GB2230506A - Apparatus for collecting aquatic vegetation - Google Patents

Abstract

Apparatus for collecting aquatic vegetation comprising a boat (10), a collecting conveyor (15) pivotally mounted at the bow of the boat and having a cutter (17) at its remote end. Inside the boat is a slatted storage conveyor (22, 23). The boat may be driven over the surface of an island waterway with the cutter (17) and the lower part of the collecting conveyor (15) submerged. Weeds are cut and carried upwardly into the boat by means of the wire mesh conveying surface (16) of conveyor (15) and the storage conveyor is driven incrementally towards the stern until a full payload of vegetation is taken on board, whereupon the boat may be moved to the bank with collecting conveyor (15) pivotted to an upwardly inclined position above the bow of the boat. Vegetation may then be off loaded onto the bank by driving the storage and collecting conveyors in the reverse direction. <IMAGE>

Description

APPARATUS FOR COLLECTING AQUATIC VEGETATION THIS INVENTION relates to apparatus for collecting aquatic vegetation. The management of inland waters such as lakes, rivers, canals, reservoirs and the like requires that the growth of aquatic vegetation or weed be controlled. The weeds including filamentous algae may be submerged below the surface, floating on the surface or emerging from the surface close to the surrounding land.

In all cases it is highly desirable that the weed be harvested and removed from the water.

Manual methods of control are labour intensive and thus expensive, and are often impractical in the case of larger bodies of water.

Various chemical treatments are known but these also are expensive and in many cases unacceptable in contaminating the water which is then unsuitable for domestic use or for irrigation. In cases where the weed growth is dense, chemical treatment is limited to small areas thus to avoid excessive deoxygenation of the water and consequent risk of fish mortality.

Other methods of weed control, for example by the introduction of herbivorous fish, usually effect only partial control.

Various mechanical devices are used to control aquatic weeds, some operating from the adjoining land and others on the water. Those which operate on the water are generally of two types, i.e. those which first cut the weed and later collect it in separate operations, and those which cut and collect the weed in a single operation.

The present invention concerns apparatus for use in cutting and collecting aquatic vegetation in a single operation, embodying the following important and novel features which significantly improve the effectiveness of a machine of this type: a) the apparatus combines the advantages of a fully mechanised machine which requires only one operator with an easily transported and manoeuvred apparatus in which the safe payload is high when compared with the total weight of the apparatus; b) the simplicity of the apparatus reduces the number of working parts and thus simplifies construction and maintenance; c) the apparatus may be navigated under low bridges as its height above the water is relatively small; d) the apparatus may be used additionally as a work boat for other operations such as herbicide distribution.The conveyor and cutter assembly may be removed easily, if required, to provide a larger cargo area; and e) the apparatus may be of minimal draft thus to operate in shallow water and discharge its contents directly onto land.

According to the present invention there is provided apparatus for collecting aquatic vegetation comprising a boat; a collecting conveyor mounted on the boat and movable between a first position in which a remote end of its conveying surface extends externally of and downwardly from the boat, to be submerged, and a second position in which it extends upwardly from the boat; and a storage conveyor within the boat having a conveying surface movable longitudinally within the latter; the conveyors being mutually disposed so as to be capable of transferring vegetation from one to the other; each said conveyor being reversible in direction, whereby vegetation harvested by the collecting conveyor may be accumulated on the storage conveyor and subsequently discharged therefrom in the reverse direction via the collecting conveyor when placed in said second position for offloading.

Preferably the apparatus also includes a cutting device mounted at or close to the input end of the collecting conveyor so that cut vegetation is collected by the latter. The height of the outboard end of the collecting conveyor and thus the cutting device, is adustable as required to a depth in excess of 1.5 metres and preferably almost 2 metres. The cutting device itself may be mounted in such a way as to be pivotable downwardly relative to one side of the free end of the collecting conveyor thus allowing vegetation to be cut from either a sloping or a level surface.

The storage conveyor mounted inboard is positioned to collect vegetation discharged from the collecting conveyor when the collecting conveyor is in the first position. The storage conveyor is moved incrementally in one direction as vegetation is accumulated upon it to distribute the collected vegetation along the boat. The storage conveyor is later moved incrementally in the reverse direction to return the vegetation onto the collecting conveyor when the latter is in its second position for offloading the stored vegetation.

Preferably the conveying surface of the collecting conveyor comprises a mesh material which runs around a pair of transport rollers, and the mesh size is in the range 1 to 10cm.

Preferably also a second layer of mesh with mesh size between 0.5 and 1.0cm is superimposed over the first layer when collecting small aquatic weeds.

The storage conveyor is slatted to permit drainage from the vegetation, and a bilge pump is used to remove water from the boat.

Conveniently a hydraulic ram or similar device is used to move the collecting conveyor between its first and second positions.

Additional side cutters may be fitted to the collecting conveyor when it is to be used for clearing very dense vegetation.

The slats of the storage conveyor are arranged to be clear of the collecting conveyor when the latter moves between its two positions.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is schematic isometric view of apparatus for collecting aquatic vegetation made in accordance with the invention; Fig. 2 is a partial side view of the apparatus in a first operative mode; Figs. 3 to 5 are similar side views showing the apparatus in progressively advanced modes of operation; and Fig. 6 is an hydraulic circuit diagram.

Referring to the drawings, the apparatus for cutting and collecting aquatic vegetation comprises a boat hull 10 having a flat bottom and shallow draft. Brackets 11 extend upwardly from its bow to support pivotally a collecting conveyor 15 comprising a rectangular framework 12 with a pair of guide rollers 13 connected by drive chains 14 mounted at either end of the framework 12 and serving to support the conveying surface in the form of a wire mesh 16.

A reciprocating cutter 17 is mounted at one end of the framework 12. Hydraulic motors 18 and 19 are provided to drive the conveyor 15 and the cutter 17. The framework 12 is connected at its inboard end to the hull 10 also by a hydraulic ram 20.

Sprockets 21 within the hull 10 support a pair of drive chains 22 which mount a series of conveyor slats 23 forming a storage conveyor. The chains 22 are driven by a hydraulic motor 24.

A power unit 25 drives a propeller beneath the hull 10, and steering means for the boat are provided at 26.

Controls 27 for the various hydraulic motors and the hydraulic ram 20 are sited in the boat so that the operator can operate the machine safely and efficiently.

Water which drains from the collected weed and passes through the slats 23 is removed by means of a bilge pump 28, the suction side of which is fitted with a filter to prevent clogging with weed.

In use, the apparatus is easily launched from a trailer onto a body of water from which weeds are to be cleared. The angle and depth of the framework 12 and cutter 17 are adjusted by the hydraulic ram 20 actuated by a control valve C2. At the maximum depth of cutting, the framework 12 should form an angle of not more than 600 to the horizontal.

The hydraulic drive system is actuated to drive the collecting conveyor 15 and the cutter 17, by means of control valve C1.

The drive system is energised also to move the slatted part of the storage conveyor 23 to a position indicated in Figs. 1 and 2, by control valve C3, and the bilge pump 28 is actuated by means of control valve C4.

The boat may be propelled through the water at a slow speed, typically between 1 and 3 miles per hour. The cutter 17 is driven at a rate consistent with efficient cutting at the selected forward speed and the speed of the collecting conveyor 15. The operational speeds are selected depending upon the type and density of the weed being harvested.

As the boat moves across the water the cutter 17 cuts the weed at the set depth, and the cut weeds then pass onto the mesh 16 and are carried upwards to be deposited onto the storage conveyor 23 as illustrated in Fig. 2. For most types of weed the mesh may be relatively course, say between 1 and 10cm.

As the collected weed accumulates in the boat the slatted part of the storage conveyor 23 is moved progressively by means of control valve C3 to provide additional storage space until a full payload has been collected as illustrated in Fig. 3. Cutting and collecting of the weed is then discontinued and the collecting conveyor 15 is then moved by hydraulic ram 20 to the position illustrated in Fig. 3.

The operation of the apparatus is then changed so that the cut weed may be offloaded onto the bank for disposal using land-based vehicles, for example. The apparatus is moved to a suitable position to allow the collected vegetation to be discharged onto the land, and the collecting conveyor 15 and the storage conveyor 23 are actuated in the discharge mode by operation of control valves Cl and C3. This causes the conveyors to run in the opposite direction as indicated by arrows S, vegetation stored on the slatted conveyor 23 being fed onto the conveyor 15 incrementally by operation of control valve C3.

Conveyor 15 is run continuously at this stage so that the vegetation is discharged onto the land.

When all of the collected vegetation has been discharged, the slatted conveyor 23 is moved back to the position indicated in Fig. 5 by means of control valve C3.

The apparatus may then return to the harvesting site whereupon the conveyor 15 is placed in its collecting position by means of control valve C2 extending ram 20, and the cycle may begin once again.

For safety reasons it is highly desirable that means be provided to disengage the drive to the cutter 17 when the collecting conveyor 15 is in the offloading position, to avoid the possibility of accidental injury when the cutter is exposed above water. When the control valve Cl is operated so that the motor 16 turns the conveyor 15 in the offloading direction, the hydraulic circuit is so designed that non-return valves 29 render the cutter 17 inoperative. In addition, an overload device is provided in the hydraulic drive system so that the cutter stalls if it encounters a hard object. Also, the physical disposition of the brackets 11 and ram 20 will tend to permit the free end of collecting conveyor 15 to ride over such an object.

By arranging cutter 17 to be pivotally connected at one end to the framework 12 the cutter may be operated at an angle inclined with respect to the plane of the collecting conveyor surface thus to cut the lower regions of weed growing from a sloping bed. In this way, the harvesting of weeds may be carried out right up to the bank where reeds and other similar weeds may grow.

Although the steering mechanism is shown near the stern of the boat, it may instead be located at an elevated and more forward position thus affording better visibility and creating increased storage space for collected weed.

In addition to a front cutter on the collecting conveyor, side cutters may be provided and engageable when harvesting very dense weed beds.

Whilst the storage conveyor has an upwardly inclined part near the discharge end unoccupied by the slats when in a rearward position, the inclined part may, instead, be pivotable rearwardly to permit associated pivotal movement of the rear end of the collecting conveyor.

Claims (17)

1. Apparatus for collecting aquatic vegetation comprising a boat; a collecting conveyor mounted on the boat and movable between a first position in which a remote end of its conveying surface extends externally of and downwardly from the boat, to be submerged, and a second position in which it extends upwardly from the boat; and a storage conveyor within the boat having a conveying surface movable longitudinally within the latter; the conveyors being mutually disposed so as to be capable of transferring vegetation from one to the other; each said conveyor being reversible in direction, whereby vegetation harvested by the collecting conveyor may be accumulated on the storage conveyor and subsequently discharged therefrom in the reverse direction via the collecting conveyor when plced in said second position for offloading.

2. Apparatus according to Claim 1, including a cutting device mounted at or close to the remote end of the collecting conveyor so that cut vegetation may be collected by the latter.

3. Apparatus according to Claim 2, wherein the height of the remote end of the collecting conveyor and thus of the cutting device is adjustable and may extend to a depth in excess of 1.5 metres.

4. Apparatus according to Claim 2, wherein the cutting device is mounted in such a way as to be pivotable downwardly relative to one side of the remote end of the collecting conveyor thus allowing vegetation to be cut from either a sloping or a level surface.

5. Apparatus according to any preceding claim, wherein the conveying surface of the collecting conveyor comprises a continuous mesh band extending between a pair of transport rollers, the mesh size being in the region of 1cm to 10 cm.

6. Apparatus according to Claim 5, including a second layer of mesh having a mesh size of between 0.5cm and 1cm, superimposed over the first layer.

7. Apparatus according to any preceding claim, wherein the storage conveyor may be driven incrementally in a direction away from the collecting conveyor as vegetation is accumulated, thus to distribute the collected vegetation along the boat.

8. Apparatus according to any preceding claim, wherein said storage conveyor is of slatted form to permit drainage from the vegetation, a bilge pump being provided to remove water from the boat.

9. Apparatus according to Claim 8, wherein the slats ofthe storage conveyor are adapted to move clear of the collecting conveyor when the latter moves between its first and second positions.

10. Apparatus according to any preceding claim, including a hydraulic ram adapted to move the collecting conveyor between its first and second positions.

11. Apparatus according to any preceding claim, including cutting devices fitted to at least one side of the collecting conveyor.

12. Apparatus according to Claim 2, including means to prevent operation of the cutting device when the collecting conveyor is in its second position.

13. Apparatus according to any preceding claim, wherein said collecting and storage conveyors are driven by hydraulic motors.

14. Apparatus according to any preceding claim, including steering means mounted at an elevated position within the boat permitting storage of vegetation beneath the steering means.

15. Apparatus according to any preceding claim, wherein said collecting conveyor is mounted at one end of the boat whereby the vegetation is collected at and discharged from the same end of the boat, the boat being of shallow draft whereby the remote end of the collecting conveyor may be positioned over the land for discharging vegetation directly on to dry land.

16. Apparatus according to any preceding claim, wherein the collecting conveyor is mounted on the boat in such a manner that it may easily pivot upwardly if its remote end strikes a submerged object.

17. Apparatus for collecting aquatic vegetation, substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.