DK2433339T3 - The vapor-proof electrical apparatus and a process for its preparation - Google Patents

Description

Description Technical field [0001] The present invention generally relates to the enclosure of electronics. Specifically, the invention relates to electrical devices that include damp barriers arranged on an electric cable adapted to be utilized at electrical bushings and as connectors.

State of the art [0002] Electric cables are used for energy transmission or for electronic communication. Most electrical devices as well as the electrically conducting parts of the electric cables ought to be protected from water, because water conducts electricity and may give rise to damages due to corrosion or functional atmospheric disturbances. Therefore, most electrical devices, or at least the most sensitive electronic parts of these devices, are enclosed in one way or another and the electric cables includes an enclosing insulating sheath. But even though the electrical devices are enclosed in an efficient manner in some kind of housing there is still a risk that water penetrates at the cable bushings of the housing.

[0003] Connectors are used to connect electric cables, especially in connection to electrical bushings for enclosed electronics. In connectors that are commonly used today there are openings and cavities in and around the included parts where water may find its way to the inside.

Summary of the invention [0004] An object of the invention is to provide an electrical device that blocks damp penetration in and around electric cables and to provide a method that enables the possibility to produce such an electrical device. This object is achieved by means of an electrical device and a method of producing an electrical device according to the independent claims.

[0005] An electrical device according to the present invention includes an electric cable with an electrically conducting core enclosed by an insulating sheath. A moulded casting is arranged around the electric cable in a section along the electric cable of a length L1 and seals against the insulating sheath in at least a first outer section of a length L3 along the electric cable. The moulded casting of the insulating sheath penetrates and seals against the electrically conducting core in an inner section of a length L2 along the electric cable, wherein the electrical device 5 is damp proof along the electric cable 1.

[0006] The electrical device may be provided as a connector including at least one electrically conducting contact pin extending from the electrical device, which contact pin is connected to the current carrying core and partly included in the electrical device. The moulded casting seals against the contact pin and thus forms a complementary damp barrier.

[0007] The moulded casting may further be connected to, and preferably joined with, a casing, which casing may form a part of an enclosure for the electronics. Hence, the invention provides a complete damp barrier for an electrical bushing from one side of the housing to the other.

[0008] A method of producing a damp barrier including an electric cable with an electrically conducting core enclosed by an insulating sheath, which method includes arranging a moulded casting around the electric cable in a section of a length L1 and bringing it to seal with respect to the insulating sheath in at least a first outer section of a length L3,L4 along the electric cable, wherein the moulded casting or the housing is arranged to penetrate and seal with respect to the electrically conducting core in an inner section of a length L2 along the electric cable, whereby the electrical device is damp proofed along the electric cable.

[0009] In one embodiment of a method according to the present invention the insulating sheath is pre-treated by the application of heat and pressure around the insulating sheath in order to make the insulating sheath penetrate into the space around the core and its wires, if any, in order to seal with respect to the core in an inner section of a length L2 along the electric cable. Thereafter the moulded casting is arranged around the electric cable along a longer section of the electric cable including the inner section, wherein the moulded casting is brought to seal with respect to the insulating sheath. The arrangement of the moulded casting under increased pressure and temperature may give rise to an additional compression of the insulating sheath around the core beyond the compression occurring during the application of heat and pressure.

[0010] In another embodiment of a method according to the present invention the insulating sheath is removed at an inner section of a length L2 along the electric cable. Subsequently a moulded casting is arranged around the electric cable in a longer section of the electric cable including the inner section, wherein the moulded casting is brought to penetrate into the space around the core and its wires, if any, in order to seal with respect to the core and to seal with respect to the insulating sheath in a first and a second outer section of a length L3 and L4, respectively, along the electric cable, which outer sections are arranged on each side of the inner section.

[0011] Specific embodiments of the present invention are defined in the dependent claims. Other objects, advantages and new features of the invention will be apparent from the detailed description of the invention with reference to the accompanying drawings.

Short description of the drawings [0012] Below, the invention will be described in detail below with reference to the accompanying drawings, of which

Fig. 1 schematically shows a first embodiment of an electrical device according to the invention,

Fig. 2 schematically shows a second embodiment of an electrical device according to the invention,

Fig. 3 schematically shows a cross sectional view of an electrical device in the form of a connector according to the invention,

Fig. 4 schematically shows a first embodiment of contact pins and electric cables,

Fig. 5 schematically shows a second embodiment of contact pins and electric cables, and

Fig. 6 schematically shows.

Detailed description of preferred embodiments [0013] The present invention is based on the object to prevent transport of moisture or damp by means of capillary forces, i.e. to prevent transport of moisture via small open spaces along the electric cable on the inside or the outside of the insulating sheath. As mentioned above it is common knowledge that electrical bushings constitute a weak link in enclosed electric apparatuses. Often the transport of moisture occurs along the electric cable on the insulating sheaths outside, but may also occur along the conductive core on the inside of the insulating sheath. In particular the core consists of several wires where there is room for moisture to be transported between the wires along the electric cable.

[0014] In this application the term electric cable is used to denote the part that is often referred to as strand and the term current carrying core for the part often referred to as conductor. A strand, i.e. an electric cable, is the same as a conductor, i.e. a current carrying core, including its insulating sheath. Several strands may be arranged inside a protective housing. The conductor may consist of a single filament or it may consist of several filaments, in the following denoted wires. The wires may be arranged in parallel, but usually they are twisted. In order for the insulating sheath to be easily removed the wires are often lime-coated before extruding of the insulating sheath. Another option is to use a tube at the extrusion, which is arranged to house the wires.

[0015] Fig. 1 and 2 schematically illustrate an embodiment of an electrical device 5 according to the present invention including an electric cable 1 with an electrically conducting core 3 enclosed by an insulating sheath 2. A moulded casting is arranged around the electric cable 1 in a section along the electric cable of a length L1. The moulded casting 4 is in contact with the electric cable 1 and seals against the insulating sheath 2 in at least a first outer section of a length L3 along the electric cable 1. As is shown in Fig. 1 and 2 the corresponding sealing may also be provided in a second outer section of a length L4 along the opposite end of the electric cable 1 of the electrical device 5. In an inner section of a length L2 along the electric cable 1 a seal is provided with respect to the electrically conducting core 3. As is shown in Fig. 1 the moulded casting 4 is in contact with the insulating sheath 2 that penetrates and seals against the electrically conducting core 3. In a cross section of the electrical device along the electric cable a change of shape may be observed in the form of a reduced diameter of the insulating sheath in the inner section as a conesquence of that the insulating sheath has penetrated such that it fills the free space around the core 3, i.e. the insulating sheath appears to be compressed. The core 3 may change forms. As is shown in Fig. 2 the moulded casting 4 is in direct contact with the core 3 without intermediate insulating sheath and the moulded casting 4 penetrates and seals against the current carrying core 3. The seal with respect to the insulating sheath 2 in said outer section and the seal with respect to the core 3 in the inner section seals the capillary spaces where moisture could otherwise penetrate, and guarantees that the electrical device 5 is damp proof along the electric cable 1.

[0016] In one embodiment of the present invention the current carrying core 3 of the electrical device 5 includes wires 3a. The insulating sheath 2 or the moulded casting 4, whichever penetrates the inner section, substantially fills out the space between the wires 3a. The core 3 in the electric cable may be comprised of several wires 3a.

[0017] The electrical device may e.g. be in the form of a cable muff with included electric cable or a connector adapted to be part of an electrical bushing leading through a housing for enclosed electronics.

[0018] During the arrangement of the moulded casting 4 a compression of the insulating sheath 2 may occur such that the insulating sheath obtains a varying thickness. Further, the insulating sheath 2 may be damaged and the core 3 and the wires 3a, if any, may be exposed. However, the moulded casting 4 breaks in and seals against the insulating sheath and optionally the exposed core 3.

[0019] Now with reference to Fig. 2, in one embodiment of an electrical device 5 according to the present invention, the core 3 in the inner section of a length L2 along the electric cable 1 is relived from the insulating sheath 2 and the moulded casting 4 fills up the space around the core 3 and between the wires 3a, if any.

[0020] The moulded casting 4 is at least in an outer section of a length L3 and L4 of said seal joined to the insulating sheath 2. The assembly is preformed at an elevated temperature and this process may also be referred to as a confounding (melting) or welding between the insulating sheath and the moulded casting. The assembly is made possible through adequate material choices and methods of producing the electrical device 5. The moulded casting 4 and the insulating sheath 2 are polymer materials, including ordinary constructional plastics, but preferably thermoplastic elastic materials (TPE) are used for at least the moulded casting 4, although not excluding that e.g. nylon based polymer materials are used for both. The insulating sheath may include polyurethane, but of course other materials may be chosen such as the commonly used ordinary softened PVC and polyethylene. Further, high temperature insulating sheaths, including e.g. extrudable PTFE may be utilized. Thermoplastic urethanes (TPU), which is a sort of thermoplastic elastomeric material is one possible suitable thermoplastic elastomeric material for moulded casting 4 that is welded against the polyurethane insulating sheath 2. The core 13 is made of an electrical conductive material, usually a metal such as copper or a metal alloy.

[0021] Fig. 3 schematically illustrates an electrical device according to an embodiment of the present invention that includes at least one electrically conducting contact pin 6 extending from the electrical device 5, which contact pin 6 is connected to the electric cables 1 current carrying core 3 and partly included in the electrical device 5. In this embodiment the electrical device 5 constitutes a connector. The electric cable extends from the moulded casting in another direction than the contact pin 6. For connectors that are adapted to be utilized in electrical bushings, the electric cable preferably extends from the moulded casting from an opposite side with respect to the contact.

[0022] Each contact pin 6 includes a front part 7 constituting the part that extends outside the moulded casting 4, a centre part 8 that is arranged in the moulded casting 4 and a rear part 9, which is also arranged in the moulded casting 4 and that is connected to the electric cable 1. Said inner and outer damp barrier sections are arranged on a distance from the contact pin 6 along the electric cable 1.

[0023] Fig. 4 and 5 shows the centre part 8 of the contact pin 3. The centre part 8 preferably includes radial sections 10 that extend from the contact pin and are included in the moulded casting 4 and contributes to increased friction and stability between the contact pin 6 and the surrounding moulded casting 4 such that the handling of the contact part 5 is facilitated when the included parts are kept in place with respect to each other.

[0024] The attachment of the contact pins 6 inside the moulded casting 4 may be damp proof in that the moulded casting seals against the surface of the contact pins. Different types of contact pins may be utilized in the electrical device.

One alternative is a contact pin that is sealed at its front end and hence is damp proof in this part. Cheaper plate pins that are produced by folding of punched material often have an open slit along the pin and an opening in the front end. In particular, the types of contact pins that have a hole in the front end are advantageously filled. The filling may be provided in that the moulded casting is arranged around the contact pin and the corresponding electric cable. Thereby, the contact pin is filled with the same material as the moulded casting is produced from. The filling makes sure that open spaces in and around the contact pin are sealed and that a damp barrier is provided.

[0025] The rear part 9 of the contact pin 6 may include a centered recess 11 arranged along the longitudinal centre line C of the contact pin and the rear part 9 and/or the centre part 8 of the corresponding contact pin 6 may include radial openings 12 that penetrates into the centered recess 11. The moulded casting 4 is in close contact with each contact pin 6 and the electric cable 1 in correspondence to the contact pin 6. Each electric cable 1 is connected to the contact pin 6 in the end of the cable that has no insulating sheath 2 for a distance X, such that the core 3 is exposed. The exposed core 3 of the electric cable 1 is connected to the contact pin 6. The exposed core 3 is introduced into the recess 11 of the contact pin 6, e.g. as is shown as an example in Fig. 4. The core 3 may be exposed from the outer end and the nearest portion of it, outside the contact pin 6, i.e. for a sufficiently long distance to make sure that there is no insulating sheath 2 beyond the contact pin 6 for a distance Y, outside and behind the contact pin 6, which is schematically shown in Fig. 5. Upon arrangement, the moulded casting 4 breaks in and penetrates towards the core for the whole distance Y and seals against the core.

[0026] Fig. 6 schematically shows a moulded casting 4 that includes parts that are arranged in the radial openings 12 of the contact pin 6 and into the recess 11, towards/around the electric cable 1 and the core 3. Flowever, the core 3 of the electric cable is in contact with the contact pin for at least one point in order to enable current conduction from the core 3 to the contact pin 6.

[0027] The core 3 is arranged in the recess 11 of the contact pin 6 and may be attached to the contact pin 6 by means of any fastening device included in the contact pin 6 and/or the core 3, or by the contact pin 6 itself in such a manner that contact between the core 3 and the contact pin 6 is provided for.

[0028] Fig. 6 also shows two embodiments of an electrical device according to the invention which constitute connectors. In one embodiment the contact pin 6 is arranged on the electric cable 1 and a damp barrier has been provided in that the moulded casting is heated and clamped onto the electric cable 1 before it is arranged, such that the insulating sheath penetrates and seals against the core. Upon the arrangement of the moulded casting, e.g. by injection moulding the moulded casting also penetrates and fills the inside of the contact pin. In the second embodiment the electric cable runs through the casting and is optionally hanging freely from the side where the contact pin is located in the former embodiment. Damp barriers have thus been provided by removal of the insulating sheath 2 from the electric cable in a section of a length L2, and by heating and clamping the insulating sheath in another section of a length L2 before the moulded casting 4 is arranged. It is implicit that a damp barrier may be achieved with only one of these measures or by providing several peeled off or clamped sections. The mutual order along the electric cable may also be altered. From the drawings it is also evident that the electrical device may include several electric cables (strands) which all are damp proof according to the above.

[0029] As mentioned above the electrical device according to the present invention is suitable for electrical bushings through the housing to the enclosed electronics. In one embodiment the electrical device 5 includes one or several electric cables (strands) that extend right through a moulded casting 4. The electric cables 1 have damp barriers inside the moulded casting 4. The moulded casting is adapted to be arranged in an opening of a housing or a casing 14 with a seal 20 between the moulded casting and the housing or the casing 14. Fig. 7 schematically shows an example of an electrical device with the moulded casting adapted to be joined with a casing 14. Fig. 7 shows the electrical bushing in dismantled state, such that the seal 20 is visible. In one embodiment of the electrical device the casing 14 is joined to the moulded casting 4 at the seal in such a manner that the parts are melted or welded to each other under elevated temperature. In that occasion a thermoplastic elastic material may be included as a part of the seal, either as an added layer either on the moulded casting or on the casing, or either part is produced in such a material. Subsequently, the casing 14 may be joined to the remaining part of the housing in order to provide an electronic casing. This assembling may be provided by conventional methods or even with the utilization of thermoplastic elastic materials.

[0030] A method of producing of an electrical device 5 including an electric cable 1 with an electrically conducting core 3 enclosed by an insulating sheath 2 including: • arranging a moulded casting 4 around the electric cable 1 in a section of a length L1 and bringing it to seal against the insulating sheath 2 in at least a first outer section of a length L3,L4 along the electric cable 1; • bringing the moulded casting 4 or the insulating sheath 2 to penetrate and seal with respect to the electrically conducting core 3 in a inner section of a length L2 along the electric cable 1, wherein the electrical device 5 is damp proof along the electric cable 1.

[0031] In one embodiment, the method according to the present invention includes the steps of: • applying heat and pressure around the insulating sheath 2 in a inner section of a length L2 along the electric cable, wherein the insulating sheath 2 are brought to penetrate and seal with respect to the electrically conducting core 3; and subsequently • arranging of a moulded casting 4 around the electric cable 1 in a section of a length L1 along the electric cable 1 including the inner section, wherein the moulded casting is brought to seal against the insulating sheath 2 in a first and a second outer section of a length L3 and L4, respectively, along the electric cable 1, which said outer sections are arranged on each side of the inner section.

[0032] The insulating sheath 2 of the electric cables may be heated before and/or during the compression. The arrangement of the moulded casting under increased pressure and temperature may give a further compression of the insulating sheath 2 around the core 3.

[0033] In one embodiment of the present invention, the method includes the following steps: • removal of the insulating sheath 2 in an inner section of a length L2 along the electric cable 1 • arranging of a moulded casting 4 around the electric cable 1 in a section of a length L1, wherein the moulded casting 4 is brought to penetrate into the space around the core and between the wires 3, if any, and to seal against the insulating sheath 2 in a first and a second outer section of a length L3 and L4, respectively, along the electric cable 1, which said outer sections are arranged on each side of the inner section.

[0034] Further, the method of producing the electrical device may include the arranging of a contact pin 6 on one end of the electric cable 1, which is connected to the core 3 before the moulded casting is arranged around the electric cable 1 and a part of the contact pin.

[0035] In one embodiment of the method according to the invention, the pin is preferably filled with the same material as the moulded casting and in the same step as the moulded casting is arranged.

[0036] The exposing of the core implies that the wires 3a included in the exposed core 3 are exposed and that they are separated from each other, and that talc that may be provided there between is removed before the moulded casting 4 is arranged. The moulded casting 4 is heated upon the arrangement and is given such a temperature that the moulded casting 4 is joined to the insulating sheath 2 of the electric cable when it is already arranged against the insulating sheath 2. The elevated temperature provides for that the moulded casting is melted or welded to each other. The assembly is advantageously provided with a suitable bearing pressure, compressive force, that is totally or partly kept when the moulded casting 4 is cooling down. The heated moulded casting 4 may also be formed and given a suitable outer form upon the arrangement. Either the moulded casting 4 may be given a slim form that does not build on the electric cables outer shape more than necessary or they may be given a form that makes them easy to grip or fits to another formed part. The moulded casting 4 is formed by for example injection moulding, compression moulding, or blow moulding.

[0037] When the insulating sheath 2 is heated before and/or during compression it becomes softer and more flexible. The temperature is chosen sufficiently high in order for the material of the insulating sheath 2 to partly melt or soften and is then pressed in around the core 3 between the wires, if any, such that all possible air filled cavities in and around the core 3 are filled with the material of the insulating sheath. The force with which the electric cable 1 is pressed towards each other is chosen such that the housing 2 is pressed towards the core 3, but such that the core 3 is substantially unaffected by the force with respect to its shape which otherwise could imply that the electrical conductivity would be affected negatively (decreasing) e.g. by material collapse. This compressed section is advantageously placed on the electric cable 1 such the compressed section in the final contact part 5 is located inside the electrical device 5, inside the moulded casting 4. The section may alternatively be located outside, or there may be a further section is pressed, compressed and is provided with a distinct moulded casting 4.

[0038] However, the pressing, the compression, may result in damages in the electric cable 1, both in the insulating sheath 2 and the core 3, which is compensated by the moulded casting 4 that will come into contact with both the insulating sheath 2 and the core 3 and securely cover the core 3. The moulded casting 4, the body of the electrical device or parts thereof, is produced by a polymer material, a plastic mass, that is formed around the contact pin 6 and the electric cable 1. The moulded casting 4, which may be a polymer material, is pressed against each contact pin 6 and electric cable 1. The polymer material is pressed into the contact pin 6 via de radial openings 12 and further into the recess 11 and tightly against the electric cable 1 arranged therein.

[0039] The moulded casting 4, which e.g. is a polymer material, has such a material composition that, given the production temperature of the contact part 5, the plastic mass creeps into and around the corresponding contact pin 6 and electric cable 1. The plastic mass is pressed into and creeps into the radial openings 12 that lead into the centre recess 11 in which a core 3 of a cable is arranged and attached and thereby around the corresponding peeled off core 3 of the electric cable and also into and around the insulating sheath 2 of each electric cable. All possible cavities in and around the contact pin 3 and the electric cable 1 are filled with the moulded casting 4. Hence the moulded casting 4 is heated before and/or during the assembly, the forming/pressing, such that it becomes softer and more flexible, suitably to such a temperature that the moulded casting 4 melts together with the housing 2 of the electric cable. Due to this heating and compression, pressing, of the material that result in a substantial joining of the included plastic material and minimisation of the space between the different parts of the electrical devices moisture is prevented from entering the electrical device 5 and to the electrically conducting parts in the form of contact pin 6 and electric conductor 1, especially the core 3. Hence, the electrical device in the form of a connector 5 becomes watertight due to its construction.

[0040] The front end 7 of each contact pin 6 is such arranged during the production of the polymer material of the contact parts body and during the forming of the moulded casting 4, that it hangs freely outside the body of the contact part and thereby is not surrounded by the moulded casting 4, instead it remains arranged outside the electrical device 5 after the concluded forming.

[0041] The electric cables 1 are arranged next to each other in a suitable man- ner before or during the forming such that they end up on a practical and manoeuvrable location with respect to other parts of the contact part 5.

[0042] In one embodiment of the invention the method further includes the assembly of the moulded casting 4 against a casing 14. This may be exemplified by welding of an electrical device 5 according to Fig. 7 including a substantially plane surface of a moulded casting 4 from which a number of contact pins extend. The casing 14 includes a similar number of openings with corresponding distribution through which the contact pin are drawn. The plane surface of the moulded casting is thereby in this manner brought into contact with a plane surface on the casing, and by the application of pressure and heat to the moulded casting and the casing are joined by welding to form a seal. As mentioned above, both the moulded casting and the casing may be of any constructional plastic such as a polyamide material, but one or both parts or an intermediate layer may also include a thermoplastic elastic material.

[0043] The descriptions presented above of different embodiments of the invention shall not be seen as a limitation of the inventive scope, but shall instead constitute examples of ideas concerning the invention and inspiring use of the invention. Parts and details may in a suitable manner be combined with each other as long as the gist of the invention concerns the damp barrier function.

[0044] Even if the present invention has been described in terms of a connector having pins extending in one direction only, the skilled person realizes that the electrical device may include contact pins extending in two directions with an intermediate electric cable connecting these contact pins. The electric cable may also lack an insulating sheath at least on the part thereof that is partly enclosed inside and extends outside the moulded casting.

Claims (18)

An electrical apparatus (5) comprising an electrical cable (1) having an electrically conductive core (3) enclosed in an insulating sheath (2), characterized in that around the electrical cable (1) in a section with a length (L1) along the electrical cable, a molded part (4) is arranged, the molded part (4) joining close to the insulating sheath (2) in at least a first outer section with a length (L3) along the electric cable ( 1) and the molded portion (4) or insulating sheath (2) penetrates and connects tightly to the electrically conductive core (3) in an inner section of length (L2) along the electrical cable (1), whereby the apparatus ( 5) comprises a housing (14), wherein the molded part (4) of the electrical device (5) is connected to a sealing device (20) in the housing (14) so that the molded part (4) of the electrical device (5) forms a moisture-proof electrical feed piece from an outer side to an inner side of the housing (14). Electrical apparatus (5) according to claim 1, wherein the molded part (4) is welded to the housing (14). An electrical apparatus (5) according to claim 1 or 2, wherein the molded portion (4) joins tightly against the insulating sheath (2) in a second outer section of length (L4) along the electrical cable (1) and the first and second outer sections having a length of (L3) and (L4), respectively, are disposed on each side of the inner section having a length (L2). Electrical apparatus (5) according to claim 1, 2 or 3, wherein the electrically conductive core (3) comprises wires (3a) and the penetrating insulating sheath (2) or the molded part (4) at least within the interior section with a length (L2) substantially fills the space between the threads. Electrical apparatus (5) according to any one of the preceding claims, wherein the insulating sheath (2) in the inner section with a length (L2) along the electrical cable (1) is compressed in the direction of the core (3). Electrical apparatus (5) according to any one of claims 1 to 4, wherein the insulating sheath (2) is removed from the core (3) in the inner section by a length (L2) along the electrical cable (1). Electrical apparatus (5) according to any one of the preceding claims, wherein the molded part (4) is connected to, preferably welded to, the insulating sheath (2) in the outer section (L3, L4). Electrical apparatus (5) according to any one of the preceding claims, wherein the molded part (4) is of a polymeric material, preferably a thermoplastic elastomer (TPE), such as a thermoplastic urethane (TPU). Electrical apparatus (5) according to any one of the preceding claims, wherein the insulating jacket (2) is of a polymeric material such as polyurethane. An electrical appliance (5) according to any one of the preceding claims, further comprising at least one electrically conductive contact pin (6) or free cable end extending from the electrical appliance (5), said contact pin (6) or cable end is connected to the conductive core (3) and partially included in the electrical apparatus (5), whereby the electrical apparatus (5) is a plug connection. The electrical apparatus (5) of claim 10, wherein the molded portion (4) terminates tightly against the outer surface of the contact pin (6). The electrical apparatus (5) of claim 10 or 11, wherein the inside of the contact pin (6) is at least partially filled with a polymeric material. A method of manufacturing an electrical apparatus (5) comprising an electrical cable (1) having an electrically conductive core (3) enclosed in an insulating sheath (2), characterized in that a molded part (4) is arranged about the electrical cable (1) in a section with a length (L1) and caused to close tightly to the insulating sheath (2) within at least a first outer section of a length (L3, L4) along the electric cable (1), causing the insulating sheath (2) to penetrate and connect tightly to the electrically conductive core (3) within an inner section of length (L2) along the electrical cable (1) by heating and compressing the insulating sheath (2) before cast part (4) is placed around the electrical cable (1). The method of claim 13, wherein the insulating sheath (2) is removed within the inner section by a length (L2) before placing the molded part (4) around the electrical cable (1), thus bringing the molded part (4) to to penetrate and connect tightly to the electrically conductive core (3) within an inner section of length (L2). A method according to any one of claims 13 or 14, wherein the molded portion is heated and imparted at a temperature (4) upon application such that the molded portion (4) is welded to the electrical cable insulation cover (2). The method of any one of claims 13-15, wherein the placement of the molded portion (4) comprises injection molding. A method according to any one of claims 13 - 16, wherein a contact pin (6) is placed on one end of the electrical cable (1) and connected to the electrically conductive core (3) before the molded part is placed around the electric cable (1). and a portion of the contact pin (6). The method of claim 17, wherein the method comprises filling the contact pin (6).