NZ626667B2 - Telecommunications cabling system, and electrical connection module and shielding interface therefor - Google Patents

Abstract

telecommunications cabling system, including: an earthed support (12) and at least one connection module (100) mounted to the earthed support (12). The or each said connection module (100) includes: a housing for a plurality of electrical contact members, the housing having a plurality of recesses to receive wires of at least one shielded cable (50a); and at least one opening to receive an end of an electrical connector (400) to place electrical contacts at the end of the electrical connector (400) in direct or indirect electrical communication with at least some of the wires. The system also includes a shielding interface for the connection module (100). The shielding interface is simultaneously contactable with shielding (52a) of the shielded cable (50a), a corresponding shielding interface of the electrical connector (400), and the earthed support (12). The housing also includes at least one groove for receiving a conductive finger of the shielding interface of the connection module (100). The finger is contactable with the shielding interface of the electrical connector. to receive wires of at least one shielded cable (50a); and at least one opening to receive an end of an electrical connector (400) to place electrical contacts at the end of the electrical connector (400) in direct or indirect electrical communication with at least some of the wires. The system also includes a shielding interface for the connection module (100). The shielding interface is simultaneously contactable with shielding (52a) of the shielded cable (50a), a corresponding shielding interface of the electrical connector (400), and the earthed support (12). The housing also includes at least one groove for receiving a conductive finger of the shielding interface of the connection module (100). The finger is contactable with the shielding interface of the electrical connector.

Description

TELECOMMUNICATIONS CABLING SYSTEM, AND ELECTRICAL CONNECTION MODULE AND SHIELDING INTERFACE THEREFOR CROSS-REFERENCE TO RELATED APPLICATIONS The contents of Australian Patent Application No. 2011265514, entitled "Telecommunications cabling system", Australian Patent Application No. 2011265515, entitled "Shielding interface for an electrical connection module", and Australian Patent Application No. 2011265516, entitled "Electrical connection module", are hereby incorporated by reference in their entireties.

TECHNICAL FIELD The described embodiments relate to a telecommunications cabling system, to an electrical connection module, and to a shielding interface for an electrical connection module, for use in a telecommunications network.

BACKGROUND In the field of telecommunications, wires used to carry the telecommunications signals are susceptible to noise from a variety of sources, including neighbouring wires in the same cable which may introduce near-end crosstalk (NEXT) or far-end crosstalk (FEXT), and nearby cables which may introduce alien crosstalk (AXT). As data transmission rates increase, the effect of this noise on error rates also increases.

Various attempts have been made in the past to minimise noise in telecommunications signals. For example, in twisted-pair cabling used in telecommunications networks, adjacent pairs in the cable generally have different twist rates, and the pairs may be individually shielded from electromagnetic interference using foil. The collection of pairs in the cable may be further shielded using a foil screen. This type of cable generally includes a grounding wire, also called a drain wire, to provide a grounding for the cable.

Typically, cables of the type described above are used to cross-connect telecommunications equipment at a premises. This may take place via patch panels which may include front and rear connection locations.

Another type of cabling system, known in the art as a "patch-by-exception" system, has hardwired cross-connections between connection modules to electrically connect ports of a data or voice switch/router with end user equipment. The connection modules generally include insulation displacement contacts (IDCs) onto which wires of respective twisted- pair cables are terminated to form the cross-connections, and the IDCs may include a spring contact which can be separated to break the connection. This type of connection module is sometimes known as a disconnect module. For example, the spring contacts may receive electrical contact-bearing fingers of a printed-circuit board (PCB) of a patch cord, such as those of the type shown in PCT application (), the contents of which are hereby incorporated by reference in their entirety. The ends of such a patch cord may be plugged into the disconnect modules at any desired pair of locations in order to divert the data or voice signal from its original hardwired path to a new path between the desired pair of locations, thus creating a patched configuration which is an exception to the original (default) hardwired configuration.

It would be desirable to provide a system with decreased susceptibility to electromagnetic interference, or at least to provide a useful alternative.

SUMMARY OF THE INVENTION According to one aspect of the invention there is provided a telecommunications cabling system, including: (a) an earthed support; (b) at least one connection module mounted to the earthed support, including: (i) a housing for a plurality of electrical contact members, the housing having a plurality of recesses to receive wires of at least one shielded cable and having at least one groove; (ii) at least one opening to receive an end of an electrical connector to place electrical contacts at the end of the electrical connector in direct or indirect electrical communication with at least some of the wires; and (iii) a shielding interface for the connection module that is simultaneously contactable with shielding of the shielded cable, a corresponding shielding interface of the electrical connector, and the earthed support, the shielding interface for the connection module including at least one electrically conductive finger to seat within the at least one groove, the at least one electrically conductive finger contactable with the shielding interface of the electrical connector.

The term "comprising" as used in this specification and claims means "consisting at least in part of". When interpreting statements in this specification and claims which include the term "comprising", other features besides the features prefaced by this term in each statement can also be present. Related terms such as "comprise" and "comprised" are to be interpreted in similar manner.

The shielding interface may be contactable with the earthed support by opposed ends of an electrically conductive connector bar.

The at least one connection module may be mounted to the earthed support by a cable management member. The cable management member may include a bracket for the electrically conductive connector bar.

In certain embodiments, the electrically conductive connector bar is contactable with the shielding interface by an interference fit.

The shielding interface may include at least one conductive bracket to receive the shielding of the at least one shielded cable, and to fasten the shielding to the shielding interface. The conductive bracket may be a conductive clasp. The clasp may have a substantially C- shaped cross section. The conductive clasp may have a recess to receive a cable tie to fasten the conductive clasp to the shielded cable. The or each said conductive bracket may extend from an elongate conductive strip or bar.

In certain embodiments, the shielding interface includes retaining means for retaining the shielding interface on the housing of the connection module. The retaining means may include one or more fingers configured to bear against the housing. The fingers may be received in grooves of the housing. The retaining means may include one or more apertures shaped to fit corresponding protrusions on the housing. Alternatively, or in addition, the retaining means may include one or more protrusions shaped to fit corresponding apertures in the housing. The one or more apertures and/or the one or more protrusions may be disposed oppositely to the one or more fingers on the shielding interface.

In certain embodiments, the housing includes an outer shell to which the shielding interface is attached. At least part of the outer shell may be conductive. In certain embodiments, the outer shell includes a conductive polymer. The conductive polymer may be a metallised polymer.

In embodiments with a conductive outer shell, the electrical contact members may be received in an insulating means of the housing to prevent electrical communication between the outer shell and the electrical contact members. The insulating means may include a plurality of insulating members. Each insulating member may include an upper pair of cavities and a lower pair of cavities to receive respective pairs of electrical contact members. The insulating members may have a central axis which is parallel to a long axis of the connection module, the cavities being angled at 45 degrees to the central axis.

In certain embodiments, the connection module includes two rows of pairs of insulation displacement contact slots. The electrical contact members may include bifurcated contact arms extending into respective insulation displacement contact slots for electrical connection to the wires of the shielded cable when seated in the insulation displacement contact slots. The or each opening of the housing may be arranged between opposed pairs of slots in said rows of slots, each being shaped to receive the end of an electrical connector. A resilient end of each electrical contact member of an upper row (of the two rows of pairs of insulation displacement contact slots) may be in contact with a resilient end of a corresponding electrical contact member of a lower row.

In certain embodiments, wire-receiving recesses of the insulating means are accessible via the recesses of the connection module housing.

Other embodiments provide an electrical connection module, including: a plurality of electrical contact members seated in a housing, the housing having a plurality of recesses to receive wires for termination onto the electrical contact members, wherein the housing includes an outer shell at least part of which is electrically conductive.

Advantageously, the electrical conductivity of the outer shell provides a means of reducing alien crosstalk which may otherwise affect the signal propagating through wires terminated onto the electrical contact members.

Further embodiments provide a housing for an electrical connection module, including: an outer shell having a cavity to receive insulating means for seating wire termination ends of a plurality of electrical contact members, and a plurality of recesses to receive wires for termination onto the electrical contact members; and an inner shell having contact-receiving recesses for receiving resilient ends of the electrical contact members, the resilient ends being disposed opposite the wire termination ends; the inner shell being couplable to the outer shell; wherein at least part of the outer shell is electrically conductive.

Yet further embodiments provide a shielding interface for an electrical connection module, the electrical connection module being configured to receive wires of a shielded cable, the shielding interface including at least one engagement member for establishing an electrical connection with shielding of the shielded cable.

BRIEF DESCRIPTION OF THE DRAWINGS Presently preferred embodiments of the invention will now be described, by way of non- limiting example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of an example of a telecommunications cabling system including connection modules mounted to a back-mount frame; Figure 2 is a partial exploded view of the system of Figure 1; Figure 3 is a detail of part of the system of Figure 1; Figure 4 is a top plan view of a connection module having a plurality of shielded cables terminated thereon; Figure 5 is a perspective view of the module of Figure 4; Figure 6 is a perspective view of the module of Figures 4 and 5, prior to termination of the cables; Figure 7A is an exploded view of the module of Figure 6; Figure 7B is a detail of part of Figure 7A; Figure 8A is a bottom plan view of the module of Figure 6; Figure 8B is a rear plan view of the module of Figure 6; Figure 9A is a rear plan view of an example of a contact carrier for use with the module of Figure 6; Figure 9B is a front plan view of the contact carrier of Figure 9A; Figure 9C is a top plan view of the contact carrier; Figures 9D and 9E are front and rear perspective views, respectively, of the contact carrier; Figure 10A is a top perspective view of an example of a shielding bar for use with the connection module of Figure 6; Figure 10B is a top plan view of the shielding bar of Figure 10A; Figure 10C is a front plan view of the shielding bar; Figure 10D is a right-side view of the shielding bar; Figure 11A is a top perspective view of an example rear-facing patch plug; Figure 11B is an exploded view of the patch plug of Figure 11A; Figure 11C is a cross-section through the line A-A of Figure 11A; and Figure 12 shows a side view of Figures 4 and 5.

DETAILED DESCRIPTION Where the terms "front", "rear", "top", "bottom", "upper", "lower" and the like are used below, it will be understood that these are used simply to describe the orientations of various components relative to each other, and are not intended to be construed in an absolute sense. Accordingly, the skilled person will understand that these terms should be interchanged appropriately when the orientation of the system (relative to a user, for example) is changed.

Referring to Figures 1 to 3, there is shown a patch-by-exception telecommunications cabling system 10 including an earthed (grounded) support (backmount frame) 12 to which connection modules 100 are mounted, via respective cable managers 150. In use, telecommunications cables 50a housed in backmount frame 12 can be fed through cable retention members 156 on respective top surfaces of the cable managers 150, and wires of the cables 50a terminated on the connection modules 100 (Figure 4).

Backmount frame 12 can be earthed by any suitable means known in the art, for example by connection to a telecommunications grounding busbar (TGB) and/or the Telecommunications Main Grounding Busbar (TMGB) of an electrical/telecommunications installation.

With reference to Figure 7A, each connection module 100 includes a housing for a plurality of electrical contact members 212. Each electrical contact member includes an insulation displacement contact (IDC) which is seated inside the housing in a manner which will later be described. The housing includes an outer shell 200 and an inner shell 220 between which electrical contact members 212 are retained.

The housing 200, 220 has a plurality of recesses 202 (Figure 8) to receive wires of at least one shielded cable 50a for termination of the wires onto the electrical contact members 212. The housing also includes an opening to receive an end of an electrical connector, for example a front-facing patch plug 300 or a rear-facing patch plug 400, to place electrical contacts at the end of the patch plug 300 or 400 in electrical communication with at least some of the wires.

Returning to Figures 2 and 3, the system 10 includes a shielding interface 110a for each disconnect module 100. The shielding interface 110a is simultaneously contactable with shielding 52a of the shielded cable 50a (Figures 1, 4 and 5), a corresponding shielding interface 500 of the patch plug 400 (Figures 11B, 11C, 12), and the earthed support 12. A second shielding interface (not shown) is provided on the underside of disconnect module 100.

Advantageously, simultaneous contact between the shielding interface 110a, shielding of the cable 50a, the corresponding shielding interface 500 of patch cord 400 and earthed support (backmount frame) 12 provides a common earth throughout the electrical connections of the system 10, thereby improving the signal-to-noise ratio of the system 10.

With continued reference to Figures 1 to 3, each cable manager 150 includes a pair of projections 152 (only one of which is shown in the Figures), one at the rear of each of its end panels 151, which are shaped to sit within apertures 14 in the frame 12. End panels 151 of the cable manager 150 are preferably resilient panels which can flex to allow the projections 152 to locate within the apertures 14 and hold the cable manager 150 in place on the backmount frame 12.

At the front of each end panel 151, a hook 154 of a snap-fit mechanism projects forwardly of cable manager 150. The hooks 154 fit within corresponding recesses 104 (Figure 8B) of the disconnect module 100 to retain the module 100 on the cable manager 150.

The disconnect module 100 can accommodate up to 24 pairs of wires in each row, although it will of course be appreciated that any desired number of pairs can be accommodated in a single module. Thus, for example, the wires of six twisted-pair cables, each including four pairs 50a.1 to 50a.4 as shown in Figures 4 and 5, can be terminated on the top row of a module 100. Accordingly, the cable manager 150 includes, on its upper surface, six cable retention members 156, one for each cable. Each cable retention member 156 has a resilient downwardly-arched arm 156a located opposite a pair of protrusions 156b on the upper surface of the cable manager 150 (Figure 2). The gap between the arm 156a and the protrusions 156b is less than the thickness of a cable 50a, such that the cable 50a can be pushed into the gap, thereby deflecting the arm 156a upwards and allowing the cable to pass over the protrusions 156b such that the cable is retained between arm 156a and protrusions 156b. Similarly, wires of six twisted-pair cables can be terminated on the lower row of module 100 (for forming cross-connects between modules 100), and the cable manager 150 can include six further cable retention members on its lower surface.

The cables and cable retention members of the lower row/lower surface are omitted from the drawings for clarity.

In the system 10, a first set of cables 50a, which may each for example have one end connected to a port of a switch or router, may be passed through an aperture 16 in backmount frame 12. The wire pairs 50a.1 to 50a.4 of the first set of cables 50a are terminated onto the IDCs of upper rows 107 of a first set of disconnect modules 100. A second set of cables 50a, which may have their respective ends connected to end user equipment such as computer systems (provided with network interfaces), telephony equipment and the like, may also be passed through the aperture 16, and the wires of the second set of cables terminated onto the IDCs of upper rows 107 of a second set of disconnect modules 100. Hardwired (jumpered) cross-connects may then be formed by terminating a series of cables 50b (Figure 12) between respective lower rows 108 of the first and second sets of disconnect modules 100.

Cable manager 150 may include a plurality of forwardly projecting arms 158. The arms 158 provide mechanical support for disconnect module 100 along its length, particularly during termination of wires into IDC slots of the disconnect module 100 as will later be described.

Cable manager 150 includes a bracket to receive an electrically conductive connector bar 160. The electrically conductive connector bar 160 has at one end a finger 164 and at its opposite end two pairs of tines 162. As best seen in Figure 3, when the cable manager 150 is mounted to the backmount frame 12 and the disconnect module 100, the finger 164 of shielding connector bar 160 contacts with the backmount frame 12, and the top pair of tines 162 engages with a shielding bar 110 of the disconnect module 100 to form an interference fit. This ensures, when the backmount frame 12 is connected to a protective earth, that the shielding bar 110 is also earthed. The lower pair of tines 162 engages with the second shielding bar on the underside of module 100.

Referring now to Figures 6, 7A, 7B, 8A and 8B, there is shown a connection module 100 including an outer shell 200 and an inner shell 220. Housed between the outer shell 200 and the inner shell 220 are a plurality of electrical contact members 212 which are arranged as an upper row 212a and a lower row 212b. Blades 257a of the electrical contact members 212a of the upper row are at least partially exposed via recesses 202 (Figure 8A) between adjacent islands 107a of an upper row 107 of the module 100. Similarly, blades 257b of the electrical contact members 212b of the lower row are at least partially exposed via recesses 202 between adjacent islands 108a of a lower row 108 of the module 100.

The outer shell 200 preferably includes or consists of an electrically conductive material.

For example, the outer shell may be formed of a metal or a metallised polymer, and/or may include a conductive surface coating, for example a metallic coating. The entire outer shell may be electrically conductive, or may be formed of individual electrically conductive portions, which may or may not be separated by non-conductive portions. The electrical conductivity of the outer shell 200 provides shielding against alien crosstalk.

Each electrical contact member 212a, 212b may be received in an insulating means 214 comprising a plurality of insulating members (contact carriers) 900 (only three of which are labelled in Figure 7A). As shown in Figures 9A to 9E, each contact carrier 900 includes an upper pair 910 and a lower pair 912 of cavities. Accordingly, the blades 257a of upper contact members 212a are received in upper cavities 910, and the blades 257b of lower contact members 212b are received in lower cavities 912.

The insulating means 214 depicted in the drawings comprises a plurality of individual contact carriers 900. However, it will also be appreciated that the insulating means can be formed as a unitary component, for example by an injection moulding process.

To assemble the module 100, front ends (blades) 257a, 258b of electrical contact members 212a, 212b are inserted into contact carriers 900. Resilient rear ends 258a, 258b of the upper 212a and lower 212b contact members are inserted into recesses 224 of the inner shell 220 such that the rear ends 258a, 258b are in electrical contact, and outer shell 200 is then placed over the inner shell 220 and contact carriers 900 such that the contact carriers 900 are seated in cavities (not shown) in the outer shell 200, with a central rib 902 of each contact carrier 900 (Figure 9C) protruding into recesses 202 in the outer shell 200 (Figure 8A). When the module 100 is assembled, wire-receiving recesses 904 of the contact carriers 900 are accessible via the recesses 202 of the outer shell 200.

To assist in retaining the inner shell 220 on the outer shell 200, resilient tongues 222 are provided on the inner shell 220. These may engage directly with outer surfaces of the outer shell 200, or may be disposed so as to engage with protrusions 206 on the outer shell surface. The outer shell 200 may include protrusions 206 on both its upper and lower surfaces (only those protrusions on the upper surface being shown in Figure 7A).

The outer shell 200 of module 100 has a plurality of grooves 204 formed on its lower surface to receive fingers of a shielding bar as will later be described. The grooves 204 extend from the rear of outer shell 200, across the width of the lower surface to the front of the outer shell, and around the front, ending in a flattened portion 205 (Figure 6) in the lower row 108 of the module 100.

In like fashion, a further plurality of grooves may also be formed on the upper surface of outer shell 200, in opposed relationship to the grooves 204, if desired. If so, said grooves may end in flattened portions in the upper row 107 of the module 100.

Turning now to Figures 10A to 10D, there is shown a shielding bar 110a for use with the module 100 and system 10. The shielding bar includes an elongate body in the form of a bar or strip 111 of an electrically conductive material. The elongate strip 111 has projecting from one of its long edges a series of brackets or clasps 120a, each of which is associated with a finger 114 having a hooked end 115. Fingers 114 are rigid, but may also be made resilient if desired. The elongate strip 111 also has formed therein a series of holes 112 which are shaped and located to fit the protrusions 206 on the surface of the outer shell 200 of the connection module 100.

Each of the clasps 120a is substantially C-shaped in cross section and has a conduit 126 which is sized and shaped so as to accommodate a shielded cable 50a as shown in Figures 4 and 5. Each clasp 120a includes a pair of ears 122 defining a recess 124 therebetween.

The recess 124 is sized to fit a cable tie which is wrapped around the clasp 120a in order to secure the clasp 120a to the shielding foil 52a of the shielded cable 50a (Figures 4 and 5, cable tie not shown) in order to maintain electrical connection between the shielding bar 110a and the foil 52a.

To fit the shielding bar 110a to the module 100 shown in Figures 7A, 7B and 8A, inner shell 220 is removed (if it has previously been attached to outer shell 200). The fingers 114 are seated within grooves 204 on the lower surface of the outer shell 200, such that hooked ends 115 pass into the space defined between upper row 107 and lower row 108 of the module 100, and are received in seating regions 205 (Figure 6). Apertures 112 of the shielding bar are fitted over protrusions 206 on the lower surface of outer shell 200 to further assist in retaining the shielding bar 110a on the outer shell 200.

The shielding bar 110a shown in Figures 10A to 10D includes fingers 114 and hooked ends 115 for the purpose of establishing electrical contact with a corresponding shielding member of a patch plug, as will later be described. However, it will be understood that, if the shielding bar is to be used primarily to contact the foil (via clasps 120) of a shielded cable 50a, the fingers 114 may be omitted. A fingerless shielding bar of this type may be affixed to the outer shell 200 of a module 100 by fitting apertures 112 over protrusions 206 on the outer shell surface as previously described.

So, for example, if a first shielding bar has been attached by fitting its fingers 114 to grooves 204 in the lower surface of the outer shell 200, a second, fingerless shielding bar may then be attached to the upper surface of the outer shell 200. If both the upper and lower surfaces of the outer shell 200 include grooves 204, then it will be appreciated that a second, fingered, shielding bar 110b (Figure 12) may be attached in similar fashion to the first shielding bar 110a as described above.

Once the shielding bar or bars 110a, 110b have been attached to outer shell 200, inner shell 220 is then re-attached (or attached), the tongues 222 being pushed over the shielding bar (or bars) 110a, 110b so as to secure the inner shell 220 to both the shielding bar (or bars) 110a, 110b and the outer shell 200.

With reference now to Figures 11A to 11C, there is shown an electrical connector, in the form of a rear-facing patch plug 400, for use with the system 10.

The electrical connector 400 includes a connector body having a first member 402 and a second member which is made up of an upper shell 406 and a lower shell 404. Connector 400 further includes an electrical connector element 408, an insulation shield 410 and a biasing means 412, such as a spring. The first member 402 has an opening 414 formed through the member 402 for receiving one or more wires 417a from an electric cable 416 (only the very end of which is shown). The connector 400 can be used with any type of electric cable 416, but in the present example, the cable 416 is a shielded multi-cored cable with wires 417a corresponding to one or more twisted pairs 417. Each twisted pair 417 is surrounded by a metallic foil, and the collection of pairs is surrounded by a shielding foil (in similar fashion to shielding foil 52a of cable 50a, as shown in Figures 1, 4 and 5).

The first member 402 has latching means formed on an inner surface of the member 402.

The latching means includes one or more resilient latching posts 418a and 418b, each having an enlarged head portion which includes a shoulder that gradually increases the cross-sectional thickness of the head portion in a direction away from the exposed end of the latching post 418a and 418b. The head portion includes a flanged portion formed substantially normal to the length of the latching post 418a and 418b, which defines the transition from the larger cross-sectional thickness of the head portion to a smaller cross- sectional thickness of the latching post 418a and 418b. The latching posts 418a and 418b on the first member 402 are aligned with a corresponding recess 420 formed in the upper shell 406 of the second member. When the first member 402 and second member 404, 406 are coupled together, the head portion of a latching post 418a and 418b engages within a respective recess 420 in the upper shell 406 so that the resilience of the latching posts 418a and 418b securely holds the first member 402 and upper shell 406 together.

The first member 402 and the upper shell 406 of the second member, when coupled together, define a cavity between the parts 402 and 406. The upper shell 406 of the second member includes one or more wiring slots 422, each for receiving the end of a respective wire 417a from the cable 416. The wiring slots 422 are preferably IDC slots with contacts 424 which displace the insulation at the end of a wire within the cavity to establish electrical contact. For example, each contact slot 424 includes a surface made of a conducting material (e.g. copper) for directly contacting and making an electrical connection with the end of a wire (not shown) held in place by a wiring slot 422 of upper shell 406. The size of each contact slot 424 is sufficiently small to securely grip the end of a wire.

The connector element 408 includes one or more fingers 426, each finger 426 having a contact portion 428 for making electrical contact. The connector element 408 is substantially flat and has conducting paths (not shown) formed on the upper surface 430 and/or the lower surface 432 to provide an electrical connection between each contact slot 424 with a respective contact portion 428 of a finger 426. The connector element 408 may be a printed circuit board with etched conducting paths on one or both sides 430, 432. In the arrangement shown in Figure 11B, the contact slots 424 for receiving wires of a twisted pair are connected by conducting paths to respective contact portions 428 on adjacent fingers 426.

The connector element 408 is made for mating assembly with the upper shell 406. The connector element 408 includes one or more retaining notches 434a and 434b that engages with a corresponding retaining recess 436 formed in the upper shell 406 to securely couple the parts 406 and 408 together.

The adjustable insulation shield 410 is made of a non-conductive material (e.g. polycarbonate or polyvinylchloride), and has one or more guiding slots 446a and 446b formed in the shield 410. In some embodiments, as shown in Figure 11B, the guiding slots 446a and 446b are formed through sidewalls of the shield 410. In other embodiments, the guiding slots 446a and 446b may comprise recesses formed on the inner surface of the shield 410 but not formed through the sidewalls of the shield 410.

The guiding slots 446a and 446b engage with a corresponding guiding protrusion 448a and 448b formed on the outer surface of the lower shell 404, so that the shield 410 is able to move by sliding relative to the second member 404, 406, and wherein the movement of the shield 410 is guided by the guiding protrusions 448a and 448b. The guiding protrusions 448a and 448b are sufficiently long and snugly received in slots 446a and 446b so as to maintain stability of the shield 410 during movement.

The shield 410 is moveable along the length of the second member 404, 406 between an extended second position and a retracted first position, such that when the shield 410 returns to the first position, the contact portions 428 of the fingers 426 are exposed for direct contact. When the shield 410 is moved to the second position, the shield covers the contact portions 428 of the fingers 426 to minimise direct contact with the contact portions 428.

The electrical connector 400 includes biasing means 412 that tends to move the shield 410 towards the second position. The biasing means 412 may include a suitable form of compression spring, and may specifically comprise an S-shaped spring as shown in Figure 11B. The biasing means 412 is positioned between the shield 410 and the lower shell 404 of the second member, and the biasing means 412, when compressed, pushes against a boss portion 445 of the lower shell 404 and an inner wall of the shield 410 to bias the shield 410 towards the second position. The S-shaped spring shown in Figure 11B has one end registered with boss portion 445 and has its other end registered with another boss portion (not shown) on shield 410 so that the spring is retained in position during compression and expansion.

A u-shaped supporting portion 444 on lower shell 404 is positioned to mate with a complimentary u-shaped slot extending centrally in the direction of contact portions 428 on connector element 408. When connector 400 is assembled, supporting portion 444 assists in holding connector element 408 in place within the connector body. A keying finger 442 extends from lower shell 404 and aids in ensuring electrical connector 400 is correctly terminated when connecting to a patch panel, for example at connection module 100.

The electrical connector 400 includes, in the first member 402, a substantially T-shaped slot 460 to receive an upright portion 502 of contact shielding member 500. The shielding member 500 includes a recessed portion 510, disposed substantially perpendicular to the upright portion 502, around which the drain wire and shielding foil of cable 416 are wrapped.

As shown in Figure 11C, contact shielding member 500 includes an exposed portion 504 which protrudes through an opening in lower shell 404 so as to lie outside the body of the connector 400. Exposed portion 504 underlies the u-shaped supporting portion 444 of the lower shell 404.

Forward-facing patch plug 300 is configured substantially identically to rear-facing patch plug 400, except that a cable-receiving aperture of forward-facing plug 300 is located at an end of a first member of the plug 300 which is disposed opposite the contacts of the plug 300, in contrast to rear-facing plug 400 in which the cable-receiving aperture 414 is disposed adjacent the contacts 428 of the plug 400.

Turning now to Figure 12, the connector 400 is shown terminated at a connection module 100 to which are attached two shielding bars 110a, 110b. Upper shielding bar 110a is in electrical contact, via clasp 120a, with a shielding foil 52a of a first shielded cable 50a which includes four shielded pairs of wires (only three pairs 50.1a, 50.2a, 50.3a of which are shown) which are terminated onto IDCs of the upper row 107 of the module 100 as described above. Similarly, lower shielding bar 110b is in electrical contact via its clasp 120b with a shielding foil 52b of a second shielded cable 50b, which includes four shielded pairs of wires (only three pairs 50.1b, 50.2b, 50.3b of which are shown) which are terminated onto IDCs of the lower row 108 of the module 100.

Finger 114b of shielding bar 110b extends around the lower part 108 of module 100 and terminates in hooked portion 115b which is seated in a seat 205 of groove 204 (Figure 6).

With the connector 400 inserted, exposed portion 504 aligns and comes into contact with hooked portion 115b, such that the shielding bar 110b is in electrical contact with the contact shielding member 500, and in turn with the drain wire and shielding foil of the cable 416 of connector 400.

As can be seen from the foregoing discussion, each element of the system 10 includes means for electrically contacting (directly or indirectly) the grounded support means 12 such that a common earth is established throughout the system 10. In the absence of patch plugs 300, 400, the shielding foils of cables 50a (with wires terminated on upper row 107 of module 100) and 50b (with wires terminated on lower row 108) are in contact with respective shielding bars 110a, 110b, which in turn are in contact with the electrically conductive connector bar 160, which is in turn in contact with the backmount frame 12.

When a patch plug 400 is inserted, contact shielding member 500 (which is in contact with the drain wire and shielding foil of cable 416) comes into contact with shielding bar 110b (via hooked portion 115b as shown in Figure 12) so that the common earth is maintained.

The connection modules 100 depicted in the Figures and described above are disconnect modules for use in a patch-by-exception system. However, it will be appreciated that the connection module 100 may easily be modified in order to adapt it to different applications. For example, disconnect module 100 can be reconfigured to have a connection module function, a switching module function or an earth module function by replacing the pairs of electrical contact members 212a, 212b with suitable alternative contacts, as known in the art.

Throughout this specification, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims (25)

1. A telecommunications cabling system, including: (a) an earthed support; 5 (b) at least one connection module mounted to the earthed support, including: (i) a housing for a plurality of electrical contact members, the housing having a plurality of recesses to receive wires of at least one shielded cable and having at least one groove; (ii) at least one opening to receive an end of an electrical connector to place 10 electrical contacts at the end of the electrical connector in direct or indirect electrical communication with at least some of the wires; and (iii) a shielding interface for the connection module that is simultaneously contactable with shielding of the shielded cable, a corresponding shielding interface of the electrical connector, and the earthed support, the shielding interface for the 15 connection module including at least one electrically conductive finger to seat within the at least one groove, the at least one electrically conductive finger contactable with the shielding interface of the electrical connector.

2. A telecommunications cabling system according to claim 1, wherein the shielding 20 interface is contactable with the earthed support by an electrically conductive connector bar.

3. A telecommunications cabling system according to claim 1, wherein the at least one connection module is mounted to the earthed support by a cable management member.

4. A telecommunications cabling system according to claim 3, wherein the cable management member includes a bracket for the electrically conductive member.

5. A telecommunications cabling system according to claim 2, wherein the electrically 30 conductive member is contactable with the shielding interface by an interference fit.

6. A telecommunications cabling system according to claim 1, wherein the shielding interface includes at least one conductive clasp to receive the shielding of the at least one shielded cable.

7. A telecommunications cabling system according to claim 6, wherein the conductive clasp has a substantially C-shaped cross section.

8. A telecommunications cabling system according to claim 6, wherein the conductive clasp has a recess to receive a cable tie to fasten the conductive clasp to the shielded cable. 10

9. A telecommunications cabling system according to claim 6, wherein the or each said conductive clasp extends from an elongate conductive strip or bar.

10. A telecommunications cabling system according to claim 1, wherein the shielding interface includes retaining means for retaining the shielding interface on the housing 15 of the connection module.

11. A telecommunications cabling system according to claim 10, wherein the retaining means includes one or more fingers configured to bear against the housing. 20

12. A telecommunications cabling system according to claim 11, wherein the fingers are received in grooves of the housing.

13. A telecommunications cabling system according to claim 10, wherein the retaining means includes one or more apertures shaped to fit corresponding protrusions on the 25 housing.

14. A telecommunications cabling system according to claim 10, wherein the retaining means includes one or more protrusions shaped to fit corresponding apertures in the housing.

15. A telecommunications cabling system according to claim 13, wherein the one or more apertures and/or the one or more protrusions are disposed oppositely to the one or more fingers on the shielding interface. 35

16. A telecommunications cabling system according to claim 1, wherein the housing includes an outer shell to which the shielding interface is attached.

17. A telecommunications cabling system according to claim 16, wherein at least part of the outer shell is conductive.

18. A telecommunications cabling system according to claim 17, wherein the outer shell includes a conductive polymer.

19. A telecommunications cabling system according to claim 18, wherein the conductive 10 polymer is a metallised polymer.

20. A telecommunications cabling system according to claim 17, wherein the electrical contact members are received in an insulating means of the housing to prevent electrical communication between the outer shell and the electrical contact members.

21. A telecommunications cabling system according to claim 20, wherein the insulating means includes a plurality of insulating members.

22. A telecommunications cabling system according to claim 21, wherein each insulating 20 member includes an upper pair of cavities and a lower pair of cavities to receive respective pairs of electrical contact members.

23. A telecommunications cabling system according to claim 22, wherein the insulating members have a central axis which is parallel to a long axis of the connection module, 25 and the cavities are angled at 45 degrees to the central axis.

24. A telecommunications cabling system according to claim 1, wherein the connection module includes two rows of pairs of insulation displacement contact slots. 30

25. A telecommunications cabling system according to claim 24, wherein the electrical contact members include bifurcated contact arms extending into respective insulation displacement contact slots for electrical connection to the wires of the shielded cable when seated in the insulation displacement contact slots.