Background of the invention In electrical cabling systems for providing household, residential or industrial distribution, it is often necessary to connect one cable to another. This is often done by known piercing connectors which, through an applied force, operate to pierce an insulating outer sheath of a cable.

There are a number of desirable attributes of piercing connectors. Firstly, the piercing connectors are ideally simply manufactured utilising inexpensive materials so that their unit price is kept low. Further, due to operating environments, the piercing connector is ideally, in a worse case, able to be submersed in a liquid and still be able to operate effectively.

Unfortunately, common piercing connectors are often fully conductive and do not satisfy this requirement and often require separate heat shrunk coverings to ensure full insulating capabilities.

Further, due to a wide range of cable diameters likely to be handled in use, it is desirable that a single piercing connector can be utilised with a wide range of different cable diameters and different cable arrangements.

Summary of the invention As an object of the present invention to provide a novel form of piercing connector of inexpensive construction which also alleviates at least one of the aforementioned problems.

In accordance with a first aspect of the present invention, there is provided a piercing interconnector for interconnecting cables having conductive cores and an insulating jacket, the interconnector comprising: a non-conductive block having a series apertures defining a series of interconnected chambers within the block, at least a first and second aperture adapted for the insertion therein of one of the interconnecting cables; a conductive piercing unit having a series of piercing protrusions insertable in a third one of the apertures; engagement means for insertion into the third aperture and adapted to, when in use, urge the conductive piercing unit against the interconnecting cables so that the piercing protrusions pierce the outer insulating jacket of the cables, making conductive contact with the cores.

The conductive piercing unit preferably can include a portion having a cross sectional area dimensioned so that the conductive piercing unit acts as a fuse upon the current flowing through the piercing interconnector exceeding a predetermined limit. The interconnector preferably can include a cavity located below the portion such that, on fusing, the portion flows into the cavity, thereby fusing the portion.

The cavity can be formed in a separate insulating block located between the conductive piercing unit and the interconnecting cables. Further, a second separate insulating block can ideally be located between the conductive piercing unit and the engagement means, the second insulating block including abutting edges which, upon softening of the portion, act to slice through the conductive portion so as to fuse the conductive piercing unit.

The engagement means can be further adapted to seal the third aperture in a water tight manner. The engagement means can comprise a plate and an urging means adapted to urge the plate against the conductive piercing unit. The urging means can comprise a screw bolt which engages the walls of the third aperture so as to urge the plate against the conductive piercing unit.

The plate preferably can also include an O-ring seal around an external circumference thereof, the O-ring seal providing a seal against portions of the wall of the third aperture.

There is preferably also provided a non-conductive pliable material insertable into the third aperture before the conductive piercing unit such that upon urging of the conductive piercing unit against the cables the pliable material flows around the insulating jacket and the conductive piercing unit so as to partially insulate the conductive piercing unit against external moisture. Preferably, before the urging, the pliable material acts to hold the conductive piercing unit in a spaced apart relationship from the first and second aperture so as to allow the insertion of the interconnecting cables therein.

The first and second aperture can also include an O-ring sealing means for providing an O-ring sealing of the non-conductive block upon insertion of the interconnecting cables.

In one embodiment, the non-conductive block can be made up of a number of sub- blocks which, in use, are preferably clamped around at least one of the interconnecting cables.

The number of interconnecting cables can be varied in accordance with requirements.

The arrangement preferably also includes the utilisation of a non conductible detachable end cap for insertion over at least one of the interconnecting cables, the outer circumference of the cap having a snug fit with the first or the second aperture. The end cap preferably can include a spaced apart series of O-ring formations along a portion of the cap, the 0-rings engaging with an outer surface of the insulating jacket so as to seal and end face of the interconnecting cable from moisture.

The engagement means and the walls of the third aperture can include a mateing racheted surface for maintaining the engagement means in firm interconnection with the conductive piercing unit. In one embodiment, the engagement means is initially urged against the conductive piercing means by a detachable clamp.

In accordance with a further aspect of the present invention, there is provide a piercing cable interconnection unit including: a first substantially non conductive retaining body including at least one ratcheted surface and an internal conductive core having a series of interconnected conductive protuding portions; and a second substantially non conductive retaining body having a second ratcheted surface and a series of apertures for the insertion of distribution cables having a conductive core; wherein, in use, when the first non conductive retaining body is forced towards the the second substantially non conductive retaining body, the ratcheted surfaces mate to ratchet the first body towards the second body and the distribution cables are simultaneously pierced by the conductive protruding portions.

The unit can further include a resilient non conductive sealing unit for interposing between the first body and the second body to provide a watertight seal therebetween.

In accordance with a further aspect of the present invention, there is disclosed a cable interconnection block comprising a non-conductive block including a central cavity; a first aperture in the surface of the block and interconnected with the central cavity for the insertion of a first conductive cable having an insulated outer covering; a second aperture in the surface of the block and interconnected with the central cavity for insertion of a conductive piercing connector; a third aperture in the surface of the block and interconnected with the central cavity; a conductive piercing connector for insertion into the second aperture, the connector having: a first profiled edge which, upon insertion of the connector into the second aperture, mates with a surface of the first conductive cable and a second profiled edge which, upon insertion of the connector into the second aperture, projects out of the third aperture; a sealing means for sealing the second aperture, sealing the piercing connector in the cavity; such that, upon application of a translational force to a surface of the conductive piercing connector, the first profiled edge pierces an outer covering of the first conductive cable so as to form a conductive interconnection between the first conductive cable and the conductive piercing connector.

Preferably, the sealing means forms a water tight seal of the second aperture and the insertion of the first conductive cable into the first conductive cable into the first aperture forms a water tight seal of the first aperture. The water tight seals can be formed by means of an 0-ring sealing of the first and second aperture. The non-conductive block can be formed from injection moulded plastic.

In accordance with a further aspect of the present invention, there is provided a power connection system for interconnecting with a power supply cable with at least one power distribution cable, the power supply cable including an outer non-conductive jacket and at least one internal conductive conduit, the system comprising: a first clamping unit adapted to be clamped around the cable, the clamping unit including a series of apertures; a cable surface removal unit for insertion in the aperture and adapted to provide for the removal of portions of the non-conductive jacket adjacent the aperture; a connector unit for insertion into the aperture after removal of the portions, the connector unit providing for a conductive interconnection with the internal conductive conduit, the connector unit comprising: a non-conductive block including a central cavity; a first aperture in the surface of the block and interconnected with the central cavity for the insertion of a first conductive cable having an insulated outer covering; a second aperture in the surface of the block and interconnected with the central cavity for insertion of a conductive piercing connector; a third aperture in the surface of the block and interconnected with the central cavity; a conductive piercing connector for insertion into the second aperture, the connector having: a first profiled edge which, upon insertion of the connector into the second aperture, mates with a surface of the first conductive cable; a second profiled edge which, upon insertion of the connector into the second aperture, projects out of the third aperture; a sealing means for sealing the second aperture, sealing the piercing connector in the cavity; the clamping means further comprising adjustment means for applying a force to the surface of the sealing means which results in the first profiled edge piercing an outer covering of the first conductive cable so as to form a conductive interconnection between the first conductive cable and the conductive piercing connector, and the second profiled edge firmly abutting the surface of the internal conductive conduit.

Brief description of the drawings Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 illustrates a perspective view of a first embodiment; Fig. 2 illustrates an exploded perspective of the first embodiment; Fig. 3 and Fig. 4 illustrates sectional views through the first embodiment at various stages of operation; Fig. 5 illustrates a second embodiment; Fig. 6 illustrates an exploded perspective view of the second embodiment; Fig. 7 and 8 illustrates sectional views at various stages of operation of the second embodiments; Fig. 9 illustrates a capping mechanism for utilisation with the second embodiment; Fig. 10 illustrates an exploded perspective view of a third embodiment of the present invention; Fig. 11 illustrates an alternative form of piercing interconnect block having differing fusing characteristics; Fig. 12 illustrates an exploded perspective of a further embodiment; Fig. 13 illustrates the assembled embodiment of Fig. 12 utilising a G-clamp arrangement; Fig. 14 illustrates the final assembled form of the further embodiment; Fig. 15 is a sectional view through the line XV-XV of Fig. 14; Fig. 16 to Fig. 19 illustrates sectional views of various alternative embodiments; Fig. 20 illustrates an exploded perspective view of a further embodiment; Fig. 21 illustrates an exploded perspective view of a further embodiment; Fig. 22 illustrates an exploded perspective of a four core sector cable piercing arrangement; and Fig. 23 illustrates a sectional view through an assembled portion of the arrangement of Fig. 22.

Description of the preferred and other embodiments In a first embodiment, a simplifie inexpensive form of piercing connector is provided having an outer sheath which can be formed substantially out of a non-conductive plastic type material. A connector having a movable brass piercing element is also provided and a mastic type material which helps provide for an effective sealing of the piercing connector around a cable to be pierced so as to provide for a fully insulating arrangement which can be exposed to harsh environments whilst still being fully functional.

Turning initially to Fig. 1, there is illustrated a prospective view of the first embodiment 1. In the first embodiment, it is desired to interconnect two wires 2,3 by means of a piercing interconnect. The first embodiment 1 achieves this interconnection in a compact manner such that the resulting arrangement is substantially waterproof and can be conveniently and inexpensively constructed.

Turning to Fig. 2, there is illustrated the first embodiment 1 in an exploded perspective view. Each of the wires is inserted in an aperture eg. 5 with an O-ring 6,10 providing a seal again the walls of the inserted wire. The unit 7 is slotted into the hole 8 so as to provide a snug fit. The second wire is treated similarly utilising O-ring 10 and plug unit 9. Whilst Fig. 2. illustrates an exploded perspective, the arrangement can be conveniently packaged as shown in Fig. 1 for the insertion of wires 2 and 3 and the utilisation of an Allen key to tighten screw bolt 11.

Returning to Fig. 2, a mastic material 13 is inserted in the aperture 14 followed by a conductive piercing interconnect block 15 which eventually pierces the inserted wires. A second O-ring system comprising plate 16 and O-ring 17 which fits around the circumference of the plate 16 is inserted into the aperture 14. The screw bolt 11 is then utilised to seal the piercing connector block 15 within the body portion 4. The body portion 4 and screw bolt 11 can be constructed from many different types of tough non-metallic material such as a tough plastic material. For example, a 60% glass filled nylon material has been found to be suitable for the body. Ideally, the materials utilised have hydrophobic properties so as to reduce the opportunities for absorbing water in use. One example of alternative material that could be utilised is glass filled polypropylene.

Turning now to Fig. 3 and Fig. 4, there is illustrated sectional views through the arrangement of Fig. 1. Fig 3 illustrates a sectional view before the insertion of any wires and clamping and Fig. 4 illustrates a sectional view after clamping. Before clamping, the mastic 13 advantageously operates to keep the piercing elements of the piercing interconnect block 15 clear of the aperture 8. The piercing interconnect block 15 can be inserted and the screw 11 screwed into a mating aperture to a pre-determined extent. Subsequently, the wires between which a piercing interconnect will be formed are inserted in the apertures eg. 8,18. Upon insertion of a wire in the aperture 8,18, an Allen key is inserted in the top of screw bolt 11 and the bolt tightened. The result is as illustrated in Fig. 4 with the piercing interconnect block 15 piercing the outer insulating surface of the wires 2,3 and further piercing a portion of the conductive cores the wires themselves so as to form a conductive path between the wires 2,3.

As the mastic is compressed it also flows through the holes eg. 20 in the plate 16.

Further, the increased pressure also results in the mastic flowing around the seal between the wires eg. 2 and body 4. Further, it has been noted during tests that any air pockets formed during the compression of the mastic are likely to be substantially reduced as a result of air flowing along the small spaces between the wire strands of wire 2,3. Hence, air locks are avoided due to air escaping along the strands of the cable. The utilisation of the mastic and O- ring system normally provides for an excellent seal which helps to allow the embodiment to tolerate harsh environments such as those containing dampness or water penetration. Further, the embodiment can be manufactured in a extremely inexpensive manner and has only one conductive component being the piercing interconnecting block 15 allowing for live operations to be carried out.

Obviously, minor variations are possible. For example, where higher tension piercing operations are required, a helli-coil can be inserted in the body 4 so as to properly receive the screw bolt 11 and to allow for high tensioning capabilities. Obviously, in different arrangements, different tension limiting devices can be utilised in tightening the screw bolt 11 so as to meet particular performance requirements. It has been found in practice that a hydrophobic glass filled nylon or polypropylene is highly suitable for use in forming the both body 4 and screw bolt 11.

Turning now to Fig. 5 to Fig. 8, there will now be illustrated a second embodiment of the present invention. The second embodiment as shown in the figures can be utilised to provide for a piercing interconnect mechanism for dealing with cables having substantially different cross-sectional sizes. Further, the arrangement 25 is able to provide for an interconnection between a service cable 26 and a tap off cable 27. The arrangement of Fig. 5 is provided so as to allow for piercing access to cables in place in a highly convenient manner. In Fig. 6 there is illustrated an exploded perspective of the arrangement of Fig 5. The second embodiment includes a core unit 30 which mates with unit 31 so as to clamp around a cable by means of screw bolts 32,33. The portions 30,31 are placed around the cable and the bolts 32, 33 tightened so as to be firmly clamped around the cable. The second tap off cable is inserted through an aperture in plug 35 and O-ring 36 so as to abut an end surface inside the unit 30.

A piercing interconnection block 38 is inserted in aperture 39 and sealed by plate 40 and O-ring 41. A screw bolt 42 is then utilised to initially hold the components within the aperture 39 before insertion and to subsequently compress the piercing interconnection block 38 against the inserted wires. An example of this process is illustrated in Fig. 7 and Fig. 8 with Fig. 7 illustrating the arrangement before compression and Fig. 8 illustrating the arrangement after compression. The arrangement of Fig. 7 and Fig. 8 dispenses with the utilisation of the mastic.

However obviously, in alternative embodiments mastic could be included. As shown in Fig. 8, the screw bolt 42 is screwed by a tension wrench or the like to force the piercing interconnect block 38 to pierce the inserted wires 26,27.

Again, the arrangement of the second embodiment provides a simple and compact form of manufacture of a piercing interconnect. Obviously, many different embodiments can be created to cater for many different possible cable sizes. Alternatively, an even more economical solution may be to provide for a series of standard sized embodiments that can handle a range of wires by means of suitable capping or covering arrangements. An example of a suitable insulating cap for use with such arrangements is illustrated in Fig. 9 wherein a cable 45 is fitted with a rubberised insulating cap 46. The cap 46 has a standardised outer diameter for utilisation with a particular embodiment. The cap 46 includes a series of ridges 47 which assist in providing a water tight seal to the end of the cap 46. The cable and cap can then be left in situ until such time as they are required to be utilised. The cap 46 can be fitted 45 through the utilisation of a suitable evaporative solvent such as benzol or the like.

In order to utilize a standard sized piercing interconnector with multiple different cables, end caps having differing thickness walls but a same outer diameter can be provided for fitting over different sized cables When it is desired to interconnect the wire 45 with a second wire, the end, including cap 46 is inserted in an embodiment having suitable sized apertures and the piercing operation is carried out. The insertion can be assisted through the utilisation of appropriate evaporative solvents such as those aforementioned.

Turning now to Fig. 10, there is illustrated an exploded perspective view of a third embodiment 50. The arrangement of Fig. 10 is similar to the arrangement of Fig. 2 but for the substitution of the parts 51-53. The arrangement 50 of Fig. 10 is designed to provide for "fusing"capabilities upon a short circuit or the like. In this arrangement, a first flame retardant plastic section 51 is inserted into the aperture 14 after the mastic type compound 13. The unit 51 is formed so as to have a centralised cavity 55 for receipt of molten material upon fusing. A piercing interconnect block 52 is formed from hard brass or copper and operates in a similar manner to the unit 15 of Fig. 2. However, the block 52 includes a thin portion 56. Upon receiving an excess current, the thin portion 56 is designed to melt with the circuit being broken as a result of the molten metal flowing into cavity 55.

On top of the block 56 is included a clamping spacer 53 which is clamped against the piercing interconnect block 52 by means of screw bolt 11. The clamping spacer 53 can again be formed from fire retardant plastic. The unit 52 is designed so as to fuse upon an excessive current being drawn between the input and output cables. The fusing results in a melting of the thinned portion 56 which fuses as a result of flow of the molten material. The clamping spacer 53 also assist in fusing operations due to end portions eg. 58.

Of course, alternative embodiments are envisaged. For example, the O-ring system (16 and 17 of Fig. 2) could also be included between clamping spacer 53 and screw bolt 11.

The thinned portion 56 of piercing interconnect block 52 can be thinned to an extent so as to allow for predetermined fusing characteristics. Other arrangements of piercing interconnect block may be possible. For example, in Fig. 11, there is shown an alternative piercing interconnect block which includes an accurately thinned bridge section 61 which provides for more accurately calibrating fusing characteristics.

It can therefore be seen that the arrangement of Fig. 10 provides for a piercing connector which further has fusing capabilities. Such an arrangement can, in certain circumstances, provide for enhanced operational capabilities.

Turning now initially to Fig. 12, there is illustrated a third embodiment of the present invention. The third embodiment as illustrated in Fig. 12 is designed to interconnect four cables 71-74 together by means of a piercing interconnect. Each cable includes an end cap so as to deal with different size cables. Although Fig. 12 illustrates cables of substantially the same size, when a different size cable is provided, preferably the outer radius of the end cap 75 is substantially constant.

A pair of cables including end caps is inserted into a locater unit e. g., 77,78. The end caps being inserted in mating apertures e. g., 80,81 and 82,83. The locater units are then each inserted into a mating unit 85 which has ratchet type mating surfaces e. g., 86 which mate with corresponding surfaces 87 of the mating unit e. g., 77. The mating unit 85 includes a series of piercing elements e. g., 89,90. Between each locater unit e. g., 77 and mating unit 85 is a rubber sealing plate 91,92. The rubber sealing plate includes apertures e. g., 93,94 which surround the piercing elements e. g., 89,90. The locater unit 77 is forced down towards the piercing elements 89,90 so that the piercing elements in turn pierce the cables 71,72. The locater units can be forced into the mating unit utilising a G-clamp type arrangement 98 as illustrated in Fig. 12. The G-clamp can be temporally utilised to apply pressure so that the locater units are forced along the mating unit towards the piercing connector. The ratcheting surface holding the locater units in firm engagement with the mating unit.

Returning to Fig. 12, the portions 77,78 and 85 can be made from glass filled nylon or other strong plastic type material. Upon being assembled, an optional spring clip 99 is utilised to hold the arrangement in strict engagement. The final assembled form including the spring clip is illustrated in Fig. 14 with Fig. 15 illustrating a sectional view through the line XV-XV of Fig. 14. The arrangement of Fig. 15 again providing for an extremely compact and economical to manufacture form of piercing connector.

The arrangement of Fig. 12 to 15 can be extended to other forms of interconnection. For example, Figs. 16-19 illustrate sectional views of various alternative arrangements for providing interconnection between different numbers of cables. Fig. 16 illustrates a three way interconnection, Fig. 17 illustrates a two way connection, Fig. 18 illustrates a distribution arrangement where one large cable 104 is interconnected to a series of smaller cables 105-107.

Fig. 19 shows a further alternative arrangement.

Various combinations of the principles of the foregoing embodiments can be provided.

For example, Fig 21 illustrates an embodiment 110 which combines the principles of the arrangement of Fig. 6 and a dovetail compression to provide an interconnection to three cables.

In this arrangement, a piercing connection is provided to a cable 111 by first clamping around the cable utilising clamping portions 112,113 and screws 118,119. Tap off cables are inserted through apertures 115,116 as previously discussed into an insulated locator block 120. The located block 120 is inserted in to void 121 and piercing element 122 inserted in locator block 120 so that top surfaces mate with corresponding surfaces in the locator block. Dove tail portion 124 inserted in slot eg. 126 and the screw bolt 125 is inserted into aperture 128 and an Allen key used to tighten the bolt, thereby forcing piercing element 122 to simultaneously pierce multiple surfaces to form an interconnection. Obviously, the arrangement of Fig. 19 can be provided to pierce a cable in situ.

Other in situ arrangements are possible. For example, in Fig. 21, the racheting principle is utilised to provided for an in situ interconnection. Again, portions 131,132 are used to clamp around cable 111. The two tap off cables 135,136 including resizing caps 137,138 are inserted into an initial clamping unit 133. The clamping unit is similar to the arrangement of Fig. 12 and a G-clamp used to force blade edge 140 to pierce cable element eg. 135. Next the unit 133 is inserted into aperture 141. The dovetail piece 142 is inserted into corresponding slot e. g. 144 and screw bolt 146 used to force piercing element 147 to pierce the surface of cable 111.

The piercing arrangements of the foregoing embodiments can be further extended to even more complex arrangements. For example, where it is desired to pierce sector core cables the principal of the foregoing embodiments can be readily extended. An example of a sector core cable type piercing arrangement is that disclosed in PCT application number PCT/AU99/00477 entitled"A T-Joint Connector"filed 15 June, 1999, assigned to the present applicant the contents of which are hereby incorporated by cross reference. This application discloses a four core sector core arrangement for"taping off distribution cables from a sector cable. The aforementioned arrangement can be extended to utilising a piercing connector.

Turning to Fig. 22, there is illustrated a modified arrangement 300 which is highly similar to the arrangement of Fig. 14 of the aforementioned PCT Application but which introduces a new connector block which utilises the concepts for piercing connectors aforementioned to provide improved waterproofing and interconnection capabilities.

Fig. 22 illustrates in an exploded perspective various portions of three connector block arrangements 301,316 and 317. The arrangement 301 includes an exploded connector block, the arrangement 316 includes a partially assembled connector block having insert leads 318, 319. The connector block 301 is shown in an exploded perspective in Fig. 16 and operates as a piercing connector wherein cables are inserted through holes 302,303 and the cables have not been shown. The cable is sealed by O rings 304,305 inside a plastic injection moulded part 307. Next, a brass element 309 is inserted into the block 307 with the brass element 309 having piercing portions 310, 311 which mate with the surface of the inserted cables which have been inserted in holes 302,303. Next, an O ring 303 is inserted and a plug 314 is in turn inserted in the cavity as is best illustrated in the second connector block arrangement 316.

In the arrangement 316, the plug 314 is inserted in a corresponding cylindrical cavity with the plug 314 including an O ring placed around the edge thereof. The plug 314 is compressed into the cavity by means of screw bolt 320 and plate 321 which is inserted as shown in the arrangement 317. Upon insertion, the screw bolt 320 is tightened so as to compress the disk 314 on the back surface of the brass element 309 which causes the edges 310,311 to pierce the cables inserted in holes 302,303 and the edge 322 bites into the aluminium sector cable as is more clearly illustrated in Fig. 23 which illustrates a sectional view through an assembled portion of the arrangement of Fig. 22.

The arrangement of Fig. 22 and 23 provides the added advantages that a higher level of waterproof sealing is provided for cables inserted into the connector block. This means that in certain circumstances it may be no longer necessary to fully encase the connector block and associated clamping arrangement in a resinous material. Experiments conducted by the inventor include substituting a foam setting material for the resinous material in the cavity between the case and the connector block. The dispensing of the utilization of the connector material leads to a potential for substantial reductions in cost and also in the removal of the need to deal with resinous materials which can be highly toxic. It would be further evident to the person skilled in the art that the ratchet clamping arrangement of Fig. 21 could be extended to the arrangement of Fig. 22 and Fig. 23.

It will be further evident that other combinations or arrangements of each embodiment are possible. For example, further apertures could be provided for the insertion of further wires of varying diameters and the relevant piercing interconnecting block modified so as to pierce each of the tap off cables simultaneously. Hence many different combinations of inputs and outputs in number and size are possible.

It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.