FR2688354A3 - Connectors for screened cables - Google Patents

Abstract

The present invention relates to a connection panel (10) having a series of openings for housing electrical connectors (23) and provided with a means for terminating a series of electrical cables, which comprises a busbar (17) mounted on the body of the connection panel and electrically insulated from the latter, and a series of cable-retaining clamps (54) arranged on the busbar so that each accommodates a cable (26). The cable-retaining clamps are generally C-shaped and include a part which limits movement of a cable within the clamp, and the termination means includes, at least on one side of each clamp, a foot (tab) (56), the foot and the movement-limiting clamp part interacting in order to prevent movement of a cable within the clamp in the direction of insertion or removal of the cable.

Description

The present invention relates to connectors for shielded cables, in

especially for cables

  shielded for data communications.

  In the installation of equipment used in the wiring of data communications equipment, it is often necessary to connect large numbers of shielded cables to a common ground In addition, unwanted cable movements must be prevented In a typical application, it is necessary to connect 48 cable shields with 48 connectors of the connector or jack type to a common point. Such an operation not only can be time-consuming and labor-intensive, but it is often made more difficult by the sheer volume. of the connections involved and by the variety of types of cables and of the connection techniques which may be involved. shield easily crashes, which can be damaging to

its shielding properties.

  The inventors have identified a need for a connection arrangement which simplifies the connection process and which reduces the time involved in the

installation.

  The inventors have also identified the need for a connection or arrangement which reduces the

  risk of damaging the cable shields.

  To meet these needs, the invention provides a connection panel having a series of openings for receiving electrical connectors and provided with means for terminating a series of electrical cables to be connected to the electrical connectors, the termination means comprising a busbar, mounted on the body of the switchboard, and a series of cable retaining clips arranged on the busbar so as to each receive a cable, the busbar being electrically isolated from the body of the switchboard, characterized in that the cable retaining clamps are generally C-shaped and include a part limiting movement of a cable inside the clamp, and in that the termination means include a tab arranged at least on one side of each clamp, the tab and the clamp part which limits the movement cooperating to prevent movement of a cable inside the clamp in the direction of cable insertion in

  the clamp or removal of the cable out of it.

  The legs can, in particular, be curved. The legs may be integral with the busbar, or may alternatively be of a

in one piece with the pliers.

  A tab can be placed on each side of

each clamp.

  The cables can be shielded cables, the clamps and the legs then coming into abutment on the

cable shields.

  The bus bar means may include a first bus bar on which are arranged a series of pliers and associated legs, and a second bus bar separable from the first bus bar and on which are arranged another series of pliers and associated legs. These and other objects, advantages, and features of the present invention will be better

  understood using the following description of a mode

  of preferred embodiment with reference to the accompanying drawings in which: Figure 1 is a rear view of a connection panel suitable for the connection of shielded cables on socket outlets; Figure 2 is a plan of the connection table of Figure 1; Figure 3 is a plan of a busbar mounted on the connection panel of Figures 1 and 2; Figure 4 is a rear view of the bus bar of Figure 3; Figure 5 is a perspective view from behind, partly in broken lines, of the patch panel assembled for use; Figure 5a is an enlarged view of a cable clamp showing how a cable is engaged therein; Figure 5b is an enlarged view of a cable engaged in a cable clamp; Figure 6 is a partially exploded front perspective view of the connection panel; Figure 7 is a perspective view of a second embodiment of the bus bar showing how shielded cables are retained; Figure 8 is a perspective view of a clamp according to an embodiment of the present invention. The connection panel 10 of Figures 1, 2, 5 and 6 includes a front wall 12 and a bottom wall 14 In the bottom wall are provided a series of holes 16 for attaching one or more bus bars 17 (Figures 5 and 6) and a series of slots 18 for fixing the cables on the bottom wall in an orderly manner, by means of plastic ties 19,

for example (Figure 5).

  In the front wall are provided a series of holes 20 for attaching cable retaining devices 21, as shown in Figure 6, and a series of eight rectangular openings 22 The connection panel could be used to wire unshielded cables, but it is particularly suitable for

shielded cables.

  Typically, a cable coming from a data communications output comprises four pairs of wires (Figure 7) around which an aluminum foil or a braided shield 26 is wound. This shield provides protection against external interference. , for example a noise, which

  can corrupt data transmitted on wires.

  An outer sheath of plastic or rubber 28 extends over the length of the cable At the connection panel, a number, which can go up to 48 (see Figure 5), of cables 29 are terminated and connected to sockets output to be connected to communications devices, for example computer terminals or telephones The sockets 23 (Figures 5, 6) are housed in the openings 22 at the front of the connection panel and can typically be of the type sold by Mod-Tap Limited under the trademark EUROMOD and described in the patent application also under examination PCT / U 591/08100 of the present inventors The structure of these socket connectors is modular and three units can snap into each openings 22 as shown in Figure 1 Since each unit can carry two sockets, it is possible to mount a total of 48 sockets on the table Blind tables 70 (Figure 6) can nt be used to block any

unwanted opening.

  The socket units are connected to the wires of each cable by means of offset connectors (Figure 5, 6). An example of a suitable connector is that which is described in the patent application also under examination GB 9 112 604 of the applicants and sold by Mod-Tap Limited under the trademark KATT Other types of connectors are also suitable. The busbar performs two functions Firstly, it constitutes a connection point for the shielded cables on the connection panel and, secondly, it constitutes a common ground for all the cable shields In the embodiment of Figure 7, a mounting screw 30 fixes the busbar to the bottom wall of the connection panel via a mounting hole 16 provided at the end (Figure 2) Three other screws are arranged along the length of the bar manifold in correspondence with the remaining holes 16 on the bottom wall At each of the mounting points, a non-conductive bushing and washer, for example a nylon bushing 32 and a nylon washer 34, electrically separate the busbar from the wiring board. forming separate masses for the

shielding and for the board.

  The busbars of Figures 3 to 6 differ from that of Figure 7 However, they are in principle the same although the embodiment of Figures 3 to 6 constitutes the preferred structure Two separate busbars 40 and 41 are provided in this mode The first collector bar is mounted on the lower wall 14 and the wiring is attached thereto Then, the second collector bar is mounted above the first collector bar, spaced from the latter by a series of lugs 42 (Figures 4 à 6) The remaining cables can be attached to the second busbar when it is positioned In the arrangement of Figure 7, the busbar is a single C-shaped channel 60 which, although suitable, makes the 'cable attachment to the bottom wall 46 (Figure 7) more difficult than in the arrangement according to Figures

3 to 6.

  Since the configuration of the two layers or

  two busbars is similar, the description

  will be limited to the top layer.

  The busbar 40 of Figures 3 to 6 comprises a rectangular metal sheet provided with a side flange 44 to which are suspended a series of legs 42, an opening 46 and a U-shaped recess 48 being formed in each leg to fix this busbar to the lower busbar The end tabs include projecting connection points 50 which screw into the busbar and which allow cables to be attached to the busbar, for example to connect the busbar to the ground at a desired point, for example a mounting cabinet, for

  via a ground wire 51 (Figure 5).

  In the busbar 40 is formed a series of openings 52 spaced on two lines which

  extend over the length of the busbar 40.

  As can be seen in Figure 7, each of these openings receives a cable retaining clip 54 The openings are shown circular, although this shape is not mandatory Each of the clamps carries on its underside a retaining tab (not shown) which fits into the opening The advantage of a circular opening is that the orientation of the opening relative to the busbar is without

  importance, which facilitates manufacturing.

  A pair of positioning tabs 56 is disposed on each side of each opening. In the embodiment shown, these tabs are formed by stamping the tab on the bus bar and bending the tab upward. Alternatively, the legs could be separate elements attached to the busbar or could be formed on the clamps, as shown in Figure 8 While the legs are shown straight, they are in practice curved since the nature of the material is such that the metal bend will be rounded and not concentrated along a line The purpose of the legs can be understood from

Figures 5 to 7.

  As seen in Figures 5 a, 5 b and 7, the clamps include elastic C-shaped clamps in the upper end of which is formed a channel 58 extending inwardly When a cable is attached to the busbar, the outer sheath 28 is first removed by cutting to expose the shield 26 (Figure 5 a) and the cable is inserted into the clamp (Figure 5 b) Originally, the underside of the channel 58 abuts on the shield 26, which forces the elastic clamp to open in opposition to its natural elasticity When the cable has passed the channel 28, the clamp closes around the shield. The limit of movement of the cable in the clamp is defined by the lugs 56 Since these are curved as described, they adjust around part of the circumference of the cable and they prevent, if they are positioned correctly relative to the channel 58 of the clamp, any lateral movement of the cable in the clamp In addition, the tabs 56 prevent the cable from being forced into the clamp on the rear 62 of the clamp which is narrower than the cable, which could cause crushing of the shield and loss of shielding properties Furthermore, since the combination of channel 58 and legs 56 firmly holds the cable in position, there is no need for the operator to press on the clamps to fix the cable,

  an operation which would risk crushing the shielding.

  In the embodiment of Figure 8, the legs are formed as an extension of the side of

  the clamp which comes into abutment on the busbar.

  This arrangement eliminates the need to stamp the tabs 56 from the busbars which reduces the

assembly time and costs.

  Many modifications can be made to the embodiments described. For example, it is not necessary that there is a tab on each side of the clamp, although this is preferable. A single tab is sufficient for a

proper cable retention.

  The apparatus described can also be used to terminate unshielded cables. In such cases, the isolation of the busbar from the rest of the panel is unimportant, but the invention is advantageous since it allows cables to be appropriately arranged along the busbar and the arrangement of the legs 56 ensures

  that the cables are firmly retained.

Claims (7)

  1 connection panel (10) having a series of openings (22) for receiving electrical connectors (23) and provided with means for terminating a series of electrical cables to be connected to the electrical connectors, the termination means comprising a busbar (17), mounted on the body of the connection panel, and a series of cable retaining clips (54) arranged on the busbar so as to each receive a cable (26), the busbar being electrically insulated of the body of the connection panel, characterized in that the cable retaining clamps are generally C-shaped and include a part (58) limiting movement of a cable inside the clamp, and in that the termination means includes a tab (56) disposed at least on one side of each clamp, the tab and the clamp portion which limits the movement cooperating to prevent movement of a cable inside the clamp e in the direction of insertion of the cable into the clamp or removal of the cable from this one.   2 connection panel according to claim 1,   characterized in that the legs are curved.   3 patch panel according to claim 1 or 2, characterized in that the legs are of a single holding with the busbar.   4 connection panel according to claim 1 or 2, characterized in that the legs are of a single holding with pliers.   Connection panel according to any preceding claim, characterized in that a lug is arranged on each side of each clamp.   6 switchboard according to any preceding claim, characterized in that the cables are shielded cables and the clamps and the legs abut on cable shields.   7 connection panel according to any preceding claim, characterized in that the busbar means comprises a first busbar (40) on which are arranged a series of clamps (54) and associated tabs (56), and a second bar collector (41) separable from the first collector bar and on which are arranged another series of clamps (54) and lugs associated (56).   to terminate unshielded cables In such cases, the isolation of the busbar from the rest of the switchboard is unimportant but the invention is interesting since it allows cables to be appropriately arranged along the busbar and that the arrangement of the legs   56 ensures that the cables are firmly retained.