TITLE OF INVENTION
Outdoor Lighting Unit TECHNICAL FIELD
[0001] This invention concerns outdoor lighting equipment for outdoor sites such as open cast mines.
[0002] This type of mine when viewed in section has a series of descending steps, each step having a flat part skirted by an inclined wall. At night floodlights enable work to continue. Such lighting is provided by a mixture of static lighting and mobile lighting and it is to the latter that this invention is directed. Presently available lighting units cannot illuminate downwards beyond the third wall. The fourth wall remains in shadow. As much as 10-12 hours of the working day requires illumination, access to floodlighting can alter productivity.
BACKGROUND
[0003] It is known for mobile lighting units to be constructed as trailers with wheels and a motor driven generator which supplies power to floodlights mounted on a vertical post. These units have integral fuel tanks which must be replenished onsite. As the operational site moves, so must the unit. The units are adapted for downlighting, whereas it may be more useful to flood the inclined wall face.
SUMMARY OF INVENTION
[0004] One apparatus aspect of the invention provides apparatus for positioning and powering an outdoor lighting unit in order inter alia to illuminate the wall face of an open cut mine, comprising a vehicle with a reel which accommodates a protective hose containing an electrical cable, a self-propelled lighting tower carried by the vehicle and connected to the hose, the lighting tower being operable to advance from the vehicle to the site where illumination is required and to be retracted by hose movement toward the vehicle, and an optional electrical generator for supplying power to the unit via the cable.
[0005] Preferably the apparatus has its own electrical generator for the lights. The generator conveniently provides power to the self-propelled lighting tower through the same cable.
[0006] The unit may have a steerable wheel or wheels and its own motor for advancing the unit to the target site.
[0007] The vehicle will normally be a trailer which is towable to the area of operation where it remains static while the unit travels to the target site. Alternatively the trailer is a sled with a push bar and a bash plate.
[0008] The trailer preferably supports a reel drive. For convenience a standard hydraulic pump and motor provide the drive. Although the use of a single hose to contain both electrical cable and safety line is feasible, we prefer to use twin hoses on side by side reels using a common drive, one hose containing the electrical cable while the other hose contains the safety line. Both are connected to the lighting tower.
[0009] The hose may be of the type used to protect lines and conduits in areas where excavation occurs and the ground may be broken or where vehicles may do damage by being driven over the lines or conduits. The hose may be 50- 100mm in diameter. The safety line may be a light hawser.
[0010] The hose is made of polyethylene and resists crushing while being pliable enough to coil around a drum of 1.5-2m diameter.
[0011] The hydraulic drive may be powered by an internal combustion engine carried on the vehicle with a fuel tank for sustained nighttime operations. The reel may have sufficient hose for a unit range of 100-200m or any length of hose as desired by the purchaser/user. [0012] The lighting unit preferably has a video camera which points in advance of the unit. A display screen in a console on the static apparatus allows the operator to stand at the console and view the progress of the descending unit. Remote controls may be used to instruct the lighting tower's travel motor and servos as desired.
Advantageous Effects of Invention
[0013] 1. The floods can illuminate the sloping face from above or below.
[0014] 2. The power cable is safe from damage on the ground which normally prevents its use.
[0015] 3. The lighting unit can be more advantageously sited than known units which require a heavy motor and generator.
BRIEF DESCRIPTION OF DRAWINGS
[0016] One embodiment of the invention is now described with reference to the accompanying drawings, in which:
[0017] Figure 1 is an overhead perspective view of the apparatus ready to be towed to a location with the lighting cart on board.
[0018] Figure 2 is a perspective of the rear end of the trailer showing the reel drive.
[0019] Figure 3 is the same as Figure 2 but showing the housing side of the reel and the control console.
[0020] Figure 4 is a side view of the lighting cart.
[0021 ] Figure 5 is a perspective of the cart riding over dirt at the foot of an inclined face. [0022] Figure 6 is a perspective of the lighting cart at the top of an inclined face.
DESCRIPTION OF EMBODIMENTS
[0023] Referring to Figures 1-3 of the drawings, trailer 2 has a heavy duty platform 4 ono two pairs of tyred wheels 6 and an A-frame 8 for connection to a towing vehicle (not shown), preferably a four wheel drive vehicle.
[0024] A front stabiliser 10 (see Figure 3) and a corresponding pair of hydraulic stabilisers 12 allow the trailer to be raised off the wheels to act as an anchor when the mobile lighting cart 14 is travelling.
[0025] Trailer platform 4 has a hinged ramp 16 at the rear end and a reel assembly at the leading end. The reel assembly consists of a support frame 18 for horizontal reel 20 which has a central divider 22. The reel accommodates two side by side polyethylene hoses 24, 26, 100mm in diameter which serve to protect an electric cable about 110m in length. The remaining hose contains a light hawser 28 of the same length. The electric cable passes through a rotatable electrical contact where it exits the reel in order to receive current continually in known manner.
[0026] The assembly also has a housing 30 beside the support frame containing a diesel engine, a hydraulic pump, an electric generator and a fuel tank. Figure 2 shows hydraulic motor 32 attached to the support frame 18 receiving flow from the pump through conduit 34. A pinion (not shown) engages gear ring 36 welded to the face of reel 20. The reel cable brush contact 37 is connected to the generator inside the housing.
[0027] The housing outer wall (see Figure 3) has a console 38 with a video screen on which the operator can watch the site in front of the mobile tower by means of a camera 40 (see Figure 1) mounted thereon. There is standing room 42 on the platform for the operator. Console 38 contains controls for receiving information from sensors on the hoses which adjust reel speed to the speed of the lighting cart 14. [0028] The reel end of both hoses are attached to the reel. The opposite ends are clamped to cart 14 which is accommodated on platform 4 between the reel and the ramp 16. The hawser 44 ensures the cart 14 remains captive and prevents undue tension on the electrical cable within hose 24. The cable is rubber covered and is 40-50mm in diameter. Its sheath is 10mm thick and contains 24 wires, some of which connect the camera and cart servos to the console.
[0029] Referring now to Figure 4, the lighting cast 14 has a pair of diverging arms 48 of rectangular section which define an A-frame, the apex being supported by castor wheel 50.
[0030] The arms have a parallel portion 52 but diverge at the leading end of the cart into a horizontal extension arm 54 and a downwardly inclined shorter arm 56. Each arm bears a tyred ground wheel 58 and a raised tyred wheel 60, all the same diameter as castor wheel 50.
[0031] A 415v motor 62 is fixed to the parallel frame portion 52. A minor housing 64 adjacent the motor receives cable current, the major part of which is distributed to the lighting tower, the remainder supplying the trailer circuits and the motor 62. The motor drives a worm reduction box 66 from which a transverse drive shaft 68 extends. This rotates in journals on the straight portion 52 of the cart. Chain drive 70 turns chain wheel clusters 72 which distributes chain drive to each of the four wheels.
[0032] Two pairs of upright pivot arms 76 close to the clusters 72 provide a transverse pivot axis for a pair of inclined lighting posts 78. These are braced by rail 80 and tilt in an arc about 70-120° in response to servo jacks 82 (one shown) connected between the cart frame and the ports. The ports lie on vertical rests 84 when the trailer travels from location to location. The ports are 2.5m long so that crossbar 86 mounts a camera 40 and a desired number of floodlights, usually two pairs 88, 90, the dipping of which is selected by a servo jack 92 acting on the crossbar. The jacks 92 and console 38 receive current from a distribution circuit in minor housing 64.
[0033] In use the trailer is towed to the brink of the inclined face 100 with the ramp adjacent the slope. The engine is started, the ramp is lowered and the reel is allowed to pay out. The unit drives down the ramp at a speed which matches the reel speed. The operator uses controls at the trailer to control the ac travel motor. These controls assist in driving the travelling unit forward or backwards. The hydraulic rewinding of the drum is matched to the speed of travelling light unit via a hydraulic relief valve that opens when the reel senses load on the hose.
[0034] When the unit reaches the bottom of the slope as shown in Figure 5, the raised wheels 60 prevent the cart from tipping in the event that there is a ditch or channel 102. The unit proceeds to the brink of the next slope where the cart is stopped and the angle of the floods is adjusted.
[0035] Upon recovery the lights are tilted into the travel position and the reel retracts and the cart travels back to the ramp. The lights consume about 6000 watts varying depending on requirements. In a variant, the unit is driven by a dc motor and carries batteries which charge during daytime.
[0036] In a variant, a third servo device steers the castor wheel.
[0037] It is to be understood that the word "comprising" as used throughout the specification is to be interpreted in its inclusive form, ie. use of the word "comprising" does not exclude the addition of other elements.
[0038] It is to be understood that various modifications of and/or additions to the invention can be made without departing from the basic nature of the invention, these modifications and/or additions are therefore considered to fall within the scope of the invention.