advantageously fixed to the sealing body using an adhesive, which allows the sealing body and the locking inserts to be easily positioned in the housing before push-fitting, without the locking inserts detaching. The adhesive acts as a kind of glue between the metal locking inserts and the elastic material. The adhesive is not necessarily compatible with potable water.

[0008] However, the locking inserts are often manufactured in one location, for example in a foundry, while the adhesive is produced in another location, for example in a chemical plant, and the adhesive is applied to the locking inserts in yet another location. The bonded inserts are then overmolded with the elastic material in yet another location, for example in an elastomer manufacturing plant. The assembled sealing gaskets, with their locking inserts, are then shipped to the foundry that manufactures the pipe components to be assembled, so as to gather all the necessary elements to complete the pipe joint.

[0009] This type of tubular joint is entirely satisfactory in terms of performance and ease of implementation. However, its production is complex from a logistical point of view, with the inserts and the adhesive product being shipped from their industrial production sites to a site where the adhesive is applied to the inserts, then the bonded inserts are shipped to the sealing gasket production site, and finally the sealing gaskets fitted with locking inserts are shipped to the tubular element manufacturing site.

[0010] Furthermore, sealing gaskets are generally recycled, particularly to recover the locking inserts, which are relatively expensive parts, and to process the elastic material. However, these recycling operations are also complex due to the adhesive present on the inserts.

[0011] An object of the invention is to provide an efficient tubular joint, at a competitive cost, which is easy to implement and whose production and / or recycling are also facilitated. Summary of the invention

[0012] To this end, the invention relates to a tubular junction comprising:

[0013] - a push-fit end defining a central axis and a housing,

[0014] - a plain end adapted to be inserted into the housing along the central axis for to reach a position that is fitted relative to the end to be fitted, and

[0015] - a sealing gasket located radially with respect to the central axis between the plain end and the push-fit end when the plain end is in the push-fit position,

[0016] the sealing gasket comprising:

[0017] - a sealing body made of elastic material extending around the central axis and being at least partially situated in an annular groove defined by the socket end, the sealing body comprising a radially compressed portion between the plain end and the socket end when the plain end is in the socketed position, and

[0018] - a plurality of locking inserts distributed angularly around the central axis,

[0019] each of the locking inserts comprising:

[0020] - a head located in the throat, and

[0021] - a body extending obliquely with respect to the central axis between the head and the end plain and having a radially inward end, on the side opposite the head, forming one or more teeth adapted to bite into the plain end, each of the locking inserts being adapted to brace between the groove and the plain end to prevent disengagement of the plain end from the socket end,

[0022] each of the locking inserts being at least partially overmolded by the sealing body, and defining at least one recess or comprising at least one protrusion, hollow or protrusion being adapted to fix each of the locking inserts on the sealing body by complementary shape.

[0023] According to other advantageous aspects of the invention, the tubular junction comprises one or more of the following features, taken individually or in all technically possible combinations:

[0024] - the sealing gasket is devoid of an adhesive layer applied to each of the locking inserts;

[0025] - each of the locking inserts is fixed to the sealing body only by complementarity of form;

[0026] - each of the locking inserts defines at least two through-holes extending circumferentially around the central axis and filled by the sealing body;

[0027] - each of the locking inserts defines at least four blind holes extending in the circumferential direction, two of the four blind holes being defined by a first surface of each of the locking inserts, and two other of the four blind holes being defined by a second surface of each of the locking inserts, the second surface being opposite the first surface in the circumferential direction, two of the four blind holes being respectively opposite two other of the four blind holes in the circumferential direction, the four blind holes being filled by the sealing body;

[0028] - each of the locking inserts defines at least four protrusions extending in the circumferential direction, two of the four protrusions being defined by a first surface of each of the locking inserts, and two other of the four protrusions being defined by a second surface of each of the locking inserts, the second surface being opposite the first surface in the circumferential direction, two of the four protrusions being respectively opposite two other of the four protrusions in the circumferential direction, the four protrusions sinking into the sealing body;

[0029] - the body of each of the locking inserts comprises a radially exterior, said surface defining either of a rail or a "T" groove, the rail or groove extending in the circumferential direction, the sealing body filling the groove or overmolding the rail;

[0030] - each of the locking inserts defines at least one through-hole extending in a radial plane with respect to the central axis;

[0031] - the through housing extends between two surfaces of the body of each of the inserts of locking, the two surfaces being radially opposed to each other; and

[0032] - the through housing opens onto a radially external surface defined by the head of each of the locking inserts, said surface being opposite a bottom of the groove. Figures

[0033] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings, in which:

[0034] [Fig-1] [Fig.1] is a schematic view, in cross-section along a radial plane, of a tubular junction according to the invention

[0035] [Fig.2] [Fig.2] is a perspective view of a locking insert shown in [Fig.1], and

[0036] [Fig.3] [Fig.4] [Fig.5] [Fig.6] [Fig.7] [Fig.8] Figures 3 to 8 are perspective views of locking inserts, respectively according to a first variant, a second variant, a third variant, a fourth variant, a fifth variant and a sixth variant of the locking insert shown in Figures 1 and 2. Tubular junction

[0037] With reference to [Fig.1], a tubular junction 10 according to the invention is described.

[0038] The tubular junction 10 includes a push-fit end 12 defining an axis The tubular joint 10 comprises a central X and a housing 14, and a plain end 16 adapted to be inserted into the housing along the central X axis to achieve a spigot position relative to the spigot end. The tubular joint 10 includes a sealing gasket 18 located radially with respect to the central X axis between the plain end 16 and the spigot end 12 when the plain end is in the spigot position. The tubular joint 10 is, for example, buried in soil 20.

[0039] The plain end 16 is part of an element 16A such as a pipe, and the socket end 12 is part of an element 12A such as a pipe or fitting. The elements 16A and 12A are themselves part of a pipeline 22 or a pipeline system (not shown), and are suitable, for example, for conveying or storing drinking water, industrial water, or wastewater. The plain end 16 and the socket end 12 are advantageously made of cast iron.

[0040] The nested position is visible in [Fig.1].

[0041] A non-inserted position, in which the plain end 16 is away from the interlocking end 12, is not shown but can easily be deduced from the inserted position by shifting the plain end to the left relative to the interlocking end on [Fig.1],

[0042] The socket end 12 defines an annular groove 24 adapted to receive the sealing gasket 18.

[0043] In the example, the interlocking end 12 is in one piece.

[0044] According to one variant (not shown), the socket end 12 comprises several parts, for example a body and an end part (axially on the side of the plain end) fixed to the body in the fitted position, for example by means of fixing flanges, and receiving the plain end 16 in the fitted position.

[0045] The housing 14 is advantageously axisymmetric around the central axis X and for example defined by a flared part 26 of the end with a fitting 12.

[0046] The groove 24 opens radially into the housing 14. The groove is, for example, axially delimited by two surfaces 28, 30 axially opposed to each other. The groove 24 has, for example, two cylindrical ends 32, 34 around the central axis X.

[0047] In the example, the two surfaces 28, 30 diverge towards the central axis X, and form two angles a and [3 with the central axis X advantageously between 70° and 90°.

[0048] The bottom 32 is for example further from the central axis X than the bottom 34, and located on the side of the plain end 16 relative to the bottom 34. The bottom 32 is radially opposite a plurality of locking inserts 36 (only one of which is shown in [Fig.1]) of the sealing gasket 18. Sealing gasket

[0049] The sealing gasket 18 comprises a sealing body 38 made of an elastic material, extending around the central axis X and at least partially situated in the annular groove 24. Such a material is flexible or resilient. This material is sometimes described as "hyperelastic," that is, having high elasticity. Examples include synthetic or natural elastomers.

[0050] The sealing gasket 18 advantageously consists solely of the sealing body 38 and the plurality of locking inserts 36. In particular, the sealing gasket 18 advantageously lacks an adhesive layer that would be applied to each of the locking inserts 36 to fix them to the elastic material.

[0051] The sealing body 38 is for example in contact with the surface 28 and the two bottoms 32, 34 which partially delimit the groove 24.

[0052] The sealing body 38 is advantageously made of elastomeric material, for example NBR rubber (acrylonitrile butadiene rubber; in English: Nitrile Butadiene Rubber) or EPDM (Ethylene propylene diene monomer).

[0053] The sealing body 38 comprises a portion 40 that is radially compressed between the plain end 16 and the socket end 12 when the plain end is in the socketed position. In the example, the portion 40 in question is compressed between the base 34 and the plain end 16. Locking inserts

[0054] The locking inserts 36 are distributed angularly around the central axis X, advantageously regularly. Their number depends on the nominal diameter of the tubular elements to be assembled.

[0055] The locking inserts 36 are advantageously analogous to each other, so only one of them will be described below with reference to figures 1 and 2.

[0056] The locking insert 36 comprises a head 42 located in the groove 24, and a body 44 extending obliquely with respect to the central axis X between the head and the plain end 16. The locking insert 36 is advantageously delimited in the circumferential direction (around the central axis X) by a first surface 46 and a second surface 48 oriented radially or parallel to each other.

[0057] Each of the locking inserts 36 is adapted to brace itself between the groove 24 and the plain end 16 to prevent the plain end from dislodging from the socket end 12.

[0058] The locking inserts 36 are made of a material with a higher hardness than the material of the plain end and are preferably made of metal, for example stainless steel.

[0059] The locking insert 36 is at least partially overmolded by the sealing body 38, and defines at least one recess 50 adapted for fixing the locking insert 36 to the sealing body 38 by complementary shape. Complementary shape is advantageously the only means of fixing the locking insert 36 to the sealing body 38.

[0060] Possibly, the locking insert 36 forms a restriction 52 between the head 42 and the body 44, but which in the example is not sufficient to ensure a fixing by complementarity of form.

[0061] In the example shown in Figures 1 and 2, the locking insert 36 defines two through-holes 54A, 54B extending circumferentially around the central axis X, for example substantially perpendicular to the first surface 46 and the second surface 48. The two through-holes 54A, 54B are filled by the elastic material of the sealing body 38. At least one of the two through-holes 54A, 54B forms the hollow 50.

[0062] According to an unrepresented variant, the locking insert 36 defines more than two through housings, for example three.

[0063] The body 44 has a radially internal end 56, on the side opposite the head 42, forming one or more teeth 58 adapted to bite into the plain end 16. In section along a radial plane (plane of [Fig.1]), the body 44 defines for example an angle y with the head 42.

[0064] In the example, the head 42 and the body 44, with the exception of the teeth 58, are completely overmolded by the sealing body 38.

[0065] The head 42 defines a front surface 60 (axially to the side of the plain end 16) intended to be substantially parallel to the surface 28 when the locking insert 36 is braced, the head 42 also butting against the bottom 32 of the groove 24.

[0066] The teeth 58 are for example four in number. The teeth 58 are advantageously arranged successively along a convex curve C, the convexity of which is turned towards the plain end 16, so that forces F of the locking insert 36 on the plain end 16 are concentrated on a subgroup of the teeth 58, for example on two of the teeth.

[0067] One of the two through dwellings 54A, 54B is located for example in head 42.

[0068] The other of the two through housings 54A, 54B is located for example in the body 44, or at the junction between the body 44 and the head 42.

[0069] The two through-holes 54A, 54B are, for example, cylindrical. They have the same diameter DI, advantageously between 2 and 5 mm. First variant

[0070] With reference to [Fig. 3], a locking insert 36A is described according to a first variant. The locking insert 36A is analogous to the locking insert 36 shown in Figures 1 and 2. Similar elements bear the same numerical references and will not be described again. Only the differences will be described in detail below.

[0071] The locking insert 36A does not define the two through housings 54A, 54B.

[0072] The locking insert 36A defines four blind holes 62A, 62B, 62C, 62D extending in the circumferential direction, for example substantially perpendicular to the first surface 46 and the second surface 48. At least one of the four blind holes forms the hollow 50.

[0073] According to variants not shown, the locking insert 36A defines more than four blind holes.

[0074] The blind holes 62A, 62C are defined by the first surface 46, and the blind holes 62B, 62D are defined by the second surface 48.

[0075] The blind holes 62A, 62C are respectively opposite the blind holes 62B, 62D in the circumferential direction.

[0076] The four blind holes 62A, 62B, 62C, 62D are filled by the elastic material of the sealing body 38.

[0077] The four blind holes 62A, 62B, 62C, 62D are for example cylindrical and advantageously have the same diameter D2 equal to the diameter DI.

[0078] The blind holes 62A, 62B, 62C, 62D have for example a depth H1 (in the circumferential direction) between 2 and 5 mm.

[0079] The two blind holes 62A, 62B are located for example in the head 42.

[0080] The two blind holes 62C, 62D are located, for example, in the body 44, or at the junction between the body and the head.

[0081] In the example, the four blind holes 62A, 62B, 62C, 62D can be considered as initial parts (closest to the surface of the locking insert) of the through-holes 54A, 54B of the locking insert 36. In other words, the locking insert 36A is derived from the locking insert 36 by obstructing a central part (in the circumferential direction) of the through-holes 54A, 54B. Second variant

[0082] With reference to [Fig. 4], a locking insert 36B is described according to a second variant. The locking insert 36B is analogous to the locking insert 36A shown in [Fig. 3]. Similar elements bear the same numeral references and will not be described again. Only the differences will be described in detail below.

[0083] The locking insert 36B does not define four blind holes, but four protrusions 64A, 64B, 64C, 64D for example located in the same places as the blind holes of the locking insert 36A.

[0084] According to variants not shown, the locking insert 36B defines more than four protrusions.

[0085] The four protrusions 64A, 64B, 64C, 64D are embedded in the sealing body 38.

[0086] The two prominences 64A, 64C are defined by the first surface 46, and the other two prominences 64B, 64D are defined by the second surface 48.

[0087] The four protrusions 64A, 64B, 64C, 64D are, for example, cylindrical and advantageously have a diameter D3 equal to the diameter D2. The protrusions 64A, 64B, 64C, 64D have, for example, the same length H2 (in the circumferential direction) equal to the depth HL

[0088] In the example, the four protrusions 64A, 64B, 64C, 64D can be considered as the "negatives" (or mirror images) of the blind holes 62A, 62B, 62C, 62D. Third variant

[0089] With reference to [Fig. 5], a locking insert 36C is described according to a third variant. The locking insert 36C is analogous to the locking insert 36 shown in Figures 1 and 2. Similar elements bear the same numerals and will not be described again. Only the differences will be described in detail below.

[0090] The locking insert 36C does not define the two through housings 54A, 54B.

[0091] The body 44 of the locking insert 36C includes a radially external surface 66 forming a back.

[0092] The surface 66 defines at least one T-shaped groove 68 forming the hollow 50. The groove 68 extends in the circumferential direction.

[0093] Due to its "T" shape, the groove 68 defines a housing 70 whose entrance is formed by two lips 72 facing each other.

[0094] The elastic material of the body 38 fills the groove 68. Fourth variant

[0095] With reference to [Fig. 6], a locking insert 36D is described according to a fourth variant. The locking insert 36D is analogous to the locking insert 36C shown in [Fig. 5]. Similar elements bear the same numerals and will not be described again. Only the differences will be described in detail below.

[0096] The locking insert 36D does not define a groove 68, but at least a T-shaped rail 74 located in the same place as the groove 68 and forming a protrusion 76.

[0097] Rail 74 extends in the circumferential direction.

[0098] The sealing body 38 overmolds the rail 74. Fifth variant

[0099] With reference to [Fig. 7], a locking insert 36E is described according to a fifth variant. The locking insert 36E is analogous to the locking insert 36 shown in Figures 1 and 2. Similar elements bear the same numerals and will not be described again. Only the differences will be described in detail below.

[0100] The locking insert 36E does not define the two through-holes 54A, 54B, but at least one through-hole 78 extending in a radial plane P with respect to the central axis X. The through-hole 78 defines the recess 50.

[0101] Compared to a through-hole or blind hole oriented in the circumferential direction, the orientation in a radial plane has the advantage of reducing mechanical stresses within the locking insert 36E, by reducing the internal surfaces subjected to a bending moment created by the buttress.

[0102] The through housing 78 extends between two surfaces 66, 80 of the body 44 which are radially opposed to each other. Sixth variant

[0103] With reference to [Fig. 8], a locking insert 36F is described according to a sixth variant. The locking insert 36F is analogous to the locking insert 36E shown in [Fig. 7]. Similar elements bear the same reference numerals. The numerical aspects will not be described again. Only the differences will be described in detail below.

[0104] The through housing 78 does not extend between the two radially opposed surfaces 66, 80 of the body 44.

[0105] The through housing 78 opens on one side onto a radially external surface 82 defined by the head 42 and located opposite the bottom 32 of the groove 24. The through housing 78 also opens on the other side onto the front surface 60. Combination of the preceding variants

[0106] It should be noted that the locking insert variants 36, 36A to 36F above are possibly combinable with each other, i.e. that the hollows and / or protrusions of these variants can be added to each other.

[0107] Thanks to the characteristics described above, the tubular joint 10 is efficient and cost-competitive. The tubular joint 10 is easy to implement because the sealing gasket 18 is easily installed, with the locking inserts 36, 36A to 36F being correctly fixed to the sealing body 38. Production and recycling of the tubular joint 10 are also facilitated.

Claims

1. Demands Tubular junction (10) comprising: - a snap-fit ​​end (12) defining a central axis (X) and a housing (14), - a plain end (16) adapted to be inserted into the housing (14) along the central axis (X) to reach a position fitted relative to the fitting end (12), and - a sealing gasket (18) located radially with respect to the central axis (X) between the plain end (16) and the push-fit end (12) when the plain end (16) is in the push-fit position, the sealing gasket (18) comprising: - a sealing body (38) made of elastic material extending around the central axis (X) and being at least partially situated in an annular groove (24) defined by the socket end (12), the sealing body (38) comprising a portion (40) radially compressed between the plain end (16) and the socket end (12) when the plain end (16) is in the socketed position, and - a plurality of locking inserts (36; 36A to 36F) distributed angularly around the central axis (X), each of the locking inserts (36; 36A to 36F) comprising: - a head (42) located in the groove (24), and - a body (44) extending obliquely with respect to the central axis (X) between the head (42) and the plain end (16) and having a radially inward end (56), on the side opposite the head (42), forming one or more teeth (58) adapted to bite into the plain end (16), each of the locking inserts (36; 36A to 36F) being adapted to brace between the groove (24) and the plain end (16) to prevent disengagement of the plain end (16) from the socket end (12), each of the locking inserts (36; 36A to 36F) being at least partially overmolded by the sealing body (38), and defining at least one recess (50; 62A to 62D; 68) or comprising at least one protrusion (64A to 64D; 76; 74), the hollows (50; 62A to 62D; 68) or protrusions (64A to 64D; 76; 74) being adapted to fix each of the locking inserts (36; 36A to 36F) onto the sealing body (38) by complementary shape, characterized in that:

2. - each of the locking inserts (36) defines at least two through-holes (54A, 54B) extending circumferentially around the central axis (X) and filled by the sealing body (38); or - each of the locking inserts (36A) defines at least four blind holes (62A, 62B, 62C, 62D) extending in the circumferential direction, two of the four blind holes (62A, 62B, 62C, 62D) being defined by a first surface (46) of each of the locking inserts (36A), and two other of the four blind holes (62A, 62B, 62C, 62D) being defined by a second surface (48) of each of the locking inserts (36A), the second surface (48) being opposite the first surface (46) in the circumferential direction, two of the four blind holes (62A, 62B, 62C, 62D) being respectively opposite two other of the four blind holes (62A, 62B, 62C, 62D) in the direction circumferential, the four blind holes (62A, 62B, 62C, 62D) being filled by the sealing body (38); or - each of the locking inserts (36B) defines at least four protrusions (64A, 64B, 64C, 64D) extending in the circumferential direction, two of the four protrusions (64A, 64B, 64C, 64D) being defined by a first surface (46) of each of the locking inserts (36B), and two other protrusions (64A, 64B, 64C, 64D) being defined by a second surface (48) of each of the locking inserts (36B), the second surface (48) being opposite the first surface (46) in the circumferential direction, two of the four protrusions (64A, 64B, 64C, 64D) being respectively opposite two other protrusions (64A, 64B, 64C, 64D) in the direction circumferential, the four protrusions (64A, 64B, 64C, 64D) being recessed into the sealing body (38); or - the body (44) of each of the locking inserts (36C; 36D) comprises a radially external surface (66), said surface (66) defining either a rail (74) or a T-groove (68), the rail (74) or the groove (68) extending in the circumferential direction, the sealing body (38) filling the groove (68) or overmolding the rail (74). Tubular junction (10) according to claim 1, wherein the sealing gasket (18) is devoid of a layer adhesion applied to each of the locking inserts (36; 36A to 36F).

3. Tubular junction (10) according to claim 1 or 2, wherein each of the locking inserts (36; 36A to 36F) is fixed to the sealing body (38) solely by complementarity of form.

4. Tubular junction (10) according to any one of claims 1 to 3, wherein each of the locking inserts (36E; 36F) defines at least one through housing (78) extending in a radial plane (P) with respect to the central axis (X).

5. Tubular junction (10) according to claim 4, wherein the through housing (78) extends between two surfaces (66, 80) of the body (44) of each of the locking inserts (36E), the two surfaces (66, 80) being radially opposed to each other.

6. Tubular junction (10) according to claim 5, wherein the through housing (78) opens onto a radially external surface (82) defined by the head (42) of each of the locking inserts (36F), said surface (82) being opposite a bottom (32) of the groove (24).