Electrical outlet sockets

Abstract

 An electrical outlet socket having a housing accommodating electrical supply terminals and related electrical power handling contacts, entry apertures through which registration can be effected between the power handling contacts of the socket and those of a plug member intended for use with the socket, and a module for enhancing or supplementing the functionality of the socket and/or plug member, the module being adapted for mounting externally of the housing.

Description

[0001] This invention relates to an electrical outlet socket which form part of an electrical connector system particularly for use in mains electricity supplies in industrial, office and domestic applications, e.g. fluorescent lighting.

[0002] The type of electrical connector system to which the present invention may typically be applied is disclosed in our prior European Patent No. 0125861, the entire disclosure of which is incorporated herein by this reference.

[0003] The system of EP-B-0125861 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:

an outlet socket member having electrical supply terminals with related electrical power handling contacts and entry apertures which are offset from the contacts; and

a plug member having projecting electrical power handling contacts for insertion through the entry apertures of the socket outlet and into offset relation with the contacts of the socket;

the two members 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 plug member mechanically and electrically with the contacts of the socket.

[0004] The present invention seeks to provide an electrical outlet socket, e.g. for use as part of a connector system as defined, with enhanced or added functionality.

[0005] According to the present invention there is provided an electrical outlet socket having a housing accommodating electrical supply terminals and related electrical power handling contacts, entry apertures through which registration can be effected between the power handling contacts of the socket and those of a plug member intended for use with the socket, and a module for enhancing or supplementing the functionality of the socket and/or plug member, the module being adapted for mounting externally of the housing.

[0006] The plug member with which the socket is used may be a power handling plug for use in conducting electrical power to an electrical power-utilising appliance to which it can be connected via a power handling cable. Alternatively the plug member may be a device which has functionality additional to or instead of power supply for distribution to a separate appliance. For instance, the plug member may itself be an electrical power utilising device and may receive from and/or supply data signals to the socket. Various forms of plug member are disclosed by way of example hereinafter.

[0007] The arrangement may be such that the socket may be used with or without the module. In particular, the module may be readily retrofittable to the socket as when enhanced or added functionality is required. Thus, a user may initially install the socket without the module and subsequently fit a module to the socket when enhanced or added functionality is desired.

[0008] The module may be removably fitted to the socket in such a way that it can be removed or replaced without disassembling the housing and/or exposing the power handling terminals and contacts.

[0009] The module may be fitted to the socket, e.g. to the housing, as a snap fit.

[0010] The housing may be provided with a cover. For example, the cover may be provided with apertures through which access to the power handling terminals may be had when wiring electrical conductors to the same.

[0011] In such an arrangement, the module may be arranged so that it can be removed or replaced without removing the cover of the housing. For instance, the module may overlie at least part of the cover.

[0012] The module may be removably interfitted with the housing on the rear side of the socket.

[0013] Another option is for the module to be assembled to the socket and then permanently secured in place, e.g. by means of ultrasonic welding. For instance, the module may be permanently secured to the cover of the housing.

[0014] The housing may for example be of elongated configuration with a least one power-handling terminal at or adjacent each end and with a reduced depth section, the module being arranged to fit into the reduced depth section of the housing.

[0015] The reduced depth section may accommodate at least one power-handling contact associated with a related power-supply terminal.

[0016] The housing may also include a channel extending lengthwise thereof and arranged for reception of part of the module.

[0017] That part of the module may accommodate functional components of the module, e.g. so that such components are located in-board of the housing.

[0018] Said module part may extend through an opening in the cover and into the channel.

[0019] The socket may be adapted to be fitted with more than one such module and the modules may have differing functionalities.

[0020] Where the socket is adapted to be fitted with more than module, the modules may be arranged to fit within a reduced depth section or sections of the housing.

[0021] In the following disclosure where reference is made to module in the singular, it is to be understood that, unless the context dictates otherwise, the statement made applies to the case where there is more than one module.

[0022] 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.

[0023] Active components, e.g. terminations, of the module may likewise lie within the imaginary circle referred to above.

[0024] The housing may be combined with a base plate for mounting the housing.

[0025] The module may be arranged to co-operate with means associated with a plug intended for insertion into the socket so that the plug participates in the enhanced or added functionality imparted by the module. Such means may comprise one or more projections (e.g. other than power-handling contacts of the plug) arranged to enter the socket when the plug is assembled to the socket and engage with a component or components of the module which is/are active in terms of functionality.

[0026] The module may interfit with the housing in such a way that an outer surface of the module is substantially flush with an outer surface of the housing. Such outer surfaces may be substantially normal to the direction of insertion of a plug into the socket.

[0027] The depth of the module may be substantially the same as the full depth of the housing.

[0028] In one embodiment of the invention, the housing defines a number of wells each accommodating an electrical terminal and/or contact of the socket and the module is arranged to extend transversely across the width of the housing, e.g. the reduced depth section of the housing.

[0029] The module may straddle the housing in such a way that a part or parts of the module extend laterally of the housing.

[0030] The lateral extension(s) of the module may accommodate a component or components associated with the functionality of the module. For instance, such component(s) may comprise termination means for electrical conductors, co-axial cables or optical fibres.

[0031] The module may provide functionality in the form of a data transmission link between the plug and the socket.

[0032] The module may be provided with one or more terminations for a data transmission conductor or conductors. The conductor(s) may be electrical conductor(s) or other forms of data transmission line such as optical fibre(s).

[0033] The data handling termination(s)/contact(s) may be so arranged that they do not impede access to the power handling terminals for the purpose of wiring electrical conductors.

[0034] The data handling termination(s) may be located outboard of the housing.

[0035] The data handling contact(s) may be located inboard of the housing.

[0036] The module may include one or more data transmission pathways extending between the termination(s) and contact(s) for interface with the plug.

[0037] The pathway(s) may extend from the termination(s) and through the housing.

[0038] The pathway(s) may be electrically conductive but may alternatively involve other forms of data transmission, e.g. transmission by way of optical fibre.

[0039] The functionality of the module is not limited to data transmission. The module may for instance serve to detect predetermined conditions such as disconnection of the plug from the socket. The module may include or be associated with a signal generator. The signal generator may for instance serve to produce a visual, audible or other human-discernible output, e.g. for use as a warning or alarm signal.

[0040] In one application, the functionality provided by the module may be for data handling 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.

[0041] Data handling terminals of the plug member may be coupled to their counterparts of the female part through a strain relief projection which holds the plug member captive to the socket when the two parts have been assembled with electrical continuity between their respective sets of power handling terminals.

[0042] The strain relief projection may be formed by the data handling contacts and may comprise an outwardly projecting portion which is generally T-shaped in cross-section.

[0043] 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 the invention with the socket, plug and functionality-enhancing module shown in assembled;

Figure 2 is a perspective view similar to that of Figure 1 but in exploded form with the main components shown separated from one another;

Figure 3 is a perspective view similar to that of Figure 2 but seen from the opposite side of the system;

Figure 4 is a similar view to that of Figure 2 but illustrating clip-in or snap-fit features for securing the module to the socket; and

Figure 5 is a perspective view of an electrical connector system in accordance with the invention in which the plug is in the form of a power-utilising device such as a motion detector or other sensor which is also linked to the module.

[0044] The system of the present invention may be generally similar to those described in European Patent No. 0125861 in which the electrical contact between the male and female components (plug and socket) is effected in a two stage sequence involving initially inserting the plug into the socket 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 plug with those of the 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.

[0045] Referring to the drawings, the system comprises a plug 10 and outlet socket 12 for use for example with a mains supply voltage of the order of 240 volts. The plug comprises projecting power-handling contacts 14, namely live and neutral contacts 14L and 14N and an earth contact 14E, for registry with respective entry apertures 16L, N and E of the socket 12, the arrangement being such that once the contacts 14L, N and E have been inserted, the plug 10 can be displaced transversely of the direction of insertion to engage its contacts with power-handling contacts 18 of the socket, namely live, neutral and earth contacts 18L, N and E, which in turn are electrically connected to power-supply terminals 20L, N and E.

[0046] The power-handling contacts and terminals 18, 20 of the socket are accommodated within a housing 22 of elongated configuration which is itself incorporated into a circular base 24 of the socket. The base 24 is formed with an annular rim 26 and apertures 28 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 24 is formed with bosses 30 lying within the circumference of the rim 26.

[0047] The housing 22 and the contacts/terminals 18, 20 it accommodates are also located within the confines of the rim 26 so that the contacts/terminals 18, 20 are located within an imaginary circumscribing circle as previously mentioned. The contacts 18L, N are located are one end of the housing 22 and the contact 18E and its associated terminal 20E are located at the opposite end, the terminals 18L, N being provided intermediate the ends in a reduced depth section 32 of the housing 22 which extends transversely of the housing 22.

[0048] The housing 22 comprises wells 34 which receive the power-supply terminals 20L, N and E, wells 36 receiving the contacts 18L, N and well 38 receiving contact 18E. The base 24 and that part of the housing 22 forming the wells 34, 36 and 38 may be formed as one-piece plastics moulding. The housing 22 further includes a cover 40 which overlies the wells 34, 36, 38 and is provided with access openings 42 for insertion of power conductors (not shown) so that the conductors can be electrically coupled to the terminals 20L, N and E. The cover 40 is profiled to afford the reduced depth section of the housing. The cover 40 may also be produced as a plastics moulding. Between the wells 34 and 36 the housing includes a channel 46 extending in the lengthwise direction.

[0049] The terminals 20L, N and E in the illustrated embodiment are of the screw clamp type in which the respective conductor is inserted into a bore in the terminal block and a screw is tightened to secure the conductor. The heads of the screws are accessible by means of a screwdriver through apertures 44 at the ends of the housing 22. Terminals other than the screw-clamp type may be used if desired, e.g. IDC terminals (insulation displacement connection), cage clamp terminals (push-in type) or solder pads.

[0050] In accordance with the invention, the socket 12 is provided with a module affording enhanced or added functionality for the socket and/or the plug 10. In the illustrated embodiment, the module comprises a low voltage data-signal handling terminal/contact set embodied in a unit which removably interfits with the housing 22. As illustrated, the module comprises a holder 48 which is generally T-shaped having a cross-piece 50 and a stem 52. The module may be a plastics moulding. The cross-piece 50 and stem 52 are each generally U-shaped in cross-section with sides walls 54, 56 and top walls 58, 60.

[0051] The side walls 54, 56 are of a height which is substantially the same as the full depth of the housing side walls. The side walls 54 of the cross-piece 50 are cut away at locations 62 and the stem 52 is dimensioned so that the module 48 can be assembled to the housing 22 in the manner seen in Figure 1 with the lower edges of the walls 54 seating on or proximate to the inner face of the base 24, the stem 52 extending through an opening in the cover 40 and being received in the channel 46. The cross-piece 50 is received in the recess formed by the central reduced depth section 32 and straddles the wells 36 so that the ends of the cross-piece extend laterally of the housing 22. When the module is fitted to the housing as shown in Figure 1, the upper walls 58, 60 of the cross-piece 50 and the stem 52 are substantially co-planar with the wall portions 71 of the cover 40. The arrangement may be such that the module 48 is releasably held in engagement with housing 22, e.g by way of snap-engaging features (not shown in Figures 1 to 3, but see Figure 4) associated with the module 48 and the housing 22.

[0052] The module in this embodiment is provided with two data terminals 60 which fit into opposite ends of the cross-piece 50 and are arranged to be wired or otherwise coupled to data conductors. For example, as illustrated each terminal 60 may comprises an electrically conductive block formed with a bore 63 and provided with clamping screw 64 to allow an electrical data conductor to be inserted and clamped, the clamping screws being accessible by a screw-driver or the like through openings 69 at the ends of the cross-piece 50. Openings 73 in the top wall 58 of the cross-piece 50 are aligned with the bores 63 to allow insertion of the electrical conductors.

[0053] The module 48 is also provided with data contacts 66 for co-operation with corresponding data contacts of the plug. The contacts 66 comprise conductive metal strips which are electrically isolated from each other and are connected to respect ones of the terminals 60, each strip comprising a first section 68 arranged to extend along the cross-piece to the central region thereof and a second section 70 which extends along the stem 52. The two sections 70 are in parallel relation to one another and are cranked downwardly to form at their ends springy contact portions 74 in registry with an opening 76 (see Figure 3) at one end of the channel 46. This opening receives a data pin 78 associated with the plug 10, the data pin having two contacts 80 which are electrically isolated from each other and engage with respective ones of the contact portions 74 when the plug is fully assembled to the socket thereby providing continuity for data transmission between the socket and the plug.

[0054] The data pin 78 serves to couple data handling terminals of the plug to their counterparts of the socket and conveniently takes the form of a strain relief projection which holds the plug captive to the socket when the two parts have been assembled with electrical continuity between their respective sets of power handling terminals. To afford strain relief projection, the pin 78 is T-shaped so that, when the plug is properly inserted in the socket and displaced transversely, the cross-piece of the T engages with the socket and is trapped until displaced in the opposite direction.

[0055] Although the module 48 is illustrated with screw clamp-type terminals, it will be appreciated that other forms of termination may be used, including co-axial cable terminals and fibre optic terminations, with appropriate modification of the arrangement for coupling of these terminal points through to the plug. Accordingly it is to be understood that, where the enhanced or added functionality involves data transmission, such transmission need not be electrical but may be optical or other mode and may be through a variety of conductors, e.g. stranded core electrical conductors, solid core electrical conductors, co-axial cable or optical fibres.

[0056] Referring to Figure 4, this illustrates one means of attaching the module 48 to the socket 12, namely a number of upwardly extending resiliently deflectable fingers 82A and 82B, each having at their free end a shaped projection 84 which is intended to partially overlie the top wall 58 of the module after the latter has been pushed downwardly between the fingers 82A, B thereby causing them to deflect and then spring back once the top wall has cleared the projection 84. Further support and location for the module 48 may be provided by additional fingers 86 which need not be provided with snap-engaging projections. The arrangement is such that the module 48 can be readily detached from the socket when desired, ie. by deflecting the fingers 82A, B sufficiently to free the module for removal. It will be understood that various other forms of "clip-in" or snap-fit arrangements may be used to secure the module 48 to the socket. In some cases, the module may be permanently secured in place, e.g. by ultrasonic welding.

[0057] The invention is not limited to the enhanced or added functionality being in the form of low voltage data transmission. The functionality may take a wide variety of other forms. For example, the removable module may be in the form of a signal generator (e.g. an visual or audible alarm). Such a signal generator could be used for instance to provide an output to indicate whether something is working or not working correctly or has been disconnected. In one embodiment, the module is used to indicate when data transfer is taking place and/or is not functioning correctly. In another application, the module may be arranged so that a signal is generated (visual or audible for example) in the event of disconnection of the plug from the socket - for use with life support systems (e.g. in hospitals) or to indicate removal of a plug from the socket in an emergency lighting system.

[0058] The socket of the invention may be designed to incorporate more than one module (not necessarily the same type of functionality). As will be apparent from Figure 1, the reduced depth section 32 may be used to accommodate a second module having functionality other than data transmission.

[0059] In practice, it is envisaged that the plug and socket system of the present invention will be made available with or without the module, at the option of the end-user. The end-user may therefore elect to purchase the system with or without the module, depending upon whether or not the enhanced or added functionality is desired at the time of purchase. Moreoever, the manner of assembly of the module to the socket affords the possibility of retrofitting if the end-user initially obtains the system without the module and subsquently elects to take advantage of the enhanced functionality.

[0060] The modules may, if desired, be designed for the purpose of controlling or switching the data signals or power that passes through the associated socket or circuit and to this end the module may be adapted for remote control operation, e.g. the module may be designed to handle infra red or radio frequency signals, e.g. it may be designed as an infra red or radio frequency emitter or receiver and include switching or other control functionality for the power and/or data signals.

[0061] As mentioned previously, the plug 10 may be a device other than a plug for distributing power to power-utilising appliances. One such arrangement is shown in Figure 5 in which the plug 10 is a power-utilising device which may receive from and/or supply data signals to the socket 12. In this case, the device 10 is provided with power handling contacts 14L, N and E for co-operation with corresponding contacts of the socket and a data signal handling member 78 for co-operation with the module 48. The device 10 may for instance comprise an occupancy sensor, a motion detector, a climate control sensor, a smoke/fire detector, a gas detector, an emergency light, an alarm system sensor, an alarm/warning sounder or light, IR/RF remote control sensors, a light sensor (e.g. for controlling and/or switching on or off lighting according to the ambient lighting level), or a diagnostic/fault finding module. In practice, the device 10 and the module 48 may be supplied as a kit for use in adapting the socket to the required functionality.

[0062] 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.

Claims

1. An electrical outlet socket having a housing accommodating electrical supply terminals and related electrical power handling contacts, entry apertures through which registration can be effected between the power handling contacts of the socket and those of a plug member intended for use with the socket, and a module for enhancing or supplementing the functionality of the socket and/or plug member, the module being adapted for mounting externally of the housing.

2. A socket as claimed in Claim 1 in which the plug member is a device which has functionality additional to or instead of power supply for distribution to a separate appliance.

3. A socket as claimed in Claim 1 or 2 in which the module is removably fitted to the socket in such a way that it can be removed or replaced without disassembling the housing and/or exposing the power handling terminals and contacts.

4. A socket as claimed in any one of the preceding claims housing is provided with a cover.

5. A socket as claimed in any one of the preceding claims, the module being arranged to fit into a reduced depth section of the housing.

6. A socket as claimed in any one of the preceding claims in which the housing is arranged for reception of part of the module that accommodates functional components.

7. A socket as claimed in any one of the preceding claims in which the module is arranged to co-operate with means associated with a plug intended for insertion into the socket so that the plug participates in the enhanced or added functionality imparted by the module.

8. A socket as claimed in any one of the preceding claims in which the module is provided with one or more terminations for a data transmission conductor or conductors.

9. A socket as claimed in any one of the preceding claims in which the module includes or is associated with a signal generator.

10. A socket as claimed in any one of the preceding claims in which the module is adapted for handling infra red or radio frequency signals.

Drawing