GB2397953A

GB2397953A - Electrical cable jointing apparatus

Info

Publication number: GB2397953A
Application number: GB0302257A
Authority: GB
Inventors: John Cameron; Douglas Fury; Keith Gordon; Augusto Vanso
Original assignee: TEN47 Ltd
Current assignee: TEN47 Ltd
Priority date: 2003-01-31
Filing date: 2003-01-31
Publication date: 2004-08-04
Also published as: GB0302257D0

Abstract

The apparatus consists of a pair of electrically insulating, mutually connectable sleeve type housings 3 and 5 having through holes which allow high tension cables 2 and their associated connectors 4 to connect to an electrical connector bridging piece 21 located at least partly within each of the housings. The cable connectors may be bolted to the bridging piece. The insulating housings may include a keying means. The two parts of the housing may attached by locking ring 15 and a screw fit end seal 19 and inner sealing ring 17 may also be provided.

Description

Electrical Cable Jointing Apparatus The pró ant invention relates to

electrical cable jó:intinq ap-:ar^atus and in particular to electrical cable j;intirr:- a.:paratus for use with cable suitable for -cr-:retió>n t-ó-' commercial power generators.

When -'nreóLirlg power sources such as commercial ónó-r:atc,ó. to an electrical system, it is necessary to I() use heavy duty cable which is capable of withstanding the t-r.iglr vó:Ll.ólós and amperages of the generator. Currently ó--.hió treat i-; used for this purpose is provided on spools -arid.rbló- its cut to predetermined lengths depending upon l:ó:e r::'li:. :aLi<:::rl. Iypically, spools contain 100 metres, 50 mct.re.ió::r- 25 mctres of cable.

In cr-ctcr to Connect these cables to an electrical system, lug:ó:->nnó. ctors are typically mounted on the end of the c.-rbles. Móunting of these lug connectors involves str-i:::>ir-r<-; the insulating material from the end of the ó:al-'l.e:rd r.imping the conducting material into the open .ó-ó,l:! I!Jó.

Tl- i; ó>LI:c-r-r neóessary to connect together two or more 1-róth; -if..able in order, for example, to achieve an <'vc:radl 1CóI::h that is suitable for connecting the cr-rer:tr- t:: art electrical system. Currently there are a r-r:mlór (-it ways ire which the separate lengths of cables ó:.-n be.óre-tód toóó-ther. 3()

(Erie:---;-;ibló. way its to cut off existing cable lugs and til on óIórtri.cal plug and socket connector to each cable ó>r:ó1, ll-rer join the two cable parts together. However óló:ti::rl có:;nnectors operating at high currents and voltages are expensive and therefore in many cases the use of such connectors is not cost effective. Also, the use of cabling of this type is usually to allow temporary connection between for example, a generator and an electrical system. Therefore when the user wishes to remove the electrical connectors he has to cut off the electrical connectors and then crimp the standard lug terminals back on to the cable which have just been cut off to allow the electrical connector to be attached. In addition, use of a connector of this type significantly reduces the electrical performance of the cable.

Consequently, the use of plug and socket connectors is not flexible enough from a logistical point of view, is expensive in both the procurement of the connectors and time for assembly and retrofit and reduces the electrical performance of the cable.

Another possible connection means is provided by having an electrical connection box manufactured with bus bars to connect the cable ends together. However, the cost of such a connection box is very high as these boxes have to be specially manufactured for the purpose. Also the physical size of the box would result in significant storage and transportation costs. In addition, the cables typically contain five cables (earth, neutral and three phase live cables) which have to be physically brought to one common box to be jointed and then taken off to the supply area. Therefore, this is expensive in terms of the cost of purchasing a bespoke electrical connection box and in terms of the cost and time required for connecting the box into the electrical system.

As a consequence of these costs many users simply purchase a drum of cable containing for example, 400 metres of cable and then reel off and cut the required length from the drum. However, after the job is finished the user is left with a length of cable that is only suitable for use when the next job requires that specific length of cable to be used. However if a job requires a longer length of cable to be used, the user will be unable to use the pre-cut cable and will be forced to reel off and cut this longer length of cable from the spool.

It is an object of the present invention to provide a quick and inexpensive apparatus to allow the connection together of lengths of heavy duty cable.

In accordance with the first aspect of the invention there is provided an electrical cable jointing apparatus for connecting together electrical cables having cable connectors attached to the ends thereof, the jointing apparatus comprising electrical coupling means and electrical insulating means, the electrical insulating means having first and second mutually connectable sections, each of the first and second sections being provided with a recess shaped to accommodate at least part of the coupling means, wherein the coupling means is adapted to receive a first cable connector said cable connector being expendable through the first section of the insulating means and being adapted to receive a second cable connector expendable through the second section of the insulating means.

Preferably, the recess is provided with an abutment to restrict longitudinal movement of the electrical coupling means.

Preferably, the first and second mutually connectable sections are provided with keying means to allow the connection together of the first and second sections in a predetermined orientation.

Preferably, the keying means comprises at least two holes contained on opposing faces of first and second sections, the holes being adapted to receive pins, on the second and first sections respectively.

Preferably, at least one of the recesses on the first and second sections is shaped to receive a cable connector in a predetermined orientation.

Preferably, the first and second recesses are each shaped to receive a connector such that the electrical cables attached thereto are arranged substantially coaxial with respect to one another.

Preferably, the end of each of said first and second sections of the electrical insulating means remote from the opposing surfaces is provided with a removable seal.

More preferably, the removable seal provided in each of the first and second sections is an outer screw ring and an inner sealing ring.

Preferably, a locking mechanism is provided on the first and second sections.

Optionally, the locking mechanism comprises a locking ring and thread provided on the first and second sections I respectively such that the locking ring is connectable to the screw thread.

Optionally, the locking mechanism comprises a bayonet or push pull connector.

Preferably, the locking mechanism is further provided with a padlock.

Preferably, the electrical coupling means comprises a block having fastening means for fastening first and second connectors thereto.

Preferably, the fastening means is provided by a bolt connectable through a plate in the fastening means and at least one other plate removably secured between the sides of the block.

Preferably, the electrical coupling means is provided with positioning means to ensure the correct positioning of the bolt in the fastening means.

Preferably the positioning means are screws.

Preferably the jointing apparatus is designed for use with heavy duty power cables.

More preferably the power cables are suitable for use with currents of over Scamps. More preferably the power cables are suitable for use with currents over 100amps.

More preferably the power cables are suitable for use with currents of less than 1000amps.

The present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a sectional view of a cable jointing apparatus in accordance with the present invention, the apparatus containing a pair of cable ends; Figure 2a is an end view of a first section of the jointing apparatus showing the recess and figure 2b is a side view of the first section with the locking ring cut away; Figures 3a and 3b are end views of the first section and second section of the jointing apparatus positioned to show the orientation in which they are connected together; Figure 4 is an exploded view of the electrical coupling means and also shows two cable ends positioned to be attached thereto; Figure 5 is a second exploded view of the electrical coupling means in which positioning screws are shown; Figure 6 is a cross sectional view of part of the jointing apparatus in which a padlock is shown on the sealing ring; and Figure 7 is a sectional view of a further embodiment of the present invention containing an insulating extender piece.

Figure 1 is a sectional view of an embodiment of the electrical cable jointing apparatus. The jointing apparatus 1 is constructed from a first section or sleeve 3 and second section or sleeve 5. The sleeves are constructed from a mechanically robust material with excellent electrical insulating properties. The interface at which opposing end faces of the sleeves 3 and 5 meet is indicated by reference numeral 6. Both sleeves 3 and are provided with a recess 7 which extends from the interface 6 through the entire length of the sleeve and is shaped to allow a cable 2 fitted with a cable connector, in this example lug connector 4 to be inserted through the rear of the sleeve to the interface 6. Other suitable cable connectors are useable where such connectors provide a conducting surface suitable for connection to the present invention.

The recess 7 is provided with an abutment surface 9 which is designed to oppose movement of the electrical coupling means or terminal block 21 in a longitudinal direction through the first and second sleeves 3 and 5. In addition the recess 7 is shaped to allow the introduction of the lug 4 into the first sleeve in a specific orientation. It can be seen in figure 2 that the recess denoted by reference numeral 11 has a curved first portion and a straight sided second portion in which the sides are angled towards a flat top portion. This shape has been chosen to be similar to the shape of the lug connector used in this case. In addition to ensuring that the lug can only be introduced through the sleeve 3 or 5 in a specific orientation the shaped recess 11 prevents rotation of the cable in the sleeve 3 or 5.

Keying means are provided on the opposing surfaces of the first sleeve 3 and second sleeve 5 at the interface 6.

The keying means in this example consists of a pair of holes 14 and a pair of pins 17 located on the first sleeve and positioned to receive a similar pair of holes and pins positioned on the second sleeve 5.

Sealing ring 15 is provided on either the first sleeve 3 or second sleeve 5 and corresponding threads 16 are provided on both first sleeve 3 and second sleeve 5 such that when the jointing apparatus has been connected together to provide interface 6 a selling ring can be screwed in position across the interface in a position as shown in figure 1.

The ends of each of the first sleeve 3 and the second sleeve 5 are provided with a removable seal which consists of a rubber sealing ring 17 and a screw ring 19.

The screw ring 19 is provided with a passage 20 which is sized to accommodate a cable 2 and when the screw ring 19 is turned to move it towards the position of the interface 6 the rubber sealing ring 17 is compressed to form a tight seal between the cable, the tapered section 13 and the screw ring 19. In this example the seal is secure enough to protect the jointing apparatus from immersion in water and ensures environmental sealing to the known standard IP67.

Figures 3a and 3b illustrate the feature of the shaped recesses and the keying available using holes 14 and pins 12. Figure 3a shows the first sleeve 3 and the figure 3b shows the second sleeve 5. In addition, these figures have been positioned such that where the faces of figures 3a and 3b turned to face one another they would fit together in the manner intended to form the interface 6.

It can he seen therefore that a lug connector 4 in the first sleeve 3 would be positioned in a first orientation and a lug connector 4 in the second sleeve 5 would be positioned in the opposite orientations when connecting them together. Therefore, the actual cables 2 which are connected to the lug connectors 4 are substantially coaxial with respect to one another.

Figures 4 and 5 show the electrical coupling means or terminal block 21. In both of these figures an exploded view of the terminal block 21 is shown. The terminal block 21 comprises a central H shaped member 23 having a first surface 25 and a second surface 27. A central bolt receiving bore 29 is provided in the H shaped member 23.

The bolt retaining plate 35 is provided with a bolt 31 and a nut retaining plate 37 is provided with a nut 38.

The terminal block 21 is designed so that the bolt retaining plate fits through the hole in the lug connector of a cable 2 which is to be contained in the first sleeve. This is fitted to the first surface 27 of the H shaped member 23 by means of the bolt 31. The second lug connector 4 is attached to the first surface of the H shaped member 23 by means of the bolt and the nut retaining plate 37 is positioned on top of the lug connector 4. The lug connector 4 can then be attached to cable 2 which can be accommodated in the second sleeve 5.

The H shaped member 23 has been designed in order to maximise the contact area with the lug connector 4 maximizing this contact area provides for the best possible conductivity through the terminal block between lug connectors 4 maintained in respect of first and second sleeves 3 and 5. In addition, the geometry of the H shaped member 23 prevents and restricts rotation of the lugs 4 around the bolt 31.

In addition further keying means can be provided on the H S shaped section to ensure that the lugs 4 are attached to it in the correct orientation.

Figure 5 shows a second embodiment of the terminal block 21 of the present invention. In this embodiment positioning screws 39 are provided on the lateral portions of the H shaped member 23. These screws 39 are designed to further restrict the movement of the lugs 4 once they have been attached to the bolt through the central bolt receiving bore.

Figure 6 shows a further embodiment of the present invention in which a padlock 41 is fitted to the locking ring 15. The use of a padlock or other similar lock provides additional security and prevents unauthorized removal of the locking ring 15.

Figure 7 shows a further embodiment of the present invention in which an insulating extender piece 45 is positioned in a recess 43 formed in the first sleeve 3 and the second sleeve 5. The recess is located across the sleeve interface 6 and is constructed from insulating material. The insulating extender piece provides an added safety feature in that the insulation path is increased.

In addition, it allows the jointing apparatus to be used in high voltage applications of up to 20KVac.

In alternative embodiments, the insulating extender piece can be integrally formed in one sleeve with a corresponding recess in the other sleeve.

In another alternative embodiment, the locking ring is fitted with a bayonet or push-pull locking mechanism which provide convenient coupling of the first sleeve 3 and the second sleeve 5.

Use of the embodiment of the cable jointing apparatus shown in figure 1 will now be described. The cable jointing apparatus can be fitted to a pair of cables in the following manner.

Firstly, the cable 2 and lug connectors 4 are passed directly through the first and second sleeves 3 and 5.

When the first and second sleeves 3 and 5 have been fitted the lug connectors 4 (or cable end terminals) can now be connected. The lug connectors 4 are bolted into the terminal block 21. The bolt 31 is secured through the central bolt receiving bore 29 and the bolt 31 is tightened to secure the lug connectors 4 in position.

The first sleeve 3 and the second sleeve 5 are then brought together. The keying means provided by key pins 12 and holes 14 ensures that the first sleeve and the second sleeve connect together in a predetermined orientation. Once they have been connected together the locking ring 15 is screwed across the first sleeve 3 and second sleeve 5 and the ring is then tightened to provide a electrically insulating seal over the terminal block 21. Finally, the screw rings 19 provided on each of the first and second sleeves 3 and 5 is screwed in position forming a seal at either end of the jointing apparatus 1.

The present invention has a number of advantages with respect to the known prior art. Firstly because various lengths of cable can be used without removal of the lug connectors or cable end terminals an increase in the utilization of existing cables is achieved. In addition the present invention allows easy connection and S disconnection of cable lengths by a single operator and allows cable owners to standardize cable lengths and simply select these lengths for connection together depending on the overall length required for a job. The present invention further removes the need for the fabrication of bespoke junction boxes and removes the need for plug and socket connectors. In addition it is usable with standard cable end copper tube terminals and can tolerate 50000 amp short circuit environments.

The above example of the present invention is suitable for use with 300mm cable. The present invention is also applicable to other sizes of cable having larger or smaller cross sectional areas and diameters, with crimp lugs of various sizes and shapes and with other cable end terminals.

Improvements and modifications may be incorporated herein without deviating from the scope of the invention.

Claims

Claims 1. An electrical cable jointing apparatus for connecting together

electrical cables having cable connectors attached to the ends thereof, the jointing apparatus comprising electrical coupling means and electrical insulating means, the electrical insulating means having first and second mutually connectable sections, each of the first and second sections being provided with a recess shaped to accommodate at least part of the coupling means, wherein the coupling means is adapted to receive a first cable connector said cable connector being expendable through the first section of the insulating means and being adapted to receive a second cable connector expendable through the second section of the insulating means.
2. An electrical cable jointing apparatus as claimed in claim 1 wherein the recess is provided with an abutment to restrict longitudinal movement of the electrical coupling means.
3. An electrical cable jointing apparatus as claimed in claim 1 or claim 2 wherein the first and second mutually connectable sections are provided with keying means to allow' the connection together of the first and second sections in a predetermined orientation.
4. An electrical cable jointing apparatus as claimed in claim 3 wherein the keying means comprises at least two holes contained on opposing faces of first and second sections, the holes being adapted to receive pins on the second and first sections respectively.
5. An electrical cable jointing apparatus as claimed in any preceding claim wherein at least one of the recesses on the first and second sections is shaped to receive a cable connector in a predetermined orientation.
6. An electrical cable jointing apparatus as claimed in any of claims 1 to 4 wherein the first and second recesses are each shaped to receive a connector such that the electrical cables attached thereto are arranged substantially coaxial with respect to one another.
7. An electrical cable jointing apparatus as claimed in any preceding claim wherein the end of each of said first and second sections of the electrical insulating means remote from the opposing surfaces is provided with a removable seal.
8. An electrical cable jointing apparatus as claimed in claim 7 wherein the removable seal provided in each of the first and second sections is an outer screw ring and an inner sealing ring.
9. An electrical cable jointing apparatus as claimed in any preceding claim wherein a locking mechanism is provided on the first and second sections.
10. An electrical cable jointing apparatus as claimed in claim 9 wherein the locking mechanism comprises a locking ring and thread provided on the first and second sections respectively such that the locking ring is connectable to the screw thread.
11. An electrical cable jointing apparatus as claimed in claim 9 the locking mechanism comprises a bayonet or push pull connector.
12. An electrical cable jointing apparatus as claimed in any of claims 9 to 11 wherein the locking mechanism is further provided with a padlock.
13. An electrical cable jointing apparatus as claimed in any preceding claim wherein the electrical coupling means comprises a block having fastening means for fastening first and second connectors thereto. !!
14. An electrical cable jointing apparatus as claimed in claim 13 wherein the fastening means is provided by a bolt connectable through a plate in the fastening means and at least one other plate removably secured between the sides of the block.
15. An electrical cable jointing apparatus as claimed in any preceding claim wherein the electrical coupling means is provided with positioning means to ensure the correct positioning of the bolt in the fastening means.
16. An electrical cable jointing apparatus as claimed in claim 15 wherein the positioning means are screws.
17. An electrical cable jointing apparatus as claimed in any preceding claim, the jointing apparatus is designed for use with heavy duty power cables.
18. An electrical cable jointing apparatus as claimed in any preceding claim, wherein the jointing apparatus is - 1 designed for use with cables carrying currents of over 50amps.
19. An electrical cable jointing apparatus as claimed in any preceding claim, wherein the jointing apparatus is designed for use with cables carrying currents of over lOOamps.
20. An electrical cable jointing apparatus as hereinbefore described with reference to the accompanying drawings.

20. An electrical cable jointing apparatus as hereinbefore described with reference to the accompanying drawings. \]

Amendments to the claims have been filed as follows: 1. An electrical cable jointing apparatus for connecting together electrical cables having cable connectors attached to the ends thereof, the jointing apparatus comprising electrical coupling means and electrical insulating means, the electrical insulating means having first and second mutually connectable sections, each of the first and second sections being 1() provided with a recess shaped to accommodate at least part of the coupling means, the recess being provided with an abutment to restrict longitudinal movement of the electrical coupling means, wherein the coupling means is adapted to receive a first cable connector said cable connector being expendable through the first section of the insulating means and being adapted to receive a second cable connector expendable through the second section of the insulating means.

2. An electrical cable jointing apparatus as claimed in claim wherein the recess restricts rotational movement of the electrical coupling means.

3. An electrical cable jointing apparatus as claimed in claim 1 or claim 2 wherein the first and second mutually connectable sections are provided with keying means to allow the connection together of the first and second sections in a predetermined orientation.

3() 4. An electrical cable jointing apparatus as claimed in claim 3 wherein the keying means comprises at least two holes contained on opposing faces of first and second sections, the holes being adapted to receive pins on the second and first sections respectively.

5. An electrical cable jointing apparatus as claimed in any preceding claim wherein at least one of the recesses on the first and second sections is shaped to receive a cable connector in a predetermined orientation.

6. An electrical cable jointing apparatus as claimed in any of claims 1 to 4 wherein the first and second recesses are each shaped to receive a connector such that the electrical cables attached thereto are arranged substantially coaxial with respect to one another.

7. An electrical cable jointing apparatus as claimed in any preceding claim wherein the end of each of said first and second sections of the electrical insulating means remote from the opposing surfaces is provided with a removable seal.

8. An electrical cable jointing apparatus as claimed in claim 7 wherein the removable seal provided in each of the first and second sections-is an outer screw ring and an inner sealing ring.

9. An electrical cable jointing apparatus as claimed in any preceding claim wherein a locking mechanism is provided on the first and second sections.

10. An electrical cable jointing apparatus as claimed in claim 9 wherein the locking mechanism comprises a locking ring and thread provided on the first and second sections respectively such that the locking ring is connectable to the screw thread.

11. An electrical cable jointing apparatus as claimed in claim 9 the locking mechanism comprises a bayonet or push pull connector.

12. An electrical cable jointing apparatus as claimed in any of claims 9 to 11 wherein the locking mechanism is further provided with a padlock.

13. An electrical cable jointing apparatus as claimed in any preceding claim wherein the electrical coupling means comprises a block having fastening means for fastening first and second connectors thereto. ,! 14. An electrical cable jointing apparatus as claimed in claim 13 wherein the fastening means is provided by a bolt connectable through a plate in the fastening means and at least one other plate removably secured between the sides of the block.

15. An electrical cable jointing apparatus as claimed in any preceding claim wherein the electrical coupling means is provided with positioning means to ensure the correct positioning of the bolt in the fastening means.

16. An electrical cable jointing apparatus as claimed in claim 15 wherein the positioning means are screws.

17. An electrical cable jointing apparatus as claimed in any preceding claim, the jointing apparatus is designed for use with heavy duty power cables.

18. An electrical cable jointing apparatus as claimed in any preceding claim, wherein the jointing apparatus is designed for use with cables carrying currents of over 50amps.

19. An electrical cable jointing apparatus as claimed in any preceding claim, wherein the jointing apparatus is designed for use with cables carrying currents of over lOOamps.