AU2006241325A1 - An apparatus and method for the movement of irrigation spans - Google Patents

Description

23/11 '06 THU 15:33 FAX 61 8 82119433 Lesicar Perrin 015 13496

ORIGINAL

Complete Specification

~I

Applicant: Title: Irrigation Systems and Components Australia Pty Ltd An apparatus and method for the movement of irrigation spans LESICAR PERRIN, 49 Wright Street, Adelaide, Scuth Australia 5000, Australia Address for Service: The following statement is a full description of this invention, including the best method of performing it known to melus: COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THU 15:33 FAX 81 8 82119433Leca Prrntii Lesicar Perrin Zo16 IN2 o An Apparatus and Method for the Movemnent of irrigation spans FIELD OF THE INVENTION Z The present invention relates to an apparatus anid method for the movement of irrigation spans. In particular, the uniform movemnent of connected irrigation spans used for the purpose of irrigating land.

BACKGROUND OF TEE INVENTON T'he irrigation of large expanses of land can be achieved by connecting two or more irrigation spans and traversing these through a field. Thie movemnent of such an irrigation device is automated so as to eliminate the need for any personnel during oprtin The automated movement of multiple linked irrigation spans has typically been achieved using a centre pivot type irrigation device, whereby irrigation spans m3e rotated around a stationary centre tower. The stationary centre tower is usually tieCdt) the ground using fixed attachment points or additional weight Also, the tower includes a means of receiving, or pumping, water from a water source and distributing it, at a suitable pressure, along overhead conduits through the connected irrigation spans. The water supply is then dispersed to thie irrigated field-by nozzles, located on each irrigation span, adapted to release a consistent amount of watr- The irrigation of mainly circular expanses of land is not ideal and results in inefficient use of the land. It is obviously more desirable to use and irrigate all of the available land in order to increase the yield of the crop being grown as well as utilising the shape of the land. In order to use all of the land effectively, a centre pivot irrigation device can be adapted to irrigate the four corners of the field or, alternatively, a linear move irrigation device can be used. The linear move system has, the advantage of more effectively and efficiently irrigating larger expanses of rectangular and irregularly shaped fields.

In both centre pivot and linear move devices, generally each irrigation span is powered by its own drive system and therefore requires an arrangement for both guiding the movement of the device and maintaining relative consistent movement of COMS ID No: SBMI-05450615 Received by IP Australia: lime (I-tm) 16:15 Date 2006-11-23 23/11 '06 THU 15:33 FAX 81 8 82119433 LscrPri 1 Leslear Perr1n [a 017 3 IN each of the connected irrigation spans. The guidance Of a linear Move irrigation o device is typically achieved using a guide wire or a guide furrow, whereby a travel]ling guide arm follows the wire or furrow and translates any deviance in the path as a o signal to alter the movement of the irrigation device. Other methods of guiding the movement of the device include the use of; GPS, compasses and electromagnetic ci radiation- There are problems with both methods with the latter involving expensive, sensitive sensory equipment, and the furrows and guide wires requiring regular in maintenance and correct installation.

Prior art methods of maintaining alignment betweent irrigation spans include the us of: a strain gauge to ascertain the variance in -position between adjacent IND irrigation spans, velocity sensors placed on individual spans to detect if a particular O span is travelling too fast or too stow, angular movement sensors and mechanical linkages to send a signal to the controller that a particular span is out of alignment.

These mechanical linkages provide an inaccurate measurement of the movement between irrigation spans. The prior art solutions only provide the controller with a reading as to where each span is relative to the other and their relative speed- The prior art does not provide information as to the rat of movement between adjacent spans. Also, typically a signa is sent to the controller to alter the speed of a span once one of the sensory devices have received a signal indicating a span has reached its predetermined limit. This is not ideal and an inaccurate solution to coordinating the morvement of linked irrigation spans, rior art methods of controlling the individual drive systems for each irrigation span arc also typically inaccurate. They involve the switching of individual motors, located on each irrigation span, on and off, thus, placing undue stress on the respective motors and gearbox assemblies. This basic level of control also does not allow for a consistent rate of irrigation across the entire field. As a result, most linear move irrigation devices are not suitable for the distribution of berbicides and pesticides in the water being discharged. in order roprovide a consistent water distribution to the field being irrigated both a greater level of pumping control and movement is required. The stop-start motion of such irrigation devices results in a slower time to traverse the length of the field and the use of more water than optimally required.

COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THUT 15:34 FAX 61 8 82119433 Leslcar Perrln So018s 4 I Another disadvantage of the prior art irrigation devices is that they typically o cannot operate in both linear move and centre pivot modes without the need for the tower to be tied down whilst pivoting. A greater expanse of land can be irrigated if the O irrigation device can pivot 180 degrees without the need for personnel to tie the tower down. The land adjacent to the area already irrigated can be irrigated automatically 3y Ci pivoting the device 180 degrees then traversing the device through the field laterally in the opposite direction of travel. Prior art methods of pivoting an irrigation device, V) without tying down, are inaccurate and can result in damage to property caused by en any uncontrolled movement It is therefore an object of the present invention to overcome the ISN aforementioned problems and to provide the public with a useful alternative.

C SUMMARY OF THE INVENTION Therefore in one form of the invention there is proposed an irrigation device including: at least one driving means adapted to move said irrigation device along a predetermined path and at least one sensing means adapted to prevent said irrigation device from deviating from the predetermined path.

Preferably said driving means is mounted to an irrigation tower and is mounted at one end of each irrigation span.

Preferably said sensing means includes at least one potentiometer whereby said potentiometer's stroke length is measured and sent to a controller for comparison with a desired potentiometer stroke length range calculated for travel along said predetermined path and at a predetermined speed whereby said controller sends a signal to alter the speed of said driving means accordingly thus returning the measured potentiometer stroke length to its desired range.

Preferably said irrigation tower includes a guidance mechanism including a sensing means and at least one mechanical linkage adapted to support at least one guide arm, whereby said guide arm is adapted to follow a guide forming the predetermined path.

COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THU 15:34 FAX 61 8 82119433 LscrPri 1 Lesicar Perrin [a 019 VaO o Preferably said guide is a wire extending the length of the predetermined path 0 and fixed at a predetermined height above a field.

o Preferably said guide arm is adapted to move horizontally above the field and Z said horizontal movement is transposed through at least one said mechanical linkageinto a change in the potentiometer stroke length of the sensing means whereby said stroke length is analysed by the controller and adapted: for use in maintaining the substantially parallel movement of the irrigation tower relative to said guide.

Preferably said guide arn is adapted to receive said guid e with a grooved rotating wheel located on the extremity of said guide arm.

Preferably said irrigation span is coupled to said irrigation tower and 0 additional said irrigation spans are connected to the previously connected irrigation spans in a series arrangement whereby said connected irrigation spans include a connection mechanism at one of end of said irrigation spans whereby said connection mechanism further includes said sensing means.

1s Preferably said connection mechanism is further adapted to ensure the movement of said connected irrigation spans along the predetermined path by at least one mechanical linkage adapted Lo transpose relative movement between said connected irrigation spans into a change in the potentiometer stroke length of the sensing means whereby said stroke length is measured, sent to a controller, and compared with a desired potentiometer stroke length range whereby said controller sends a signal to alter the speed of said driving means accordingly thus maintaining the substantially linear movement of the irrigation span relative to said adjacent unrgation span.

Preferably said irrigation tower includes a pivotable connection between said irrigati on tower and the firt irrgation span whereby said plurality of connected irrigation spans are adapted to be rotated about the irrigation tower.

Preferably said irrigation tower includes two independently operated said driving means adapted to move in both forward and rearward directions and in both a pivotal or linear manner- COMS ID No: SBMI-05450615 Received by IP Australia: Time (I-tm) 16:15 Date 2006-11-23 23/11 '06 THU 15:34 FAX 61 8 82119433Leca'ern00 Les1car Perr1n [a 020 6 oN Preferably said independent driving means further include an electric motor o connected to a pair of wheels via a gearbox.

o Preferably said wheels ame adapted to traverse all terrains.

Preferably said controller mnonitors the potentiometer stroke length of all the irrigation device potentiometers and said controller compares the measured potentiometer stroke length with the desired range of potentiometer stroke length whereby if the measured stroke length deviates from the desired operating stroke Cfl length range said corresponding electric motors are adapted to alter their speed so as to return the potentiometer stroke length back to the desired range.

oN 1 Preferably said irrigation tower further includes a water intake point and a 0 power intake point for distribution throughout the irrigation device.

Preferably said connection mchanism between said irrigation spans fturther includes a flexible conduit adapted to connect a water bearing conduit located on Oo; said irrigation span with another water bearing conduit on the adjacent irrigation sp~an.

Preferably said water bearing conduit includes a plurality of vertically mounted connections adapted to WInmiL water to a plurality of sprinkler heads adapted to release water a fixed rate.

Preferably said controller includes at least one variable frequency drive unit for the control of said electric motors.

BRIEF DESCRIPTON OF ThE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention.

In the drawings: Figure 1 illustrates a front view of an irrigation device with two or MOre irrigation spans connected; Figure 2 illustrates a front view of an irrigation device tower, COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THU 15:35 FAX 61 8 82119433 Lesicar Perrin @o21 7 o Figure 3 illustrates a front view of the connection between two irrigation 0q spans; o Figure 4 illustrates a closer perspective view of the connection between Z two irrigation spans; Figure 5 illustrates a top view of the irrigation device guidance mechanism, located on the irrigation device tower; en Figure 6 illustrates a top view of the movement control arrangement located on the irrigation device tower, c-, Figure 7 illustrates a top view of the movement control arrangement located on each connection between irrigation spans; c-, Figure 8 illustrates a side view of the driving mechanism, located on both sides of the irrigation device tower and on one end of each irrigation span; Figure 9 illustrates a top view of the drive mechanism and gearbox arrangement located on both sides of the irrigation device tower and on one end of each irrigation span; Figure 10 illustrates a front view of the irrigation device controller unit; and Figure 11 illustrates a front view of the irrigation device controller unit with variable frequency drive units displayed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the invention refers to the accompanyin.g drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention.

Figure 1 shows an irrigation device 10 including at one end an irrigation device tower 12 and in series a first irrigation span 14, a second irrigation span 16, COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THU 15:35 FAX 61 8 82119433 Leslcar Perrin 21022 o and a third irrigation span 18. It is envisaged that a plurality of irrigation spans can be connected and driven in either centre pivot mode, whereby the plurality of irrigation spans rotatably move about the stationary irrigation tower 12, or in linear move mode, 0 whereby the plurality of irrigation towers and the irrigation device tower move in unison linearly across the field being irrigated.

The motion of an irrigation device with its connected irrigation spans, in titler linear or centre pivot mode, was previously achieved using limit switches attached C' between adjacent irrigation spans. These limits were predetennined and if an irrigation span struck its limit switch, power would be cut to the electric motor drivag C, 10 the ground engaging wheels of that particular irrigation span. This stop-start motion No places undue stress on the electric motor and gearbox assemblies of each connected o irrigation span and as a result is less reliable, requires more maintenance, and the irrigation device has a shorter usable lifespan.

To solve the abovementioned problems many methods of adjusting the speed of the connected irrigation spans can be used- One particular method is the use of variable frequency drive motors and controllers. This provides the ability to speed up and slow the connected irrigation spans thus reducing stress on the individual motors and gearbox assemblies.

The present invention further still uses sensory devices to give an even finer control of the movement of the irrigation device. These sensory devices placed on each irrigation span to monitor the alignment between adjacent irrigation spans and alter the speed of the electric motor driving the corresponding irrigation span accordingly. A connected irrigation span moving out of alignment is accelerated or decelerated, relative to the adjacent span, to maintain the desired alignment. These sensory devices are preferably potentiometers, as they allow for an accurate reading of the angle of adjacent irrigation spans. The relative position of adjacent inigation spars and the relative rate of movement away from alignment are measured by the potentiometer and this information is used to accelerate or decelerate the corresponding electric motor to ensure consistent movement of the irrigation device.

This fine level of alignment control is achieved using variable frequency drive units t3 control the electric motors. Such drive units can be used to adjust electric motor speed COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THIS 15:35 FAX 61 8 82119433 LscrPri 2 Lesicar Perrin [a 023 9 oN quiickdy and accurately, preserving the motor and gearbox assemblies from excessivz, 0 wear and maintaining a sm-ooth motion for the irrigation device traversing the field.

o Figure 2 shows the irrigation device tower 12 comprising a base Z supporting -a tower frame 22, gearbox assemblies 24, and electric motors 26 (only the left hand side motor is shown in this figure) for thie propulsion of the irrigation devioe tower 12. The propulsion of thc tower is achieved through a plurality of round engaging wheels 28, In this embodiment, the tower is supported by four wheels, witb Cl each side having its own motor and gearbox arrangement to provide a steering capability.

The irrigation device tower 12 also includes a water intake point 30, where o water enters the irrigtion device to be distributed over the field. This water source ii; Cl either pumped directly from a canal running parallel to the direction of travel of the irrigation device 10, or from a central point. The water enters a vertical conduit 32 and passes through a swivel point 34, allowing for the attached irrigation spans to pivot around the irrigation device tower 12. The water then enters the overhead conduit 36 of the attached irrigation spans for distribution.

The irrigation device tower 12 has a guidance system to guide the tower acrojs the field in the desired fashion. This system comprises a guide arm 38, adapted to follow a guide wire (not shown in this figure). The guide arm 38 is connected to a series of mechanical linkages and in turn connected to suitable sensors such as potentiometers to gauge any deviation from the desired path of travel. The potentiometers are protected from exposure to the elements by an enclosed box 40 ar d the potentiometer measured values are sent to a controller unit 42 for processing. Thc: controller also has the ability to receive information remo tely via an antenna 44.

Electrical power is supplied to the tower 12 either from a generator located onI the tower, a remote generator, or from mains power.The tower is adapted to receive this power and distribute it to the various components requiring electricity on the connected irrigation spans via a distributor 46. The supplied power is typically 3phase; however the device, 10 could be adapted to receive single phase power.

Figure 3 shows a front view of the connection between a first irrigation span 14 and a second irrigation span 16. The second irrigation span is supported by a tower SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THU 15:38 FAX 61 8 82119433Lei rPeln l04 Lesicar Perrin [a 024 l0 No structure 48, whereby, a pair of wheels 50, an electric moror 52 and a gearbox 0 assembly 54 (for each wheel) is attached thereto. The connection an-angement shown ini this figure, between the first and second irrigation spans, is the same for all 0 connected irrigation spans. This includes a means of connecting the overhead water conduit 36 of one irrigation span with another, an assemibly for maintaining the Cl desired movement on the spans, and an assembly for the movement of each span.

Also shown is a sprinkler head 56 adapted to release a predetermined amount of waler V) over the field being irrigated. The sprinkler head 56 is connected via a pipe to the ras3 Nl en of the overhead water conduit 36. This connection 58 allows for dirt and debris to settle at the: base of the overhead conduit 36 and not be passed into the sprinler head

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N 56, reducing maintenance and allowing for the sprinkler to distribute a mare o consistent amount of water.

Figur 4 shows a closer perspective view of the connection between irrigationi spans 14 and 16 and the guidance mechanism used to coordinate the movement of the connected in-igation spans. The overhead water conduit of a first irrigation span is supported by the addition of cross bracing 60 and terminates in a connection arrangement 62. This connection arrangement includes a flexible pipe 64, allowing for movement between the two irrigation spans, and a bracket, supporting the flexibI'a pipe 62, conniecting che overhead water conduits of the two irrigadtion spans. Mounted perpendicularly on the bracket 66 is an extension arm 68 with a mechanical linkage connected perpendicularly. This linkage 70 is spring tensioned to maintain a constant bias on the potentiometer located in the box 72, mounted on the second irrigation span 16. Any movement of the first irrigation span, relative to the second irrigation span, is minrried by the movement of the linkage 70 and changes the strokf.

length of the attached potentiometer accordingly.

Information regarding the alignment of the two irrigation spans, rate of relative movement and speed of travel of the connected irrigation spans is measured as movement of the potentiometer stroke length and a signal is sent to the controller zas to the status of the irrigation spans. This information is then used to determine whether the speed of the second irrigation span needs to be increased or decreased in order to maintain alignmnt The controller monitors the position of all connected irrigation spans through their potentiometer readings and if one span requires a COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THT 15:36 FAX 61 8 82119433 LscrPri 2 LesIcar Perrin [a 025 change of speed, this will be reflected in a change of speed of all other spans required c-I to maintain the linear motion of the irrigation device Figure 5 shows thle guidance arrangement for the irrigation device Attached to the itiigation device tower 12 is a guidance system adapted to guide the tower and subsequently the connected irrigation spans in the desired direction. This systemn comprises, a forward and rear guide arm 38, adapted to follow a guide wire 74.

V) ~The forward and mnar guide arms 38 can be used to guide the irrigation device 10 in both directions and includes a wheel 76 to engage the guide wire 74 at its extremity.

The wheels 76 are V shaped so to receive the guide wire 74 in the V shaped groove, thus preventing the possibility of the guide arm 38 disengaging from the guide wire o 74 and no longer directing the movement of the device 10. Also preventing the 0 disengagement of the guide arms 38 from the guide wire 74 is the weight of the guide arins The arms 38 are pivotably connected to a guidance system frame 78 with vertical pivot points 80. This ensures that the weight of the arms 38 provides sufficient tension to retain the wheels 76 on the wire 74 and ensures their consisrern..

movement- The device 10 may also include monitoring devices adapted to monitor the movement of the wheels 76 further ensuring that the device l0 is moving in the desired direction dictated by the guide wire 74.

T'he guide wire 74 is installed on the land being irrigated in order to determine; the desired path of travel for the device 10 so that it irrigates the maximum surface area of land. The wire is strung between posts fixed to the ground at regular intervals and at a predetermined height and tension. The height of the wire is determined by the contours of the land and its use, such as whether the land is used for livestock grazing or rasing crops.

The guide anus 38 pivot in the horizontal plane at pivot points 82. This horizontal movement of the guide antis 38, following the guide wire 74, is transferred horizontally to horizontal linkages 84 and transferred again to the forward and rear potentiometer linkages, 86 and 88 respectively. The stroke of the forward and rear potentiometers, 90 and 92, moves in and out according to the movement of the forward and rear potentiometer linkages 86 and 88. If the forward guide arm moves inwards, relative to the guide wire 74, the forward potentiometer linkage 86 also moves inwards shortening the forward potentiometer's stroke length 90. Simi Iarly, if COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THU 15:36 FAX 61 8 82119433 Lescar Perrin S026 12 o the forward guide arm moves outwards, the forward potentiometer's stroke length 0i is lengthened. The movement of the stroke length of the potentiometers is measured and the exact position of the irrigation device tower 12, relative to the guide wire 74, z is known, so as to direct the controller to alter the speed of the left or right wheels to maintain the desired motion.

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Figure 6 shows a top view of the potentiometer box 40 with forward and rear V' potentiometers 90 and 92. It can be seen more clearly, in this figure, that the stroke of Cl the potentiometers are lengthened or shortened by the rotation of the forward and rear linkage connections, 94 and 96, with their respective potentiometers. Information IC regarding the stroke of the potentiometers and the rate of movement is collated at the IoN junction point 98 and forwarded to the relevant controller circuitry.

Cl Figure 7 shows a top view of the irrigation span connection potentiometer box 72 with a single potentiometer 100. Only one potentiometer is required to measure accurately the movement between connected irrigation spans. The stroke of the potentiometer is dictated by the movement between the irrigation spans and transferred through the mechanical linkage connection 102. Data regarding the stroke length of the potentiometer 100 and the rate of change in the stroke length is collected at the junction point 104 and sent to the controller circuitry.

Figure 8 shows a side view of the driving mechanism of an irrigation span, mounted on a frame 48, including an electric motor 52, used to supply power to rotate the wheels 50. The motor is controlled by a variable frequency drive unit located in the controller box 42. The accurate control capabilities of a variable frequency drive unit allow for the fine adjustment of electric motor 52 speed. Thus, a high level control of motion, dictated by the stroke of the potentiometer, can be achieved. The electric motor can be accelerated or decelerated to stay within the desired range of potentiometer stroke length. Similarly, electric motors 26 are controlled by a variable frequency drive unit and the movement of the irrigation tower 12 can be accurately controlled.

The control unit also has the ability to measure the rate of movement in the potentiometers and can calculate the additional time delay required for the attached irrigation span to accelerate/decelerate to the correct speed in order to maintain the COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THUL 15:37 FAX 61 8 82119433 LscrPri 2 LesIcar Perrin IR1027 13 VaO o desired range of potentiometer travel- This time delay further ensures that the angle 0 between connected irrigation spans is within the desired range and as close as possible to being constant, as the irrigation device 10 travels through the field- This ability also z enables the irrigation device 10 to maintain the desired angle between connected irrigation spans whilst travelling in centre pivot mode and can compensate for the last Cl connected irrigation span movinig faster than the irrigation spans closer to the stationary irrigation tower 12.

Figure 9 shows a reduction gear box 54 for each wheel 50 on each irrigation span- The gearbox is adapted to receive a rotating shaft rowaed by the electric motor 52 and transfer this energy to the wheels 50. Sufficient torque must be employed to No overcome inconsistent terrain over the field being irrigated. Wheels 50 are also fitted o with tyres adapted to suit the varying terrain. The. driving mechanism arrangement of an electric motor and gearbox assembly is replicated on eaeb side of the irrigation tower 12, with electric motor 26 and gearbox 24 operating in the samne fashion to wheels 28 as the gearbox 54 and motor 52 shown in figure 8 and 9.

Figure 10 shows a first panel 106 located in the controller unit 42, mounted cn the irrigation tower 12. The first panel 106 contains the user accessed monitoring equipment, switches and programmable controls. A main on/off switch 108 is located on this first panel 106 to isolate the circuit board. Switch bank 110 contains a switch to power the programmable controller 1 1Z, and switches to change the driving modes of the irrigation device 10. The programmable controller 112 allows the irrigation device to be set up according to the characteristics of the field being irrigated with variables such as speed of travel and water output configurable to optimise the irrigation of the expanse of land and ensure automation. The first panel 1-6 also contains monitoring equipment such as the voltmeter 114 and the trip counter 1116.

The programmable controller 112 also contains a read out display adapted to display information regarding the status of the device Figure I11 shows a second panel 1 18, located behind the first panel 106, in thet controller unit 42. The first panel 106 is mounted onto the controller unit 42 with one side of the panel having a hinge, allowing for the rotation of the panel outwards revealing the fixed second panel 118 containing the hardware necessary to operate the device 10- Located on the second panel 118 are the wiring connections, switches and COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THIT 15:37 FAX 61 8 82119433 Lesicar Perrin 121028 14 O relays 124, telecommunications equipment 122 and variable frequency drive units o120. The telecommunications equipment 122 allows for remote monitoring and control of the device 0 Z The variable frequency drive units 120 allow for a more efficient, low en 5 maintenance and more accurate controlling mechanism, with the ability to reverse the connected electric motors. These drive units provide the device 10 with the ability tc tightly control the speed of the electric motors on the irrigation tower 12 and the C'l connected irrigation spans 14, 16, 18 and other irrigation spans not shown. The finer electric motor control ensures that the irrigation device 10 traverses the field in its ci 10 desired path. A variable frequency drive unit may also be fitted to a pump unit, Nadapted to be located on the irrigation tower to pump water from a canal. As the field o being irrigated may require different water output levels during the irrigation and the water canal may have different depths, a pump with a high level of control is advantageous.

Further advantages and improvements may very well be made to the present invention without deviating from its scope- Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", Le. the features specified may be associated with further features in various embodiments of the invention.

Dated this 23 November 2006 COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23

Claims (11)

1. 4. An irrigation device as in claims 1 -3 wherein said irrigation tower includes a guidance mechanism including a sensing means and at least one mechanical linkage adapted to support at least one guide arm, whereby said guide arm is adapted to follow a guide forming the predetermined path. 5, An irrigation device as in claim 4 wherein said guide is a wire extending the length of the predeterminied path and fixed at a predetermined height above a field.
2. 6. An irrigation device as in any of the preceding claims wherein said guide aim is adapted to move horizontally above the field and said horizontal movemnent is transposed through at least one said mechanical linkage into a change in the. potentiometer stroke length of the sensing means whereby said stroke length is analysed by the controller and adapted for use in maintaining the substantially parallel movement of the irrigation tower relative to said guide.
3. 7. An irrigation device as in any of the preceding claims wherein said guide arm is adapted to receive said guide with a grooved rotating wheel located on the extremity of said guide arm. COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '06 THUL 15:38 FAX 61 8 82119433 LscrPri 3 LesIcar Perrin Z030 16 No 8. An irrigation device as in claims 1 -3 wherein at least one said irrigation span o is coupled to said irrigation tower and additional said irrigation spans are connected to the previously connected irrigation spans in a series arrangeme:nt z whereby said connected irrigation spans include a connection mechanism at one of end of said irrigation spans whereby said connection mechanism titer Cl includes sad sensing means.
4. 9. An irrigation device as in claims 1 3 and 8 wherein said connection Cl mechanism is further adapted to ensure the movement of said connected irrigation spans along the predetermined path by at least one mechanical linkage adapted to transpose relative movement between said connected No irrigation spans into a change in the potentiometer stroke length of the sensing o means whereby said stroke length is measured, sent to a controller, and compared with a desired potentiometer stroke length range whereby said controller sends a signal to alter the speed of said driving means accordingly thus maintaining the substantially linear movement of the irrigation span relative to said adjacent irrigation span. An irrigation device as in any of the preceding claim wherein said irrigation tower includes a pivotable connection between said irrigation tower and tbe first irrigation span wbereby said plurality of connected irrigation spans are adapted to be rotated about the irrigation tower.
5. 11. An irrigation device as in claims 1 and 2 wherein said irrigation tower incluL's two independently operated said driving means adapted to move in both forward and rearward directions and in both a pivotal or linear manner.
6. 12. An irrigation device as in claim 11 wherein said independent driving means further include an electric motor connected to a pair of wheels via a gearbox.
7. 13. An irrigation device as in claim 12 wherein said wheels are adapted to iraverie all terrains.
8. 14. An irrigation device as in any of the preceding claims wherein said controller monitors the potentiometer stroke length of all the irrigation device potentiometers and said controller compares the measured potentiometer COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23 23/11 '00 THU 15:38 FAX 61 8 82119433Leca Printl3 Lesicar Perrin Q031 17 VaO o stroke length with the desired range of potentiometer stroke length whereby if 0 the measured stroke length deviates from the desired operating stroke length range said corresponding electric motors are adapted to alter their speed so as 0 to return the potentiometer stroke length back to the desired range.
9. 15. An irrigation device as in claim 1 and 2 wherein said irrigation tower further includes a water intake point and a power intake point far distribution throughout the irrigation device. An irrigation device as in any one of the preceding claims wherein said '4 connection mechanism between said irrigation spans further includes a flexible conduit adapted to connect a water bearing conduit located on one said o irrigation span with another water bearing conduit on the adacent irrigation Cl span.
10. 17. An itrigation device as in any one of the preceding claims wherein said water bea-ring conduit includes a plurality of vertically mounted connections adaptMd to transmit water to a plurality of sprinkler heads adapted to release water a fixed rate.
11. 18. An irrigation device as in any one of the preceding claims wherein said controller includes at least one variable frequency drive unit for the control of said electric motors. COMS ID No: SBMI-05450615 Received by IP Australia: Time 16:15 Date 2006-11-23