This application claims priority from EP 20215738.4 filed on 18 December 2020, the contents of which are taken to as incorporated herein by this reference.

Technical field

The present invention relates to improvements to wear parts for a bucket for earthmoving equipment.

Background

The present invention has been created in relation to buckets used by earthmoving equipment and to wear parts/ground engaging tools connected to such buckets.

Ground engaging tools (GET) for earth-moving equipment, such as those used in mining operations, operate in a highly abrasive environment, are subjected to high impact forces and therefore wear out or become damaged through use. GET, such as teeth used on the front lip or edges of a bucket of the earth moving equipment, therefore require regular replacement.

Traditionally, GETs are welded onto the lips of buckets. When the GET come to the end of their useful life, they can be cut from the bucket, and new GET welded in their place.

Sometimes, the corners or other parts or portions of a bucket are precast in steel, and then the floor, any side structures and cast corners are welded together. Such welding is a time consuming and costly process that must usually be done in a workshop to ensure accuracy and quality of reconstruction. Downtime of equipment adds to loss of productivity and increased operating costs to a business. Structural failure of buckets is therefore to be avoided. The present invention has been realized with these problems in mind.

A specific problem relates to a bucket comprising a lip plate protected by half arrows attached to the leading edge of the lip plate of the bucket for protection of the lip plate. The two opposite corners of the lip plate are provided with GETs in the form of corner half arrows and a plurality of intermediate half arrows are attached to the leading edge of the lip plate, between the two corner half arrows. The specific problem related to this bucket is structural failure to corner portions of the lip plate of the bucket due to continued use of the bucket after the lifetime of the corner half arrow(s) is passed.

A known bucket and associated ground engaging tool are disclosed in AU2013311372B. Another known ground engaging tool of bolt-on type is disclosed in US3029534A. DE1952397U and U4044481A both relate to technology for a ground engaging tool for bucket corners.

Accordingly, an object of this disclosure is to mitigate structural failure to the lip plate of a bucket whilst reducing downtime for service and repair of the bucket including any half arrows. Summary

According to a first aspect of the present disclosure, the above-mentioned object is enabled by a corner half arrow as defined in the appended claim 1 with embodiments defined in the dependent claims. The corner half arrow is configured to be attached to a leading edge of a lip plate of a bucket, wherein the leading edge comprises a central portion and a corner portion. The central portion extends along, and coincides with, a central axis (also referred to as a third longitudinal axis), whereas the corner portion may be retracted from the central axis to define a spacing between the corner portion and the central axis. The corner half arrow comprises a back portion configured to be attached to the corner portion of the leading edge, and an inner side portion configured to be attached, directly or indirectly, to a corresponding side portion of an adjacent intermediate half arrow attached to the central portion of the leading edge. The back portion of the corner half arrow is configured such that, when the corner half arrow is attached to the intermediate half arrow, the corner half arrow fills the spacing between the corner portion of the leading edge and the central axis. The corner half arrow may further comprise a front wear portion and a side wear portion. The inner side portion may be considered to extend along an inner side portion axis, also referred to as a first longitudinal axis, whereas the back portion may be considered to extend along a first back portion axis, also referred to as a second longitudinal axis. The second longitudinal axis may in some examples form a first angle of more than 90 degrees to the first longitudinal axis.

The corner half arrow, which also may be referred to as a wear element, is configured to be attached to the leading edge of a lip plate of a bucket to provide protection against wear to the bucket when attached. Once the corner half arrow has worn out, it can be replaced with a new corner half arrow. It will be appreciated that the inventive concept relates to corner half arrows for more than one corner portion of the leading edge, such as both the right-side and left-side corner portion, and any intermediate corner portions (should the lip plate for instance be divided into two or more parts or segments). Further, it will be appreciated that the lip plate may form an integral portion of the bucket or a separate part that is attached to the bucket. The claimed configuration of the corner half arrow provides additional material at the side wear portion adjacent the back portion by making the back portion extend obliquely rearwards. Such a configuration allows the claimed corner half arrow to replace prior art corner half arrows by removing the prior art corner half arrow to free the corner portion, or corner lip portion, of the lip plate of the bucket and subsequently remove material from the lip plate of the bucket, such as by grinding or cutting, to define the spacing between the corner portion of the leading edge of the lip plate and (the extension of) the central axis to make room for the extended back portion and side wear portion of the corner half arrow. The new corner half arrow may subsequently be attached to the lip plate by welding or by a connection system (not shown in the illustrated embodiments). The increased rearward extent of the corner half arrow enables prolonged use without availing the corner portion of the leading edge for destructive wear of the lip plate of the bucket. This is turn enables the corner half arrow to reach its end-of-life at the same time as the intermediate half arrows reach their end-of-life. In prior art solutions the corner half arrows often wear out before the intermediate half arrows wear out.

Accordingly, the claimed corner half arrow is advantageous in that it mitigates damages to the corner portions of the lip plate of the bucket caused by operators continuing use of the bucket despite the corner half arrows being worn out. Also, the claimed design of the corner half arrow provides this whilst allowing for unchanged front geometry of the front wear portion of the corner half arrow, such that the bucket can handle and function as normal with no difference to the operator of the bucket as compared to when using prior art corner half arrows. The corner half arrow also works as an upgrade for existing buckets with straight left and right leading edges of the lip plates by removal of material as described above, which can be done by field workers with basic tools. Since the intermediate half arrows wear out about the same time as the new design corner half arrow, fewer production stops need be made for maintenance of individual intermediate half arrows or corner half arrows, effectively increasing availability of the bucket over time.

The back-side portion, which may extend from the inner side portion at least initially along the first back portion axis, may form a corner half arrow interior angle with the first inner side portion axis. Similarly to the corner half arrow, the intermediate half arrow may comprise a back portion configured to be attached to the central portion of the leading edge of the lip plate, wherein the back portion of the intermediate half arrow may extend along a second back portion axis. The side portion of the intermediate half arrow may extend along a second side portion axis, such that the second back portion axis and the second side portion axis of the intermediate half arrow form an intermediate half arrow interior angle. The sum of the corner half arrow interior angle and the intermediate half arrow interior angle may preferably be larger than 180 degrees.

An edge of the back portion, which may be configured to face the corner portion of the leading edge, may be curved. Hence, the edge of the back portion may be describing a convex or a concave shaped, as viewed from the lip plate of the bucket. Further, the corner half arrow may comprise an enclosing portion configured to at least partly enclose and protect the corner of the lip plate.

The first angle between the first longitudinal axis and the second longitudinal axis may in some examples be within the range of 95-120 degrees, such as within 100-105 degrees, or such as 100 degrees. The corner half arrow portion may according to some embodiments further comprise a bottom support portion extending from a bottom of the corner half arrow and rearwards of the back portion, thereby forming a shelf for receiving the leading edge of the lip plate of the bucket.

The side wear portion may extend from the front wear portion and rearwards of the back portion.

The side wear portion may be connected to the bottom support portion.

A central portion of the shelf may comprise a central recess for facing a bottom of the lip plate.

According to a second aspect of the present disclosure, the above-mentioned object is enabled by a half arrow kit comprising the above-described corner half arrow and the intermediate half arrow. Thus, the corner half arrow comprises a back portion configured to be attached to a corner portion of the leading edge of the lip plate, and an inner side portion configured to be attached, directly or indirectly, to a corresponding side portion of the intermediate half arrow. Further, the intermediate half arrow comprises a back portion configured to be attached to a central portion of the leading edge of the lip plate, adjacent to the corner half arrow. As discussed above in connection with the first aspect, the central portion extends along, and coincides with, a central axis (in the present application also referred to as a third longitudinal axis), thereby defining a spacing between the corner portion and the central axis. The back portion of the corner half arrow is configured such that it, when attached to the intermediate half arrow, fills the spacing between the corner portion of the leading edge and the (extension of the) central axis. The intermediate half arrow may further comprise a front wear portion, a first side portion for facing the corner half arrow, and a second side portion facing away from the corner half arrow. The side portion and the back portion may extend perpendicular to each other, such that the side portion of the intermediate half arrow extends perpendicular to the leading edge of the lip plate of the bucket when attached to the lip plate. Thus, when positioning the corner half arrow adjacent the intermediate half arrow with the inner side portion of the corner half arrow extending along the first side portion of the intermediate half arrow, the back portion of the corner half arrow may extend obliquely rearward from the intermediate half arrow, along the first back portion axis.

Differently worded, the above-mentioned object is enabled by a half arrow kit comprising a corner half arrow for a lip plate of a bucket, and comprising an intermediate half arrow for attachment to a leading edge of said lip plate adjacent the corner half arrow. The corner half arrow may comprise a front wear portion, a side wear portion, a back portion for attachment to the leading edge of the lip plate of the bucket and an inner side portion for facing the intermediate half arrow. Further, the intermediate half arrow may comprise a front wear portion, a first side portion for facing the corner half arrow, and a back portion for attachment to the lip plate. The back portion of the intermediate half arrow may be considered to extend along a second back portion axis, also referred to as a fifth longitudinal axis, and the back portion of the corner half arrow may be configured to extend from the inner side portion obliquely rearwards away from the fifth longitudinal axis when the corner half arrow and the intermediate half arrow are installed adjacent each other.

The technical effect is the same as for corner half arrow discussed above however with the additional advantage that the kit may form a set of perfectly matching intermediate half arrow and corner half arrow. Specifically, the increased rearward extent of the corner half arrow enables prolonged use without availing the corner portion of the lip plate for destructive wear. This enables the corner half arrow to reach its end-of-life at the same time as the intermediate half arrows reach their end-of-life. In prior art solutions the corner half arrows often wear out before the intermediate half arrows wear out. Accordingly, the claimed corner half arrow is advantageous in that it mitigates damages to the corner portions of the lip plate of the bucket caused by operators continuing use of the bucket despite the corner half arrows being worn out. Also, the claimed design of the corner half arrow provides this whilst allowing for unchanged front geometry of the front wear portion of the corner half arrow, such that the bucket can handle and function as normal with no difference to the operator of the bucket as compared to when using prior art corner half arrows. The corner half arrow also works as an upgrade for existing buckets with straight left and right leading edges of the lip plates by removal of material as described above, which can be done by field workers with basic tools. Since the intermediate half arrows wear out about the same time as the new design corner half arrow, fewer production stops need be made for maintenance of individual intermediate half arrows or corner half arrows, effectively increasing availability of the bucket over time.

The front wear portion of the intermediate half arrow of the second kit may extend parallel to the back portion of the intermediate half arrow.

According to a third aspect of the present disclosure, the above-mentioned object is enabled by a system comprising a bucket and either a corner half arrow according to the first aspect or a half arrow kit according to the second aspect. A lip plate of the bucket comprises a leading edge having a central lip portion extending along a central axis (also referred to as a third longitudinal axis) and a corner portion (also referred to as a corner lip portion) extending along a corner axis (also referred to as a fourth longitudinal axis), wherein the corner axis extends at a second angle offset to the central axis, wherein the corner angle (also referred to as a second angle) is configured such that the back portion of the corner half arrow aligns with the corner portion of the leading edge when the corner half arrow is attached to the lip plate of the bucket. Brief description of drawings

Fig. 1 shows a lip plate of a bucket with GETs in the form of half arrows attached along the front portion, or leading edge, of the lip plate for protection of the lip plate.

Fig. 2 shows an exploded view of the lip plate of fig 1 from above including the angled

/retracted right corner portion of the leading edge of the lip plate. The left corner portion of the leading edge has not yet had material cut off for fitting of the left corner half arrow.

Figs. 3-4 show the right-side corner half arrow also shown in figs. 1-2.

Fig. 5 shows a prior art right-side corner half arrow and an adjacent intermediate half arrow along with a portion of the lip plate of a bucket shown in dash-dotted lines.

Fig. 6 shows a second embodiment of a right-side corner half arrow according to the present disclosure, along with an adjacent intermediate half arrow and with a portion of the lip plate of a bucket shown in dash-dotted lines.

Fig. 7 shows a corner half arrow according to an embodiment, when attached to an intermediate half arrow.

Figs. 8a-c show corner half arrows according to some embodiments.

Table of reference numerals Detailed description

A corner half arrow for a lip plate of a bucket of an earth-moving machine will hereinafter be described with reference to the appended drawings.

Fig. 1 shows a lip plate 3 for a bucket, comprising GETs in the form of half arrows attached along the leading edge 2, or front portion, of the lip plate 3 for protection of the lip plate 3. The half arrows 1, 8 jointly present a front wear portion and respective left and right-side wear portions for protection of the lip plate 3. The typical shape of the leading edge 2 is either along a straight line extending all the way from left to right, or with a central portion 11, or central lip portion 11, and a retracted or cut off corner portion 13, or corner lip portion 13. The central portion 11 may be considered to extend along, and coinciding with, a central axis 12 (in the following also referred to as a third longitudinal axis 12), whereas the corner portion 13 may be considered to be retracted from the central axis 12 to define a spacing between the corner portion 13 and the central axis 12. Thus, the leading edge 2 of the lip plate 3 may be described by a straight front portion and a straight right front portion angled relatively each other as depicted in fig. 2. As also shown in fig. 2, the right front portion has been cut off at an angle to its original straight shape (compare to the left front portion in fig. 2 with its original straight shape before being cut), thereby revealing the above- mentioned spacing to the central axis 12. The spacing may be formed as a triangular space not previously available. Before attaching the left corner half arrow 1 to the lip plate, the same procedure may be performed on the straight left front portion of the leading edge shown in fig. 2 to remove material obliquely outwards-rearwards. The side portions of prior art intermediate half arrows typically extend perpendicular to the leading edge 2 to which they are attached. An intermediate half arrow with such a prior art design is shown in fig. 2.

A first embodiment of the new corner half arrow 1 is shown in figs. 1-2. The corner half arrow 1 comprises a front wear portion 4, a side wear portion 5, a back portion 6 for attachment to the lip 3 of the bucket 21 and an inner side portion 7 for facing an adjacent intermediate half arrow 8. The inner side portion 7 extends along a first longitudinal axis 9 (also referred to as a first inner side portion axis), and the back portion 6 extends along a second longitudinal axis 10 (also referred to as a first back portion axis). The second longitudinal axis 10 forms a first angle 17 of more than 90 degrees to the first longitudinal axis 9. The first angle 17 may also be referred to as a corner half arrow interior angle 17.

When such a corner half arrow 1 is attached to the leading edge 2 of the lip plate 3 of the bucket 21 with the inner side portion 7 of the corner half arrow 1 positioned adjacent the corresponding side portion of the intermediate half arrow 8, the back portion of the corner half arrow 1 extends further backwards than the prior art corner half arrows do, thus providing additional wear material on the corner half arrow 1 such that the corner half arrow 1 wears out later, preferably at about the same time as the intermediate half arrows 8 wear out. This enables an operator of the bucket 21 to keep on operating the bucket 21 until all of, or at least most of the half arrows are worn out without damaging corner portions of the leading edge 2 of the lip plate 3 of the bucket 21.

In this embodiment, the first angle 17 is 100 degrees, but could in other embodiments be chosen otherwise, such as in the range of 95-120 degrees or 100-105 degrees, as appropriate.

The corner half arrow 1 further comprises a bottom support portion 15 extending from a bottom of the corner half arrow 1 and rearwards of the back portion 6, thereby forming a shelf for receiving the lip plate 3 of the bucket 21. The bottom support portion 15 enables a greater area of engagement between the lip plate 3 and the corner half arrow 1, thus reducing stress and increasing robustness of the connection between corner half arrow 1 and bucket 21.

The side wear portion 5 extends from the front wear portion 4 and rearwards of the back portion 6 extending along the leading edge 2 of the lip plate 3. In other embodiments, the side wear portion 5 could alternatively extend only to the back portion 6. Further, the side wear portion 5 is connected to the bottom support portion 15. In this embodiment, the corner half arrow 1 is molded in one piece, including the connection between the bottom support portion 15 and side wear portion 5 but any other suitable manufacturing method may be used instead.

Also, as shown in figs. 3 and 4, a central portion of the shelf comprises a central recess for facing a bottom of the lip plate 3. The central recess is visible once the front wear portion is worn out and thus provides a visual indicator for wear. In other embodiments, the central recess may alternatively have other shapes or be omitted.

See figs. 5-6 for comparison of a prior art corner half arrow and a corner half arrow 1 according to a second embodiment of the present disclosure with the lip plate shown in dash- dotted lines. As shown, the corner half arrow is provided with a back portion configured to compensate for material that has been removed from the leading edge 2 of the lip plate 3 by wearing or cutting, thus defining an angle 18 to the central axis 12.

Fig. 7 illustrates a corner half arrow 1, which may be similarly configured as the corner half arrows discussed above in connection with for instance figs. 1-4. Thus, the inner side portion of the corner half arrow 1 may extend along a first inner side portion axis 9 and form a corner half arrow interior angle 17 to the first back portion axis 10. The corner half arrow 1 may be configured such that when attached to the corner portion of the leading edge 2 of the lip plate 3, the first inner side portion axis 9 can be aligned with a second side portion axis 20 along which the corresponding side portion of the intermediate half arrow 8 extends. The corresponding side portion of the intermediate half arrow 8 may thus be arranged adjacent to, and facing, the inner side portion of the corner half arrow 1. The intermediate half arrow 8 may have a back portion attached to the central portion of the leading edge 2 and extending along a second back portion axis 16, which may form an intermediate half arrow interior angle 19 to the second side portion axis 20.

As illustrated in fig. 7, the intermediate half arrow interior angle 19 and the corner half arrow interior angle 17 may together form a sum exceeding 180 degrees.

Figs. 8a-c illustrate different examples of the shape of the back portion 6 of the corner half arrow 1. In the present figures, the back portion 6 is attached to the corner portion of the leading edge 2 of the lip plate 3 of the bucket 21. The illustrated corner half arrows 1 may form part of a kit comprising a plurality of corner half arrows, having various shapes, from which a corner half arrow may be selected to match a corresponding shape of the corner portion of the leading edge 2. Alternatively, or additionally the corner portion may be shaped, for example by cutting, into a shape that can be fitted with the back portion 6 of the corner half arrows 1.

The back portion 6 may be shaped to at least partly enclose a corner of the corner portion to protect the corner portion from being worn. The enclosing part 22 of the back portion 6 may further be employed to improve the attachment to the lip plate 3 of the bucket 21.

Figs. 8a and 8b illustrate examples wherein the back portion 6 at least initially extends along a first back portion axis 10, as seen from the inner side portion, which intersects the central axis of the leading edge 2 of the lip plate 3. In fig. 8a the back portion 6 of the corner half arrow 1 follows two different axes - first the first back portion axis 10, and then another axis intersecting the first back portion axis 10. In fig. 8b the back portion 6 instead describes a curved line, extending into the lip.

Fig. 8c illustrates a further example, wherein the edge of the back portion 6 is curved concavely into the corner half arrow 1, following a rounded contour of the corner portion of the leading edge 2.

As mentioned above, the corner half arrow 1 may be provided as part of a kit comprising both the above-described corner half arrow 1 and the above referenced intermediate half arrow 8. The intermediate half arrow 8 may comprise a front wear portion, a first side portion for facing the corner half arrow 1, a second side portion facing away from the corner half arrow 1, and a back portion for attachment to the leading edge 2 of the lip plate 3 of the bucket 21, wherein the side portion and the back portion extend perpendicular to each other as shown in fig. 2.

In other words, the half arrow kit comprises a corner half arrow 1 for a leading edge 2 of a lip plate 3, and comprising an intermediate half arrow for attachment to said leading edge 2 adjacent the corner half arrow 1, wherein the corner half arrow 1 comprises a front wear portion 4, a side wear portion 5, a back portion 6 for attachment to the leading edge 2 of the lip plate 3 and an inner side portion 7 for facing the intermediate half arrow 8. The intermediate half arrow 8 comprises a front wear portion, a first side portion for facing the corner half arrow 1, and a back portion for attachment to the leading edge 2 of the lip plate 3. The back portion of the intermediate half arrow 8 extends along a fifth longitudinal axis 16 (also referred to as a second back portion axis), and the back portion 6 of the corner half arrow is configured to extend from the inner side portion 7 obliquely rearwards away from the fifth longitudinal axis 16 when the corner half arrow 1 and the intermediate half arrow 8 are installed adjacent each other. The front wear portion of the intermediate half arrow 8 extends parallel to the back portion of the intermediate half arrow 8 but could in other embodiments alternatively extend obliquely to the back portion of the intermediate half arrow 8.

Also, the corner half arrow or the kit could be provided together with a lip plate and/or a bucket, thereby forming a system for attachment to an earth moving machine. A lip plate 3 of the bucket comprises a leading edge 2 having a central portion 11 (shown with dash-dotted lines in fig. 2) extending along a third longitudinal axis 12 and a corner portion 13 (shown with dashed lines in fig. 2) extending along a fourth longitudinal axis 14 (also referred to as a corner axis). The fourth longitudinal axis 14 extends at a second angle 18 offset to the third longitudinal axis 12. The second angle 18 is configured such that the back portion 6 of the corner half arrow 1 aligns with the corner portion 13 when the corner half arrow 1 is attached to the leading edge 2 of the lip plate 3 of the bucket 21.

It should be understood that the various edges and portions defined as extending along respective longitudinal axes are typically straight portions/edges but that they in other embodiments alternatively could be arcuate, wave shaped or otherwise shaped as long as they still extend generally along the respective longitudinal axis referred to.

The herein described half arrows are designed to be attached to the lip 2 by welding but they could alternatively be redesigned to be attached by a mechanical connection system releasably holding the GET to the bucket (not shown).

It will further be appreciated that although the embodiments discussed above with reference to figures l-8c refer to right-side corner half arrows, the inventive concept should not be construed as limited to a particular corner of the lip plate. On the contrary, the present inventive concept may as well be applied to left-side corner half arrows.