A wear member for attachment to earth working equipment

Abstract

A wear member (20) for attachment to earth working equipment (10), the wear member comprising an earth engagement section (24) and a mounting section (26). The mounting section (26) facilitates mounting of the wear member (24) to earth working equipment (10). The mounting section (26) comprises a body (34) having upper and lower faces (36 and 32) and an opening (40) formed in the upper face (36) for accepting a locking nut (56). The opening (40) comprises an insertion section and a non-release section whereby the locking nut (56) is inserted into the opening (40) through the insertion section and is thereafter rotated to the non-release section, preventing release of the locking nut (56) from the opening (40).

Description

A WEAR MEMBER FOR ATTACHMENT TO EARTH WORKING EQUIPMENTTechnical Field of the Invention

[0001] The present invention relates to wear members that are used in earth working equipment for example in the mining, earthmoving and agricultural industries. The present invention is particularly related to arrangements for releasable attachment of wear members to earth working equipment.Background of the Invention

[0002] The discussion of the background to the invention that follows is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any aspect of the discussion was part of the common general knowledge as at the priority date of the application.

[0003] Earth working equipment used in the mining, earthmoving and agricultural industries often has components that wear through engagement with bodies of earth and rock. Excavation buckets provide a good example where the leading edge of the bucket is usually formed with teeth that are subject to considerable wear through the abrasive conditions and heavy loads, including scraping and dragging loads, that the leading edge encounters during use. For this reason, earth working equipment often employs replaceable or sacrificial wear members in the parts of the equipment that are most prone to wear, so that when the wear members wear sufficiently, they can be removed and replaced with new wear members while the remainder of the equipment is still operational. The use of replaceable wear members thus enables the full life of the remainder of the equipment to be realised.

[0004] In some prior art arrangements, wear members have been attached to earth working equipment by welding. While this makes the attachment of the wear member to the earth working equipment very secure, the wear member normally has to be removed by an angle grinder and this unfortunately makes the removal of the wear members difficult and time consuming. Reattachment of new wear members by welding is also difficult and time consuming.

[0005] In other prior art arrangements, wear members have been attached by mechanical fasteners such as removable bolts. The use of bolts can make attachment of a new wear member to the earth working equipment much easier than welding, however, often removal of the bolts to remove a worn wear member can be difficult, particularly after the wear member has been in place for some time and there is corrosion or rust, or build-up that impedes disconnection.

[0006] One difficulty in replacing a wear member that has been attached to earth working equipment by removable bolts occurs when a bolt is unthreaded from the nut, because the nut is unrestrained once the bolt is fully unscrewed from the bolt and the nut can drop from the wear member and possibly be lost.

[0007] Another difficulty in removing locking bolts occurs when the wear member has worn sufficiently that the portion of the wear member that restrains the nut against rotation so that the bolt can be rotated relative to the nut to unscrew the bolt from the nut, has worn away, so that the nut can freely rotate or spin. The wear member will typically wear across a lower surface of the wear member and into an opening in which a locking nut is located. In this case, the nut and bolt will remain in threaded connection and will continue to attach the wear member to the earth working equipment, but rotating the bolt relative to the nut is not possible without gripping the nut to stop it from rotating. This introduces significant problems disconnecting a wear member from earth working equipment and requires the installation personnel to clamp the nut against rotation, such as by a wrench. This can be awkward and difficult and adds to the process of wear member replacement. Also, because this problem does not occur every time a wear member is to be replaced, the installation personnel do not know if they will encounter this problem until they actually go to unscrew the bolt. The need to clamp the nut requires extra equipment and effort and slows down the replacement process.

[0008] The present invention aims to provide arrangements for attaching wear members to earth working equipment that is different to the prior art and that provides advantages in the installation and removal of wear members to earth working equipment.Summary of the Invention

[0009] According to the present invention there is provided a wear member for attachment to earth working equipment, the wear member comprising: an earth engagement section and a mounting section, the mounting section facilitating mounting of the wear member to earth working equipment, the mounting section comprising a body having upper and lower faces, an opening formed in the upper face for accepting a locking nut, the opening comprising an insertion section and a non-release section whereby the locking nut is inserted into the opening through the insertion section and is thereafter rotated to the non-release section preventing release of the locking nut from the opening.

[0010] A wear member according to the present invention advantageously secures the locking nut in the non-release section of the opening for engagement by a bolt. The locking nut is therefore secured to the wear member while it is located in the non-release section and cannot be lost or dropped, which can otherwise frustrate installation personnel involved in installing new wear members. Once in the non-release section a bolt can be screwed into the nut to secure the wear member to the earth working equipment.

[0011] The non-release section can comprise a section of the opening that has an overhang that overlies the locking nut when the locking nut has been rotated to the nonrelease section. The overhang will prevent the locking nut from lifting out of the opening when it is engaged by a bolt. The overhang will be absent from the insertion section. The overhang can be a single section of overhang, or there can be two or more sections of overhang. In some forms of the invention, two sections of overhang are provided at diametrically opposed sections of the opening.

[0012] In some forms of the invention, opposite ends of the locking nut are inclined and the overhang of the opening has a complementary inclination so that the opposite ends of the locking nut nest against facing surfaces of the overhang in the non-release section.

[0013] Alternatively, the non-release section can comprise a tongue and groove arrangement whereby there is no engagement of the tongue and groove arrangement when the locking nut is inserted into the opening through the insertion section but there is engagement of the tongue and groove arrangement when or as the locking nut is rotated to the non-release section. The tongue is a projection and can be termed a ledge for example, or a step. The groove can be termed a channel or slot for example. The tongue can have any suitable shape to cooperate with the groove and typically the tongue will have approximately the opposite shape to the groove.

[0014] Either of the opening or the locking nut can have either of the tongue and groove, however, in some forms of the invention, the tongue is formed on the wall of the opening to project inwardly into the opening and the groove is formed in the wall of the locking nut. In some forms of the invention, a tongue extends inwardly from the wall of the opening in the non-release section and a groove is formed in the wall of the locking nut. The groove can be formed in the wall of the locking nut between upper and lower surfaces or ends of the locking nut. Alternatively, the groove can be formed in the wall of the locking nut at the upper surface. In either case, the position of the tongue or the groove in the opening is intended to be above where the lower surface of the wear member may wear to so that even if the lower surface of the wear member does wear, connection between the opening and the locking nut is not lost.

[0015] In some forms of the invention, a pair of tongues extend inwardly from the wall of the opening at diametrically opposed sections of the non-release section and the groove in the wall of the locking nut is formed to accept the pair of tongues when the locking nut is rotated to the non-release section. There can be a single groove formed in the wall of the locking nut, or two or more separate grooves that are spaced apart, can be provided.

[0016] Other arrangements are also possible. For example, a circlip can be employed to attach to one of the opening or the locking nut and the other of the opening or the locking nut can include a groove for cooperating with the circlip.

[0017] The non-release section thus secures the locking nut against release from the opening unless the locking nut is rotated in a direction back from the non-release section to the insertion section. That is, once the locking nut has been inserted into the opening through the insertion section and has been rotated to the non-release section, the nut can only be released from the opening by rotating the locking nut in the reverse direction back to the insertion section, where the locking nut can be removed from or lifted out of the opening.

[0018] In some forms of the invention, the opening is a blind opening meaning that the opening is closed opposite the insertion section and so the locking nut can only enter and exit the opening through the insertion section. In other forms of the invention, the opening is a through opening so that the opening is open opposite the insertion section. In these forms of the invention, the locking nut will still be retained within the opening once the locking nut has been rotated to the non-release section, but the locking nut can be removed from the opening through either open end of the opening once it is in the insertion section.

[0019] However, in other forms of the invention where the opening is a through opening, the opening opposite the insertion section is of a dimension that is too small for the locking nut to pass through, so that the locking nut can only enter and exit the opening through the insertion section. In these forms of the invention, the opening may be made a through opening to accommodate the free end of a bolt that is screwed into connection with the locking nut. A through opening has other benefits in that dirt or debris that enters the opening can pass through the opening without necessarily collecting within the opening.

[0020] In forms of the invention where the opening is a through opening in which the opening opposite the insertion section is of a dimension too small for the locking nut to pass through, a problem arises if the lower face of the mounting section wears sufficiently through use, that the end of the opening that has the dimension that is too small for the locking nut to pass through when the wear member is not worn, wears away and no longer forms a barrier to passage of the locking nut. In this case, despite the wear, the locking nut remains connected to the bolt and so it cannot exit the opening though the worn lower end, but if the bolt is unscrewed from the nut, to replace the wear member, then the locking nut can fall from the opening and be lost, or need to be retrieved. This is inconvenient.Accordingly, while the locking nut is secured in the non-release section, such as by the tongue and groove arrangement discussed above, the locking nut is also secured against release from the opening through the lower face of the mounting section.

[0021] The non-release section can also be configured or arranged to secure the locking nut against rotation in either direction of rotation, so that when the bolt is to be removed from screw connection with the locking nut, the locking nut is restrained against rotation so that the bolt can be rotated relative to the locking nut and unscrewed or disconnected from the locking nut. This function of securing the locking nut against rotation in either direction of rotation can be made to apply despite any wear of the wear member that occurs during use.

[0022] To secure the locking nut against rotation in a direction of rotation, the nonrelease section can include an abutment whereby a locking nut that is inserted into the opening through the insertion section can then be rotated to the non-release section and into engagement with the abutment in the non-release section. Engagement of the abutment terminates further rotation of the locking nut and so the abutment can be positioned so that the locking nut engages the abutment when the locking nut is in the correct or final position within the non-release section.

[0023] An abutment can also be positioned so that the locking nut engages the abutment when the locking nut is in the insertion section of the opening. In this form of the invention, the locking nut can be inserted into the opening through the insertion section without engaging the abutment, but the abutment is engaged when the locking nut is rotated from the non-release section to the insertion section so that the locking nut is in the correct or final position within the insertion section for removal from the insertion section. That abutment is also beneficial for the disconnecting of the bolt from the locking nut, whereby rotation of the locking nut is prevented in the insertion section once the locking nut has engaged the abutment so that then the bolt can be rotated relative to the locking nut for disengaging or unscrewing the bolt from the locking nut.

[0024] It is to be noted that a single abutment can be engaged by the locking nut when the locking nut is positioned in each of the insertion section and the non-release section. That is, rotation of the locking nut from the insertion section to the non-release section canbring one part of the locking nut into engagement with the abutment, while reverse rotation back to the insertion section can bring a different part of the locking nut into engagement with the abutment. However, alternatively, two different abutments can be provided in which a first abutment is engaged when the locking nut is rotated to the non-release section and a second abutment is engaged when the locking nut is rotated to the insertion section.

[0025] The use of one or more abutments can therefore restrain the locking nut against rotation in a first direction of rotation, for example in a direction towards the non-release section, so that a bolt can be screwed into engagement with the locking nut, or in a second or opposite direction of rotation, for example in a direction towards the insertion section from the non-release section, so that a bolt can be screwed out of engagement with the locking nut. Advantageously, this means that there is no need for the nut to be engaged by a wrench for example to restrain the locking nut from rotation. Without further restraint, the locking nut will be rotatable between the insertion section and the non-release section, but only between the two respective abutments, so that when a bolt is being screwed into connection with the locking nut the locking nut will initially rotate into engagement with one of the abutments and when the bolt is being unscrewed from the locking nut, the locking nut will rotate into engagement with the other abutment.

[0026] The or each abutment can be a projection that extends inwardly from the wall of the opening, such as in the non-release section, although it could alternatively be in a different section. In some forms of the invention, a pair of abutments are provided at diametrically opposed sections of the wall of the opening, or at least at different sections. The pair of abutments can be engaged separately depending on the direction of rotation and the location of the locking nut, ie one abutment will be engaged during rotation to the nonrelease section and the other abutment will be engaged during rotation to the insertion section.

[0027] The locking nut can be released from the opening by rotating it to the insertion section whereby it is no longer restrained to remain within the opening. The locking nut can be lifted out of the opening. Removal of the locking nut from the opening can be made with or without the bolt being attached. Accordingly, in some forms of the invention, attachment of the wear member to earth working equipment involves inserting the locking nut into theopening of the wear member, rotating the locking nut to the non-release section, placing the wear member in position relative to the earth working equipment and inserting the bolt through the earth working equipment and the wear member and screwing the bolt into the locking nut. While the locking nut remains in the non-release section, the wear member will remain secured to the earth working equipment. However, there is the possibility of the locking nut rotating in the reverse direction back to the insertion section and so to prevent this, the locking nut can additionally be restrained against reverse rotation once it has engaged the abutment in the non-release section. This restraint will prevent the locking nut from rotating inadvertently from the non-release section to the insertion section.

[0028] Accordingly, a wear member according to the invention can include an abutment that restrains the locking nut against reverse rotation from the non-release section. This abutment when combined with the other abutment of the non-release section, can secure the locking nut in the non-release section.

[0029] Where the wear member includes an abutment to restrain the nut against reverse rotation from the non-release section, the abutment can be provided by an external fitting that is inserted into the opening after the locking nut has been inserted into the opening and has been rotated to the non-release section. The external fitting can engage with the opening so that it is restrained against movement once inserted and so that it restrains the locking nut as required against rotation in the reverse direction of rotation. For this, the opening can be shaped to engage with the external fitting to locate the external fitting in place once it is inserted. For example, the opening can be shaped with flat or straight side edges for example, and the external fitting can include flat or straight side edges that sit against the flat or straight side edges of the opening once the external fitting is inserted into the opening, so that the external fitting is precluded from rotation by interaction between the respective flat or straight side edges. Other arrangements can be adopted to restrain the external fitting against movement once inserted into the opening and these can include suitable abutments (different to the straight side edges given as the example above) or could include locking pins that are inserted through the external fitting and into the locking nut.

[0030] The external fitting can engage with the locking nut in any suitable manner and for example, the external fitting can include one or more abutments to engage the locking nut in the non-release section to preclude reverse rotation of the locking nut from the nonrelease section back to the insertion section. In this form of the invention, the locking nut can be inserted into the insertion section and rotated to engage an abutment in the nonrelease section, in which that abutment is associated with the opening of the wear member. That abutment locates the locking nut in the non-release section and advantageously gives a tactile indication to an installer that the locking nut has reached the correct position in the non-release section. The external fitting can then be inserted into the opening and engage with the locking nut, or simply be positioned relative to the locking nut. The external fitting becomes effective if for any reason the locking nut tends to rotate in the reverse direction towards the insertion section, whereby the external fitting resists that rotation by engagement with the locking nut. The external fitting thus secures the locking nut in the non-release section for the duration of the location of the external fitting in the opening.

[0031] To allow the locking nut to return from the non-release section to the insertion section, the external fitting is removed and that allows the locking nut to be rotated in the reverse direction of rotation back to the insertion section where the locking nut can be removed.

[0032] The above arrangement that employs the external fitting advantageously arrests inadvertent rotation of the locking nut from the non-release section to the insertion section where the locking nut could release from the opening of the wear member and so release the wear member from connection with the earth working equipment. Also, the use of the external fitting according to different forms of the invention can be simple such as a plate form of fitting that can be dropped into place and easily removed when required.

[0033] In a plate form of the external fitting, the plate can be planar and the locking nut can be formed with one or more abutments to engage side edges of the external fitting. Alternatively, the external fitting may include one or more openings and the one or more abutments of the locking nut can extend into the one or more openings of the external fitting. In these arrangements, once the locking nut is in the non-release section of theopening, interaction of the one or more abutments with the locking nut prevents reverse rotation of the locking nut from the non-release section to the insertion section.

[0034] In other forms of the invention, the plate can include sections that are formed out of plane and that can engage with parts of the opening and the locking nut when the locking nut is in the non-release section and can prevent reverse rotation of the locking nut from the non-release section to the insertion section. In these forms of the invention, the locking nut can include one or more abutments to engage the out of plane parts of the plate and the plate can include one or more abutments to engage an abutment or abutments of the opening. In some forms of the invention, the locking nut can be shaped to provide a void within the opening once the locking nut has rotated to the non-release section and the external fitting can include an out of plane part that enters the void and that engages an abutment of the opening, so that the external fitting is prevented from reverse rotation by engagement with the one or more abutments of the opening and the locking nut is prevented from reverse rotation by engagement with the one or more abutments of the external fitting. By this arrangement, the locking nut is prevented from return rotation while the external fitting is in place.

[0035] In some forms of the invention, the plate has a planar or flat main body section and one end section, or a pair of end sections that are out of plane with the main body section. The opening of the wear member can be circular and the locking nut can have straight sides, so that once the locking nut is in the non-release section, there is a void on either side of the locking nut adjacent the straight sides. In this form of the invention, the end section, or the pair of end sections of the external fitting can extend into one or both of the voids and can engage one or more abutments associated with the opening.Brief Description of the Drawings

[0036] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which:

[0037] Figure 1 illustrates a generic form of excavator to which the present invention is relevant.

[0038] Figure 2 is a side view of a wear member according to the present invention.

[0039] Figure 3 shows the wear member of Figure 2 in perspective view from above.

[0040] Figure 4 is the same view as Figure 3, but with the component of an earth working equipment removed.

[0041] Figure 5 is a cross-sectional view of the wear member of Figure 2.

[0042] Figures 6 and 7 are front and rear views of the wear member of Figure 2 taken from above.

[0043] Figure 8 illustrates three different views of the opening of the wear member of Figure 2 with the external fitting absent, the external fitting inserted and the external fitting rotated.

[0044] Figures 9 to 12 are side, perspective and plan views of the locking nut of the invention.

[0045] Figures 13 and 14 are cross-sectional views of the locking nut of the invention located within the opening of the wear member of Figure 2.

[0046] Figures 15 to 17 are side, plan and perspective views of an external fitting according to the present invention.

[0047] Figure 18 is a cross-sectional side view of the wear member according to the present invention.

[0048] Figure 19 illustrates the wear member according to the present invention from the leading end and showing wear across the lower surface.

[0049] Figures 20 to 23 are side, perspective and top and bottom views respectively of an alternative form of locking nut.

[0050] Figure 24 is a perspective view from above of a mounting section employing locking nuts according to Figures 20 to 23.

[0051] Figures 25 to 28 are side, perspective and top and bottom views respectively of a further, alternative form of locking nut.

[0052] Figure 29 is a perspective view from above of a mounting section employing locking nuts according to Figures 25 to 28.

[0053] Figures 30 and 31 are perspective and end views respectively of an alternative form of locking nut.Detailed Description of the Drawings

[0054] A generic form of excavator 10 is shown in Figure 1. The excavator 10 includes a hydraulically controlled arm 12 and at the end of the arm 12 there is an excavation bucket 14. The bucket 14 has teeth 16 that extend from the leading end 18 of the bucket. The teeth 16 are replaceable as they are subject to significant wear during use of the bucket 14. The present invention relates to arrangements for connecting teeth to earth working equipment such as excavators 10.

[0055] Figure 2 shows a wear member 20 in side view, while Figure 3 shows the wear member 20 in perspective view from above. The wear member 20 is shown connected to a component 22 of an earth working equipment, which could be an excavation bucket for example. The component 22 is thus simply illustrative of a connection between the wear member 20 and earth working equipment, but the component 22 is not intended to represent an actual component of earth working equipment.

[0056] The wear member 20 includes an earth engagement section 24 and a mounting section 26. The section 24 is formed in a wedge shape to facilitate engagement with earth that is being excavated, for biting into the earth, or for sliding under rocks for example. The leading end 28 of the section 24 is usually the first point or line of contact with the earth during excavation and it is the leading end 28 that is most prone to wear. However, other surfaces of the wear member 20 can also wear, in particular the upper exposed surface 30, and the lower surface 32. It is thus advantageous to be able to replace the wear member 20 once it has worn to a sufficient extent.

[0057] The mounting section 26 comprises a body 34 having an upper surface 36 and the lower surface 32. Openings 38 are formed in the upper surface 36 and extend into the body 34. As shown in the cross-sectional view of Figure 5, the openings 38 extend fully through the body 34 and through the lower surface 32. However, as shown in Figure 5, the cross-section of the openings 38 varies between the upper and lower surfaces 36 and 32, so that the diameter of the opening at the upper surface 36 is greater than at the lower surface 32.

[0058] The openings 38 are provided for accepting and retaining a locking nut that is engageable by a bolt 40 (see Figure 3). Three bolts 40 are shown in Figure 3 and these releasably secure the wear member 20 to the component 22, so that when the wear member 20 has worn to a sufficient extent, the wear member 20 can be removed and replaced with a new wear member.

[0059] It is to be noted that the earth engagement section 24 and the upper surface 36 each include scalloped sections. These scalloped sections are unique to the design of the particular wear member 20 shown in the drawings, but are not relevant to the present invention and so will not be described in detail.

[0060] The openings 38 are generally circular and are shaped to allow insertion of a locking nut, followed by rotation of the locking nut. The openings 38 thus include an insertion section and a non-release section. The non-release section secures the locking nuts within the openings 38 against release from the openings 38 so that the bolts 40 can be screwed into the locking nuts to secure the component 22 to the wear member 20.

[0061] Figures 5 to 7 illustrate the insertion section and the non-release section. In Figure 5, the non-release section 41 of the opening 38 shown in cross-section comprises an inwardly extending projection, extension or tongue 42 that extends inwardly from the wall of the opening 38 about the opening for a portion of the circumference of the opening. Figure 5 shows that the tongue 42 terminates at opposite ends 44 and 46 with the end 46 forming an abutment. What is not shown in Figure 5 is that a similar tongue is formed in the wall of the opening 38 on the opposite side of the opening 38, but with the abutment 46 of the tongue 42 being located at the opposite end of the tongue 42. This arrangement can be seen in Figure 6 and more particularly in Figure 8, in which in the opening 38A, the tongue 42 is shown on one side of the opening 38A while a further tongue 48 is shown on the opposite side of the opening 38A. The tongue 48 includes an abutment 50 and each of the tongues 42, 48 and the abutments 46, 50 are generally identical other than having the opposite orientation.

[0062] Figure 8 also illustrates in relation to opening 38A, the insertion sections 52 and54, which are sections of the opening 38A which are free of any intrusion by the tongues 42 and 48. Figure 8 illustrates two other openings 38 and these will be described in more detail later herein.

[0063] The openings 38 are shaped or configured to receive a locking nut of the form shown in Figures 9 to 12. Figure 9 is a side view of the locking nut 56, while Figure 10 is a perspective view from above and Figures 11 and 12 are top and bottom views respectively.

[0064] The locking nut 56 has an opening 58 which is a threaded opening (the thread is not shown in those figures) for cooperation with the threaded shaft of a bolt 40. As shown in Figures 11 and 12, the outer periphery of the locking nut 56 is generally rectangular in plan view, with opposite long sides 60 being generally straight, and the opposite ends 62 having a slight convex curvature. As shown in Figures 9 and 10, the locking nut 56 has grooves 64 and 66 formed in the ends 62 below tabs or overhangs 84.

[0065] The grooves 64 and 66 are configured to accept and mate with the tongues 48 of the openings 38. Moreover, the insertion sections 52 and 54 facilitate entry of the locking nut 56 into an opening 38 prior to rotation of the locking nut 56. Thus, with reference to Figures 6 to 8, the opposite ends 62 of the locking nut 56 are aligned with the insertion sections 52 and 54 of the opening 38 and then the locking nut 56 can be inserted into the opening 38. The locking nut 56 can then be rotated to the position shown in the opening 38B, whereby it has been rotated through 90°. As the locking nut 56 is rotated, the tongues 42 enter the grooves 64 and 66 and as shown in Figure 8, the tongues 42 and 48 of the opening 38B are almost entirely within grooves 64 and 66 of the locking nut 56 once the locking nut 56 has reached the fully rotated position in the opening 38B.

[0066] Moreover, the sides 60 of the locking nut 56 have been rotated into engagement with the abutments 44 and 46, so that the locking nut 56 is precluded from further rotation in that direction. The locking nut 56 is thus located in the position shown in opening 38B of Figure 8, and it cannot be removed from the opening 38B by virtue of the mating engagement between the grooves 64 and 66 and the tongues 42 and 48. A cross-sectional view of the locking nut 56 located within the opening 38B is shown in Figure 13 and this shows the mating of the tongues 42 and 48 with the grooves 64 and 66 and from this figure,it is clear that the locking nut 56 cannot be lifted out of the opening 38B. The cross-sectional view of Figure 14 shows engagement of the sides 60 of the locking nut 56 with the abutments 44 and 46.

[0067] In relation to opening 38B, the locking nut 56 is free to be rotated in the reverse direction back to alignment with the insertion sections 52 and 54 so that the locking nut 56 can be removed from the opening 38B. Advantageously, the sides 60 of the locking nut 56 will engage the abutments 46 and 50 to locate the locking nut 56 aligned with the insertion sections 52 and 54.

[0068] To prevent reverse rotation of the locking nut 56 from the non-release section of the opening 38B, an external fitting in the form of a plate 70 can be employed. The plate 70 is shown in Figures 15 to 17, in which Figure 15 is a cross-sectional side view of the plate 70, Figure 16 is a top view and Figure 17 is a perspective view from above.

[0069] Figures 15 to 17 show that the plate 70 has a planar or flat main body section 72 and out of plane opposite ends 74. The plate 70 has an opening 76 which is sized to align with the opening 58 of the locking nut 56.

[0070] The plate 70 is shown fitted within the opening 38C in Figures 6 to 8. With reference to Figure 8 it can be seen in opening 38C that the ends 74 of the plate 70 extend into the voids 78 (see opening 38B) that are formed between the sides 60 of the locking nut 56 and the wall of the opening 38B in the region of the insertion sections 52 and 54. Also, the walls 80 of the plate 70 that connect the ends 74 with the main body section 72 engage with the abutments 46 and 50 of the opening 38 so that the plate 70 is precluded from rotation within the opening 38.

[0071] Further still, the walls 80 of the plate 70 engage with the sides 60 of the locking nut 56 (see Figures 11 and 12), so that if there was any tendency for the locking nut 56 to rotate back from the non-release section of opening 38B to the align with the insertion sections 52 and 54, engagement of the walls 80 with the sides 60 prevents that reverse rotation. It follows that the plate 70 cannot rotate once it is fitted into the opening 38 as shown in Figure 8, and the plate 70 thus prevents the locking nut 56 from rotating in the reverse direction.

[0072] Figure 18 is a cross sectional view of the arrangement shown in Figures 2 and 3, through one of the openings 38. In this figure, it can be seen that the bolt head 86 of the bolt 40 rests against a washer 88 that seats on a surface of the component 22 and that the threaded shaft 90 extends through an opening in the component 22 and into threaded engagement with the locking nut 56. The locking nut 56 is in the non-release section of the opening 38 (see Figure 13) and is secured against rotation as described above. The interengagement between the bolt 40 and the locking nut 56 secures the wear member 20 to the component 22. The plate 70 prevents the locking nut 56 from rotating back to the insertion section of the opening 38. When the wear member 20 is to be released from the component 22, the bolt 40 can be rotated out of engagement with the locking nut 56 to release the wear member 20 from connection with the component 22.

[0073] In the illustrated arrangement, engagement of the locking nut 56 with the abutments 46 and 50 terminates rotational movement of the locking nut 56 in the direction of rotation from the insertion section of the opening 38 to the non-release section. The plate 70 engages the sides 60 of the locking nut 56 and thus terminates rotational movement of the locking nut 56 in the reverse direction of rotation from the non-release section of the opening 38 to the insertion section. The locking nut 56 is thus prevented from any rotation when the locking nut 56 is in the non-release section of the opening 38 and the plate 70 is inserted into the opening 38 in the position shown in opening 38C of Figure 8. This confinement of the locking nut 56 is important for both engagement and disengagement of the locking nut 56 with the bolt 40. The bolt 40 can be screwed into the locking nut 56 by the locking nut 56 remaining stationary through engagement of the abutments 46 and 50 and the bolt 40 can be unscrewed from the locking nut 56 by the locking nut 56 remaining stationary through engagement of the walls 80 of the plate 70.

[0074] The ability to unscrew the bolt 40 from the locking nut 56 is important and not always provided in the prior art. Figure 19 illustrates the wear member 20 (looking towards the wear member 20 from the leading end 28) that has worn across the lower surface 32 so that the lower end of the locking nut 56 is exposed. In some prior art arrangements, the lower end of the locking nut is initially secured against rotation when the wear member is firstly installed as new, to enable the bolt to be unscrewed from the locking nut and so in those prior art arrangements, once the lower surface 32 of the wear member 20 is wornaway as shown in Figure 19, the lower end of the locking nut 56 would be free to rotate. To unscrew the bolt 40 from the locking nut 56, it then becomes necessary to grip the lower end of the locking nut 56 to prevent it from rotating. This adds a complexity to changing the wear member, particularly when there are three bolts 40 in the illustrated example. Also, once the lower surface 32 of the wear member 20 wears away, the wear of the free end of the bolt 40 can occur and often that results in the free end wearing to a sharp edge, that can be a safety hazard to personnel involved in changing the worn wear member.

[0075] However, in the present invention, the upper end of the locking nut is secured against rotation, so that if the lower surface of the wear member wears away, the locking nut is still restrained against rotation. The bolt 40 can thus be removed without needing to grip the lower end of the locking nut 56 to prevent it from rotating. This makes removal of the bolts 40 much easier and removes the potential for personnel involved in changing the worn wear member coming into contact with any sharp edges that have developed as a result of wear of the free end of the bolt 40.

[0076] The locking nut can take alternative forms, and a different form is illustrated in Figures 20 to 23. Figure 20 is a side view of the locking nut 100, while Figure 21 is a perspective view from above and Figures 22 and 23 are top and bottom views respectively. Figure 24 is a perspective view from above of a mounting section with three openings for receiving locking nuts and bolts. One of the openings is shown empty, while the middle opening shows a locking nut inserted into the opening and in the non-release position. The third opening has a locking nut inserted and in the non-release position, but the locking nut is obscured by an external fitting in the form of a plate, which operates to prevent rotation of the locking nut to the release position. The plate operates as discussed above in relation to the plate 70.

[0077] The locking nut 100 has an opening 102 which is a threaded opening (as with Figures 9 to 12, the thread is not shown in those figures) for cooperation with the threaded shaft of a bolt, such as the bolt 40 of the previous figures. As shown in Figures 22 and 23, the outer periphery of the locking nut 100 is generally rectangular in plan view, with opposite long sides 104 being generally straight, and the opposite ends 106 having a slight convex curvature.

[0078] As shown in Figures 20 and 21, the locking nut 100 has grooves 108 and 110 formed in the ends 112. The grooves are formed below tabs 114. These short tabs 114 differ from the longer tabs 84 of earlier Figures 9 to 11, but the function is generally the same, although the construction of the openings in the wear member to accept the locking nut 100 is different to the construction of the openings 38 of the wear member 20.

[0079] The openings 116 in Figure 24 are not circular like the openings 38 in Figure 4 for example, but rather, the openings 116 have straight sides 118 and curved, offset ends 120. Inboard of the openings 116 are tongues 122 (similar to the previously described tongues 48, but only one tongue is visible in Figure 24) that are received within the grooves 108 and 110 when the locking nut 100 is inserted into each opening 116 at 90° to the position shown in Figure 24. After insertion of the locking nut 100 into the opening 116, the locking nut 100 can be rotated to the position shown in Figure 24, whereby it has been rotated through 90°. As the locking nut 100 is rotated, the tongues 122 enter the grooves 108 and 110.

[0080] Moreover, the sides 104 of the locking nut 100, including the tabs 114, rotate into engagement with the abutments 124 and 126, so that the locking nut 100 is precluded from further rotation in that direction. The locking nut 100 is thus located in the position shown in opening 116A of Figure 24, and it cannot be removed from the opening 116A by virtue of the mating engagement between the grooves 108 and 110 and the tongues 122. This capture of the locking nut 100 within the opening 116A is similar to the arrangement described earlier herein in relation to the locking nut 56 being secured within the openings 38.

[0081] The locking nut 100 is free to be rotated in the reverse direction back through 90° so that the locking nut 100 can be removed from the opening 116.

[0082] To prevent reverse rotation of the locking nut 100 from the opening 116, an external fitting in the form of a plate 128 can be employed (see opening 116B in Figure 24). The plate 128 operates in the manner previously described for the plate 70 as shown in Figures 15 to 17. Indeed, the plate 128 can have the same shape as the plate 70 and cooperate with the locking nut 100.

[0083] A further different form of locking nut 130 is illustrated in Figures 25 to 29.Figure 25 is a side view of the locking nut 130, while Figure 26 is a perspective view fromabove and Figures 27 and 28 are top and bottom views respectively. Figure 29 is a perspective view from above of a mounting section with three openings for receiving locking nuts and bolts. One of the openings is shown empty, while the middle opening shows a locking nut inserted into the opening and in the non-release position. The third opening has a locking nut inserted and in the non-release position, but the locking nut is obscured by an external fitting in the form of a plate, which operates to prevent rotation of the locking nut to the release position. The plate operates as discussed above in relation to the plate 70.

[0084] The locking nut 130 has an opening 132 which is a threaded opening (as with Figures 9 to 12, the thread is not shown in those figures) for cooperation with the threaded shaft of a bolt, such as the bolt 40 of the previous figures. As shown in Figures 27 and 28, the outer periphery of the locking nut 130 is not generally rectangular in plan view as with the earlier locking nuts 56 and 100. The opposite sides 134 have two sections being a generally straight section above (in the orientation shown in the drawings) a generally curved, while the opposite ends 136 have a slight convex curvature. The straight sections are straight to cooperate with an external fitting such as disclosed earlier herein, in the form of the plate 70.

[0085] The two sections of the opposite sides 134 form overhangs 135 (see Figure 28) that are supported on a ledge or projection within an opening 140 in the mounting section 144. The cooperation between the overhangs 135 and the ledge or projection within the opening 140 supports the locking nut 130 within the opening 140 even once the bottom surface of the mounting section 144 has been worn away. This arrangement provides the same solution as described in relation to Figure 19 above to prevent the locking nut 130 from rotating when the wear member is to be changed and the bolt securing the wear member to the mounting section 144 needs to be unscrewed.

[0086] The ends 136 of the locking nut 130 are shaped to nest below an overhang, such as overhanging ledges 138 shown in the opening 140A of the body 142 of the mounting section 144 (only one overhanging ledge 138 can be seen in Figure 29, but each opening 140 includes two overhanging ledges 138 positioned opposite each other in the non-release sections of the openings 140 and separated by gaps that form the insertion sections of the openings 140), so that when the locking nut 130 is inserted into each opening 140 at 90° to the position shown in the opening 140B in Figure 29, the locking nut 130 can be rotatedthrough 90° to the position shown in the opening 140B in Figure 29. As the locking nut 130 is rotated, the ends 136 shift below the ledges 138 and the locking nut 130 is secured within the opening 132.

[0087] The ends 136 of the locking nut 130 are inclined from the top surface 146 to the bottom surface 148. The facing surfaces 150 (see Figure 29) of the overhanging ledges 138 have a similar inclination to allow the ends 136 to nest against the facing surfaces 150 of the overhanging ledges 138. The ends 136 and the facing surfaces 150 of the overhanging ledges 138 could be otherwise shaped as long as a nesting engagement can be provided when the locking nuts 130 are rotated to the position shown in the opening 1408 in Figure 29.

[0088] As with earlier embodiments, a plate 152 having the construction as shown in figures 15 to 17, can be inserted into the openings 140 (see opening 140C of Figure 29) to prevent the locking nut 130 from reverse rotation and from release from the opening 132.

[0089] A further development of the present invention is shown in Figures 30 and 31. The locking nut 140 of Figures 30 and 31 is substantially the same as the locking nut 100 of Figures 20 to 23, with the exception that the shape of the ends 142 differs.

[0090] A comparison between the locking nut 154 shown in Figure 30 and the locking nut 100 of Figure 21 reveals a substantial similarity between the respective locking nuts. However, Figure 31 shows a subtle difference in which the ends 156 each include a slope or inclination from one side of the locking nut 154 to the other side as shown by the arrow A. The facing surface of the tongue within an opening in the wear member in which the locking nut 154 is installed, is also inclined at the same inclination as the arrow A.

[0091] The inclined ends 156 and the inclined facing surface of the tongue within the wear member mate or nest together, or simply face each other when the locking nut 154 is rotated to the non-release position within the opening in the wear member and the inclination is in the opposite direction to the pitch of the thread of the opening 160.

[0092] The inclination of both the ends 156 and of the complementary inclination of the facing surface of the tongue within an opening in the wear member, is in an opposite direction to the pitch of the thread of a bolt that is threaded into the locking nut 154.Advantageously, this is expected to resist rotation of the locking nut 154 from the non-release position, such as during use of a wear member in an excavator 10 as shown in Figure 1. This further development of the present invention is expected to provide even more stability to the locking nut 154 in an in use condition.

[0093] Unless the context requires otherwise, where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components, or group thereof.

[0094] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

Claims

Claims:

1. A wear member for attachment to earth working equipment, the wear member comprising: an earth engagement section and a mounting section, the mounting section facilitating mounting of the wear member to earth working equipment, the mounting section comprising a body having upper and lower faces, an opening formed in the upper face for accepting a locking nut, the opening comprising an insertion section and a non-release section whereby the locking nut is inserted into the opening through the insertion section and is thereafter rotated to the non-release section preventing release of the locking nut from the opening.

2. A wear member according to claim 1, the non-release section comprising a section of the opening that has an overhang that overlies the locking nut when the locking nut has been rotated to the non-release section.

3. A wear member according to claim 1, the overhang comprising a single section of overhang, or two or more sections of overhang.

4. A wear member according to claim 3, the overhang comprising two sections that are provided at diametrically opposed sections of the opening.

5. A wear member according to any one of claims 2 to 4, opposite ends of the locking nut being inclined and the overhang of the opening having a complementary inclination so that the opposite ends of the locking nut nest against facing surfaces of the overhang in the non-release section.

6. A wear member according to claim 1, the non-release section comprising a tongue and groove arrangement whereby there is no engagement of the tongue and groove arrangement when the locking nut is inserted into the opening through the insertionsection but there is engagement of the tongue and groove arrangement when or as the locking nut is rotated to the non-release section.

7. A wear member according to claim 6, the tongue comprising a projection and the groove comprising a channel or slot.

8. A wear member according to claim 6 or 7 , the tongue being formed on a wall of the opening to project inwardly into the opening and the groove being formed in a wall of the locking nut.

9. A wear member according to claim 8, the groove being formed in the wall of the locking nut between upper and lower surfaces or ends of the locking nut.

10. A wear member according to claim 5, the tongue and groove arrangement comprising a pair of tongues extending inwardly from a wall of the opening at diametrically opposed sections of the non-release section and a groove in a wall of the locking nut being formed to accept the pair of tongues when the locking nut is rotated to the non-release section.

11. A wear member according to any one of claims 1 to 10, the opening being a blind opening which is closed opposite the insertion section.

12. A wear member according to any one of claims 1 to 910 the opening being a through opening which is open opposite the insertion section.

13. A wear member according to claim 12, the opening opposite the insertion section is of a dimension that is too small for the locking nut to pass through.

14. A wear member according to any one of claims 1 to 13, the non-release section being configured or arranged to secure the locking nut against rotation in either direction of rotation.

15. A wear member according to claim 14, the non-release section comprising an abutment whereby a locking nut that is inserted into the opening through the insertion section can then be rotated to the non-release section and into engagement with the abutment in the non-release section.

16. A wear member according to any one of claims 1 to 15, comprising an abutment positioned for engagement with the locking nut when the locking nut is in the insertion section of the opening.

17. A wear member according to claim 16, the abutment comprising a projection that extends inwardly from the wall of the opening.

18. A wear member according to claim 16, comprising two abutments in which a first of the abutments is engaged when the locking nut is rotated to the non-release section and a second of the abutments is engaged when the locking nut is rotated to the insertion section.

19. A wear member according to claim 18, the abutments being at diametrically opposed sections of the wall of the opening.

20. A wear member according to any one of claims 1 to 19, comprising an abutment that restrains the locking nut against reverse rotation from the non-release section.

21. A wear member according to claim 20, the abutment comprising an external fitting that is inserted into the opening after the locking nut has been inserted into the opening and has been rotated to the non-release section.

22. A wear member according to claim 21, the external fitting engaging with the opening so that it is restrained against movement once inserted and so that it restrains the locking nut against rotation in the reverse direction of rotation.

23. A wear member according to claim 21 or 22, the opening being shaped to engage with the external fitting to locate the external fitting in place once it is inserted.

24. A wear member according to claim 23, the opening comprising flat or straight side edges and the external fitting comprising flat or straight side edges that sit against the flat or straight side edges of the opening once the external fitting is inserted into the opening25. A wear member according to any one of claims 21 to 24, the external fitting comprising one or more abutments to engage the locking nut in the non-releasesection to preclude reverse rotation of the locking nut from the non-release section back to the insertion section.

26. A wear member according to any one of claims 21 to 25, the external fitting being formed from plate (metal or plastic), and the plate being planar and the locking nut being formed with one or more abutments to engage side edges of the external fitting.

27. A wear member according to claim 26, the external fitting being formed from plate (metal or plastic), and the plate being planar comprising one or more openings and the one or more abutments of the locking nut extending into the one or more openings of the external fitting when the locking nut is in the non-release section of the opening.

28. A wear member according to claim 21, the plate comprising sections that are formed out of plane and that can engage with parts of the opening and the locking nut when the locking nut is in the non-release section to prevent reverse rotation of the locking nut from the non-release section to the insertion section.

29. A wear member according to claim 28, the locking nut comprising one or more abutments to engage the out of plane parts of the plate and the plate can include one or more abutments to engage an abutment or abutments of the opening.

30. A wear member according to claim 28 or 29, the locking nut being shaped to provide a void within the opening once the locking nut has rotated to the non-release section and the external fitting comprising an out of plane part that enters the void and that engages an abutment of the opening, so that the external fitting is prevented from reverse rotation by engagement with the one or more abutments of the opening and the locking nut is prevented from reverse rotation by engagement with the one or more abutments of the external fitting.

31. A wear member according to any one of claims 28 to 30, the plate comprising a planar or flat main body section and one end section, or a pair of end sections that are out of plane with the main body section.

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