AU2022251145A1 - An excavator bucket - Google Patents

Abstract

An excavator bucket includes a material receiving volume and a mouth through which material can be transferred into and from the material receiving volume, the excavator bucket including: a frame that defines the mouth, and a replaceable shell component that defines at least part of the material-receiving volume.

Description

AN EXCAVATOR BUCKET

FIELD OF THE INVENTION

The invention relates to an excavator bucket for use in the mining and construction industries.

Specifically, although by no means exclusively, the invention relates to an excavator bucket for holding material, such as rocks from quarries, material from mines, and the like.

The invention also relates to a method of repairing an excavator bucket.

The invention also relates to an excavator for excavating and moving material, the excavator comprising an excavator bucket for holding material.

BACKGROUND ART

Buckets are commonly used in the mining and construction industries for holding material, such as rocks from quarries and material from mines.

Earthmoving equipment generally falls into one of two categories: loaders; and excavators.

Loaders have a ‘front loader’ type bucket arrangement wherein the bucket moves in the direction of travel of the loader and digs and scoops material into the bucket in a forward motion.

By contrast, excavators have a ‘backhoe’ type bucket arrangement which comprises an excavator bucket on the end of a multiple-part, typically two-part, articulated arm. In use, the excavator bucket is drawn backwards towards the excavator and digs and lifts material into the bucket in a backward motion.

Typically, excavators are used to dig up material from or on the ground in a quarry or mine and deliver the material to a tray of a haulage truck or other vehicle or an in-pit conveyor that transports the material from the quarry or mine. An excavator bucket typically comprises walls, including a floor, opposed side walls, a rear wall and a forwardly-facing lip that define a material receiving volume. The bucket has a mouth for receiving material into the ground -receiving volume.

A major consideration for excavator bucket design is that material in the mining and construction industries is often very hard and abrasive and, while in use, material flow into and out of the bucket wears the inside surfaces of walls of the bucket.

Furthermore, moving an excavator bucket against material, such as when excavators move its bucket towards the excavator to displace material into the bucket, wears outside surfaces of the floor and walls of bucket.

Buckets can be repaired to an extent by welding plates to patch-up the worn portions of walls. However, beyond a certain point the buckets will inevitably require replacement.

A common way of mitigating issues related to wear of bucket walls is to apply wear parts to the buckets. These wear parts are positioned in high wear areas of buckets. For example: wear liners can be applied to the inside surfaces of the floor of a bucket; heel shrouds can be applied to the external comers of the bucket; and ground engaging tools (GET), including teeth, lip shrouds, wing shrouds, can be applied to a leading edge of bucket.

These wear parts are sacrificial. In other words, the wear parts are intended to wear instead of the wall of the bucket and are usually replaceable when they are worn out.

However, a problem with using wear parts is that they increase the overall weight of the bucket.

Furthermore, wear liners decrease the size of the material receiving volumes of the bucket.

As can be appreciated, increasing the weight of bucket and decreasing the size of the material receiving volumes of the bucket reduces the size of the payload of the bucket. This reduces the efficiency of the bucket. In addition, the replacement of wear parts is typically performed by skilled workers on site. Often the work requires lifting and manipulating the bucket. This work is expensive and there are the health and safety risks for those involved.

The applicant is aware of proposals for buckets that comprise two shell components with one of the components being replaceable - see International publication WO2018/213883 in the name of Austin Engineering Ltd and WO2017/098542 in the name of Wear Applications & Management Services Pty Ltd. The applicant has identified a number of technical problems with these buckets.

It is desirable to provide an excavator bucket that improves at least one of the above disadvantages or at least provides a useful alternative to known excavator buckets.

The above description is not an admission of the common general knowledge in Australia or elsewhere.

STATEMENT OF THE DISCLOSURE

In broad terms, the invention provides an excavator bucket having a material-receiving volume and a mouth through which material can be transferred into and from the material-receiving volume, the excavator bucket including: a frame that defines the mouth, and a replaceable shell component that defines at least part of the material receiving volume.

With the above arrangement, it is not necessary to provide (a) wear parts, such as wear resistant liners, or (b) thicker shell sections in the area where the replaceable shell component is located. The above arrangement is an alternative to excavator bucket options that have these wear part and/or thicker shell options. With the above arrangement, the replaceable shell component can be replaced relatively easily without having an impact on other sections of the excavator bucket, for example (i) the frame that defines the mouth of the material-receiving volume and (ii) a mounting arrangement for coupling the excavator bucket to an excavator. With regard to item (i), this is an advantage because, typically the frame supports wear parts, such as ground engaging tools and shrouds, and replacement of the replaceable shell component can be done without requiring replacement of these wear parts. In addition, with the above arrangement, it is possible to optimise (including minimise) the thickness of the replaceable shell component. Minimising weight maximises payload and provides an opportunity to minimise component cost.

In broad terms, the invention also provides a replaceable shell component.

The invention provides an excavator bucket for holding material, such as rocks from quarries and material from mines, the excavator bucket comprising: a material-receiving volume and a mouth through which material can be transferred into and from the material- receiving volume; a mounting arrangement for coupling the excavator bucket to an excavator; a shell comprising a floor, opposed side walls, a rear wall depending therefrom and defining the material-receiving volume and the mouth; and the shell comprising a main shell component and a replaceable shell component, the main shell component comprising a frame that defines the mouth, an upper part of each side wall, and an upper part of the rear wall, with the frame including a lip plate, a torque beam, and opposed router plates interconnecting the lip plate and the torque beam, the replaceable shell component comprising the floor, a lower part of each side wall, and a lower part of the rear wall, wherein the replaceable shell component is separable from the main shell component such that it can be replaced with another replaceable shell component when it is necessary.

In the context of this specification, the term “part” refers to some but not all of a component. In other words, part of the floor, the side walls, and the rear wall refers to some but not all of the floor, the side walls, and the rear wall.

In the context of this specification, the term “shell” refers to a unitary piece in a manufactured form.

For example, whilst the frame, the side walls and the rear wall of the main shell component may be made as separate sections, in the manufactured form of the excavator bucket the sections are welded or otherwise connected together and form the main shell component as a unitary piece.

By way of further example, whilst the parts of the floor, the side walls, and the rear wall may be made as separate sections, in the manufactured form the sections are welded or otherwise connected together and form the replaceable shell component as a unitary piece.

By way of further example, when welded or otherwise connected together, the main shell component and the replaceable shell component form the shell as a unitary piece.

The applicant has found that, instead of replacing an entire excavator bucket due to damage or wear or adding wear parts, such as wear liners or other “patches”, to the excavator bucket to extend bucket life, as is the case with many conventional buckets, with the invention only the replaceable shell component needs to be removed and a new replaceable shell component attached to the excavator bucket when wear of a current replaceable shell component reaches a point where replacement is necessary.

There are a number of advantages that follow on from this finding:

The replaceable shell component can be designed such that it comprises high wearing areas of the excavator bucket. As a result, it is not necessary to utilise wear parts, such as liners, on the inside surfaces of the floor or other sections of the excavator bucket - in other words a “linerless” design can be adopted. The replaceable shell component also makes it possible to avoid the need to utilise heel shrouds.

The absence of wear parts, such as wear liners and heel shrouds, makes it possible to reduce the weight of the excavator bucket by between 10% and 15% and to maximise the size of the ground material receiving volume. This can increase the payload of the excavator bucket by between 5% and 9%.

The absence of wear parts, such as wear liners and heel shrouds, eliminates the cost of replacing these components. A full replacement of wear parts, such as wear liners and heel shrouds, can be in the order of $100,000 to $150,000 including parts, labour and consumables.

In contrast, replacement of the replaceable shell component can be performed for $50,000 to $60,000 including parts, labour and consumables. In other words, the cost of repairing an excavator bucket can be halved.

Finally, the absence of wear parts, such as wear liners and heel shrouds, eliminates the health and safety risk associated with replacing these components, for example on site. In some embodiments, the replaceable shell component is welded to the main shell component. However, it is also envisaged that the replaceable shell component may be secured to the main shell component by any other means known in the art, for example via bolting or riveting.

In some embodiments, the replaceable shell component weighs between 2,000kg and 15,000kg. Suitably the replaceable shell component weighs between 4,500kg and 8,000kg. More suitably, the replaceable shell component weighs between 5,000kg and 7,000kg. Even more suitably, the replaceable shell component weighs about 5,500 kg.

In some embodiments, at least high wear sections of the replaceable shell component have a greater thickness than that of the main shell component.

In some embodiments, at least one of the floor, opposed side walls and the rear wall has a greater thickness in sections that are subject to more wear than other sections. This optimises the weight and material cost of the excavator bucket which in turn increases the payload of the excavator bucket.

In some embodiments, the floor has a thickness of between 25mm and 50mm.

In some embodiments, the side wall has a thickness of between 20mm and 50mm.

In some embodiments, the side wall has a thickness of between 20mm and 50mm.

In some embodiments, the excavator bucket comprises cast comer sections that cover external joined edges of the floor and each of the opposed side walls. The cast corner sections tie the floor and the opposed side walls together while also acting as a wear component of the excavator bucket.

In some embodiments, the cast corner sections are welded to the external joined edges.

However, it is also envisaged that the cast comer sections may be secured to the excavator bucket by any other means known in the art, for example via bolting or riveting.

In some embodiments, the cast corner sections have a hardness of 430-470 HB.

The cast comer sections may be made from any wear resistant material known in the art, for example wear resistant steel, such as Hardox® wear resistant steel or other suitable material such as a tungsten carbide alloy. On suitable material is Q&T450 steel.

In some embodiments, the excavator bucket comprises a ground engaging tool and a lip shroud. Ground engaging tools may include wear teeth.

An advantage of the frame being a part of the main shell component is that the frame remains intact when the replaceable shell component is removed from the excavator bucket. This is an important advantage from a structural integrity perspective.

In some embodiments, the excavator bucket is made from a material having a Brinell hardness (HBW) between 475 and 505 with a yield strength between 1,250 MPa and 1,400 MPa. Suitably, the excavator bucket is made from Hardox ® 500TUF wear resistant steel. It is emphasised that other suitable materials may be used.

The purpose of the lip plate, the torque beam and the opposing router plates that form the frame of the main shell component generally, is to provide structural rigidity for the excavator bucket, particularly under torsional loads.

In some embodiments, the torque beam is formed from a rolled steel plate. However, in other embodiments this is not the case and other options are used to form the torque beam.

The torque beam may have any suitable transverse cross-section.

The torque beam may have a triangular transverse cross-section.

In some embodiments, at least one of the lip plate and opposing router plates has a recess extending along a length of a surface that is suitable for forming a lap joint between the lip plate and/or opposing router plate and the corresponding floor and/or lower part of each side wall of the replaceable shell component. The applicant has found that a lap joint is a stronger connection than a butt joint.

In some embodiments, the excavator bucket comprises a plurality of sub-assemblies, the sub-assemblies being connected to form the excavator bucket.

In some embodiments, the plurality of sub-assemblies comprises two side sub- assemblies, each side sub-assembly being formed by connecting one of the router plates to one of the side walls of the shell.

In some embodiments, the plurality of sub-assemblies comprises a floor sub-assembly, the floor sub-assembly being formed by connecting the lip plate to the floor of the shell.

In some embodiments, the plurality of sub-assemblies comprises a roof sub-assembly, the roof sub-assembly being formed by connecting the torque beam to the rear wall of the shell.

The main shell component and the replaceable shell component may be formed so that the material-receiving volume has a curved transverse profile extending rearwardly from the mouth of the material-receiving volume.

The rearwardly-curved transverse profile may extend downwardly and rearwardly from the torque beam at the mouth of the material-receiving volume and then downwardly and forwardly to the lip plate at the mouth of the material-receiving volume.

An advantage of the curved profile is that there are no dead zones that tend not to be filled with material in use of the excavator bucket.

As a consequence, the material-receiving volume can be optimised in terms of fill capacity. This maximises the excavator bucket’s efficiency during loading and unloading cycles by increasing the payload of the excavator bucket and overall tonnes of material processed in a unit time period.

The invention also provides, a method of repairing the above described excavator bucket, wherein the method comprises: identifying when the replaceable shell component needs replacement; separating the replaceable shell component from the main shell component; and attaching another replaceable shell component to the main shell component.

In some embodiments, the step of identifying when the replaceable shell component needs replacement involves visual inspection of a wear indicator positioned on at least one of an inside and outside surface of the replaceable shell component.

In some embodiments, the step of separating the replaceable shell component from the main shell component involves cutting, for example using an oxyfuel torch.

However, it is also envisaged that the step of separating the replaceable shell component from the main shell component may be performed by any other means known in the art, for example via mechanical cutting equipment.

In some embodiments, the step of attaching another replaceable shell component to the main shell component is via welding.

However, it is also envisaged that the step of attaching another replaceable shell component to the excavator bucket may be performed by any other means known in the art, for example via bolting or riveting.

The invention also provides an excavator bucket for holding material, such as rocks from quarries and material from mines, the excavator bucket comprising: a material receiving volume and a mouth for transferring material into and from the material-receiving volume; a mounting arrangement for coupling the bucket to a machine, such as an excavator; a shell comprising a frame that defines the mouth, a floor, opposed side walls, a rear wall depending therefrom and defining the material-receiving volume and the mouth; wherein shell is formed so that the material-receiving volume has a curved transverse profile extending rearwardly from the mouth of the material-receiving volume.

The frame may include a lip plate, a torque beam, and opposed router plates interconnecting the lip plate and the torque beam.

The rearwardly-curved transverse profile may extend downwardly and rearwardly from the torque beam at the mouth of the material-receiving volume and then downwardly and forwardly to the lip plate at the mouth of the material-receiving volume.

The invention also provides, an excavator for excavating material, comprising: a support; an articulating member extending from the support; and the above described excavator bucket. The invention also provides a replaceable shell component for an excavator bucket for holding material, such as rocks from quarries and material from mines, the excavator bucket comprising a frame that defines a mouth of the excavator bucket, the replaceable shell component configured to comprise a floor, a lower part of each side wall, and a lower part of the rear wall of the excavator bucket, wherein the replaceable shell component can be connected to and is separable from the frame of the excavator bucket such that it can be replaced with another replaceable shell component.

The replaceable shell component may include the other structural features described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described further by way of example with reference to the accompanying drawings of which:

Figure 1 is a front perspective view of an excavator bucket according to an embodiment of the present invention;

Figure 2 is a rear perspective view of the excavator bucket shown in Figure 1, with the replaceable shell component separated from the main shell component;

Figure 3 is a rear perspective view of the excavator bucket shown in Figure 1 and another replaceable shell component - as indicated - prior to being attached to the main shell component;

Figure 4 is a side view of the excavator bucket shown in Figure 1 with the other replaceable shell component attached to the main shell component;

Figure 5 is a front perspective of an excavator bucket according to another embodiment of the present invention comprising cast corner sections;

Figure 6 is a side view of the excavator bucket shown in Figure 5;

Figure 7A is a front perspective view of the excavator bucket shown in Figure 5 with the replaceable shell component separated from the main shell component; Figure 7B is a front perspective view of the replaceable shell component of the excavator bucket shown in Figure 5;

Figure 8 is a top perspective view of the replaceable shell component shown in Figure 7B;

Figure 9 is a side view of the excavator bucket shown in Figure 5;

Figure 10 is a front view of the excavator bucket shown in Figure 5;

Figure 11 is a top perspective view of the excavator bucket shown in Figure 5 in which the highlighted area indicates the material receiving volume of the bucket;

Figure 12 is a top perspective view of the excavator bucket according to another embodiment of the present invention comprising replaceable wear plates, in which the highlighted area indicates the material receiving volume of the bucket;

Figure 13 is a bottom perspective view of the excavator bucket shown in Figure 12;

Figure 14A is a perspective view of the excavator bucket shown in Figure 12, with the replaceable shell component separated from the main shell component;

Figure 14B is a perspective view of the replaceable shell component of the excavator bucket shown in Figure 12;

Figure 15 is a front view of the excavator bucket shown in Figure 12;

Figure 16A is a cross-sectional view of the excavator bucket shown in Figure 15 along the line A- A including dimensions;

Figure 16B is side view of the excavator bucket shown in Figure 12 including dimensions;

Figure 17 is a cross-sectional view of a typical excavator bucket known in the art;

Figure 18 is a cross-sectional view of an excavator bucket according to another embodiment of the present invention; and

Figure 19 is a flow chart for performing a method of repairing an excavator bucket according to another embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Figures 1 to 4 show an embodiment of an excavator bucket 10 for holding material, such as rocks from quarries and material from mines.

As shown in Figure 1, the excavator bucket 10 comprises: a material-receiving volume “V”; a mouth through which material can be transferred into and from the material receiving volume V; a mounting arrangement 20; a shell 12; and a replaceable wear package.

The excavator bucket 10 is made entirely from Hardox ® 500TUF wear resistant steel. The excavator bucket 10 may be made from any other suitable wear and abrasion resistant material.

The shell 12 comprises a floor 14, opposed side walls 16, and a rear wall 18 depending therefrom to define the material receiving volume V.

The shell 12 comprises a main shell component 12a and a replaceable shell component 12b. As shown in Figure 2, the replaceable shell component 12b is separable from the main shell component 12a.

The main shell component 12a comprises: a frame 13 that defines the mouth; an upper part of each side wall 16a; and an upper part of the rear wall 18a.

The frame 13 includes: a lip plate 15; a torque beam 17; and opposed router plates 19 interconnecting the lip plate and torque beam 15, 17.

The replaceable wear package is located on the lip plate 15 and router plates 19. The wear package comprises a plurality of teeth 23, lip shrouds 24 and wing shrouds 25, collectively also known as Ground Engaging Tools (GET).

An advantage of the embodiment of the present invention shown in Figures 1 to 4 (and the other embodiments shown in the other Figures) is that the replaceable shell component 12b can be replaced without also replacing the wear package. This provides the mine operator with more flexibility in terms of maintenance scheduling.

The replaceable shell component 12b comprises: the floor 14; a lower part of each side wall 16b; and a lower part of the rear wall 18b. Suitably, the replaceable shell component 12b may be made of thicker and higher wearing material than the main shell component 12a.

As can be seen in Figure 2, the replaceable shell component 12b is separable from the main shell component 12a such that it can be replaced with another replaceable shell component 12b when it is necessary, for example when damaged or worn out.

The mounting arrangement 20 is configured for coupling the excavator bucket 10 to an excavator.

The mounting arrangement 20 comprises a pair of spaced apart brackets 22a, 22b having holes. The holes in the brackets 22a, 22b are aligned and sized such that a pin can be inserted through the holes to span between the brackets 22a, 22b. Once installed, the pin can be secured to a hitch on an articulating member (i.e. arm) of an excavator.

As can be seen in Figures 3 and 4, another replaceable shell component 12b (as indicated) can be attached to the main shell component 12a.

As shown in Figures 2 and 3 the lip plate has a recess extending along a length of a surface that is suitable for forming a lap joint between the lip plate and the floor of the replaceable shell component. The recess forms a ledge for holding the floor of the replaceable shell component while the two components are being welded together. The applicant has found that a lap joint produces a stronger connection than a butt joint.

The replaceable shell component 12b has at least one wear indicator positioned on an inside surface. As the inside surface of the replaceable shell component 12b wears, the wear indicator visually indicating to a person how much the inside surface of the replaceable shell component 12b has worn.

The replaceable shell component 12b typically weighs about 5,500 kg. However, it can be appreciated that the replaceable shell can be designed to suit an excavator bucket of any size and as such, the above stated weight is merely a preferred embodiment.

In use, instead of replacing the entire excavator bucket due to damage or wear, the replaceable shell component 12b can be removed from the main shell component 12a and a new replaceable shell component 12b attached to the main shell component 12a.

Figures 5-11 show an excavator bucket 100 according to a further embodiment of the present invention. The excavator bucket 100 functions in essentially the same manner as excavator bucket 10.

The excavator bucket 100 comprises: a material-receiving volume “VI” and a mouth through which material can be transferred into and from the material-receiving volume VI; a mounting arrangement 120; and a shell 112.

The excavator bucket 100 is also made entirely from Hardox ® 500TUF wear resistant steel.

The shell 112 comprises: a floor 114; opposed side walls 116; and a rear wall 118 depending therefrom and defining a material-receiving volume V 1.

The shell 112 comprises: a main shell component 112a; and a replaceable shell component 112b.

The main shell component 112a comprises a frame 113 that defines the mouth, an upper part of each side wall 116a, and an upper part of the rear wall 118a, with the frame 113 including a lip plate 115, a torque beam 117, and opposed router plates 119 interconnecting the lip plate and torque beam 115, 117.

The replaceable shell component 112b comprises the floor 114, a lower part of each side wall 116b, and a lower part of the rear wall 118b. The replaceable shell component 112b is separable from the main shell component 112a such that it can be replaced with another replaceable shell component 112b when it is necessary, for example when damaged or worn out.

The thickness of the floor 114 is 40mm and the thickness of the lower part of side walls 116b and rear wall 118b is 32mm. The thickness of the floor 114, lower part of side walls 116b and rear wall 118b can be varied depending on the wear rate and site conditions, such as rock/mineral hardness.

The replaceable shell component 112b weighs approx. 5.5 tonnes. The main shell component 112a weighs approx. 13.6 tonnes. The replaceable wear package (GET) weighs approx. 10.0 tonnes. The total weight of the bucket is approx. 30.5 tonnes (including an approx.500kg weld allowance).

The mounting arrangement 120 is configured for coupling the excavator bucket 100 to an excavator. The mounting arrangement 120 comprises a pair of spaced apart brackets 122a, 122b each having holes. The holes in the brackets 122a, 122b are aligned and sized such that a pin can be inserted through the holes to span between the brackets 122a, 122b. Once installed, the pin can be secured to a hitch on an articulating member (i.e. arm) of an excavator.

The excavator bucket 100 differs from the excavator bucket 10 in that the shell 112 comprises cast comer sections 140 that cover an external joined edge of the floor 114 and each of the side walls 116. The cast corner 140 sections tie the floor 114 and side walls 116 together while acting as a wear component of the excavator bucket 100. The cast corner sections 140 are welded to the external joined edge. The cast comer sections 140 are made of Hardox® wear resistant steel or any other suitable material. One suitable material is Q&T450 steel.

Figure 9 shows a mounting arrangement 122 comprising a first hole 126 and a second hole 127. The distance between the centrelines of the first and second holes 126, 127 is 1.2m. The floor 114 is offset from a line intersecting the holes 126, 127 by an angle of 16°. The maximum distance between the tip of the teeth 23 and the centreline of the first hole 123, also known as the tip bend radius is 4.3m.

Figure 9 also shows that the rear wall curves towards the floor such that a portion of the rear wall is offset from the floor 114 by an angle of 7°.

Figure 10 shows that the width of the material receiving volume VI is 4.3m.

As shown in Figure 11, the material receiving volume VI is 35m³.

Figures 12-16 show an excavator bucket 200 according to a further embodiment of the present invention. The excavator bucket 200 functions in essentially the same manner as excavator bucket 10, 100.

The excavator bucket 200 comprises: a material-receiving volume “V2” and a mouth through which material can be transferred into and from the material-receiving volume V2; a mounting arrangement 220; and a shell 212.

The excavator bucket 200 is also made entirely from Hardox ® 500TUF wear resistant steel.

The shell 212 comprises: a floor 214; opposed side walls 216; and a rear wall 218 depending therefrom and defining a material-receiving volume V2. As shown in Figure 12, the material receiving volume V2 is 22m³.

The shell 212 comprises: a main shell component 212a; and a replaceable shell component 212b.

The main shell component 212a comprises a frame 213 that defines the mouth, an upper part of each side wall 216a, and an upper part of the rear wall 218a, with the frame 213 including a lip plate 215, a torque beam 217, and opposed router plates 219 interconnecting the lip plate and torque beam 215, 217.

The replaceable shell component 212b comprises the floor 214, a lower part of each side wall 216b, and a lower part of the rear wall 218b. The replaceable shell component 212b is separable from the main shell component 212a such that it can be replaced with another replaceable shell component 212b when it is necessary, for example when damaged or worn out.

The mounting arrangement 220 is configured for coupling the excavator bucket 200 to an excavator. The mounting arrangement 220 comprises a pair of spaced apart brackets 222a, 222b each having holes 226, 227. The holes 226, 227 in the brackets 222a, 222b are aligned and sized such that a pin can be inserted through the holes to span between the brackets 222a, 222b. Once installed, the pin can be secured to a hitch on an articulating member (i.e. arm) of an excavator.

The excavator bucket 200 differs from the excavator buckets 10, 100 in that the shell 212 comprises a plurality of replaceable wear plates 240 on the underside surface of the floor 214 adjacent to the side wall 216, as shown in Figure 13. The excavator bucket 200 also differs from the excavator buckets 10, 100 in that the replaceable wear package comprises a lip wear assembly 26, as shown in Figure 13. The wear plates 240 are used as a substitute for the cast corner sections 140 of the excavator bucket 100. As shown in Figure 13, the excavator bucket also comprises a replaceable lip reinforcement plate 241 that is positioned adjacent to the lip wear assembly 26. The wear plates 240 and lip reinforcement plate 241 are made of Hardox® wear resistant steel or any other suitable material. One suitable material is Q&T450 steel.

Figure 15A shows that the mounting arrangement 222 comprises first and second holes 226, 227. The distance between the centrelines of the first and second holes 226, 227 is 0.9m.

Figure 15A also shows that the rear wall 218 curves towards the floor 214 such that a portion of the rear wall 218 is offset from the floor 214 by an angle of 10°.

Figure 15A also shows that the distance between the tip of the teeth 23 and the centreline of the first hole 226, also known as the tip bend radius, is 3.7m.

Figure 15A also shows that the distance between the floor 214 and the first hole 226, also known as the floor radius, is 3.2m.

Figure 15B shows that the maximum height of the bucket is 3.8m and the maximum depth of the bucket is 3.9m.

Figure 16 shows that the side walls 216 are offset from each other by an angle of 3°.

The maximum external width of the bucket is 3.9m and the width of the material receiving volume V3 is 3.5m.

Figure 17 shows a cross-sectional view of an excavator bucket 300 that is known in the art. The excavator bucket 300 comprises a floor 314, opposed side walls 316, a rear wall 318 depending therefrom and defining a material-receiving volume “V” and a mouth through which material can be transferred into and from the material-receiving volume V.

As can be seen from Figure 17, the floor 314 and rear wall 318 are shaped to define a profile “A”, as indicated by the red line. The profile A defines a boundary of the cross- sectional area of the material receiving volume V.

The excavator bucket 200 further comprises a torque beam 330, having a pentagon shaped profile, that extends between opposed side walls 316.

As can be seen from Figure 17, in effect, the torque beam 330 extends downwardly into the material-receiving volume V of the excavator bucket 300.

The applicant has found that this torque beam arrangement is sub-optimal for providing maximum fill capacity. Specifically, one of the consequence of the torque beam location is to create a dead zone rearwardly of the torque beam.

Figure 18 shows an excavator bucket 400 according to a further embodiment of the present invention.

The excavator bucket 400 comprises: a floor 414; opposed side walls 416; a rear wall 418 depending therefrom and defining a material-receiving volume “V”; and a mouth through which material can be transferred into and from the material-receiving volume V.

As can be seen from Figure 18, the floor 414 and rear wall 418 are curved to define a profile “B”, as indicated by the red line. The profile B defines a perimeter of a cross- sectional area of the material-receiving volume V.

Similar to the excavator bucket 300, the excavator bucket 400 also comprises a torque beam 430, that extends between opposed side walls 416, and provides structural rigidity to the excavator bucket 400.

However, unlike the excavator bucket 300, the profile B of the excavator bucket 400 extends rearwardly and downwardly from the torque beam 430 such that the torque beam 430 does not protrude into the material-receiving volume V.

The applicant has found that this type of torque beam arrangement and profile optimises the fill capacity of the material receiving volume. This is because the torque beam 430 does not obstruct the material-receiving volume V.

Furthermore, the torque beam 430 has a smaller cross-sectional area than the torque beam 330, with a triangular- shaped profile as opposed to a pentagon- shaped profile.

The applicant has found that the triangular- shaped profile provides adequate structural rigidity for the excavator bucket 400, whilst minimising the weight of the excavator bucket 400.

Figure 19 shows a flow chart for performing a method of repairing an excavator bucket 10 according to another embodiment of the present invention.

The method involves the following steps:

Firstly, identifying when the replaceable shell component 12b needs replacement. This step is ideally achieved by visually inspecting the at least one wear indicator as the replaceable shell component 12b wears.

Secondly, separating the replaceable shell component 12b from the main shell component 12a. This step is ideally achieved by cutting the join between the main shell component 12a and the replaceable shell component 12b, for example using an oxyfuel torch.

Thirdly, attaching another replaceable shell component 12b to the main shell component 12a. This step is ideally achieved by welding the join between the main shell component 12a and the replaceable shell component 12b.

As can be appreciated, the above described method steps can similarly be applied to repair the excavator bucket 100.

It will be understood to persons skilled in the art of the invention that many modifications may be made to the embodiments described in relation to the Figures without departing from the spirit and scope of the invention.

By way of example, whilst the excavator buckets 100 shown in the Figures are made entirely from Hardox ® 500TUF wear resistant steel, the present invention is not so limited and extends to the use of any suitable high wear material.

By way of example, the cast comer sections 140 shown in the Figures may be made from any wear resistant material, for example wear resistant steel, such as Hardox® wear resistant steel and Q&T450 steel. By way of example, the invention is not confined to the particular shape of excavator buckets 100 shown in the Figures. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims (18)

1. An excavator bucket for holding material, such as rocks from quarries and material from mines, the excavator bucket comprising: a material-receiving volume and a mouth through which material can be transferred into and from the material-receiving volume; a mounting arrangement for coupling the excavator bucket to an excavator; a shell comprising a floor, opposed side walls, a rear wall depending therefrom and defining the material-receiving volume and the mouth; and the shell comprising a main shell component and a replaceable shell component, the main shell component comprising a frame that defines the mouth, an upper part of each side wall, and an upper part of the rear wall, with the frame including a lip plate, a torque beam, and opposed router plates interconnecting the lip plate and the torque beam, the replaceable shell component comprising the floor, a lower part of each side wall, and a lower part of the rear wall, wherein the replaceable shell component is separable from the main shell component such that it can be replaced with another replaceable shell component when it is necessary.

2. The excavator bucket of claim 1, wherein the replaceable shell component is welded to the main shell component.

3. The excavator bucket of claim 1 or claim 2, wherein the replaceable shell component weighs between 2,000kg and 15,000kg.

4. The excavator bucket of any one of the preceding claims, wherein at least one of the floor, opposed side walls and the rear wall has a greater thickness in sections that are subject to more wear than other sections.

5. The excavator bucket of any one of the preceding claims, comprising cast corner sections that cover an external joined edge of the floor and each of the opposed side walls.

6. The excavator bucket of claim 5, wherein the cast corner sections are welded to the external joined edge.

7. The excavator bucket of claim 5 or claim 6, wherein the cast comer sections have a hardness of 430-470 HB.

8. The excavator bucket of any one of the preceding claims, wherein the torque beam is formed from a rolled steel plate.

9. The excavator bucket of any one of the preceding claims, wherein the torque beam has a triangular transverse cross-section.

10. The excavator bucket of any one of the preceding claims, wherein the main shell component and the replaceable shell component are formed so that the material receiving volume has a curved transverse profile extending rearwardly from the mouth of the material-receiving volume.

11. The excavator bucket of claim 10, wherein the rearwardly-curved transverse profile extends downwardly and rearwardly from the torque beam at the mouth of the material-receiving volume and then downwardly and forwardly to the lip plate at the mouth of the material-receiving volume.

12. A method of repairing an excavator bucket as claimed in any one of claims 1 to 11, wherein the method comprises: identifying when the replaceable shell component needs replacement; separating the replaceable shell component from the main shell component; and attaching another replaceable shell component to the main shell component.

13. The method of claim 12, wherein the step of identifying when the replaceable shell component needs replacement involves visual inspection of a wear indicator positioned on at least one of an inside and outside surface of the replaceable shell component.

14. The method of claim 12 or claim 13, wherein the step of separating the replaceable shell component from the main shell component involves cutting, for example using an oxy fuel torch.

15. The method of any one of claims 12 to 14, wherein the step of attaching another replaceable shell component to the main shell component is via welding.

16. An excavator for excavating material, comprising: a support; an articulating member extending from the support; and an excavator bucket as claimed in any one of claims 1 to 11.

17. An excavator bucket having a material receiving volume and a mouth through which material can be transferred into and from the material receiving volume, the excavator bucket including: a frame that defines the mouth, and a replaceable shell component that defines at least part of the material-receiving volume.

18. A replaceable shell component for an excavator bucket for holding material, such as rocks from quarries and material from mines, the excavator bucket comprising a frame that defines a mouth of the excavator bucket, the replaceable shell component being configured to comprise a floor, a lower part of each side wall, and a lower part of the rear wall of the excavator bucket, wherein the replaceable shell component can be connected to and is separable from the frame of the excavator bucket such that it can be replaced with another replaceable shell component.