Priority Claim

[0001 ] The present application claims priority from Australian Provisional Patent Application No. 2018902522 filed 12 July 2019 the contents of which is to be considered to be incorporated into this specification by this reference.

Technical Field

[0002] The present invention relates to a mobile track machine that has been developed principally in relation to dewatering apparatus used mining environments, in relation to the removal of water (“dewatering”) from settling ponds, tailing dams and decant ponds. It will be convenient to describe the invention in relation to that type of apparatus as used in mining environments although it is to be appreciated that the invention is not limited to that type of apparatus or to that use and can, for example be used in raw water dams, rivers and waterways amongst other applications or sites.

Background of Invention

[0003] The discussion of the background to the invention that follows is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any aspect of the discussion was part of the common general knowledge as at the priority date of the application.

[0004] Settling ponds, tailing dams and decant ponds are used in the mining industry for separating solids or immiscible liquids from water. Ponds and dams of this kind are used in mining sites where the tailings by-products of the mining processes that are entrained in water are separated in the pond or dam. The inflow of tailings into a tailings dam constantly adds water to the dam and that water can be removed for reuse in the mining operation. Liquid removal systems are thus used for that purpose. Likewise, the agriculture industry employs dams for holding water for irrigation or relies on rivers for watering stock and removal of that water from dams and rivers is required when the water is to be used. [0005] Dewatering apparatus used in the mining industry often employs a skid mounted pump assembly, comprising a pump and a motor or engine to drive the pump. The pump connects to one end of a pipe or conduit and in use, the opposite end of the pipe or conduit is disposed in a body of water from which the water is to be pumped or removed. The end of the pipe or conduit that is disposed in the body of water can be positioned in the body of water in any suitable manner that facilitates entry of water under suction into the pipe or conduit. Applicant’s International Patent Application PCT/AU2017/050697 discloses one assembly that can be attached to the end of a pipe or conduit for the extraction of water from a body of water.

[0006] The skid mounted pump assemblies known to the applicant are extremely heavy, ranging between 5 to 30 tonne or higher, depending on pump capacity.

Higher pump capacity requires higher motor capacity and so an increase in pump capacity naturally increases the weight of the pump assembly.

[0007] Pump assemblies used in mining environments are often mounted on skids so that the assemblies can be manipulated by pushing and pulling in order to locate the assemblies close to a body of water. Manipulation is usually by cranes, bulldozers or telehandlers. For greater distances of movement, the pump assemblies can be dragged onto a heavy wheeled vehicle and then transported as required.

[0008] Manipulation of skid mounted pump assemblies can be difficult. Often the ground on which a pump assembly is to be located is soft or significantly inclined.

This often means that the area in which the pump assembly is to be located needs to be graded to provide a level working surface. This is because pumps of a pump assembly work most efficiently when the pumps are level as do diesel engines that are often used to power the pumps. Moreover, because access to the area in which the pump assembly is to be located is often soft, uneven or inclined, there is often the requirement for a rudimentary roadway to be created first before access to the area can be made by the cranes, bulldozers, telehandlers or heavy wheeled vehicles used to manipulate the skid mounted pump assemblies.

[0009] Personnel safety is also an issue with the current skid mounted pump assemblies. Personnel are often required to go on to soft soil near water (tailings dams for example) sometimes containing cyanide and poisonous chemicals, with cranes and telehandlers and loaders to position skid mounted pumps.

[0010] Applicant has proposed a mobile dewatering apparatus in Australian Patent Application 2016253645 in which the apparatus is a track mounted apparatus. This provides benefits discussed in Application 2016253645, including the capability of traversing soft and/or difficult terrain, including inclines and/or slippery conditions. The present invention also relates to apparatus that includes tracks and that is relevant to dewatering apparatus, but which is distinctly different to the apparatus disclosed in Application 2016253645.

[0011 ] While the track mounted dewatering apparatus of Application 2016253645 provides the benefits discussed above, Applicant has nevertheless continued to develop the track mounted style of apparatus of Application 2016253645 in order to continually improve the track mounted offering. The present invention is intended to provide one or more improvements, or at least to offer alternatives.

Summary of Invention

[0012] According to the present invention there is provided a mobile track machine comprising: a platform for removably supporting a pump assembly, the platform having a front and a rear and a pair of spaced apart sides that extend between the front and the rear, track assemblies on each side of the platform for propelling the mobile track machine.

[0013] The present invention also provides a mobile track machine comprising: a platform, a pump assembly removably supported on the platform, the platform having a front and a rear and a pair of spaced apart sides that extend between the front and the rear, track assemblies on each side of the platform for propelling the mobile track machine, the pump assembly having a suction inlet and a discharge outlet, a pipe cutter being connected to the discharge outlet, the pipe cutter being arranged for receiving an end of a discharge pipe so that the pipe cutter can cut through the discharge pipe to sever the discharge pipe.

[0014] The present invention also provides a pumping installation having: a mobile track machine comprising: a platform, a pump assembly removably supported on the platform, the platform having a front and a rear and a pair of spaced apart sides that extend between the front and the rear, track assemblies on each side of the platform for propelling the mobile track machine the pump assembly having a suction inlet and a discharge outlet, a pipe cutter being connected to the discharge outlet, one end of a discharge pipe being connected to the pipe cutter so that the pipe cutter can cut through the discharge pipe to sever the discharge pipe.

[0015] A mobile track machine according to the invention differs from the mobile dewatering apparatus disclosed in Australian Patent Application 2016253645 because the mobile track machine of the invention is not an integral part of an overall dewatering apparatus. That is, in the invention, the mobile track machine is separate from a pump assembly, so that a selected pump assembly can be mounted or loaded onto the mobile track machine and later removed and replaced as required. This can provide significant benefits in the mining industry, given that a single track machine can be used for supporting and transporting multiple different pump assemblies depending on the specific requirements. [0016] A mobile track machine according to the invention has an instant benefit in that it can transform a skid mounted pump assembly into a track mounted pump assembly, simply by loading the skid mounted pump assembly onto the platform of the mobile track machine. Suitable arrangements can be made to secure the pump assembly to the track machine, but this can be by way of chain, tie-downs, or more customised fittings as suitable. In mining operations in which there are always some pump assemblies that are not in use, for example where pump assemblies are sent for scheduled maintenance periodically, or where some pump assemblies of certain capacity are not used very often, the invention provides advantages in that the expense of a track machine for every pump assembly is not required given that the track machines are not an integral part of the pump assemblies and so pump assemblies can be loaded and off-loaded from a single track machine as required.

[0017] A mobile track machine according to the invention can also increase the efficiency of locating a pump assembly in an operational position. For example, a pump assembly and a mobile track machine according to the invention can be transported separately to a location near where the pump assembly is to operate and at that point, the pump assembly can be loaded onto the track machine for the final section of travel to locate the pump assembly operationally. The initial travel could, for example, be by heavy wheeled vehicle so as to maximise the speed of the initial travel, as compared to transporting the pump assembly for the full travel distance on the slower moving mobile track machine. The mobile track machine can thus be used only for the final section of travel, or for any section of travel in which the wheeled vehicle is unsafe or unstable. Remote control of the mobile track machine can also increase safety in more difficult terrain locations.

[0018] Where a pump assembly is required to be craned into position, the mobile track machine according to the invention beneficially allows the weight to be lifted by the crane to be reduced compared to a pump assembly having an integral track structure. The track machine can be moved into position for receipt of the pump assembly and thereafter can it be moved to locate the pump assembly operationally. Where a pump assembly breaks down or needs to otherwise be replaced, the pump assembly can be lifted or dragged from the track machine without the weight of the track machine adding to the difficulty of that removal. [0019] Still further, where a track machine breaks down or requires scheduled maintenance, a pump assembly located on the track machine can be moved onto a new track machine rather than the combined pump assembly and track machine having to both be removed for the track machine to be worked on.

[0020] The platform of a mobile track machine according to the invention can have any suitable form. In one form, the platform comprises a flat supporting surface, such as a deck, on which a pump assembly can be supported. Side walls or lips can be upstanding at the sides of the platform to assist to locate and confine the pump assembly on the supporting surface. Likewise, end wall or lips can be upstanding at opposite ends of the platform for the same purpose. The walls or lips can form a continuous barrier about the periphery of the platform. One or more of the walls or lips can be removable or pivotable for assisting placement of a pump assembly on the supporting surface such as to allow a pump assembly to be dragged onto the supporting surface without impediment from the walls or lips, although in the present invention, the lips are of a low height (about 100mm upstanding from the supporting surface) and they are all fixed and not removable or pivotable. The upstanding lips also form a containment area for diesel or oil spillages.

[0021 ] The platform can support other components relevant to the use to which it is to be put. The platform can support a drive arrangement for driving the track assemblies. This can, for example, be a hydraulic drive arrangement. The platform can also support a fuel tank for fuelling the drive arrangement and/or the pump assembly that is supported on the platform.

[0022] In some forms of the invention, the platform removably supports a drive arrangement and/or a fuel tank. For example, the mobile track machine of the invention can removably support a drive arrangement for driving the track machine and once the track machine has been appropriately located, the drive arrangement can be removed (by crane for example) and can be replaced by a fuel tank. This arrangement has advantages for installations in which the pump assembly is to remain in one place for an extended period of time, because for that type of installation, the drive arrangement will not be required for the duration of the installation, but the addition of a fuel tank, which would be in addition to the normal fuel tank of the pump assembly, means that the mobile track machine can have significantly increased fuel capacity, so that the pump assembly will have significantly extended operation before refuelling is required. In some forms of the invention developed to date, the fuel capacity has been increased to 8,000 liters as compared to prior art capacity of around 1000 - 2500 litres without the additional fuel tank.

Moreover, a removable fuel tank means that an empty fuel tank can be replaced with a replacement full fuel tank without the need for the empty tank to be refuelled on site.

[0023] The above arrangement has further advantages by the ready replacement of a drive arrangement or fuel tank when either requires maintenance or repair. A punctured fuel tank can be removed and replaced and thereafter repaired remotely. This advantageously means that the entire mobile track machine is not required to be repatriated for repair, but rather, only the fuel tank.

[0024] The platform can support components on the supporting surface or at any other suitable position. In some forms of the invention, a drive arrangement or fuel tank can be supported at the front of the platform while in other forms of the invention, a drive arrangement or fuel tank can be supported at the rear of the platform. The support can be removable support.

[0025] The support of a fuel tank on the platform distinguishes the present invention from some existing skid mounted pump assemblies in which the fuel tank is formed as an integral part of the skid, typically within the sides of the skid. The sides are thus formed hollow for receipt of fuel. This requires the skid to have a greater height than otherwise and means that the pump assembly is at a higher position relative to the ground surface on which it is supported and so the available suction lift is reduced. The fuel tanks of these existing skid mounted pump assemblies are also more prone to puncture or cracking from the skids being dragged across rocky and uneven ground.

[0026] The support of a fuel tank on the platform also allows the capacity of the fuel tank to be increased with the benefit of reduced requirement for refuelling.

[0027] The track assemblies can be attached to the platform in any suitable manner. For example, the track assemblies can be attached to each side of the platform or they can be attached to an undercarriage of the platform, or to an underneath surface of the platform. The track assemblies can have removable tracks so that the tracks can be replaced for maintenance or repair, or to change the type of the tracks (wider tracks can be employed in soft or boggy ground), or to facilitate easier transportation (the mobile track machine is easier to transport if it can be broken down into components to fit onto a float or into a shipping container).

[0028] The track assemblies can also be movable relative to the platform so that there can be a relative lifting and lowering of the platform relative to the track assemblies. Two outcomes of this arrangement are that firstly, the platform can be lowered relative to the track assemblies to rest on the ground and the track

assemblies can be raised or lifted away from the ground, supported by the lowered platform, for easier maintenance or repair - track removal and replacement for example, and that secondly, the platform can be lifted during travel relative to the track assemblies to provide improved ground clearance and can be lowered when in position so that a pump assembly mounted on the platform can also be lowered to improve or maximise the available suction lift. The track assemblies can also be moved independently of each other for levelling purposes.

[0029] The ability to lower the platform relative to the track assemblies is a significant benefit provided by the present invention. When a prior art skid mounted pump assembly is placed in position, up to about 1 m of suction can be lost by the elevated position of the pump assembly on the skid. This can reduce significantly the suction available to remove water from the body of water, because the available suction lift is essentially dictated by the difference between the water body surface level and the pump inlet. The greater the distance, the less available suction.

[0030] In this respect, the available suction relates to the Net Positive Suction Head (NPSH), which, relative to the present invention, represents the difference between the pressure head at a particular point in the system and the vapour pressure of water. When the NPSH falls to zero the water will vapourise, creating cavitation, which can cause severe damage in pump and pipework systems. The maximum theoretical vertical distance between the water body level and the pump inlet for suction pumping of water is about 10m. At the 10m point, the water will start to vapourise. But the 10m value is only theoretical and in practice is less that that due to losses in the pumping system, friction for example. [0031 ] The Net Positive Suction Head Available (NPSHA) represents the NPSH available at the pump suction (inlet). NPSHA is a function of the suction lift (the height of the pump suction above the surface of the water body that the pump is drawing from), and the friction losses in the suction pipework. NPSHA decreases with increasing flow rate, due to the increasing friction losses in the suction pipework.

[0032] The Net Positive Suction Head Required (NPSHR) is the NPSH required at the pump suction to ensure that the pump will not experience cavitation (and the associated potentially severe damage) in operation. The NPSHR is determined by the pump design, and NPSHR invariably increases with increasing flow rate.

[0033] Pumps must be deployed and operated in a manner that ensures that the NPSHA is greater than the NPSHR. In many deployments, the maximum permissible operating flow rate is the flow rate at which the NPSHA is equal to NPSHR.

[0034] Importantly, with respect to the present invention, lowering the platform on which the pump assembly is supported will increase the maximum permissible flow rate. This occurs because lowering the platform will increase the NPSHA (by reducing the suction lift). In NPSH limited systems, this will increase the maximum permissible flow rate for a particular location.

[0035] The improvement achieved by lowering the platform is dependent on the flow rates, suction lift, and the characteristics of the pump and pipework system, but a 1 metre reduction in suction lift can be expected to deliver an increase in maximum permissible flow which is significant.

[0036] For example, dropping the pump inlet from a height of 3m to 2m, for some pumps could increase flow rate by 15%. Dropping the pump inlet from a height 4m to 3m could increase the flow rate by 10%. These numbers will change with different pumps. Effectively, if you are NPSH limited, dropping the level of the pump inlet will increase the maximum volume flow rate when the NPSH is limited. There can be situations when the pump is not initially NPSH limited, but as the level of the waterbody drops, NPSH limited will eventually be achieved.

[0037] The ability to lower the platform relative to the track assemblies can improve the flexibility in where a pump assembly is deployed. With any pump assembly, as a water body is drawn down, the suction lift will increase and the

NPSHA will decrease. For a given flow rate, this will eventually cause the NPSHA to fall to match the NPSHR, at which point the pump assembly will need to be moved to lower elevations to reduce the suction lift and so permit further pump operation.

However, the ability to lower the platform of a mobile track machine according to the invention will enable the water body to be drawn down further before this limiting condition is reached in a given deployment position, thus reducing the frequency with which the pump assembly must be moved. This provides clear benefits to the operator.

[0038] Still further, the ability to lower the platform will also facilitate positioning of the pump assembly further from the edge of the body of water and/or at higher elevations, which is a distinct advantage for operations at locations with difficult (steep or slippery) bank conditions.

[0039] It follows that the ability to lower the platform once the mobile track machine is deployed provides clear and significant advantages over skid mounted pump assemblies.

[0040] The track assemblies can be movable relative to the platform in any suitable manner. In some forms of the invention, a lifting facility is disposed between the platform and each of the track assemblies to lift or lower the platform relative to each of the track assemblies. The lifting facility can comprise a single lifting unit disposed between each of the track assemblies and the platform, or a pair of lifting units can be disposed between each of the track assemblies and the platform, for example, at or towards opposite ends of the respective platform and track

assemblies.

[0041 ] In one form envisaged currently, the track assemblies on either side of the platform are connected to the platform by a lifting facility that includes lifting units in the form of rotatable legs that connect to crank shaft assemblies. A bottom end of the legs rotatably connects to the track assemblies and a top end of the legs is fixed to a respective crank shaft of a crank shaft assembly for rotation with the crank shaft. When a crank shaft is driven to rotate, the leg attached to the crank shaft also rotates, tending to either raise or lower the platform relative to a track assembly depending on the direction of rotation of the crank shaft. The movement of the platform relative to the track assemblies is thus arcuate, so that not only does the platform move up and down relative to the track assemblies, there is also some back and forward

movement.

[0042] A single crank shaft can extend across the platform to engage with a pair of rotatable legs at opposite sides of the platform. Alternatively, two separate crank shafts can be employed on each side of the platform. The earlier arrangement will mean that the respective rotatable legs will rotate together and to the same amount, whereas the latter arrangement will mean that the rotatable legs on opposite sides of the platform can be rotated independently of each other, so that the track assembly on one side of the platform can be raised or lowered independently of the track assembly on the other side of the platform. Moreover, crank shafts can be positioned at each of the front and rear ends of the track machine and so that either the front of the platform can be raised or lowered independently of the rear the platform, or the front and rear ends of the platform can be raised and lowered together and to the same amount.

[0043] The crank shaft assemblies can be driven in any suitable manner. For example, the crank shafts can include a crank arm or arms to be driven by a hydraulic or pneumatic actuating cylinder to rotate the crank shaft. The actuating cylinder can directly engage the crank arm. Where first and second crank shafts are employed at the front and rear ends of the platform on each side of the platform, the actuating cylinder can directly engage the crank arm of the first crank shaft, while a push bar can connect between the crank arms of the first and second crank shafts, so that drive of the crank arm of the first crank shaft by the actuating cylinder causes the push bar to drive the crank arm of the second crank shaft. This arrangement advantageously ensures that both of the crank shafts rotate when the actuating cylinder is actuated and despite that the actuating cylinder only connects to one of the crank shafts.

[0044] Alternatively, a separate actuating cylinder can drive the crank arms of the respective of the first and second crank shafts. Alternative drive arrangements include a linear motor or a drive screw, or a chain drive. However, an hydraulic actuating cylinder is preferred given that hydraulic power on a track machine would normally be provided.

[0045] The above described arrangements advantageously permits the platform to be raised during travel of the track machine and to be lowered when the track machine has reached an operational pumping location. Lowering of the platform is optional and might not be employed at every opportunity, particularly where adequate suction lift is available without the platform being lowered.

[0046] The above described arrangement also advantageously permits the track assemblies on one side of the track machine to be raised and lowered independently of the track assemblies on the other side of the track machine, so that side to side levelling of the track machine can be made by independently adjusting the position of the respective track assemblies relative to the platform. Thus, the mobile track machine according to the invention can include a levelling arrangement. The levelling arrangement can also include jacking legs that are applied about the periphery of the platform (such as at or near the corners of a rectangular platform) so that the platform can be levelled when it is positioned on sloping or uneven ground. The jacking legs can be independently adjustable.

[0047] The mobile track machine according to the invention can also include a blade at the front of the machine for the purpose of grading and cutting roads or paths for location of the track machine, or for shifting detritus, such as tree growth or rocks or boulders, that may form an impediment to the forward travel of the track machine. As indicated above, there is often the requirement for a rudimentary roadway to be created before access to the pumping location can be made and despite that the track machine of the invention is expected to have significantly greater mobility than prior art skid mounted track machines, the provision of a blade at the front of the track machine is considered to be a useful addition where the ground conditions that the track machine faces are testing for the track machine despite the improved ability of the track machine to handle more difficult terrain.

[0048] The mobile track machine according to the invention can also include a pipe or hose cutter for severing the pipe at the discharge outlet of the pump assembly. The discharge pipe of the pump assembly will extend through the pipe cutter and the pipe cutter includes a blade that can be forced through the pipe to sever the pipe. Absent an emergency, the discharge pipe would ordinarily be disconnected manually by personnel unbolting the discharge pipe from the discharge outlet of the pump assembly. This can take several hours, if it can be done at all because often the pump assembly is located close to the water’s edge and personnel cannot be safely sent to the water’s edge to unbolt the discharge line. When the pump assembly is skid mounted, it cannot therefore be moved and may become submerged, causing it to be damaged or lost altogether. If the pump assembly is mounted on a track machine, the same issue may arise in that the track machine might not be movable if the discharge pipe cannot be disconnected.

[0049] The pipe cutter will be used in emergencies when there has been a failure or an event that requires the track machine to be evacuated from the pumping location. The pipe cutter would not typically be used other than in emergencies In such an emergency or event, continued connection of the discharge pipe to the pump assembly will make the evacuation of the track machine either very difficult or even impossible. This is because without the discharge pipe being severed from the pump assembly, the track machine will need to push the discharge pipe in the direction of evacuation (usually uphill) for the track machine to be moved. However, the discharge pipe would normally be full of water and the weight of the discharge pipe can be in the order of 111. The track machine is unlikely to be able to push that weight.

[0050] Accordingly, a pipe cutter can advantageously facilitate disconnection of the discharge pipe from the pump assembly so freeing the track machine to evacuate from the pumping location.

[0051 ] While a pipe cutter can be used as described above, a consequence of the use of the pipe cutter when the discharge pipe is full, is that the contents of the discharge pipe will immediately start to flow out of the severed and open end of the discharge pipe, meaning that in order of 111 of water can start to gush out of the discharge pipe uncontrolled. This can be extremely dangerous for any personnel in the immediate vicinity of the severed end. The discharging water can potentially flood the pumping location or can present a slipping or wash away hazard, while the water being discharged can be toxic. Moreover the end of the discharge pipe can whip around dangerously. It follows that if water in the discharge pipe is to be allowed to gush out of the severed end uncontrolled, then personnel should not be in the vicinity of the track machine and the invention caters for this by the track machine being remote controlled. The remote control can be used to actuate the pipe cutter and to thereafter retrieve the track machine from the pumping location to safety.

[0052] It is to be noted that the continued connection of the suction pipe does not impose the same impediment to the evacuation of the track machine from the pumping location as the discharge pipe. The suction pipe will start drain itself as soon as suction pressure is terminated and so the track machine will only usually need to drag the weight of the suction pipe itself and not a body of water within the suction pipe, as compared to pushing the weight of a full discharge pipe. It is expected that the track machine of the invention can adequately evacuate with the suction pipe still connected to the suction inlet of the pump assembly, although in a further form of the invention, a pipe cutter, such as a remote controlled pipe cutter, can be applied to the suction pipe as well.

[0053] While the remote control of the track machine can provide safety against the injury to operational personnel, the uncontrolled discharge of water from the severed end of the discharge pipe can still be dangerous to the track machine, if the end of the discharge pipe does whip around into engagement with components of the track machine, or if the discharging water floods the pumping location, thus flooding the track machine also. For this reason, the discharge pipe can include a one-way or non-return valve upstream of the discharge outlet of the pump assembly and the pipe cutter, which automatically closes upon reverse flow of water within the discharge pipe back towards the track machine, so terminating flow of water to and out of the severed end of the discharge pipe. The non-return valve can be positioned relatively close to the discharge outlet of the pump assembly so that the amount of water that does gush out of the discharge pipe is minimised.

[0054] The use of a non-return valve provides the advantages discussed above, but one downside is that once shut, the non-return valve bears the load of water upstream of the valve, which as indicated above, can be in the order of about 111 (although it will be less than this given that the non-return valve will not normally be positioned at the discharge outlet of the pump assembly). Accordingly, a small diameter bypass pipe can connect upstream and downstream sides of the non-return valve. The diameter of the bypass pipe is smaller than the diameter of the discharge pipe and is preferably at least 25% smaller. The bypass pipe will allow a much reduced amount of water to continue to flow from the upstream side of the non-return valve to the downstream side, so that pressure on the upstream side of the non-return valve progressively reduces as water within the discharge pipe flows through the bypass pipe and out of the severed end.

[0055] A major advantage of the above arrangement is that without the bypass pipe, the upstream side of the non-return valve is exposed to the full water pressure of the water that remains in the discharge pipe once the non-return valve has activated. That presents a problem when the emergency failure or event is over and the non-return valve needs to be opened or reset. With potentially about 111 of water bearing down on the upside of the valve, ordinarily, it would be necessary to cut or drill a hole in the non-return valve or to insert a tap, in order to drain the upstream water. But by employing the bypass pipe, the upstream water will have already been drained, at a slow and safe flow rate, or at least the upstream pressure will have already been reduced by at least some of the upstream water having been drained, so that the non-return valve can be reset in the normal manner.

[0056] The bypass pipe can also prevent water hammer that can occur upon sudden closure of a non-return valve, allowing some reduced but continuing flow of water within the discharge pipe and thus reducing the rate of deceleration of the water upon closure. The bypass pipe can also assist where a second non-return valve is placed closer to the pump assembly. Where two non-return valves suddenly shut down together a pressure wave can be created reverberating between the respective valves, which can cause a rhythmic opening and closing of the valves. The bypass pipe provides a path by which that wave can pass through the valves and continue downstream, interrupting the reverberation and mitigating the effect.

Brief Description of Drawings

[0057] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which: [0058] Figure 1 illustrates an exploded view of a mobile track machine according to one embodiment of the invention and a pump assembly to be mounted on to the track machine.

[0059] Figure 2 illustrates an assembled view of the arrangement of Figure 1.

[0060] Figure 3 illustrates an insitu arrangement of a track machine according to the invention.

[0061 ] Figure 4 pipe cutter for use with the present invention.

[0062] Figure 5 is a cross-sectional view of the of the pipe cutter of Figure 4.

[0063] Figure 6 illustrates a non-return valve for use with the present invention.

[0064] Figure 7 is a cross-sectional view of the non-return valve of Figure 6.

[0065] Figure 8 shows a further track machine according to the invention.

[0066] Figure 8a shows the lifting facility of Figure 8 in isolation.

[0067] Figures 9 to 11 show the sequence of movement of the track assembly from a lowered position to a raised position.

[0068] Figure 12 illustrates a perspective view of the track machine of Figure 8.

[0069] Figure 13 illustrates an end view of the track machine of Figure 8.

Detailed Description

[0070] Figure 1 illustrates an exploded view of a mobile track machine 10 and a pump assembly 11 according to one embodiment of the present invention. The pump assembly 11 is shown elevated above the track machine 10 and from the description that follows, it will be evident that the pump assembly 11 is to be loaded on to the track machine 10 and supported by the track machine 10.

[0071 ] Figure 1 thus shows a mobile track machine 10 for supporting a pump assembly 11. The pump assembly 11 is shown mounted on a skid 12 and it is appropriate for either the entire pump assembly 11 including the skid 12 to be mounted on the track machine 10, or for the skid 12 to be removed from the pump assembly 11 prior to mounting the assembly 11 onto the track machine 10. The preference is that the skid 12 is removed, as that lowers the overall height of the pump assembly 11 , which is beneficial for maximising the suction lift that the pump assembly 11 can provide.

[0072] The pump assembly 11 illustrated includes a pump and a motor to drive the pump. Other additional componentry is provided as is required for connecting the motor and the pump and for connecting a conduit to the pump. The pump assembly 11 illustrated is in a form that is currently used in mining environments and by mounting the assembly 11 on a skid 12 enables the assembly to be dragged and pushed by cranes, bulldozers or telehandlers .

[0073] The track machine 10 includes a platform 13 on which the pump assembly 11 can be mounted. The platform 13 is a flat deck and is formed to have a generally rectangular shape. The shape of the platform 13 is dependent on the footprint of the pump assembly 11.

[0074] The platform has a front and rear, 15 and 16, and spaced apart sides 17. Upstanding walls or lips 18 to 20 extend at the respective front, rear and sides of the platform to form a barrier about the platform. The pump assembly 11 is therefore loaded into an area bounded by the platform 13 and the lips 18 to 20. The front lip 18 can be formed to connect pivotally to the platform 13, so that the pump assembly 11 could be dragged on to and off the platform 13 through the front end 15.

[0075] Track assemblies 22 and 23 are attached to the sides 17 of the track machine 10 by connection arrangements 24 (which can only be seen on one side of the machine 10). These connection arrangements 24 can facilitate lifting of the track assemblies 22 and 23 relative to the platform 13 for the purpose of either lowering the platform 13, or raising the track assemblies 22 and 23. Alternatively, the connection arrangements 24 can fix the track assemblies at one height relative to the platform 13.

[0076] A drive arrangement or fuel tank 25/26 is supported at the rear end 15 of the track machine 10 on supports 27 that are fixed to the rear end 15 and in Figure 1 , it is the drive arrangement 25 that is shown fixed in place on the rear end 15 of the track machine 10. The drive arrangement 25 is removably attached to the supports 27 by bolting and can be replaced by the fuel tank 26 as required. [0077] As discussed above, the track machine 10 can removably support the drive arrangement 25 for driving the track machine 10 as required to operationally position the pump assembly 11 and once the track machine has been appropriately located, the drive arrangement 25 can be removed (by crane for example) and can be replaced by the fuel tank 26. This is a relatively easy operation and has significant benefits if the pump assembly 11 is to remain in one place for an extended period of time. Moreover, as discussed above, a removable fuel tank means that an empty fuel tank can be replaced with a full fuel tank without the need for the empty tank to be refuelled on site.

[0078] Jacking legs 28 and 29 are shown fixed to the front corners of the platform 13. The jacking legs 28 and 29 can equally be connected to different parts of the track machine 10 and still operate effectively. The jacking legs 28 and 29 for example, can be connected underneath the platform 13, or to outer and facing surfaces of the front lip 18 or the side lips 20. The jacking legs 28 and 29 can be manually operable such as by manual hydraulic operation or by screw thread operation, or they can be driven via engines or motors provided in the pump assembly 11 , or in the drive arrangement 25. Further jacking legs can be provided at the rear corners of the platform 13, so that four points of jacking can be provided.

[0079] A pipe or hose cutter 35 is provided for cutting the discharge pipe or hose in an emergency for the reasons discuss earlier herein.

[0080] In an emergency, the use of a track machine according to the invention also facilitates withdrawal and subsequent preservation of the entire track machine and pump assembly as compared to a skid mounted pump, as the skid mounted pump would require a crane, bulldozer or telehandler to be brought in for withdrawal, whereas the track machine can simply be driven away as soon as the emergency arises (and as soon as the pipe or hose is cut if required). This potentially means that the track machine form of the invention will be saved in an emergency whereas the skid mounted pump could be lost. In addition, in some forms of the invention, the drive of the track machine will be remote, so that mining personnel are not required to go to the emergency site. [0081 ] At the front end 15, a hose connection frame 40 is provided. The frame 40 has an opening 41 through which a hose can extend in a close fit and the arrangement is such as to maintain alignment of the hose with the pump assembly 11 at all times, rather than allowing the hose to become angled to the pump assembly 11 which can potentially damage the pump or the connection with the hose. In this respect, when the pump assembly 11 is operating with a hose extending from the assembly to a body of water, the hose can drift, such as under the influence of wind or current, and can place load on the connection of the hose to the pump assembly. Also, the invention allows a hose to be pushed into a body of water by driving the track machine 10 towards the body of water. The track machine 10 and the pump assembly 11 thus push the hose forwards and the hose acts like a column. This can even be done with attachments made at the inlet end of the hose remote from the pump assembly 11. Such attachments can include intake assemblies such as disclosed in the Applicant’s International Patent Application PCT/AU2017/050697.

[0082] However, if, in pushing the hose towards the body of water, the hose moves offline or buckles, load can be placed on the hose connection with the pump assembly 11. However, in the present invention, the connection frame 40 will take the load and not the pump assembly 11. The connection frame 40 thus takes the load and structurally supports it by dispersing the load back into the track machine 10. This differs from skid mounted pump assemblies, in that whenever the pump assembly is moved, the hose has to be disconnected. The invention thus saves time.

[0083] Figure 1 shows the pump assembly 11 in the form that is used in mining environments for dewatering applications. The track machine 10 could obviously be used to support and transport other forms of pump assemblies and indeed other components.

[0084] Figure 3 illustrates an insitu arrangement of a track machine according to the invention, taken from side on. The track machine 50 of figure 3 is very similar to the track machine 10 of figures 1 and 2, but further includes a blade 51 at the front of the track machine 50 which can be used for grading and cutting roads or paths, or as shown, can be used to lift the forward end of the track machine for leveling purposes. In this respect, the blade 51 is connected to a hydraulic strut 52, which can lift the front end of the track machine 50 as the blade 51 is lowered so that as shown, the front end of the track assembly 52 is raised above the ground surface 53 in order for the track machine 50 to be leveled horizontally. That leveling operation can be completed equally with jacking legs as shown in figures 1 and 2, but figure 3 illustrates the alternative arrangement.

[0085] Figure 3 thus shows a sloping ground surface 53 on which the track machine 50 is disposed. A liquid intake 55 is shown floating on a body of water 56 and the intake 55 that is illustrated is as described in applicant’s international PCT patent application (WO 2019 /119064).

[0086] A suction hose 57 extends between the intake 55 and the suction inlet of the pump assembly 58. The suction hose 57 extends through a hose connection frame 59, which is essentially equivalent to the connection frame 40 of the earlier figures while a float 60 is disposed midway along the suction hose 57 for buoyancy purposes.

[0087] The arrangement of figure 3 also illustrates a discharge pipe 65 that connects to the discharge outlet 66 of the pump assembly 58. The discharge pipe 65 extends through a pipe cutter 67 for severing the discharge pipe 65 in emergency situations and the discharge pipes 65 extends to a non-return valve 68 and thereafter onto a water storage or treatment facility or other facility to which water from the body 56 is to be pumped.

[0088] The pipe cutter 67 is provided for severing the discharge pipe 65 during emergency events or situations, for the reasons as detailed earlier herein. Once the discharge pipe 65 is severed at the pipe cutter 67, the track machine 50 can be driven either manually or remotely, depending on the drive arrangements provided, up the ground surface 53 and away from the body of water 56. There are various reasons why it might be necessary to shift the track machine 50 upwardly along the body of water 56, but one reason is where the water level of the body 56 rises to the point at which is starts to flood the track machine.

[0089] Figures 4 and 5 show detail of the pipe cutter 67 and with reference to figure 4, a portion of the discharge outlet 66 is shown coupled by the coupling 69 to an inlet section of the discharge pipe 65. Once assembled, the discharge pipe 65 would extend through the sleeve 70 and extend out of the opposite side of the pipe cutter 67. Figure 5 illustrates the assembled configuration and also shows the blade 71 of the pipe cutter 67 having been pushed through the upper surface of the discharge pipe 65. The blade 71 is driven by a piston 72 under an hydraulic load, and eventually passes completely through the discharge pipe 65 and into a channel 73. It can be seen that the discharge pipe 65 is a loose fit within the sleeve 70, so that once the blade 71 has passed through the discharge pipe 65, the severed end of the discharge pipe 65 is free to be released from the pipe cutter 67. Once released, it will be apparent that any water held within the discharge pipe 65 upstream of the pipe cutter 67 is free to discharge out of the pipe 65.

[0090] The piper cutter 67 can be operated remotely and quickly in an emergency situation. Once the pipe cutter 67 had been actuated so that the discharge pipe 65 has been severed, the track machine is free to move away from the body of water 56 unhindered by connection to the discharge pipe 65. If the severed end of the discharge pipe 65 does not automatically release from within the sleeve 70, then a slight downward movement of the track machine 50 can be initiated and once the pipe 65 has released from within the sleeve 70, the track machine 50 can thereafter be driven up the ground surface 53 and away from the body of water 56, either manually or remotely.

[0091 ] As indicated above, movement of the track machine 50 up the ground surface 53 can take place with the suction pipe 57 still connected to the pump assembly 58, as any water held within the suction pipe 57 will naturally drain out of the pipe 57 once suction pressure is released.

[0092] As explained above, if the discharge pipe 65 is severed by the pipe cutter 67, without the inclusion of the non-return valve 68, all of the water within the discharge pipe 65 will gush out of the pipe 65 at the severed end. Given that this can be dangerous to both personnel that might be in the vicinity of the track machine 50, or to the track machine 50 itself, the non-return valve 68 is provided. The non-return valve 68 has a unique construction as hereinafter described.

[0093] The non-return valve 68 is shown is side view in figure 6 and in cross sectional perspective view in figure 7. Opposite ends 75 and 76 connect to sections of the discharge pipe 65, while a central section 77 houses a non-return flap assembly 78 that comprises a pair of flaps 79.

[0094] The flaps 79 assume an open position when flow through the non-return valve 68 is away from the discharge outlet 66. However, when flow reverses, such as when the pipe cutter 67 severs the discharge pipe 65, the flaps close by rotating outwardly to form a barrier within the central section 77. Advantageously, this means that flow through the section of the discharge pipe 65 between the non-return valves 68 and the severed end terminates, thus preventing water from gushing out of the severed end and presenting a safety issue for personnel within the vicinity, or for the track machine 50. However, as explained earlier herein, once the emergency event has resolved itself and it is desired to open the non-return valve 68, water pressure bearing against the flap assembly 78 makes opening of the non-return valve 68 very difficult. As explained above, there can be 111 of water bearing against the flap assembly 78.

[0095] Accordingly, the applicant has developed a bypass arrangement, whereby a bypass pipe 85 is in fluid communication with the interior of the valve 68 on opposite sides of the valve assembly 78. Thus, if the discharge pipe 65 is severed by the pipe cutter 67, the flap assembly 78 will automatically actuate and close flow through the non-return valve 68, but a significantly reduced flow can still take place though the much smaller diameter bypass pipe 85 as shown by the arrows in Figure 6. The three arrows on the upstream side represent the much greater water load on that side of the valve assembly 78. The single arrow that exits the downstream side is not indicating that 1/3 of the flow goes through the bypass pipe 85, but rather, that a significantly reduced flow takes place. This allows water to drain out of the discharge pipe upstream of the valve 68 but in a slow and controlled manner so that eventually, there is no pressure bearing against the flap assembly 78 and so that it can be opened in the normal manner, which in some valves will be via a spring bias once the pressure load against the flap assembly 78 is removed or reduced below the spring force.

[0096] The track assembly of the present invention can also provide for relative movement between the track assemblies and the platform. In figures 1 and 2, reference is made to the connection arrangements 24 that facilitate lifting of the track assemblies 22 and 23 relative to the platform 13, but figures 8 to 13 show a different arrangement for performing the same function. In figure 8, a track machine 100 is illustrated without the inclusion of a pump assembly or other components such as a drive arrangement or fuel tank, so that the track machine 100 illustrated in figure 8 includes in transparent form, a pair of track assemblies 101 and 102, a platform 103 and a lifting facility that is disposed between the platform 103 and the track assemblies 101 , 102 which is capable of lifting or lowering the platform 103 relative to the track assemblies 101 , 102. The lifting facility is shown in isolation in Figure 8a.

[0097] The track assembly of figure 8 includes front and rear rotatable legs 104 and 105. The rotatable legs each rotatably connect to a respective assembly 101 or 102, and fixedly connect to a crank shaft 106 (see figure 8a). Each of the rotatable legs 104, 105 on each side of the platform 103 is provided with a separate or individual crank shaft 106.

[0098] Also attached to the crank shafts 106 are crank arms 107 and 108. The forward crank arms 107 are respectively driven by hydraulic struts 109. The crank arms 108 are respectively driven by push arms 110 that connect to the end of the hydraulic struts 109, so that the crank arms 108 are rotated at the same time and to the same extent as the crank arms 107 are rotated when driven by the struts 109.

[0099] The arrangement of figure 8 means that the track assembly 101 can be raised or lowered independently of the track assembly 102. This is illustrated in figure 12, in which the track assembly 101 is at a maximum lowered position, while the track assembly 102 is at a maximum raised position. Figure 13 is a view from the front end of the track assembly 100 of figure 12 and shows the raised and lowered positions of the respective track assemblies 101 and 102.

[0100] Figures 9 to 11 show the sequence of movement of the track assembly 101 from a lowered position (figure 9) to a raised position (figure 11 ).

[0101 ] In figure 9, the crank arms 107 and 108 are at an angle to horizontal and the strut 109 and the push arm 110 are coaxial.

[0102] In figure 10, the strut 109 has been retracted, also retracting the push arm 110 to bring the crank arms 107 and 108 to a vertical position, The strut 109 and the push arm 110 are now slightly off coaxial by virtue of the greater downward extension of the crank arms 107 and 108 compared to the figure 9 orientation. Moreover, the rear end 111 has moved to about alignment with the rear end 112 of the track assembly 101.

[0103] Finally, continued retraction of the strut 109 continues to withdraw the push arm 110 to bring the crank arms 107 and 108 to an angled position and back to the position in which the strut 109 and the push arm 110 are coaxial. The rear end 111 of the platform 103 now extends beyond the rear end 112 of the track assembly 101.

[0104] While the images of figures 9 to 11 are schematic, it can be seen that the upper surface of the platform 103 has been lowered an amount which is about equal to the height of the track assembly 101. In practice, this height differential can be in the order of about 1 m. For reasons already described above, this mechanism of lowering the platform allows for a significant increase in suction lift over prior art arrangements in which the platform remains at a fixed height.Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

[0105] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

[0106] Where any or all of the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.