GB2050786A - Irrigation boom structure - Google Patents

Abstract

A boom, truss or the like structure comprises extruded members having a section which includes means defining a fluid-tight conduit 1 and which defines means which provides at least one longitudinal extending fin 2. The structure can be assembled from a plurality of such extruded members with bracing members 4 being fixed to respective fins. Such a boom as can be created with such a structure is useful for irrigation apparatus as the boom structure preferably lends itself to water ducting along the boom to outlet ports disposed therealong. <IMAGE>

Description

SPECIFICATION A boom structure The present invention relates to the provision of a boom, truss or the like structure using as the longitudinal members of such a structure a plurality of extruded members each of which has a section which includes means defining a fluid-tight conduit and integral means which provides at least one longitudinally extending fin. The invention also consists of the use of such structures in irrigation apparatus.

Many space structures have been devised which make optimum use of materials for a given strength requirement, for example, geodesic domes. In the field however of trusses, booms and the like there is still room for considerable improvement especially where such a boom has to be reasonably light, cheap and easy to erect and disassemble and is to carry a liquid, for example, irrigation water therealong. In the province of low pressure irrigation where large carriage mounted boom structures are used there is considerably scope for improvement whereby if an improved boom can be deviced greater widths of irrigating run can occur especially when using, for example, a boom dispersed to either side of such a carriage.

Many forms of boom, truss or the like type irrigators are known which use a rigid boom structure which is mounted from a single carriage or a plurality of carriages. Such prior art constructions include those disclosed in New Zealand Patent Specification Nos 145,566, 177,046 and 182,985.

None of these structures however, employs the use of a boom structure which allows for the economical manufacture of a single or even multiple carriage supported boom structures which are sufficiently strong with respect to their weight to allow for spans larger than those normally encountered. None of the structures for example discloses a cheap modular type structure which can be readily fabricated by a farmer or the like, upon delivery from relatively cheap components yet will provide an overall span from one side to the other side of a carriage unit of for example 70 to 100 metres. It is therefore an object of the present invention to provide means and or methods which will go at least some way to the provision of such a boom, truss or the like structure and or irrigation apparatus employing such structures and the use thereof.

In one aspect the present invention consists in a boom, truss or the like structure which includes a plurality of mutually spaced but substantially parallel extruded members each having a section which includes means defining a fluid-tight conduit and integral means which provides at least one longitudinally extending fin, and which has bracing members between said extruded members, each of which bracing members is anchored at each end by appropriate fixing means to a longitudinally extending fin of an extruded member, the bracing members holding said plurality of extruded members in a mutually fixed relationship with respect to the transverse axes thereof.

Preferably said boom, truss or the like structure is a boom and comprises two or three extruded members. In the case of a boom of three extruded members preferably each includes two longitudinally extending fins appropriately angled (for example 60 apart) so that bracing members from a fin of a particular extruded member can extend to a fin of one of the other extruded members and from the other fin of said particular extruded member to the other of the extruded members so that a triangular arrangement transverse to the extent of said boom results. Ideally the boom forms part of irrigation apparatus and at least one of said extruded members has the fluid-tight conduit thereof adapted in use to carry water to discharge ports or nozzles spread along the length thereof.

In the preferred form of the present invention each of said extruded members is connected by bracing members to the remaining two members and said bracing members between any two extruded members define a zig-zag arrangement along and between any two extruded members. As used herein and in the appended claims the term "substantially parallel" encompasses elongate members that extend alongside each other but which if extended for enough may converge together.

In a further aspect the present invention consists in a method of construction which involves the use of an extruded member substantially of a kind as used in a boom, truss or the like structure in accordance with the present invention or substantially as hereinafter described and the bolting or other fixing of bracing members between extrusions to be joined together by such bracing members to form said boom, the bolting or other fixing being through appropriate apertures in the longitudinally extending fins of each extruded member to thereby create a said boom, truss or the like structure.

In a further aspect the present invention consists in irrigation apparatus which includes carriage means and a boom or portion thereof extendable to either side of said carriage means having regard to the direction of travel thereof, said boom or portion thereof being a structure in accordance with the present invention, the structure bein further characterised in that water dispensing ports or nozzles are disposed along the length of one of said extruded members on either side of said carriage means to allow the ducting of irrigating water there into and from thence out of said discharging ports or nozzles as said carriage advances in use.

Preferably there is a distinct boom disposed to each side of said carriage means and each boom includes an inner portion which is formed from three extruded members braced together by bracing means in a substantiallytriangularform with two of said extruded members lying substantially at the same level to define the bottom two extremities of said triangular form, and the outer region of said boom being formed from two extruded members only which are braced to each other and each of which is in communication in a fluid-tight manner with one of the lower extruded members of the triangular form region of said boom, there being discharge Dorts or nozzles from the fluid-tioht con duits ofthose communicating extruded members arranged to receive and dispense irrigation water.

Preferably the inner extremity of each said boom is pivoted by trunnion means to said carriage and is capable of being pivoted upwards or downwards relative thereto for adjustment purposes. Preferably outer regions of said boom are supported at least in part from inner regions of said boom or from the carriage itself by cable means.

Preferably the two booms are movable simultaneously about a central substantially vertical pivot from said carriage means so that the same can be moved from their flanking position during which they are normally used for irrigation purposes to align with the direction of travel of said carriage means for towing purposes. Preferably said carriage means includes means to follow a cable and thus guide the advance movement of said carriage means in use while trailing a hose which is in communication with the fluid-tight conduits of those extruded members arranged to receive and dispense water and a source of such water.

Preferred forms of the present invention will now be described with reference to the accompanying drawings in which Figure 1 is the preferred extrusion section for irrigating apparatus, the section including a tubular conduit from which at a mutual angle of 60 two fixing fins extend, the fixing fins including a strenghtening flange at the distal end thereof, Figure 2 shows a single finned variation, Figure 3 shows a double finned variation.

Figure 4 shows a further double finned variation but one where the fins are mutuallys spaced by 90 , Figure 5 is a variation of the section as shown in Figure 4, the variation being the inclusion of a third fin spaced between the others, the third fin being suitable for fixing the ends of, for example, a diagonal brace in a four longitudinal member structure, Figure 6a shows diametrically how a section such as that shown in Figure 2 can have the fins thereof directed towards each other and bracing members can be zig-zagged or otherwise extended therebetween and fixed thereto by appropriate fixing means preferably nut and bolt, Figure 6b is a variation of the arrangement shown in Figure 6a in that one section is spaced above the other, Figure 7 is a front elevation of a preferred form of irrigation apparatus in accordance with the present invention showing the carriage means with its steerable front dual wheels and its trailing more widely spaced rear wheels and its central pedestal support for the two booms which extend outwardly on either side of the carriage means, each boom comprising a first region which is substantially triangular in form through there being three extruded members substantially of a section as shown in Figure 1 and showing one and a half further modules but of a dual extruded member construction the fluid-tight conduits of which are in a fluid-tight communication with the longer two conduits of the triangular inner region and in turn in a fluid communication with the central pedestal of said carriage means, the Figure also showing cable or the like means extending from the apex of the outer regions of the triangular section so as to support the distal regions of the boom, Figure 8 is a view AA with respect to Figure 7 showing the triangular form of the inner region of a boom and showing how the same can bear a rotatable connection having the lower two extruded members thereof in fluid-tight communication with the central pedestal which receives water via a turbine which drives a cable winch which in use advances the carriage means, which turbine receives pressurised water from behind the unit via a hose connection, Figure 9 shows a triangular relationship between lengths of section as shown in Figure 2, Figure 10 is a diagrammatic view showing the mutual disposition of sections as shown in Figure 4 for a boom of square section, Figure ii is a variation on the configuration of Figure 9 in that it includes the sections of Figure 5 which facilitate the provision of diagonal braces, and Figure 12 is a diagrammatic plan view of a rectangular paddock showing how apparatus in accordance with for example Figures 7 and 8 would preferably be used, the mode of operation also using a hose loop carriage means in accordance with the invention as described and claimed in New Zealand Patent Specification No. 192,380.

In the preferred form of the present invention the boom may have two, three or four longitudinally extending members. In each case however it is a feature of the invention that the section bean extruded section preferably for example of a light weight metal such as aluminium or alloy thereof and at the same have the required number of fixing fins extending from the means defining the conduit for maximum strength, maximum conduit capacity etc.

for a given weight of material. Preferably the conduit is bounded by an annulus portion and the flanges extend therefrom. Figures 2 to 5 show suitable variations. Figure 1 however shows for a three longitudinal member boom which is preferred for irrigation purposes the two flanges having outwardly directed strenghtening flanges which will rigidify the whole structure. With the arrangement as shown in Figure 1 preferably the bracing members would be fixed to each flange on that side to which the strenghening flange is not directed. There would still be ample room for a person to have access to the nut and bolt with a spanner notwithstanding the provision of the small strengthening flange.

In the preferred form of the present invention the boom structure is one of two of which would be pivotally mounted about a horizontal pivot to a carriage of movable irrigation equipment, for example, a self winching carriage capable of following for example a wire, hose or the like as water is being passed down through preferably one of the conduit means of the longitudinally extending members. In this way therefore weight is reduced in that no additional conduit to those embodied in the boom structure are required.With structure, in accordance with the present invention, it is envisaged that simple extruded pipe, for example, holed or flat tended and holed at each end could be used as the zig-zag bracing members which allows on site erection of a strong yet long boom using simple tools for example, a spanner thus ensuring that with only two sections being required transporting costs of an unassembled boom will be minimal. In other forms the bracing members could be appropriate angle, channel or box sections.

A preferred form of the present invention is disclosed in Figures 7 and 8 which utilize a section as shown in Figure 1. The section as shown in Figure 1 it can be seen consists essentially of a tube-like portion 1 having two flanges which extend longitu dinallytherealong for coupling on their inner facing faces to the appropriate bracing members. These flanges 2 include at their outer end strengthening flanges 3 which preferably turn outwards and thus away from the face against which the bracing members are designed to bear in use. A person skilled in the art inspecting therefore Figures 7,8 and 9 will appreciate how a trinagularform of truss held by a zig-zag series of braces 4 can be formed, the braces in the preferred form of the present invention being bolted to the appropriate flanges.In other forms however, the same could be welded or riveted.

In the structure as shown in Figure 7 the triangular form would have the lower two extruded members thereof mounted by appropriate horizontal trunnion means to a carrier portion 5 which is rotatably mounted from the central pedestal 6 of the carriage means 8. The central pedestal 6 carries water from the driving turbine 9 which through an appropriate mechanical drive, drives a winch 10 which in use will draw the carriage means 8 along a laid out and anchored cable which is received through an eye 11 of the draw bar 12. The water to power the turbine 9 is via a drag hose which is engaged behind the rear wheel to the hose receiving conduit 13.A person skilled in the art will appreciate how simple with such an arrangement it is to duct water via the central pedestal 16 to both of the lower two fluidtight zones of the lower most extruded members of the triangular booms so that the same can issue as required through appropriate irrigating port or nozzles.

To extend the scope of the irrigated area to be irrigated by a single pass of the apparatus outer regions 14 are provided which are cable supported (denoted by reference numeral 15) and further half sections 16. The regions 14 and 16 are preferably of the same section which constitutes the lower two sections of the triangular region and are of course each in a liquid ducting communication therewith.

Ideally each of the lower two sections throughout the full length of each boom is provided with spaced irrigating nozzles which preferably are directed horizontally or downwardly in some instances.

The operation of the preferred apparatus will now be described in detail. With a preferred form of the present invention a water pressure of only 69 kPa (10 psi) at the nozzles will be employed while effectively distributing up to 2,300 litres per minute (500 GPM).

The effective wetted strip covered by such a preferred form of the present invention is 70 metres (230 feet) and a single operator will be capable of handling with a minimum of shifting time the operation of the apparatus thus meaning an irrigation capability of 630 hectare - centimetres based on a three week cycle. Application rates can be provided from 2 cms per hour and upwards depending on soil uptake crop and slope. Also, while the unit shown in Figures 7 and 8 is designed to span 58 metres for a 70 metre wetted strip alternative forms can be devised preferably with a higher central pedestal so that cable guys can be extended therefrom for distal support of a much greater span.With the arrangement as shown in Figure 7, however, it can be seen that the maximum effect of any wind on the unit is minimized owing to the low wind profile at the outer reaches of the boom at which portions of course the greatertorque would be exerted on the central pedestal.

While the actual water supply to the distribution equipment in accordance with the present invention represents only a part of the total energy input to an irrigation scheme the possible very significant reduction in operating pressure coupled with better water control from the nozzles to reduce atmospheric loss and wind interference can create dramatic savings in running costs. Energy input savings of up to at least 70% are possible using a low pressure irrigation system in accordance with the present invention rather than a high pressure spray system.

Another feature that is of importance is the hose support which is disclosed and claimed in New Zealand Patent Specification No. 192,380, full details of which are hereby herein incorporated by way of reference.

The irrigation apparatus in accordance with the present invention has a main chassis constructed from steel channel and hollow steel sections. The sub-chassis containing the power unit comprising turbine, valving controls and geared winch unit would be bolted onto the main chassis. The front wheels which are steerable with respect to the more widely spaced rear wheels are kept close together in order to reduce deviation effects of uneven ground and to enhance the travel straightness of the machine. A hand operated parking brake would be fitted as standard to enable the braking of the machine against movement under the action of for example wind gusts when not operating. Also, it is desirable that a tension released brake system be used so that when a run downhill is encountered the machine does not run ahead of the winching action.

The design of the boom previously defined provides maximum strength for material weight while maintaining an adequate cross-section of water-way thereby reducing friction loses. Jig cutting, drilling and positioning ensures uniformity and compliance with assembly tolerances thus making the whole modular construction easy to assemble, firstly into two and a half 11 metre modules and then together to define the boom or half boom on either side of the carriage means. In order to provide an adjustment of the level of each half boom or boom turn-buckles at the top of the central pedestal would be provided. In the preferred form of the present invention short hoses from outlets in the column to all bottom members of the boom sections could be provided from the water carrying rotary sealed pedestal.

Preferably each water carrying member would be fitted with a flushing plug at the end.

The boom would preferably be supported on a 200 millimetre diametre rugged tube water supply and structural pedestal or column. The lower end of the column would rest in a bearing incorporating a water lip seal. The tower which is bolted together in panel sections carries an upper bearing thereby allowing the boom to be rotated when desired e.g.

for transport. The top of the tower carries a turret structure with fittings to receive the two boom halves as previously described.

in order that one operator can transport, manoeuvre and shift the unit a method of rotating the boom is incorporated and this preferably consists of a 12 volt D.C. geared electric motor and further chain reduction drive to the boom turret.

To enable irrigation to be carried out adjacent to a road boundary a boom lock would preferably be provided to ensure that a high wind gust does not rotate the boom overthe roadway.

Nozzles would be spaced along each bottom water bearing tube of the boom at 0.375 metre intervals and face forward and/or to the rear. The nozzles would thus give a fan form of overlapping discharge.

To ensure however that the irrigation is only to the rear of the irrigator in the wheel path two short central pipes carry nozzles which can be valved on or off according to direction of travel. It is consequently not necessary to rotate the boom when on subsequent run travelling back down a field (i.e. just the carriage). End nozzles would be provided to give additional coverage. To minimize wind effects nozzle angles are kept low so that in standard construction water is projected almost horizontally. While direct wind loss and interference would be reduced even more by directing water further downward it would have the effect of increasing the precipitation.

The combined efficiency of a turbine and speed reduction gearing would be such that a tractive force in excess of 4,000 kg would be achieved.

The main supply pipe on the irrigator would be fitted with a disc shut-off valve which is under the control of a generously proportioned servo hydraulic cylindar. An adjustable stop is fitted to the tension cable and when the machine carriage reaches the stop a pilot hydraulic valve would be operated and would admit main pressure to the servo cylinder which shuts water off from the turbine.

Under high wind conditions the boom rotational control may be over-ridden. A cam on the centre feed column would be set to operate a pilot valve at approximately 30 deviation and so cause the main servo valve to close thus shutting the machine down. If winds intensify the boom can rotate further to align its axis with the wind direction.

A specially hydraulically actuated release locks the winch drum reaction lever as soon as water pressure builds up at the machine. This device allows the rope to be pulled freely from the drum for setting up for a run but saves the operator returning to the machine to set it in operation when water is turned on at the hydrant. A friction spring-loaded brake would be also provided in order to prevent cable over-run.

Speed control of the unit would be provided by a stepped belt drive arrangement. A high tensile cable would be used forthe guiding and pulling purposes and would be engaged with appropriate ground anchors.

For the purpose of winding in the drag hose a hose transporter with a drivable reel preferably from the PTO of the tractor would be provided so that a hose could be laid out or taken in as desired. The present invention is designed for lie flat 100 millitmetre to 125 millimetre hoses but of course is readily adaptable to other sizes and indeed other than lie flat type hoses.

Other safety devices would be provided such as liquid flow filters, safety earthing chains, etcetera.

The standard length of hose that would be provided would be about 200 metres and depending on the discharge capacity for which the machine was required hoses would be e.g. 100, 105 or 115 millimetres in diameter.

In order also to minimize wear on the drag hose the loop thereof would be lifted clear of the ground by the means disclosed and claimed in New Zealand Patent Specification No. 192,380.

To operate the unit therefore and in this connection reference is made to Figure 12 of the accompanying drawings the following sequence of events would be followed. Firstly, the equipment would be towed by a tractor with the hose transport carriage and boom and then the hose loop carrier or transfer wheel of New Zealand Patent Specification No.

192,380. The apparatus would be taken to a condition as shown in Figure 12 at region A where the loop of the hose 17 is supported by a transfer wheel 18 which will advance with the loop as the apparatus 19 in accordance with the present invention advances. Forthe purposes of simplicity the boom itself is not shown but only an arrow which denotes the forward advance direction of the carriage of the apparatus when in use, the extent of the irrigating area being the extent of the strips three of which are shown in Figure 12.

As a next step the hose transport arrangement 20 would be towed by the tractor 21 simultaneously with the cable along which the apparatus 19 will winch itself in the general direction along which the apparatus 19 is to operate. The tractor 21 would take the hose to a first hydrant 22 where the hose would be connected. The tractor would then continue on to an anchor 23 where the cable would be anchored. At that stage the tractor would return to the hydrant 22 where upon water pressure would be actuated and irrigation would commence with the irrigation apparatus 19 advancing by a winching action along the cable until such time the same stops just si of the ground anchor e.g. at or about C. At this stag the hose transfer wheel 18 is at its position as denoted by reference No.24. At that stage a slightly modified reverse and repeat procedure would commence and the arrangement would be continued until all three lanes had received their required water dosage.

It will be seen with the three forms of apparatus all being capable of towed together etcetera that the man-hours involved in setting the apparatus for a many hour pass over the length of a prepared area of ground is minimized.

From the foregoing then it can be seen that the present invention provides a method of constructing a nozzled or other ported boom like arrangement that has particular application in irrigating systems or effluent disposal with low aeration in that it allows light weight yet strong large span structures to be made which have the consequent advantages of ease of operation, low man hours and low energy requirements. It is believed therefore that the means and methods of the present invention will find widespread application in boom, truss or the like structure construction and in particular although not solely irrigation.

Claims (13)

1. Aboom,trussorthe like structure which includes a plurality of mutually spaced but substantially parallel extruded members each having a section which includes means defining a fluid-tight conduit and integral means which provides at least one longitudinally extending fin, and which has bracing members between said extruded members, each of which bracing members is anchored at each end by appropriate fixing means to a longitudinally extending fin of an extruded member, the bracing member holding said plurality of extruded members in a mutually fixed relationship with respect to the transverse axes thereof.

2. A boom, truss or the like structure as claimed in claim 1 wherein said structure is a boom comprising two extruded members only.

3. A boom, truss or the like structure as claimed in claim 1 wherein said structure is a boom and there are three extruded members each of which includes two longitudinally extending fins appropriately angled so that bracing members from a fin of a particular extruded member can extend to a fin of one of the other extruded members and from the other fin of said particular extruded member to the other of the extruded members so that a triangular arrangement transverse to the extent of said boom results.

4. A boom as claimed in claim 3 wherein each of said three extruded members is connected by bracing members to the remaining two extruded members, and said bracing members between any two extruded members define a zig-zag arrangement along and between said any two extruded members.

5. A boom, truss or the like structure as claimed in any one of the preceding claims wherein the same forms part of irrigation apparatus and at least one of said extruded members has the fluid-tight conduit thereof adapted to use to carry water to discharge ports or nozzles along the length thereof.

6. A boom, truss or the like structure as claimed in any one of the preceding claims substantially as hereinbefore described with reference to any one, some or all of the accompanying drawings.

7. A method of construction which involves the use of an extruded member substantially of a kind as harninhofnrn hn m rlncrihrl nrl thp hnltinn nf hr::xrinn members between extrusions to be joined together by such bracing members to form a boom, the bolting of being through appropriate apertures in the longitudinal extending fins of each extruded member to thereby create a boom, truss or the like structure as claimed in any one of the preceding claims.

8. Irrigation apparatus which includes carriage means, and a boom or portion thereof extendable to either side of said carriage means having regard to the direction of travel thereof, said boom or portion thereof being a structure as claimed in any one of claims 1 to 6, the structure being further characterised in that water dispensing ports or nozzles are disposed along the length of at least one of said extruded members on either side of said carriage means and any such extruded member is provided with means to allow the ducting of irrigating water there into and from thence out of said discharging ports or nozzles as said carriage advances in use.

9. Irrigation apparatus as claimed in claim 8 wherein there is a distinct boom disposed to each side of said carriage means and each boom includes an inner portion which is formed from three extruded members braced together by bracing means in a substantially triangular form with two of said extruded members lying substantially at the same level to define the bottom two extremities of said triangularform, and the outer region of said boom being formed from two extruded members only which are braced to each other and each of which is in communication in a fluid-tight manner with one of the lower extruded members of the triangular form region of said boom, there being discharge ports or nozzles from the fluid-tight conduits of those communicating extruded members arranged to receive and dispense irrigation water.

10. Irrigation apparatus as claimed in claim 9 wherein the inner extremity of each of each said boom is pivoted by trunnion means to said carriage and is capable of being pivoted upwards or downwards relative thereto for adjustment purposes.

11. Irrigation apparatus as claimed in any one of claims 8 to 10 wherein outer regions of said boom are supported at least in part from inner regions of said boom or from the carriage itself by cable means.

12. Irrigation apparatus as claimed in any one of the preceding claims wherein the two booms are movable simultaneously about a central substantially vertical pivot from said carriage means so that the same can be moved from their flanking condition during which they are normally used for irrigation purposes to align with the direction of travel of said carriage meansfortowing purposes.

13. Irrigation apparatus as claimed in any one of claims 8 to 12 wherein said carriage means includes means to follow a cable and thus guide the advance movement of said carriage means in use while trailing a hose which is in communication with the fluid-tight conduits of those extruded members arranged to receive and dispense water and a source of such water.

Id Irrinntinn annaratus as claimed in anv one of claims 8 to 13 substantially as hereinbefore described with reference to any one, some or all of the accompanying drawings.