WO2007000016A1

WO2007000016A1 - Cable reeler and cable retrieval method

Info

Publication number: WO2007000016A1
Application number: PCT/AU2006/000893
Authority: WO
Inventors: Michael John Gray; Anthony Hector Percival
Original assignee: Amakye Engineering Pty Limited
Priority date: 2005-06-27
Filing date: 2006-06-26
Publication date: 2007-01-04
Also published as: AU2005202796A1; AU2005202796B2; AU2012203823A1

Abstract

A power cable reeler (108, 110, 120) including a cable reel (204) mounted on a movable base (210), the cable reel (204) being adapted to take up or deploy cable (206) as the movable base (210) moves. Also disclosed is a power cable reeler (112) adapted to feed a cable (126) over a rim of a mine high wall (124), the reeler (112) including an arm (114) mounted on a base, the arm (114) being inclined to project over the rim of the wall (124), the arm (114) being adapted (116) to support a cable (126) at the free end of the arm (114). A method of operating a mine having a workface using a mining equipment (102) connected to a power cable (206), the power cable (206) including a series of two or more cable segments, each cable segment being connected to a reel (204) of one cable reeler to a connector connected to an adjacent cable reeler, each cable reeler having a controllable motorized cable reel (216, 218), the method including supplying power to the mining equipment (102) via the cable (206), moving the mining equipment (012) along the workface; and reeling in the deployed cable (206) at a rate which approximates the speed of movement of the mining equipment (102) along the workface. Also disclosed are connectors between cable connector sections adapted to rotate relative to their mating contacts in a second connector section.

Description

Cable reeler and cable retrieval method

Field of the invention

[001] This invention relates to the control and management of power supply cables for equipment which is remote from the source of power so that the power needs to be fed to the equipment via a cable. In particular, the invention is applicable in strip/open cut mines. The invention provides a cable^* deploying and retrieving sled which is adapted to facilitate the deployment and retrieval of power cables in a strip/open cut mine. The invention also enables the implementation of improved methods of deploying cable and operating equipment fed by long lengths of cable.

Background of the invention

[002] hi strip/open cut mines, a working face can extend for over 2 km. The working face is blasted to dislodge the ore/overburden which collapses at the working face. Mining equipment such as draglines or face shovels are used to collect the ore/overburden by scooping the bucket through the ore/overburden. The term mining machine will be used generally to refer to the equipment which is used to move the blasted ore unless the context requires otherwise. Mining machines in strip/open cut mines are powered by electricity, whereby the mining equipment will use electric motors to produce the motive power. This requires large amounts of power and this is usually provided via^' a high voltage supply cable to reduce current. For example, the voltage maybe 6.6 kV.

[003] hi order for the mining equipment to be able to move along the work face, there must be sufficient cable available to permit travel over the full length of the face. The cable is ran across the floor of the mine with the length of cable on the floor of the strip/open cut mine sometimes exceeding 2700 m. Such a cable can include one or more connectors. Large installations may include up to 14 connections

[004] The floor is earth and the power cables can become covered in the earth, hi operation, the mining equipment is located at the start of a run and the cable is deployed parallel to the line of the mining equipment run. While the power cable may initially be deployed at a safe distance from the intended path of the mining equipment, in practice, the power cable can be damaged by the mining equipment or other vehicles. For example, the mining equipment may deviate from the initial path. Furthermore, as the dragline advances or the face shovel retreats, the connection point of the power cable to the mining equipment overlaps the deployed power cable forming a loop in the cable. The power cable is fairly heavy and stiff and the resulting loop can cause the cable to move. Accordingly, the power cable may move into the path of the mining equipment. As the operation progresses the power cable is dragged into loops along side each other causing bunching of the cable on the mine floor which increases the risk of being run over by heavy vehicles as well as cuts, abrasions, thinning of the outer sheath and tighter than recommended bend radius due to the dragging. The damage to the power cable presents a safety hazard as the high voltage wires can be exposed.

[005] m addition, the working area of a strip/open cut mine is continually traversed by vehicles. As already mentioned, the vehicles can include excavators, haul trucks and dozers and other machines also moving across the floor of the mine. The vision of drivers of these vehicles can be restricted or the power cable may be buried. Thus cables and connector plugs are prone to damage by being run over by the equipment being driven on the mine floor. When this occurs, the wires of the cable can become exposed or the cable can be shorted. This can interrupt the operation of the mining equipment causing down time as well as damage to equipment. Again, the exposure of live wires can present a safety hazard.

[006] In some instances, the cable may be fed over the edge of the mine high wall as the cable enters the strip/open cut mine. The cable can be abraded on the edge of the wall, again leading to exposed wires and possible short circuits.

[007] Any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates, at the priority date of this application.

Summary of the invention

[008] It is thus desirable to reduce the incidence of damage to the power cables. [009] According to an embodiment of this invention there is provided a cable deploying sled having a cable reel from which the cable can be deployed, the reel being controllable to roll up the cable to minimize the length of cable deployed during operation.

[010] The cable reeler can include a set of slip rings to decouple the rotation of the cable from a non-rotating connector.

[011] The cable can be live while it is being rolled up or deployed.

[012] The cable can be rolled up or deployed while it is being used to deliver power, to the equipment.

[013] According to a further embodiment of the invention, there is provided a power cable reeler including a cable reel mounted on a moveable base, the cable reel being adapted to take up cable at a rate approximating the speed of the mining equipment or bulldozer.

[014] The reeler can include a cable indexer adapted to lay the cable on the reel as the cable is taken up.

[015] The cable indexer can be adapted to move parallel to the axis of the reel and to move in synchronism with the take up point on the reel to ensure that coils of the cable are properly nested in one or more layers on the reel as the cable is taken up.

[016] The reeler can include a roller path adapted to deploy the cable over a side of the reeler and to take up the cable as it is being reeled in.

[017] The cable roller path can be adapted to deploy the cable substantially parallel to the direction in which the reeler is moving.

[018] The roller path and the cable indexer can be j oined.

[019] The cable indexer can be a narrow channel.

[020] The roller path can be a diverging channel.

[021] The indexer can be arranged to present a duct oriented so that the cable between the reel and the indexer is substantially tangential to the reel.

[022] According to a further embodiment of the invention, a power cable reeler can be adapted to feed a cable over a rim of a vertical or near vertical mine high wall.

[023] The reeler can include an arm mounted on a swivel base, the arm being arranged to project over the rim of the high wall, the arm being adapted to support a cable at the free end of the arm.

[024] The arm can include a pulley at the free end of the arm to carry the cable. [025] The reeler can include a cable reel.

[026] The high wall reeler can be positioned with the boom over the cutting edge, with the ability to swivel while keeping the sled parallel to the edge.

[027] The invention also provides a method of operating a mine having a workface using a mining equipment powered via a power cable, the power cable being deployed adjacent to the workface in sections between cable reelers of a series of two or more cable reelers including at least a first cable reeler and a second cable reeler, the method including: connecting the mining equipment to a first end of a deployed power cable, the second end of the deployed power cable being connected to the power cable reeler of a first cable reeler having a controllable motorized cable reel; moving the mining equipment along the workface; moving the first reeler along the workface, and reeling in the deployed cable between the first cable reeler and the second cable reeler at a rate compatible with the speed of movement of the mining equipment along the workface.

[028] The first reeler is connected to the mining equipment via a tub line which permits variation of the distance between the reeler and the mining equipment. The first reeler and the mining equipment should be maintained at a distance which prevents the tub line from becoming entangled with the mining equipment.

[029] , According to a further embodiment of the invention, there is provided a method of deploying the dragline cable (tub cable)/face shovel cable to the connector plug on the cable reeler sled which runs parallel to the intended direction of travel of the mining equipment; the method including locating the first reeler in a deployment position in front of the mining equipment; advancing the mining equipment towards the first cable reeler; moving first cable reeler towards the second cable reeler; and reeling in the cable between the first and second cable reelers at a speed compatible with the speed of the first cable reeler.

[030] The method can also include joining a first cable reeler to a second reeler when the first reeler has been brought into proximity with the second cable reeler moving the joined cable reelers while taking up the cable on the second cable reeler.

[031] Depending on size and power of the bulldozer and the cable reeler size, this step can be repeated with subsequent cable reelers.

[032] This collation of cable reelers is practicable because each reeler takes up its deployed cable as it is moved towards the succeeding cable reeler. [033] The cable can be taken up at a rate approximately equal to or less than a slow travel speed of the bulldozer.

[034] There can be more than 5 reelers in line connected between the first reeler and a power source, the method including locating the intermediate reelers at locations along the intended travel path of the mining equipment; connecting the cable from the second reeler to the first reeler; and deploying or taking up the cable between the first reeler and the second reeler as required when the first reeler is moved.

[035] According to further embodiment of the invention, there is provided a method of deploying a face shovel cable to a connector plug on the cable reeler sled, as the face shovel advances in a forward direction the cable reeler sled is towed behind the face shovel via connecting/tow chains, during this process the cable on the first cable drum is deployed parallel to the direction of travel of the face shovel.

[036] The power cable connection between the face shovel and the first cable reeler can be done using various methods. For example, the cable from the face shovels car body can be placed along the tow chains directly to the connector plug on the rear of the first cable reeler.

[037] Alternatively, the cable from the face shovel car body can run along a stinger joining to the connector plug on the first cable reeler.

[038] hi a further alternative, the face shovel having its original cable reeler fitted to the car body has its connector plug connecting to the connector plug on the rear of the first cable reeler, in this method when the drum on the first cable reeler is unwound the tow chains can be dropped off allowing the face shovel to continue its production on its own cable reeler connected to the car body.

[039] According to further embodiment of the invention, in which a face shovel retreats along a workface, there is provided a method including the. steps of: winding the cable connected to the face shovel onto a cable reel of the face shovel as the face shovel retreats along the workface; when the face shovel is in proximity to the first cable reeler, connecting the face shovel to the first reeler and moving the first cable reeler and face shovel while reeling in the cable from the first cable reeler.

Brief description of the drawings [040] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[041] Figure 1 is a schematic view of the layout of an exemplary open cut mine;

[042] Figure 2 is a side view of a cable deploying sled;

[043] Figure 3 is a front view of a cable deploying sled;

[044] Figure 4 is a perspective view of the cable reel and cable indexer.

[045] Figure 5 shows a cable sled adapted for feeding cable over the rim of a mine high wall;

[046] Figure 6 illustrates a method of operating the cable retrieval system in a dragline straight run according to an embodiment of the invention.

[047] Figure 7 illustrates a method of operating the cable retrieval system over multi- bench drops in a mine according to an embodiment of the invention.

[048] Figure 8 illustrates a method of operating the cable retrieval system with a face shovel in a mine according to an embodiment of the invention.

[049] Figure 9 illustrates an alternative method of operating mining equipment;

[050] Figure 10 illustrates another method of operating mining equipment;

[051] Figure ,11 illustrates a further method of operating mining equipment;

[052] Figure 12 is illustrative of a 3 wire slip ring assembly;

[053] Figure 13 is illustrative of a rotation decoupling connector.

Detailed description of the embodiment or embodiments

[054] Figure 1 shows a schematic view of a strip mine layout using a dragline 102 fed through an electricity cable from an electricity substation 122 via a number of cable reel sleds 108, 110, 120, and high wall gantry 112.

[055] The sleds 108, 110, 120 each carry a cable reel. These reels can be arranged with the reel axis parallel with the sled skids as shown in Figures 2 & 3. This arrangement enables the deployment of the cable over the side of the sled as it is being drawn along by a bulldozer. [056] While the workface is shown as being at the base of wall 104 opposite to the high wall 124, it can also be at the base of the high wall 124. [057] Figure 2 shows a schematic view of a mining equipment power cable reeler. This includes a sled having skids 210. A platform (304 in Figure 3) mounted on the skids supports a cable reel 204 via support posts 212, 214. Cable 206 passes through slip rings 1204. The cable is wound onto or drawn from the cable reel 204 as required. A motor 216 and drive unit/torque converter 218 are provided to operate the reel to lay out or take up cable as required. The drive unit can be either hydraulic or electric motor.

[058] A cable indexer 222 is provided to ensure the cable is wound onto the reel 204 in orderly layers and to facilitate deployment of the cable without tangling of the cable. The indexer can be combined with a cable roller path 220 to form a cable guide 208. The cable guide

208 is similar to a funnel split along its axis and having a broad end 220 and a narrow end 222 forming a half spout. The cable guide 208 is provided with walls 224, 226 to control the cable as it is drawn off or reeled in. The edges of the roller path can have rollers (not shown) to avoid damage to the cable. The funnel shape facilitates the rolling out or reeling in of cable in either direction depending on the direction of travel of the cable reeler.

[059] As best shown in Figure 3, the cable indexer 222 is in the equivalent to the "spout" of the funnel and is curved towards the reel 204. Preferably the spout 222 is aligned approximately tangential to the reel 204 so the cable is approximately aligned between the reel

204 and the spout 222. As the end of the funnel 222 is spaced from the reel, it is slightly lower than the upper edge of the reel 204.

[060] As best seen in Figure 4, in the cable deploying mode, the cable guide 208 serves to distribute cable 408 in a direction substantially parallel to the direction of movement of the sled as indicated by arrow 410. The axis of the reel 204 can be parallel to the direction of movement 410.

[061] The cable indexer 222 roller path 220 cable guide 208 can be adapted to traverse the length of the reel 204 so that the take up point is adjacent the cable coil and takes up the cable without pulling the cable axially. This reduces the chance of excessive twisting or tangling of the cable.

[062] In Figure 3 the cable indexer 222 roller path 220 cable guide 208 is mounted on a support 302. The support can be mounted on a transport means 306 which enables the indexer

222 roller path 220 cable guide 208 to traverse the length of the reel 204 in both directions while taking up or deploying the cable. The transport 306 can be synchronized with the cable take up or deployment so that the indexer 222 is adjacent to the take up or deployment point of the cable during cable take up or deployment, hi one embodiment, the transport means can be a screw threaded rod and gear or chain driven.

[063] Figure 12 illustrates the function of a slip ring assembly or commutator 1200 which can be used to decouple the rotation of a cable 1212 being deployed or reeled in from a non-rotating connection 1230.

[064] The slip rings 1204, 1206, 1208 are mounted on the reeler shaft 1210 and are electrically isolated from the shaft and from each other. The cable 1212 is the cable on the reel of the cable reeler. This cable has a plug 1214 which connects with socket 1216 which rotates with the slip rings, although the plug can instead be on the shaft and the sopket on the cable. Electrical conducting brushes 1224, 1226, 1228 are in contact with corresponding ones of the slip rings

1204, 1206, 1208. The brushes are under spring pressure to maintain good electrical contact with the slip rings. The brushes are non-rotating, so as the slip rings rotate with the shaft 1210, electrical current can pass between the stationary brushes and the rotating slip rings. The brushes are connected to socket 1230 to which a cable 1234 can be connected by plug 1232.

[065] Connector 1230 can be mounted on a non-rotating portion of the cable reeler so that the cable 1232 from another cable reeler can be connected to the cable 1212 via the commutator.

[066] Of course the plugs and sockets can be interchanged so that, for example, plug

1232 can be a socket and 1230 can be a plug. When 1232 is a socket and 1214 is a plug, the cable

1212 can be connected directly to cable 1234 when cable 1212 is not being wound onto or from a reel, hi the absence of the commutator 1200, the cable 1212 on the reel can only be connected to another cable 1234 when the reel cable 1212 has been reeled in or played out, but the connection cannot be maintained during the reeling in or playing out of the cable. Thus the use of the commutator enables cables to be connected while the cable is being reeled in or played out.

[067] The power to operate the cable reeler motor and controls can be taken from the non-rotating side of the commutator.

[068] hi a further embodiment of the invention, the connector plugs or sockets can be fitted with commutators to permit any cable windup due to the reeling in or playing out of the cable to be isolated. [069] Figure 13 illustrates schematically a slip ring connector 1300. Assume a cable consisting of wires 1320, 1322 is subject to twisting. The wires 1320 1322, are connected to a freely rotatable slip ring arrangement 1306 with wire 1320 connected to the outer slip ring 1308, and wire 1322 connected to the inner slip ring 1310. The slip rings 1308, 1310 are insulated from one another as indicated by insulation 1312. The slip ring arrangement 1306 is free to rotate in connector housing 1302 and can be insulated therefrom as indicated by insulated bearings 1324, 1326. The cable made up of wires 1320, 1322 enters the housing 1302 via aperture 1318, which may include a rotating grommet arrangement (not shown).

[070] In the mating connector section contained in housing 1304, brushes 1314, 1316 make spring contact with the corresponding slip rings 1308, 1310. Thus the cable connected to the brushes 1314, 1316 is decoupled from any twist associated with cable 1320, 1322. [071] In the embodiment illustrated, the housing parts 1302, 1304 can be connected together as neither part needs to rotate. However, the rotation can also be built into the connection between the housing components so that, for example, the commutator arrangement 1306 can be fixed in relation to the housing 1302, and the connection between housing parts 1302 and 1304 can permit housing part 1302 to rotate in relation to housing part 1304. [072] Figure 13 is illustrative of the functional principles of the twist decoupling connector 1300. The physical details of the connector are not illustrated. While the commutator is shown as working on the disc face of the slip ring arrangement, it can equally be arranged to work with cylindrical faces. While a two wire cable is illustrated, the principle can be applied to cables with three or more wires.

[073] The torque converter 218 operates automatically to reel in or lay out cable as required. Alternatively, the speed of the cable reel can be controlled by the speed of the bulldozer. When the bulldozer is traveling at a fast speed it will trip a slack cable sensor in the cable guide and show up a red warning light, when the bulldozer slows down and the slack cable sensor indicates an appropriate cable tension, a green light will show. These lights can be located on top of the machine.

[074] Figure 4 illustrates the reel 204 and the indexer 222 roller path 220 cable guide 208 in a perspective view. Rims 404, 406 are provided on each end of the reel 204 to retain the cable on the reel. A slip ring 412 of a commutator can be connected to the shaft 414 of the reel to provide a connection from the cable on the reel to a non-rotating connector (see Figure 12). [075] Figure 5 shows a further embodiment of a cable sled adapted to feed the power cable over the rim of a mine high wall. A sled 504 carries a cable reel 502 and an arm 506. The arm 506 can be inclined at an angle to project beyond the edge 514 of the mine's high wall. A pulley 508 is attached to the remote end of the arm 506. The cable 510 runs from the reel 502 over the pulley 508 and is suspended beyond the high wall 514. A motor 524 and gearbox 520 can be provided to operate the cable reel 502 as well as a counter weight 522.

[076] The cable reeler described above facilitates improved methods of operating an open cut mine using an electrically powered face shovel or dragline. The cable reelers can be used to deploy and reel in the power cable while it is live and feeding power to the mining equipment.

[077] Figure 6 illustrates a first method of operating a mine according to an embodiment of the invention.

[078] In Figure 6, a dragline 602 is connected to the power supply substation 624 through a number of power cable reelers 614, 612, 610 via cables tub cable 626, and cable reeler cables 628, 630, 632, the cables from each power cable reeler having been previously deployed by hauling the reelers into position 610, 612, 614 from the substation outwards to the draglines working face when the dragline walks to the location. The tub cable 626 is of the order of 300m long and provides a safe working distance between the drag line 602 and the first cable reeler 610 while allowing the distance between the drag line 602 and the cable reeler 610 to vary.

[079] hi some applications the tub cable can be associated with a stringer cable of a slightly shorter length to prevent tension being applied to the tub cable.

[080] The left-sloping shaded dragline is shown as having been moved to position 604, which, for the sake of clarity has been moved up the page to avoid overlap with the bulldozer 616 and cable reeler 610, but in reality would remain on the workface as indicated by arrow 605. At the same time the cable reeler 610 has been hauled by bulldozer 616 to position 610' (left shaded item), and the dragline at 604 is still connected to the cable reeler in its new position at 610'.

While it is being moved, the cable reeler 610 reels in its cable 628. As the cable reeler reaches position 610', the bulldozer is uncoupled from the cable reeler at 610' and coupled to cable reeler

612, while cable reeler 610' is coupled to cable reeler 612. Thus the bulldozer is connected to haul the two cable reelers 610 and 612 without the need to switch off the power or uncouple the electrical connection between cable reelers 610 and 612. [081] This process may continue depending on bulldozer/cable reeler sizes pulling cable reelers 610, 612, 614 back towards substation 624.

[082] At any point full cable reelers may be taken out of the circuit. Power is switched off and the mining machine is shut down for a brief period while cable reelers are taken out of line. All cables may be stored on their associated cable reelers.

[083] The process is reversed for walking a dragline out from the substation to the work face.

[084] Figure 7 shows a schematic view of an alternative mode of operation of mining equipment using the power cable reeler. one feature of the embodiment of figure 7 is the use of the high wall gantry reeler 732 to lower the cable 730 over the high wall 740. The electricity substation 734 supplies electricity to gantry cable reeler 732. One or more power cable reelers can be included between the substation 734 and the high wall cable gantry 732. The power cable connects to a power cable reeler 724 via connector plug 728. In this embodiment, the cable reelers can be connected so that at least one of the cable reelers acts first to reel in cable and then to play^' out cable while the mining equipment 702 is moving along the mine face. In the embodiment illustrated in Figure 7, the cable reeler 708 is connected by tub cable 714 to mining machine 702. on its other side, the cable reeler 708 is connected to cable reeler 724 via deployed cable 718, which is connected to the reel of cable reeler 708. As the mining machine 702 moves along the workface 742 towards cable reeler 708, cable reeler 708 also moves in the same direction as the mining machine and reels in its cable 718.

[085] As cable reeler 708 passes cable reeler 724, it changes from reeling in mode to deployment mode and plays out its cable 722. Thus the mining machine 702 can travel about twice the length of the cable on reeler 708 using this method.

[086] Again, the cable reeler 706 can previously have been located at the right hand extremity of cable 730, and the same mode of operation can have taken place, so that a pair of cable reelers can cover a substantial distance with minimal interruption to the mining operation.

[087] Figure 8 illustrates an embodiment of the mode of operation of a face shovel using the power cable reeler operating at a work face.

[088] Face shovel 801 running through the cable reelers 810, 812 & cables 828, 830,

Figure 8 shows face shovel 801 operating without its own power cable reeler while showing the method of utilizing the power cable reeler, where a small power cable 829 is run from the face shovel car body supported along the tow chains 880 to the connector plug on the rear of the cable reeler 810. As the face shovel 801 advances along the working face the cable reeler is towed behind.

[089] Figure 9 shows an embodiment of a face shovel 901 powered through the cable reelers 910, 912 & cables 928, 930. Face shovel 901 is shown operating without its own power cable reeler. A small power cable 929 is run from the face shovel car body across a stinger arm

940 to the cable reeler 910. With this method the cable reeler 910 is still towed behind the face shovel 901 by the tow chains.

[090] Figure 10 shows face shovel 1001 running through the cable reelers 1010, 1012 & cables (1027 shovel cable) 1028, 1030. Face shovel 1001 is shown operating with it own cable reeler in conjunction with the cable reeling system of the present invention. The method includes towing the cable reeler 1010 behind face shovel 1001 with tow chains 1080. With progression along the work face the face shovel 1001 advances until the cable reeler has been run off, i.e., to the full length of cable on the cable reeler. Face shovel 1001 drops the tow chains 1080 and continues along the work face on its own cable 1027.

[091] The method of retreating along the work face with a face shovel by the Face

Shovel 1101 retreating winding up its own cable 1127 until it reaches the cable reeler 1110 the tow chains 1180 can be reconnected from cable reeler 1110 to Face Shovel 1101. Bulldozer or rubber tired dozer 1118 is connected to the cable reeler 1110 by tow chains 1181 and hauled back towards cable reeler 1112 while cable reeler 1110 rolls up cable 1128.

[092] The advantage of this method of operation is that it substantially eliminates the possibility of the mining equipment running over the power cable. However, the bulldozer must be operated carefully to avoid the cable. Nevertheless, the take-up of the cable reduces the chance of the cable looping and moving into the path of the bulldozer, as well as reducing the requirement for manual handling of cable.

[093] At all times, appropriate safety precautions need to be observed because of the inherent dangers of large moving vehicles, high voltage cables potentially unstable ground, and falling rocks. Typical working instructions are:

Select and clean the site for mining equipment cable reeler to operate;

Complete Statutory 103 inspection on Cable Reeler (visual check on machine c/w water, oil, fuel); Turn motor/generator switch to ON (red light will illuminate);

Select winding motion (siren will sound for 5 seconds *2) and flashing light will come on;

Carry out prescribed inspection (103 inspection) on bulldozer.;

Position bulldozer in place ;

Connect chains to towing points;

Commence towing at 5 kph;

Drag cable Reeler into position;

Disembark bulldozer and perform reverse procedure to shut down Cable Reeler;

Push stop button or turn key switch on the Cable Reeler to OFF;

Remove tow chains from bulldozer

Move bulldozer to suitable location and park fundamentally stable.

[094] While the reelers have been described as having skids, other means of facilitating movement, such as wheels or caterpillar tracks are within the scope of the invention. The cable reeler platforms can also have a motorized propulsion system to enable the cable reeler to move itself, eliminating the need for a bulldozer to haul the reeler. Power for the propulsion system can be delivered by the power cable, so that the reeler may still be hauled by bulldozer when not connected to the power supply.

[095] Where ever it is used, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of. A corresponding meaning is to be attributed to the corresponding words "comprise", "comprised" and "comprises" where they appear.

[096] It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text. All of these different combinations constitute various alternative aspects of the invention. [097] While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, and all modifications which would be obvious to those skilled in the art are therefore intended to be embraced therein.

Claims

1. A power cable reeler including a cable reel mounted on a moveable base, the cable reel being adapted to take up or deploy cable as the movable base moves.

2. A cable reeler as claimed in claim 1, including a rotation decoupler connected to an end of the cable.

3. A reeler as claimed in claim 1, including a cable indexer adapted to lay the cable on the reel as the cable is taken up.

4. A reeler as claimed in claim 3, wherein the cable indexer is adapted to move parallel to the axis of the reel and to move in synchronism with the take up point on the reel to ensure that coils of the cable are properly nested in one or more layers on the reel as the cable is taken up.

5. A reeler as claimed in any one of the preceding claims, including a cable roller path adapted to deploy the cable over a side of the reeler.

6. A reeler as claimed in claim 5, wherein the cable roller path deploys the cable substantially parallel to the direction in which the reeler is moving.

7. A reeler as claimed in any one of claims 5 or 6, wherein the cable indexer and the cable roller path are joined.

8. A reeler as claimed in claim 7, wherein the cable indexer is a narrow channel and wherein the cable roller path is a diverging channel.

9. A reeler as claimed in any one of claims 3 to 8, wherein the indexer is arranged to present a duct substantially tangential to the reel.

10. A power cable reeler adapted to feed a cable over a rim of a mine high wall, the reeler including an arm mounted on a base, the arm being inclined to project over the rim of the wall, the arm being adapted to support a cable at the free end of the arm.

11. A reeler as claimed in claim 10, wherein the arm includes a pulley at the free end of the arm to carry the cable.

12. A reeler as claimed in claim 10 or claim 11, wherein the reeler includes a transverse cable reel mounted with its axis of rotation transverse to the arm.

13. A power cable reeler as claimed in any one of the preceding claims, wherein the reeler includes a motorized propulsion system.

14. A method of operating a mine having a workface using a mining equipment connected to a power cable, the power cable including a series of two or more cable segments, each cable segment being connected from the reel of one cable reeler to a connector connected to a an adjacent cable reeler, each cable reeler having a controllable motorized cable reel, the method including: supplying power to the mining equipment via the cable, moving the mining equipment along the workface; and reeling in the deployed cable at a rate which approximates the speed of movement of the mining equipment along the workface.

15. A method of deploying power cable from a first reeler as claimed in any one of claims 1 to 9, to mining equipment, the method including: locating the first reeler in a connection position behind the mining equipment, the first reeler having a length of cable stored on its reel; connecting the power cable from the first reeler to the mining equipment; the method subsequently including one or more iterations of the following steps; driving the mining equipment to a distance less than or equal to the available portion of the stored length of cable while deploying the cable from the first reeler; moving the reeler up to or away from the connection position behind the mining equipment while taking up the cable on the reel.

16. A method as claimed in claim 15, wherein the cable is taken up at a rate approximately equal to or less than the travel speed of the first reeler.

17. A method of deploying a power cable as claimed in claim 14 or claim 15, wherein there is at least one or more reelers connected between the first reeler and a power source, the method including locating an second reeler at a location along the intended travel path of the mining equipment and spaced therefrom by a distance sufficient to permit the first reeler and the mining equipment to move between the second reeler and the workface; connecting the cable from the second reeler to the first reeler; and deploying or taking up the cable between the first reeler and the second reeler as required when the first reeler is moved.

18. An electrical connector having a commutator having first and second connector sections, each containing electrical contacts adapted to make electrical contact with contacts in the other connector section, wherein, the connectors in one connector section are adapted to rotate relative to their mating contacts in the second connector section.

19. A power cable reeler as herein described with reference to the accompanying drawings.

20. A method of deploying a power cable substantially as herein described with reference to the accompanying drawings.

21 An electrical connector including a commutator arrangement substantially as herein described with reference to Figure 13.