GB2298968A

GB2298968A - Electrical distribution system

Info

Publication number: GB2298968A
Application number: GB9505014A
Authority: GB
Inventors: Peter Richard Tanner; Eric Chaplin
Original assignee: CADE DESIGN AND TECHNOLOGY LIM
Current assignee: CADE DESIGN AND TECHNOLOGY LIM
Priority date: 1995-03-13
Filing date: 1995-03-13
Publication date: 1996-09-18
Anticipated expiration: 2015-03-13
Also published as: GB2298968B; GB9505014D0

Abstract

A connector unit (10) for a distribution system has a plurality of conductor bars (13, 23) housed in a length of' conduit (11) which has a locator block (14) fitting in an end of' a length of the conduit and having recesses which receive the ends of the conductor bars (13, 23) of that conduit, and a number of resilient clips (16) which are positioned to embrace each bar (13, 23) and dimensioned to accept two bars (13, 23), whereby the respective bar ends of two adjacent lengths of' conduit (11) can be held in side-by-side electrical contact with each other within a respective clip. A socket unit is also provided.

Description

ELECIJUCAL DlSIRIBUTION SYSIBM The present invention relates to an electrical distribution system of the type in which a plurality of conductors is housed in a conduit which permits the access of pins of electrical plugs at a plurality of positions along the conduit. More specifically, the invention is concerned with a connector unit for the ends of adjacent lengths of such conduit, and to socket units for receiving said electrical plugs.

A system of the type concerned is disclosed in UK Patent GB-2109181. A disadvantage of the system shown is that when the lengths of factory-assembled conduit are installed, the interconnections between adjacent lengths require the use of a discrete sub-assembly to provide and maintain electrical continuity between the respective pairs of conductor ends of the two conduits. Such sub-assemblies are expensive and involve substantial installation time. The invention aims to provide a connector unit for such distribution systems which is cheaper to manufacture, is pre-installed in each length of conduit, and which requires no special installation time.

Accordingly, the invention proposes a connector unit for a distribution system having a plurality of conductor bars housed in a length of conduit, said unit comprising a locator block which fits in an end of a length of conduit and has recesses which receive the ends of the conductor bars of that conduit, and a number of resilient clips which are positioned at least one embracing each bar and dimensioned to accept two bars, whereby the respective bar ends of two adjacent lengths of conduit can be held in side-by-side electrical contact with each other within a respective clip.

Preferably, a locator block is mounted at both ends of each length of conduit and the connection between the leading end of one conduit and the trailing end of another is made by engagement of both locator blocks at that junction. The locator blocks can be identical in each case, and engagement be effected by simply pressing the two ends of the conduits together.

The invention also proposes a socket unit for a distribution system having a plurality of conductor bars housed in a length of conduit, said unit comprising a locator block which fits in a length of conduit and has recesses which receive the conductor bars of that conduit and a number of resilient clips, which are positioned at least one embracing each bar and dimensioned to accept and embrace also the ends of contact pins of a plug unit inserted through holes in the conduit such that corresponding bars and contact pins are held in side-by-side electrical contact with each other within a respective clip.

Clearly, since the locator block can be identical for all different purposes, this is an inventive and economically advantageous technique to adopt.

In order that the invention shall be clearly understood, exemplary embodiments thereof will now be described with reference to the accompanying drawings, in which: Figure 1 shows an exploded orthogonal view of an embodiment of a connector unit at the end of a length of conduit of an electrical distribution system; Figure 2 shows a sectional elevation of the leading and trailing ends of two lengths of conduit about to be inter-engaged; Figure 3 shows the inter-engaged ends of the two lengths of conduit in Figure 2 (to a larger scale); Figure 4 shows a cross-section on line IV-IV in Figure 3, illustrating just one locator block and the busbars; Figure 5 shows a sample of a locator block suitable for use in a connector unit or a socket unit, the clips and conductor bars excluded for clarity; and Figure 6 shows an exploded orthogonal view of a socket unit on the distribution system.

Figure 1 illustrates in an exploded view the inter-engaging ends of two adjacent lengths of conduit forming part of a busbar distribution system. The trailing end 10 of one length of conduit comprises basically a top cover 11, a bottom cover 12 and four metal bus bars 13. The covers may be of metal or plastics. The ends of the busbars 13 are held in a locator block 14 which maintains them in spaced relationship. The block 14 is preferably moulded in a suitable plastics material and receives in respective slots 15 a set of spring clips 16, one for each busbar. Each spring clip 16 is metallic and in its unflexed state has a spacing between its upstanding arms which is slightly less than twice the thickness of one busbar. The spaces 17 between each pair of locator members 18 accommodate two busbar thicknesses.

The block 14 is held in position in the covers 11, 12 by a cover plate 25 with upstanding clip members 26. The members 26 pass through holes 27 in the cover 12 and embrace the ends of the blocks 14, lodging over shoulders 28.

When assembled, the top and bottom covers 11, 12 of the conduit are closed together and held secured in any conventional fashion, e.g. by the top engaging over the bottom, with spring engagement. The top 11 stops short of the end of the bottom 12, as indicated by the arrow 19, leaving the bottom tray 12 open over the distance D. In the open portion lies the locator block 14 with the busbars 13 lying in position through the clips 16 and the spaces 17. The leading end, partly illustrated by bracket 20, of an adjacent length of conduit has exactly the same construction. However, at this end the top cover 21 is longer than the bottom cover (not illustrated) by the same amount as the top and bottom covers 11, 12 at trailing end 10. A second locator block 24 lies in the extended portion of the top cover 21 and faces downwards. The locator blocks 14, 24 are identical.Block 24 is held in position in leading end 20 by a cover plate with clip members passing through holes in cover 21 similar to block 14 in trailing end 10. An alternative view of the leading and trailing ends, in sectional elevation, are shown in Figure 2 in the correct position for the two lengths of conduit to be closed together to make electrical connection.

When the two conduits are closed together, the two sets of busbars 13, 23 overlap by an amount A as shown in Figure 1. The ends of each adjacent pair of bus bars then come to lie directly side-by-side, extending in each case through the spaces 17 and the spring clips 16 of the two locator blocks 14, 24. Thus, an intimate electrical contact is made to ensure conductivity of the busbars from one length of conduit to the other. Each connecting busbar lies face-to-face along the distance A and is clamped by two spring clips 16. This is illustrated in elevational crosssection in Figure 3.

Figure 4 shows a cross-section on the line IV-IV in Figure 3. From this, it can be clearly seen how the bus bars 13, 23 are clamped together by the clips 16.

Figure 5 shows to a larger scale one locator block 14 for use according to the invention.

Figure 6 shows in a manner similar to Figure 1 an exploded view of an electrical socket unit mounted part way along a length of conduit. The top cover 11, the bottom 12 and the busbars 13 are shown as before. A single locator block 14 is also included, and the bus bars pass straight through from one side of the block to the other. In doing so, they also pass through the spring clips 16.

In order to use this as a socket suitable for receiving an electrical plug there is also a cover unit 30 which locates in an aperture 31 in the top cover 11 of the conduit.

The cover unit has four apertures 32 arranged transverse to the conduit to receive the pins of an electrical plug of special design. The apertures 32 are aligned in each case adjacent one of the busbars 13. A further aperture 34 receives a fifth pin of the electric plug which does not make contact with a busbar, but is designed for shifting the spring biased safety shield 38.

The safety shield 38 is a movable member retained beneath the cover 30 and slidable in a channel, not illustrated, against the bias of two compression springs 34.

The springs 35 locate on pegs 36 within the structure of the cover 30. The safety shield 38 includes apertures 37 corresponding to those 32 in the cover 30, but in the position of rest the springs 35 bias the shield 38 so that the apertures 37 are not aligned with apertures 32.

When an electric plug is inserted, a fifth non-conductive pin enters the aperture 34 and applies force against a ramp 39 to push the shield 38 against its springs so that the apertures 37, 32 become aligned and the four electrical connector pins on the plug can pass through to reach the busbars 13. The electrical pins slot into the metal clips 16 and are thereby held in intimate contact, one with each of the busbars 13.

This arrangement allows the provision of electrical sockets at minimum price at desired points along each length of conduit. It is very economical to use the identical moulded locator block for both the socket units and the connector units at the ends of each length of conduit.

It will be appreciated that the exact design and layout of the locator blocks is not limited to that shown in the embodiments described. In particular, it can be envisaged that while identical blocks may be used in each length of conduit at both ends, it is not essential to provide two sets of spring clips to effect the electrical connections between the bus bars. A single set at each junction may well be sufficient.

Claims

1. A connector unit for a distribution system having a plurality of conductor bars housed in a length of conduit, said unit comprising a locator block which fits in an end of a length of conduit and has recesses which receive the ends of the conductor bars of that conduit, and a number of resilient clips which are positioned at least one embracing each bar and dimensioned to accept two bars, whereby the respective bar ends of two adjacent lengths of conduit can be held in side-by-side electrical contact with each other within a respective clip.

2. A connector unit as claimed in claim 1 wherein said locator block comprises a base plate having a plurality of upstanding posts and ribs which together define four recesses in the form of channels for receiving conductor bars, said posts and ribs also including abutments which locate and retain the resilient clips.

3. An electrical distribution system comprising a plurality of conduit lengths each having a base and a cover for connection in series, wherein each conduit length houses a plurality of conductor bars and at least one locator block, said block being retained at one end of the length and having recesses which receive the ends of the conductor bars of that conduit, and a number of resilient clips which are positioned at least one embracing each bar and dimensioned to accept two bars, whereby the respective bar ends of two adjacent lengths of conduit can be held in side-by-side electrical contact with each other within a respective clip.

4. An electrical distribution system as claimed in claim 3 wherein each conduit length houses two locator blocks, one at each end, retained respectively on the base and the cover and facing in opposite directions.

5. An electrical distribution system as claimed in claim 4 wherein the cover extends beyond the base at one end and vice-versa at the other end, and wherein the locator blocks are retained on the extended parts of the base and the cover respectively.

6. An electrical distribution system as claimed in any of claims 3 to 5 wherein the or each locator block is retained by a fixing member with fingers which pass apertures in the base and the cover respectively.

7. An electrical distribution system as claimed in any of claims 3 to 6 wherein adjacent conduit lengths are connected by pressing together the adjacent ends thereof transversely of their lengths so that the conductor bars of each conduit length come to lie side-by-side within each clip.

8. A socket unit for a distribution system having a plurality of conductor bars housed in a length of conduit, said unit comprising a locator block which fits in a length of conduit and has recesses which receive the conductor bars of that conduit and a number of resilient clips, which are positioned at least one embracing each bar and dimensioned to accept and embrace also the ends of contact pins of a plug unit inserted through holes in the conduit such that corresponding bars and contact pins are held in side-by-side electrical contact with each other within a respective clip.