AU1954899A - Excavation apparatus and a method of use thereof - Google Patents

Description

WO 99/35345 PCT/AU99/00010 -1 TITLE: EXCAVATION APPARATUS AND A METHOD OF USE THEREOF Field Of The Invention The present invention relates to a method and apparatus for excavation. The invention has been developed primarily for use in digging holes to access 5 sewers in areas where other services such as gas mains or electrical cables may be buried. However, it will be appreciated that the invention is not limited to this particular field of use. Background To The Invention Prior art methods for excavating holes typically involve solid digging implements 10 such as shovels which require a high degree of manual labour when excavating. Mechanically assisted excavating machines, for example bobcats, bulldozers, backhoes and loaders all use a similar basic principle to that of the humble shovel. In particular, the aforementioned mechanically assisted excavating devices utilise solid scoops of varying configurations which cut into the ground. A disadvantage shared by all of the 15 aforementioned prior art excavating devices may be experienced when excavating regions having various submerged services such as gas pipes, water mains, electrical or optical fibre cables, and the like. When the prior art excavating implements strike this type of submerged service, there is a substantial risk that the scoop will inadvertently damage or sever the service. This may result in disruptions to services which can have 20 unpredictable and potentially 'very expensive ramifications. For example, if a telecommunications optical fiber is inadvertently severed, a large number of users of the telecommunications system may be adversely affected, potentially resulting vast WO 99/35345 PCT/AU99/00010 -2 unpredictable economic loss Additionally, once damaged or ruptured, further expense will be incurred in repairing the affected service. A further disadvantage associated with the mechanically assisted excavating devices mentioned above is the substantial room required for their operation, which may 5 be a limiting factor when excavating in narrow confines. Also, the operation of mechanical excavators often causes significant noise. Disclosure Of The Invention It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. 10 According to a first aspect of the invention there is provided an excavating device including: a pressurised cutting fluid source communicating with an outlet adapted to spray cutting fluid so as to excavate material adjacent said outlet; and suction means disposed so as to suck detritus resulting from excavated material 15 away from said outlet. Preferably the cutting fluid is, or includes, water provided at a pressure of greater than 2000 psi and dispensed from the outlet at a rate of less than 200 litres per minute. More preferably the pressure exceeds 4000 psi and the flow rate is less than 25 litres per minute. 20 According to another aspect of the invention there is provided a method of excavating including the following steps: (a) providing a pressurised cutting fluid source communicating with an outlet adapted to spray cutting fluid; WO 99/35345 PCT/AU99/00010 -3 (b) spraying cutting fluid from said outlet so as to excavate material adjacent said outlet; and (c) using suction means disposed proximate said outlet to suck detritus resulting from excavated material away from said outlet. 5 Specific embodiments in accordance with the invention will now be described by way of non-limiting examples. Detailed Description Of Specific Embodiments The accompanying drawings depict the following: Figure 1 is a schematic depiction of an embodiment of an excavating device 10 according to the invention; Figure 2 is a side view of an embodiment of a nozzle according to the invention; Figure 3 is a bottom view of the nozzle shown in figure 2; Figure 4 is a side view of another embodiment of a nozzle according to the invention; 15 Figure 5 is a bottom view of the nozzle shown in figure 4; Figure 6 is a side view of yet another embodiment of a nozzle according to the invention; Figure 7 is a side view of a cutting fluid hose and a suction hose according to the invention; 20 Figure 8 is a side view of an embodiment of the invention; Figure 9 is a side view similar to that of figure 7, but also showing a camera; and Figure 10 is a perspective view of a gantry according to the invention.

WO 99/35345 PCT/AU99/00010 -4 Referring to the drawings, the excavating device 1 includes a pressurised cutting fluid source 2 communicating with an outlet 3 adapted to spray cutting fluid (not shown) so as to excavate material 4 adjacent the outlet. The device 1 also includes suction means 5 disposed so as to suck detritus (not shown) resulting from excavated material 5 away from the outlet 3. In one preferred embodiment the cutting fluid is, or includes, water and in another preferred embodiment the cutting fluid is, or includes, air. The pressure at which the cutting fluid is sprayed from the outlet 3 will vary depending upon the strength of the material being excavated. For example, when 10 excavating concrete, bitumen or rock, the required pressure will usually be greater than that for sand or soil. If the cutting fluid is water, the preferred embodiment typically utilises pressures in excess of 2000 psi. A more preferable pressure range is between 3000 psi and 40,000 psi, and a still more preferable pressure range is between 4000 psi and 20,000 psi. 15 The preferred embodiment advantageously utilises a combination of high water pressure with a low water pumping rate. This helps to minimise the total volume of water which must be sucked by the suction means 5 from the excavated hole. Additionally, it means that less water combined with detritus must be stored. In the preferred embodiment cutting fluid is ejected from the outlet 3 at a rate of less than 200 20 litres per minute. Indeed, flow rates of as low as 100, 25 or 15 litres per minute have been successfully used in secret trials.

WO 99/35345 PCT/AU99/00010 -5 The cutting fluid flows from the pressurised cutting fluid source 2 to the outlet 3 via a cutting fluid hose 6. Various nozzles 7, as shown in Figures 2, 3 and 4, are detachably disposed upon the cutting fluid hose 6 to form the outlet 3. Figures 2 and 3 show a nozzle 7 rotably disposed upon the cutting fluid hose 6 5 with an axis of rotation 8. This nozzle 7 includes a first aperture 9 which is off-set from the axis of rotation 8 and is oriented such that the ejection of a stream of cutting fluid 10 through the first aperture 9 promotes rotation of the nozzle 7. This rotation results in the stream of cutting fluid 10 forming a surface of rotation which effectively forms a cutting cone (not shown). The nozzle 7 further includes a second aperture 11 disposed opposite 10 the first aperture 9 such that the axis of rotation 8 lies substantially intermediate the first and second apertures 9 and 11. The second aperture 11 is oriented such that ejection of a stream of cutting fluid 12 through the second aperture 11 also promotes rotation of the nozzle 7. The stream of cutting fluid 12 aligns, through rotation of the nozzle 7, with the stream of cutting fluid 10 to form a single cutting cone. In other words, this nozzle 15 arrangement results in a fairly broadly dispersed cone formed from two separate streams of high pressurised water 10 and 12. Hence, this nozzle provides a cutting implement of relatively low to intermediate cutting force. It is particularly suited to excavating soft material such as sand or soil. The cutting strength of each of the nozzles generally varies inversely 20 propositionally to the distance from the outlet. Accordingly, material close to the nozzle will be subject to a stronger cutting force, whereas material distant from a nozzle will be subject to a minimal cutting force. For these reasons, the invention is well suited to excavating in regions suspected of containing submerged services as sewer pipes, WO 99/35345 PCT/AU99/00010 -6 electrical cables and the like. This is particularly true of the rotating nozzle as, at a distance of approximately 20cm away from the nozzle, the stream is strong enough to excavate soil without damaging submerged services. However it is important to ensure that the nozzle is not brought into excessively close proximity to services as the cutting 5 force may then be sufficient to damage some services. The nozzle shown in Figures 4 and 5 is better suited to applications requiring high cutting intensity. This version of the nozzle 7 does not rotate. Rather, it includes a single aperture 12 shaped to eject the cutting fluid in a narrow stream 13. This nozzle 7 is useful for cutting through hard materials such as bitumen, concrete, rock and the like. 10 Due to the high cutting intensity of the stream 13, greater care should be taken to ensure that services are not inadvertently ruptured by accidentally placing this version of the nozzle 7 too close to submerged surfaces. This version of the nozzle 7 is typically used to cut through a road surface and once the soil beneath the road surface has been exposed, the operator would detach this version of the nozzle and attach the rotating 15 version shown in Figures 2 and 3 to excavate the soil. The nozzle 7 shown in Figure 6 produces a stream 14 which diverges more than the stream 13 produced by the nozzle of Figure 4 but less than the cone produced by streams 10 and 12 of the nozzle 7 shown in Figure 2. The nozzle 7 of Figure 6 is best suited to applications where is it necessary to commence excavating at a surface 20 consisting of soil. This is because the broad cutting cone provided by the nozzle shown in figures 2 and 3 causes significant unwanted splashing of cutting fluid and detritus when commencing excavation at the surface. This splashing is minimised by the nozzle of figure 6 due to the narrower stream which it provides. The nozzle of Figure 6 also WO 99/35345 PCT/AU99/00010 -7 provides a less intense cutting stream 14 as compared to the narrow cutting stream 13 shown in Figure 4. This gives rise to a reduced likelihood that services will be inadvertently ruptured when excavating using the nozzle 7 shown in Figure 6. Referring to Figure 1, the suction means 5 includes a pump 15 which sucks 5 detritus (not shown) from the excavation site 4, along a suction hose 16 and ultimately into a storage tank 17. When using water as the cutting fluid, the storage tank 17 includes de-watering means 18 adapted to expel at least some of the water from the storage tank 17. The de-watering means 18 is in the form of a pipe disposed inside the tank 17. The pipe 18 includes a plurality of holes 19 each disposed at various heights so 10 as to capture water within the tank 17 once the detritus has settled to the bottom 20 of the storage tank 17. Once the waste water has passed through holes 19 it exits from the tank 17 via waste water exhaust 21. The pressurised fluid source 2 includes a water reservoir 22 and a pump 23 which acts upon the water from the reservoir 22 to raise it to the required pressure. In some 15 embodiments a single pump is adapted to both provide the raised water pressure required for the pressure cutting fluid source 2 and the vacuum required for the suction means 5. The console 25 includes a plurality of controls 26 to enable an operator (not shown) to remotely control the operation of the excavating device 1. One of the controls 26 is a fluid actuator which opens or closes a valve 27 in the hose 6 to start and/or stop 20 the flow of cutting fluid through the outlet 3. Another of the controls 26 is operable to adjust the suction provided by the suction means 5. A plurality of extension pipes 28 are optionally attachable to the cutting fluid hose 6 between the console 25 and the outlet 3 to effectively allow for extension of the cutting WO 99/35345 PCT/AU99/00010 -8 fluid hose 6 as excavation progresses and the hole 29 increases in depth. Similar extension pipes may be provided to lengthen the suction hose 16. As shown in Figure 7, in another embodiment of the excavating device, a sidewall of the cutting fluid hose 6 is attached to a sidewall of the suction hose 16 such that the 5 outlet 3 protrudes beyond an inlet 30 of the suction hose 16. This arrangement is more suited to the excavation of deeper holes as compared to the arrangement shown in figure 1 wherein the cutting fluid hose 6 is separate from the suction hose 16. In the preferred embodiment illustrated in Figure 8, the pressurised cutting fluid source 2 and the suction means 5 are disposed upon a first truck 31. The storage tank 17 10 of the suction means 5 includes access means 32 to enable removal of accumulated detritus which may be drained into a second truck (not illustrated) having a separate storage tank. Hence the first truck 31, bearing the excavating device of the present invention, may advantageously remain at an excavation site whilst the second truck transports the drained detritus to a disposal site. 15 The truck 31 includes a boom 33 supporting a first portion 34 of the cutting fluid hose 6 and the suction hose 16 such that a second portion 35 of the hoses is free to hang under the influence of gravity from a distal end 36 of the boom 33. The boom 33 is telescopic to facilitate the positioning of said second portion 35 of the hoses into a position 37 to the excavated. The telescopic feature of the boom 33 is one aspect of 20 boom driving means (not illustrated) operable to control the positioning of the boom 33. Boom driving controls 38 are provided upon the console 25 which are adapted to control the boom driving means. In this way, a single operator with access to the console 25 can control the positioning of the second portion 35 of the hoses, and therefore the WO 99/35345 PCT/AU99/00010 -9 positioning of the cutting outlet 3 and the suction inlet 30. The boom 33 is pivotally mounted to the first truck 31. This enables another aspect of the beam driving means to alter the angular disposition of the boom 33 with reference to the truck 31. In another preferred embodiment (not illustrated) the hoses 6 and 16 are wound upon a spool such 5 that the outlet 3 and the inlet 30 are extensible or retractable together. The winding of the spool is automated via controls upon the console which enable an operator to remotely raise or lower the outlet 3 and inlet 30 up and/or down an excavated hole. In another preferred embodiment, the pressurised cutting fluid source 2 is connected to a manifold (not illustrated) which branches into a plurality of cutting fluid 10 hoses 6. A regulator may be included, either before or after the manifold, to regulate the pressure of the cutting fluid. This enables a plurality of users to either simultaneously excavate separate holes or to combine efforts to excavate a single hole more quickly. In another embodiment illustrated in Figure 9, a camera 39 is disposed adjacent the outlet 3. This enables a remote user to monitor the cutting and suction and is particularly 15 suited to deep excavation where visual monitoring of the hole from the surface may be difficult. The camera 39 communicates via cable 40 to a remote display screen (not illustrated). Preferably the remote display screen is disposed in close proximity to the console 25. In this manner the material being excavated can be monitored. For example, if, whilst excavating soil, a reef of rock is encountered, this may be viewed by 20 the remote operator on the display screen, and the appropriate nozzle may be attached to the hose 6. A light source (not illustrated) is disposed either on or in proximity to the camera 39 so as to illuminate a region viewed by the camera.

WO 99/35345 PCT/AU99/00010 -10 As shown in Figure 10, a gantry 41 is disposable above a region to be excavated 37 and is adapted to support a first portion 34 of said fluid and suction hoses 6 and 16 and to allow a second portion 35 of the hoses 6 and 16 to hang freely under gravity towards the region to be excavated 37. The gantry 41 includes hose positioning means 42 5 operable to control the position from which the second portion 35 of the hoses hangs. The console 25 includes hose positioning controls 43 adapted to control the hose positioning means 42. The hose positioning means 42 includes a pair of rails 44 upon the gantry 41. The rails 44 include tracks 45 along which an arm 46 is drivable, preferably by electric motors (not illustrated). The arm 46 includes a second track 47 10 disposed generally orthogonal to the first track 45. Hose engagement means 48 are drivable along the second track 47. In this manner, the gantry enables remote control of the positioning of the hoses giving two degrees of freedom along axes X and Y. In particular, the arm 46 is drivable along tracks 45 to position the hoses 35 in the Y axis and the hose engagement means 48 is drivable along the second track 47 to position 15 hoses 35 in the X axis. The preferred method for excavating according to the present invention includes the following steps: (a) providing a pressurised cutting fluid source 2 communicating with an outlet 3 adapted to spray cutting fluid (not illustrated); 20 (b) spraying cutting fluid from said outlet 3 so as to excavate material adjacent said outlet 3; and If necessary, the detritus may be de-watered by the de-watering means described above and it may also be replaced into the excavated hole upon completion of the job.

WO 99/35345 PCT/AU99/00010 -11 If services are likely to be present in the region being excavated, the step of spraying cutting fluid from the outlet 3 to excavate material preferably includes the steps of: (a) visually inspecting the excavation site to spot services as they are 5 exposed; (b) keeping the outlets 3 a sufficient distance from any exposed services to avoid damaging said services; (c) turning off the flow of cutting fluid whilst passing the outlet past the services; and 10 (d) re-commencing the flow of cutting fluid once the outlet is past the services.

Claims (43)

1. An excavating device including: a pressurised cutting fluid source communicating with an outlet adapted to spray cutting fluid so as to excavate material adjacent said outlet; and 5 suction means disposed so as to suck detritus resulting from excavated material away from said outlet.

2. An excavating device according to claim 1 wherein said cutting fluid is, or includes, water.

3. An excavating device according to claim 1 wherein said cutting fluid is, or 10 includes, air.

4. An excavating device according to any one of claims 1 to 3 wherein cutting fluid in said pressurised cutting fluid source is at a pressure of greater than 2000 psi.

5. An excavating device according to any one of claims 1 to 3 wherein cutting fluid in said pressurised cutting fluid source is at a pressure of between 3000 psi and 15 40,000 psi.

6. An excavating device according to any one of claims 1 to 3 wherein cutting fluid in said pressurised cutting fluid source is at a pressure of between 4000 psi and 20,000 psi.

7. An excavating device according to any one of the preceding claims wherein, 20 during use, said cutting fluid is ejected from said outlet at a rate of less than 200 litres per minute.

8. An excavating device according to any one of the preceding claims wherein, during use, said cutting fluid is ejected from said outlet at a rate of less than 100 litres per minute. WO 99/35345 PCT/AU99/00010 -13

9. An excavating device according to any one of the preceding claims wherein, during use, said cutting fluid is ejected from said outlet at a rate of less than 25 litres per minute.

10. An excavating device according to any one of the preceding claims wherein said 5 outlet communicates with said pressurised cutting fluid source via a cutting fluid hose.

11. An excavating device according to claim 10 wherein said outlet is a nozzle rotatably disposed upon said cutting fluid hose.

12. An excavating device according to claim 11 wherein said nozzle includes a first aperture being offset from an axis of rotation of said nozzle, said first aperture being 10 oriented such that ejection of said cutting fluid through said first aperture promotes rotation of said nozzle such that ejected cutting fluid effectively forms a cutting cone.

13. An excavating device according to claim 12 wherein said nozzle further includes a second aperture disposed opposite said first aperture such that said axis of rotation lies substantially intermediate said first and second apertures, said second aperture being 15 oriented such that ejection of said cutting fluid through said second aperture promotes rotation of said nozzle.

14. An excavating device according to claim 10 wherein said outlet is a nozzle fixedly disposed upon said hose, said nozzle including a single aperture shaped to eject said cutting fluid in a narrow stream. 20

15. An excavating device according to any one of claims 11 to 14 wherein said nozzle is selectively detachable from said cutting fluid hose.

16. An excavating device according to any one of the preceding claims wherein said suction means feeds said detritus to a storage tank. WO 99/35345 PCT/AU99/00010 -14

17. An excavating device according to claim 16 wherein said fluid is water and said storage tank includes de-watering means adapted to expel at least some of said water from said storage tank.

18. An excavating device according to claim 17 wherein said de-watering means 5 includes a pipe disposed within said tank and including a plurality of holes each disposed a various heights so as to capture water within said tank once said detritus has settled to a bottom of the storage tank.

19. An excavating device according to any one of the preceding claims wherein said pressurised fluid source includes a water reservoir and a pump acting upon water from 10 said reservoir.

20. An excavating device according to any one of the preceding claims wherein said suction means includes a suction hose acted upon by a vacuum pump.

21. An excavating device according to any one of claims 10 to 20 further including a fluid actuator disposed upon said hose, said actuator being operatively connected to a 15 valve for controlling a flow of cutting fluid through said outlet.

22. An excavating device according to claim 21 further including a plurality of extension pipes, each optionally attachable to said cutting fluid hose between said fluid actuator and said outlet so as to effectively allow for extension of said cutting fluid hose as excavation progresses. 20

23. An excavating device according to claim 20 when depended from claim 10 wherein a sidewall of said cutting fluid hose is attached to a sidewall of said suction hose and wherein said outlet protrudes beyond an inlet of said suction hose. WO 99/35345 PCT/AU99/00010 -15

24. An excavating device according to any one of the preceding claims wherein said pressurised cutting fluid source and said suction means are both disposed upon a truck.

25. An excavating device according to claim 24 when depended from claim 16 wherein said storage tank includes access means to enable removal of accumulated 5 detritus.

26. An excavating device according to any one of the preceding claims wherein said pressurised cutting fluid source is connected to a manifold branching into a plurality of cutting fluid hoses.

27. An excavating device according to any one of the preceding claims further 10 including a camera disposed adjacent said outlet, said camera communicating with a remote display screen so as to enable an operator of the excavating device to monitor cutting and suction.

28. An excavating device according to claim 27 further including a light source disposed so as to illuminate a region viewed by said camera. 15

29. An excavating device according to claim 16 further including a boom supporting a first portion of said cutting fluid hose and said suction hose such that a second portion of said hoses hangs freely under the influence of gravity from a distal end of the boom.

30. An excavating device according to claim 29 wherein said boom is telescopic to facilitate the positioning of said second portion of said hoses into a position to be 20 excavated.

31. An excavating device according to claim 29 or 30 further including boom driving means operable to control the positioning of said boom. WO 99/35345 PCT/AU99/00010 -16

32. An excavating device according to claim 32 wherein boom driving controls adapted to control the boom driving means are disposed upon a console which also includes said fluid actuator.

33. An excavating device according to any one of claims 29 to 32 wherein said boom 5 is pivotally mounted to said first truck.

34. An excavating device according to claim 10 further including a gantry disposable above a region to be excavated, said gantry being adapted to support a first portion of said fluid and suction hoses such that a second portion of said hoses hangs freely under gravity. 10

35. An excavating device according to claim 34 wherein said gantry includes hose positioning means operable to control the position from which said second portion of the hoses hangs.

36. An excavating device according to claim 35 further including hose positioning controls adapted to control said hose positioning means, said hose positioning controls 15 being disposed on said console.

37. An excavating device according to claim 34 or 35 wherein said hose positioning means include a pair of rails having a first track along which an arm is drivable.

38. An excavating device according to claim 37 wherein said arm includes a second track disposed generally orthogonal to said first track, and wherein hose engagement 20 means is drivable along said second track.

39. A method of excavating including the following steps: (a) providing a pressurised cutting fluid source communicating with an outlet adapted to spray cutting fluid; WO 99/35345 PCT/AU99/00010 -17 (b) spraying cutting fluid from said outlet so as to excavate material adjacent said outlet; (c) using suction means disposed proximate said outlet to suck detritus resulting from excavated material away from said outlet. 5

40. A method of excavating according to claim 39 wherein said detritus is replaced into the excavated hole.

41. A method of excavating according to claim 39 or 40 wherein said step of spraying cutting fluid from the outlet to excavate material includes the steps of: (a) visually inspecting the excavation site to spot any services that may be 10 exposed; (b) keeping the outlets a sufficient distance from any exposed services to avoid damaging said services; (c) turning off the flow of cutting fluid whilst passing the outlet past the services. 15

42. An excavating device substantially as herein described with reference to any one of the embodiments shown in the accompanying figures.

43. A method of excavating substantially as herein described with reference to any one of the embodiments shown in the accompanying figures.