EP0008603B2 - Line coupler for connecting two electrical leads - Google Patents

Description

The invention relates to a cable coupling for connecting two electrical lines of the same number of wires, which consists of a socket containing contact sockets and a plug having plugs with a precise fit, in which the connection points between the conductors of the wires and the contact sockets or plug pins each tight are surrounded by a solid protective body sprayed around the connection points from an insulating material that can be welded firmly to the sheath of the lines, in which the plug has an annular component for sealing in the area of the fit, and in which means to avoid unintentional separation of the plug and socket are provided. Such a line coupling is apparent from US-PS-3 134 405.

Electrical couplings with connected lines have been known for a long time. They are required wherever electrical devices are to be connected to a voltage source. In particular, line couplings have become known, such as those used for so-called extension cords. As long as the devices, cables and couplings are used in a dry environment, there are generally no problems for the cable couplings.

On the other hand, most known couplings must not be used without further notice in a damp environment, but special designs are required for these areas of application. In particular, more and more electrical parts are used in motor vehicles, which are connected to the vehicle battery via lines. The engine compartment of motor vehicles is a damp room and, accordingly, high demands must be placed not only on the devices and lines, but also on the line couplings. For this special area, line couplings are used, for example, for devices for constant monitoring of the ignition and recently also for monitoring the brakes in so-called anti-lock braking systems. The accuracy of the sensors used here depends, among other things, on the fact that they are protected from moisture.

A line coupling is known which is to be used for an underwater connection and must therefore be moisture-tight. Both parts (socket, plug) of this cable coupling consist of several prefabricated elements that must be put together before a protective body can be pressed around the cable end. The plug and socket each consist of a rubber insert for holding plug pins or contact sockets, a sealing ring to ensure the required pressure resistance, an aluminum sleeve surrounding these parts and the protective body pressed around the cable end. A 0-ring and a sealing strip are also attached to the aluminum sleeve of the connector. This line coupling is therefore very complicated, ugl IEE Journal of Oceanic Engineering, Vol OE-3, No. 3, July 1978, pages 67-70.

Another, quickly releasable coupling is apparent from DE-OS-1 440 918. This known clutch should also be used as an electrical clutch. It then consists of two prefabricated coupling parts into which suitable electrical contacts are inserted. The same encompassing sleeve is used for fixed and non-rotatable, but releasable mounting of the two parts. In order to prevent rotation of the sleeve, one part of the coupling has outwardly projecting lugs which can engage in recesses in the sleeve. This known coupling is therefore also designed to be very complex.

DE-OS-2 802 798 shows an electrical plug connection, the line-side end of which is to be protected against environmental influences by an externally applied shrink tube.

A line coupling, as described at the beginning, is evident from US Pat. No. 3,124,405. The socket of this line coupling has a collar-shaped extension and a radially projecting flange. A circumferential recess is provided on the plug to accommodate the expansion of the socket. The cable coupling is held together by a two-part shell to be applied from the outside, the two parts of the shell being held together by a spring ring. This known line coupling is therefore complex and difficult to handle. The connection of the two coupling parts themselves is moisture-tight due to the complex structure. However, if moisture penetrates the connection point due to gross damage, it can penetrate along the wires or conductors of the connected lines and lead to faults at the far end of the lines.

The invention has for its object to provide a line coupling for connecting two electrical lines, which is easy to manufacture and handle, which allows a simple and quick connection of the two coupling parts, which further ensures that no moisture can penetrate into the interior of the coupling and with which it is ensured in particular that moisture cannot reach contacts which are located at the free end of the lines without a special encapsulation being required for the line coupling.

• a) die Dose weist eine topfförmige Erweiterung zur Aufnahme des in Form eines massiven, die mit den Leitern verbundenen Enden der Steckerstifte dicht umgebenden Stutzens verlängerten Steckers auf, wobei der Stutzen nach dem Zusammenstecken von Dose und Stecker von der Erweiterung umschlossen ist;
• b) das ringförmige Bauteil zum Abdichten ist als im Bereich des Stutzens angebrachter 0-Ring ausgebildet;
• c) der Stecker ist im Bereich des Stutzens mit mindestens zwei um 180° am Umfang gegeneinander versetzten Nasen ausgerüstet und die Dose weist im Bereich der Erweiterung Ausnehmungen zur Aufnahme der Nasen des Steckers auf;
• d) bei mindestens einem der Kupplungsteile Dose oder Stecker sind auf den über eine größere Länge als für die Verbindung mit den Kontaktbuchsen bzw. Steckerstiften erforderlich abisolierten Leitern mit deren Oberfläche verklebte, bis über die Isolierung der Leiter ragende Schrumpfschläuche derart angebracht, daß sie mit einem Ende unter Freilassung der Enden der Kontaktbuchsen bzw. Steckerstifte an den Leitern und mit dem anderen Ende an der Isolierung derselben jeweils flächenförmig dicht anliegen;
• e) die Schrumpfschläuche und die Adern sind durch Auftragen eines Haftvermittlers auf ihre Oberflächen vor der Anbringung des Schutzkörpers fest mit diesem verklebt.

This task is performed in a line coupling of the type described solved according to the invention by the combination of the following features:

• a) the socket has a pot-shaped extension to accommodate the extended in the form of a solid, the ends of the connector pins connected to the connector surrounding the connector, the connector being enclosed by the extension after plugging together the socket and connector;
• b) the annular component for sealing is designed as an O-ring attached in the area of the connecting piece;
• c) the plug is equipped in the area of the socket with at least two lugs offset by 180 ° on the circumference and the socket has recesses in the area of the extension for receiving the lugs of the plug;
• d) at least one of the coupling parts socket or plug are glued to the stripped conductors, which are stripped over a greater length than required for the connection with the contact sockets or plug pins, until the insulation of the conductors protrudes in such a way that they are attached with a End with the ends of the contact sockets or plug pins on the conductors and with the other end on the insulation of the same in each case tightly in contact;
• e) the heat shrink tubing and the wires are firmly glued to the surface of the protective body by applying an adhesion promoter to it before the protective body is attached.

The use of the O-ring on the extended socket of the connector creates a seal which ensures that the contacts of the socket and connector are protected against moisture, at least when the cable coupling is under normal load. The effectiveness of the O-ring is significantly improved in that the lugs are attached to the plug, which engage in recesses in the socket and thus provide additional locking.

In the event that moisture can penetrate into the line coupling, in particular as a result of gross damage, it is ensured that this moisture cannot spread along one line or both lines. Due to the glued-on shrink sleeves on the one hand and the glued or welded connection of the protective body to the surface of shrink sleeves, wires and cable sheaths on the other hand, the respective end of the cable - regardless of whether it is terminated by the socket or by the plug - is locked so that moisture cannot penetrate the corresponding line. The requirement for moisture-proof protection of the contacts located on the free line ends is ensured in a relatively simple manner without the line coupling itself being particularly encapsulated.

The special sealing with shrink sleeves and gluing is in principle only necessary for the coupling part, on the pipe of which a sensor to be protected against moisture is attached at the other end. The other coupling part can be designed without a special seal. However, if desired, both coupling parts can also be sealed in accordance with the invention.

An embodiment of the subject of the invention is shown in the drawings.

• Fig. 1 einen Schnitt durch eine Dose einer Leitungskupplung nach der Erfindung.
• Fig. 2 einen Schnitt durch einen dazu passenden Stecker.

Show it:

• Fig. 1 shows a section through a box of a line coupling according to the invention.
• Fig. 2 shows a section through a matching connector.

In the illustrated embodiment, both the socket and the plug are constructed to be fully sealed.

1 denotes a two-wire electrical line, the wires 2 and 3 of which are connected to contact sockets 4 and 5 of a socket of an electrical line coupling. The sheath of line 1 surrounding the two wires is designated 6 and consists of a suitable insulating material, for example of polyvinyl chloride or of polyurethane. A protective body 9 made of a suitable material is sprayed around the connection points between the conductors 7 and 8 of the two wires 2 and 3 and the contact sockets 4 and 5, this protective body also extending over the jacket 6 of the line 1. At the end facing away from the line 1, the protective body 9 is provided with a cup-shaped extension 10, which serves to receive a plug.

This plug is shown, for example, in FIG. 2 and has a protective body 11, which also encloses the end of a two-wire line 12. The two wires 13 and 14 of the line 12 are connected to connector pins 15 and 16, the protective body 11 also surrounding the connection points between the conductors 17 and 18 of the wires and the connector pins. The protective body 11 is provided with a nozzle 19, which represents an extension of the protective body 11, and which fits exactly into the opening of the extension 10 of the can. Furthermore, there is an O-ring 20 in the area of the socket 19. Two noses 21 and 22 are also attached to the socket 19 and engage in recesses 23 and 24 of the extension 10 when the plug is fully inserted into the socket. The jacket 25 of the line 12 can consist of the same material as the jacket 6 of the line 1.

The interaction of the O-ring 20, which lies close to the inner wall of the extension 10, and the lugs 21 and 22 which snap into the recesses 23 and 24 results in a line coupling which is protected against the ingress of moisture under normal conditions . Furthermore, the lugs fixed in the recesses prevent the coupling from opening unintentionally, as a result of which the electrical connection would be interrupted.

In the event that moisture has somehow penetrated the line coupling, the penetration of the moisture in the line direction is prevented by both the conductors themselves and the transition points being sealed by the conductors for their insulation and by the wires to the sheaths. This is achieved in that the wires 2 and 3 or 13 and 14 are stripped over a relatively long length. Shrinkable tubes 26 and 27 are drawn over the stripped conductors 7 and 8 or 17 and 18, which are provided with an adhesive layer on the inside. The shrink sleeves 26 and 27, which supplement the insulation of the conductors at the exposed locations, are shrunk onto the conductors. As a result, they stick to the conductor surface. The respective contacts can then be connected to the wires.

Before the protective bodies 9 and 11 are sprayed around the ends of the lines, an adhesion promoter is applied to the surfaces of the cores or the shrink tubes, through which a firm bond with the protective bodies 9 and 11 occurs during spraying. Furthermore, a material is used for the protective body, which can be firmly welded to the jackets 6 and 25 of the two lines 1 and 12. Accordingly, the protective bodies are preferably made of polyurethane.

If the conductors 7 and 8 or 17 and 18 are designed as stranded conductors, they are compressed into their core after stripping and before the application of the shrink sleeves 26 and 27. For this purpose, the conductor ends can be tinned, for example. The rest of the manufacture of the socket or plug is then the same as already described.

Claims (5)

1. Cable-coupling for the through-connection of two electric cables (1, 12) having the same number of conductors, this coupling consisting of a casing, containing contact sockets (4, 5), and of a plug, possessing plug-pins (15, 16), this plug having an accurate fitting shape, and the joints, in the casing and plug, between the cores (7, 8, 17,18) of the conductors (2, 3,13,14) and the contacts (4, 5, 15, 16), being surrounded in each case, in a leak-proof manner, by a solid protecting body (9, 11), made of an insulating material which can be securely welded to the jacket of the cables (1, 12) and is injection-moulded around the joints, in which coupling the plug possesses an annular component for effecting sealing in the region of the fitting shape, and in which means for avoiding unintentional separation of the plug and casing are provided, characterised by the combination of the following features:

a) the casing possesses a top-shaped widened portion (10) for receiving the plug, which is extended into the shape of a solid connecting piece (19), tightly sourroundig the plug-pins (15, 16), wherein the connecting piece (19) is enclosed by the widened portion (10) after putting together casing and plug;

b) the annular component for effecting sealing is designed as an O-ring (20) and is fitted in the region of the connecting piece (19);

c) the plug is equipped, in the region of the connecting piece (19), with at least two catches (21, 22), which are mutually displaced, on the periphery, by 180°, and the casing possesses, in the region of the widened portion (10), recesses (23, 24) for receiving the catches (21, 22) of the plug;

d) in at least one of the parts of the coupling, casing or plug, shrinkdown plastic tubes (26, 27) are fitted on to the cores (7, 8, 17, 18) and the insulation of the cores (7, 8, 17, 18), and are bonded to their surfaces after removing the insulation over a greater length than is necessary for the connection to the sockets (4, 5) and plug-pins (15, 16) in such a manner, that the shrinkdown plastic tubes (26, 27) tightly fit the surface of the cores (7, 8, 17, 18) at one end without projecting over the sockets (4, 5) and plug-pins (15,16) and at the oposite end over the insulation of the cores (7, 8, 17, 18);

e) before the protecting body (9, 11) is injection-moulded, secure bonding to the latter is assured by applying an adhesion-promotor to the surfaces of the shrinkdown plastic tubes (26, 27) and of the conductors (2, 3, 13, 14).

2. Cable-coupling according to Claim 1, characterised in that, when stranded wires are used for the conductors (2, 3, 13, 14), the cores (7, 8,17,18), from which the insulation has been stripped, are consolidated to form a compact unit, and in that the shrinkdown plastic tubes (26, 27) are fitted on the consolidated ends of the cores.

3. Cable-coupling according to Claim 2, characterised in that the consolidated ends of the cores (7,8,17,18) are tinned.

4. Cable-coupling according to one of Claims 1 to 3, characterised in that polyurethane is used as the material for the sheaths (6, 25) of the cables (1, 12) and for the protecting bodies (9, 11).

5. Cable-coupling according to one of Claims 1 to 3, characterised in that polyvinylchloride is used as the material for the sheaths (6, 25), and polyurethane is used as the material for the protecting bodies (9, 11).

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