EXCAVATION DEVICES AND METHODS
In one preferred form there is provided an excavation system (10) for a vehicle (12). The excavation system (10) comprises a body (14) for connection to the vehicle (12). An excavation device (18) is provided for being moved by the vehicle (12) to excavate material from the ground. A steering system (24) is provided for altering the steering of the excavation device (10).
In preferred forms, the present invention relates to excavation devices and methods.
BACKGROUND TO THE INVENTIONTrenching is an operation in which earth is excavated to provide a trench. Construction machines that form trenches are typically used in preparation for laying pipes or conduit.
Chain trenchers and rock wheels are typically used in the industry to form a trench, depending on the application involved. From an Occupational Health and Safety (OHS) standpoint the excavation of a trench is known to be dangerous.
The inventor, among other things, has realised that it would be advantageous to provide an improved or alternative trencher for specific applications.
Whilst a background to the invention has been provided, it is to be recognised that any discussion in the present specification is intended to explain the context of the invention. It is not to be taken as an admission that the material formed part of the prior art base or relevant general knowledge in any particular country or region.
SUMMARY OF THE INVENTIONAccording to a first aspect of preferred embodiments herein described there is provided an excavation system comprising a body; and an excavation device for being moved by a vehicle to excavate material from the ground; and a steering system for altering the steering of the excavation device.
Preferably the body is provided in the form of a keel-type structure.
Preferably the excavation device is inclined to extend towards the vehicle in the direction extending into the ground when the excavation device is being moved by the vehicle to excavate material.
Preferably the inclination of the excavation device is backwardly sloping to allow a bottom support bearing housing to clear the base of the trench.
Preferably the excavation device comprises an auger. Preferably the excavation device comprises a rotating cutting auger.
Preferably the keel-type structure shields the conduit, while being laid, from excavated earth.
Preferably the keel includes a number of projections that extend along the keel to restrain soil from falling into the bottom of the trench.
Preferably the excavation device includes auto pilot system to extend the cutting device and sweep left and right.
Preferably the steering system includes a mount having a directional joint for allowing the excavation device to be directed left or right when being moved by the vehicle.
Preferably the directional joint allows the excavation device to be readily removed for maintenance and repair.
Preferably the excavation device includes at least one hydraulic piston arranged either side of the directional joint for steering the excavation device.
Preferably the steering system is used to counteract a rotation effect of the excavation device.
Preferably the steering system allows for a swing action to be engaged in an automatic continuous swing mode.
Preferably the excavation device includes the steering system includes a deflector for varying the force applied by the ground to the excavation system to control the degree to which the excavation device turns.
Preferably the excavation device includes the steering system comprises two moveable surfaces arranged either side of the body for using friction to control the degree to which the excavation device turns.
Preferably the excavation device includes the excavation system is for the vehicle and the body is provided for connection to the vehicle.
According to a second aspect of preferred embodiments herein described there is provided an excavation system for a vehicle comprising: a body for connection to the vehicle; an excavation device for being moved by the vehicle to excavate material from the ground; and a steering system for altering the steering of the excavation device.
Preferably the steering system includes a mount having a directional joint for allowing the excavation device to be directed left or right when being moved by the vehicle.
Preferably the directional joint allows the excavation device to be readily removed for maintenance and repair.
Preferably the excavation system includes two hydraulic pistons arranged either side of the directional joint for steering the excavation device.
Preferably the steering system allows for a swing action to be engaged in an automatic continuous swing mode.
Preferably the steering system provides a deflector for varying the force applied by the ground to the excavation system to control the degree to which the excavation device turns.
Preferably the steering system comprises two moveable surfaces arranged either side of the body for using friction to control the degree to which the excavation device turns.
According to another aspect of preferred embodiments herein described there is provided an excavation system for a vehicle comprising: a body for connection to the vehicle; an excavation device for being moved by the vehicle to excavate material from the ground; and a locking system for selectively assisting with preventing the excavation device from moving backwards.
Preferably the excavation system includes an extension mechanism for extending the excavation device when the locking system is engaged to assist with preventing the excavation device from moving backwards.
Preferably the locking system comprises a wedge arrangement for bearing against the side walls of a trench formed by the excavation system.
Preferably the wedge arrangement comprises at least one movable abutment for bearing against the side walls of a trench formed by the excavation system.
Preferably the wedge arrangement comprises two moveable abutments arranged either side of the body for bearing against the side walls of a trench formed by the excavation system.
According to another aspect of preferred embodiments herein described there is provided an excavation system for a vehicle comprising: a body for connection to the vehicle; an excavation device for being moved by the vehicle to excavate material from the ground; the excavation device being connected to the body so as to be disposed forwardly of the vehicle when being moved by the vehicle to excavate material.
Preferably the body is configured such that the excavation device is disposed a substantial distance forwardly of the vehicle.
Preferably the excavation system includes a length laying guide arrangement, the length laying guide arrangement being disposed between the excavation device and the vehicle, when the excavation device is being moved by the vehicle to excavate material.
Preferably the length laying guide arrangement includes an inlet guide arrangement and an outlet guide arrangement, the inlet guide arrangement being adapted to receive a feed of conduit or cable from above in a position between the excavation device and the vehicle; and the outlet guide arrangement is adapted to provide the conduit or cable in a substantially horizontally extending position.
Preferably the excavation device is inclined to extend towards the vehicle in the direction extending into the ground when the excavation device is being moved by the vehicle to excavate material.
Preferably the excavation device is inclined by between 20 to 30 degrees away from vertical.
Preferably the excavation device is inclined by less than 25 degrees away from vertical.
Preferably the excavation device is inclined by less than 20 degrees away from vertical.
Preferably the excavation device is inclined by about 20 degrees away from vertical.
Preferably the vehicle forms part of the system, the vehicle having a loader arm adapted to lift the body above the ground for transport purposes and then lower the body into the ground for excavation purposes.
Preferably the vehicle comprises a high horse power tracked loader.
According to another aspect of preferred embodiments herein described there is provided an excavation system having an inwardly projecting excavation device and a length laying guide arrangement, the excavation device being disposed forwardly of a length laying guide arrangement to allow the excavation device to be driven forwardly and for conduit or cable to be laid therebehind.
Preferably the excavation system includes a mount arrangement for mounting to a vehicle, the length laying guide arrangement being disposed between the excavation device and the mount arrangement.
Preferably excavation device is spaced at least one meter away from the mount arrangement, the length laying guide arrangement being adapted to allow relatively stiff material to be laid in a trench.
Preferably the length laying guide arrangement includes a guide adapted to flex the conduit by about 45 degrees or less.
According to another aspect of preferred embodiments herein described there is provided a method for laying lengths in a trench comprising: positioning an excavation device in front of length laying guide and a vehicle; driving the excavation device in a forward direction using the vehicle and laying lengths using the length laying guide, the length laying guide being disposed between the excavation device and the vehicle.
Preferably the method includes filling excavated earth behind the excavation device at the same time as excavating.
Preferably the excavation system includes a vibratory arrangement for providing high frequency vibration to the excavation device.
Preferably the high frequency vibration is between 5000 to 15000 rpm.
Preferably the high frequency vibration is between 100 to 300 Hz.
Preferably the excavation system includes a vibratory arrangement for providing low frequency vibration to the excavation device.
Preferably the low frequency vibration is between 300 to 1600 rpm.
Preferably the low frequency vibration is between 10 to 50 Hz.
Preferably the excavation system includes an adjustment facility allowing the vibratory arrangement to be controlled from within the vehicle.
Preferably the low frequency vibration is aligned to assist with providing desirable back and forth vibration in the direction of travel of the vehicle and extension of the trench.
Preferably the high frequency vibration is aligned to assist with providing desirable back and forth vibration in the longitudinal direction of the auger.
Preferably the excavation system includes an air injection system for delivering air to the base of the auger.
Preferably the excavation system includes a fluid injection system for delivering fluid to the base of the auger.
Preferably in a method there is provided at least one of high frequency vibration or low frequency vibration.
Preferably in a method there is provided at least one of injection or fluid injection. Various combinations may be preferred.
According to another aspect of preferred embodiments herein described there is provided an excavation system having an inwardly projecting excavation device and a keel-type structure, the excavation device being disposed forwardly of the keel-type structure to allow the excavation device to be driven forwardly and for conduit or cable to be laid therebehind.
According to another aspect of preferred embodiments herein described there is provided an excavation system: comprising an excavation device for being moved by a vehicle to excavate material from the ground; and a keel-type structure providing a length laying arrangement for receiving a feed of conduit or cable; the excavation device for extending, into the ground to remove material to form a trench.
Preferably the excavation device comprises an auger and at least one cutter; the at least one cutter for cutting material from the cutting face of the trench; the auger providing a spoil moving mechanism for following the at least one cutter to excavate the material cut by the at least one cutter.
Preferably the keel-type structure includes a plurality of elongate platform portions that each extend along the body of the keel-type structure to prevent soil fall into the bottom of the trench.
Preferably the excavation device is supported from below by a bearing housing and is backwardly sloping in order to allow the bearing housing to readily clear the base of the trench.
Preferably the at least one grinder comprises two counter rotating milling elements.
It is to be recognised that other aspects, preferred forms and advantages of the present invention will be apparent from the present specification including the detailed description, drawings and claims.
The present invention is to be construed beneficially to the applicant.
In order to facilitate a better understanding of the present invention, several preferred embodiments will now be described with reference to accompanying
Referring to
As shown in
In the embodiment the body 14 is provided in the form of a keel-type structure 20 having a second end 22 opposite the first end 16. Moreover, the excavation system 10 includes a steering system 24 for altering the steering of the excavation device 18.
The steering system 24 includes a mount 26 having a directional joint 28 that allows the excavation device 18 to be directed left or right when being moved by the loader 12. The directional joint 28 includes a number of finger projections 30 each having an opening for receiving a mounting rod 32. Advantageously the directional joint 28 allows the excavation device 18 to be removed from the mount 26 for maintenance and repair.
In the embodiment the directional joint 28 separates the body 14 into a first portion 34 and a second portion 36. The directional joint 28 is angled to limit the weight of the second portion 36 whilst still allowing the second portion 36 to be sufficiently robust for excavation operations. The excavation device 18 is provided as part of the second portion 36. The body of the keel-type structure 20 is provided by the first portion 34.
Two hydraulic elements 38, in the form of hydraulic pistons, are provided as part of the steering system 24. The hydraulic pistons 38 are arranged either side of the directional joint 40 for steering the excavation device left or right. The hydraulic elements 38 are connected by a number of pivot mounts 42.
The hydraulic pistons 38 are positioned adjacent the top of the body 14 so as to be disposed away from the lower portion of the excavation device 18. Notably, a number of surface engagement members 44 are provided to ensure that the body 14 does not extend an undesirable depth into the ground. The surface engagement members 44 provide a horizontally extending abutment 46 for bearing against the ground.
Whilst the described steering system 24 is presently preferred other systems could possibly use deflection plates. The deflection plates may provide at least one moveable surface connected to the keel 20 that varies the force applied by the ground to control the degree to which the excavation device turns.
In this embodiment the excavation system 10 includes two deflecting plates 48. Notably the deflecting plates 48 are used for steering purposes and form part of the steering system 24.
In addition to this the deflector plates 48 provide a locking system 50 for selectively assisting with preventing the excavation device 10 from moving backwards during hard grinding. As such the deflector plates 48 both assist with sharper steering and selectively wedge the machine in the trench to assist grinding.
The locking system 50 in effect provides a wedge arrangement 52 for bearing against the side walls of a trench formed by the excavation system 10. The wedge arrangement 52 is hydraulically operated to extend outwardly such that backward movement causes rear abutment surfaces 54 of the wedge 52 to bear into the side wall of the trench. This serves to push in a longitudinal direction (in the direction of the trench) so as to restrain backward movement.
In the manner described the wedge arrangement 52 provides moveable abutments arranged either side of the body 14 for bearing against the side walls of a trench formed by the excavation system 10.
Although not shown in the drawings 1 the system 10 preferably includes an extension mechanism for extending out the excavation device 18 (the rotating cutting auger). Various forms of extension mechanism could be employed for this purpose. With the wedge arrangement 52 securing the body 14 in position the extension mechanism is able to extend the excavation device 18 for relatively hard grinding. Notably extension mechanism is also operable when the wedge arrangement 52 is not engaged.
The body 14 is relatively narrow so as to cut a narrow trench in the ground through which the body 14 passes through.
Referring to schematic
The frame 56 has a number of attachment points (not shown) for weight attachment in the case of rocky ground. The attachment points, in harder rock areas, allow weights to be attached as required to limit vibration and improve cutting. As would be apparent, weights could also be attached to the laying chute (keel) itself.
The keel 20, in addition to guiding the excavation device 18 in the ground, provides a length laying guide arrangement 64 for use in laying cable or conduit along the excavated trench. The length laying guide arrangement 64 allows the excavation device 10 to relatively slowly guide and lay conduit in the trench before filling. With the tracked loader 12 urging the excavation device 10 forwards continuous lengths 66 can be readily laid therebehind at a relatively rapid rate.
Notably while a PVC pipe laying embodiment is considered to be feasible, the use of relatively flexible polyethylene pipe (in comparison to PVC pipe) is preferred. With the use of flexible pipe the length laying guide arrangement does not have to provide the same degree of gradual curvature when bending the pipe as would be the case with, relatively stiff PVC.
The length laying guide arrangement 64 guides the continuous length 66 behind the excavation device 18, between the excavation device 18 and the loader 12. This occurs as the excavation devices moves forwardly. Advantageously the keel 20 houses the continuous length 66 as the length is laid so as to shield the length from excavated earth.
The excavation device 18 is advantageously connected to the body 14 so as to be disposed a substantial distance forwardly of the tracked loader 12. This allows the guide arrangement 64 to be relatively long and allow for gradual length flexing of the pipe as shown.
As shown in
As shown the inlet guide arrangement 68 is adapted to receive a feed of conduit from above in a position between the excavation device 18 and the loader 12. Comparatively, the outlet guide arrangement 70 is adapted to provide the conduit in a substantially horizontally extending position after flexing.
The excavation device 18 is inclined in a direction extending towards the vehicle loader 12 in the direction extending into the ground when the excavation device is being moved by the vehicle to excavate earth.
Advantageously the loader arm 72 of the loader 12 and the configuration of the excavation system 10, allows the loader 12 to lift the body 14 above the ground as shown in
When above the ground the excavation system 10 is disposed for transport purposes along roads and the like. When trenching is required the excavation system 10 is advantageously gradually lowered into the ground to commence excavation. In this embodiment the excavation 10 cuts its way down at an angle of 20 to 30 degrees.
As shown in
The depth wheel 76 is of a castor type. The castor mounted depth wheel 76 is mounted at the front and the top of the excavation system 10 so as to provide a forward facing ground engaging wheel.
As would be apparent from
In the overall system, the tracked loader 12 provides variable speed control and high traction. The tracked loader 12 also provides horse power for driving the excavation device 18. The inlet guide arrangement 68 advantageously provides for a relatively low feed angle. As discussed the particular configuration allows for the pipe to be gradually laid in the trench.
Yet further advantages include the speed of deployment and the loader operator having advantageous visibility and safer control. Furthermore, a relatively concise and consistent laying depth is provided. The pipe/cable will be laid relatively straight with relatively less laying friction for easy hauling. This is achieved by the keel 20 providing a shield as the pipe/cable is laid. In addition, the keel 20 obviates the problem of cave in prior to laying.
The trench is advantageously filled (to a degree) behind the keel 20, using the keel 20 and mole plates so as to mitigate injury liability associated with cave-ins and collapsed trenches.
In another embodiment a warning tape is laid at a lower depth using a similar laying roller arrangement with an inlet and outlet at a different depth.
As shown in
Referring to
It is envisaged that as the system is further engineered larger and larger pipe or more inflexible pipe will be able to be laid up to about say 160 mm PVC. In embodiments with PVC conduit a support boom is preferably utilized. Alternatively a platform for a worker could be provided for manual stick feeding.
The excavation system 10 is considered to provide a relatively narrow excavation/work area and to require possibly as little as 20% solid excavation compared to a bucket excavator.
The overall benefit is considered be relatively rapid continuous pipe layering that works particularly well in high water table areas. The system is considered to be relatively efficient in rock up to 50000 psi. It is envisaged that the system will be relatively efficient in rock up to 80000 psi.
There are considered to be overall operational efficiencies and for the system to present an alternative to Horizontal Direction Drilling in some applications that may avail lower cost.
The steering system 24 is considered to be particularly advantageous in situations where the excavating device 18 comprises a single auger.
Notably, with a single auger turning anticlockwise the loader driver will experience a pulling action of the augers rotation to the right (from the operator's point of view). In addition there will be a tendency of the rotating auger to feed or pack spill down the left side of the keel. These actions serve to pull the loader to the opposite direction of rotation. In the case of an anticlockwise auger these actions result in pulling to the right.
The relatively deep straight keel 20 makes steering problematic without use of the steering system 24. The steering system 24 is advantageously able to generally steer the system as well as accommodate the presence of uncompacted spoil under tracks of the machine. Electronic direction control is employed in the embodiment.
Although not presently preferred a hydraulically operated hinged deflector plate extending all the way down the right side of the laying chute may provide additional and sharper steering correction in differing ground conditions.
The presently preferred arrangement is a directional hinge allowing the auger assembly to be mounted on a support beam that is hinged onto the laying chute (guide arrangement 64).
The heavy duty hinge, in the embodiment, allows about 10 degrees of angular movement left or right. When the auger is turned to either side it cuts in that direction and the resulting earth face comes into contact with the now exposed beam side so as to act as the rudder and, advantageously, as an additional deflector plate. This is provided by the second portion 36 shown in
This performs two tasks: (i) compensation steering to counteract the rotation effect of the auger to keep the machine straight in differing ground conditions; and (ii) steering the machine through curved alignments.
Advantageously when turning corners (or otherwise) the auger swing action can be engaged into an automatic continuous swing mode such that a wider trench is formed. In addition deflector plates are able to steer the machine themselves in a much sharper radius due to presence of a wider trench. This action may be controlled by a programmed electrical circuit controlling various solenoids. Advanced electronic control is preferably provided.
At block 88, the method 82 includes positioning an excavation device in front of length laying guide and a vehicle. At block 90 the method 82 includes driving the excavation device in a forward direction and laying lengths using the length laying guide. The excavating device and length laying guide are disposed in front of the vehicle.
At block 92 the method 82 includes filling excavated earth behind the excavation device at the same time as excavating. At block 94 the method 82 includes compacting the excavated earth using a vibratory compactor attached to the rear of the vehicle.
More particularly in the method 82 a high speed cutting auger is used to emulsify the soil allowing the laying chute to pass through the ground moving the smallest amount of soil which extrudes to the surface. The tractive capability of the loader power plant combined with the design allows the laying chute to penetrate many different ground conditions.
Pipe/cable and warning tape are feed into the laying chute guide system and are set to the exact depth required. As the laying chute passes by the resulting spoil is channelled by mole boards to fill the trench immediately after the chute has passed leaving windrow on top of the incision aligned ready for compaction.
They system provides a relatively rapid one step line assembly type installation process combining: 1) trenching/plowing; 2) assembling; 3) laying conduit; 4) lay warning tape; 5) laying bedding sand; 6) backfilling spoil; and 7) compacting.
The system is readily used for areas with low to medium congestion of utilities. The system provides main benefits are high levels of construction productivity, workplace safety and responsible environmental management.
This is all completed within a small operational footprint allowing a condensed worksite. The system does this at production rates normally only achieved by larger machinery in large open areas, due to their size. They system is particularly efficient and can operate in tight boundary alignment's and tight spaces.
The new generation of high horse power (HP) compact tracked loaders is considered to be suitable for use with several envisaged systems. Such loaders have high variable ground speed control and high traction low ground pressure and are able to produce and transfer a high percentage of hydraulic HP to working implements.
The high HP allows the forward mounted auger cutting mechanism to be hydraulically driven (supported in front by a main frame incorporating a trench box laying chute). The advantageous design provides for clear vision, smaller & lighter implement weight, no complex mechanical drive angles and advantageous overall safety.
High low/low variable hydraulics power delivery is considered to allow production to be as much as 6 meters per minute (360 m per hour) by a crew of 2-3 men. This can be up to 10 times as fast compared to some systems. Higher rates such as 11 meters per minute are also considered to be possible.
The design takes advantage of the front end loader's ability to lift out the very long laying chute from the ground for transport due its long travel, the design also provides the ability to trench itself into the ground by kicking back the angle further at commencement hence there is no need for a specially excavated a starting or finishing pit.
In an embodiment, the weight is transferred to the cutting face and a clear front end and low feed angle allows for relatively stiff 50 mm PVC pipe to be threaded at a low trajectory. In the embodiment, this may allow stiffer and cheaper PCV (say at $2/m) to be laid in some situations, as against, polyethylene say at $3/m. Forward facing operator clear visibility, safer control and comfort are also provided as discussed.
Because the auger is backward sloping approximately 20 degrees it allows the placement of a bottom support bearing housing to clear the base of the trench which is cut by the lowest teeth. This bearing housing advantageously supports a long narrow auger which requires support due to its inability to be any broader due to the desired confined trench width minimization.
In some embodiments a second or mid bearing housing is placed above the auger flights that take the auger side loads induced by the pushing actions of the loader.
The narrow cutting face of the system allows relatively minimal excavation. The implement does not need to clear soil to a large windrow which in itself is a source trench collapse due to ground pressure applied by spoil weight. As there are no substantially open trenches this mitigates injury liability.
The main frame box/laying chute includes adjustable roller guides which channel the pipe or product to the desired laying position. This provides straighter pipe laying with less friction for easy hauling.
In embodiments, concise consistent pipe or cable laying warning tape placement is also provided by an adjustable depth control wheel which also assists with weight distribution.
Pipe/cable and warning tape is feed into the laying chute guide system set to the exact depth required. As the laying chute passes by the resulting spoil is channelled by otter mole boards to fill the trench immediately once the chute has passed leaving windrow on top of the incision aligned ready for compaction.
The standard model auger having carbide cutting teeth along the entire auger flight outer external surface allows extremely efficient cutting of the trench face. The auger is capable of the narrowest incision model and deals with Rock to 5,000 psi.
For rock above 5000 psi a hard rock cutter using having bullet nosed carbide cutting teeth may be used as the auger, in a first cutting pass. Notably, in soft conditions the auger could be replaced with a vibratory saw.
In softer wetter conditions the emulsifying effect of the auger on the soil will break down the structure lowering it viscosity force causing the spoil to either extrude upward or to the sides of the laying chute. This allows the system to make quickest headway for those conditions.
Drilling fluids such as water, air, bentinite and foaming agents can be injected via the leg at the rear of the auger to increase production by lowering torque. The system emulsifies the cutting to produce a more pumpable slurry spoil.
The vibratory compaction wheel is preferably designed to reach a substantial depth by compacting upwards in layers to fully expel any air/oxygen from the sub strata formation to mitigate any acid sulphate conditions through oxidation.
The system relatively minimizes disturbance and though compaction limits the chance of erosion. The system provides a green low carbon foot print methodology due its lower energy consumption. The effect on sensitive wetland areas is considered to be greatly reduced by a low ground pressure high traction/floatation capability of the loader the system is ideal for high water tables where it would normally be impossible to bury a pipe as it would float to the surface.
The operation is also relatively rapid, minimizing stress on wild life and minimal spoil means less chance destruction of sensitive habitat.
An automatic swing mode is engaged to cut a relatively wide trench and allow for the passage of material either side of the keel. Deflection steering plates are used to guide the keel. An electronic system preferably controls both the deflection plates and rotation of the auger about its pivot point.
A repetitive programmed auto pilot system of present actions would advance the trencher via the following repeated actions: A) Move to rock face by tracks; B) Expand deflector boards and lock/wedge/brace in trencher; C) Extend/jack out the rotating cutting auger; D) Sweep left; E) Sweep right; F) Retract the rotating cutting auger; and G) Repeat actions A-F.
In particular applications power could be supplied by an independent power pack for increased horse power if required. In addition the system can be used as an alternative to horizontal drilling in certain applications.
Notably apart from circular rock saws, the use of rock breakers on excavators is the most common practice. Due to the configuration and the way the breaker works the trench ends up being large V shapes resulting in 2 or 3 times as much rock having to be excavated at great time and expense, The spoil ends up as unusable boulders and has to be carted and dumped unlike the ground spoil produced by the auger. In comparison to such systems the present embodiments provide significant advantages.
Furthermore, rock saws have an inherent fault in that they can only dig as deep as the drive motor which is mounted on the axle. This means that it takes a 4 m wheel to dig a 1.5 meter hole. As a result, the machine ends up being massive and very heavy; ie 45 tons and costing say $1.5 m.
In yet further embodiments twin counter rotating augers could be used for larger trenches. Various mechanical spoil moving mechanism could be used other than otter boards such as augers and flicking paddles.
The excavation system is considered to provide a trenching/plowing hybrid system providing relatively continuous pipe and cable laying for greenfield areas. The system is considered to be relatively safe, fast and environmentally friendly. In a number of circumstances the excavation system 10 is considered to provide a better quality finished asset.
Referring to
Five energy methodologies that may suit the system comprise: (i) high frequency or sonic assist vertical motion; (ii) low frequency vibration assist vertical motion; (iii) air assist; (iv) fluid assist; (v) hammer or impact assist horizontal forward motion. Such methodologies are considered to provide liquefaction and impact assistance. A combination of such methodologies may be applied.
The embodiment of
In the embodiment, the actuator 100 has an even number of counter rotating opposing weights. The weights form a group of synchronised off set weights that are driven at high speed. Hydraulic motors provide the vibratory effect when running at about 1200 to 30,000RPM+. The high frequency vibrator 98 extends and retracts the whole assembly at a vibration frequency of between 100 to 300 Hz.
The effect is considered to provide an advantageous fluidisation of porous materials in combination with the laws of inertia. The whole auger vibrates relatively quickly. This is considered to make the material around and in front of the auger lose friction and to assist with: (i) cutting—on the cutting edge it aids penetration as it melts into the face of the excavation; and (ii) transport on the auger flights making the material flow more like liquid.
This intense vibration is considered to cause a very thin layer of particles directly surrounding the auger to lose structure. Instead of the stiff mass that requires torque and weight to penetrate, the soil behaves more like a fluid powder. Fluidisation or liquefaction is considered to reduce the friction between the auger and the surrounding formation. This is considered to allow relatively rapid penetration of the auger reducing the energy required for forward motion and auger drive. A more efficient cutting action is considered to be provided.
In addition the high frequency vibration of between 100-300 Hz is considered to prevent the formation from sticking to the flights of the auger.
The high frequency vibrator 98 includes a vibration adjustment facility accessible by the driver (operator) of the system from within the vehicle. The operator is able to vary the frequency to match the material in which the trench is provided, to allow adjustment to provide an advantageous penetration rate. Smaller machines can also be built than might otherwise have been the case.
In various vibratory arrangements, simultaneous dual frequency vibrations may be able to be induced (high and low) by different mount positions of the actuator 98. A mounting position of the actuator directly on the auger assembly 106, or on frame of the device is preferred.
Referring to
By the varying the placement of any such attachment on the implement the vibration or impact can be controlled i.e. the oscillating device slews through degrees of orientation being moved in position by a hydraulic ram so as to pivot and direct its energy in a preferred direction up down or sideways. Various arrangements are possible.
One schematic arrangement shown in
The frequency of the vibration is adjustable. In this embodiment the vibration is hydraulically powered. The frequency is adjustable by controlling hydraulic flow to best suit ground conditions.
Referring to
The connection 132 can be considered as a steering assembly hinge 142. In the case of high frequency the slack in the steering assembly hinge may provide say 0-15 mm travel. The applicant is yet to determine whether such travel should be increased or decreased. Returning to
Notably the lower frequency vibrator 102 provides primary movement in the direction 144. The low frequency vibrator 102 bounces on a wheel 146 that contacts the ground. This may provide say 0 to 35 mm travel between the machine and the front tyre due length of leverage and the low pressure of the tyre to enable bouncing to act and a non-rigid pivot. As such the tyre acts as a spring compressing and decompressing with the action of the low frequency vibrator 102 (provided be the inertia of the roto-motion of the driver counter weights).
In the low frequency vibrator 102, the offset weights are of a much heavier build, which produces a longer slow, and strong stroke. Such a stroke also advantageously physically forces the cutting teeth into the formation which is considered to be relatively advantageous in hard ground conditions and rock. The action is considered to produce a ripping and shearing action producing a particle size conducive to an advantageous flow rate. This is measured by the operator noting the forward travel speed as he varies and adjusting to suit local conditions. The lower frequency vibrator 102 includes a vibration adjustment facility accessible by the driver (operator) from within the vehicle.
The low frequency vibrator 96 is positioned to provide relatively vertical vibration. The high frequency vibrator 98 is mounted so that its action is directed to the auger drive rod as much as is feasible such as by mounting to the casing. The vibration action is substantially perpendicular to the longitudinal axis of the auger. The lower frequency vibrator 102 is fixed on the frame spaced away from the suspended air bag tyre 104 as shown in
It is considered that conventional rock wheels or chain trenchers are not as advantageously adapted to the inclusion of such a vibratory arrangement 96 due to their physical mass in the case of the rockwheel and associated design restrictions such the chains slop and isolation of the action by its no ridged linkage.
In another embodiment an air injection system is provided. The air injection system delivers air at the bottom of the trench at the base of the auger assembly. A delivery rate of about 80 to 120 cubic feet per minute is preferred in the embodiment. Air fluidization is a process similar to liquefaction whereby a granular material is converted from a static solid-like state to a dynamic fluid-like state. This process occurs when a fluid (liquid or gas) is passed up through the granular material.
As detailed on Wikipedia:
-
- ‘When a gas flow is introduced through the bottom of a bed of solid particles, it will move upwards through the bed via the empty spaces between the particles. At low gas velocities, aerodynamic drag on each particle is also low, and thus the bed remains in a fixed state. Increasing the velocity, the aerodynamic drag forces will begin to counteract the gravitational forces, causing the bed to expand in volume as the particles move away from each other. Further increasing the velocity, it will reach a critical value at which the upward drag forces will exactly equal the downward gravitational forces, causing the particles to become suspended within the fluid. At this critical value, the bed is said to be fluidized and will exhibit fluidic behaviour. By further increasing gas velocity, the bulk density of the bed will continue to decrease, and its fluidization becomes more violent, until the particles no longer form a bed and are “conveyed” upwards by the gas flow.
- When fluidized, a bed of solid particles will behave as a fluid, like a liquid or gas. Like water in a bucket: the bed will conform to the volume of the chamber, its surface remaining perpendicular to gravity; objects with a lower density than the bed density will float on its surface, bobbing up and down if pushed downwards, while objects with a higher density sink to the bottom of the bed. The fluidic behaviour allows the particles to be transported like a fluid, channelled through pipes, not requiring mechanical transport (e.g. conveyor belt).’
In other embodiments a fluid assist unit may find application. As with down hole drilling a range of different liquids can be introduced to enhance efficient production detergents for stick clays, slippery polymers to enhance cutting water to dampen dusts cool the cutters down.
In another embodiment an impact hammer is provided. In the embodiment the impact hammer provides a knocking hammer action attached in much the same way as the vibrator placed on the auger assembly. The impact hammer could act in a horizontal or North-South latitude rather that up and down action.
Other action impact may be provided, as in horizontal hammering by the fitting of a percussive hammer similar in action to a rock breaker or impact ripper. This method may vary from the vibratory actions of high and low frequency in that it travel is action is horizontal and or it may or may not take the form of an impact. Various orientations are possible.
In another embodiment continuous laying is provided. For example a substance could be pumped into the laying chute so as to extrude a continuous foundation or barrier. Concrete or another substance may be suitable.
In order to assist with maximizing the efficiencies of the system, in the many differing ground conditions and differing applications, different embodiments will be produced in various models and capacities and may be as multi-purpose as a possible buy configuration of the system allows. A variable build size matched to the primemover suited to application depth width and ground type is envisaged.
Embodiments may have different milling heads including the following cutting milling auger configurations to suit ground conditions (refers to current model only): (i) 70 mm Rod/Dual fight/low pitch/Bullet cutters; (ii) 70 mm Rod/Single flight high pitch Shark teeth; (iii) 70 mm Rod/Dual fight loe pitch Shark Tether; (iv) 125 mm/Barrel reamer/low pitch/Air assist; (iv) 125 mm/Barrel reamer/high pitch/pizza cutters.
Various methods embodying the invention may provide for high frequency vibration, low frequency vibration, air assist and fluid assist. Preferred systems preferably provide an automated programmable repeated action for hard rock milling through by wedging and hydrolic pressure to provide high psi purchase leverage capability.
In one embodiment, when the machine is in the trench in hard ground conditions, the mechanism provides: 1) the mechanism hydraulically extends to the sides of the trench to wedged to hold the machine form being pushed backwards; 2) the front cutting head hydraulically extends forward will cutting approx. 300 mm; 3) The head then swing side to side cutting to desired width and then retracts; 4) The wedges them release and retract; 5) The machine tracks forward 300 mm. The cycle is then repeated.
An excavation system 148 according to another preferred embodiment is illustrated in
The excavation arrangement 154 includes an excavation device 158 and a keel-type structure 162. The excavation device 158 is provided in the form of an auger 160. The excavation arrangement 154 is provided to be driven forwardly to provide a trench. Referring to
In a number of embodiments, the angle of repose of the auger is 20 degrees or more. This allows the cutters at the base of the auger to cut below the depth of the base bearing housing and support providing a clear path for the bearing and support to travel. The base bearing housing and support are up and under the auger. The angle of inclination may be selected to suit the cutting conditions.
Returning to
The excavation device 158 is provided for being moved by the vehicle 150 to excavate material form the ground to provide a trench. The keel-type structure 162 provides a length laying arrangement for receiving a feed of conduit or cable. In a trenching condition the excavation device 158 extends a longitudinally into the ground to define a trench depth.
As shown there is provided a frame 166 having a structure 167 and a carriage 168. The carriage 168 includes four wheels. The carriage 168 is connected to the structure 167 by a connection 170. The connection 170 comprises a member having a first pivot 172 and a second pivot 174.
In embodiments an arrangement comprising a locking portion and an abutment is provided to secure the first pivot 172 to provide the raised condition 156 and a deployed condition 180 for providing a trench.
A steering system 182 is provided in the form of a rudder 184 at a rearward end of the excavation assembly 154. The rudder 184 extends the height of the keel-type structure 162.
The first pivot 172 allows 90 degrees of movement between secured conditions. From the raised condition 156 to the deployed condition 180 the carriage 168 flattens and moves toward the tractor 152 as shown. The carriage includes a recess 186 for receiving the structure 1676 which is provided as a beam. The recess 186 moves from a vertically inclined condition facing forwardly to a horizontally inclined condition facing upwardly, as the excavation assembly 154 moves from the raised condition 156 to the deployed condition 180. The recess 186 is sized to receive the beam.
In another embodiment shown in
In the context of several embodiments, present optic fibre ploughing through hard solid ground even with heavy dozers can take many passes to get a desired depth of say 1200 mm. This is because the ground generally gets harder the deeper one goes. Often the dozer must have heavy mass i.e. 60 tons+traction+ and large horsepower. Such dozers are expensive to own and operate and need special permits and heavy haul equipment to move. Ripping or pre-ripping expends energy directly against the earth.
In the embodiments the earth is loosened at the point of contact by a milling action to cut and relieve the solid formation. This is considered to be able to be done using cheaper lower horse power agricultural tractors that have PTO power take off to produce the rotational action.
Normally agricultural HP is used on very wide large implements to cover thousands of acres at shallow depth. Here there is a concentration all that power is provide on say a 250 mm wide slot 1200 mm deep. A steering keel is used in various embodiments. Heavy weighting is used on rear to hold down the cutters as required.
Double barrel augers or milling heads (2 or More) may be used. Either intermeshing as shredders or segregated by gap of desired crushing's sizes rotating as opposite pairs clockwise feeding spoil in through centre or counter clockwise out to the side of the cut trench. Counteracting lengths should have little effect on steering as far as pulling machine off line as they counter balance each other. The designed configuration purpose of these cutters may be to act as milling heads as primary purpose and therefore could be mounted in a triangle with a 3rd auger purely for lifting spoil out after the front 2 augers cut and grade the spoil and passed it backwards.
The system is considered to be particularly good for floating rock i.e. were a solid formation of baked clay has solid boulders within the formation as they process the boulder as the move forward. This is a problem for chain and saw trenchers as they could try to lift the whole boulder though the solid-earth causing high impact and damage as the bolder bounces in elongating hole with each impact.
In one preferred method, according to an embodiment, there is provided provide power assisted ploughing using a milling auger mounted on steering rudder to cut and transport the spoil to the surface relieving a narrow channel and clearing the path for a laying keel reducing energy required to open the formation.
The method is considered to advantageously distribute energy in a relatively effective way allow say a prime mover to be smaller and lighter in comparison to a number of existing systems that need to exert as much 200 tons of drawbar force to break hard ground.
The method advantageously allows the design of efficient machines, having configurations matching a variety of ground conditions from rock condition to below the water table. In various forms high and low frequency vibration liquid and air injection are mounted on various prime movers.
In embodiments there is considered to be applications to subsea ocean floor pipe and cable laying with the use of remotely operated vehicles. Application may also be found in: continuous laying deep concrete foundation diaphragm piling walls; agricultural drainage PTO drive trailed devices; self-propelled excavator mounted larger diameter installations; and other applications.
In embodiments, 1 to 7 tonne excavations may be used. Development of a larger models that fits on larger excavators of say 20 tons+ are possible—they make an suitable prime mover having the weight, hydraulic flow, power, capability of variable traction control enabling the easy conversion. This is considered to provide an alternative to very expensive single purpose self-propelled trenchers as are presently available.
Various methodologies employ fluid assist, air assist, hammer or impact assist horizontal forward motion, low frequency vibration assist vertical motion, sonic assist vertical motion, and combinations thereof. In order to accommodate the many differing ground conditions and differing applications size and depth of trench the machine will vary in various models and sizes.
One definition of trenchless technology is ‘any technique, process or procedure, including the equipment, machines and materials involved, which minimises or eliminates the need for surface excavation or reduces environmental damage or reduces the associated costs for underground work.’
Since 2006 plowing technology (cable plow/mole plow technology) has been accepted as a trenchless technique. The embodiments described are considered, at least to some extent, provide a trenchless technology.
Some embodiments are considered a trenchless process or a beneficial process that for example sits between HDD horizontal directional drilling say at $45 per meter for 50 mm pipe being more expensive and ploughing being more disruptive but cheaper say at $25 per meter 50 mm pipe on cost basis.
In a number of embodiments there is provided a power assisted rotating milling auger plow trencher and pipe and cable laying mechanism that vibrates and injects fluids and gases while bracing itself in the trench and jacking forward to bare massive thrust on the trench face by automated repeat actions. Some embodiments may of course only utilize some of the above actions.
In one test the applicant has found that rate the mechanism is at least capable of effectively cutting soft to medium rock up to 8000 psi or 3 moh's hardness scale at 30 meters per hour.
Embodiments may include:
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- Hydrolic driven attachment
- Attachment version with direct drive on board motor 150 Hp
- Agricultural tractor drawn 400 Hp PTO drive Trailed device
- Self-propelled on tracks
- Excavator mounted larger diameter installations
- Subsea ocean floor pipe and cable laying Mounted to ROV
- Continuous laying deep concrete foundation diaphragm Piling walls.
- Other uses to be identified
Various embodiment use a milling auger mounted on steering rudder to cut and transport the spoil to the surface relieving a narrow channel and clearing the path for the laying keel reducing energy required to open the formation. This process is considered to apply energy i.e. HP in a relatively effective way allowing the prime mover to be smaller lighter as some existing systems need to exert as much 200 tons of drawbar force to break hard ground.
If compared to the only 2 common trenchers mechanisms which chain cutters or rock wheels the systems have many benefits, it is efficient and compact. The configurations vary to match application and variety of ground condition form rock to below water table.
There are a number of distinct potential build configurations. The configurations may utilize various forms of enhancement such as high and low frequency vibration liquid and air injection.
Existing products includes: Excavators 1 . . . 7 ton; Excavators 7 . . . 20 ton; Excavators 20 . . . 35 ton; Large Rock wheel Tesmech 1100; Agricultural Drainage Plow Bron; Agricultural Drainage Plow attachment Gold digger; Static Dozer Plows CAT D8; Plow attachments Bron; Vibratory Plow Vermeer Renegade; Small Vibe plow Vermeer 120t Small Rock wheel Case 960; Small Chain Trencher Ditchwitch RT115; Large Chain trencher Mastenbrock; Spider Plow Fokersperge; Caditcha D9 Telstra; Sub Sea ROV Mounted SubSea; Eco trencher USA.
We perceive a mass market in the subsequent range of designs that will encompass various plants capabilities. For example development of a larger models that fit on larger excavators of say 20 tons+. They are envisaged to make a prime mover having the weight, hydraulic flow, power, capability of variable traction control enabling easy conversion. There are a number of such larger excavators throughout the world and they are comparatively cheap. This would be an alternative to very expensive single purpose self-propelled trenchers.
Configuration Variables: Size and Prime mover it fitted to suit application; 5× Auger/Miller configuration to suit ground conditions; 5× Energy assist methodologies that suit the system all causing some form of liquefaction (Fluid assist; Air assist; 3 Hammer or impact assist Horizontal Forward motion; 4. Low frequency vibration assist Vertical Motion; Sonic assist Vertical Motion). Or any combination of one or more of the above methodologies.
In order to allow for any one of the many differing ground conditions and differing applications size and depth of trench the machine will be in various models and sizes multi-purpose as possible buy configuration of the implement. A family of machines will have different capabilities and attributes.
Rock capabilities are generally specified in the following ranges: soft rock (0-6 kpsi), medium rock (7-12 kpsi), medium hard rock (13-25 kpsi) and hard rock (26 to 45 kpsi)
Initial trails have concluded that the prototype mechanism is capable of effective cutting soft to medium rock up to 8000 psi or 3 moh's hardness scale at (the cutting being at a production 30 meters per hour). The steerable keel keeps the machine traveling straight with steering due to the sideways pulling effect of rotational action of the milling auger
One of the advantages is that embodiments can be provided as an attachment that means machine expenditure is relatively low compared to single purpose specialist trenchers. In embodiments there is considered to be provided a trenchless technology that sits as example between HDD horizontal directional drilling $45 per meter for 50 mm pipe being more expensive and ploughing being more disruptive but cheaper $25 per meter 50 mm pipe on cost basis
The extreme heavy work load environment has meant we have had to developed a special base support arrangement for the bottom end assembly which works as the rotational bearing and the quick release auger change out system
It is to be appreciated that each of the embodiments is specifically described and that the present invention is not to be construed as being limited to any specific feature or element of any one of the embodiments. Neither is the present invention to be construed as being limited to any feature of a number of the embodiments or variations described in relation to the embodiments.
It is to be recognised that various alterations and equivalent forms may be provided without departing from the spirit and scope of the present invention. This includes modifications within the scope of the appended claims along with all modifications, alternative constructions and equivalents.
There is no intention to limit the present invention to the specific embodiments shown in the drawings. The present invention is to be construed beneficially to the applicant and the invention given its full scope.
In the present specification, the presence of particular features does not preclude the existence of further features. The words ‘comprising’, ‘including’ and ‘having’ are to be construed in an inclusive rather than an exclusive sense.
Claims
1-41. (canceled)
42. An excavation system comprising: a body; and an excavation device for being moved by a vehicle to excavate material from the ground; and a steering system for altering the steering of the excavation device.
43. An excavation system as claimed in claim 42 wherein the body is provided in the form of a keel-type structure.
44. An excavation system as claimed in claim 42 wherein the excavation device is inclined to extend towards the vehicle in the direction extending into the ground when the excavation device is being moved by the vehicle to excavate material.
45. An excavation system as claimed in claim 42 wherein the inclination of the excavation device is backwardly sloping to allow a bottom support bearing housing to clear the base of a trench.
46. An excavation system as claimed in claim 42 wherein the excavation device comprises an auger.
47. An excavation system as claimed in claim 42 wherein the body is provided in the form of a keel-type structure and the keel-type structure shields the conduit, while being laid, from excavated earth.
48. An excavation system as claimed in claim 47 wherein the keel-type structure includes a number of projections that extend along the keel-type structure to restrain soil from falling into the bottom of the trench.
49. An excavation system as claimed in claim 42 having an auto pilot system to extend the cutting device and sweep left and right.
50. An excavation system as claimed in claim 42 wherein the steering system includes a mount having a directional joint for allowing the excavation device to be directed left or right when being moved by the vehicle.
51. An excavation system as claimed in claim 50 including at least one hydraulic piston arranged either side of the directional joint for steering the excavation device.
52. An excavation system as claimed in claim 42 wherein the steering system is used to counteract a rotation effect of the excavation device.
53. An excavation system as claimed in claim 42 wherein the steering system allows for a swing action to be engaged in an automatic continuous swing mode.
54. An excavation system as claimed in claim 42 wherein the steering system includes a deflector for varying the force applied by the ground to the excavation system to control the degree to which the excavation device turns.
55. An excavation system as claimed in claim 42 wherein the steering system comprises two moveable surfaces arranged either side of the body for using friction to control the degree to which the excavation device turns.
56. An excavation system as claimed in claim 42 including a locking system for selectively assisting with preventing the excavation device from moving backwards.
57. An excavation system as claimed in claim 56 wherein the locking system comprises a wedge arrangement fir bearing against the side walls of a trench formed by the excavation system.
58. An excavation system as claimed in claim 57 wherein the wedge arrangement comprises at least one movable abutment the or each for bearing against a corresponding side wall of a trench formed by the excavation system.
59. An excavation system as claimed in claim 42 wherein the body is provided for connection to the vehicle; the excavation device being connected to the body so as to be disposed forwardly of the vehicle when being moved by the vehicle to excavate material.
60. An excavation system as claimed in claim 42 including a length laying guide arrangement, the length laying guide arrangement being disposed between the excavation device and the vehicle, when the excavation device is being moved by the vehicle to excavate material, the length laying guide arrangement including an inlet guide arrangement and an outlet guide arrangement, the inlet guide arrangement being adapted to receive a feed of conduit or cable from above in a position between the excavation device and the vehicle; and the outlet guide arrangement being adapted to provide the conduit or cable in a substantially horizontally extending position.
61. An excavation system as claimed in claim 60 wherein the excavation device is inclined by between 20 to 30 degrees away from vertical.
62. An excavation system having an inwardly projecting excavation device and a length laying guide arrangement, the excavation device being disposed forwardly of a length laying guide arrangement to allow the excavation device to be driven forwardly and for conduit or cable to be laid therebehind.
63. An excavation system as claimed in claim 62 wherein excavation device is spaced at least one meter away from the mount arrangement.
64. An excavation system as claimed in claim 62 wherein the length laying guide arrangement includes a guide adapted to flex the conduit by about 45 degrees or less.
65. A method for laying lengths in a trench comprising: positioning an excavation device in front of length laying guide and a vehicle; driving the excavation device in a forward direction using the vehicle and laying lengths using the length laying guide, the length laying guide being disposed between the excavation device and the vehicle.
66. A method as claimed in claim 65 including automatically moving the excavation device left and right to counteract a rotation effect of the excavation device
Type: Application
Filed: Oct 22, 2013
Publication Date: Oct 8, 2015
Applicant: FUTURE CONSTRUCTION & CIVIL PTY LTD (PERTH)
Inventor: James Johnson (Perth)
Application Number: 14/437,309
