EP0306913B1 - Coaxial cable-tapping connector - Google Patents

Description

The invention relates to a tap connector, for coaxial cable, capable of being mounted on a support of an equipment to be served or of an adjoining socket, both before and after connection to the coaxial cable and to ensure a connection in branching, possibly without intermediary, between the circuits of the equipment and the coaxial cable.

The growing use of coaxial cables for the interconnection of transmitting and / or receiving equipment, for example in the context of local networks with multiple stations, leads to the development of tapping conductors intended to connect the equipment in parallel along the same cable operated in a shared manner.

In many cases and in particular in that of networks with an evolving configuration, it is desired to preserve the integrity of the cables as much as possible and an effort is made to avoid the removable branch connections and T, which oblige to break up the cable and to provide it with end fittings for the fittings, as well as the fittings requiring a notching of the cable at the location of the stitching connectors to access the core.

Indeed in these two cases, the intervention made on the cable is irreversible and therefore most often annoying in the event of reconfiguration.

To avoid this drawback, tapping connectors are proposed where the branch connection is made by means of connection points penetrating transversely into the coaxial cable, through the protective sheath which covers it, in order to selectively become embedded in the external tubular conductor or in the central core.

The central connection point, commonly called a probe, is generally covered by an insulator at least in the part which is intended to penetrate the cable and with the exception of its end by which it is embedded in the core of the cable . This insulator is intended to eliminate the risks of short-circuiting of the cable by the probe, in particular when the external conductor is formed by a tubular braid of conductive wires.

To limit as much as possible the deterioration of the coaxial cables by the connection points, an effort is made to minimize the dimensions of the part of these points which penetrate the cable. A compromise must be made to allow the pins to resist the forces exerted on them when the connector is mounted on the cable and in particular when they penetrate the cable.

It is known to drill pilot holes in the cable at the locations provided for the connectors in order to facilitate the penetration of the probes to the core of the cable, this making it possible to limit the diameter of the probes accordingly.

Preferably, the pilot hole provided for a probe is made after the cable, where it is inserted, has been positioned and immobilized definitively in the connector and we take advantage of the conduit through which this probe is introduced and in which it stops, for the realization of this pilot hole. This solution makes it possible to take advantage of the drilling guide that is likely to form this conduit and to avoid the trial and error of setting up the probe that would be caused by drilling prior to immobilization of the cable in the connector.

It is also known to associate with the probe a spring device which presses its end against the core where it is encrusted, this is intended to ensure the consistency over time of the contact established between the probe and the soul.

The solutions mentioned above, which are used in particular in the context of the embodiment proposed by European patent 0109229, are also implemented by the embodiment described in the present application, one of the objectives of which is to provide a safe connector for tapping. and reliable, simple to manufacture and install, practically non-degrading for the cable.

Another objective of the present invention is also to propose a tapping connector capable of being positioned, on a support for an item of equipment to be served or an adjoining socket, both before and after connection to the coaxial cable.

The positioning of the probe, after pre-drilling of the cable involves mounting the connector on the cable prior to the fixing of this connector on its support and to its electrical connection to the equipment to be served or to the adjoining socket, when the probe is housed in the base by which the connector and is introduced through an orifice opening under this base, that is to say in the face of the latter which is normally applied against the support.

However, the obligation to assemble and connect a connector on a cable before it is assembled and connected to the user equipment has a certain drawback in various cases, for example when the equipment is provided with a fixed tapping connector intended to be connected to a coaxial cable only at the installation site, as is the case for many pieces of equipment sold in boxes without their external connection cables.

Consequently, the present invention provides a tapping connector, for coaxial cable, capable of being mounted on a support of equipment to be served or of an adjoining socket, both before and after connection to the coaxial cable and possibly ensuring a branch connection, without intermediary, between the electrical circuits of the equipment and the coaxial cable.

The tapping connector has two complementary parts which can be separated to allow the positioning of a coaxial cable passing through a through conduit, formed between the two parts, where this cable is immobilized when the two parts are fixed, tight against one the other. One of the parts, which serves as a base for fixing the connector to the support, carries external connection end pieces for connection points which protrude into the conduit, the end pieces themselves protruding outside under the face of support of the base. The connection points connect the ends respectively to the external tubular conductor and to the core from the outside of this cable. The connection point or probe, intended to be connected to the cable core, is removably mounted in a positioning guide which is arranged transversely to the cable conduit and which opens out on the one hand in this conduit and on the other hand out of the base.

According to a characteristic of the invention, the base is provided with a probe positioning guide which is oriented obliquely with respect to the support face of the base and which opens outwardly from the base above said support face and laterally with respect to the complementary part, which, associated with the base, immobilizes the cable this allowing the introduction and the withdrawal of the probe even when the connector is fixed on a support by its base.

The invention, its characteristics and its advantages are explained in the following description, in conjunction with the figures listed below.

Figure 1 shows a top view of a stitching connector according to the invention, positioned on a cable.

Figure 2 shows a left view of the connector of Figure 1, cable cut.

Figure 3 shows a front view of the connector of Figure 1, mounted on a support.

Figures 4 and 5 respectively show a cross section along IV-IV and a cross section along V-V of the connector of Figure 1, mounted on a support.

FIG. 6 shows a section along VI-VI of the two complementary immobilizing parts of the cable of the connector according to FIG. 1.

Figure 7 shows a probe and a cable drilling tool in connection with the connector as seen in Figure 4, here removed probe.

Figure 8 shows a partial sectional view of a connector variant presented here attached to a coaxial socket at a common support.

FIG. 9 shows an example of connection point fixing for the connector presented in FIG. 8.

The tapping connector shown in Figures 1 and 3 is intended to be mounted on a coaxial cable 1 with circular section to allow a branch to be made from this cable to user equipment, not shown.

To this end, the stitching connector is composed of two complementary parts, here made of insulating material, possibly metallized on the surface, between which is formed a conduit 4 allowing the passage of coaxial cable and its immobilization when the two complementary parts are fixed, tightened. 'one over the other.

One of the complementary parts forms a base 2 and makes it possible to place and fix the stitching connector on a support 5.

The other part forms a stirrup 3 allowing the immobilization of the cable to be connected.

In the proposed embodiment, this support 5 is a plate, for example an insulating plate carrying conductive tracks, not shown, produced according to known techniques for producing printed circuits, this plate possibly serving as a support for components for electronic mounting. .

The support face 2A of the base 2 on the support 5 is provided with external connection ends 6, 7, for connection points of the connection connector, to the coaxial cable 1.

These connection end pieces 6, 7 are here of the pin type so as to be able to be plugged into holes provided for this purpose in the support 5, for example in metallized holes making it possible, in a manner known per se, to connect by welding to the wave from the pins to the conductive tracks formed on the support 5.

Positioning pads 8 produced under the support face 2A of the base 2 on its support 5 slightly separate this support face 2A from the support 5 where it is posed and to which the connector is fixed, for example by conventional bolts, not shown, passing through the base 2 at its base and the support 5 by suitable holes such as 9 and 10 in FIG. 6.

In the embodiment presented, the cable conduit 4 - Figure 1 - is formed at the plane of the joints between complementary parts, that is to say between base 2 and bracket 3 and it extends parallel to the face support 2A and therefore support 5 when the stitching connector is fixed on this support. This therefore immobilizes the coaxial cable 1 parallel to the support 5, if necessary.

The cable duct 4 is here made of two half-ducts each formed by a through groove of semi-cylindrical appearance, hollowed out in one of the complementary parts. The half-duct formed in the base 2 extends longitudinally through the base 2, it is uncovered in the absence of the stirrup 3, which makes it possible to introduce the coaxial cable 1 which comes to lie therein. a well determined position because of its rigidity and its dimensional adequacy with this half-duct.

The stirrup 3 is placed on the base 2 so that the half-conduit which it comprises comes to fit on the corresponding half-conduit of this base by trapping the coaxial cable 1 which has been placed there. The stirrup of the stirrup on the base 2 is carried out here by means of bolts the arrangement of which is specified in FIG. 6.

Each bolt is conventionally composed of a screw 11 and a nut 12, the screw crosses in line the stirrup 3 and a part of the base 2 through conduits 13, 14.

The conduit 13 opens outside the connector, at the upper part of the bracket by an orifice of larger diameter than that which leads towards the bearing face of the base 2 through their common joint plane. The conduit 14 arises at the joint plane in the extension of the conduit 13 which it extends, it opens into a cavity 15 formed laterally in the base in the axis of said conduit 14 for a nut 12. This makes it possible to introduce the screws 11 through the upper part of the connector and the nuts 12 laterally in the base 2 whether the connector is fixed or not on its support.

FIGS. 4 and 5 make it possible to specify the internal structure of the connector in connection with the coaxial cable 1 which conventionally comprises a solid conductive core 1A situated at the center of a so-called external tubular conductor 1B from which it is separated by a solid insulator 1C. The external tubular conductor 1B, generally consisting of braided wires, is itself covered with an insulating and protective sheath 1D.

As indicated above, the support face 2A of the base is crossed by the connection end pieces 6, 7 of connection points 16 and of a probe 17 intended to come respectively into contact with the external tubular conductor 1B or the core 1A of the coaxial cable 1 through the latter and transversely with respect to it.

In the proposed embodiment, a pair of connection points 16 is arranged transversely to the immobilization conduit of the coaxial cable in the half-conduit formed at the joint plane between complementary parts in the base. The two connection points 16 of a pair are arranged symmetrically with respect to the median longitudinal plane of the half-duct, they enter this half-duct by two tapered parts intended to penetrate the external tubular conductor of the cable through the sheath and on either side of the soul.

The connection points 16 which are made of hard, good conductive material, are fixed by force fitting or by overmolding in the base 2 so that their second ends, for example forming pins, protrude through the bearing face 2A of this base to allow possible direct welding to the conductive tracks then carried by the support 5.

The insertion of a coaxial cable, on the connection points 16 in the conduit of a connector, is carried out during the installation of this cable in the half-conduit of the base 2, after prior removal of the caliper 3.

The replacement of the stirrup 3 on the base and the tightening of the bolts 11, 12 ensures the immobilization of the coaxial cable in the conduit 4 after penetration of the connection tips in the external tubular conductor 1B, the length of these tips and their spacing inevitably ensuring their penetration into the latter.

The immobilization of the coaxial cable 1 is also improved by the existence of flats 18, visible in FIG. 4, which oppose the movement of the cable both in rotation and in translation, after tightening the bolts securing the stirrup 3 to the base 2.

In the proposed embodiment and as seen in Figure 5, a single connection point or probe 17 is used for the connection of the tapping connector with the core 1A of the coaxial cable.

This probe 17 - Figure 7 - has a sharp point 17A intended to become embedded in the material of the core 1A, this sharp point made of conductive metal is conventionally embedded in an insulator intended to prevent it from contact with another conductor in its part likely to fit in a cable, with the exception of the sharp penetration end which it carries.

A thread 17B makes it possible to hold the probe in the base 2, the latter comprises for this purpose a probe positioning guide 20 which is arranged transversely to the cable duct and which is oriented obliquely with respect to the bearing face 2A of the base 2. The positioning guide 20 opens on the one hand into the duct 4, on the other hand out of the base 2 above the bearing face 2A and laterally with respect to the stirrup 3 which here covers the upper part of the connector, when in place. In the proposed embodiment, the positioning guide 20 opens obliquely flush with the upper part of the connection connector formed by the base 2 and the bracket 3 assembled, this makes it possible to introduce or remove the probe 17 that the connector either mounted or not on a coaxial cable 1 and / or on a support 5.

The positioning guide 20 also opens laterally into the conduit 4 where the coaxial cable is immobilized, outside the area covered by the stirrup 3.

The probe 17 is of the spring type and a coil spring 21 which it carries is housed in the positioning guide 20, around a cylindrical head made of insulating material 17C itself fixed at the end of the thread 17B, of the other side of the sharp point 17A of this probe.

The thread 17B is introduced into a slide 23 able to move in translation in a slide which ends the positioning guide 20 inside the stitching connector and which opens with a narrowed portion allowing the introduction of the sharp point 17A into the conduit 4.

The spring 21 comes to bear at one end on the slide 23, via a support washer 24, it also bears at its other end against a tubular stop 25 immobilized at the external mouth of the positioning guide 20, for example by a non-illustrated circlip engaging in a circular groove in the mouth of the guide or else by a key 26 fixed in the base. The cylindrical head 17C crosses the tubular stop 25 through which, it is able to move in rotation and partially in translation, a screwing imprint 27 is located at the end of the cylindrical body which is accessible from the outside through the tubular stop 25, it allows to screw and unscrew the probe.

A conductive element 28, constituted by a flexible wire or a braid, connects the slide 23 made of good conductive metal to the connection end piece 7 protruding from the bearing face 2A of the base 2.

This connection end piece 7 is here of hollow tubular type so as to allow introduction of the braid before fixing it by welding in the end piece. The latter is fixed to the end of a conduit 29 provided in the base between the internal end of the positioning guide 20 and the bearing face 2A for a conductive element.

The insertion of the probe into a coaxial cable 1, after immobilization of the latter between the base and the conductor stirrup, is carried out after perforation of the cable by means of a rotary drilling tool 30 carrying a projecting drill 30A on a 30B-30C drill holder.

The part of the drill 30A projecting from the drill holder 30B-30C is of length slightly less than the radius of a cross section of coaxial cable so as to penetrate into the solid insulation 1C of this cable through the protective sheath 1D and the external tubular conductor 1B without reaching the core 1A.

The drill 30A is provided for drilling a hole with the diameter of the sharp point 17A of the probe, it is introduced through the tubular stop 25, the spring 21 and the slide 23, the assembly formed by the tip 17A of the probe, the thread 17B and the cylindrical body 17C then being removed from the connector. The drill holder 30B-30C is here composed of two successive parts stepped in diameter, the part 30B which actually carries the drill has a diameter smaller than that of the thread produced in the slide 23 for the thread 17B, so as to allow free penetration and rotation of this part 30B in the thread when drilling the coaxial cable. The part 30C has a diameter corresponding to the internal diameter of the central hole formed in the tubular ring 25 for the cylindrical body 17C of the probe so as to use this central hole as a drilling guide.

The drilling is conventionally carried out by driving in and rotating the drill 30A by means of the tool body 30D until this body abuts against the tubular stop 25 and / or the base 2 outside the base 2.

After withdrawal of the drill bit from the tubular stop 25 the probe tip 17A-thread 17B-cylindrical body 17C assembly is introduced into the positioning guide 20 and the tubular stop 25.

The screwing of the probe tip 17A-thread 17B-cylindrical body 17C in the slide 23 is carried out by means of a screwdriver, not shown, applied in the screwing impression 27, it causes the slide to be pushed in. bottom of the positioning guide and that of the probe in the cable until its point 17 is embedded in the core 1A, after complete perforation of the solid insulation under the push of the screwdriver.

The support of the probe tip 17 on the core of the cable causes the slide 23 to rise along the thread 17B and the compression of the spring 21 between slide and tubular stop 25 and therefore the pressure constant of the tip on the core, in particular in the event of vibrations affecting the stitching connector.

Partial unscrewing of the probe-thread-cylindrical body assembly optionally allows the serviced equipment to be cut off from the circuit, when the probe tip separates from the core.

Disassembly of the connector by removing the probe, the bracket and the base leaves the coaxial cable practically intact.

The tapping connector according to the invention can also be mounted on a cable for subsequent connection of its probe, for example during commissioning. In this case the cable is positioned between the two complementary parts, the base possibly being already fixed on its support. The drilling of the coaxial cable for the passage of the probe is then carried out only when the latter is connected.

In a mounting variant, the stitching connector according to the invention, which has been described mounted on a plane support of equipment, for example of the printed circuit board type, is also capable of being attached to a male or female coaxial socket. usual to allow the connection of a coaxial bypass cable to the cable on which the tapping connector itself is mounted.

To this end, the base 2 ′ of the stitching connector, of which only the base is sketched in FIG. 8, is pressed against one face of a flat support 5 ′ here formed by a good conductive metal plate. The latter has holes 10 'aligned with the holes 9' of the base 2 'to allow attachment of the base on the support by screws, such as 31', or by screw and nut not shown. The support 5 ′ is also crossed by a hole 32 ′ intended to allow the passage of the connection end piece 7B ′ of the stitching connector. The connection end piece 7B ′, shown here in the form of a pin, is carried by a stud 7A ′ which comprises a passage duct for a conductive element 28 ′ connecting it electrically to the slide of the tapping connector. This passage duct is off-center with respect to the end piece 7B 'in the stud 7A' where it is crimped. The conductive element 28 'passes along the pin 7B' to lead to a central connection piece 33 ', female or as here male, of the coaxial socket. This connection piece 33 'comprises for example a conventional housing for one end of a conductive element 28' in which the latter can be welded, or possibly crimped.

A positioning bush 34 ', made of insulating material, surrounds the conductive element 28' between the base 2 'of the stitching connector and the central connection piece 33' which covers it. This positioning sleeve is immobilized by a sleeve 35 'intended to form the external cylindrical conductor of the coaxial socket, which is here assumed to be fitted with bayonets 36'. This external cylindrical conductor 35 'is for this purpose screwed concentrically to the central connection piece 33' on a fixing sleeve 37 'which is pressed against the base 2' by the support 5 '; this socket is immobilized concentrically with the connection end piece 7 ', for example by tightening an end flange 37A', which it comprises, in a circular groove bordering the hole of the support 5 ', through which said socket past.

The fixing sleeve 37 ′ and the external cylindrical conductor 35 ′ are preferably made of good conductive metal, as is the support 5 ′ in order to be able to serve as a ground connection, the support 5 ′ being connected to the connection pins 16 ′ of the connector stitching.

In the example presented, the connection points 16 ′ are plugged into the base 2 ′ and crimped at the end into the support 5 ′, as seen in FIG. 9.

A hollow cylindrical insulating filling 38 'is fixed for example by overmolding inside the end of the external cylindrical conductor 35' - Figure 8 - to come to be placed around the central connection piece 33 'which it surrounds and which 'it presses on the socket 34'. This filling maintains the central connection part and its central cavity allows the insertion of a central connection part, complementary to 33 ′, belonging to a complementary coaxial socket and here female, not shown.

Of course, it is possible to attach, in an identical manner, to a tapping connector, either a conventional male coaxial socket, or a conventional female coaxial socket for the purpose of connecting a coaxial cable or an appliance by complementary sockets not shown.

Claims (7)

1. An insulation-piercing connector for coaxial cables comprising two complementary members (2, 3) which are separable in order to allow the positioning of a coaxial cable (1) that traverses an open conduit (4) provided between the two members wherein said cable is immobilized when the members are fixed and tightened together, one (2) of said members serving as a fixing base member of the connector to the support (5) carrying outer connecting terminals (6, 7) for connecting spikes (16, 17) projecting into said conduit, and which connect the terminals from the outside of this cable respectively to the outer tubular conductor (1B) and to the core (1A) of the cable, said terminals projecting in turn from underneath the bearing surface (2) of the base member on the support towards the exterior, the connecting spike (17) or probe intended to be connected to the core being mounted in a removable manner in a positioning guide (20) of the base member, said guide being disposed transverse to the cable conduit (4) and opening out into said conduit, on the one hand, and out of the base member (2), on the other hand, characterized in that the probe positioning guide (20) is disposed obliquely to the bearing surface (2A) of the base member facing a support and opening above said bearing surface and laterally of the complementary member or bracket member (3), which, when associated with the base member, immobilizes the cable which allows for the introduction and the withdrawal of the probe, even when the connector is attached to a support by its base member.
2. An insulation-piercing connector according to claim 1, characterized in that said positioning guide (20) opens externally of said connector in the upper part thereof and laterally relative to the bracket member (3) which immobilizes the cable on said base member (2), that said bracket member covers the remainder of said upper part of the connector above said coaxial cable (1) relative to said base member (2), said bracket member being fixed to the base member (2) by means of immobilizing members (11, 12) on said upper part, so as to allow for putting into place and immobilizing the cable inside the connector, even when the base member of the connector is attached to a support.
3. An insulation-piercing connector according to claim 1, characterized in that the probe positioning guide (20) extends obliquely into the base member via a conduit, referred to as conducting conduit (29), which extends towards the bearing surface (2A) of the base member outside the cable immobilizing conduit (4), so as to allow for the electric connection of the probe (17) via a conducting element (28) with the corresponding external connecting terminal (7) which projects from underneath the bearing surface (2A) of the base member.
4. An insulation-piercing connector according to claim 1, characterized in that probe positioning guide (20) opens laterally into the cable immobilizing conduit (4) outside the area thereof covered by the bracket member (3) for immobilizing the cable.
5. An insulation-piercing connector according to claims 1 to 4, characterized in that it comprises a probe (17) capable of being screwed into a slider member (23) movable in translation a slide-way formed in the bottom of the positioning guide, said slider element being urged by a spring (21) towards the bottom of the slide-way, said spring bearing on said slider member (23) on the one hand, and on said tubular abutment member (25) on the other hand, with the slider member being immobilized within the positioning guide (20) above the spring towards the outside of the base member, said abutment member (25) being traversed by a cylindrical head (17C) of the probe which carries a screwing recess (27) at one end and which is surrounded by the spring (21), with the other end of the probe forming a conducting core connecting spike (17A) and projecting out of the slider member (23) into the conduit (4), when the probe is in place in its positioning guide (20).
6. An insulation-piercing connector according to claim 5, characterized in that the spike (17A) of the probe is electrically in contact with the corresponding outer connecting terminal (7) via the slider member (23) and with a conducting element (28) constituted of a flexible braid connected to the terminal and the slider member.
7. An insulation-piercing connector according to any of the preceding claims, characterized in that a coaxial plug or socket is linked to the base member to which it is fixed, with the terminals of the connector being electrically connected, respectively the ones of them to the external cylindrical conductor (35') of the plug or socket, the other to the center connecting member (33').

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