EP0124131B1 - Extension piece for a coaxial cable core, and connector provided with such an extension piece - Google Patents

Description

The present invention relates to an extension of a core of a coaxial cable.

It also relates to a connector provided with such a core extender.

The coaxial cable cores consist either of a stretched tube, or either currently of a thin strip welded longitudinally. The core extenders of the prior art used in coaxial cables whose core consists of a stretched tube, are no longer suitable for cables currently manufactured whose core consists of a thin welded strip.

Such an extension device of the prior art is described in document US-A-2 822 418. This extension device consists of a cylindrical sleeve having, over part of its length, longitudinal slots delimiting fins, the other part being a closed end provided in its center with a tapped hole receiving a screw. This screw drives a conical ring which spreads the fins to clamp the sleeve against the core of two cables. But the head of this screw is only accessible from the inside and this requires that the extension is hollow to allow the passage of a screwdriver.

The present invention aims to allow the tightening of the screw from the outside, and thus authorize the connection of two very long cables or the use of all possible forms of recovery ends.

The subject of the present invention is an extension of a core of a coaxial cable, comprising a cylindrical sleeve provided with an end made flexible by longitudinal slots, a traction screw and a conical element for spreading the sleeve, characterized in that that it comprises a polygonal nut the edges of which are introduced into the longitudinal slots of the sleeve, the conical element being a cone forming part of the flexible end, this flexible end having an external diameter greater than the internal diameter of the core so that the introduction of the sleeve into the core tightens this flexible end and that the rotation of the traction screw, in abutment on the core, causes the translation of the nut which spreads and tightens the flexible end on the inner wall of the soul.

Advantageously, the nut is square, its four edges being each threaded into a longitudinal slot.

Preferably, one end of the traction screw is a cylindrical end guided in a bore of the sleeve.

The connector according to the invention, provided with a core extension of a cable comprising from the center towards its periphery, a central core, an insulating layer, an outer conductor and an outer insulating layer, is characterized in that the another end of the traction screw is a recovery end made up of two smooth shoulders.

Advantageously, this connector comprises a central tube threaded on the smooth shoulder of the recovery end.

• La figure 1 représente une vue éclatée du prolongateur.
• La figure 2 représente le prolongateur au cours de sa mise en place dans l'âme du câble coaxial.
• La figure 3 montre, en coupe suivant III de la figure 2, la forme particulière d'un écrou enfilé dans les fentes longitudinales de la douille du prolongateur.
• La figure 4 représente le prolongateur dans sa position de serrage.
• La figure 5 représente un connecteur d'un câble coaxial, muni d'un tel prolongateur d'âme.

It is described below by way of example and with reference to the figures of the appended drawing, an extender according to the invention and a connector provided with such an extender.

• Figure 1 shows an exploded view of the extender.
• Figure 2 shows the extension during its installation in the core of the coaxial cable.
• Figure 3 shows, in section along III of Figure 2, the particular shape of a nut threaded into the longitudinal slots of the sleeve of the extension.
• Figure 4 shows the extension in its clamping position.
• FIG. 5 represents a connector of a coaxial cable, provided with such a core extender.

In Figure 1, we see the core 21 of a coaxial cable and its inner wall 21 We also see, in exploded view, the extension 1 composed of a sleeve 2, a nut 10 and a screw tightening 12.

The sleeve 2 has two separate ends, a rigid end 8 with an outside diameter 3 provided with an internal bore 3 'and a bore with a larger diameter 7, a flexible end 4 provided with four fins 5 separated by four longitudinal slots 6 , better visible in Figure 3. These fins 5 are externally in a cylinder 9 connected to the outer diameter 3 of the rigid end 8 by a cone 9 '. The nut 10, better visible in FIG. 3, has four edges 11.

The traction screw 12 comprises a hexagonal clamping head 15, a threaded part 14, a cylindrical end 13 and a recovery end 16 composed of two cylindrical shoulders 17,18.

In FIG. 2, showing the positioning of the extender in the core of the cable, it can be seen that the rigid part 8 of the sleeve 2 is introduced inside the core 21, up to the level of the cone 9, and that the nut 10 previously screwed onto the end of the threaded part 14 of the traction screw 12 is introduced into the slots 6 of the sleeve until the latter comes into abutment on the rigid part 8.

In FIG. 3 in section along III in FIG. 2, it can be seen that the four edges 11 of the nut 10 are introduced into the longitudinal slots 6 of the sleeve 2.

In FIG. 4, showing the extender ready to be tightened in the core 20 of a cable, it can be seen that the sleeve 2 is inserted entirely in the core and that the fins 5, under the action of the cone 9 'are deformed and reduce the width of the slots 6.

The installation of the extension in the core of the cable is therefore carried out as follows:

The nut 10 is screwed onto the threaded end 14 of the traction screw 12 and then introduced into the socket, the socket-nut-traction screw assembly is then introduced into the core up to the level of the cone 9 'of the bushing, then by pinching them to the end of the fins 5. It is then sufficient to screw the traction screw and as soon as the latter is in abutment on the core 21, the nut slides in the tightened slots 6 and tightens the sleeve 2 on the wall 21 ′ of the core 21 by spacing the fins 5.

In Figure 5, showing the extension set up in a connector, we see this extension composed of the sleeve 2, the nut 10 and a traction screw 12 provided with a recovery end composed of two cylindrical shoulders 17, 18. This extension is engaged in the core 21 of a coaxial cable 20 which also includes an insulating layer 22 surrounding the core 21, then an undulating external conductor 23 covered by an external layer 24.

This connector 30 comprises a main socket 31 covering the end of the external layer 24 of the cable 20, another socket 34 screwed onto the socket 31 and bearing on the insulating layer 22 of the cable, a nut 40 immobilized in translation by a rod 60 permanently mounted in a groove 37 of the socket 34, a split piece 43 screwed into the socket 34 and comprising fins 43 ′, a tube 50 fitted on the shoulder 18 of the traction screw and comprising a nozzle 52.

An O-ring 62 is placed between the outer conductor 23 and the socket 31, and another O-ring 33 seals between the sockets 31 and 34. A metal rod 65 plates the end of the outer conductor 23 on a cone 36 of the socket 34 tightened by means of a key engaged in the notches 35.

A washer 61 surrounds the clamping head 15, and an insulating layer 44, for example made of polytetrafluoroethylene or polythene, covers the shoulder 17 of the traction screw and the tube 50 up to its end 52.

The end piece 52 and the fins 43 ′ engage in a standardized connection socket (and not shown), while the nut 40 is screwed onto this socket. The seal between the connector 30 and this socket is ensured by a seal 42 placed in a groove 38 of the socket 34.

Without departing from the scope of the invention, this extender can be used in all types of coaxial cable connectors or serve to connect the cores of two coaxial cables, by transforming the recovery end of the traction screw into an equivalent threaded rod to the threaded part of the screw but of reverse pitch, and by adding another nut and another socket in the core of the second cable.

Claims (5)

1. Extension (1) of the core (21 ) of a coaxial cable (20), comprising a cylindrical socket (2) supplied with an end (4) made flexible by means of longitudinal slots (6), a traction screw (12) and a conical element for spreading the socket, characterized in that it comprises a polygonal nut (10), the edges (11) of which are introduced into the longitudinal slots (6) of the socket (2), the conical element being a cone (9') which is part of the flexible end (4), this end having an outer diameter which is greater than the inner diameter of the core so that the introduction of the socket into the core tightens this flexible end and that the rotation of the traction screw (12), when applied against the core (21), provokes the translation of the nut (10) which spreads and tightens the flexible end on the inner wall (21') of the core (21).

2. A core extension of a coaxial cable according to claim 1, characterized in that the nut (10) is square, its four edges (11) being each slipped into a longitudinal slot (6).

3. A core extension of a coaxial cable according to one of claims 1 to 2, characterized in that one end of the traction screw (12) is a cylindrical end (13) which is quided in a bore (3') of the socket (2).

4. A connector (30) equipped with a core extension (1) of a cable according to one of claims 1 to 3, the cable comprising from its center outwards a central core (21), an insulating layer(22), an outer conductor (23) and an outer insulating layer (24), characterized in that the other end of the traction screw (12) is a pick-up end (16) constituted by two smooth shoulders (17,18).

5. A connector according to claim 4, characterized in that it includes a central tube (50) which is slipped on the smooth shoulder (18) of the pick-up end.

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