Improvements in and relating to electrical connectors

The present invention relates to electrical connectors for making a disconnectable connection.

It is known to provide disconnectable electrical connections by means of plugs and sockets. Where connections for electrical power are concerned, it is important that a first part that is connected to an electrical power supply is arranged so that a user may not make accidental contact with live parts, and such a part is normally called a socket. A second part that is connected to an electrical load that it is desired to power is provided with plug contacts that are arranged to make electrical connection with corresponding socket contacts. Frequently plug contacts are arranged as male plug pins, and socket contacts are arranged as female receptacles. It is frequently important that plugs and sockets are polarised so that it is only possible to make electrical connections between predetermined plug contacts and socket contacts. For low voltage electrical signals, it is also frequently important that the plugs and sockets are polarised, but where the voltage of the electrical signals is low, then it is not necessary to provide protection against accidental contact with live parts. Hence, a lead for inter-connecting a electrical devices may be provided with a plug at each end, each of the electrical devices having an identical socket arranged to receive the plug. Examples of such plug and socket system are the RJ11 and the RJ45 systems.

A disadvantage of known electrical connections for low voltage electrical signals, such as the RJ 11 and the RJ45 systems, is that where it is necessary to provide an intermediate connection between two devices, it is necessary to provide a socket to receive the lead plug. Such sockets may be mounted in a wall plate or in a patch panel or at the end of an extension lead. Sockets are undesirable, since it is difficult to match the impedance of the plugs, and hence signal propagation may be adversely affected and noise created by reflected signals. Sockets such as RJ45 are also undesirable since it is difficult to maintain the separation of the individual plug pin contacts and of the socket contacts to avoid crosstalk between adjacent pairs of contacts. Such crosstalk requires elaborate measures to provide a cancelling signal. Such elaborate measures frequently are only effective over a small frequency range, and hence a socket arranged to operate at a particular frequency may be unsatisfactory at a different frequency.

According to the present invention, there is provided a shielded connector for connecting a telecommunications cable having at least one pair of wires, the connector comprising two connector parts, each having contacts mounted to the connector part so as to mate with a corresponding contact of the other connector part, at least one part being a cable connector part having each contact connected to a terminal for terminating one of the wires, and wherein at least one connector part has shielding around each contact.

A benefit of the connector having shielding around each contact is that a connection between the contacts of the two parts has a much improved immunity to electromagnetic interference.

Preferably the shielding extends between the connector parts when connected.

Preferably shielding is provided in or around the cable connector part.

Preferably the shielding further comprises a metal part arranged to grip the cable.

Preferably the shielding is arranged to be electrically connected to a shielding of the cable.

Preferably the connector has a mating plane about which the two connector parts mate, and a centre perpendicular plane which is perpendicular to the mating plane and intersects the mating plane along a longitudinal centre line of the mating plane, the contacts arranged so that one contact for each of the wires of a pair of wires is on a different side of the centre perpendicular plane.

Preferably the mating plane is stepped, at least one contact being on a different step to another contact, the different steps being parallel planes at a particular step angle to the mating plane.

Preferably the connector is arranged for a telecommunications cable having a plurality of pairs of wires, and wherein the contacts for a particular pair of wires are on the same step.

Preferably the contacts of each connector part are arranged in a substantially rectangular array symmetrically disposed about the centre perpendicular plane, the array comprising a plurality of rows, each row having two contacts, each for terminating one the wires of one pair of wires, each row being arranged on a different step.

Preferably the connector further comprises a metal shield arranged to at least partly enclose one connector part.

Preferably the connector further comprises a conductive plating over at least part of one connector part, the plating arranged to provide shielding.

A benefit of plating is that a separate part is not required for shielding. A further benefit is that a cord grip may be moulded as a portion of a connector housing moulding, so as to make electrical contact with a conductive shielding of a shielded twisted pair telecommunications cable.

Preferably the shielding further comprises additional conductive parts arranged between at least two adjacent contacts within one connector part, the additional conductive parts being electrically connected to the shielding around each contact.

Preferably each connector part is arranged for connection to a telecommunications cable having at least one pair of wires.

Preferably one connector part is arranged for connection to a printed circuit board.

Preferably one connector part is arranged as a socket to receive the other connector part.

Preferably the connection is made by moving the connector parts together along a longitudinal axis of the telecommunications cable when connected as it enters the connector part to which it is terminated.

Preferably the connection is made by moving the connector parts together perpendicular to a longitudinal axis of the telecommunications cable when connected as it enters the connector part to which it is terminated.

Preferably the connection is made by moving the connector parts together along a connection axis, the connection axis being at an connection axis angle to the mating plane such that the respective contacts of each of the connector parts mate as the connector parts are moved together along the connection axis.

Preferably each of the contacts of each of the connector parts is male.

Preferably each of the contacts of each connector part is resilient.

Preferably each of the contacts of the at least one connector part having shielding protrudes the shielding.

Preferably the two connector parts have substantially identical mating faces.

Preferably the step angle is zero (and hence steps form a "sloping" plane coincident or closely parallel to the mating plane).

Preferably the step angle is greater than zero (and hence steps have risers separating them).

Preferably the connexion axis angle is greater than or equal to the step angle (as otherwise the connectors would collide).

Preferably the shielded connector is arranged as an electrical connector part for making a disconnectable connection, the connector part having a longitudinal axis, the connector part further having an array of electrical contacts, the array comprising at least two pairs of contacts arranged so that at least one pair of contacts is in a different plane to another pair of contacts, the planes being parallel to each other and to the longitudinal axis.

A benefit of the electrical connector part having an array of contacts arranged so that at least one pair of contacts is in a different plane to another pair of contacts is that the contacts may be spaced apart from each other, reducing a risk of crosstalk between pairs of contacts.

Preferably the pairs of terminals are arranged so that one terminal is on each side of the longitudinal axis.

A benefit of the terminals being arranged on either side of the longitudinal axis is that when the twisted pair is untwisted, each wire may be easily laced ready for termination with a punch down tool.

Preferably the connection is made between two of the said connector parts.

A benefit of the connection being made between two of the said connector parts is that an installer only has to carry one connector part. A further benefit is that manufacturing costs are also minimised.

Preferably the contacts protrude a mating surface of the connector part.

A benefit of the contacts protruding the mating surface is that they are easy to clean, unlike a female receptacle which requires a shutter to exclude foreign matter when a plug is absent.

Preferably the connection is made by moving the connector part along the longitudinal axis. A benefit of making the connection by moving along a longitudinal axis, is that there is a wiping action as the contacts make, and hence good electrical connection is assured.

Preferably the connection is made by moving the connector part perpendicular to the longitudinal axis.

A benefit of the connection being made by moving the connector part perpendicular to a longitudinal axis, is that an axial strain on the cable is unlikely to disengage the connection.

Preferably the connection is made by moving the connector part along and perpendicular to the longitudinal axis.

A benefit of moving in both longitudinal and perpendicular axes is that good electrical connection may be obtained by having a wiping action as the contacts make, and the connection is not prone to accidental disconnection by pulling on the cable.

Preferably the contacts are spaced in a rectilinear array.

A benefit of an array of contacts is that it is easier to lace a regular array.

Preferably the contacts are symmetrically arranged about a longitudinal axis. A benefit of symmetry is that two identical connector parts will connect together.

Preferably shielding is provided around at least one of the connector parts and extending between the connector parts when connected.

A benefit of shielding is that electrical interference between pairs of conductors is reduced. Hence for network cables, crosstalk may be minimised. A further benefit is that by shielding around the connector part a risk of inducing "alien crosstalk" between adjacent cables is reduced.

In an alternative embodiment the connector part is provided with a shield that is formed by plating the surface of the connector part.

A benefit of having shielding formed on the surface of the connector part is that the shielding is applied during manufacture, and hence the effect is more predictable, and the connector part is easier to use.

In a further alternative embodiment, the connector part is provided with a shield that is a rectangular tubular shape surrounding the connected connector parts.

A benefit of a tubular shield is that it is easy to make, and simple to slip over the mated connector parts. A further benefit is that it provides additional protection against unintentional disconnection of a connected connector. According to a further aspect of the invention there is provided an electrical connector having a cable grip at a cable entry, the cable grip comprising two similar parts arranged to hinge towards the cable so as to trap the cable between the parts.

A benefit of a cable grip trapping the cable is that the grip can be easily manufactured and used.

Preferably the cable grip is arranged to latch in a gripping position.

A benefit of the cable grip latching in a gripping position is that the grip will securely retain the cable.

Preferably the cable grip is arranged to make electrical contact with a conductive shielding layer of the cable.

A benefit of the cable grip making electrical contact is that shielding integrity may be maintained at or adjacent an end of the cable.

According to a yet further aspect of the present invention, there is provided an electrical connector part for making a disconnectable connection with another like connector part, the connectors abutting each other at a mating surface when connected, the connector part having an array of electrical contacts for making the connection, wherein the contacts protrude a mating surface.

A benefit of the contacts protruding the mating surface is that they are easy to clean, unlike a female receptacle which requires a shutter to exclude foreign matter when a plug is absent.

Preferably the contacts are arranged to resile when the connection is made. A benefit of resilient contacts is that a more reliable connection is maintained.

Preferably at least a contact comprises an insulation displacement connector for connecting to a wire.

In an alternative embodiment, preferably at least a contact comprises a screw terminal for connecting to a wire.

In an embodiment of the invention, a preferred connector has connector parts having a stepped hermaphroditic mating profile. ^•

A benefit of the steps is to give vertical and horizontal spacing to reduce crosstalk.-

Preferably shielding is provided on the surface of the steps. A benefit of shielding is that this can be designed so that when one side of the connector is inverted on the other part, gaps in the shielding are filled. In a preferred embodiment the contacts protrude from the shielding to contact their counterparts on the opposite side but are fully enclosed when the two halves of the connector are mated. ^•

Preferably the foil pairs are taken fully into the contact face of the connector part.

A benefit of this is that there is then no need to have a separate shielding shell around the rear of the connector.

Preferably shielding pieces are installed vertically within the volume of a body of the connector part.

A benefit of this is that shielding is not just on the surfaces of the connector part, but effective internally between pairs of wires.

Preferably the shielding is provided with tags to grip the cable braid. ^•

Preferably the connector parts are provided with substantially identical pins, IDC's, shielding and blocks symmetrically on each of the two parts.

A benefit is that this makes it easier to electrically balance the connector when the connector parts are connected. ^•

Preferably the connector part is arranged with angled insulation displacement connectors.

A benefit of this is easier lacing and a reduction of crosstalk. A further benefit is that when one connector side or part is overlaid on a second connector side or part the IDC channels do not allow a straight path for interference from one IDCto a step below on the second connector side.-

Preferably the connector parts are male so the contact pins are always accessible even when the shielding is in place.

A benefit of this is there is no need for a shutter to prevent dirt ingress.

Preferably a connection is made with two identical electrical connector contact arrays.

A benefit of this is both have the same electrical characteristics so it is easier to electrically balance the pair.

Preferably the steps are provided in the shielding between adjacent contacts and adjacent insulation displacement connectors.

A benefit of this is there is good electrical continuity through the shielding because there are multiple faces in abutment.

Preferably all the insulation displacement connectors can be punched down in the same plane. More preferably the insulation displacement connectors are angled to assist in the lacing of the wires and help to minimize crosstalk between the two sides of the connector and within the same side of the connector.

A benefit of this is that when one connector side is overlaid on a second connector side the insulation displacement connector channels do not allow a straight path for interference from one insulation displacement connector to one on a step below on the second connector side.

Specific embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:-

Figure 1 is a perspective view of a first embodiment of a connector part for a shielded electrical connector according to the invention;

Figure 1 A is the same perspective view as shown in Figure 1 , showing a mating plane and a centre perpendicular plane of the connector part;

Figure 2 is a rear perspective view of the electrical connector part shown in Figure 1 ;

Figure 3 is plan view of a flat shield for the electrical connector part shown in Figure 1;

Figure 4 is a front view of an insulation displacement terminal for the electrical connector shown in Figure 1 ;

Figure 4A is a perspective view of the insulation displacement terminal shown in Figure 4;

Figure 4B is a front view of an insulation displacement terminal for the electrical connector shown in Figure 12;

Figure 5 is a perspective view of a second embodiment of the invention similar to the first embodiment, showing the fitting of a shield to a connector part, with a twisted

pair cable omitted from the view;

Figure 5A is a perspective view of the shield and connector part shown in Figure 5;

Figure 5B is a perspective view of the shield and connector part shown in Figure 5 fitted to a twisted pair cable;

Figure 6 is a perspective view showing the method of closing the shield around the connector part;

Figure 7 is a perspective view of two connector parts of a shielded connector of the second embodiment of the invention;

Figure 8 is a perspective view of two connector parts of a third embodiment of the invention, the third embodiment being similar to the first embodiment;

Figure 9 is a perspective view of a connector part according to a fourth embodiment of the invention;

Figure 10 is a perspective view of a connector part according to a fifth embodiment of the invention;

Figure 11 is a perspective view of a connector part according to a sixth embodiment of the invention;

Figure 12 is a perspective view of a connector part according to a seventh embodiment of the invention;

Figure 13 is a perspective view of a connector part according to an eighth embodiment arranged to co-operate with the fourth embodiment of the invention shown in Figure 9; and

Figure 14 is a perspective view of a connector part of a shielded connector of a ninth embodiment of the invention arranged to co-operate with the second embodiment of the invention shown in Figure 7.

From Figure 1 , a perspective view of a first embodiment of an electrical connector part 1 for a shielded electrical connector according to the invention is shown, with a shield 200 (shown in Figure 3) omitted to show details that would otherwise be

hidden. The electrical connector part 1 has an insulating body 100 which is provided with a plurality of contacts 10 to 17 each having a contact face 110 to 117 respectively, the male contact faces are each arranged to protrude a mating surface 2. The mating surface 2 is arranged as discrete steps 3 to 6, each step 3, 4, 5 and 6 comprising a contact plateau 303, 304, 305 and 306 respectively, the adjacent contact plateaus being separated by a riser 313, 314 and 315. The steps each form a separate plane having contacts protruding. At each end of the mating surface, the riser forms an internal end face 312 and an external end face 316. The contacts 10 to 17 are each provided with a insulation displacement terminations 120 to 127 respectively for making an electrical connection to an insulated wire, such as one wire from a pair of a shielded four twisted pair cable 30. The cable 30 is a telecommunications cable, such as a computer network cable, and has a braided shield 31 surrounding foil wrapped twisted pairs 32, 33, 34, and 35, each having two insulated wires 36 and 37 (only two labelled, and not drawn to scale in Figure 1). The insulated wires having conductors suitable for termination at the insulation displacement terminations. The insulation displacement terminations each comprise a wire receiving channel with an insulation displacement terminal and a punch down wire crop surface 129 (only one labelled in Figure 1). The wire receiving channels are at an angle to a central channel 128 for receiving insulated wires of twisted pair wires 32, 33, 34, and 35 which enter the connector part through a cable hole 130 in the end face 312. The foil wrapped twisted pairs are preferably kept twisted and wrapped in foil within the central channel 128. For example insulated wires terminated in terminals 126 and 127, are kept twisted and foil wrapped until they reach intersection 131 where the wire receiving channels for the two terminals meet the central channel 128. The electrical connector part 1 further comprises a pair of retention slots 21 and 22, and a pair of protruding retention angles 23 and 24. At an end of the electrical connector part is a resilient latch 25, which protrudes face 312. The resilient latch having a ramp portion 26 and a latching face 27. Face 312 of the connector part has a latching aperture passing through, and on an external cable end face 318 is a latch abutting face 28. The connector part 1 also has two substantially parallel longitudinal side walls 320 and 321 , at the cable end of which are two vertical grooves 132 and 133 respectively formed between the side walls 320 and 321 and side supports 134 and 135 respectively. At each riser 313, 314 and 315 is provided a groove 138, 139 and 138', 139 ¹ and 138" and 139" respectively, the groove for receiving shielding 290 to provide additional shielding when required between adjacent pairs of contacts. Shielding 290 is inserted into groove 138 by moving in a direction 29D, and when inserted protrudes the surrounding contact plateau 305 so as to make electrical contact with shielding 200 of Figure 3. On each riser, is provided a protrusion 137, 136 and 137', 136' and 137", 136", the protrusions arranged to co-operate with hole in shielding to assist in the retention of the shielding.

Each side wall 320 and 321 has a lower edge 322 and 323 respectively, and the front end face 312 has a lower edge 324 and rear external cable end face 318 has a lower edge 325. Lower edges 322, 323, 324, 325 define the edges of base 326. Base 326 is parallel to a direction 1X. Direction 1X is substantially co-axial with a direction of entry of a cable to the plug. Direction 1X is a longitudinal axis of the connector part 1.

Each of the discrete steps 3, 4, 5 and 6 is at a different height 1M, 1L, 1K and U respectively from the base.

From Figure 1A, which shows the same perspective view of the electrical connector part 1 shown in Figure 1 with the shield 200 omitted, but in this figure drawn to identify a mating plane 1H and a centre vertical plane 1V of the connector part 1. Each contact face 110 to 117 respectively is arranged to mate with a corresponding contact of another connector part, which is provided with contacts that have contact faces that are arranged for electrical connection to the respective contact faces 110 to 117, the connection having a line contact or an area of contact having a centre- Centre lines 1 C, 1 D, 1 E and 1 F pass through the said centre of contact of each pair of contacts 116, 117 and 114, 115 and 112, 113 and 110, 111 respectively. These centre lines 1 C, 1 D, 1 E, and 1 F lie on a mating plane 1 H. In the first embodiment the mating plane 1 H is flat. Between each of the contact pairs, on the mating plane is a centre line 1 G, one the contacts of each pair being on either side of the centre line 1G. A centre vertical plane 1 V which is perpendicular to the plane 1 H, passes through the centre line 1 G.

Hence, when mated with another connector, a corresponding centre line of the other connector part is co-incident with the centre line 1G.

Also shown in Figure 1 A, is the direction 1X, which is a longitudinal axis of the connector part 1 co-axial with a longitudinal axis through a centre of a twisted pair cable as it enters the connector part. A perpendicular axis 1 Y, is perpendicular to the axis 1X. In the first embodiment both the longitudinal axis 1X and the perpendicular axis 1 Y are in the same plane as the centre vertical plane.

The discrete steps 3 to 6 of the mating surface 2 are each arranged so that they extend both above the mating plane 1 H in a direction 1W, and below the mating plane in an opposite direction. In the first embodiment each step 3, 4, 5 and 6 has the respective contact plateau 303, 304, 305 and 306 which is substantially aligned in a plane parallel to longitudinal axis 1X and perpendicular to the centre vertical plane

1 V. Hence the contact plateaus are at an angle 1 R to the mating plane 1 H. At the meeting of each contact plateau 303, 304, 305 and 306 and the respective risers 313, 314 and 315 and external end face 316 are edges 333, 334,335, and 336.

Hence when mated, portions, such as edges 333, 334,335, and 336 of the connector parts protrude the mating plane 1H.

From Figure 2 a rear perspective view of the electrical connector part 1 shown in Figure 1 can be seen to have clips 146, 147 and 148 for retaining a boot on the connector part. The cable hole 130 can be seen to be a large elongated hole, with the narrow dimension being preferably approximately equal to, or slightly less than that of the cable the connector part is intended for use with. The cable hole provides an easy unrestricted access to the central channel 128 for easy feeding of the preferred shielded twisted pairs into the connector part. The connector part also has two clip features 151 and 152 for engaging with slots in a shield 200 shown in Figure 3, which is a plan view of the shield in a flat, unfolded state. Clip features 151 and 152 have abutting faces 153 and 154 which are spaced away from rear face 318 sufficiently to allow for a braided shielding of a cable to be trapped between the shield 200 and the cable end face 318 when the shield 200 is clipped under the clip feature abutting faces 153 and 154.

Shield 200 has a central mating surface 202 which has apertures 210 to 217 for the contacts 10 to 17 respectively to protrude the mating surface so that electrical contact may be made between two plugs when inter-fitted as described with reference to

Figures 7 and 8. Apertures 221 , 222 and 223, 224 are also for the retention slots and retention angles respectively. An aperture 225 is provided to allow the resilient latch to protrude a front face of the shield. An aperture 229 is provided to allow a latch of another plug to engage latching aperture 29. The central plateau areas 203, 204, 205 and 206 are provided with indented fold lines 283 and 284 along either side to permit the side portions 252 to 256 and 242 to 246 to be folded down to cover the sides. Riser portions 232, 233, 234, 235 permit the mating surface to be folded to provide the steps to conform closely with the connector part 1 , when the side portions will closely abut each other, and dovetails 280 (only one labelled for clarity) engages with mating feature 281. Likewise, base portions 262, 262' to 266, 266' fold to engage each other forming an enclosure that will fit snugly to the connector part. To obtain optimum shielding benefit from the shield 200, it is provided with tags 271 and 272 which are arranged to be inserted through slots 132 and 134 and then folded along fold lines 286 and 287 so that holes 273 and 274 may engage and latch under

clips 152 and 151 respectively. Hence braiding contacts 275 and 276 will be forced into the cable braiding making a good electrical contact to provide effective shielding of the connector part, enhancing at high frequencies the performance of the shielded connector when two parts are connected.

Figure 4 and 4A are views of a contact terminal 350 for the shielded electrical connector part shown in Figure 1. Terminal 350 has an insulation displacement terminal 351 comprising insulation piercing blades 352 and 353, with a retention stem 354 to retain the terminal securely to the connector body 100. The contact terminal 350 also has a contact face 360 corresponding to contact faces 110 to 117 visible in Figure 1 , which is connected by a resilient portion 362 to the blade 353. To ensure the position of the contact face 360 is accurately controlled during connection and disconnection of the connector part 1 with a mating connector part, the terminal is also provided with angled support 364 which is arranged to locate in a suitable groove in the connector body 100.

Figure 4B is a view of a contact terminal 380 for the shielded electrical connector part shown in Figure 12. Terminal 380 has a solder post 384 for connection to printed circuit board 988, and has a retention stem 83 to support the terminal within the connector body 963. A length of the stem 383 is such that the contacts may be located in any of the contact locations, and an excess of length may be trimmed either before or after soldering where it protrudes the circuit board. The contact terminal 380 also has a contact face 370 corresponding to contact faces 980 to 987 (only two labelled in Figure 12), which is connected by a resilient portion 372 to the stem 383. To ensure the position of the contact face 370 is accurately controlled during connection and disconnection of the connector part 1 with a mating connector part, the terminal is also provided with angled support 374 which is arranged to locate in a suitable groove in the connector body 963.

Figure 5, 5A and 5B are views of a second embodiment 500 of the invention similar to the first embodiment, showing the fitting of a shield 502 to a connector part 501 , with a twisted pair cable 503 omitted from the view in Figs 5 and 5A. The second embodiment differs from the first in small details, such as the latch arrangement 525, and the cable entry hole which is provided with separators 531, 532 and 533 to further separate twisted pair wires. The separators continue along the central channel, terminating alongside the respective terminations (corresponding to 120 to 127). Cable retaining tags 571 and 572 can be seen both unfolded, and in a folded state, where they are engaged with clips 551 and 552 clamping against the braiding 504 of the shielded cable, securely retaining the cable 503 to the connector part.

Figure 6 is a perspective view of connector part 500 showing that the shield 503 may be easily closed around the connector body by holding the connector part in the hand, and applying pressure in the direction of arrow 6F on the tag 605 by a thumb. To ensure the hole 606 in the tag is securely engaged with the clip 607 on the connector body it is preferable to check the security by applying additional force at this point with a screwdriver before affixing a boot to the connector part covering the tags.

Figure 7 is a perspective view of two connector parts 500 and 500' of the second embodiment of the invention. In use an electrical connection is made between two identical electrical connectors 500 and 500' to provide a shielded connector for connecting a telecommunications cable. Connector parts 500 and 500" are identical or closely similar to that shown and described with reference to Figure 5. Each connector part is connected to one or more wires of a twisted pair cable 503 and 503" respectively as required as shown in Figure 7. Twisted pair cables 503 and 503' are telecommunications cables. Each electrical connector part may be provided with a boot 560 and 560' which is arranged to clip onto the connector body at 561 and 562 to support the respective cable to prevent flexing too close to the plug, and to provide additional strain relief to the cable. To make a disconnectable connection between the wires the two electrical connector parts are brought together so that the mating surfaces 512 and 512' will abut, and in a sliding motion in the direction of arrows 7P and 7Q the protruding retention angles 523 and 524 of one plug are engaged with the corresponding pair of retention slots 521 and 522 of the other plug. As the two plugs are slidably moved together the ramp portion 526 of each resilient latch 525 of each plug engages a corresponding ramp 529 on the other plug resiliently deflecting the latch so that when the end faces 516 abut the corresponding end faces 515' of the other plug, each latching face 527 latches with abutting face 528 of the other connector part.

It is important to note that if it is desired to maintain the correct polarity of the connections through the shielded connector, it is necessary to interchange the wires in a pair of terminals, for example terminal 574 will connect to terminal 576 and 573 will connect to 575.

Figure 8 is a perspective view of two connector parts 801 and 802 of a third embodiment that is similar to the first and second embodiments, differing only in the arrangement of the boot. Figure 8 shows that the shield closely abuts along the mating surface joint line 805 when the two plugs are connected.

Figure 9 is a perspective view of a connector part 700 according to a fourth embodiment of the invention where the mating surface is a continuous surface 705 rather than the stepped surfaces of the other embodiments. Contacts 710 to 717 protrude the mating surface in a similar manner to that described with reference to the other embodiments. A shield 720 may be provided, and as with the other embodiments provides a hole through which the contacts may protrude without touching the shield.

Connector part 700 is arranged for disconnectably connecting with a similar connector part (not shown) to make an electrical connection with at least one part, connector part 700, being connected to at least one pair of wires of a telecommunications data cable.

From Figure 9 a mating plane 7H and a centre vertical plane 7V of the connector part 700 is also shown. Each contact face 710 to 717 respectively is arranged to mate with a corresponding contact of another connector part, which is provided with contacts that have contact faces that are arranged for electrical connection to the respective contact faces 710 to 717, the connection having a line contact or an area of contact having a centre, through which centre lines 7C, 7D, 7E and 7F pass through the said centre of contact of each pair of contacts 716, 717 and 714, 715 and 712, 713 and 710, 711 respectively. These centre lines 7C, 7D, 7E, and 7F lie on the mating plane 7H. Between each of the contact pairs, on the mating plane is a centre line 7G, one the contacts of each pair being on either side of the centre line 7G. A centre vertical plane 7V which is perpendicular to the plane 7H, passes through the centre line 7G.

Hence, when mated with another connector, a corresponding centre line of the other connector part is co-incident with the centre line 7G.

Also shown in Figure 7 is the direction 7X, which is a longitudinal axis of a centre-line of the cable entering the connector part 700. When two corresponding connectors according to this embodiment are mated, they are moved together, substantially along the centre line 7G, which being at an angle to the centre line 7G, means that the mating planes move together, and as the connectors reach their fully mated position, the respective contacts touch their opposite contact, and are forced to resile. Hence, both a slight rubbing action and a contact pressure ensure good electrical connections are made.

Figure 10 is a perspective view of a connector part 900 according to a fifth embodiment of the invention, similar to the other embodiments described herein, except that the engagement of two such connector parts or plugs is in a perpendicular direction of arrow 9V. The perpendicular direction is at a angle such that there is little or no relative sliding movement along the mating plane between the connector parts when being connected. Hence the slots and engaging angles of the first embodiment are replaced with locating pegs 902, 903 and locating sockets 904 and 905. Vertical clips 910 and 911 are provided to maintain engagement of two plugs when fitted together. The perpendicular direction 9V is substantially perpendicular to a longitudinal axis of a telecommunications cable as it enters the connector part 900.

International Standards relating to telecommunication cables and equipment that are relevant for shielded connectors according the present invention specify a bandwidth for operation. These are commonly referred to as:-

CAT5E having a data transfer rate of 1Gbit/sec and a 100Mhz bandwidth CAT6 having a data transfer rate of 1Gbit/sec and a 250MHz bandwidth CAT6A having a data transfer rate of 10Gbit/sec and a 500Mhz bandwidth

Preferably an embodiment of a shielded connector according to the present invention is suited for use at frequencies of 10OMhz.

More preferably an embodiment of a shielded connector according to the present invention is suited for use at frequencies of 250Mhz.

Yet more preferably an embodiment of a shielded connector according to the present invention is suited for use at frequencies of 500Mhz. An embodiment of a shielded connector according to the present invention has shown up to 14dB better worst case pair NEXT (near end cross talk) performance on a network analyser 'pyramid' test compared to a known mated RJ45 10G connector pair. This is a significant improvement, and provides an advantage to system designers and installers in permitting longer cable runs at higher effective data transfer rates.

To connect a shielded twisted pair cable to a connector part according to the invention, such as connector part 1 shown in Figure 1 , a boot (such as boot 560) would first be placed on a cut end of a cable (503). An outer sheath of the cable would be cut back and removed for a length slightly greater than a length of the connector part. The braided shielding is then rolled up near the end of the cable, leaving the four pairs of wires still wrapped in their foil shield.

The pairs are then stacked on top of each other and fed into the hole 130 in the rear of the connector body 100.

The foil is removed from the top pair of wires and they are un-twisted sufficiently to lace into the terminations, where they are punched down using a standard tool to keep the cable in the plug.

Going along the connector part or plug, the rest of the pairs of wires are similarly terminated.

When using the punch down tool, the terminals are positioned such that the wires are cut off back from the front of the step, so that the wire is clear of the shielding, ensuring that there is no possibility of shorting the wire.

The formed up box shape of shielding is then slid onto the plug, with the tags being fed through the slots 132, 133 at the rear of the connector body 100.

The tags are then folded over onto the braid firmly retaining the cable to the connector. The engagement of the tags with the clips is verified with a screwdriver or similar tool, and then the boot is slid over the end of the wire and clipped onto the connector body to complete the connection of the connector to a cable.

An embodiment of a shielded electrical connector for connecting telecommunications cables has an electrical connector part formed from an insulating block, with a self- interlocking profile consisting of preferably at least two steps. On the face of each step is at least one electrical contact. This embodiment has two contacts on each step. Each pair of contacts is symmetrical with the centre line. When the steps mate with their identical counterpart, electrical continuity between the said contacts is achieved. The stepped system increases the distance between adjacent IDC's and contacts, reducing crosstalk. When the two sides or parts of the shielded connector are mated, the contacts and IDC's are not open to air further reducing possible crosstalk; i.e. there is another barrier-surface between the critical areas. The shielding is around each contact.

The stepped system allows the IDC's to be spaced apart horizontally and vertically yet still punched-down with a punch-down tool held substantially in the same vertical plane. The steps allow the pairs / foils to terminate within the contact face, each pair positioned on a unique horizontal plane. This minimizes the occurrence of crosstalk between the pairs. The foil on each pair can be maintained until it passes beyond the termination position of the previous pair. The steps also allow unrelated contacts to be positioned on a similar vertical plane without physically coinciding with each other during connection when using a sliding horizontal motion.

It is preferred that the two parts or sides of the shielded connector slide together lengthways and horizontally. It is further preferred that the two sides are located by at least one rail and slot. It is also preferred that at least one sledge on the connector side interacts with a slot on the other side. It is particularly preferred that the stepped area of the connector part has at least one area of shielding to enhance the reduction of crosstalk by screening critical parts of the connector from one another. It is preferred that this shielding abuts with the shielding on the mating connector part to achieve electrical continuity between the shielding on the two sides or parts of the connector, that is through the shielded connector.

In a particular embodiment it is especially preferred that the shielding slides on after termination, covering both the insulation displacement connectors (IDC's) and the conductors leading from the IDC's to the contacts. It is particularly preferred that the shielding has a profile matching that of the steps of the connector. In this embodiment the shielding will have multiple faces. These will give good electrical continuity when the faces are in contact with one another across the two sides or parts of the shielded connector. The different steps within the profile of the shielding also establish multiple 'ground planes' within the vicinity of the connector. When the connector pair is mated the shielding between the mating faces is of double thickness, increasing the shielding effect. The shielding also forms a hard resistant protective surface for connection.

A further enhancement uses plates positioned substantially vertically with respect to the IDC channels within the volume of the block to shield the bottom of an IDC from the adjacent pin /IDC on the same side of the connector. It is preferred that the shielding has lugs that locate through the block and tags that can be folded back to impinge on the cable- braid to achieve electrical continuity between the cable screen / braid and the connector shielding. The tags help to achieve 360 degree shielding. They also assist in clamping the cable.

It is further preferred that the block has angled IDC's to assist in lacing the wires and to reduce the overall length of the connector. The angled paths also reduce crosstalk because they prevent an open pathway between one set of IDC's /contacts and that of a different wire-pair both on the same side or part of the connector and between those on one side or part and the other part.

The shielding is preferably tin plated brass, although other electrically conductive materials would be acceptable.

The different levels of shielding of a stepped shielding, helps dissipate internal signal reflections within the body of a mated shielded connector.

A further embodiment, is similar to the first embodiment, apart from shielding is provided by using a conductive plastics material for the body of the connector. In this embodiment, it is necessary to provide an insulation between the conductive body and the contacts so that the terminations are electrically isolated from the body.

A yet further embodiment, is similar to the first embodiment, apart from shielding is provided by using a plastics material with inherent shielding properties for the body of the connector. In this embodiment, it may necessary to provide an insulation between the conductive body and the contacts so that the terminations are adequately electrically isolated from the body.

From Figure 11 a perspective view of a connector 930 according to a sixth embodiment of the invention. Connector 930 is arranged as a panel mounting socket 931 with a frontplate 910 having a rear face 911 for abutting a mounting surface (not shown), and a body 912 arranged for insertion into an aperture in the mounting surface. A resilient latch 913 is arranged to retain the socket to the mounting surface. The socket 931 may be provided with means for termination of a twisted pair cable such as cable 932, the means for termination including support means such as cable boot 933.

An advantage of the socket 931 being arranged for connection to a cable is that it is relatively easy to matched an impedance of a cable connector part such as cable connector part 500 or 500' of the second embodiment shown in Figure 7, since identical cables and an identical method of termination of the wires to the terminals may be used.

Figure 12 shows a further embodiment 960, similar to the connector 930, having a socket 961 provided with connections from the contacts to a printed circuit board 962. A benefit of such an arrangement is where it is desired to incorporate the socket 961 into other electronic equipment. A connector part 500 will equally connect to socket 961 as to a connector 500'. Hence a flexibility of a system may be enhanced by using a common mating interface across a range of connectors.

To facilitate the removal of a connector part 500 from a socket 931 or 961, a latch corresponding to ramp 529 and abutting face 528 are omitted, and a open slot 934 is provided instead. To enable the connector part 500 to be latchably retained to the socket 931 , 961 a resilient latch 935 protrudes the frontplate so as to co-operate with abutting face 529 of a connector part 500 inserted into the socket 931 , 961.

The socket 931 having body 912 is arranged to receive a connector 501 when a cable has been terminated to the contacts, in a similar manner to how the connector 501 is received by the shield 502 in the second embodiment. To provide the electrically conductive shielding body 912 may be a metal die cast part, or may be a plated plastics moulding.

In the arrangement of socket 961, the body 963 has a faceplate 970 having a receiving portion 971 for receiving a connector part 500. The body 963 provides locations for contacts 380 (Figure 4) of which one pair are contacts 986, 987. The contacts are arranged to be electrically connected to circuit board 988, and shielding is preferably provided by a conductive surface 989 over the body 963. The conductive surface may be a plated surface, or a formed metal component that is fitted over the body. In the arrangement of socket 961 , a mating surface 990 may preferably be unshielded, and formed as a part of a plastics moulding including the frontplate 961 and the body 963.

To ensure electrical continuity with a shielding on a connector part when connected to the socket, a continuity contact 991 is provided which is electrically connected to a suitable "earth" connection.

Socket 931 and socket 961 are connector parts.

Figure 13 is a perspective view of a connector part according to an eighth embodiment 730 of the invention arranged to co-operate with the fourth embodiment 700 shown in Figure 9. The connector 730 is similar to connector 700 apart from having fewer contacts. Connector 730 has six insulated pads 740, 741 , 742, 743, 744 and 745 and two contacts 746 and 747, which are arranged to co-operate with contacts 710 to 717 respectively of the connector 700. Hence when the connector 700 and 730 are connected, only one pair of wires is electrically connected through the connectors.

Such a connector is useful where it is desired to only connect two wires, such as where a low frequency analogue signal, such telephone apparatus is required to be connected to a cabling system using connectors 700.

Connector 730 has a centre line 73G and a mating plane 73H and a vertical perpendicular plane 73V. When mated with a connector 700, the centre line 73G is co-incident with centre line 7G.

Figure 14 is a perspective view of a connector part of a shielded connector of a ninth embodiment 500" of the invention arranged to co-operate with the second embodiment 500 shown in Figure 7. Connector 500" has two pairs of contacts 510" and 511", and 575" and 576", and four insulated pads, such that when mated with a connector 500, only two pairs of wires are connected through the connectors. Otherwise the connector 500" is identical to connector 500, (and like numbered items are identified with a ").