EP3243243B1

EP3243243B1 - Cable connector assembly with releasable connectors

Info

Publication number: EP3243243B1
Application number: EP15706056.7A
Authority: EP
Inventors: Phil KENNEY; Darren Michael Spiller
Original assignee: Prysmian SpA
Current assignee: Prysmian SpA
Priority date: 2015-01-09
Filing date: 2015-01-09
Publication date: 2022-05-04
Anticipated expiration: 2035-01-09
Also published as: WO2016110748A1; EP3243243A1; ES2916207T3

Description

BACKGROUND

The invention relates to a provision to join electric power cables, in particular power cables that are installed in the signaling power infrastructure of railroad systems or tunnels. The cables have a typical conductor cross section between 16 mm² and 400 mm².
In these infrastructures the joints between the cables are traditionally made in situ. In this process the aluminium or copper conductors are mounted to each other by means of either soldering, crimping or by means of a bolted connection, and subsequently enclosed in a housing. The housing is finally filled with a hardening resin to provide the insulation and to prevent ingress of water. Another solution is to enclose the connection in a heat shrinkable enclosure. When the cables are reconfigured, the cables are cut off and the joints are disposed.
The cables of a signaling power infrastructure are installed in public areas or easily accessible areas. Due to the copper conductors the cables are vulnerable to theft. Therefore the cables more and more comprise conductors of aluminium instead of copper. Aluminium cannot be soldered in situ as easily as copper and there are known issues with corrosion if aluminium conductors are not prepared correctly when used in a crimp or bolted connection. Therefore there is a need for an alternative joint.
It is noted that CN 101 841 113 A and GB 2 343 302 are known background art.
It is an object of the present invention to provide provisions to join electric power cables, in which the joint is releasable and reusable.
It is an object of the present invention to provide provisions to join electric power cables with copper and/or aluminium conductors.

SUMMARY OF THE INVENTION

The invention provides a cable connector assembly according to claim 1, the cable connector assembly comprising two electric power cables with multiple insulated electric conductors and a connector assembly that forms a releasable joint between the ends of the electric power cables, wherein the cable connector assembly comprises two end connectors on the meeting ends of the power cables, an intermediate connector between the end connectors, and a housing that receives the connectors, wherein the end connectors each comprise a first coupling and a grommet, wherein the first coupling comprises metal contacts that are attached to the electric conductors of the cable and the grommet extends around the attached end of the cable, and wherein the intermediate connector comprises two second couplings with electrically conducting contacts, wherein a first coupling and a second coupling together form an interlocking pair in which the contacts are electrically connected and sealed off, while the first couplings prevent mutual interlocking, wherein the end connectors are aligned with the first couplings towards the second couplings of the intermediate connector and the housing surrounds at least the interlocking couplings.
The assembly according to the invention comprises end connectors that can be factory installed on the ends of the power cables. The first couplings and second coupling seal off the contacts, making it watertight. This allows the use of aluminium conductors, reducing the risk of corrosion due to badly prepared conductors as the connectors can be fitted in a controlled factory environment. The end connectors do not mate to each other but can only be interconnected by means of the intermediate connector, thus preventing installation errors. The end connectors are coupled mechanically to the intermediate connector and are finally enclosed by the housing to form the joint. This joint is releasable by releasing the housing and disconnecting one of the end connectors.
In the embodiment according to the invention, the first coupling and the second coupling each comprise an insulating sleeve along and around each of their contacts, wherein the sleeves of the interconnecting couplings tightly slide into each other and enclose the contacts. The engaging insulating sleeves prevent the ingress of water along the contacts, whereby electrical failure and corrosion of the contact is prevented.
In an embodiment the first coupling and the second coupling comprise a key body or a mating receiving space for the key body at one side of its contacts. The mating key body and receiving space ensure that the first coupling and the second coupling are interlocked in only one way regarding the contacts. In this manner it is possible to consistently continue the individual electric conductors, whereby it remains known whether it is a neutral conductor or a phase conductor, for example.
In a combined embodiment the key body is integral with or adjacent to the insulating sleeves.
In an embodiment at least one of the first coupling and the second coupling comprises an insulating shield that extends spaced apart and around the entirely of the sleeves to form an additional barrier for water.
In an embodiment thereof the other of the first coupling and the second coupling comprises a flexible seal lip that tightly engages the shield along the circumference of the first coupling and second coupling.
In an embodiment the first coupling and the second coupling comprise a shape retaining, flexible body in which its contacts are enclosed. The flexible bodies can provide a releasable press fit between the engaging parts that is still releasable.
In an embodiment thereof the flexible bodies are a mold of a thermoplastic polymer or copolymer, elastomer or a thermoplastic elastomer.
Preferably the flexible bodies are a mold comprising an elastomer, such as natural rubber or a thermoplastic elastomer, such as styrene-butadiene rubber (SBR) or ethylene propylene diene monomer (EPDM) rubber. These provides good insulation, durability, sealing and vibration and impact resistance to the connectors.
In an embodiment the second couplings of the intermediate connector are positioned back to back, wherein the contacts are continuous from one coupling to the other. This intermediate connector forms a compact unity that is easily handled.
In an embodiment the contacts of the first coupling and second coupling each have one of a mating pin and socket.
In an embodiment thereof the pins or sockets of the end connectors are electrically connected to the electric conductors of the cables.
In an embodiment the cable connector assembly comprises an electrically insulating end cap at the distal end of the pin, whereby the pin itself cannot be reached from outside. This allows the handling and joining of the power cables when they are already live or powered.
In an embodiment the contacts of the first coupling comprise a crimp connector around the end of the attached electric conductor. A crimp connector can be attached mechanically to electric conductors of any kind of metal, such as copper and aluminium.
In an embodiment the material of the crimp connector differs from the material of the pin or socket, making the contacts bimetallic. The materials for the crimp connector and the pin or socket can be optimized to their specific function. The parts may be joined together to one unity by welding or melting.
In an embodiment the pins or sockets are of copper or an alloy comprising copper, such as brass.
In an embodiment the pins or sockets are of tinned or silver plated copper or an alloy thereof, such as brass.
In an embodiment the cables comprise aluminium electric conductors, which makes them less vulnerable to theft.
In an embodiment the crimp connector is mainly of aluminium or an alloy comprising aluminium, for example an alloy of aluminium and copper.
In an embodiment the crimp connector is mainly of copper or an alloy comprising copper, such as brass.
In an embodiment the end connectors and the intermediate connector have in cross section a circumference that is partly circular at the outside of the outer contacts and flat there between. When more than two electric conductors are present, the attached contacts may extend in the same plane.
In the embodiment according to the invention the housing comprises multiple shells that together surround the interlocking coupling, wherein each of the shells comprises an outer groove formed by a rim above the end connectors to receive a metal or plastic tightening strip that keep the shells firmly against each other. This housing can easily be assembled in situ.
In an embodiment the end connectors each comprise a gripping groove at its outer side to provide sufficient grip to push the couplings into each other.
In an embodiment the housing comprise an engaging portion with a rim that engages the gripping groove to lock the interlocking couplings.
In an embodiment the cable connector assembly comprises a tool that is configured to engage an end connector and to move it towards the intermediate connector. The tool facilitates the interlocking of the couplings and may provide more pushing force than delivered by hand.
In an embodiment the tool comprises an engaging portion with a rim that engages the gripping groove.
In an embodiment the electric power cables comprise an individual insulation around each electric conductor.
In an embodiment the electrical power cables comprise an individual insulation, wherein the insulations collectively define a circular outer circumference.
In an embodiment the cables comprise a round sheath around the bundle individually insulated electric conductors.
In an embodiment the electric conductors are stranded conductors to provide sufficient flexibility to install the cables in small gutters.
In an embodiment the electric conductors have an individual conductor cross section between 16 mm² and 400 mm².
The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings, in which:

Figures 1A, 1B and 1C are an isometric view, a longitudinal section and a detail of a cable connector assembly according to a first embodiment of the invention, in connected state;
Figures 2A and 2B the views of the cable connector assembly according to figures 1A and 1B, before connecting;
Figures 3A and 3B an isometric view of the cable connector assembly according figure 1A, together with a connecting tool; and
Figure 4 an isometric view of a cable connector assembly according to a second embodiment of the invention, before connecting.

DETAILED DESCRIPTION OF THE INVENTION

Figures 1A, 1B and 1C are an isometric view, a longitudinal section and a detail of a cable connector assembly 1 according to a first embodiment of the invention, in connected state. Figures 2A and 2B show the assembly 1 before connecting.
The cable connector assembly 1 is configured to form series of joined power cables 10 having at least two electric conductors 11, 12, typically made from aluminium or copper, each with a conductor cross section typically between 16 mm² and 400 mm². These power cables 10 are typically used in the signalling power infrastructure of railroad systems, wherein an earth conductor in the power cables 10 is not necessary. The conductors 11, 12 are individually enclosed by a flexible plastic insulation 13, 14 with unique colours to identify the conductors 11, 12, such as the neutral and the phase, or two phases. In this embodiment the insulations 13, 14 together define a circular outer side and are enclosed in a flexible sheath 15. The sheath 15 is typically elastomer or silicon based. In this embodiment the conductors 11, 12 have a semicircular cross section. Typically, the conductors 11, 12 are stranded for conductor cross sections larger than 120 mm² to provide sufficient flexibility for the cables 10. The flexibility is necessary to be able to configure the cables 10 in small gutters that extend along and across railroad tracks. The power cables 10 may have an alternative geometry in cross section. The conductors may have any other cross section, such as circular. The insulated conductors may together form a (twisted) bundle or be located in the same plane.
The cable connector assembly 1 comprises two identical end connectors 20 at the ends of the power cables 10. The end connectors 20 are installed in a controlled factory environment instead of on site to ensure the quality of the final joint. Each end connector 20 comprises a grommet 50 and a socket 40 or first coupling that forms one molded unity, or, as shown in figure 2B, may be mechanically united by means of a tongue and groove connection 52. The grommet 50 is provided with a gripping groove 51 that extends around the circumference to connect a housing and a tool as described hereafter. The socket 40 and the grommet 50 are typically moulded parts of a thermoplastic polymer or copolymer, elastomer or a thermoplastic elastomer to provide a shape retaining socket having some flexibility. Suitable materials are typically natural rubber or a thermoplastic elastomer such as styrene-butadiene rubber (SBR) or ethylene propylene diene monomer (EPDM) rubber. These provide good insulation, durability, sealing, and vibration and impact resistance to the end connectors 20.
The socket 40 comprises a base 41, and two parallel inner sleeves 42 and an outer shield 43 extending from the base 41. The sleeves 42 extend spaced apart from each other. The shield 43 extends spaced apart from the two sleeves 42 over the same intermediate distance to provide an insertion space 44 having a constant width at the outer curved sections and at one side of the pair of sleeves 42 only to form a key body 48. The free ends of the sleeves 42 and the shield 43 define a straight front face A. The sleeves 42 have an insert opening 46 at the front face A and the shield 43 comprises a convex circumferential sealing groove 45 adjacent to the front face A.
The first connectors 20 are each provided with a bimetallic socket assembly 21, 22 or contact for each conductor 11, 12. The socket assemblies 21, 22 each comprise a bushing 25 and a wider mounting base 28 of tinned or silver plated copper. In the bushing 25 an insert channel 26 is present, in which an additional coil spring 27 may be enclosed for optimal electric contact. The mounting base 28 is provided with a circumferential groove 29. The socket assemblies 21, 22 are tightly enclosed in the sleeves 42 to debouch behind the smaller insert opening 46 of the sleeves 42. The enclosure is locked by a tongue 47 of the base 41 in the groove 29, which tongue 47 is formed when the socket 40 is molded around the socket assemblies 21, 22. The socket assemblies 21, 22 furthermore comprise an aluminium joint 30 having a crimp connector 31 that is crimped tightly around the aluminium conductors 21, 22 while maintaining the typical semicircular cross section thereof. The aluminium joints 30 and the peeled ends of the cables 10 are fully enclosed by the grommet 50.
The two end connectors 20 are in direction B only connectable to an intermediate connector 60, not to themselves. The intermediate connector 60 comprises a pin housing 61, which is a moulded part of a thermoplastic polymer or copolymer, elastomer or a thermoplastic elastomer to provide a shape retaining pin housing having some flexibility. Suitable materials are typically natural rubber or a thermoplastic elastomer such as styrene-butadiene rubber (SBR) or ethylene propylene diene monomer (EPDM) rubber. These provide good insulation, durability, sealing, and vibration and impact resistance to the intermediate connector 60.
The pin housing 61 comprises a base 62 and two second couplings with among others two pairs of sleeves 63 extending parallel and opposite from each other from the base 62. Only at one side of each pair of sleeves 63 a key body 67 is formed between the sleeves 63. The sleeves 63 are aligned with the sleeves 42 of the sockets 40 and receive and enclose them tightly under slight local elastic deformation or impression. The pin housing 61 comprises two circumferential sealing lips 64 that define insertion spaces 65 for the shields 43 of the sockets 40, wherein the sealing lips 64 engage the sealing grooves 45 in a self-locking manner. As shown in figure 1C, the pin housing 61 comprises two circumferential grooves 49 that extend opposite to the sealing lips 64. In the grooves 49 a flexible O-ring is locked that is not shown. The sealing lips 64 and the O-rings together tightly confine the inserted shields 43. The pin housing 61 furthermore comprises a gripping groove 66 that extends around the circumference to connect a housing or tool as described hereafter.
The intermediate connector 60 comprises two pin assemblies 70, 71 each comprising a mounting base 72 and two oppositely extending pins 73 that are all of tinned or silver plated brass or copper, and two plastic end caps 74. The free ends of the sleeves 63 and the end caps 74 define a straight front face C on both sides that is free of tangible electrical parts. The mutual engagement of the sleeves 42, 63, and the engagement of the shield 43 ensure that the socket assemblies 21, 22 and the pin assemblies 70, 71 are sealed off watertight.
The end connectors 20 can only connect to the intermediate connector 60 when the key bodies 48, 67 are opposite to their mating receiving space of the opposite connector 20, 60. The key bodies 67 of the intermediate connector 60 itself are located mirror-symmetrically. In this way it is ensured that the same conductors 11, 12 are continued in the right manner only. One cable 10 with two end connectors 20 forms one prefabricated unity, which can interconnect in series by using intermediate connectors 60 in between. In such series the unique conductors 11, 12 remain distinguishable.
The cable connector assembly 1 comprises a housing 80 having two mating shells 81, 82 of a rigid material that could be metallic or plastic. The shells 81, 82 each comprise a central portion 83 that receive the intermediate connector 60, and two end portions 85 that receive the majority of the end connectors 20. The shells 81, 82 are provided with inner rims 84, 86 that engage the gripping grooves 66, 51 of the intermediate connector 60 and the end connectors 20, respectively. The shells 81, 82 furthermore comprise two outer grooves 87 formed by rims above the end connectors 20 to receive a metal or plastic tightening strip 88 that keep the shells 81, 82 firmly against each other.
Figure 3 schematically shows a connecting tool 90 to connect the connectors 20, 60 to each other. The tool 90 comprises a first clamp 91 and a second clamp 92 that are linearly movable to each other by means of guides 93 and a lever 94. The closing clamps 91 engage the intermediate connector 60 and one end connector 20 at the gripping grooves 66, 51 after the intermediate connector 60 has been loosely placed in front of it, and press the connectors 20, 60 firmly against each other by swinging the lever 94.
Figure 4 shows a connector assembly 101 according to a second embodiment of the invention. The features that correspond with the first embodiment are provided with corresponding reference numbers. Only the additional features are described hereafter.
The connector assembly 101 comprises an intermediate connector 160 that is additionally provided with a branch socket 110 or coupling having metal contacts that are electrically connected with the pin assemblies 70. The upper shell 81 has been provided with an opening for the branch socket 110. The branch socket 110 is configured to receive a branch plug 111 at the end of a branch cable 112.
It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention as defined in the appended claims.

Claims

Cable connector assembly (1) comprising two electric power cables (10) with multiple insulated electric conductors (11, 12) and a connector assembly that forms a releasable joint between the ends of the electric power cables (10), wherein the cable connector assembly (1) comprises two end connectors (20) on the meeting ends of the power cables (10), and an intermediate connector (60) between the end connectors (20), wherein the end connectors (20) each comprise a first coupling (40) and a grommet (50), wherein the first coupling (40) comprises metal contacts (21, 22) that are attached to the electric conductors (11, 12) of the cable (10) and the grommet (50) extends around the attached end of the cable (10), and wherein the intermediate connector (60) comprises two second couplings with electrically conducting contacts (70, 71), wherein a first coupling (40) and a second coupling together form an interlocking pair in which the contacts (21, 22; 70, 71) are electrically connected and sealed off, wherein the first coupling (40) and the second coupling each comprise an insulating sleeve (42; 63) along and around each of their contacts (21, 22; 70, 71), wherein the sleeves (42; 63) of the interconnecting couplings tightly slide into each other and enclose the contacts (21, 22; 70, 71), while the first couplings (40) prevent mutual interlocking, wherein the end connectors (20) are aligned with the first couplings (40) towards the second couplings of the intermediate connector (60), characterized in that the cable connector assembly (1) comprises a housing (80) that receives the connectors (20), and that the housing (80) surrounds at least the interlocking couplings, wherein the housing (80) comprises multiple shells (81, 82) that together surround the interlocking couplings, wherein each of the shells (81, 82) comprises an outer groove (87) formed by a rim above the end connectors (20) to receive a metal or plastic tightening strip (88) that keep the shells (81, 82) firmly against each other.
Cable connector assembly (1) according to any one of the preceding claims, wherein the first coupling (40) and the second coupling comprise a key body (48; 67) or a mating receiving space for the key body (48; 67) at one side of its contacts (21, 22; 70, 71).
Cable connector assembly (1) according to claims 1 and 2, wherein the key body (48; 67) is integral with or adjacent to the insulating sleeves (42; 63).
Cable connector assembly (1) according to any one of the preceding claims, wherein at least one of the first coupling (40) and the second coupling comprises an insulating shield (43) that extends spaced apart and around the entirely of the sleeves (42; 63), wherein the other of the first coupling (40) and the second coupling preferably comprises a flexible seal lip (64) that tightly engages the shield (43) along the circumference of the first coupling (40) and second coupling.
Cable connector assembly (1) according to any one of the preceding claims, wherein the first coupling (40) and the second coupling comprise a shape retaining, flexible body (61) in which its contacts (21, 22; 70, 71) are enclosed.
Cable connector assembly (1) according to claim 5, wherein the flexible bodies (61) are a mold of a thermoplastic polymer or copolymer, elastomer or a thermoplastic elastomer.
Cable connector assembly (1) according to any one of the preceding claims, wherein the second couplings of the intermediate connector (60) are positioned back to back, wherein the contacts (70, 71) are continuous from one coupling to the other.
Cable connector assembly (1) according to any one of the preceding claims, wherein the contacts (21, 22; 70, 71) of the first coupling and second coupling each have one of a mating pin and socket (25; 73), wherein the cable connector assembly (1) preferably comprises an electrically insulating end cap (74) at the distal end of the pin (73).
Cable connector assembly (1) according to any one of the preceding claims, wherein the contacts (21, 22) of the first coupling (20) comprise a crimp connector (31) around the end of the attached electric conductor (21, 22).
Cable connector assembly (1) according to claims 8 and 9, wherein the material of the crimp connector (31) differs from the material of the pin or socket.
Cable connector assembly (1) according to any one of the preceding claims, wherein each of the end connectors (20) and the intermediate connector (60) comprise a gripping groove (51; 66) at its outer side, wherein the housing (80) preferably comprises an engaging portion with rims (84, 86) that engage the gripping grooves (51; 66) .
Cable connector assembly (1) according to any one of the preceding claims, wherein the intermediate connector (60) comprises a third coupling (110) with metal contacts that electrically branches off from the contacts of the second couplings, wherein the housing (80) preferably comprises a side aperture that is located between the second couplings, wherein the third coupling is located in or accessible via the aperture.
Cable connector assembly (1) according to any one of the preceding claims, wherein the electric conductors (11, 12) have an individual conductor cross section between 16 mm² and 400 mm².