Patent Publication Number: US-9903092-B2

Title: Excavation bucket

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/AU2012/001158, filed Sep. 26, 2012, which claims the priority of Australian Application No. 2011903970, filed Sep. 26, 2011, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     This disclosure relates to excavation buckets for use with digging equipment. The disclosure also relates to parts assembled together to form an excavation bucket including the lip of the bucket. 
     BACKGROUND OF THE INVENTION 
     Excavation buckets have long been used in the mining industry for many different types of digging operations. Excavation buckets come in many different sizes and are designed for different purposes. Many buckets, in particular larger buckets, are constructed from separately formed pieces which are then welded together to form the bucket. This is at least partly because it is easier to manufacture the excavation buckets in this way than to create the bucket as a single casting. However, one problem for such excavation buckets is that the weld joins between the assembled pieces are areas of weakness for the bucket and are prone to cracking and failure due to fatigue stress. This is a particular problem for the ground engaging lip of the bucket. 
     SUMMARY OF THE INVENTION 
     According to one embodiment, the disclosure provides a member for assembly with other members in an assembled condition to form an excavation bucket, the member forming at least part of one of the walls of the bucket when in its assembled condition, the member comprising a body having: a forward edge; a rearward edge; opposite inner and outer surfaces that extend between the edges; a first portion of the member being thicker between its inner and outer surfaces than a second portion of the member, the first portion being disposed forward of the second portion. 
     According to another embodiment, the disclosure provides a lip for assembly in an excavation bucket in an assembled condition, the lip comprising: a base portion having a front edge that forms part of a digging edge of the bucket in use and a rear edge for joining to at least one other member of the bucket when the lip is in its assembled condition; and wing members extending from opposed sides of the base portion, each wing member having: a forward edge; a rearward edge; opposite inner and outer surfaces that extend between the edges; a first portion of the member being thicker between its inner and outer surfaces than a second portion of the member, the first portion being disposed forward of the second portion. 
     According to another embodiment, the disclosure provides an excavation bucket assembly comprising a first member and a second member, each member having a joint edge that are joined to each other when the members are brought into an assembled condition to at least partly form a wall of the excavation bucket, each of the first and second members having a first portion that is thicker between its inner and outer surfaces than a second portion of the member, the first portion being disposed forward of the second portion. 
     According to another embodiment, the disclosure provides a member of an excavation bucket for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising: a body having opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; and a recess formed in at least one of the inner and outer surfaces of the member. 
     According to another embodiment, the disclosure provides a member of an excavation bucket for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising: a body having; opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; a joint edge that in use joins to a corresponding joint edge of another bucket member to form a joint in the excavator bucket; and a weakened region that is arranged to preferentially deform under load so as to relieve loading in the excavator bucket joint. 
     According to another embodiment, the disclosure provides an excavation bucket assembly incorporating first and second members that are interconnected by a joint in an assembled condition, each member comprising: a body having a joint edge that is joined to the joint edge of the other member when the members are brought into an assembled condition to at least partly form a wall of the excavation bucket, each member&#39;s body also having opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the members are in their assembled condition; and at least one of the members also comprising: a recess formed in at least one of the inner and outer surfaces of that member. 
     According to another embodiment, the disclosure provides an excavation bucket assembly incorporating first and second members that are interconnected by a joint in an assembled condition, wherein at least one of the first and second members comprises a weakened region that is arranged to preferentially deflect under load to relieve loading in the joint. 
     According to another embodiment, the disclosure provides a wear member of a wear assembly for assembly with an excavation bucket in an assembled condition, the wear member having an inner face that engages the excavation bucket when the wear member is in its assembled condition and an opposite outer face, the wear member comprising: a wrapping portion configured to wrap around an edge of the excavation bucket when in he assembled condition; and a leg extending away from the wrapping portion; wherein the inner face of the wear member bulges along a substantial portion of the leg for receipt in a recess of the excavation bucket when the wear member is in its assembled condition. 
     According to another embodiment, the disclosure provides an excavation bucket assembly comprising: a first bucket member having a forward edge and a rear edge; a second bucket member having a forward edge and a rear edge, the first and second bucket members also each having a joint edge which join to each other when the bucket members are brought into an assembled condition; and a wear member for protecting at least part of the forward edge of at least one of the bucket members, the wear member comprising a wrapping portion configured to cover the part of the forward edge of the bucket member(s) when the wear member is brought into an assembled condition with the bucket members and a leg extending away from the wrapping portion, the leg configured to be received in a recess formed in at least one of the bucket members when the wear member is in its assembled condition with the bucket members. 
     According to another embodiment, the disclosure provides a member of an excavation bucket for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising: a body having opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; and a shear support formation integrally formed with the body for protecting a wear member that is assembled with the member of the excavation bucket against shear forces in use. 
     According to another embodiment, the disclosure provides an excavation bucket assembly comprising: a bucket member for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising a body having a forward edge and a rearward edge and opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; and a wear member for assembly with the bucket member to protect at least part of the forward edge of the bucket member; wherein the bucket member also comprising a shear support formation integrally formed with the bucket member&#39;s body for protecting the wear member in its assembled condition with the bucket member against shear forces in use. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of an excavation bucket according to an embodiment of the disclosure; 
         FIG. 2  is a perspective view of the excavation bucket of  FIG. 1  with its parts in an assembled condition; 
         FIGS. 3-6  are top, rear, front and side views of the assembled excavation bucket of  FIG. 1 ; 
         FIG. 7  is a perspective view of the lip of the excavation bucket of  FIG. 1  in isolation; 
         FIGS. 8-10  are top, side and front views of the lip of  FIG. 7 ; 
         FIG. 11  is a side view of one of the integral neck hinges and cheek members of the excavation bucket of  FIG. 1 ; 
         FIGS. 12-14  are perspective, front and below views of the integral neck hinge/cheek member of  FIG. 11 ; 
         FIG. 15  is a rear perspective view of part of the excavation bucket showing wear members assembled with side walls of the bucket to protect the edges of the side walls from wear during use; 
         FIGS. 16 and 17  are perspective views of the excavation bucket of  FIG. 1  with the wear members of  FIG. 15  assembled with the excavation bucket and with further wear members assembled with the lip of the bucket to protect the lip from wear during use; 
         FIG. 18  is a perspective view of the lower of the wear members of  FIG. 15  for protecting the side wall edges of the bucket in isolation; 
         FIGS. 19 and 20  are opposite side views of the wear member of  FIG. 18 ; 
         FIGS. 21-23  are top, front and rear views of the wear member of  FIG. 18 ; 
         FIG. 24  is a perspective view of the upper of the wear members of  FIG. 15  for protecting the side wall edges of the bucket in isolation; 
         FIGS. 25 and 26  are opposite side views of the wear member of  FIG. 24 ; and 
         FIGS. 27-29  are top, front and rear views of the wear member of  FIG. 24 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part thereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein. 
     The present disclosure is directed generally to excavation buckets including members such as lips and cheek members that are formed separately and then assembled to form the excavation buckets. The present disclosure is also directed generally to wear members or shrouds used to protect the edges of the side walls of the excavation buckets against wear. 
     In one embodiment, the present disclosure provides a member for assembly with other members in an assembled condition to form an excavation bucket, the member forming at least part of one of the walls of the bucket when in its assembled condition, the member comprising a body having: a forward edge; a rearward edge; opposite inner and outer surfaces that extend between the edges; a first portion of the member being thicker between its inner and outer surfaces than a second portion of the member, the first portion being disposed forward of the second portion. 
     The body of the member may also have an intermediate portion that tapers between the inner and outer surfaces of the body from the first portion to the second portion. 
     The second portion may extend from the intermediate portion to the rearward edge of the body and the first portion may extend from the intermediate portion to the forward edge of the body. 
     In an embodiment, the member is a cast member. 
     In an embodiment, the member&#39;s body has a joint edge for joining to at least one other member of the bucket in the member&#39;s assembled condition, the joint edge extending between the rearward and forward edges, preferably substantially linearly although may be curved or have a complex shape in extension. 
     In another embodiment, the present disclosure also provides a member of an excavation bucket for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising: a body having opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; and a recess formed in at least one of the inner and outer surfaces of the member. 
     In an embodiment, the body of the member has a joint edge for engaging and joining to the at least one other bucket member in the assembled condition to form the bucket, the joint edge extending between the inner and outer surfaces of the body. 
     In an embodiment, the recess is elongated in a direction substantially parallel to the joint edge of the member. The recess may also be spaced from the joint edge of the member. 
     In an embodiment, the recess is formed in the outer surface of the member&#39;s body, but in other embodiments may be formed in the inner surface of the member&#39;s body. 
     In an embodiment, the body of the member has a forward edge and a rearward edge, the recess extending away from the forward edge. 
     In an embodiment, the body has a first portion that is thicker between its inner and outer surfaces than a second portion and the recess is formed in the first portion. In an embodiment, the recess extends across the width of the thicker first portion. 
     In an embodiment, the member also comprises a mounting formation for a wear member that in use protects the member against wear to be mounted to, the mounting formation located in the recess. 
     In an embodiment, the mounting formation does not extend beyond the surface of the member&#39;s body in which the recess is formed. 
     In an embodiment, the mounting formation comprises a boss extending from the floor of the recess. Preferably, the boss widens as it extends from the floor of the recess. 
     In another embodiment, the present disclosure provides a member of an excavation bucket for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising: a body having; opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; a joint edge that in use joins to a corresponding joint edge of another bucket member to form a joint in the excavator bucket; and a weakened region that is arranged to preferentially deform under load so as to relieve loading in the excavator bucket joint. 
     In an embodiment, the weakened region comprises a recess formed in the inner and/or outer surface of the member&#39;s body. 
     In an embodiment, the member is a side wall portion of the excavation bucket when in its assembled condition. 
     In an embodiment, the member is a wing member of a lip for the excavation bucket, the lip comprising a base portion that forms part of the digging edge of the bucket and wherein the wing member extends from the base portion at a side of the base portion. 
     In another embodiment, the present disclosure provides excavation bucket assembly comprising a first member and a second member, each member having a joint edge that are joined to each other when the members are brought into an assembled condition to at least partly form a wall of the excavation bucket, each of the first and second members having a first portion that is thicker between its inner and outer surfaces than a second portion of the member, the first portion being disposed forward of the second portion. 
     In an embodiment, the first and second members have correspondingly shaped surfaces for engagement with each other. 
     In an embodiment, the joint edges of the first and second members have substantially identical shapes in section. 
     In an embodiment, the joint edge of one of the members has a ridge extending along the length of the edge and the other member has a corresponding groove extending along the length of its joint edge. 
     In an embodiment, each of the first and second members has a forward edge that defines an outer edge of the bucket when the members are in their assembled condition and a opposite rearward edge that joins to at least one further member of the bucket when the members are in their assembled condition. The thicker first portion of each of the first and second members extends from their respective forward edges. Further, each of the first and second members have an intermediate portion that tapers from their respective thicker first portion to their respective second portion. 
     According to another embodiment, the present disclosure provides an excavation bucket assembly incorporating first and second members that are interconnected by a joint in an assembled condition, each member comprising: a body having a joint edge that is joined to the joint edge of the other member when the members are brought into an assembled condition to at least partly form a wall of the excavation bucket, each member&#39;s body also having opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the members are in their assembled condition; and at least one of the members also comprising: a recess formed in at least one of the inner and outer surfaces of that member. 
     In an embodiment, both the first and second members comprise a recess in at least one of their inner and outer surfaces. 
     In an embodiment, the recess in the first member and the recess in the second member are elongate in a direction substantially parallel to each other when the members are in their assembled condition. 
     In an embodiment, the recess in the first member is substantially identical in shape to the recess in the second member. 
     In another embodiment, the present disclosure provides an excavation bucket assembly incorporating first and second members that are interconnected by a joint in an assembled condition, wherein at least one of the first and second members comprises a weakened region that is arranged to preferentially deflect under load to relieve loading in the joint. 
     In an embodiment, the each of the first and second members comprise said weakened region. 
     In an embodiment, the weakened regions are disposed either side of the joint. 
     In an embodiment, the weakened region comprises a recess. 
     In an embodiment, the first member is a wing member of a lip for the excavation bucket, the lip comprising a base portion that forms the digging edge of the bucket when the lip is in an assembled condition with the other members to form the bucket and wherein the wing member extends from the base portion at a side of the base portion and the second member is a side wall member that forms at least part of the side wall of the bucket when in its assembled condition. 
     In another embodiment, the present disclosure provides a wear member of a wear assembly for assembly with an excavation bucket in an assembled condition, the wear member having an inner that engages the excavation bucket when the wear member is in its assembled condition and an opposite outer face, the wear member comprising: a wrapping portion configured to wrap around an edge of the excavation bucket when in he assembled condition; and a leg extending away from the wrapping portion; wherein the inner face of the wear member bulges along a substantial portion of the leg for receipt in a recess of the excavation bucket when the wear member is in its assembled condition. 
     In an embodiment, the wrapping portion is wider than the leg. 
     In an embodiment, the wear member comprises an engaging portion for engaging a mounting formation on the excavation bucket to bring the wear member into its assembled condition with the bucket. In an embodiment, the engaging portion is formed in the leg of the wear member. 
     In an embodiment, the engaging portion comprises a slot formed in the inner face of the wear member where it bulges. 
     In an embodiment, the slot opens in a distal end of the leg from the wrapping portion. 
     In another embodiment, the present disclosure provides a wear assembly for assembly with an excavation bucket in an assembled condition, the wear member comprising: a wear member as described in any of the embodiments above; and a lock for locking the wear member in its assembled condition with the excavation bucket. 
     In another embodiment, the present disclosure provides an excavation bucket assembly comprising: a first bucket member having a forward edge and a rear edge; a second bucket member having a forward edge and a rear edge, the first and second bucket members also each having a joint edge which join to each other when the bucket members are brought into an assembled condition; and a wear member for protecting at least part of the forward edge of at least one of the bucket members, the wear member comprising a wrapping portion configured to cover the part of the forward edge of the bucket member(s) when the wear member is brought into an assembled condition with the bucket members and a leg extending away from the wrapping portion, the leg configured to be received in a recess formed in at least one of the bucket members when the wear member is in its assembled condition with the bucket members. 
     In an embodiment, the recess is formed in an outer surface of one of the bucket members. 
     In an embodiment, the wrapping portion of the wear member when the wear member is in its assembled condition covers the join between the joint edges of the bucket members at the bucket members&#39; forward edge. 
     According to another embodiment, the disclosure provides a member of an excavation bucket for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising: a body having opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; and a shear support formation integrally formed with the body for protecting a wear member that is assembled with the member of the excavation bucket against shear forces in use. 
     The shear support formation may be formed on the outer surface of the body and in one form comprises a recess in the body. 
     According to another embodiment, the disclosure provides an excavation bucket assembly comprising: a bucket member for assembly with at least one other bucket member in an assembled condition to form the bucket, the member comprising a body having a forward edge and a rearward edge and opposite inner and outer surfaces that respectively define at least portions of inner and outer surfaces of the bucket when the member is in its assembled condition; and a wear member for assembly with the bucket member to protect at least part of the forward edge of the bucket member; wherein the bucket member also comprising a shear support formation integrally formed with the bucket member&#39;s body for protecting the wear member in its assembled condition with the bucket member against shear forces in use. 
     The shear support formation may comprise a recess that is shaped to receive therein a portion of the wear member. 
     Referring to Figures, some illustrative embodiments of an excavation bucket  10  are shown. As shown in  FIGS. 1 and 2 , the excavation bucket  10  is assembled from a plurality of parts that are separately formed and then joined together, typically by welding, to assemble the bucket  10 . The parts include:
         a lip  11  that provides the ground engaging edge of the bucket;   two integrally cast hinge necks  12  and cheek members  13 , although in an alternative embodiment to that shown in the Figures, these may be formed as separate parts;   side wall members  14 ;   corner members  15 ;   a floor member  16 ; and   a roof member (not shown).       

     The lip  11  comprises a base portion  20  that extends across the width of the bucket and has a front edge  21  that forms part of the front digging edge of the bucket  10  and an opposite rear edge  22  that is joined to the floor member  16  and corner member  15 . Spaced along the front edge  21  of the lip  11  are a plurality of noses  23  to which replaceable tooth assemblies may be mounted. Adaptors  24  of such tooth assemblies are shown for example in  FIGS. 16 and 17 . The tooth assemblies also comprise points attached to these adaptors, although they are not shown in the Figures. Between each of the noses  23 , the front edge  21  of the lip  11  has recesses  25  to which replaceable wear members or ‘shrouds’  26  are assembled to provide protection for the front edge of the lip  11  against wear (see  FIGS. 16 and 17 ). 
     It is to be appreciated that although in the particular embodiment shown in the Figures the lip has six noses and five recesses, that the lip may have more or less such noses or recesses. The lip in the embodiment shown in the Figures is configured such that the noses projecting from the front edge of the lip are in a staggered formation with the central noses projecting further forward than the side noses and the recesses are correspondingly staggered but with the edge of the lip in each of the recesses remaining parallel to each other. This may be referred to in the art as a “semi-spade” arrangement. However, it is to be understood that any other suitable configuration of the noses and recesses may be incorporated into the lip. 
     The lip  11  also comprises wing members  27   a  and  27   b  which are located at opposed sides of the body  20  of the lip. When the lip  11  is assembled with the other members to form the excavation bucket  10 , the wing members  27   a,b  form part of respective side walls of the bucket, with inner and outer surfaces of the wing members forming part of the inner and outer surfaces of the bucket. The wing members  27   a,b  each project upwardly from the body  20  and extend generally between the front and rear edges  21 ,  22  of the body  20 . The wing members  27   a, b  themselves each have a forward edge  28  which extends upwardly from the front edge  21  of the lip  11  and will, in use, have a digging function. As a result, the forward edge  28  of each of the wing members  27   a,b  will be subject to wear and are accordingly provided with a wear member  29  to protect against this as shown in  FIG. 15 . The wing members  27   a, b  also each have a rearward edge  31  that faces in the opposite direction to the forward facing edge  28  and is joined to respective corner members  15  and side wall members  14  when the excavation bucket  10  is assembled. 
     Each wing member  27   a, b  also has a top joint edge  32  that extends between its respective forward and rearward facing edges  28 ,  31 . The top joint edge  32  also angles downwardly towards the body  20  of the lip as the top joint edge  32  extends from the forward to the rearward facing edges  28 ,  31  of that wing member  27   a,b . One of the cheek members  13  that is integrally cast with one of the hinge necks  12  joins to the top joint edge  32  of each respective wing member  27   a, b  via a bottom joint edge  33  of the cheek member. The cheek members  13  and hinge necks  12  thus also provide part of respective side walls of the excavation bucket  10 , with inner and outer surfaces of the cheek members  13  and hinge necks  12  forming part of the inner and outer surfaces of the bucket. The joint edge  33  of each cheek member  13  extends between forward and rearward edges  34 ,  35  of the cheek member. When the cheek members  13  are joined to their respective wing members  27   a, b  their forward edges  28 ,  34  are aligned so that they provide generally continuous forward facing side edges for the bucket  10 . As shown in  FIG. 15 , a wear member  36  is also provided to protect the forward edge  34  of respective cheek members  13  against wear. 
     The joints between the joint edges  32 ,  33  of the lip wing members and the cheek members  13  are subjected to high stresses during use of the excavation bucket  10  and are particularly liable to suffer fatigue cracking. 
     However, in the embodiment shown in the Figures, each of the wing members  27   a, b  and the cheek members  13  are shaped to have a first thicker portion  40  between inner and outer surfaces of respective wing members and cheek members forward of a second thinner portion  41 . The first thicker portion  40  of each wing member and cheek member extends rearwardly from the forward edge  28 ,  34  of that wing member/cheek member. An intermediate portion  42  tapers in thickness from the first portion  41  to the second portion  40  and the second portion then extends from the intermediate portion to the rearward edge of its respective wing member/cheek member. This shaping is shown in detail in  FIG. 8 . It has been found that the greatest concentration of stress in the joints between respective wing members and cheek members is towards their forward edges. Advantageously, by providing thicker portions in these forward regions the strength of the joint is increased without unnecessarily increasing the weight of the excavation bucket if the whole of the wing members and the cheek members were thickened. Also, the tapered intermediate portions  42  ensure a smooth flow of stress through the wing members and cheek members in use. 
     The cross-sectional shape of the surfaces of the joint edges  32 ,  33  of respective wing members  27   a, b  and cheek members  13  are substantially identical so that the inner and outer surfaces of the excavation bucket defined by the wing members and cheek members are generally continuous. It is noted, however, that the joint edge  33  of respective cheek members  13  may be provided with a ridge extending the length of the edge for added strength to the joint. 
     The wing members  27   a, b  and the cheek members  13  are each provided a recess  50  in their outer surfaces. Each recess  50  extends rearwardly from its respective forward edge  28 ,  34  of the wing member or cheek member, generally parallel to the other recess on that side of the bucket  10 . Accordingly, each recess  50  is formed in the respective thicker portion  40  of that wing member/cheek member. Each recess  50  also extends substantially parallel to the joint edge  32 ,  33  of the wing member/cheek member in which it is formed, but is spaced from its respective joint edge. The configuration of the recesses  50  also means that there is a recess either side of the joint between respective wing members and cheek members. 
     Advantageously, the recesses  50  provide weakened regions in the wing members and cheek members that preferentially deform under load so as to relieve loading in the joints between respective wing members and cheek members. That is, when stress is applied to the excavation bucket  10  in use, the recesses  50  can flex, reducing the stresses that are passed through the joints between the wing members and cheek plates. As a result, the likelihood of the joints failing during use is significantly reduced. Although in the particular embodiment shown in the Figures recesses are provided in the lip wing members and the cheek plates, it is to be understood that in other embodiments such recesses could be provided only in the wing members or only in the cheek plates. Furthermore, in other embodiments rather than recesses, other means by which weakened regions are provided in the wing members and/or cheek plates may be incorporated. However, in this respect, a particular further advantage of the recesses  50  is that they are configured to receive part of one of the wear members  29 ,  36  that are assembled with the excavation bucket  10  to protect the forward edges of the wing members and cheek members from wear. By doing so, the wear members  29 ,  36  can be formed with a thinner profile so as to reduce their weight. Furthermore, by containing part of the wear members in the recesses, the recesses provide support for the wear members against shear forces during use. This avoids the need to cut and weld shear support plates or blocks for the wear members to the outer surfaces of the bucket, as done conventionally. 
     The wear members  29 ,  36  each have an inner surface  60  that engages inner and outer surfaces of the excavation bucket when the wear member is assembled with the bucket and an opposite outer surface  61 . The wear members  29 ,  36  each comprise a wrapping portion  62  that wraps around a respective forward edge  28 ,  34  of the wing members and/or cheek members  27 ,  13  when the wear members are assembled with the bucket  10  and a leg  63  extending from the wrapping portion  62 . The leg  61  is received in one of the recesses  50  formed in the wing members and/or cheek members. The portion  64  of the inner surface  60  of each wear member defined by its leg  63  bulges so as to be appropriately received in and engage at least part of the floor  51  of one of the recesses  50 . An engaging portion in the form of a slot  65  is formed in the leg  63  of each wear member, the slot opening in the inner surface  60  of the wear member and in the distal end  66  of the leg. The slot  65  is shaped to engage a mounting formation in the form of a boss (not shown) that projects from the floor  51  of a respective recess  50 . The boss widens as it extends from the floor  51  and does not project beyond the outer surface of the wing member  27   a, b  or cheek member  13  on which it is formed. The slot  65  in the wear member is correspondingly shaped to fit over the boss. A lock  68  is inserted through an opening  69  in the outer surface  61  of the wear member  29 ,  36  to retain that wear member in its assembled condition with the excavation bucket  10 . 
     The wrapping portions  62  of the wear members  29 ,  36  are wider than their respective legs  63 . Advantageously, the wrapping portion  62  of one of the wear members (in the embodiment shown in the Figures it is the wear members  36  mounted to respective cheek members  13 , although in other embodiments it could be the wear member  29  mounted to respective wing members  27 ) extends over the joint between the wing member and the cheek member on each side of the excavation bucket at their forward edges. This helps protect the joint from wear during use and thus reduces the likelihood that the joint will fail. 
     In the claims which follow and in the preceding summary of the invention except where the context requires otherwise due to express language or necessary implication, the word “comprising” is used in the sense of “including”, that is, the features as above may be associated with further features in various embodiments of the invention. 
     Variations and modifications may be made to the parts previously described without departing from the spirit or ambit of the disclosure. For example the number and arrangement of the positioning and spacing of the ribs and supports may vary. Also in alternate forms, the ribs may be integrated into the side walls such as for example made integrally with the sheet by profiling of the sheets or by forming an integrated strengthening formation at a join between adjacent sheet panels forming the sheet. 
     Accordingly, the present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. 
     From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.