GB2362041A

GB2362041A - Electrical connector system with data handling facility

Info

Publication number: GB2362041A
Application number: GB0110714A
Authority: GB
Inventors: John Francis O'sullivan; John Appleton
Original assignee: HAGER Ltd
Current assignee: HAGER Ltd
Priority date: 2000-05-03
Filing date: 2001-05-02
Publication date: 2001-11-07
Also published as: GB0110714D0; GB0010517D0

Abstract

An electrical connector system comprises a male part and a female part in which each part is provided with a set of data handling terminals with which data handling conductors can be engaged, the data handling terminals having respective data handling contacts 36 and being so arranged that, on coupling the male and female parts together, the data handling contacts 36 of one set register with those of the other set. Various implementations of the data handling contacts/terminals are disclosed. The male and female parts also comprise power contacts 14N for electrical supply to an electrical appliance. In use the connector system is able to control the ON/OFF junction and dimming function of a fluorescent light.

Description

1 2362041 ELECTRICAL CONNECTOR SYSTEM This invention relates to an

electrical connector system particularly for use in mains electricity supplies in industrial, office and domestic applications, e.g. fluorescent lighting.

The electrical connector system of the present invention is a development of the system disclosed in our prior European Patent No. 0 125 86 1, the entire disclosure of which is incorporated herein by this reference.

The system of EP-B-0 125 861 is in commercial use, components of the system being sold under the Registered Trade Mark KLIK. The system may be defined in the following terms, namely an electrical connector system comprising:

a female part having electrical supply terminals with related electrical power handling contacts located on an internal face of a wall of the female part, the wall having entry apertures which are offset from the contacts; and a male part having projecting electrical power handling contacts for insertion through the entry apertures of the female part and into offset relation with the contacts of the female part; the two parts being movable relative to one another in a direction which is transverse to the direction of insertion so as to engage the contacts of the male part mechanically and electrically with the contacts of the female part.

The present invention seeks to provide an electrical connector system as defined with the facility to handle data-carrying conductors, e.g. for the digital control of fluorescent discharge lighting.

According to the present invention there is provided an electrical connector system as defined in which each part is provided with a set of data handling terminals with which data handling conductors can be engaged, the data handling terminals having respective data handling contacts and being so arranged that, on coupling the male and female parts together, the data handling contacts of one set register with those of the other set.

The invention has particular application to the type of connector system comprising three power handling terminals, namely live (line), neutral and earth terminals, especially connectors in which the power handling terminals all lie substantially wholly within a zone circumscribed by an imaginary circle consistent with the dimensions prescribed by B.S. 4662 Amendment 3 Fig 6 (Electrical accessory architrave box: size 1) and B.S. 4568 Part 2 1970 Amendment 3 referring to "Steel conduit and fittings with metric threads of ISO form for electrical installations Part 2, Fittings and components" - informally referred to a B.E.S.A Boxes. Typically the imaginary circle will have a diameter no greater than 60 mm and more usually no greater than about 53 mm.

Preferably the data handling terminals of at least one of the connector parts likewise lie within the imaginary circle as referred to in the preceding paragraph.

The data handling contacts/terminals may be used for digital data handling, e.g. according to a digital control protocol such as DALI (Digital Addressable Lighting Interface) which is a control protocol for the ON/OFF and dimming of fluorescent discharge lighting.

The arrangement may be such that the two sets of data handling contacts register with each other on insertion of the power handling contacts of the male part through the entry apertures of the female part. Alternatively the arrangement may be such that the two sets only register after the two parts have been adjusted in the transverse direction to mechanically and electrically engage their respective power handling contacts.

The power handling terminals of the two parts are typically of the screw clamp type and the data handling terminals/contacts may be so arranged that they do not impede access to the screws of the power handling terminals; however we do not exclude the possibility that at least one of the data handling terminals/contacts is arranged for movement between a normal position of use and a position allowing access to said screws associated with one or more of the power handling terminals. Moreover, we do not exclude the possibility of the power and/or data handling conductors being permanently wired, e.g. as by soldering or crimping, to the terminals of the male part so that the male part is effectively non-rewirable (at least not without the aid of special tools or soldering equipment for instance).

The screw-clamp type portions of the power handling terminals may each comprise a block formed with a bore for reception of an electrical power conductor and the associated screw may be adjustable inwardly and outwardly of the bore in a direction transverse to the bore so as to clamp an inserted conductor within the bore.

Typically the male part is of elongate shape having a minor axis and a major axis, the power handling terminals of the male part being arranged with the live and neutral terminals spaced laterally relative to the major axis. In such an arrangement, the clamping screws are usually arranged for adjustment in a direction substantially parallel with the major axis and their tool-engageable heads are both presented towards one end of the male part so that both screws can be accessed from the same side in order to facilitate wiring of the male part.

Where the one of the parts is to be provided with a set of data handling terminals, this gives rise to a problem of location of the same without impeding access to the live and neutral power handling terminals.

Accordingly the data handling terminals associated with the male part may comprise projecting blades which are located in a zone lying between the heads of the clamping screws and said one end of the male part, the blades being positioned and oriented so as to be clear of the approach path of a screw-driving tool as the latter is brought into engagement with each of the screw heads associated with the live and neutral terminals.

The blades may be provided with V-shaped entries for reception of conductors.

The blades may be arranged with their major faces extending substantially parallel to the direction of screw travel and they may be offset from each other in such direction and/or perpendicular to such direction..

Alternatively the blades may be arranged one behind the other in the direction of screw travel.

The data handling terminals may be located outboard of the power handling terminals.

The data handling terminals of the male part may be located at a different level relative to adjacent power handling terminals so that access to the power handling terminals can be obtained by passage of a tool over or beneath the data handling terminals.

The data terminals of the male part may be located outboard of the power handling terminals in an in-line arrangement, the axis of which passes between power handling terminals of the male part so that tool access to the latter can be obtained at either side of the in-line arrangement.

The data handling terminals of the male part are conveniently coupled to their counterparts of the female part through a strain relief projection which holds the male part captive to the female part when the two parts have been assembled with electrical continuity between their respective sets of power handling terminals.

The strain relief projection may be formed by the data handling contacts and may comprise an outwardly projecting portion which is generally Tshaped in crosssection.

The strain relief projection may comprise a pair of conductive sections separated by a central insulating section. The conductive sections may comprise extrusions of conductive material such as brass.

The strain relief Projection may be located in fixed position relative to the base of the male part by clip means which may be integral with the base.

In one embodiment of the female part, the live and neutral power handling terminals may be located in laterally extending housing sections while the corresponding power handling contacts are located in a central housing section. In this embodiment, the data terminals and their associated contacts may also be located in the central housing section.

In another embodiment of the female part, the data handling terminals are located in a central zone located inboard of the power handling terminals.

The data handling contacts may be located outboard of the live and neutral 5 terminals and electrically connected to the inboard data handling terminals.

The data handling terminals and contacts may be carried on an insert which can be fitted to a housing of the female part which accommodates the power handling terminals.

The data handling terminals may comprise cantilevered elements cooperating with respective fixed contacts so that data conductors can be inserted between the free end of each cantilevered element and the associated fixed contact.

Entries for insertion of the data conductors may be located inboard of entries for insertion of the power handling conductors.

The invention also encompasses, as separate entities, the plug part and the socket part of an assembly as defined hereinabove.

The invention will now be described by way of example only with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of an electrical connector system in accordance with 25 the invention; Figure 2 is a perspective view, partly cut-away, of one form of plug for use in the system of Figure 1; Figure 3 is an enlarged detail view showing the data pin assembly of the plug; Figure 4 is an exploded perspective view of the data pin assembly of Figure 4; Figure 5 is an exploded perspective view, partly cut-away, of the plug; Figure 6 is a diagrammatic view of a male connector having a modified data terminal unit; Figure 7 is a perspective view of a male connector having another modified data terminal arrangement, some parts being cut away or removed for clarity; Figure 8 is an enlarged diagrammatic view of the modified data contact terminal arrangement of Figure 7; Figure 9 is a perspective view of the modified data contact terminal arrangement of Figure 7, seen from the opposite side; Figure 10 is perspective view of the socket, seen from the opposite side relative to 20 the view of Figure 1; Figure 11 is a similar view to that of Figure 10 with the back plate of the terminal housing removed; Figure 12 is a plan view of the socket of Figures 10 and 11; Figure 13 is a perspective view showing the assembly of the plug and socket, one half of the socket being removed for clarity; Figure 14 is a side view of the plug and socket assembly; Figure 15 is plan view of a modified socket; Figure 16 is a side view of the modified socket show assembled to the plug; Figure 17 is a perspective view of the assembled plug and socket of Figure 16 with one half of the socket removed for clarity; Figure 18 is a perspective view on an enlarged scale of an insert forming part of the socket shown in Figures 15 to 17; Figures 19 to 22 are fragmentary perspective views of various embodiments of nonrewirable plugs; Figure 23 is a perspective view of another embodiment of the plug; Figure 24 is an enlarged perspective view of a pair of integral data handling terminal and data contact members which form the strain relief projection; Figure 25 is a similar view to that of Figure 24 but showing modified data handling terminal and data contact members which may be employed in the embodiment of Figure 23 in place of the terminal/contact members illustrated therein; Figure 26 is an exploded perspective view of another embodiment of socket; and Figure 27 is an enlarged perspective view of an insert forming part of the socket of Figure 26.

The system of the present invention may be generally the same as those described in European Patent No. 0125861 in which the electrical contact between the male and female parts is effected in a two stage sequence involving initially inserting the male part into the female part and then sliding the parts relative to one another in a direction transverse to the insertion direction so as to register the contacts of the male connector or plug with those of the female connector or socket. As a detailed description of the design and construction of the connector system is given in the prior patent, the description herein will focus on the modifications introduced by the present invention; the reader is referred to the prior patent for details that are not given here. In the drawings, the same reference numerals are used in relation to different embodiments where such embodiments incorporate similar components.

Referring to Figures I to 5, the plug comprises a base 10 from the exterior face of which the power handling contacts project. The base 10 is provided with a removable cover 12 which may be snap fitted or otherwise to secured, e.g. by self-tapping screw 13, to the base to form a housing concealing the bared ends of wiring and electrical terminals. In Figure 2 only the live external contact 14L is illustrated but, as will be apparent from Figure 5, there are also neutral and earth contacts 14N and 14E projecting from the base 10, all three contacts lying at the apices of an isosceles triangle. Each power handling contact 14L, 14N and 14E is electrically connected through the base 10 to a respective terminal block accommodated within respective wells 16, 18 and 20 at the interior face of the base 10. The live, neutral and earth terminal blocks are depicted in Figures 2 and 3 by reference numerals 22L, 22N and 22E; the earth terininal block as illustrated is integrally formed with the earth contact 14E which is of inverted T-shaped configuration. The "live" and "neutral" wells 16, 18 extend alongside one another approximately midway between the front and rear ends of the base (as viewed in Figures 2 and 3) while the "earth" well 20 extends centrally of the base from a location rearwardly of the wells 16, 18 to the rear end of the base.

Each terminal block is formed with a bore 26, the axis of which extends generally normal to the interior face of the base, and is provided with a screw-operated clamp screwthreadedly engaged in a transverse bore so that the inner end of the screw can be used to clamp the bared end of an electrical conductor within the terminal block and thereby obtain electrical continuity between the conductor, the terminal block and the associated external contact. As is usual, each clamping screw terminates at its outer end in a head 28 provided with a formation, e.g. a slot, for co-operation with a tool such as a screw driver. Each well 16, 18, 20 is produced with cut-away access opening 30 at one end to provide for screw driver access. It will be noted that the screw heads associated with the live and neutral terminal blocks 22L, 22N are presented towards the forward end of the base so that screw driver access can be had to both without excessive manipulation of the connector during wiring. Access to the earth terminal block is obtained from the rear end of the base.

In addition to the live, neutral and earth contacts, a further projection 34 also extends from the base 10, as in the design described in the prior patent. This projection affords strain relief in use. The lower part of the projection is of inverted T-shape having a stem 34A and a crosspiece 34B, the arrangement being such that when the projection is engaged with the socket following insertion of the plug and linear sliding thereof to engage the power handling terminals, the projection 34 is held captive to the socket by the crosspiece 34A thereby affording strain relief to the electrical interconnections. In the present invention, in addition to the strain relief function, the projection 34 serves as a carrier for a pair of electrical contacts 36 (one only shown in Figure 1) for digital data transmission and for this purpose the contacts 36 will typically handle low voltages ranging for instance from 0 volts to about 10 volts.

The contacts 36 are in the form of generally J-shaped strips of conductive material which extend from a location inboard of the base 10, along opposite sides of the stem 34A and through apertures in the crosspiece 34B where they are folded over at their outboard ends so as to extend to and around opposite ends of the crosspiece 34B. The contacts are spaced apart from each other by the material of the projection which is non conductive so as to electrically isolate the data contacts from each other. The inboard ends of the data contacts are electrically connected to respective data terminals 38 through conductive tracks (not shown) on a printed circuit board 40 provided on the interior face of the base. The printed circuit board may be permanently affixed to the base, for instance by means of integrally moulded rivets or by adhesive. The strain relief projection 34 may be attached to the circuit board 40 and project through an aperture 41 in the base 10 (see Figure 5).

The data terminals 38 are located in the zone lying outboard of the adjacent power handling terminals, viz. between the forward end of the base 10 and the wells 16, 18 and are in the form of blades formed with generally V-shaped slots 42 into which the bared ends of digital data conductors may be pressed to secure them and thereby obtain electrical continuity with the data contacts 36. The V-shaped configuration of the slots 42 allows conductors of different gauges to be accommodated. If desired, the terminals 38 may be designed so as to cut into the insulating sheath surrounding the conductive cores to effect electrical contact with the latter thereby obviating the need to bare the data conductors during the wiring procedure. The data terminals 3 8 are oriented in planes which are substantially parallel with the direction of travel of the screws associated with the live and neutral terminal blocks 22L, 22N and are offset so that access to the screw heads 28 is not impeded, at least not to any significant extent. More specifically, the terminals 38 are located within a zone lying between the axes of the clamping screws 28. Depending on the space available, they may be aligned with one another in the direction of elongation of the plug or, as illustrated, they may be offset from one another in that direction. The sheathed data conductors may be wired so that the bared ends thereof project into the space lying between the terminals 38 or they may project outwardly of the terminals in which case the sheathed conductors may be forced to the floor of the printed circuit board recess to permit screw driver access to the screw heads associated with the live and neutral terminal blocks 22L and 22N.

The base 10 is also provided with a cable clamp 44 with flexible, spaced apart gripping arms 45 defining a cable receiving slot located in registry with entrance opening 46 in the cover 12. The cover 12 is provided with serrated sections 47 on opposite side walls thereof to facilitate gripping during plug insertion and sliding.

In an alternative embodiment the data handling terminals of the male part are located outboard of adjacent power handling terminals and are disposed at a different level so that access to the power handling terminals can be obtained by passage of a tool over or beneath the data handling terminals. This is exemplified in Figure 6. In this example the plug may be similar to the plug as shown in Figure 1 except for the design of the data pin and associated contacts and terminals. The strain relief Projection 34 is carried by, and may be integrally moulded with, an insert 50 which is secured in place on the base 10 for example by integrally moulded clips (not shown) on the base co-operating with the insert 50. The insert 50 has a central narrow section 70 thereof passing through an aperture 52 in the base 10 and a wider central section 7 1 which seats on the interior face of the base.

An enlarged portion 54 of the insert 50 is spaced above the base 10 to leave gaps sufficiently large to allow screw driver access to the screw heads 28 of the live and neutral terminals.

As in the embodiment of Figures 1 to 5, the projection 34 serves to locate generally J-shaped data contacts 36. In the embodiment of Figure 6, the data terminals 56 are of generally S-shaped configuration and are located in recesses 58 in the insert 50 with one end of the contact received in channel 60 for reception of the bared end 62 of a data conductor 64, the channel being provided with cable gripping formations 66. The bared ends 62 of the data conductors are wired up by trapping them between the arcuate formations 68 of the terminals 56 and the outer walls 60A of the channels 60. Relative to the embodiment illustrated in Figure 2, the insert of the Figure 6 embodiment is located between the wells 16, 18 and the forward end of the base 10.

In a further embodiment, the data terminals of the plug may be located outboard of adjacent power handling terminals in an in-line arrangement, the axis of which passes between the power handling terminals so that tool access to the latter can be obtained at either side of the in-line arrangement. This is exemplified in the embodiment of Figures 7 to 9 which is similar to that of Figures 2 to 5 except for the arrangement of the strain relief projection and the data terminals and contacts. In this embodiment the data terminals are again located in the zone lying between the wells 16, 18 and the front end of the base 10 and are located one behind the other so that one terminal 80 is adjacent the front end of the base 10 (as seen in Figure 7) while the other terminal 82 is located adjacent the wells 16, 18. Both terminals are carried by a centrally located housing 84 which extends from the wells 16, 18 to the front of the base and may have a width such that screw driver access, via the openings 30, to the screw heads associated with the live and neutral terminals is not impeded.

The housing 84 may be held in a fixed position on the base by suitable clips (not shown). The forward data terminal 80 is accommodated in a recess 87 and comprises a springy tongue 88 formed by one limb of a first U-shaped portion, the second limb 90 of which is integral with a second U-shaped portion 92 having a limb 94A which extends around the front end of the housing 84 and beneath the underside of the housing 84 for engagement with a respective upper end 36A of the data contacts 36 carried by the projection 34. The bared end 95 of a data conductor 97 is in use trapped between the first and second limbs of the first U-shaped portion by adjustment of clamping screw 96 engaged in an upper wall section of the housing.

As best seen in Figure 9, the rear data terminal 82 is located in a recess 102 which faces the opposite direction to recess 87. The terminal 82 is of similar configuration to terminal 80 except that the second U-shaped portion will be substantially longer (see connecting limb 103) so as to extend to and wrap around to the underside of the front of the housing for engagement with the upper 36B of the corresponding data contact 36. Also the first U-shaped portion of the rear data tenninal 82 is reversed with respect to the front terminal so that the corresponding data conductor is introduced from the opposite side of the housing for clamping by screw 104. The arrangement is such that, when the data conductors are wired up to the data terminals 80, 82, they are located in close proximity to the base so as to afford sufficient overhead clearance for screw driver access to the screw heads 28 of the live and neutral terminals.

It will be noted that each of the plug embodiments described above is of a compact design; in practice, the designs exemplified allow the power handling terminals and the data terminals and their associated contacts to be accommodated within a circumscribing circle consistent with the dimensions prescribed in the previously mentioned British Standards, e.g. no greater than 60 min in diameter, typically no greater than about 53 mm.

The embodiments described above are all intended for wiring and rewiring by a user. However, in some cases, a so-called non-rewirable plug may be desired, i.e. one which is initially permanently wired by the plug supplier, e.g. by soldering or crimping the power handling and/or data handling conductors to the corresponding terminals of the plug. In this case, a plug according to the present invention may be provided with power handling and/or data handling terminals/contacts appropriately adapted for permanent connection to the power and data conductors and so arranged that they are all circumscribed by an imaginary circle as mentioned above.

The plug embodiments thus far described, including non-rewirable embodiments, may all be used with any one of the socket embodiments to be described below.

The socket is depicted by reference 120 in Figure I and in one embodiment, as shown in Figures 10 to 14, the socket 120 comprises a circular base plate 122 formed with an annular rim 126 and radially elongated apertures 128 suitably located at diametrally opposite positions for registry with tapped screw/bolt receiving holes of a standard B.E.S.A. box as previously mentioned. On its rear face, the base plate 122 is fon-ned with bosses 13 0 lying within the circumference of the rim 126. The power handling and data handling terminals are also located within the confines of the rim 126 and are accommodated in a housing comprising a central section 134 and side arms 136. As in the case of the plug design, the power and data handling terminal arrangement is located within an imaginary circumscribing circle as previously mentioned.

The earth terminal 138 is received with a well 140 and comprises a screw clamp-type terminal block 142 having a screw head 144 and is connected to a spring contact 146 for co-operation with the earth contact of the plug when the latter has been inserted and displaced linearly relative to the socket in the manner described previously.

Alongside the earth terminal 138 there is a well 148 for fitting of a loop-in terminal (not shown) when required. Spaced from the earth terminal are the live and neutral terminals 150L, 150N respectively which are accommodated in wells 152, 154 formed by the side arms 136 of the housing and each comprising a terminal block 156L, N and associated clamping screws 158L, 158N. Screw driver access openings 174 are provided in the housing at strategic locations in registry with the screw heads 144 and 158L, N.

The live and neutral contacts 14L, 14N of the plug pass through slots 160, 162 in the base plate 122 which open into wells 162, 164 accommodating spring contacts 166L, N which are connected electrically to the terminal blocks 156L, N respectively, the arrangement being such that, on initial insertion through the slots 160, 162, the L-shaped plug contacts 14L, N are offset from spring contacts 166L, N but are brought into engagement with the same on sliding the plug in a direction away from the earth terminal 138. The plug earth terminal 168 will be seen in Figures 13 and 14 which enters through opening 170 in the base plate 122 for engagement with the terminal 146.

The socket is provided with a pair of data terminal/contact sets in that part of the housing 134 which is diametrally opposite the housing section accommodating the earth terminal 13 8. The data terminals 180 are each received within a well 182 located one on each side of the central longitudinal axis of the housing 134, the wells 182 each being provided with a screw driver access opening 183 and being separated by a centrally located well 186. Each data terminal comprises a terminal block 188 provided with a clamping screw 190 and each terminal block 188 is connected electrically to a respective spring contact 192 accommodated in the central well 186. The central well 186 is provided with an entry aperture 196 passing through the base plate 122 for reception of the plug projection 34, each spring contact 192 being located for engagement with respective ones of the data contacts 36 of the plug when the latter is inserted into the socket. Thus, when the plug is assembled to the socket, continuity is obtained between the power handling terminals and data handling terminals of both components. It will be observed that all of the power handling and data handling

terminals of the socket are all located within a circle centred on the centre of the base plate 122 and passing centrally through the apertures. The housing includes a back plate 198 provided with apertures 199 which register with the bores in the various terminal blocks to allow insertion of power and data conductors, clamping being effected by the screws which are accessible from the sides of the housing 134.

The embodiment of Figures 15 to 18 comprises an especially compact design.

Those parts which are generally the same as parts which are shown in the embodiment of Figures 10 to 14 are depicted by the same reference numerals. In contrast with Figures 10 to 14, in this embodiment the live and neutral terminals are accommodated in wells 200 whose axes extend generally parallel with the central housing 206, access to the screws 158L, N being afforded by access openings 174. The live and neutral terminals 156L, N are connected electrically to spring contacts 166L similar to those illustrated in Figures 10 to 14 and accommodated in wells 162.

The data terminals of the socket are located in a central well 212 which extends from a point adjacent the well 140 for the earth terminal and between the wells accommodating the live and neutral terminal blocks 156L, N. The data terminals are mounted on an insert 214 which has cavities 215 which extend side by side and each receive a respective data terminal in the form of a springy cantilevered blade 2 10 which is anchored at one end 216 and projects beneath and contacts an inwardly directed projection 2 18. At its free end, the blade 2 10 is proximate or may engage with a contact strip 220 which runs from cavity 215 along an arm portion 216 of the inser-t 214 and terminates in a springy contact 222 for engagement with a respective plug contact 36. The springy contacts 222 flex when engaged by the plug contacts 36 and serve to bias the cross-piece of the "T" towards the base 10 so as to bear against the inner surface of the base of the socket when the plug has been coupled with the socket by insertion and sliding.

Access to each cavity 215 for the purposes of wiring a data conductor is obtained through openings 224 each in registry with the free end portion of a respective terminal blade 210. Further openings 226 are provided for access to that portion of each terminal blade which is adjacent its cantilever mounting. The openings 226 permit the insertion of a tool so that the blade can be flexed away from the strip 220 to facilitate insertion or removal of the data conductor. On removal of the tool, the blade flexes back towards the position illustrated in Figure 16 to trap the inserted conductor and thereby secure electrical continuity with the contact 222 (via contact strip 220) and hence a respective data contact 36 of the plug when in position. Again it will be observed that all of the power and data handling terminals/contacts are circumscribed by a circle centred on the centre of the base plate 122 and passing centrally through the apertures 126.

The plug designs thus far illustrated are all of the rewirable type. A number of so-called non-rewirable plug designs will now be described in which the data conductors are intended to be connected to the data terminals on a one-off basis with the 10 intention that, once wired, the plug will not subsequently rewired by an end user. The nonrewirable embodiments described below are all generally similar to the embodiment of Figures I to 5 and like reference numerals are therefore used to depict like components. In the non-rewirable embodiments, the cover 12 (see Figure 1) may be designed so that it is not removable, or at least not easily removable, once fitted.

Referring now to Figure 19, the strain relief projection 34 again embodies the data terminals and contacts. The projection 34 after insertion through an aperture in the plug base 10, is held in place on the plug base 10 by resiliently deflectable clips 23 0 which may be integrally moulded with the base. It will be appreciated that the corresponding projections in the previously described plug embodiments may be likewise located on the plug base by resiliently deflectable, integrally moulded clips in similar fashion. The projection 34 comprises two terminal/contact sections 232 of electrically conductive material which are electrically isolated from one another by a central section 234 in the form for example of a moulding of a suitable plastics material. The sections 232 may be produced as brass extrusions and are coupled to the central section 234 by interengaging formations such a complementary male and female dovetail features 23 6, 23 8 which may be engaged as an interference fit to prevent separation of the sections.

The contact portions of the sections 232 are in the form of recesses 240 for receiving the bared ends of the data conductors 242. The recesses may be dimensioned for reception of a range of conductor core sizes and are oriented with their axes extending substantially parallel to the axis of elongation of the plug base. Once the bared ends of the data conductors have been inserted into the recesses, the outer walls 244 may be deformed by a suitable tool to crimp the conductor core and thereby provide a suitable non-rewirable electrical termination. For the purpose, the sections 232 will be made from a sufficiently malleable grade of brass to provide good crimping qualities. It will be observed that the data pin design in Figure 19 affords ready access to the screw heads 28 associated with the live and neutral terminal blocks 22L, 22N.

Figure 20 illustrates a similar embodiment to that of Figure 19 in which the conductors are soldered to the data pin instead of being connected by crimping. Like parts in Figures 19 and 20 are accordingly depicted by the same reference numerals. The only significant difference is that the upper ends of the sections 232 are not formed with recesses as in Figure 19; instead the conductor cores are soldered to the uppermost flat faces 250 of the sections 232.

In the embodiment of Figure 2 1, the connections between the conductors 242 and the data terminals 252 are made outboard of the axes of screw heads 28. In this embodiment, at their lower ends the conductive strips forming the data contacts 254 are similar in design to those of the embodiments of Figures I to 8. At their upper ends, i.e.

within the plug housing, each conductive strip is bent laterally to form a generally U shaped data terminal 252, the bight of which is located outboard of the screw head 28 located rearwardly thereof In wiring the data conductors, the bared ends are inserted into the U-shaped terminals 252 at the location of the bight and the upper limb of the U is then deflected, e.g. as by crimping, to trap the conductor at the outboard location to provide an effective electrical termination while allowing access to the screw heads.

Figure 22 illustrates a modification of the embodiment of Figures 1 to 5 in which the data terminals 260 are in the form of blades, i.e. spade contacts, located one behind the other in the region between the screw heads 28 (not shown). The spade contacts 260 are inclined in a direction towards the power handling terminals. Each spade contact 260 is connected to a respective data contact 36 via conductive tracks 262 on the circuit board 40 which are soldered to the u pper ends of the contacts 36 at locations where the latter project through the circuit board. The data conductors (not shown) terminate in spade terminals 266 which, in use, are engaged with the spade contacts by crimping.

Figures 23 and 24 illustrate a further embodiment of the plug component in which the strain relief projection 34 is similar to that of Figure 19 for example and embodies data handling terminals and contacts. In this case, the data handling terminals are in the form of terminal blocks 280 fitted with clamping screws 282 for securing the data conductors within bores 284 of the blocks. Data handling contact sections 286 in the forms of pins extend from the blocks 280 and are electrically isolated from one another by a central insulating divider section 288 which may be moulded into the plug base 10. The sections 286 are intearally formed with the blocks 280 and the blocks 280/sections 286 are produced from a suitable conductive material such as brass. Support ribs 290 moulded with the plug base 10 serve to locate the blocks and are provided with lead-in faces 292 to facilitate installation. If desired, clip means (e.g. associated with the support ribs 290) may be provided to hold the blocks 280 and hence the contact sections 286 in place. Ribs (not shown) may be associated with the cover 12 for co-operation with the blocks 280 and/or clamping screws 282 in order to locate the blocks/contact sections 280, 286 and prevent inward movement thereof Figure 25 illustrates a modification ofthe terminal block/contact sections 280, 286 shown in Figures 23 and 24 in which the tenninal blocks 280A are in the form of Pads to the upper faces of which the data conductors can be soldered but may be located and held within the plug base in similar manner to that illustrated in Figure 23. In the embodiment of Figures 23 and 24 (or Figure 23 when modified by Figure 25), the data handling terminals/contacts 280, 286 will be installed after the power handling terminal blocks 22L, 22N have been wired. The data handling terminals/contacts 280, 286 may be wired before or after insertion into the plug base 10. In the modification of Figure 25, the terminal blocks may be of reduced height comprared with those in Figure 24 such that access to the power handling terminals by means of a tool is possible with the terminal blocks in situ.

Figures 26 and 27 illustrate a modification of the embodiment illustrated in Figures 17 and 18 in which the data terminals of the socket are located in a central well 212 which extends from a point adjacent the well 140 for the earth terminal and between the wells accommodating the live and neutral terminal blocks 156L, N. The data terminals are mounted on an insert 300 having a plastics moulded main body 302 having a central wall 3 04 with pairs of lateral proj ections, 3 06, 3 08 and 3 10. On each side of the central wall 304, an electrically conductive strip 312, e.g. of phosphor bronze, is provided and each strip is assembled to the insert 300 and is configured as shown with springy leg terminal and contact portions 3 14, 3 16 at opposite ends of the strip.

The terminal portions 3 14 underly apertures 3 18, 3 20 and their free ends bear resiliently against intermediate sections 322 so that a bared end of a data conductor inserted into apertures 320 can be trapped between the free ends of the portions 314 and the adjacent intermediate section 322 to provide electrical continuity. Portions 314 are upwardly biased into contact with the lateral projections 306, 308 and away from the main body 302 but can be displaced downwardly by insertion of an appropriate tool through the apertures 318 thereby creating gaps between the free ends of the portions 314 and the intermediate portions 322 to allow insertion of the bared ends of the data conductors so that, when the portions 314 are allowed to spring back on withdrawal of the tool, the conductors become trapped. A cover plate 340 fits over the assembly of wells and terminals and has apertures 342 which afford access to the power conductor-receiving bores of the live, neutral and earth power handling terminals of the socket and apertures 344, 345 which register with the apertures 320 for insertion of the data conductors. The cover plate is provided with a cable restraint 346.

Each contact portion 316 slopes downwardly towards its free end, the arrrangement being such that the data contact assembly 34 associated with the plug enters at a location 317 and, as the plug slides relative to the socket to register the power-handling contacts of the plug and socket together, the data contacts of the plug ride along the respective ramps formed by the springy portions 316 which flex about the lateral projections 3 10. On completion of plug insertion, the data contacts of the plug may register with the free ends 319 of the contact portions 316. This ramp action serves to ensure good electrical contact between the data handling contacts of the plug and socket and also biases is the strain relief contact 34 towards the base plate of the socket so that the cross-piece of the "r' bears against the inner surface of the base plate of the socket. During subsequent removal of the plug, the portions 316 are restored to the position shown in Figure 27.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features disclosed herein and/or shown in the drawings whether or not particular emphasis has been placed on such feature or features.

It will also be appreciated that certain features of the invention which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.

Claims

1. An electrical connector system as defined in which each part is provided with a set of data handling terminals with which data handling conductors can be engaged, the data handling terminals having respective data handling contacts and being so arranged that, on coupling the male and female parts together, the data handling contacts of one set register with those of the other set.

2. A connector system as claimed in Claim 1, suitable for use with a B.E. S.A.

box.

3. A connector system as claimed in Claim 1 or 2 in which the power handling terminals all lie substantially wholly. within a zone circumscribed by an imaginary circle having a diameter no greater than about 60 mm.

4. A connector system as claimed in Claim 1 or 2 in which the power handling terminals all lie substantially wholly within a zone circumscribed by an imaginary circle having a diameter no greater than about 53 mm.

5. A connector system as claimed in Claim 3 or 4 in which the data handling terminals of at least one of the connector parts lie within said imaginary circle.

6. A connector system as claimed in any one of the preceding claims in which the arrangement is such that the two sets of data handling contacts register with each other on insertion of the power handling contacts of the male part through the entry apertures of the female part.

7. A connector system as claimed in any one of the preceding claims in which the arrangement is such that the two sets of data handling contacts only register after the two parts have been adjusted in the transverse direction to mechanically and electrically engage their respective power handling contacts.

8. A connector system as claimed in any one of the preceding claims in which the power handling terminals of at least of the male and female parts are of the screw clamp type.

9. A connector system as claimed in Claim 8 in which the screw-clamp type portions of the power handling terminals each comprise a block formed with a bore for reception of an electrical power conductor and the associated screw is adjustable inwardly and outwardly of the bore in a direction transverse to the bore so as to clamp an inserted conductor within the bore.

10. A connector system as claimed in any one of the preceding claims in which the data handling tenninals/contacts are so arranged that they do not impede access to the power handling terminals.

11. A connector system as claimed in any one of the preceding claims in which the male part is of elongate shape having a minor axis and a major axis, the power handling terminals of the male part are arranged with the live and neutral terminals spaced laterally relative to the major axis.

12. A connector system as claimed in Claim 11 when dependent on Claim 9 or in which the clamping screws are arranged for adjustment in a direction substantially parallel with the ma or axis and their tool-engageable heads are both presented towards one j end of the male part so that both screws can be accessed from the same side in order to facilitate wiring of the male part.

13. A connector system as claimed in any one of Claims 9, 10 or 12 in which the data handling terminals associated with the male part comprise projecting blades which are located in a zone lying between the heads of the clamping screws and one end of the male part, the blades being positioned and oriented so as to be clear of the approach path of a screw-driving tool as the latter is brought into engagement with each of the screw heads associated with the live and neutral terminals.

14. A connector system as claimed in Claim 13 in which the blades are provided with V-shaped entries for reception of conductors.

15. A connector system as claimed in Claim 13 or 14 in which the blades are arranged with their major faces extending substantially parallel to the direction of screw travel.

16. A connector system as claimed in Claim 15 in which the blades are offset from each other in such direction and/or perpendicular to such direction.

17. A connector system as claimed in Claim 15 in which the blades are arranged one behind the other in the direction of screw travel.

18. A connector system as claimed in any one of the preceding claims in which the data handling terminals of at least one of the male and female parts are located outboard of the power handling terminals.

19. A connector system as claimed in any one of Claims I to 12 and 18 in which at least one of the data handling terminals/contacts is arranged for movement between a normal position of use and a position allowing access to the power handling terminals.

20. A connector as claimed in any one of Claims I to 12 and 18 in which the data handling terminals of the male part are located at a different level relative to the power handling terminals so that access to the power handling terminals can be obtained by passage of a tool over or beneath the data handling terminals.

21. A connector system as claimed in any one of Claims I to 12 in which the data terminals of the male part are located outboard of the power handling terminals in an in line arrangement, the axis of which passes between power handling terminals of the male part so that tool access to the latter can be obtained at either side of the in-line arrangement.

22. A connector system as claimed in any one of the preceding claims in which the data handling terminals of the male part are coupled to their counterparts of the female part through a strain relief projection which holds the male part captive to the female part when the two parts have been assembled with electrical continuity between their respective sets of power handling terminals.

23. A connector system as claimed in Claim 22 in which the strain relief projection is formed at least in part by the data handling contacts.

24. A connector system as claimed in Claim 22 or 23 in which the strain relief projection comprises an outwardly projecting portion which is generally T- shaped in cross section.

25. A connector system as claimed in Claim 22, 23 or 24 in which the strain relief projection comprises a pair of conductive sections separated by a central insulating section.

26. A connector system as claimed in Claim 25 in which the central insulating 5 section is moulded integrally with a base of the male part.

27. A connector system as claimed in Claim 25 or 26 in which the conductive sections comprise extrusions of conductive material.

28. A connector system as claimed in any one of Claims 22 to 27 in which the strain relief projection is located in fixed position relative to the base of the male part by clip means.

29. A connector system as claimed in Claim 26 in which the conductive sections are removably located in the base of the male part and are held in fixed relation thereto by ribs provided on the base and/or a cover of the male part.

30. A connector system as claimed in any one of the preceding claims in which the data handling terminals of the female part are located in a central zone located inboard of the power handling terminals.

31. A connector system as claimed in Claim 30 in which the data handling contacts of the female part are located outboard of the live and neutral terminals and electrically connected to the inboard data handling terminals.

32. A connector system as claimed in any one of the preceding claims in which the live and neutral power handling terminals of the female part are located in laterally extending housing sections while the corresponding power handling contacts are located in a central housing section.

33. A connector system as claimed in Claim 32 in which the data terminals and their associated contacts are located in the central housing section.

34. A connector system as claimed in any one of the preceding claims in which the data handling terminals and contacts of the female part are carried on an insert which is fitted to the female part.

35. A connector system as claimed in Claim 34 in which each pair of data handling contacts and terminals of the female part is formed by a single strip of conductive material.

is

36. A connector system as claimed in Claim 34 in which the data handling terminals of the female part comprise cantilevered elements co-operating with respective fixed contacts so that data conductors can be inserted between the free end of each cantilevered element and the associated fixed contact.

37. A connector system as claimed in any one of the preceding claims in which the data contacts of the female part are caused to flex on coupling of the male and female parts together and provide a biasing force to hold the parts together.

38. A connector system as claimed in Claim 36 when dependent on any one of Claims 22 to 28 in which the biasing force is exerted on the strain relief projection.

39. A connector system as claimed in any one of Claims 22 to 28 and 37 in which the strain relief projection is T-shaped and in which the cross-piece of the T is arranged to bear against an inner surface of the female part when the parts are coupled together.

40. A connector system as claimed in any one of the preceding claims in which entries for insertion of the data conductors for at least one of the male and female parts are located inboard of entries for insertion of the associated power handling conductors.

41. A connector system as claimed in any one of the preceding claims, each part 10 having only three power handling terminals and only two data handling terminals.

42. A connector system substantially as hereinbefore described with reference to, and as shown in, any one of the embodiments illustrated in the accompanying drawings.

43. A connector system as claimed in any one of the preceding claims when used to transmit digital data via the data handling contacts thereof.

44. The male part of a connector system as claimed in any one of Claims I to 43.

45. The female part of a connector system as claimed in any one of Claims I to 43.