GB2171565A - Electrical mains distribution system - Google Patents

Abstract

Distribution system comprises a skirting board unit (10) in the form of a longitudinal slotted hollow cover member and one or more connectors (30) in sliding engagement with the cover member and providing e.g. sockets to receive 3 pin mains plugs. Wipers or collectors (34) of the connector are resiliently or otherwise engaged (e.g. by the arrangement 80-84) with conductors (24) within the cover member, the positioning of these relative to the slot being such that at least the live conductor or conductors cannot be contacted by a child's or other person's fingers inserted through the slot or by a rectilinear non-bendable object inserted therethrough. <IMAGE>

Description

SPECIFICATION Electrical mains distribution system This invention relates to an electrical mains distribution system for installation in for example domestic and commercial premises.

In conventional distribution systems, the electrical outlet points are sited at fixed locations which often prove inconvenient with the consequence that appliances have to be connected to the power points via relatively long trailing cables or extension leads which are troublesome to conceal from view or are unsightly if left unconcealed.

The object of the present invention is to provide an improved distribution system which affords greater flexibility than conventional systems.

According to the present invention we provide an electrical mains distribution unit comprising an elongated cover member which is attached to or is adapted to be attached to a generally vertical surface with one face thereof presented outwardly of said generally vertical surface, a plurality of spaced apart generally parallel conductors including at least one operatively live conductor which are arranged so as to be concealed by said cover member when the latter is attached to said generally vertical surface and slot means in said one face of the cover member to afford iimited access to said conductors, said slot means extending longitudinally of the cover member and hence in generally parallel relation to the conductors, said slot means and/or said slot means and at least the live conductor or conductors being so dimensioned and/or arranged as to preclude any possibility of contact being made with the or each live conductor if a person's fingers are inserted through the slot.

To promote further understanding of the invention, reference will now be made to the accompanying drawings showing, by way of example only, various embodiments of the present invention. In the drawings: Fig. 1 is a schematic end view of a first embodiment showing an electrical connector assembled to a distribution unit in the form of a length of skirting board section; Fig. 2 is a similar view of a second embodiment; Fig. 3 is a front view of the embodiment shown in Fig. 2; and, Fig. 4 is a further end view of the skirting board section shown in Fig. 2 in which a closure strip is also illustrated.

The embodiments illustrated in the accompanying drawings are designed to be installed as a skirting board although it will be appreciated that other applications of the invention are possible; for instance, the unit may be designed for installation at higher levels than skirting board level, e.g. above the working surfaces in a kitchen or at a suitable level in for example a showroom where television sets and other items of electrical equipment are on display.

Alternatively, the unit need not be wall-mounted but may be attached to or form a structural part of an item of furniture, a workbench or such like. The invention is also applicable to units designed to be flush mounted in relation to a vertical wall or other surface.

In the present examples the unit comprises a cover member which, in the illustrated embodiment, is in the form of a hollow section which may be moulded or extruded from a suitable plastics material and.is so designed as to form a length of skirting for installation in a room or office.

In practice, the distribution system will comprise a series of units connected together end to end either directly or by connecting units as described below.

The distribution units will be produced in one or more standard sizes and may be cut to size according to requirements.

Referring firstly to Figure 1, the cover member 10 comprises a front wall 12, a back wall 14, a bullnosed top edge 16 and a flat bottom 18. The front wall 12 is formed with slot means 20 which may comprise a single continuous slot which runs for the full length of the cover member or may consist of a number of longitudinally aligned slots. For present purposes, a continuous slot 20 will be assumed. The wall 12 is also provided with a set of grooves 22 which are parallel to one another and also to the slot 20. These grooves accommodate electrical conductor strips 24 which, in turn, will be connected to for example the live, neutral and earth terminals of the mains supply. It will be seen that when the unit is fastened to the wall of a room, the conductors 24 will be concealed from view and will only be accessible via the slot 20.The spacing between the slot 20 and the conductors 24 will be such that a child cannot touch the conductors by inserting its fingers through the slot.

The unit 10 is used in conjunction with a specially designed electrical connector 30 which may function as an outlet socket as illustrated or directly as a plug. In the former case, the socket may function as a conventional switched three-pin socket to allow it to be used with conventional 13 amp three-pin plugs.

The electrical connector 30 comprises a first arm 32 which carries a set of wipers or collectors 34 whose spacing corresponds to that of the conductors 24. The arm 32 is connected to a second generally perpendicular arm 36 which is of round section and includes a lateral finger 38 for entry into a groove 40 provided on the back wail.

The second arm 36 is attached to and forms part of the main body 42 of the connector which will incorporate terminals either for cooperation with a plug (when the connector is an outlet socket) or for connection to the conductors of a cable (when the connector is a plug), such terminals being connected to the wiper set 34 via suitable mutually insulated conductors which may extend through the arms 32 and 36. The dimensions of the arms 32, 36 are such that they can be passed through the slot 20 and the spacing of the arm 36 from the wiper set 34 corresponds to the spacing between the slot 20 and the conductor set 24.In this embodiment, the wipers or collectors 34 are not retractable or spring-loaded since externally accessible means is provided for pressing the collectors 34 against the respective conductors 24 after the electrical connector 30 has been properly inserted into the unit.

In the embodiment of Figure 1, such means is mounted on the connector 30 for cooperation with the cover member 10 and comprises at least one clamping device 80 for drawing the arm 32 towards the set of conductors 34. The device 80 may comprise one or more clamping screws or bolts 82 screw-threadedly engaged in a lug or lugs 84 which may be disposed at opposite sides of the main body of the connector 30. As will be seen, the screw 82 bears against the front face of the wall 12 and consequently tightening of the screw 82 serves to clamp the collectors 34 firmly against their respective conductors 24. The clamping means may take other forms; for example manually operable quick release cam devices which may again be provided one at each side of the connector 30 for cooperation with the front face of the wall 12.

It will be seen that when the fixture 43 and the clamping devices 80 are released, the electric connectors 30 are free for sliding movement lengthwise of the unit 10 into new positions.

Conceivably the fixture 43 may perform both functions, i.e. securing the connector in place and also pressing the collectors 34 firmly against the conductors 24. For example the conductors 24 may be located on the back wall 14 and the fixture 43 may be designed so as to draw the main body of the connector 30 towards the front wall 12 and thereby press the collectors 34 against the conductors 24.

The area 86 in the lower half of the cover member 10 may be used as a trunking arrangement to carry for example microbore heating pipework, telephone cables, T.V. aerial conductors etc. If desired, the front wall portion 1 2A may be detachable to provide access to the trunking area. The connections between the conductors 24 and the main supply cables may be achieved through the intermediary of spade-type terminals which may fit onto the ends of the conductors 24. Provision may be made for the electrical interconnection of a plurality of units arranged end to end e.g. by the use of connecting sections incorporating spring loaded contacts. One type of connecting section may be provided for units arranged in a straight run and an angle type section may be provided for the corners of a room.

Figure 1 shows the connector 30 is in its operative position in which the wipers 34 each bear against a respective one of the conductors 24. To reposition the connector at another location, the clamping means 80 is released to allow the cdnnector to be turned about the axis of the arm 36. It will be seen that a rotation of 90" will take the finger 38 clear of the groove 40 and also being the arm 32 into a horizontal position in which it is in registry with the slot 20. When in this position, the connector can be removed from the distribution unit by moving it away from the front wall to bring the arm 32 through the slot 20. The connector maythen be relocated and brought back into the operative position by the reverse procedure. In this way, considerable flexibility in the positioning of the connectors is possible.The wipers 34 and/or the grooves 22 and/ or the conductors 24 will be so designed as to permit the wipers to move into and out of contact with the conductors and the arrangement is preferably such that the wiper can only contact a conductor when the arm 32 has been turned to the operative position, i.e. so that a wiper does not temporarily engage the wrong conductor during rotation of the connector about the axis of arm 36.

Although the "insert and twist" form of electrical connector described above is preferred for its flexibility (in the sense that insertion can be readily achieved at any point along the length of the cover member) it is envisaged that the connectors may be designed for insertion of the contact-carrying portions thereof at the ends of the units 10 so that they can then be slid to the desired position. This has the advantage that a narrower slot 20 may be used but at the expense of making connector insertion cumbersome. Thus, the ends of the cover members 10 may be provided with removable end caps which can be detached to allow introduction and withdrawal of the contact-carrying parts of the sliding connectors into the interior of the cover member. An end cap will be used in any event if the unit or run of units terminates partway along a wall for example.

Conceivably, the units 10 may each be provided with an enlarged opening or openings intermediate its ends to permit insertion and withdrawal of the contact-carrying portions of the connectors at those points as well as, or instead of, at the ends of the unit. Such openings may be provided with suitable detachable covers for aesthetic purposes. In this way, the connectors can be assembled to the unit at the ends or at one of the intermediate points and then, by virtue of the slot means, they can be slid to the desired position.

Preferably the arrangement of the conductors 24 will be such that the top conductor is the live (or positive), the middle conductor is the neutral (or negative) and the bottom conductor is the earth. In this event, it may be unnecessary to take any special measures to prevent the wipers (or current collectors) temporarily engaging the "wrong" conductors.

Referring now to Figures 2 to 4, these illustrate a modified embodiment in which the conductors 90 L,N,E and the collectors 92 L,N,E are arranged differently (L,N,E respectively referring to the live, neutral and earth conductors). The connector may be of the "insert and twist" form as in Figure 1 or it may be of the type which is inserted via the ends or enlarged openings of the unit 10. Parts which are common to the embodiments of Figure 1 and Figures 2 to 4 are depicted by the same reference numerals. This latter embodiment is also suitable for production as an extruded plastic section with the conductors being inserted subsequently by "threading" from the ends.

In this embodiment, and also that of Figure 1, the inherent resiliency of the plastic material on or in which the conductors are mounted or embedded may provide some degree of springiness when the collectors engage the conductors. It will be seen that the live conductor in particular is "buried" deeply in the plastics material and can only be accessed via a narrow groove 94 thereby increasing the safety of the units since the possibility of a child being able to make contact with the conductor 90L by means of its fingers or a piece of wire or such like inserted through the slot 20 is precluded or at least very much reduced.

For aesthetic purposes, a capping strip 98 (see Figure 4) is conveniently provided for insertion, eg with a snap-fit action, into those parts of the slot 20 which are not occupied by the connectors. To aid fixing of the units to a wall surface the back wall 14 of the unit may be provided with a series of countersunk apertures (not shown) positioned in horizontal registry with the slot 20 whereby fasteners can be inserted into the apertures via the slot 20 and driven home by means of a screwdriver or other tool also inserted via the slot 20.

Although the unit 10 is conveniently formed as a plastics extrusion, it may if desired be fabricated in two-part form. For example, the unit may comprise a housing fabricated from aluminium and a "plugin" plastics insert for fitment to the housing, the conductors being carried by the plug-in insert.

For some applications the contacts or collectors of the connector may be resiliently mounted or spring loaded for engagement with the conductors, e.g.

collectors 92 L, N, E may be spring loaded for more effective contact with conductors 90 of the second embodiment.

From the foregoing it will be seen that the invention provides a mains distribution system made up of a number of units which are easy to install, afford greater flexibility in location of the outlet points and thereby avoid unsightly extension leads and such like.

Claims (16)

1.An electrical mains distribution unit comprising an elongated cover member which is attached to or is adapted to be attached to a generally vertical surface with one face thereof presented outwardly of said generally vertical surface, a plurality of spaced apart generally parallel conductors including at least one operatively live conductor which are arranged so as to be concealed by said cover member when the latter is attached to said generally vertical surface the slot means in said one face of the cover member to afford limited access to said conductors, said slot means extending longitudinally of the cover member and hence in generally parallel relation to the conductors, said slot means and/or said slot means and at least the live conductor or conductors being so dimensioned and/or arranged as to preclude any possibility of contact being made with the or each live conductor if a person's fingers are inserted through the slot.

2. A unit as in Claim 1 wherein said dimensioning and/or arrangement of the slot means and/or said means and at least the live conductor are such as to preclude contact being made with the live conductor or conductors by means of a rectilinear nonbendable object inserted at an angle through the slot, irrespective of the length and cross-sectional dimensions of the object.

3. A unit as in Claim or 2 wherein at least the live conductor or conductors are located in a recess with a narrow entrance.

4. A unit as in Claim 1,2 or 3 wherein the cover member is provided with screw or other fastenerreceiving holes in a rear wall thereof or other means for facilitating its attachment to the vertical surface.

5. A unit as in any preceding claim wherein the conductors are located in a front wall of the cover member adjacent to an interior face of said wall, the slot means opening through said front wall in spaced relationship from the conductors.

6. A unit as in Claim 1,2,3 or 4 wherein the conductors are located in wall structure of the cover member extending between front and rear wall thereof and remote from the slot means.

7. A unit as in Claim 6 wherein a live and a neutral conductor are located in operatively uppermost wall structure spaced above the slot means and an earth conductor is located in operatively lower wall structure below the slot means.

8. A distribution unit substantially as hereinbefore described with reference to and as shown in Figure 1 or in Figures 2,3 and 4 of the accompanying drawings.

9. A combination of a distribution unit as in any preceding claim and an electrical connector comprising a first part for location internally of said cover member, a second part for location externally of the cover member and a third part which can link the first two parts together via said slot means, the first part being provided with contacts for engagement with respective ones of said conductors.

10. The combination as in Claim 9 wherein the connector comprises an outlet socket for cooperation with a plug of an electrical appliance in use.

11. The combination as in Claim 9 wherein the connector is adapted to form the direct connection of an electrical appliance to the conductors.

12. The combination as in Claim 9, 10 or 11 wherein the connector is slideable lengthwise of the cover member.

13. The combination as in Claim 12 including means for releasably holding the connector at a desired position along the cover member.

14. The combination as in any one of Claims 9 to 13 wherein the conductors and contacts are resiliently urged into engagement with each other, the contacts being springloaded and/orthe conductors being resiliently displaceable to a limited degree.

15. The combination as in any one of Claims 9 to 14 including externally accessible means for urging the contacts with firm engagement with the conductors.

16. The combination of a distribution unit and an electrical connector substantially as hereinbefore described with reference to and as shown in Figure 1, or in Figures 2,3 and 4 of the accompanying drawings.