AU2015100447A4 - Adaptor and tooth assembly - Google Patents

Abstract

A tooth and adaptor assembly (10) for use on earthmoving machinery is provided. The assembly comprises an adaptor (12) configured to be mounted to a leading edge of a ground engaging component of the earth moving machinery, the adaptor having 5 an adaptor aperture (28) extending from a side surface of the adaptor at least partially into the adaptor. Furthermore, a tooth (36) is adapted to be received over a leading part of the adaptor, and to be releasably secured thereto, with the tooth having a sidewall defining a first aperture (60) which, when the tooth is received by the adaptor (28), is aligned with the adaptor aperture thereby to form a locking 10 passage. A coupling pin (30) having an engaging key is shaped and sized to be received in the locking passage. Finally, a retainer insert (34) is provided to be received in a pocket within at least one of the adaptor's side surface and the sidewall of the tooth, the retainer insert having a key receiving formation to interact with the engaging key of the coupling pin in order for the coupling pin, once received in the 15 locking passage, to rotate the retainer insert in the pocket to a locked position, in which locked position the coupling pin is secured in the locking passage with the tooth being secured over the leading part of the adaptor. co~ /c coo "It 1 (D ,~777 0 CO (D (D LO)

Description

1 Adaptor and tooth assembly Field of the invention The invention relates to an excavator tool, and more particularly, an adaptor and tooth assembly, typically a single pin adaptor and tooth assembly, for mounting 5 to the leading edge of a bucket fitted to an excavator, front end loader, or other item of material handling equipment. The invention may further extend to a multiple pin adaptor and tooth assembly. Background of the invention Excavators, front end loader and other digging mining equipment typically has 10 a bucket used to dig and/or scoop up materials during operation. The lip of a bucket forms an edge, that may be beveled, and is used to dig into the particular material. As digging, excavating and moving materials easily abrade the bucket's edge away, this type of digging equipment is provided with protective wear members that could be periodically replaced. Protective wear members may take the form of tooth and 15 adaptor assemblies, in that teeth are fitted through the use of adaptors to the edges of buckets of excavators, front end loaders, and other items of mining equipment. The teeth are then the members subjected to conditions of impact and abrasion, so much so that in extreme conditions the teeth may need to be replaced on a daily basis. In highly abrasive working environments the tooth may need replacing every 20 shift whereas the adaptor connecting the tooth to the bucket might need replacing only every 1000 shifts or more. The tooth and adaptor assembly thus needs to have certain characteristics in order to function effectively. Firstly, the tooth itself needs to protect the adaptor from damage so that the adaptor itself does not need to be regularly replaced due to 25 inadvertent wear on the adaptor. For this reason it is important that the tooth does not become dislodged from the adaptor. Were this to occur, the item of machinery would be out of commission for a lengthy period of time since the adaptor would need to be removed and replaced. As replacement includes welding the adaptor in place on the bucket edge, this is a far longer process than replacement of the tooth 30 itself.

2 A second requirement of the tooth and adaptor assembly is that the tooth must be relatively easily replaced. Thus, the locking mechanism which holds the tooth onto the adaptor needs to be easily removed or dismantled, although it should still ensure that the tooth does not inadvertently become displaced from the adaptor. In other 5 words, the locking mechanism, once in position, must not become dislodged during normal use. Many different types of locking mechanisms have been proposed, some of which are more effective than others, and some of which suffer from distinct disadvantages. One such disadvantage is that the locking mechanism itself wears, or 10 becomes bent or damaged during normal use of the machine, which either causes the locking mechanism to become dislodged, or can result in the locking mechanism only being removable with a great deal of difficulty. It is thus desirable that, once in place, the locking mechanism is protected from damage and wear. However, the locking mechanism must still be easily accessible so that when it is necessary to 15 remove the tooth from the adaptor, the locking mechanism should be easily removed. A further important feature of the ideal locking mechanism is that it should not cause wear to the adaptor itself. This is important since the adaptor is designed to remain in position on the item of machinery for a considerable period of time, while the locking mechanism will be used with many teeth. 20 If wear to the adaptor occurs, such wear tends to loosen the engagement between the locking mechanism and the adaptor which can in turn cause play in the connection between the tooth and the adaptor or can allow the locking mechanism to become dislodged from the adaptor resulting in the aforementioned problem of the tooth falling off the adaptor or the locking mechanism being damaged. 25 In summary, it is important that the locking mechanism causes minimum wear to the adaptor, is easy to install and remove, does not itself become damaged in normal use, and does not inadvertently become dislodged from the assembly. Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any 30 jurisdiction or that this prior art could reasonably be expected to be understood, 3 regarded as relevant, and/or combined with other pieces of prior art by a skilled person in the art. Summary of the invention According to the invention there is provided a tooth and adaptor assembly for 5 use on earthmoving machinery, the assembly comprising: an adaptor configured to be mounted to a leading edge of a ground engaging component of the earth moving machinery, the adaptor having an adaptor aperture extending from a side surface of the adaptor at least partially into the adaptor; 10 a tooth adapted to be received over a leading part of the adaptor, and to be releasably secured thereto, the tooth having a sidewall defining a first aperture which, when the tooth is received by the adaptor, is aligned with the adaptor aperture thereby to form a locking passage; a coupling pin, shaped and sized to be received in the locking passage, 15 the coupling pin comprising an engaging key; and a retainer insert to be received in a pocket within at least one of the adaptor's side surface and the sidewall of the tooth, the retainer insert having a key receiving formation to interact with the engaging key of the coupling pin in order for the coupling pin, once received in the locking passage, to rotate the retainer insert in 20 the pocket to a locked position, in which locked position the coupling pin is secured in the locking passage with the tooth being secured over the leading part of the adaptor. The pocket may have a locking formation, and the retainer insert may have a complementary locking formation to engage with the locking formation of the pocket once the retainer insert is in the locked position, wherein the combination of the 25 locking formations of the pocket and retainer insert restricts the rotation of the retainer insert in the pocket thereby securing the coupling pin in the locking passage. The adaptor aperture may extend through the adaptor from the side surface to an opposing side surface.

4 The pocket may be defined by one or both of the adaptor's side surface and the sidewall of the tooth. The first aperture defined in the sidewall of the tooth may further define a keyway configured to allow the engaging key of the coupling pin to pass through the 5 sidewall and to be received by the key receiving formation of the retainer insert, once the retainer insert is received in the pocket and the key receiving formation is aligned with the keyway. Typically, the retainer insert is an annular insert. The tooth may be configured to define on the inner side of the sidewall, around 10 the keyway aperture, a recess which forms the pocket. The recess may be annular. Additionally, the side surface of the adaptor surrounding the adaptor aperture may have a raised seat which defines one side of the pocket. Alternatively, the side surface of the adaptor may define a recess which forms the pocket. The recess may be annular. The inner side of the sidewall of the tooth 15 surrounding the keyway aperture may have a raised seat which defines one side of the pocket. The pocket, in particular the raised seat, limits the movement of the retainer insert to rotation. Additionally, the pocket, in particular the raised seat, limits the lateral movement of the coupling pin. 20 The key receiving formation of the retainer insert may be a slot that extends through the retainer insert. The engaging key of the coupling pin may extend as a protrusion from the coupling pin. Alternatively, the engaging key is a channel down at least a portion of the coupling pin, while the key receiving formation is a protrusion that engages the 25 channel forming the engaging key. The coupling pin may additionally comprise a guide arm located at one end of the coupling pin. In turn, the outer side of the tooth's sidewall may define, surrounding the keyway aperture, a recessed guide which in use receives, guides 5 and limits the rotation of the guide arm of the coupling pin from an unlocked position to the locked position. The locking formation of the pocket and the complementary locking formation of the retainer insert may be respective male-female connections, or vice versa. For 5 example, the locking formation of the pocket may be one or more locking depressions or notches defined as part of the recess, in which case the complementary locking formation of the retainer insert is one or more extrusions, notches or corners. Alternatively, the locking formation of the pocket may be one or more extrusions, notches or corners protruding into the recess, in which case the 10 complementary locking formation of the retainer insert is one or more complementary depressions or notches. The tooth and adaptor assembly may extend to having the locking arrangement defined above in two opposing sides of the assembly. As used herein, except where the context requires otherwise, the term 15 "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps. Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the 20 following description, given by way of example and with reference to the accompanying drawings. Brief description of the drawings These and further features of the invention will be made apparent from the description of a preferred embodiment thereof, given below by way of example. In the 25 description reference is made in the accompanying drawings but the specific features shown in the drawings should not be construed as limiting on the invention. Figure 1 shows a perspective side view of a tooth and adaptor assembly in disassembled condition depicting the various components of the assembly, in accordance with an example embodiment of the invention, 6 Figure 2 shows a side view of only an adaptor which forms part of the assembly depicted in Figure 1; Figure 3 shows a cross sectional view along line A-A of the adaptor depicted in Figure 2; 5 Figure 4 shows a cross sectional view along line B-B of a cover element which forms part of the assembly depicted in Figure 1; Figure 5 shows a cross sectional view along line C-C of a tooth which forms part of the assembly depicted in Figure 1; Figure 6 shows the cross sectional view of Figure 5 but now with a retainer 10 insert received in a recess defined by the tooth of Figure 1; Figure 7 shows a view in the direction of arrow D of the tooth depicted in Figure 1; Figures 8a and 8b show different embodiments of retainer inserts that may be used with the assembly depicted in Figure 1; 15 Figure 9 shows an enlarged perspective view of a coupling pin depicted in the assembly of Figure 1; Figure 10 shows a perspective view of the cover member and adaptor depicted in Figure 1 during a first step of assembly; Figure 11 shows a perspective view of the cover member, adaptor, retainer 20 insert and tooth depicted in Figure 1 during a further step of assembly; Figure 12 shows a perspective view of the components in Figure 11 together with the coupling pin of Figure 9 in assembled form; Figure 13 shows a cross sectional view along line E-E of only the adaptor and tooth as depicted in Figure 12; 25 Figure 14 shows a cross sectional view of the adaptor, tooth, coupling pin and retainer insert as depicted in Figure 13; 7 Figure 15 shows the interaction between only the coupling pin and retainer insert in assembled form as depicted in Figure 12 and Figure 14; Figures 16a and 16b show opposing partial side views of the interaction between one of the sidewalls of the tooth, in particular a recess forming a pocket to 5 receive the retainer insert on the inner side of the sidewall and a recessed guide on an outer side of the sidewall, together with the coupling pin and the retainer insert, in an initial arrangement prior to rotation of the coupling pin; Figures 17a and 17b show the interaction between formations in the sidewall, the tooth, the coupling pin and the retainer insert as depicted in Figures 16a and 16b 10 in a further arrangement prior to assembly; Figures 18a and 18b show the interaction between formations in the sidewall, the tooth, the coupling pin and the retainer insert as depicted in Figures 16a and 16b once the coupling pin is locked in place and the tooth is secured to the adaptor; and Figure 19 shows a further example embodiment of a coupling pin to be used 15 with a tooth and adaptor assembly. Detailed description of the embodiments Referring initially to Figures 1 and 2, a tooth and adaptor assembly 10 includes an adaptor 12 having a nose 14 formed on the front end thereof and a u-shaped recess 16 formed in the rear side thereof. The u-shaped recess 16 is shaped to 20 receive the front or leading edge of an item of equipment with which the assembly 10 is to be used. For example, the item of equipment may be a ground engaging component such as an excavator bucket, scraper blade, or various other items of equipment well known in the art. Typically the u-shaped recess 16 is secured to the front or leading edge of the item of equipment by means of welding. 25 The nose 14 has a top surface 18, a lower surface 20, a front end 22, and first and second side surfaces 24 and 26. In this example embodiment, an aperture, also called the adaptor aperture 28, extends through the nose 14, from one side of the nose 14 to the other. The adaptor aperture 28 forms part of a locking passage, which is to receive a coupling pin 30 and engages the pin in the manner described below.

8 In this example embodiment, the adaptor aperture 28 has a circular cross-section and as is apparent from Figure 3, it is frustoconical in shape, having a larger diameter at the first side surface 24 which decreases towards the second side surface 26. 5 It will be apparent to those skilled in the art that although certain benefits derive from the coupling pin 30 being frustoconical in shape, this shape is not necessary for the working of the assembly. For example, the coupling pin may also be cylindrical in shape. With specific reference to Figure 2, defined by the first side surface 24 and 10 surrounding the entry point of the adaptor aperture 28, is a raised seat 32 with which a retainer insert 34, described in more detail below and visible in Figure 1, interacts during locking of a tooth 36 on the adaptor 12. The seat 32 gradually extends from a portion of the nose 14 proximate the u-shaped recess 16, with the seat 32 terminating in a shoulder 38 towards the front end 22 of the nose 14. 15 Each of the first and second side surfaces 24 and 26 of the nose 14 also defines grooves or channels 40 running partially in alignment with the top surface 18 of the nose 14 and extending towards the u-shaped recess 16. These grooves 40 receive in use a cover member 42. The cover member 42 is best shown in Figures 1 and 4 to comprise a shallow 20 u-shaped bracket with complementary grooves or channels 44 defined by opposing side walls. The complementary grooves 44 allow the cover member 42 snugly to fit over an upper portion of the adaptor 12. It is assembled to the adaptor 12 by sliding the cover member 42 over the adaptor 12 with the complementary grooves engaging and guiding the translation of the cover member 42 over the adaptor 12. The cover 25 member 42 is to be assembled to the adaptor 12 prior to assembling the tooth 36 over the front end 22 of the nose 14. The cover member 42 serves to protect the rear and upper part of the adaptor 12 from wear and damage during use. The cover member 42 is typically not replaced each time the tooth 36 is replaced. The tooth 36 is now described with reference to Figures 1 and 5 to 7. In order 30 to ensure durability and as the tooth 36 is the wear element in the assembly 10, the 9 tooth 36 is formed of a hard wear-resistant material. It includes an upper wall 46, a lower wall 48, a first and second sidewall 50 and 52, and a front end 54. The tooth 36 has a rear end 56 with an opening therein. The opening leads to a cavity 58 which is shaped and sized to receive the nose 14 of the adaptor 12. 5 In this example embodiment, the first and second sidewalls 50 and 52 of the tooth 36 each defines an aperture 60 and 62, which, together with the adaptor aperture 28, form the locking passage for the coupling pin 30. In order to align and provide passage for the coupling pin 30, the aperture 60 defined in the first sidewall 50 has a larger diameter than the aperture 62 defined in the second sidewall 52, 10 which is only to receive a tip of the coupling pin 30. The first sidewall 50 defines a keyway 64 as a side slot to the aperture 60, while the inwardly facing (inner) side of the first sidewall 50 defines a recess 66 shaped and sized to receive, at least part of, the retainer insert 34 in use. In this example embodiment the recess 66 is annular but may shaped differently. As is 15 apparent from Figures 5 and 6, the annular recess 66 is an extension of the aperture 60 on the inside of the tooth 36. Along the outer periphery of the annular recess 66, defined by the inner side of the first sidewall 50, is one or more locking formations, shown in Figures 5 and 6 as three locking depressions 68. Also defined by the inner side of the sidewall 50 and extending from the end of the annular recess 66 closest 20 to the front end 54 of the tooth 36 is a shallow hollow 70 to receive the shoulder 38 of the adaptor 12 in use. The shoulder 38 may, but need not, abut the hollow 70 once the assembly is assembled. The combination of the hollow 70 and shoulder 38 ensures a good fit between the tooth 36 and the adaptor 12. The outer surface of the first sidewall 50, with reference now to Figure 7 in 25 particular, defines a depression around only a portion of the periphery of the sidewall defining the aperture 60, starting at the keyway 64. This depression forms a recessed guide 72 adjacent the aperture 60 which assists in the assembling of the coupling pin 30, tooth 36 and adaptor 12, as will be described in more detail below. In Figure 8a, the retainer insert 34 as originally depicted in Figure 1, is shown 30 to comprise a ring 74, annular in this embodiment to fit in the annular recess 66, and having a locking formation 76 and a key receiving formation 78. In this example 10 embodiment the key receiving formation is an inner key seat 78, in particular a slot that extends through the entire ring 74 resulting in the retainer insert 34 having a semi-circle shape. The key receiving formation 78 may also be shallow, not extending through the entire ring 74. Another example embodiment of a retainer 5 insert 134 is shown in Figure 8b, in which the retainer insert also has a key receiving formation 178 and a locking formation 176 which comprises three extrusions that fit into the three locking depressions 68 defined in the annular recess 66. The retainer insert 34 is typically manufactured from a solid, semi-solid, composite or elastic material and may be differently shaped in some embodiment to 10 allow snug fit in the recess. Turning to Figure 9, the coupling pin 30 has an elongate body and is frustoconical in shape. The coupling pin 30 is shaped and sized to be received in the locking passage defined by the aligned and co-extending first and second apertures 60 and 62 of the tooth 36 and the adaptor aperture 28 of the nose 14 of the adaptor 15 12. The coupling pin 30 is typically made from a hard, high strength, wear resistant plastics material such as, for example, neoprene rubber. Other similar polymeric materials may be used. In this example embodiment, a first end 80 of the coupling pin 30 has a reduced diameter, while a second end 82 defines an engagement formation 84, 20 which may be a cavity or a boss to receive a tool thereby allowing a user to rotate the coupling pin 30 along its longitudinal axis while in use. The engagement formation 84 may be of any suitable shape and size to allow such a tool to engage and rotate the pin 30. The coupling pin 30 also has an engaging key 86 that extends as a protrusion 25 from the frustoconical side of the pin 30, the key 86 being displaced from the second end 82 of the pin 30 to allow receipt in the recess 66. The coupling pin 30 may also have a guide arm 88 which is integral and co planar with the second end 82 of the coupling pin 30. The guide arm 88 is received, in use, in the recessed guide 72, which guides and limits the rotation of the guide arm 11 88 within the recessed guide 72 between a first and unlocked position to a second and locked position. Further features and the operation of the tooth and adaptor assembly 10 are now described with particular reference to Figures 10 to 18. As already mentioned 5 above, when assembling the tooth and adaptor assembly 10 to a front or leading edge of a piece of equipment, the adaptor 12 is typically first secured to the edge, e.g., by means of welding. Next and as best seen in Figures 10 and 11, the cover member 42 is placed over the upper part of the adaptor 12 and the respective complementary grooves 40 and 44 of the adaptor 12 and cover member 42 are 10 aligned to enable the cover member 42 to slide into position on the upper part of the nose 14 of the adaptor 12. Once in position, the retainer insert 34 is either already installed or is installed in the annular recess 66 (see Figures 5 and 6). During installation of the retainer insert 34 the inner key seat 78 of the retainer insert 34 is aligned with the keyway 64 15 defined in the first sidewall 50 of the tooth 36. This will allow the engaging key 86 of the coupling pin 30 to pass through the sidewall 50 of the tooth 36 and rest within the key seat 78 during assembly. The cavity 58 of the tooth 36 then receives the nose 14 (or leading part) of the adaptor 12. The front end 22 of the nose 14 abuts or rests against the end wall of the 20 cavity 58, while the shoulder 38 of the seat 32 lies adjacent or within to the shallow hollow 70 defined in the inner side of the first sidewall 50 of the tooth 36. As is best shown in Figures 13 and 14, defined between the seat 32 of the nose 14 of the adaptor 12 and the inner side of the first sidewall 50 of the tooth 36 (which defines the annular recess 66) is a pocket 90. The pocket 90 is a cavity that 25 receives the retainer insert 34 in use. In this example embodiment where the retainer insert 34 is manufactured from a solid material, the pocket 90 is shaped and sized for the retainer insert 34 to be snugly held therein, while its shape and size is not hampering its rotation. It will however be appreciated that the pocket 90 and retainer insert 34 may be 30 shaped and sized, and the retainer insert 34 made from an appropriate material, to 12 allow the retainer insert 34 only to be rotatable when in a compressed form. For example, in cases where the retainer insert 34 is made from a semi-solid, composite or elastic material, it may be necessary to apply force to the coupling pin 30 during insertion thereby to compress the retainer insert 34. When compressed, this retainer 5 insert has a decreased thickness, which will allow for its rotation in the pocket 90. It will be appreciated that in such an example, the key receiving formation defined by the retainer insert may be a depression which is deep enough to receive the engaging key 86 of the coupling pin 30 thereby to allow rotation of the retainer insert, but shallow enough to enable compression of the retainer insert. 10 Although the pocket 90 is shown to be defined between the raised seat 32 of the nose 14 of the adaptor and the annular recess 66 defined by the first sidewall 50 of the tooth 36, it will be appreciated by those skilled in the art, that the pocket 90 could be defined by corresponding and aligned recesses defined by both the first side surface 24 of the nose 14 and the inner side of the first sidewall 50 of the tooth 15 36, or alternatively between a recess defined by the first side surface 24 of the nose 14 and a seat, possibly a raised seat, defined on the inner side of the first sidewall 50 of the tooth 36. In each of these scenarios, the aperture 60 defined in the first sidewall 50 of the tooth 36 is to have a keyway 64 to allow the engaging key 86 of the coupling pin 30 to pass through and settle in the key seat 78 of the retainer insert 34, 20 as already described above. In Figure 14, the frustoconical shape of the adaptor aperture 28 of the nose 14 of the adaptor 12 is shown to form, with the aligned apertures 60 and 62 of the first and second sidewalls 50 and 52, a locking passage, which is in itself frustoconical. This locking passage, as mentioned, is shaped and sized to receive the coupling pin 25 30, as shown in Figure 14. The engaging key 86 is specifically shaped and sized, and located on the shaft of the coupling pin 30, both to fit in the key seat 78 of the retainer insert 34 and to be properly positioned in the pocket 90. In particular, in this example embodiment, the first end 80 of the coupling pin 30 rests within the second aperture 62 of the tooth 36, while the second end 82 is, in turn, received in the first 30 aperture 60, with the guide arm 88 being rotatable within the recessed guide 72.

13 The interaction between the key seat 78 of the retainer insert 34 and the engaging key 86 of the coupling pin 30 is best shown in Figure 15. In this particular example embodiment of the invention, the key seat 78 is a slot in the retainer insert 34 (i.e. a female member) and the engaging key 86 is a protrusion or arm on the 5 coupling pin 30 (i.e. a male member). The final steps of assembly, i.e. locking the coupling pin 30 in position with relation to the adaptor 12 and tooth 36, is now described with reference to Figures 16a to Fig 18b. The initial position of the coupling pin 30 after insertion into the locking 10 passage is shown by Figures 16a and 16b, from which it is evident that the retainer insert 34 is received in the annular recess 66 forming the pocket 90, with its key seat 78 being aligned with the keyway 64 of the aperture 60. This is the unlock position. In this position, the locking formation 76 of the retainer insert 34 is received in a corresponding locking depression 68 of the annular recess 66, thereby ensuring that 15 the retainer insert 34 does not move out of position. When the coupling pin 30 is inserted, the engaging key 86 passes through the keyway 64 to settle in the key seat 78 of the retainer insert 34. The guide arm 88 is off-set form the engaging key 86 in order for the guide arm 88 to be received by and positioned on one end of the recessed guide 72. 20 Figures 17a and 17b show the rotation of the coupling pin 30 within the locking passage. A user makes use of a tool to engage the engagement formation 84 of the coupling pin 30 thereby to rotate it along its longitudinal axis. The recessed guide 72 limits the direction of rotation of the coupling pin 30. Once the engaging key 86 is received by the key seat 78 of the retainer insert 34, the recessed guide 72 limits the 25 movement of the coupling pin 30 to only rotation within the locking passage during mounting and extraction, as lateral movement of the coupling pin 30 is restricted. During rotation of the coupling pin 30 in a clockwise direction, the engaging key 86 of the coupling pin 30 interacts with the key seat 78 of the retainer insert 34 thereby to rotate the retainer insert 34 together with the coupling pin 30. This action 30 results in the locking formations 76 of the retainer insert 34 being moved from their corresponding locking depressions 68. During this step the formations 76 may be 14 deformed or compressed so that the retainer insert 34 is able to rotate. Also, once the engaging key 86 has been rotated beyond the keyway 64 of the aperture 60, the coupling pin 30 cannot be removed from the assembly 10 as the engaging key 86 is retained in the pocket 90. 5 The coupling pin 30 is shown in Figures 18a and 18b to be rotated until the guide arm 88 has moved through the arc provided by the recessed guide 72. In this position, the second and locked position, the complementary locking formation 76 and locking depression 68 lock the retainer insert 34 in position in the recess 66 and pocket 90. In the event that the locking formation 76 deformed or compressed during 10 rotation, it will relax into a decompressed form in which it presses into a depression 68. In this locked position, both the engaging key 86 of the coupling pin 30 and the key seat 78 of the retainer insert 34 have been rotated beyond the keyway 64. As the retainer insert 34, which holds the engaging key 86, is also locked in position in the pocket 90 through the complementary locking arrangements, the coupling pin 30 is 15 secured in place and cannot rotate within the pocket unless turned with the tool. Without rotation to the first unlocked position, the coupling pin 30 can also not be removed from the assembly 10. Thus, in the locked position, the coupling pin 30 and retainer insert 34 secure the tooth 36 in position over the nose 14 of the adaptor 12. It is apparent from the above that the complementary locking formations are 20 designed to locate in and engage with each other to secure the retainer insert 34 in the locked position in the pocket 90, and thereby locking the coupling pin 30 in the locking passage of the assembly. As already mentioned, it follows that the complementary locking formations of the pocket 90 and the retainer insert 34 may have different structures provided that the elements are secured in position. 25 Also, it will be appreciated that in other example embodiments, the engaging key of the coupling pin 30 and the corresponding keyway 64 of the tooth 36 and key receiving formation of the retainer insert 34 could be any appropriate formation that would allow engagement and interaction between the parts, thereby to allow rotation of the retainer insert 34 between a first unlocked position and a second, locked 30 position. For example, and as shown in Figure 19, a further example embodiment of a coupling pin 130 is shown. For reasons of conciseness, only features that differ 15 from the coupling pin 30 described above will be explained. The coupling pin 130 defines as the engaging key 186 a channel 190, which could be a slot or a cam, that runs along a middle portion of the coupling pin 130. The channel 190 is typically chamfered on its end 192 proximate a first end 180 of the coupling pin 130, while it 5 terminates on the other end with the channel running parallel to a second end 182 of the coupling pin 130, as indicated by reference numeral 194. This channel 190 is shaped and sized to engage the key receiving formation of the retainer insert, which may be a cam follower in one embodiment. The terminating end 194 of the channel 190 restricts the lateral movement of the coupling pin and ensures that the coupling 10 pin does not disengage from the retainer insert. As the coupling pin 130 is placed in the locking passage, the chamfered end 192 of the channel 190 receives the key receiving formation of the retainer insert. During assembly the coupling pin 130 is rotated, and due to the engagement between the channel and the key receiving formation, the retainer insert rotates with 15 the coupling pin 130, until the retainer insert is locked in position in the pocket through the locking arrangements discussed above. In a different embodiment of the invention, the adaptor aperture need not extend through the nose 14 of the adaptor 12. For example, the adaptor aperture may be a blind adaptor aperture that extend from either the first or second side 20 surface at least partially into the adaptor. The adaptor aperture will then form, together with an aperture defined in the corresponding sidewall of the tooth, a locking passage. Similarly, the coupling pin will be shaped and sized to be snugly received in this shorter locking passage and will interact with a retainer insert received in a pocket defined by either one or both of the side surface of the adaptor and the 25 corresponding inner side of the tooth sidewall. The invention may also extend to an adaptor that defines in two opposing sides thereof blind adaptor apertures that respectively extend from the first and second side surfaces of the adaptor at least partially into the adaptor. It will be appreciated by a person skilled in the art that although, in such an example 30 embodiment, two coupling pins will be needed and apertures will need to be defined in opposing side walls of the tooth, most of the other features of the locking 16 arrangements of this embodiment are to remain the same as those described above with reference to the drawings. The features of the invention as described above, in particular with reference to the drawings, allow not only for the coupling pin to securely lock the tooth 36 to the 5 adaptor 12, but also for the relatively easy insertion and removal of the coupling pin from the locking passage, enabling quick and efficient replacement of the teeth on a regular basis. In the embodiment where the pocket is defined by a recess 66 in the sidewall of the tooth 36 (rather than in the adaptor 12) and with the coupling pin 30 snugly 10 fitting into the adaptor aperture and locking passage, the assembly has the benefit of restricting any wear caused by the coupling pin abrading within the recess to the tooth, and not the adaptor. Since the tooth is the replaceable part, not the adaptor, any wear that might occur over the short period within which the tooth is in use is somewhat irrelevant since the tooth will be replaced fairly frequently. It is thus the 15 worn part that will be discarded. It is envisaged that the coupling pin itself will be replaced reasonably frequently, if not every time the tooth is replaced. Providing a snug fitting coupling pin 30 in the locking passage has a number of advantages. One such advantage is that during assembly of the tooth and adaptor assembly 10 the coupling pin is pressed and received by the passage to the extent 20 that any lateral movement of the coupling pin relative to the tooth or the adaptor is prevented or substantially limited. In other words, the use of the retainer insert in combination with the coupling pin stabilises the coupling pin in position. Bending of the coupling pin in this configuration is unlikely, thereby limiting problems in relation to disassembling the tooth. 25 Additionally, the guide arm 88 does not only restrict movement of the coupling pin 30 for both mounting and extraction, it also helps to stop fines getting into the locking adaptor aperture once the pin is installed as it rests over the keyway 64 defined by the sidewall 50 of the tooth 36 once in locked position. This feature may not be essential but is beneficial.

17 It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention. 5

Claims (5)

1. A tooth and adaptor assembly for use on earthmoving machinery, the assembly comprising: an adaptor configured to be mounted to a leading edge of a ground engaging 5 component of the earth moving machinery, the adaptor having an adaptor aperture extending from a side surface of the adaptor at least partially into the adaptor; a tooth adapted to be received over a leading part of the adaptor, and to be releasably secured thereto, the tooth having a sidewall defining a first aperture which, when the tooth is received by the adaptor, is aligned with the adaptor aperture 10 thereby to form a locking passage; a coupling pin, shaped and sized to be received in the locking passage, the coupling pin comprising an engaging key; and a retainer insert to be received in a pocket within at least one of the adaptor's side surface and the sidewall of the tooth, the retainer insert having a key receiving 15 formation to interact with the engaging key of the coupling pin in order for the coupling pin, once received in the locking passage, to rotate the retainer insert in the pocket to a locked position, in which locked position the coupling pin is secured in the locking passage with the tooth being secured over the leading part of the adaptor.

2. A tooth and adaptor assembly as claimed in claim 1 wherein the pocket has a 20 locking formation, and the retainer insert has a complementary locking formation to engage with the locking formation of the pocket once in the retainer insert is in the locked position, the combination of the locking formations of the pocket and retainer insert restricting the rotation of the retainer insert in the pocket thereby securing the coupling pin in the locking passage. 25

3. A tooth and adaptor assembly as claimed in claim 1 or claim 2 wherein the pocket is defined by one or both of the adaptor's side surface and the sidewall of the tooth. 19

4. A tooth and adaptor assembly as claimed in any one of claims 1 to 3 wherein the first aperture defined in the sidewall of the tooth further defines a keyway configured to allow the engaging key of the coupling pin to pass through the sidewall 5 and to be received by the key receiving formation of the retainer insert once the retainer insert is received in the pocket and the key receiving formation is aligned with the keyway.

5. A tooth and adaptor assembly as claimed in any one of claims 1 to 4 wherein the pocket limits the movement of the retainer insert in the pocket to rotation and 10 further wherein the pocket limits the lateral movement of the coupling pin.