LOW HEIGHT MATERIALS HANDLING MACHINE

Field of the Invention

This invention relates to a low height materials handling machine. In particular the invention is concerned with a low height materials handling machine which can be used on mining sites.

Background Art

The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

Mining sites generally include numerous assemblies for handling and moving bulk loose materials such as iron ore, coal and alumina. These assemblies are normally provided in the form of moving conveyors, such as belt conveyors, chain conveyors and mesh conveyors, bucket elevators, pan feeders and other machinery. At some mining sites, conveyors span several kilometres. Also, these handling assemblies are associated with other machinery such as conveyor drive assemblies, crushers, feeders, kiln drives and support bearings.

It is not uncommon during normal operation of the mentioned handling assemblies than an amount of bulk material will be spilled. Such spilled material can include crushed ore, crushed rock, or fine dust that will tend to accumulate at locations where frequent spillage occurs. If these locations are not periodically cleared and then later caused to come into contact with water, for example as a result of rain, the spilled material will undergo an amount of compaction. As skilled persons will readily attest, such accumulated and compacted spillage significantly contributes to causing damage to the handling assemblies and their associated machinery.

The difficulty with clearing spilled material is that conveyors tend to have relative low ground clearances. Manual cleaning under conveyors with the use of shovels, rakes or high pressure water hoses requires that a worker crawl underneath moving machines to clean out spillage. Such cleaning activity is both

cumbersome and extremely dangerous. Also, as conveyors cannot be stopped as this would cause an entire mining operation to be halted, only a bare minimum of cleaning operation is generally undertaken proximate mining conveyors. This factor contributes to breakdowns in associated machinery. It is accordingly an object of the invention to address the difficulty in having spillage cleared from locations proximate conveyors used at mining sites.

Disclosure of the Invention

According to the present invention there is provided a materials handling machine having a chassis, a bucket assembly at the front of the chassis for handling materials, and means for driving the machine, wherein the chassis has a maximum ground clearance of about 560mm.

The bucket assembly preferably includes a bucket which can be raised and lowered, wherein the maximum ground clearance of the bucket when raised is about 680mm. The bucket is advantageously attached to the chassis via a boom. The boom is preferably pivotally attached at one end to a top portion of the chassis and at another end to a rear portion of the bucket. The bucket preferably comprises a generally horizontal base wall, a generally vertical rear wall, an open front and side walls which extend between the rear wall and open front. The bucket preferably comprises two parts, being a bucket rear wall portion and a bucket base portion. Typically the bucket rear wall portion and the bucket base portion are pivotally connected to one another at a pivot point adjacent a top portion of the bucket rear wall portion. The bucket rear wall portion preferably forms the rear wall and part of the side walls of the bucket while the bucket base portion forms the base wall and the remainder of the side walls.

The bucket assembly preferably includes means for pivoting the bucket base portion relative to the bucket rear wall portion as required. The pivoting means preferably comprises at least one hydraulic clamp cylinder, wherein a lower barrel end of the clamp cylinder is attached to the bucket rear wall portion while the

actuating arm end of the clamp cylinder is attached to a top end of the bucket base portion.

The drive means preferably comprises two track assemblies which are respectively mounted on opposite sides of the chassis. Side portions of the chassis preferably include open cavities for housing drive components of the track assemblies.

The chassis is preferably substantially shaped as a rectangular prism and is formed generally as a closed hollow shell which defines an internal space. The internal space can preferably be accessed via removable and/or pivotable covers. The covers of the machine are preferably formed from heavy metal plates in order to protect the machine from damage while still allowing access to the internal space. The covers and walls of the chassis are preferably designed to allow the shell of the machine to withstand the effects of impacts and possible contaminants. The materials handling machine preferably includes an engine assembly and an hydraulic assembly which can be housed inside the chassis internal space, in use the engine assembly can drive a pump of the hydraulic assembly which in turn can actuate the drive means via hydraulic motors.

The materials handling machine preferably includes means for adjusting the tilt angle of the bucket relative to the boom. The tilt adjusting means preferably includes an hydraulic tilt cylinder which has its barrel end attached to the chassis and its actuating arm end attached to a lower end of the rear wall portion of the bucket.

The materials handling machine preferably includes lift adjusting means for adjusting the lift angle of the boom relative to the chassis. The lift adjusting means preferably includes an hydraulic lift cylinder which has its barrel end attached to the chassis and its actuating arm end attached to the boom.

Each track assembly preferably includes a continuous rubber track which can engage the ground. The continuous rubber track extends around a toothed drive sprocket, a front idler and at least one load roller. The load roller is typically located in position between the drive sprocket and the front idler. The drive

- A - sprocket preferably has a diameter of about 370mm, the front idler preferably has a diameter of about 200mm while the load rollers have a diameter of about 150mm. The operative lowest peripheral points of the drive sprocket, front idler and load roller are preferably substantially aligned horizontally for engaging the track towards the ground.

Typically the track assembly comprises a plurality of load rollers.

Each rubber track preferably includes an internal longitudinal channel which has a number of spaced apart cavities therein for engagement by teeth of the drive sprocket. The drive sprocket is preferably coupled to and driven by an hydraulic motor mounted on the chassis. The external surface of the tracks preferably includes spaced apart lateral splines.

The front idler and load rollers are preferably rotatably mounted about a frame which is longitudinally movable via an hydraulic track cylinder in order to adjust tension in the track when required. The hydraulic assembly preferably actuates the clamp cylinders, the tilt cylinder, the lift cylinder, the two hydraulic drive motors, and the two track cylinders.

The materials handling machine preferably includes control means allowing it to be controlled by remote control. The machine preferably also includes proximity sensors such that it can automatically shut down when it detects that is proximate a remote control device operated by a user. The materials handling machine is preferably programmable to work only within a set zone marked by perimeter markers such that it will be caused to shut down automatically if it moved outside its set zone.

Brief Description of the Drawings The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings wherein:

Figure 1 shows a materials handling machine in accordance with a preferred embodiment of the present invention, where Figure 1 (a) provides a side view, Figure 1(b) a plan view and Figure 1(c) a rear view of the machine;

Figure 2 schematically illustrate internal components of the materials handling machine where Figure 2(a) provides a side view, Figure 2(b) a plan view and Figure 2(c) a rear view of the machine;

Figure 3 is an enlarged schematic side view of a bucket and corresponding lifting and tilting assembly for use in the materials handling machine of

Figure 1 and 2;

Figure 4 schematically illustrates the bucket of Figure 3 in lifted and levelled positions; and

Figure 5(a) provides an enlarged schematic side view of one track assembly of the materials handling machine, where Figure 5(b) shows a cross-sectional view along the line A-A of Figure 5(a), Figure 5(c) shows a cross-sectional view along the line B-B of Figure 5(a), Figure 5(d) shows a cross-sectional view along the line C-C of Figure 5(a), and Figure 5(e) shows a cross-sectional view along the line D-D of Figure 5(a). Best Mode(s) for Carrying Out the Invention

Figure 1 and Figure 2 show a materials handling machine in accordance with a preferred embodiment of the present invention, generally indicated with the reference numeral 10. The materials handling machine 10 generally includes a chassis 12, a bucket assembly 14 which has a bucket 30 at the front of the chassis 12, and driving means provided in the form of two track assemblies 16 mounted respectively on opposite sides of the chassis 12. The operation of the bucket assembly 14 and the track assemblies 16 will be described below.

The chassis 12 is substantially shaped as a rectangular prism and is formed generally as a closed hollow shell defining an internal space 13 therewithin. The space 13 can be accessed via removable and/or pivotable covers 15. As shown in Figure 2(b), the materials handling machine includes an engine assembly 18 and an hydraulic assembly 20 housed within the chassis internal space 13.

The chassis 12 is produced from a material which is suitable to ensure that the engine assembly 18 and hydraulic assembly 20 as well as other components of the machine 10 are housed safely and protected against impacts resulting from

collisions and falling debris. The engine assembly 18 is used to drive a pump 17 of the hydraulic assembly 20. The hydraulic assembly 20 operates hydraulic cylinders (described below) and hydraulic drive motors 21 of the track assemblies 16. Side portions of the chassis 12 include open cavities 22 for housing the drive components of the track assembly 16 as will be described below.

The top covers 15 of the materials handling machine 10 are formed from heavy metal plates to protect the machine 10 from damage and which will, in turn, allow access to the internal space 13. The top covers 15 and the walls of the chassis 12 are designed to provide that the external shell of the machine 10 is robust and sufficiently rugged to withstand impacts from falling lumps of ore and rock as well as the effects of contaminants such as grease, water and dust. The materials handling machine 10 is accordingly able to withstand the rough treatment often inflicted on mining site machinery.

One of the unique features of the materials handling machine 10 is that its chassis 12 has a maximum ground clearance of only about 560mm. Such ground clearance is very low when compared to other known materials handling machines. Furthermore, the maximum height of a lip 57 of the bucket 30 when located in a raised and level position (see position 30b in Figure 4 in this regard) is only about 680 mm. The materials handling machine 10 has a width of only about 1050mm and a maximum length of about 2240mm. These dimensions allow the materials handling machine 10 to be driven and manoeuvred underneath low height moving conveyor assemblies and other assemblies where a worker would typically have to crouch or bend over in order to gain access.

Figure 3 shows the bucket assembly 14 of the materials handling machine 10. The bucket assembly 14 of this embodiment comprises the bucket 30 which is attached to the chassis 12 via a boom 33. The boom 33, in turn, is pivotally attached at ends 34 and 35 respectively to a top portion of the chassis 12 and to the rear of the bucket 30. The bucket 30 is shaped similar to a bucket of a conventional front end loader and includes a generally horizontal base wall 36, a generally vertical rear wall 37, side walls 38 which extends between the base wall 36 and the rear wall 37, and an open front 39.

The bucket 30 comprises two parts, namely a rear wall portion 40 and a bucket base portion 41. The rear wall portion 40 and the bucket base portion 41 are pivotally connected to each other at a pivot point 42, located adjacent a top portion of the rear wall portion 40. The rear wall portion 40 of this embodiment forms the rear wall 37 and a part 38a of the side walls 38. The bucket base portion 41 on the other hand forms the base wall 36 and the remainder 38b of the side walls 38.

Figure 3 shows the bucket with its rear wall portion 40 and bucket base portion 41 in a closed position. In order to locate the bucket 30 in its open position, the bucket base portion 41 is caused to pivot substantially away from a lower section 46 of the rear wall portion 40 about a pivot point 42. This pivotal movement is generally indicated by arrow 43. In the open position of the bucket 30, the base wall 36 is separated from the rear wall 37 and the side wall portions 38a and 38b are separated from each other along a parting line 44. Pivoting of the bucket base portion 41 relative to the rear wall portion 40 is effected by two hydraulic clamp cylinders 45 which are located on either side of the bucket 30 (see in this regard also Figure 1 and Figure 2). It is pointed out that a lower barrel end of each clamp cylinder 45 is attached to the rear wall portion 40 of the bucket 30 at pivot points 47, while the actuating arm end of each clamp cylinder 45 is attached to a top end of the bucket base portion 41 at pivot points 48. It will accordingly be appreciated that the bucket 30 is of a "clamshell" design allowing it to scrape, doze, load and carry materials of different consistencies

The tilt angle of the bucket 30 about the pivot point 35 can be adjusted as required with the use of an hydraulic tilt cylinder 49. A barrel end of the tilt cylinder 49 is attached to the chassis 12 at a pivot point 50 while the actuating arm end of the tilt cylinder 49 is attached to a lower end of the rear wall portion 40 at a pivot point 51. The tilt cylinder 49 can accordingly be used to rotate the bucket 30 to a required orientation thereby allowing scraping, dozing or the loading and carrying of material. The angle of the boom 33 relative to the chassis 12 and about the pivot point 34 can be adjusted as required with the use of an hydraulic lift cylinder 52. In this

case a barrel end of the lift cylinder 52 is attached to the chassis 12 at a pivot point 53. The actuating arm end of the lift cylinder 52 on the other hand is attached to the boom 33 at a pivot point 54. As shown, the pivot point 54 is located adjacent the boom pivot point 35. The lift cylinder 52 can accordingly be used to lift the bucket 30 to a required height from the ground.

Due to the fact that the tilt cylinder 49 can cause the angle of the bucket 30 to be adjusted relative to the boom 33, the bucket 30 can be made to be "self-levelling" at all times, thereby ensuring that materials are retained therein.

Figure 4 schematically illustrates a lifting and tilting operation of the bucket 30. In Figure 4 line 55 represents the lift cylinder 52 lifting the boom 33 while line 56 represents the tilt cylinder 49 pivoting the bucket 30 relative to the boom 33. As shown, the bucket 30 can be held level at position 30b in order to retain materials therein, or can be tipped downwardly at position 30a in order to discharge materials. Figure 5 shows one of the two track assemblies 16 of the materials handling machine 10. Each track assembly 16 includes a continuous rubber track 61 for engaging a ground surface to be traversed by the materials handling machine 10. Each continuous rubber track 16 extends about a toothed drive sprocket 60, a front idler 62 and three load rollers 63. As shown, the three load rollers are located between the drive sprocket 60 and the front idler 62.

The drive sprocket 60 has a diameter of about 370mm, the front idler 62 a diameter of about 200mm while the load rollers 63 have a diameter of about 150mm each. The lowest peripheral points of the drive sprocket 60, front idler 62 and load rollers 63 are substantially horizontally aligned in order to engage the rubber track 61 along a ground surface.

The track 61 includes an internal longitudinal channel 65 which has a number of spaced cavities 66 therein to facilitate engagement with teeth 67 of the drive sprocket 60. The drive sprocket 60 in turn is coupled to and driven by the hydraulic motor 21 mounted to the chassis 12. Rotation of the hydraulic motor 21 will thus translate into rotation of the track 61. Although not shown in the drawings, the external surface of the track 61 may include a number of laterally

spaced apart extending splines for ensuring sufficient traction while the materials handling machine 10 is caused to traverse a surface.

The front idler 62 and load rollers 63 are rotatably mounted about a frame 64. As shown in Figures 5(b) to 5(d), the front idler 62 and load rollers 63 each respectively include first and second wheels 62a/62b and 63a/63b which are located on opposite sides of the frame 64. Each pair of wheels 62a/62b and

63a/63b is rotatably mounted with the use bearings 69 which are located about respective shafts 70 that extend through the frame 64. Each of the wheels

62a/62b and 63a/63b engage internal portions 71 of the track 61 at both ends of the longitudinal channel 65.

Each frame 64 is movable in a longitudinal direction under the influence of an hydraulic track cylinder 68. The hydraulic track cylinder 68 has its cylinder end attached to the chassis 12 at pivot point 72 and its actuation arm end attached to the frame 64 at pivot point 73. In use the track cylinder 68 can cause the front idler 62 and load rollers 63 to move relative to the drive sprocket 60 in order to adjust the tension in the track 61.

In order to cause the frame 64 to move in a longitudinal direction only, the frame 64 is connected at two spaced intervals with slide blocks 74. As shown the slide blocks extend laterally towards the chassis 12. At the chassis end, the slide blocks 74 include upper and lower flanges 75 which are engaged and retained by upper and lower formations 76 having recesses 77 therein. The recesses 77 retain the flanges 75 laterally, but allow the slide blocks 74 to move in a longitudinal direction.

The materials handling machine 10 can accordingly be propelled by the rubber tracks 61 which are hydraulically driven. This arrangement provides the materials handling machine 10 with sufficient traction to enable it to traverse concrete as well as earth floors. The materials handling machine 10 is further capable of climbing over accumulated piles of dirt and spillage during both wet and dry conditions.

In use, the hydraulic assembly 20 can actuate the two clamp cylinders 45, the tilt cylinder 49, the lift cylinder 52, the two hydraulic drive motors 21 , and the two track cylinders 68.

The materials handling machine 10 includes control means, here in the form of a control unit 80, shown in broken lines in Figure 1 (a), which is controlled by radio frequency from a remote control 82. This feature ensures that the materials handling machine is highly manoeuvrable.

The materials handling machine 10 also includes safety features 84 such as proximity sensors and can also be programmable to work only within a set zone marked by perimeter markers, not shown. The control unit 80 can also be programmed to shut down automatically when it detects that the materials handling machine 10 is too close to the remote control 82 held by the operator or if it moved outside its set zone. The remote control 82 conforms with Australian Standards for electronic controls AS4240:1994. The present invention accordingly provides a machine which is low enough to crawl under the lowest conveyors so that it can remove spilled material by "dozing" or "bucket loading" the material away. By ensuring that spilled materials are removed timeously the conveyor and its associated drive machinery will be protected against damage resulting from compacted and accumulated spilled material. The fact that the materials handling machine is unmanned and remote controlled allows it to crawl under moving machinery to remove spilled material without endangering persons or other equipment.

The advantage of employing a two piece bucket, commonly known as a "clam shell bucket", is that it will allow the boom to remain at a constant level while the bucket is discharged, thereby allowing the bucket to re-engage at the same level. This permits a constantly level finished ground surface.

Use of a materials handling system in accordance with the invention will prevent that whole sections of a conveyor be shut down for cleaning activities. It will accordingly be appreciated that the above materials handling machine can contribute to mining site safety as it will replace dangerous and arduous manual cleaning by a person having to crawl under moving machinery. It is envisaged

that the materials handling machine 10 will also reduce premature breakdowns of equipment, after hour callouts, expensive and unbudgeted repairs and modifications to plants, thereby contributing to cost savings for a mining site.

Although a preferred embodiment of the invention has been described, it will be apparent to skilled persons that modifications can be made to the above embodiment or that the invention can be embodied in other forms. For example, the materials handling machine can be controlled by wire instead of remote control.

Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.