GASKET FOR A SEALED WIRING CONNECTION OF AN ENCLOSURE

Description

[0001] The present invention relates to a sealing gasket for a sealed wiring port of a housing. This invention finds its application more particularly in sealed housings intended to receive optical fibers for their connection with optical branches.

[0002] In the field of optical cables, there are several diameter sizes. In particular, a main optical cable can include several optical modules, each containing several optical fibers. A main cable can have an external diameter of more than ten millimeters, and can, for example, include up to 24 modules, these modules, each a few millimeters in diameter, can themselves include up to 24 optical fibers, the optical fibers each having a diameter of around a hundred micrometers. From this fact, it appears obvious that the external diameters of the cables to be connected are variable, there is a need to ensure the sealing of these cables, whatever their diameter, at the wiring port of the box.

[0003] Housings are known to have a cable gland at the wiring port through which the cable is introduced into the housing. These cable glands are problematic because the quality of the seal is a function of the compression applied by the gland, to the point where a cabling operator will tend to seek maximum manual compression when placing the cable in the gland. These compressions on the optical cable create local stresses by compressing the material so that the quality of a signal carried by this cable can be negatively impacted at these stress points.

[0004] Sealing solutions for incoming and / or outgoing wiring ports of waterproof enclosures are always dependent on the different cable diameters that are intended to pass through the same port. The greater the range of diameters, the greater the number of seals required to accommodate this range. The challenge is to have a minimum number of seals, or even a single seal that covers different possible cable diameters at this wiring port.

[0005] Document WO2019-195109 discloses a single sealing gasket adaptable to a fixed number of cable diameter sizes. According to one embodiment, this gasket is intended to be able to adapt to five distinct cabling diameters. This document teaches a body provided with a base and surmounted by a tube provided with several concentric cylindrical stages of internal diameters smaller than each other as the distance from the base increases. This type of gasket is intended to form both an outlet port of a wiring box and at the same time ensure the sealing of this wiring port. The operation of this type of gasket is to be cut at one of the five diameters to provide the diameter adapted to the cable passing through it. Therefore, this type of gasket is for single use, when it is desired to use it for new cabling with a thinner cable.

[0006] Publication US 2004 / 161970 A1 discloses a connector for a coaxial cable, the coaxial cable comprising a spirally corrugated outer conductor and an inner conductor. The connector comprises a connector interface at one end of the connector, a hollow cylindrical body and an inner contact. The connector interface is coupled to the hollow cylindrical body. The body has an inner surface comprising an internal helical groove section at one end of the cable and a stopper at the connector end of the internal helical groove section.

[0007] The invention thus proposes modularity of sealing solutions making it possible to limit the number of accessories required to equip a waterproof housing at its input and / or output ports.

[0008] The invention relates to a sealing gasket for a cable port of a housing, said gasket comprising a deformable body, this deformable body being a through-body and comprising a base, a collar and a corrugated tube between the base and the collar, this body being a unit such that the collar and the base have minimum internal diameters respectively greater than a minimum internal diameter of the corrugated tube, the corrugated tube comprising internal corrugations and external beads, such that an external bead is arranged axially between two adjacent internal corrugations, and such that at least two adjacent internal corrugations respectively have two of these minimum internal diameters, the corrugated tube comprising external annular grooves, such that an external bead is located between two external annular grooves,the outer bead has a radial thickness less than a radial thickness at the right of these outer annular grooves.,

[0009] Thus the deformable character of the body comes from its particular structure and the variations in thickness observed in the base and the collar, and more particularly those of the corrugated tubing.

[0010] In particular, the minimum internal diameters for the collar and the base may be at least 1.1 times; better still at least 1.4 times the minimum internal diameter of the corrugated tubing. More particularly, these dimensional ratios are determined in the absence of stresses exerted on the body, in other words, without deformation of the body.

[0011] Advantageously, at least two adjacent internal corrugations respectively have strictly different internal diameters, such that an external bead arranged between these two adjacent internal corrugations has an inner diameter greater than the respective local minimum inner diameters of these two adjacent corrugations, and a maximum outer diameter greater than the respective local outer diameters of these two adjacent corrugations.

[0012] In such a configuration, an external bead may be arranged between these two grooves and have both an internal diameter greater than the respective local minimum internal diameters of these two adjacent grooves, and / or a maximum external diameter greater than the respective local maximum external diameters of these two adjacent grooves, these local maximum external diameters corresponding to the line of the external annular grooves.

[0013] The corrugated tubing may also comprise internal corrugations such that at least two adjacent internal corrugations respectively have the same local minimum internal diameter, preferably this same minimum internal diameter may be the minimum internal diameter of the entire corrugated tubing 13, or even of the joint as such, so that a double annular seal is thus proposed for cables of smaller diameters.

[0014] Preferably, the corrugated tubing may be radially expandable such that adjacent inner corrugations of the corrugated tubing may have, under stress, for example under stress from a cable passing through the seal, an identical inner diameter.

[0015] More particularly, the corrugated tubing may comprise at least four adjacent corrugations, for example such that these corrugations each have an increasing local minimum internal diameter.

[0016] Alternatively, the minimum internal diameter of the corrugated portion may be presented by a corrugation arranged between two adjacent corrugations of local minimum internal diameter greater than this minimum internal diameter.

[0017] Preferably, the collar and the base may have external diameters greater than those of the corrugated tubing in order to ensure the tight constriction around the cable only at the level of the corrugated tubing, the structure of which allows flexible adaptation around the cable. In particular, these external diameters of the collar and the base may be greater than that of a bead located between two external annular grooves of the corrugated tubing. With such a configuration, the corrugated tubing can deform radially in the volume of the envelope surface defined by the collar and / or the base.

[0018] According to one embodiment, the corrugated tubing may be delimited by two axially opposite corrugations.

[0019] According to a preferred embodiment, the corrugated tubing can be axially deformable, so that the seal can adapt to the manufacturing tolerances of the sealed housings and in particular to the dimensional manufacturing tolerances of the inlet and / or outlet ports of these housings.

[0020] The invention also relates to an assembly comprising a sealed housing provided with a cable port, a seal according to the invention equipping this cable port and a cable, in particular an optical fiber, the cable passing through this seal so that an internal annular seal is formed between the seal and the cable and in that an external annular seal is obtained between the seal and the cable port.

[0021] Preferably, this assembly comprises a plug provided with a cable support arm, the seal being disposed in the plug when the plug is mounted on the port, such that a radial annular seal can be obtained between the plug and the seal. by the base comprising an external radial groove capable of coming into sealed contact with an internal wall of the port plug, and or by the collar having an external diameter greater than the diameter of this internal wall.

[0022] More particularly in the assembled position of the cap on the port, the seal may come into annular sealing contact with a rim of the inlet port. Brief description of the drawings

[0023] The accompanying drawings illustrate the invention: [ Fig. 1 ] represents an external profile view of a seal according to the invention [ Fig. 2] represents a longitudinal sectional view of a joint according to the invention, and in particular corresponding to the joint of the Figure 1 ; [ Fig. 3 ] represents an exploded sectional view of an assembly according to the invention comprising a sealing joint according to the invention such that the view of the Figure 3 cuts the joint along a longitudinal cutting plane identical to that of the Figure 2 ; [ Fig. 4 ] represents an assembled sectional view of an assembly according to the Figure 3 . [ Fig. 5] and [Fig. 6 ] represent longitudinal sectional views of joints according to the invention implemented with cables of different external diameters. Description of embodiment(s)

[0024] There Figure 1represents a seal 1 according to the invention. The seal 1 comprises a tubular body 2. This tubular body 2 is deformable. It can be made of an elastomeric material, a silicone, a rubber, an EPDM or a synthetic resin. The material is chosen so that the body 2 can be produced integrally by molding, printing or injection. It is preferably flexible.

[0025] The body 2 has a longitudinal axis X also forming an axis of symmetry. The body 2 passes through along the axis X. The body 2 has two opposite ends relative to the axis X, respectively 3 and 4. A first end 3 delimits a base 5, and the second end 4 delimits a collar 6. The base 5 has an opening 7 opening onto an internal tubular space opening through an opening 8 in the collar 6.

[0026] In the example shown, the openings 7 and 8 each define a circular circumference, the base 5 has an outer circumference of cross-section to the X axis which is also circular. The body 2 is intended to be crossed by a cable, very generally of circular section. On the other hand, as regards the outer circumference of the base 5, like the collar 6, other shapes can be produced to adapt to specific housing housings, depending on the geometry of a housing of the cable port in which the seal must be placed.

[0027] In particular, the outer periphery of the base 5 comprises a wall parallel to the axis X provided with an annular groove 9 to be retained by snap-fastening in a recess of said housing. The base 5 is axially delimited between, on the one hand, the opening 7 and, on the other hand, the groove 9.

[0028] As shown in the Figure 2, the outer periphery and the inner periphery of the collar 6 are of circular and concentric sections. This collar 6 comprises three successive sections 10, 11 and 12. Two cylindrical sections 10 and 12 are separated by a truncated cone section 11, such that the three sections have the same internal diameter Dic, which turns out to be a minimum internal diameter of the collar 6. The external diameters of the sections of the collar 6 progressively decrease D10, D11 and D12 as one moves away from the opening 8, along the axis X.

[0029] The first section 10 is adjacent to the opening 8 and forms a section of greater radial thickness of this collar, so that this excess thickness of the first section 10 gives a certain radial, but also longitudinal, local rigidity to the seal.

[0030] Between the base 5 and the collar 6 extends a corrugated tube 13. This corrugated tube has both an internal diameter that varies along the axis X, but also an external diameter that varies along this same axis X, such that these variations do not have the same amplitude, nor are they superimposable. Thus, the corrugated tube 13 has internal corrugations 14 and external beads 15. The corrugations, as well as the beads, are of circular cross-section and adjacent to each other, so that a bead such as 14 is arranged between two adjacent corrugations such as 14. A minimum internal diameter of the corrugated tube is presented by a local minimum internal diameter of one of the corrugations.

[0031] A corrugation 14 is characterized according to this example by a portion of a tubular body, this portion having a strong local constriction of the internal diameter locally defining a minimum internal diameter. Two adjacent corrugations can have the same minimum local internal diameter D14. In the embodiment shown, figure 2 , the corrugated tubing comprises five adjacent corrugations 14a, 14b, 14c, 14d and 14e, such that the first two adjacent corrugations 14a and 14b, together adjacent to the collar 6, have a minimum internal diameter D14a and D14b respectively equal, and in that the three other successive corrugations 14c, 14d and 14e in the direction of the base 5 have local minimum internal diameters D14c, D14d and D14e which increase from the collar 6 in the direction of the base 5. The corrugations D14a and D14e longitudinally delimit the corrugated tubing 13, along the axis X.

[0032] In particular we can have in this example D 14 a = D 14 b And D 14 d = D 14 e ∗ k D 14 c = D 14 d ∗ k et And D 14 b = D 14 c ∗ k where k is between 0.95 and 0.98. The k value can be the same or different from one ring to another.

[0033] Alternatively, we can have D14a = D14b and D 14 d = D 14 e − g D 14 c = D 14 d − g et And D 14 b = D 14 c − g

[0034] Where g is a finite quantity, for example constant from a given corrugation to an adjacent corrugation. g is for example 1 mm, and D14a equal to 3 mm.

[0035] The factors k and g can be a function of the desired radial strain rate, the number of corrugations, the size of the port in the casing. The inside diameters at the corrugations are a series of minimum local inside diameters of the corrugated tubing.

[0036] Figure 5, an internal annular constriction 16 is observed in the base 5, such that this constriction 16 has a minimum local internal diameter greater than all the minimum internal diameters of all the corrugations 14 of the corrugated tube 13. The minimum internal diameter Die of the base 5 is represented by the internal diameter at the constriction 16. The minimum internal diameter Die is greater than each minimum local internal diameter of each of the corrugations 14 of the corrugated tube 13.

[0037] The minimum internal diameter Dic of the collar 6 is also greater than each minimum local internal diameter of each of the corrugations 14 of the corrugated tube 13.

[0038] The corrugated tubing 13 is such that between two adjacent corrugations, it has a bead 15. Thus in the example presented, there are four beads 15a, 15b, 15c and 15d. The beads are spaced from each other by an external annular groove 16 respectively. In this example, there are thus three annular grooves 16a, 16b and 16c. The bead 15b is thus arranged between the grooves 16a and 16b, and similarly the bead 15c is arranged between the grooves 16b and 16c. The beads each have an external diameter greater than that of the grooves which surround it. The beads have very slightly truncated cone-shaped portions, and have on their inner periphery a portion of inner diameter, for example greater than 1.1 times to at least 1.25 times the minimum inner diameter of the adjacent corrugations. Thus, the bead 15a has an inner diameter of the order of 1.1 to 1.25 times the minimum internal diameter of one of the two, or even both, adjacent corrugations 14a and 14b. And so on for the other beads.

[0039] The beads 15 have a radial thickness less than a radial thickness at the annular grooves 16. More particularly, a radial thickness of the annular tubing can pass through minima at the junctions formed by these external annular grooves between beads such as 15 and the local minimum internal diameters of the corrugations such as 14. These minimum thicknesses promote the deformability of the corrugated tubing 13. The beads 15 have a radial thickness less than a radial thickness at the corrugations 14.

[0040] The annular grooves 16a, 16b and 16c represent the locations where the corrugated tubing has minimum outside diameters. All of the grooves may have the same minimum outside diameter, or only some or even one of the grooves may have this minimum outside diameter for the entire tubing 13.

[0041] In the example shown, the annular grooves 16a, 16b and 16c are respectively arranged in line with, and form the outer periphery along the axis X, of the grooves 14, in particular the grooves 14b, 14c and 14d.

[0042] This structure of the corrugated tubing gives it a capacity for radial deformation, made possible by the free volume defined by the outer periphery of the corrugated tubing and a generatrix of the base 5 and / or the collar 6. In fact, when the seal is placed in a housing port, this port defines a housing with a volume delimited by a generatrix of the largest diameter between that of the base and / or the collar.

[0043] To improve the rigidity of the joint, a radial thickness of the wall forming the corrugated tube 13 is maximum at the corrugation 14e adjacent to the base 5. In particular, this radial thickness at the corrugation adjacent to the base can be substantially equal, namely between 90% and 110% of the value of the radial thickness of the portion 10 of the collar 6.

[0044] According to the exploded view of the figure 3, the installation of a seal 1 in a housing 17 requires unscrewing a cap 18 having a cable holder 19, and housing the base 5 of the seal inside the cap 18, in order to then allow secure docking of the seal in a housing 20 of the housing, and additional screwing of the cap 18 around this housing 20. The housing defines a cable port of this housing.

[0045] As represented in the Figures 5 and 6 , when the external diameter of the cable Dc is between the values of the different internal diameters D14a, D14b, D14c, D14d and D14e of the corrugations respectively 14a, 14b, 14c, 14d and 14e, it is observed that only the corrugations with an internal diameter less than Dc deform radially in order to respectively ensure an annular seal around this cable. At the Figure 5 , we thus observe a double radial seal around the small diameter cable. At the figure 6, the cable shown has an outside diameter Dc greater than all the local minimum “unstressed” inside diameters of the corrugations of the corrugated tubing 13, but nevertheless less than the minimum outside diameters of the base 5 and the collar 6, respectively Die and Dic. Thus the tubing deforms radially in order to ensure a sealed internal contact with the cable, and thus lead to a placement of this seal in the housing 20 always identical whatever the outside diameter of the cable placed in the housing.

[0046] The cap 18 is screwed relative to the housing 20 with always the same number of screw turns, in particular a quarter turn, whatever the diameter of the cable. This uniformity of screwing makes it possible to ensure reliable waterproof installation of the cable in the housing, without affecting the signal transmission capabilities. On the one hand, the collar 6 provides radial sealing with the housing 20, and on the other hand, the base 5 provides radial sealing with the cap 18.

[0047] The object of the invention is to thus allow adaptability of the seal to different types of cable diameters, while not requiring any seal preparation step for the operator responsible for placing it in the housing.

Claims

1. Seal (1) for a cable port (20) of a casing, said seal comprising a deformable body (2), this deformable body passing therethrough and comprising a base (5), a flange (6) and corrugated tubing (13) between the base and the flange, the body being unitary, the flange and the base having minimum inner diameters (Dic, Die) that are larger than a minimum inner diameter of the corrugated tubing, the corrugated tubing comprising inner corrugations (14) and outer beads (15) such that an outer bead is arranged axially between two adjacent inner corrugations, and such that at least two adjacent inner corrugations respectively have minimum local inner diameters, the corrugated tubing comprising outer annular grooves (16) such that an outer bead is located between two outer annular grooves, the outer bead having a radial thickness that is smaller than a radial thickness in line with these outer annular grooves (16).

2. Seal according to Claim 1, wherein at least two adjacent inner corrugations respectively have strictly different minimum inner diameters, and an outer bead arranged between these two adjacent inner corrugations has an inner diameter that is larger than the respective local minimum inner diameters of these two adjacent corrugations, and a maximum outer diameter that is larger than the respective local outer diameters of these two adjacent corrugations.

3. Seal according to Claim 1 or 2, wherein the corrugated tubing comprises inner corrugations (14) such that at least two adjacent inner corrugations respectively have strictly identical minimum inner diameters.

4. Seal according to Claim 1 or 2, wherein the corrugated tubing is radially expandable so that adjacent inner corrugations of the corrugated tubing may have an identical inner diameter when stressed by a cable passing through the seal.

5. Seal according to any one of Claims 1 to 4, wherein the corrugated tubing comprises at least four adjacent corrugations.

6. Seal according to any one of Claims 1 to 5, wherein the flange and the base have outer diameters that are larger than that of a bead located between two outer annular grooves of the corrugated tubing.

7. Seal according to any one of the preceding claims, wherein the corrugated tubing is delimited by two corrugations (14a, 14e) at axially opposite ends.

8. Assembly comprising a sealed casing provided with a cable port, a seal according to any one of the preceding claims fitted to this cable port and a cable, in particular an optical fibre, passing through this seal so that inner annular sealing is formed between the seal and the cable and outer annular sealing is obtained between the seal and the cable port.

9. Assembly according to Claim 8, comprising a cover (18) provided with a support arm (19) for the cable, the seal being arranged in the cover when the cover is mounted on the port, such that radial annular sealing is obtained between the cover and the seal by - the base comprising an outer radial lip-seal (9) that can come into sealed contact with an inner wall of the cover of the port, and / or by - the flange having an outer diameter that is larger than the diameter of this inner wall.

10. Assembly according to Claim 9, wherein, when the cover is in the assembled position on the port, the flange comes into annular sealed contact with a rim of the inlet port.