BACKGROUND OF THE INVENTION For many years, electrical distribution systems have been utilised within urban and industrial societies. In such arrangements, it is often necessary to distribute electricity via switching arrangements which are located within the environment. The switching arrangements can carry large currents at lethal voltage levels and are often located in a dangerous manner such as at the curb side where they can be subject to tampering or accidents with moving objects such as cars or the like. Further, such systems have been designed without much heed of the potential lethal effects of tampering with the system.

Prior art systems have also often involved difficult access and usability conditions and have been unduly bulky, thereby requiring specialised placement in specialised cabinets. Also such systems have included unsafe access in that many accessible parts can be tampered with in a"live"manner risking the possibilities of electrocution.

SUMMARY OF THE INVENTION It is an object of the present invention to provide for an improved form of electrical distribution system.

In accordance with a first aspect of the present invention, there is provided an electrical switching system for switching between a series of low voltage, high current

carrying sector cables, the system comprising: an insulated mounting panel having a front and back surface; a series of switching units mounted on the front surface; a series of sector cable conductive interconnection blocks mounted on a back surface of the panel and interconnected through the panel with predetermined portions of the switching units ; and a series of detachable switches for mounting in the switching units for the interconnection of predetermined portions of a switching unit so as to activate switching activities of the system.

Each of the switching unit preferably can include multiple apertures for the insertion of the detachable switches. Predetermined ones of the switching units further can include a tapoff cable interconnection means for interconnecting a tap off cable to the switching unit for taking a supply current from the switching unit. The system can also include a distribution block attached to the tap off cable for distributing multiple power cables from the distribution block.

Preferably, each of the switching units contains at least two apertures for mounting detachable switches, the apertures being substantially aligned along a first axis, and the switching units further can include a tapoff cable interconnection means for interconnecting a tap off cable to the switching unit for taking a supply current from the switching unit, the tapoff cable interconnection means being formed along side the first axis, spaced apart there from.

Preferably, the sector cable conductive interconnection blocks further can comprise a sector cable interconnection unit for clamping around a sector cable for conductively interconnecting a sector cable to the conductive interconnection block.

In accordance with another aspect of the present invention, there is provided a sector cable interconnection unit having a clamp arrangement having interchangeable parts for clamping around a sector cable having a generally triangular or tear drop

shaped cross-section. The sector cable can be clamped in multiple different orientations relative to the sector cable interconnection unit with the perimeter of the sector cable being substantially surrounded by the sector cable interconnection unit in each orientation.

The sector cable interconnection unit preferably can include a series of detachable blocks shaped to abut corresponding surfaces of the clamped sector cable. The surface abutting the sector cables preferably can include a serrated cross section engaging the surface of the sector cable. The sector cable interconnection unit preferably can include a series of separate conductive blocks having predetermined surfaces including serrated cross sections for engagement with other surfaces of other conductive blocks.

The system can also include a neutral busbar for interconnecting the neutral portions of the sector cables together; and an insulating back cover for covering the sector cables. The panel can be substantially vertically mounted and the switching units can include mating insulating jackets.

In an alternative embodiment, the sector cable conductive interconnection blocks can include a busbar having an aperture at a distal end for interconnection of at least one lugged sector cable thereto.

In accordance with a further aspect of the present invention, there is provided an electrical distribution switch for switching low voltage high current cables the switch including a series of phase units for switching each phase of a separately inputted electrical phase supply, each of the phase units further including an insulated switch mounting block for switching an output between at least two inputs the insulated switch mounting block including two detachable apertures for the insertion of a detachable switching unit for switching one of the inputs to the output.

The insulated switch mounting block can be mounted on an insulated frame and each of the at least two inputs and output are preferably interconnect to predetermined portions of the insulated switch mounting block via means of bus-bars which pass through the insulated frame.

The output can be interconnected to an output portion of the insulating block and the output portion can be further interconnected by means of an elongated insulated conductive cable or rod to a distribution block for distributing electricity to a series of interconnected cables.

The at least two inputs and output are preferably in the form of sector cables having a predetermined cross-sectional profile and the interconnection of the sector cables to the unit preferably can include a detachable conductive portion which mates with the surface of the sector cable. The sector cable preferably can include substantially three sides and the detachable conductive portion mates with two of the sides.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred forms of the present invention will now be described with reference to the accompanying drawings in which: Fig. 1 illustrates a side perspective view of a first embodiment; Fig. 2 illustrates a side exploded perspective view of the first embodiment; Fig. 3 illustrates a rear side view of the first embodiment; Fig. 4, Fig. 5 and Fig. 6 illustrate side exploded perspective views of portions of the first embodiment; Fig. 7 and Fig. 8 are sectional views through portions of the preferred embodiment illustrating the interconnection of sector cables;

Fig. 9 is a side perspective view of interconnection of the first embodiment to a base plate; Fig. 10 illustrates a side perspective view of a modified embodiment; and Fig. 11 illustrates a backside perspective view of a modified embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS In the preferred embodiment, there is disclosed a compact, touch safe, electrical distribution panel which overcomes a substantial number of the disadvantages of prior art installations.

Turning initially to Fig. 1, there is illustrated the preferred embodiment 1 in an assembled form. The preferred embodiment is designed to fit within a standard injection moulded base portion which can in turn set within a concrete gravel area or the like.

Mounted on the injection moulded base is a core panel e. g. 3 formed from multiple parts and to which is attached a back cover 4. Also mounted on the core panel 3 is a series of switch unit apertures 5-10. Each of the switch units can receive a detachable switch.

The arrangement 1 is designed to provide for three phase switching with the switches 5, 6 activating a first phase, the switches 7,8 activating a second phase, and the switches 9, 10 activating a third phase. For each phase, a separate identical switching base unit 12- 14 is provided having an injection moulded cover. The switches e. g. 5,6 and base unit 12 together provide for two input, one output switching in that two input lines can be selected for forming a current carrying interconnection with the output line in addition to providing for output line tap-off capabilities.

In the arrangement of Fig. 1, the output line tap-offs are shown 20-22. The output line tap-offs are output to distribution boxes 23-25 which then provide for the possibility

of further tap-off splitting of the outputs. For example, the distribution box 23 provides a series of distribution outputs e. g. 26.

A separate neutral line interconnection is provided with the neutrals being interconnected together via clamping base units 30-32.

The arrangement 1 of Fig. 1 is illustrated in an exploded perspective in Fig. 2. The arrangement of Fig. 2 illustrates more clearly various aspects of the preferred embodiment. In particular, the switch base units 12,13 are shown in an assembled form including their injection moulded insulating covers. The cover 14 has been removed so as to illustrate the internal conductive portions which include a top conductive portion 35, a side conductive portion 36 and a bottom conductive portion 37. A base plate 39 is formed to mate with the cover 14. As discussed previously, interconnection between the conductive portions 35,36 is provided by a detachable switch unit 40. The detachable switch unit further includes a detachable handle 41 which is inserted in slot 42 and rotated so as to lock the detachable unit 40 in place. The detachable unit 40 includes two conductive arms e. g. 43 which engage corresponding surfaces of the conductive units e. g. 35,36 when inserted. The detachable switch 40 is fully described in PCT Publication No. W099/03180 entitled"A Link Switch"published 21 January 1999, the contents of which are specifically incorporated herewith.

It will be noted that each phase is able to accommodate two link switches. The conductive unit 36 is further interconnected to its corresponding output line 22.

The core panel unit can be made up of two arms 45,46 which are attached via screw bolting arrangement e. g. 48 to corresponding second arms e. g. 49,50. These are in turn attached to a panel 51 around which the switch base units 12-14 are mounted.

The panel can be actually formed from three sub panels of the same structure which are held together by a top 58 and bottom 59 slotted clamps. The neutral interconnection can

be provided by neutral bus bar 52 which can be mounted between arms 45,46. A back cover 4 is further attached to the arms 47,49 by means of spaces e. g. 55,56 and screws e. g. 57.

Turning now to Fig. 3 there is shown a back view of the preferred embodiment with the cover shown in phantom. The arrangement 1 is designed to interconnect three power cables each containing three sector cables and a neutral cable. The power cables include two input cables and one output cable. Hence, the first phase arrangement 60 interconnects three sector cables 61-63. Each of the sector cables are connected to a corresponding clamping arrangement e. g. 66,67, 68. In practice, the sector cables can be quite difficult to manage. The clamping arrangement 66 is set off from the panel 51 by means of a spacer 68. The spacer 68 allows for simpler positioning of the sector cables 61 which can be quite difficult to manage as it must avoid the clamping unit 68.

Turning now to Fig. 4, there is illustrated a first view of the clamping arrangement 66,68 and the interconnected conductive portion 35. The conductive portion 35 is formed on the front side of the panel whereas the portions 68,66 are formed on the rear side. The arrangement is interconnected through a hole in the panel by means of screw bolt 70. Preferably, the surfaces of the units 35,68, 60 are profiled to include a serrated cross section e. g. 71 so as to provide for an increased effective electrical interconnection between the surfaces.

In Fig. 5, there is shown the interconnection between clamping unit 67 located on the back of the unit 1 and the front side conductive portion 36. Again, the two are interconnected between a hole in the panel wall 51. The interconnection is again provided by a screw bolt e. g. 75 which engages a thread within unit 67. Further, the output line e. g. 22 of Fig. 2 can be interconnected by insertion in a slot drilled in the bottom surface 76 of the unit 36 and engaged by screw bolts 78,79.

The third grouping arrangement 68 of Fig. 3 can also be interconnected with a corresponding front surface bottom conductive portion 37 by means of an arrangement of Fig. 4 which eliminates the unit 68.

Returning to Fig. 3, it has been previously noted that, the sector cables e. g. 62,61 can be difficult to manipulate into position. This is especially the case where the sector cable needs to be rotated. The sector cable often has a teardrop cross section and is formed from a conductive metal which is difficult to manipulate. The preferred embodiment therefore utilises a versatile clamping arrangement with clamping units e. g.

66-68. The versatile arrangement is illustrated 80 in Fig. 6 and includes a base portion 81, a dovetail portion 82 which is inserted sideways therein 82 and a screw bolt 83.

Importantly, two profiled spacer portions 84,85 are provided which have mating surfaces which mate both with the surface 87 and the surface 88. The other side of the surface of spacing units 84,85 can again be serrated to ensure effective electrical contact.

Fig. 7 and Fig. 8 illustrate sectional views of the corresponding assembled forms of the arrangement 80 and shows that the two spaces 84,85 can be interchanged depending on the most suitable rotation of the sector cable e. g. 88,89 inserted therein.

The preferred embodiment can be substantially pre assembled for subsequent transfer to the site of use. Once on site, as illustrated in Fig. 9, the arrangement is affixed in place by means of fixing the side panel 46 to the base rim 90. The bottom surface of the panel 46 can be profiled so as to engage with slots formed within rim 90.

Other variations on the preferred embodiment are possible. For example, as illustrated in Fig. 10, where only domestic services are required to be tapped off, the modified arrangement 100 can be provided where smaller tap-off units 101, 102,103 are

provided for tapping off main supply cables. In this case, the neutral bus bar 105 can be relocated so as to provide for more convenient access.

Other arrangements are possible. For example, a large number of other interconnection systems may already exist in the market place. It may be therefore desirable to facilitate retrofitting of units utilising the principals of the preferred embodiment. For example, in Australia, a large number of two and three way lugged arrangements have already been put in place. Where it's desirable to retrofit such arrangements, it may be desirable to modify the preferred embodiment as illustrated in Fig. 11 which illustrates a modified embodiment 110 wherein the back interconnection has been modified so as to accommodate the sector cables e. g. 111 which are terminated by lugg arrangements 112 which are common in Sydney, Australia. By providing a back end bus bar e. g. 113 it is possible to rapidly retrofit the modified embodiment 110 by disconnecting the lugg terminated sector cables from any previous arrangement and reconnecting them to the arrangement of 110. Again separate bus bars 113,114 and 115 can be provided for each phase.

The foregoing discussion describes preferred forms of the present invention.

Modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the invention.