EP0902501B1 - Connection module for telecommunications cable and terminal element incorporating the same - Google Patents

Description

The invention relates to a module for connecting the wires of a cable. telecommunications to a terminal device, for example an adapter or a socket, for the transmission of communication signals for the benefit of a communicating device to which the organ is at least temporarily affected.

More specifically, it relates to a module where the connection of the wires is carried out by means of so-called insulation displacement contacts. It also concerns the terminal members for cables which include such a module.

The use of insulation displacement contacts to connect electrical wires individually insulated and in particular telecommunications cable wires is a proven connection technique. Each contact consists of a conductive metal part with at least one slot, one end of which open is shaped so as to allow the insertion of the core of a wire electric transversely in the slot by pressure and partial elimination insulating sheath covering this wire. The sinking of this soul in this slit entails its immobilization by pinching and an electrical connection of the soul with the room. The part constituting the contact is electrically connected to a other conductive element of the member which comprises it with a view to serving the communicating device to which the organ is assigned, this other element is by example another conductive part, such as a connecting bar, of the member or a track on a printed circuit on which the part is mounted.

As is known, there is a strong incentive for the miniaturization of connection modules insofar as the communicating devices to which they are likely to be affected tend to miniaturize themselves, when possible.

However, the miniaturization of connection modules for cables communication involves solving some type problems intended for such cables. Indeed the communication cables allow digital signals to be transmitted at high bit rates, example of the order of 150 megabit / s and it is necessary that their recovery after transmission can be carried out in good conditions as required by the relevant standards.

In addition, telecommunications cables are most often intended for allow to establish several communication circuits and therefore several simultaneous transmissions between their two respective ends, the same circuit usually using at least one pair composed of two twisted wires of the cable or possibly a fourth corresponding to two pairs of wires twisted.

There is then a real risk of disruption of transmissions due to crosstalk, in particular at the level of a connection module where the wires of a cable operated in this way. This therefore leads the designers of connection modules to take precautions when positioning the insulation displacement contacts of a module with respect to each other and to provide recommendations for positioning the wires of the pairs or possibly a quarter of a telecommunication cable compared to insulation displacement contacts of the connection module to which they come respectively connect.

The document EP-A-700126 describes an example of a connection module for cable which is shown incorporated in a plug-type member comprising a standardized RJ45 interface module for connecting this unit to a communicating device not shown.

The document EP-A-782 221 describes a connection module according to the preamble of claim 1.

The invention provides a miniature connection module for telecommunications, having improved transmission characteristics and more specifically a connection module comprising contacts identical insulation displacement insulators with wire holding slot (s), said slots being with wire insertion mouths opening on the same side with respect to the module for the individual connection of the wires of a cable.

According to a characteristic of the invention, the contacts of a group are successively alternated along two axes of parallel alignment which define two parallel or quasi-parallel V with the corresponding alignment axes of the other group. A contact and a contact immediately adjacent to the same group which are located on axes of different parallel alignment are positioned at a distance less than that separating two successive contacts located on the same alignment axis. The contact of each group which is furthest from the plane of symmetry of the module is the one closest to the end of this module where the cable arrives.

The invention also provides a terminal member for telecommunications cable having the characteristic of comprising a module as mentioned above.

The invention, its characteristics and its advantages are specified in the description which follows in conjunction with the figures mentioned below.

Figure 1 shows a perspective view of a terminal member for telecommunications cable comprising a connection module according to the invention.

Figure 2 shows a perspective view of the body of Figure 1 returned upside down and the connection module is partially dissociated.

Figure 3 shows a perspective view of the member of Figure 1 whose connection module is partially dissociated.

Figure 4 shows a bottom view of the insulating housing block for contacts of a connection module as shown in the figures mentioned above.

FIG. 5 presents a top view of the member presented in FIGS. 1 to 3.

FIG. 6 presents a left view of a member as presented on the Figures 1 to 3, whose housing block has been separated from the rest.

The connection module for telecommunications cable presented in Figure 1 is here assumed to be incorporated in a member 1 intended to allow the transmission of electrical signals from a cable telecommunications 2 to a communicating device, not shown. This communicating device includes for example one or more communication devices telecommunications and / or one or more computer devices capable of transmitting and / or receive signals via the telecommunications cable 2.

This cable is of the multi-wire type and it is assumed to consist of pairs or quarters planned to allow each the establishment of a circuit of different communication.

The member 1 is optionally incorporated into the device communicating to which it is associated, it can alternatively constitute an adapter or a socket for connecting the cable to the communicating device so removable.

In the example presented, the connection member 1 is assumed to include a standardized RJ 45 female socket whose external container is referenced 3 and a connection module according to the invention, shown here mounted on the same support plate 4. This support plate is for example a circuit board printed matter on which are provided conductive tracks, not illustrated, which allow interconnecting insulation displacement contacts 5, which can then be plugged in, carried by the connection module according to the invention and connection plugs 6 that the socket has. These contacts 5 and these plugs 6 are partially shown in Figure 2.

In an alternative embodiment not shown, it is not necessarily support plate provided and insulation displacement contacts are assumed to be made each at one end of a functionally individual busbar analogous to a conductive printed circuit track, each strip being immobilized in a determined position in the organ which comprises it. As it is known that these bars have the advantage of being able to be easily conformed and in particular folded as well as subject to need to allow the establishment of separate electrical connections from each other between the insulation displacement contacts that they are supposed to include in the case mentioned above and for example other contacts. These are for example those of an RJ45 socket, as in the example mentioned above. The shapes and securing of bars are not shown here and will not be further developed to the extent that they are well known techniques of the skilled person.

In one or other of the variants envisaged above and more particularly in the illustrated embodiment which is proposed by way of example, the module of connection essentially comprises self-stripping metal contacts 5 and a wire guide block 16 of insulating material. The latter is arranged to allow the individual positioning of the wires 7 of the cable 2 to be connected each in a slot insulation displacement 8 of one of the contacts 5.

The arrangement of these insulation displacement contacts 5 is here chosen in a way illustrated in Figures 2 and 3 and here detailed in conjunction with Figure 4. A example of contact is presented in figure 6, it includes a tail of insertion 5A, which is for example intended to be electrically connected by welding to a conventional conductive tracks and not shown of the support plate 4, then assumed to be of the printed circuit board type. Each contact 5, looking here supposed to be flat, comprises a slot 8 for holding the wire, here blind and opening to the opposite of the plug-in tail, the mouth of which is intended to cut so as to be able to at least partially eliminate part of the insulating sheath which is conventionally coated with a wire 7 of telecommunications cable 2.

The contacts 5, here provided identical and in even number, are divided into two groups of the same even number of contacts and according to a V-shaped arrangement, the position of the contacts of one group being symmetrical to those of the other group by with respect to a plane oriented perpendicular to the support plate and having the axis of symmetry XX 'of the V for trace at the level of this plate, like the at least partially shows Figures 1, 2, 3 and 5.

The contacts of a group are successively alternated along two axes of parallel alignment, or at least approximately parallel, referenced AA ', BB' for one of the groups and CC ', DD' for the other and which define two V with parallel or almost parallel branches in the plane of the support plate. A contact of a group and an immediately adjacent contact of this group are therefore each aligned on a different one of the two parallel axes of alignment of the group. This arrangement makes it possible to arrange the adjacent contacts of a group at a sufficient distance from each other by reducing the size of the module according to axis XX 'with respect to a solution where the adjacent contacts of a group would be aligned along the same axis.

In a preferred embodiment, the aligned contacts are distributed with identical spacings along their alignment axis regardless of which one alignment axes considered among those defined previously for the module.

Furthermore, as shown in FIG. 4 where the bottom of the wire guide block 16 is shown seen from below and where we see the openings 9, section complementary to that of the contacts 5, through which the latter enter said block, the pitch PI between the slots 8 of two adjacent contacts located at the end of a group is less than the pitch PE between the slot 8 of that of these two contacts located the least at the end and the slot of the adjacent contact which is still located less at the end than he in the group that includes them. To the extent that the slot 8 of a contact 5 is here assumed in the alignment of the tail 5A of this contact, it has been assimilated in FIG. 4 the position of the slot of a contact with the position of the tail 5A of this contact which is aligned with it.

A greater distance is therefore provided between contacts of the same group with a step of two, the distance separating two successive contacts of the same alignment in a group, such as that between the contacts referenced 5 ₁ and 5 ₃ , being greater to that separating one of these contacts from an adjacent contact located on the parallel alignment, such as that between the contacts referenced 5 ₁ and 5 ₂ or that between the contacts referenced 5 ₂ and 5 ₃ .

In practice, the contacts of a group are paired, each pair comprising two adjacent contacts, such as 5 ₁ and 5 ₂ , which are each located on one of the two alignment axes specific to the group. Two pairs of successive contacts of the same group, such as the pairs of contacts 5 ₁ and 5 ₂ or 5 ₃ and 5 ₄ , having a common adjacent contact, such as 5 ₂ , which is offset differently with respect to the two contacts, such 5 ₁ and 5 ₃ , arranged on the same other alignment axis with which it is adjacent. The part possibly facing this so-called common contact of one of these two adjacent contacts, ie here 5 ₃ , is then smaller than that possibly facing it of the other, ie here 5 ₁ , with which said common adjacent contact is paired.

This allows in particular, when the wires to be connected with a cable telecommunications are paired two by two to connect the two wires twisted from a pair to adjacent contacts respectively located on two parallel alignments of the same group and consequently to be able to obtain that the two successive contacts at the same alignment and which are provided connected to wires belonging to different pairs, either at a distance one of the other which is greater than that separating the contacts to which are planned to be connected two wires of a pair.

This is advantageous insofar as the capacitive influence of a pair on its neighbor at the insulation displacement contacts of the connection module where these pairs are connected is reduced the smaller the face-to-face portions of the contacts concerned, as symbolized by the overlap length of the face-to-face zones referenced PA for the contacts 5 ₂ and 5 ₃ in FIG. 4.

The arrangement in V of the two groups of contacts 5 makes it possible to penetrate the end of the telecommunications cable stripped of its sheath to free the wires to be connected at least up to the level of the V formed by the contacts 5, so as to introduce the wires into the slots of these contacts passing through the interior of the V, the point of development of the cable then being possibly and advantageously located inside the V. The positions of the insulation displacement contacts 5 and more precisely those of their slots 8 in the connection module allow wiring to be carried out in which the wire portions of a pair have practically the same length from the point of development of the cable of which they are a part, up to the contact in which slot each wires is individually inserted by force, the contacts for the two wires of a pair being for example the contacts 5 ₁ and 5 ₂ or the contacts 5 ₃ and 5 ₄ or one or the other symmetrical contact res of those mentioned above. Due to the V-shaped arrangement of the contact groups, the lengths of the wire portions of pairs connected to contacts arranged parallel to the same group are likely to be very close in length insofar as it is possible to place the contacts aligned on the axes AA 'and DD' furthest from the axis of symmetry XX 'of the V closest to the planned point of blooming of the cable 2 and consequently of the end of the connection module at the level of which reaches this cable than those aligned on the more adjacent axes BB 'and CC'.

As usual in the matter, the connection of the wires 7 of a cable 2 to the insulation displacement contacts 5 of a connection module is facilitated by the presence an auxiliary wire guide block, such as that referenced 16 in FIGS. 1 to 3 and 5, 6.

This block is here assumed to be made of a rigid, electrically insulating material, here supposedly based on an isosceles trapezoidal shape, in which are formed individual passage ducts 9 for the contacts 5 and guide grooves 10 for each of the wires 7 of the cable to be connected. The individual conduits of passage 9 which here has a cross section corresponding to that of a contact pass through the block in parallel and end up in the guide grooves 10, so that the contact is arranged transversely to the groove of guidance where it ends and for example perpendicular to the longitudinal axis of the groove if the latter is rectilinear as shown. It is of course possible to produce at least partially curved guide grooves.

The slot 8 of a contact opens in the groove 10 of a wire guide block 16 where this contact succeeds when the block is positioned against the support plate 4 where these contacts are positioned. The depth of the grooves 10 is here determined by so as to allow the insertion of a wire to the holding position and by example at the bottom of the slot 8 of the contact 5 opening in this slot, when the wire guide block is in position against the support plate 4.

The positioning of the individual passage conduits 9 relative to the grooves 9 is a function of that of the contacts with respect to each other, it leads to this as the contacts of the same group which are aligned along two parallel axes are located either at the ends of the innermost grooves of the V for the group which includes them, that is the outermost of this V, two neighboring contacts of a group being located one towards the inside of the V in the groove where it terminates and the other outward.

In the embodiment presented, there is also provided a thread holding slot by pinching of this wire covered with its individual insulating sheath in a slot of wedge 17 located in each groove 17 near the end of this groove which is opposite to that where the contact 5 terminates in said groove, as shown in figures 5 and 6.

As already indicated above, it is expected that the wires of a cable to be connected enter the grooves through the innermost end of these grooves of the V and the wire guide block has a hollow central zone ending in a opening 18 for passage of wire in the end wall of this block at the level of which the cable is likely to be introduced into the connection module. The hollow central zone and the grooves 10 open on the other side of the block by report to the bottom of this block. This allows the introduction from above of a cable 2 in block 16 and the insertion from above of the wires 7 of this cable into the grooves 10 and in the slots 8 of the contacts 5 of the connection module housed in this block. It is therefore possible to use a usual connection tool, manual or machine-driven, to ensure the insertion of the wires into the slots with the type of wire guide block envisaged here.

It is also possible to hold it in place, on a connection module according to the invention, a cable whose wires are inserted into the slots of the contacts of the module by means known to those skilled in the art and arranged for example at the level of a cover, not shown coming to cap the module or else of a housing in which is housed the member 1 equipped with the connection module here considered. Such a cover or such a housing can also be made so known to those skilled in the art for constituting electromagnetic shielding.

It should also be understood that the insulation displacement contacts here supposed to be plans for reasons for simplification of the presentation and insofar as such a form of realization is often advantageous, can also be realized in a form slightly different and only planar with a certain approximation, as known to those skilled in the art, such as for example the contacts known insulation displacement devices with Z cross section.

Claims (10)

1. A connection module for wires (7) of a telecommunication cable, said module incorporating insulation displacement contacts (5) with wire-retaining slot(s) (8) provided with wire-inserting mouths opening on the same side relative to the module for individually connecting the wires of the cable, said contacts being symmetrically divided into two groups, disposed in a V-shape, and each including an even number of contacts, characterised in that the contacts of a group alternate successively along two at least approximately parallel alignment axes (AA', BB' or CC', DD') that define two V-shapes parallel or virtually parallel to the corresponding alignment axes of the other group, one contact and an immediately adjacent contact of the same group, situated on different parallel alignment axes, being positioned at a distance less than that between two successive contacts situated on the same alignment axis, the contact of each group that is farthest from the plane of symmetry of the module being that which is closest the end of said module at which the cable enters.
2. A connection module according to claim 1, characterised in that its aligned contacts are identically spaced along their alignment axis regardless of which of the alignment axes of the contacts of the module is referred to.
3. A connection module according to either claim 1 or claim 2, characterised in that the contacts of a group are paired, each pair including two adjacent contacts (5₁, 5₂) each of which is situated on one of the two alignment axes specific to the group, two successive pairs of contacts (5₁, 5₂ and 5₃, 5₄) of the same group having a common adjacent contact (5₂) which is offset differently relative to the two contacts (5₁ and 5₃) disposed on the same other alignment axis and to which it is adjacent, so that the part possibly facing it of one of those two adjacent contacts is smaller than that possibly facing it of the other one with which said common adjacent contact is paired.
4. A connection module according to any of claims 1 to 3, characterised in that it includes a wire-guide block (16) in which passages (9) are formed for the contacts and on which guide grooves (10) are formed for the wires (7) to be connected of the cable, the passages passing through the block from its bottom and opening into the guide grooves so that a contact inserted into a passage of this kind is disposed transversely relative to the groove and the wire-retaining slot of that contact opens into that groove, said grooves being symmetrically arranged in a fan-shape on each side of a central part at one end of which the cable whose wires are to be connected is inserted.
5. A connection module according to claim 4, characterised in that it includes a wire-guide block (16) having grooves provided with slots (17) for wedging insulated wires by clamping the wire covered with its individual insulation.
6. A connection module according to claim 5 characterised in that it includes a wire-guide block (16) having a succession of grooves associated with each group of contacts, each groove accommodating a wire-retaining slot of one of the contacts at one end and an insulated wire wedging slot at the other end, the positions of the retaining slots (8) and the wedging slots (17) at opposite ends of the groove being reversed from one groove to the next in the succession concerned.
7. A connection module according to any of claims 4 to 6, characterised in that it includes a wire-guide block (16) including wire-guide grooves symmetrically disposed on either side of a hollow central area of the module enabling wires to be connected of a cable to be passed from an open end of the block for the cable to the interior of the grooves, said grooves and said central area opening onto the other side of the block relative to the bottom of the block.
8. A connection module according to any of claims 1 to 7, characterised in that its contacts are carried by a support board (4), in particular a printed circuit card.
9. A connection module according to any of claims 1 to 7, characterised in that its contacts are formed at the ends of individual conductive strips rendered immobile.
10. A terminal element for a telecommunication cable, in particular an adapter or a connector, characterised in that it includes at least one connection module according to any of claims 1 to 9.

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