Connector for rigid and / or flexible cables

Abstract

The invention relates to a connector (C) for connecting at least two rigid and / or flexible electrical cables (2, 3), the connector comprising a housing (1), a centring element (12) housed in the preferably metal housing (1) and a sealing element (14) of the housing, consisting of a polymer material. The invention is characterised in that it comprises a coating element (13) for coating the inner wall of the housing (1), positioned between the sealing element (14) and the housing (1), the coating element (13) consisting of thermoplastic polymer material.

Description

Description Title of the invention: Connector for rigid and / or flexible cable

[0001] The present invention relates to a connector for rigid and / or flexible cable, in particular a mineral-insulated cable. A connector according to the invention is specifically intended to form an interface between a rigid cable, such as a mineral-insulated shielded cable, and one or more flexible cables, or also between two rigid cables, for example between two mineral-insulated shielded cables, or even between flexible cables.

[0002] Mineral-insulated shielded cables are cables consisting of one or more metallic conductors and a cylindrical hollow metallic sheath surrounding the conductor(s) and between which is introduced a refractory insulator such as a mineral material of the type magnesia, alumina or silica, in powder or in the form of beads, the outer sheath being of stainless steel, copper or a Ni-Cr alloy such as that known under the trade name Inconel 600.

[0003] Rigid cables are particularly fire-resistant and used in industrial environments with hazardous areas such as military zones, space zones, or areas requiring high levels of cleanliness, such as in the semiconductor industry. They are used in numerous industrial sectors where components such as sensors, heating elements, or electrical signal transmission cables are employed, and these components must withstand increasingly harsh conditions such as vacuum, pressure, temperature, cryogenic conditions, radiation, humidity, etc.

[0004] Such cables are also used to connect devices that are spaced apart, and it is therefore necessary to provide means of connecting these cables to the devices, such as cables to each other or other types of cables such as flexible cables.

[0005] Cable connectors are extremely critical parts of these components as they must ensure electrical continuity of the conductors, prevent moisture migration into the insulation while preserving the dielectric strength of the cable.

[0006] In practice, this is often a weak point because it sometimes proves complicated. to bring together all these qualities when one is in a very hot environment.

[0007] Such a connector must therefore fulfill several functions: - an interface function between two rigid and / or flexible cables, - a sealing function to ensure that moisture does not enter the cable(s) and affect electrical performance, - an electrical function to guarantee a high level of electrical insulation and dielectric strength so as not to degrade performance, - a mechanical function, the connector must have sufficient mechanical strength to absorb vibrations or shocks related to the use of such cables in air transport, space transport, for example, without degradation or loss of performance.

[0008] A connector of this type includes: - a preferably metallic housing, providing the mechanical function of the connector, this housing being attached to a cable by crimping, welding or brazing, - Optionally, at least one electrical connector for joining the conductors of the cables to be connected; these electrical connectors can be brazed, crimped, or soldered. Some connectors do not have an electrical connector; the conductors of a mineral-insulated cable can be directly connected to a flexible cable, for example. - a centering element made of an electrically insulating material such as a polymer material to maintain the internal components of the connector, such as electrical fittings, conductors of the rigid cable and / or flexible cable, in a centered position, - a filling material for the metal housing that holds the various components inside the housing in place and ensures the connector is sealed against moisture ingress. This material is, in particular, a polymer such as a resin chosen from epoxy, acrylic, polyurethane, or silicone resins, which can fill the entire connector.

[0009] These electrical connectors, as mentioned previously, are used in the military and space sectors, where regular maintenance is difficult, if not impossible. Electrical connectors used on satellites, for example, must demonstrate very long-term performance.

[0010] The present invention therefore aims to provide a connector that exhibits all the functions already stated and that also has a sufïsam- lifespan lengthy process to be used in technical fields where it is difficult or even impossible to implement regular maintenance.

[0011] To this end, the invention proposes a connector for connecting at least two rigid and / or flexible electrical cables comprising a housing, a centering element housed in the housing and a sealing element of the housing, made of a polymer material, characterized in that it comprises a coating element for the internal wall of the housing, interposed between the sealing element and the housing, said coating element being made of a thermoplastic polymer material.

[0012] Advantageously, this coating element absorbs volume variations related to the polymerization of the sealing material in the housing, which is preferably metallic, and avoids residual stresses, particularly those related to the shrinkage of the sealing material during polymerization, thus promoting the extension of the service life of such a connector, which is thus optimized.

[0013] The sealing element consists of a polymer material that fills the housing, preferably metallic, and holds the various components contained within it, such as the centering element, in position, while also ensuring the connector is watertight. The sealing material is preferably a polymer, such as a resin polymerized within the housing. This sealing and housing-filling material, preferably metallic, thus encapsulates the various components inside the housing, holding them in place and ensuring the connector is watertight against moisture ingress. This polymer material is, in particular, a thermoplastic or thermosetting polymer, such as a resin chosen from epoxy, acrylic, polyurethane, or silicone resins, which can fill the entire connector.

[0014] Advantageously, the coating element consists of a polymer material chosen from thermoplastic polymers such as halogenated polymers, preferably fluorinated polymers such as polytetrafluoroethylene (PTFE), polyaryletherketone polymers, preferably polyetheretherketone (PEEK), polyamides, preferably poly(hexamethylene adipamide), 6 / 6 fiber known as Nylon or any other suitable organic polymer material, depending on the environments of use (temperature, radiation...) and sectors of activity (aeronautics, space, nuclear industry...).

[0015] Such an internal wall coating element therefore makes it possible to absorb the volume variations which, at the time of the resin polymerization process, occur depending on the size of the housing and / or the rate of temperature rise and fall during polymerization.

[0016] Furthermore, during polymerization, the sealing resin can form adhesions on the housing, particularly when it is metallic. These adhesions cause residual stresses in the sealing resin when it is removed at the end of the polymerization process. The coating element thus advantageously prevents the formation of adhesions between the metallic housing and the resin, thereby ensuring the connector's seal and maintaining excellent electrical performance over the long term.

[0017] Advantageously, the case is metallic such as, for example, stainless steel, nickel-plated brass or any other suitable metallic material and is in the form of a hollow body of cylindrical tubular shape which gives the case its mechanical strength.

[0018] Thus advantageously, the metal casing being in the form of a hollow metal body of cylindrical tubular shape, the cladding element is of cylindrical tubular shape complementary to the shape of said casing, preferably metallic.

[0019] Advantageously, the coating element is in the form of a layer of deposited material, such as, for example, by spraying, on the inner face of the hollow body of the housing.

[0020] The housing, preferably metallic, is advantageously secured to at least one rigid and / or flexible cable by crimping, welding or brazing.

[0021] The housing optionally includes electrical connectors for joining the conductors of the cables to be connected, whether rigid and / or flexible. These electrical connectors can be brazed, crimped, or soldered. In some connectors, there are no electrical connectors; the conductive element(s) of a mineral-insulated cable can be directly connected to one or more conductive elements of a flexible cable.

[0022] Advantageously, the centering element is cylindrical in shape, the dimensions of which are configured to fit inside the housing, preferably metallic and coated with the coating element, this centering element having at least one through hole, configured to receive at least one electrical fitting such as an electrical connection pin, at least one cable conductive element.

[0023] This centering element is made of an electrically insulating polymer material chosen from thermoplastic polymers such as halogenated polymers, preferably fluorinated polymers such as polytetrafluoroethylene (PTFE), polyaryletherketone polymers, preferably polyetheretherketone (PEEK), polyamides, preferably poly(hexamethylene adipamide), 6 / 6 fiber known as Nylon or an electrically insulating material such as a ceramic, in particular such as Al2O3, to maintain in a centered position the internal components of the connector such as electrical fittings, the conductive elements of the cables to be connected.

[0024] The materials constituting the different elements of the connector are advantageously chosen according to the environments of use (temperature, radiation...) and the sectors of activity (aeronautics, space, nuclear industry...).

[0025] The invention will be well understood and other aspects and advantages will become clear upon reading the following description, given by way of example with reference to the attached drawing plate on which is shown:

[0026] [Fig. 1] a longitudinal cross-sectional view of a connector according to the invention.

[0027] The connector C according to the invention comprises a metal housing 1, for example made of stainless steel, nickel-plated brass, or any other suitable metallic material. This metal housing 1 is in the form of a hollow, cylindrical, tubular metal body 11, which provides the housing 1 with its mechanical strength.

[0028] This hollow body 11 has a first end 111 intended to be connected to a first rigid electrical cable 2 such as a mineral-insulated shielded cable and a second end 112 intended to be connected to electrical cables, for example flexible 3. The end 111 is thus configured to be mounted on the end of said cable 2.

[0029] A lining element 13 is fitted to the inner face of the hollow body 11. This lining element 13 is a cylindrical, tubular mechanical part configured to extend against the inner face of the hollow body 11. The lining element 13 is mounted in the hollow body by a form-fitting mechanism. Alternatively, this lining element 13 can be made as a layer of material deposited by spraying.

[0030] This coating element 13 is preferably made of a polymer material selected from thermoplastic polymers such as halogenated polymers, preferably fluorinated polymers such as polytetrafluoroethylene (PTFE), polyaryletherketone polymers, preferably polyetheretherketone (PEEK), polyamides, preferably poly(hexamethylene adipamide), 6 / 6 fiber known as Nylon or any other suitable organic polymer material.

[0031] Within this hollow body 11, coated with the coating element 13, is housed a cylindrical block-shaped element 12, whose dimensions are configured to fit within the hollow body 11 coated with the coating element 13. This element 12 has at least one through-hole 121, in the example shown here two, configured to receive a connecting pin 5 respectively. This cylindrical block-shaped element thus forms a centering element 12 allowing the internal components, such as the connecting pins 5, to be held inside the hollow body 1, at a distance from each other and at a distance from the hollow body 11.

[0032] The centering element 12 can be made of polymer material such as PTFE or a ceramic such as Al2O3.

[0033] Each connecting pin 5 has one end intended to be connected to a conductive element 21 of the mineral-insulated cable. Its other end is intended to be connected to a conductive element 31 of a flexible cable 3.

[0034] The hollow body 11 is further filled with a polymer material 14 which ensures that the various elements, such as the centering element, the conductive elements 21, and the connecting pins 5, remain in position within said hollow body 11, and also ensures the sealing of the connector C thus formed to prevent the ingress of moisture. Such a polymer material 14 is, for example, an epoxy resin.

[0035] When the epoxy resin polymerization occurs, the polytetrafluoroethylene (PTFE) coating element 13 absorbs the mechanical stresses of the polymerizing resin and avoids residual stresses in the resin.

[0036] This coating element 13 allows the volume variations linked to the polymerization of the sealing material in the metal housing 1 to be absorbed and helps to avoid residual stresses in particular linked to the shrinkage of the sealing material during polymerization, absorbing the variations preventing adhesions from occurring between the metal housing 11 and the sealing resin during polymerization.

[0037] This coating element 13 thus makes it possible to improve the quality of the connector C according to the invention, in particular by promoting the preservation of electrical performance over a longer life.

[0038] In the example shown, the housing 1 of connector C is attached to a cable 2 such as a rigid cable and two flexible cables 3.

[0039] The rigid cable 2 is, for example, a mineral-insulated shielded cable consisting of two metallic core conductors 21 and a hollow, cylindrical metallic sheath 22 surrounding said core conductors 21, between which is inserted a powdered refractory insulator such as a mineral like magnesia, alumina, or silica. The outer sheath 22 is made of stainless steel, copper, or a Ni-Cr alloy such as that known by the trade name Inconel 600.

[0040] The stripped ends of the conductive elements 21 are inserted respectively into one end 51 of a connecting pin 5 while the opposite end 52 of each connecting pin 5 receives the end of a conductive element 31 of a flexible cable 3. These elements are fixed by brazing for example.

[0041] Once the various elements such as the centering element 12, the electrical connection pins 5, are mounted in the hollow body 11 of the metal housing 1, the polymer material such as an epoxy resin is introduced and its polymerization is carried out in the hollow body 11 coated with the coating element 13.

[0042] Once the resin has polymerized, the metal casing 1 is made watertight against the external environment.

Claims

Demands

1. Connector (C) for connecting at least two rigid and / or flexible electrical cables (2, 3) comprising a housing (1), a centering element (12) housed in the housing (1) and a sealing element (14) of the housing, made of a polymer material, characterized in that it comprises a coating element (13) of the inner wall of the housing (1), interposed between the sealing element (14) and the housing (1), said coating element (13) being made of a thermoplastic polymer material.

2. Connector (C) according to claim 1, characterized in that the coating element (13) is made of a polymer material selected from thermoplastic polymers such as halogenated polymers, preferably fluorinated polymers such as polytetrafluoroethylene (PTFE), polyaryletherketone polymers, preferably polyetheretherketone (PEEK), polyamides, preferably poly(hexamethylene adipamide), 6 / 6 fiber known as Nylon.

3. Connector (C) according to any one of claims 1 or 2, characterized in that the housing (1) is metallic such as stainless steel, nickel-plated brass.

4. Connector (C) according to any one of claims 1 to 3, characterized in that the housing (1) is in the form of a hollow body (11) of cylindrical tubular shape.

5. Connector (C) according to claim 4, characterized in that the coating element (13) is of cylindrical tubular shape complementary to the shape of said housing (1).

6. Connector (C) according to claim 4, characterized in that the coating element (13) is in the form of a layer of material deposited, such as by spraying, on the inner face of the hollow body (11) of the housing (1).

7. Connector (C) according to any one of claims 1 to 6, characterized in that the centering element (12) is in the form of a cylindrical block, the dimensions of which are configured to fit into the housing (1) covered by the covering element (13), this centering element (12) having at least one through hole (121), configured to receive at least one electrical connection such as an electrical connection pin, at least one cable conductive element.

8. Connector (C) according to any one of claims 1 to 7, characterized in that the centering element (12) is made of an electrically insulating polymer material selected from thermoplastic polymers such as halogenated polymers, preferably fluorinated polymers such as polytetrafluoroethylene (PTFE), polyaryletherketone polymers, preferably polyetheretherketone (PEEK), polyamides, preferably poly(hexamethylene adipamide), 6 / 6 fiber known as Nylon, or an electrically insulating material such as a ceramic such as Al2O3.

9. Connector (C) according to any one of claims 1 to 8, characterized in that the sealing element (14) is made of a polymer material which fills the housing (1) and allows the various elements contained in said housing, such as the centering element (12), to be held in position in said housing (1), and to ensure the sealing of the connector (C).

10. Connector (C) according to claim 9, characterized in that the polymer material is a thermoplastic or thermosetting polymer material such as a resin selected from epoxy, acrylic, polyurethane or silicone resins.

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