AU2005222550B2 - Device for removing debris from a water course - Google Patents

Abstract

A device for removing debris from a watercourse, the device including a cage rotatably mounted to a support frame and an extracting means mounted to the cage. The 5 extracting means is movable between an extended position, wherein it extends from the cage to collect the debris and a retracted position, wherein debris is deposited on the cage for subsequent removal. _711

Description

- 1 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant/s: Murray James Anderson Actual Inventor/s: Murray James Anderson Address for Service is: SHELSTON IP 60 Margaret Street Telephone No: (02) 9777 1111 SYDNEY NSW 2000 Facsimile No. (02) 9241 4666 CCN: 3710000352 Attorney Code: SW Invention Title: DEVICE FOR REMOVING DEBRIS FROM A WATER COURSE Details of Associated Provisional Application No. 2004905967 dated 14 Oct 2004 The following statement is a full description of this invention, including the best method of performing it known to me/us: File: 43697AUP00 -2 FIELD OF THE INVENTION This invention relates to a device for removing debris from a watercourse such as an irrigation channel. The device has particular application in agricultural regions, which rely upon 5 irrigation, such as cotton growing areas. However, it will be appreciated that the invention is not limited to this field of use. BACKGROUND TO THE INVENTION Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common 10 general knowledge in the field. In farming areas, water for crops is often circulated in irrigation channels. Typically, it is necessary to remove debris from the irrigation channels on a regular basis and it is preferable that the removal of debris has minimal interference on the flow of water passing through the channel. 15 One known device for cleaning irrigation channels relies on a series of chain driven scrapers. This device uses one or more chain and sprocket drives to drive a series of scrapers over fixed slats. When the scrapers reach the top of the fixed slats they are drawn around the drive sprocket, which results in the debris falling onto a conveyor. However, a disadvantage with this device is that the chains, sprockets and scrapers must 20 operate under water, thereby resulting in excessive wear and tear and susceptibility to corrosion. It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to at least provide a useful alternative. SUMMARY OF THE INVENTION 25 To this end, the present invention provides a device for removing debris from a watercourse, the device including: a cage rotatably mounted to a support frame; extracting means mounted to the cage and movable between an extended position wherein the extracting means extends from the cage to collect the debris and a retracted 30 position wherein debris is deposited on said cage for subsequent removal; and -3 a cam surface fixedly connected to said frame, said extraction means having a cam follower for engagement with said cam surface thereby extending and retracting said extracting means. Preferably, the extracting means is withdrawn into the cage in the retracted 5 position. Preferably, the extracting means includes one or more radially extending fingers. More preferably, each finger includes a curved formation at its distal end for capturing debris. Preferably, the fingers define an axially extending rake. The debris removal 10 device preferably includes a pair of the rakes fixedly connected and radially outwardly directed. Preferably, the cam surface is defined by a cam wheel eccentrically mounted with respect to the axis of rotation of the cage. More preferably, the device includes a pair of the cam wheels. 15 Preferably, the device includes one or more tie-rods for connecting the pair of rakes. Preferably, the cage includes a cylindrical drum of wire mesh such that the debris is deposited on the outer surface of the mesh. BRIEF DESCRIPTION OF THE DRAWINGS 20 A preferred form of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side elevation of a preferred embodiment of a debris removal device, shown in use in a watercourse, according to the present invention; Figure 2 is a perspective view of the debris removal device of Figure 1; and 25 Figure 3 is a sectional front elevation, taken along line 3-3 of Figure 1. DESCRIPTION OF PREFERRED EMBODIMENT Referring to the accompanying drawings, a preferred embodiment of the debris removal device 10 according to the present invention is illustrated. When in use the device is located within a water channel 12 to be cleaned and extends across the width of 30 the channel. With reference to Fig. 1, arrow I generally indicates the direction of the water flow.

- 3a The device includes a base 14, which supports a frame 16. A cylindrical cage 18 is rotatably mounted to the support frame. As best shown in Figure 2, the cage further includes a cylindrical frame 20, the circumferential surface of which is covered with a -4 mesh 22. In a practical embodiment of the present invention, the mesh is generally formed from galvanised steel, which is welded to the cylindrical frame 20. However, in future embodiments, it is proposed that the major components of the device are produced from a suitable UV-resistant hardened plastic, thereby eliminating the problem of 5 corrosion even in salt-water applications. It should be appreciated that the cage 18 may take many forms, although it is preferable that it is designed so as to permit water to pass through it without substantial impedance to the water flow. By way of example, in one practical embodiment the cage has a diameter of approximately 3 metres and a width of approximately 2.4 metres. 10 The cage is mounted on the frame 16 so as to rotate about its longitudinal axis 24. Driving the cage is a motor (not shown) with the drive being transmitted by means of a drive wheel 26, which contacts and drives against the outer circumference of the cage. It should be noted that alternative drive mechanisms, such as for example, a chain and sprocket, belt drive or direct drive may be employed. 15 An extracting means in the form of one or more axially extending rakes 28 is moveably mounted to the cage. In this respect, each rake is movable between an extended position, wherein it extends outwardly from the cage to collect debris from the watercourse, and a retracted position wherein debris is deposited on the cage for subsequent removal. 20 The rakes are generally defined by a plurality of radially extending fingers 30, the purpose of which is to capture and remove debris from the water flow. The outermost end of each finger includes a curved formation 32 designed to assist in capturing debris from the channel. Each rake is mounted within a guide track 34 for guiding its extension and retraction. 25 In the illustrated embodiment, the cage has two opposing rakes 28 offset by 180 degrees. The rakes are preferably connected together by one or more tie rods 36 such that as one rake moves to an extended position, the corresponding opposing rake moves towards a retracted position. A cam surface 42 is provided for controlling the extension and retraction of the 30 rakes 28. In the illustrated embodiment, the cam surface takes the form of a two fixed circular discs 38, which are mounted such that the axis of each disc is parallel to, but offset from, the axis of rotation of the cage. It should be appreciated that the cam surface may take alternative forms such as a single axially extending drum.

-5 One or more rollers 40 are provided at the inner end of the rakes 28 and act as cam followers. The rollers pass over the outer surface 42 of the circular discs 38 as the cage revolves thereby extending or retracting the opposed rakes 28. A scraper 44 is provided for transferring debris from the outer surface of the 5 revolving cage and directing the debris onto a conveyor 46 for transportation away from the site of the channel. In another embodiment (not shown), each rake may be biased by a biasing means, such as one or more springs, so as to maintain contact between the rollers and the discs 38. In yet another embodiment (not shown), the device 10 may include one or more 10 floats for flotation on the surface of the watercourse. In this application, the device 10 advantageously and automatically accommodates a rising or falling water depth. Referring to Figure 1, in operation, the cage 18 is driven by the drive wheel 26 so as to rotate in an anti-clockwise direction as indicated by arrow 2. As the cage rotates, the rakes move between extended and retracted positions under the action of the cam 15 surface provided by each offset circular disc 38. In this regard, phantom line 4 generally indicates the path of each rake as the cage rotates. In other words, as one rake moves into the watercourse, it moves radially outwardly to an extended position, as illustrated by arrow 3. At the same time, the opposing rake progressively moves radially inwardly to a fully retracted position to 20 allow any collected debris to be deposited on the outer surface of the cage 18. The debris is then subsequently removed by the scraper 44 and guided into the conveyor 46 to be removed from the site. Advantageously, this device may be used to remove debris from moving watercourses in almost any situation. The device is relatively lightweight and requires 25 little power. As the only parts that move under water are the rakes, wear and tear is generally minimised. Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention can be embodied in many other forms. 30

Claims (11)

1. A device for removing debris from a watercourse, said device including: a cage rotatably mounted to a support frame; 5 extracting means mounted to said cage and movable between an extended position wherein said extracting means extends from said cage to collect said debris and a retracted position wherein debris is deposited on said cage for subsequent removal; and a cam surface fixedly connected to said frame, said extraction means having a cam follower for engagement with said cam surface thereby extending and retracting said 10 extracting means.

2. A debris removal device according to claim 1, wherein said extracting means is withdrawn into said cage in said retracted position. 15

3. A debris removal device according to claim I or claim 2, wherein said extracting means includes one or more radially extending fingers.

4. A debris removal device according to claim 3, wherein each finger includes a curved formation at its distal end for capturing debris. 20

5. A debris removal device according to claim 3 or claim 4, wherein said fingers define an axially extending rake.

6. A debris removal device according to claim 5 including a pair of said rakes fixedly 25 connected and radially outwardly directed.

7. A debris removal device according to any one of the preceding claims , wherein said cam surface is defined by a cam wheel eccentrically mounted with respect to the axis of rotation of said cage. 30

8. A debris removal device according to claim 7 including a pair of said cam wheels. -7

9. A debris removal device according to any one of claims 6 to 8 including one or more tie-rods for connecting said pair of rakes.

10. A debris removal device according to any one of the preceding claims, wherein 5 said cage includes a cylindrical drum of wire mesh such that said debris is deposited on the outer surface of said mesh.

11. A debris removal device for removing debris from a watercourse substantially as herein described with reference to any one of the embodiments of the invention 10 illustrated in the accompanying drawings and/or examples.