AU2022404606A1

AU2022404606A1 - Wear assembly for a bucket of an extraction or works machine

Info

Publication number: AU2022404606A1
Application number: AU2022404606A
Authority: AU
Inventors: Fabrice MARCHAND
Original assignee: Safe Metal SAS
Current assignee: Safe Metal SAS
Priority date: 2021-12-06
Filing date: 2022-12-05
Publication date: 2024-06-06
Also published as: FR3129957A1; CA3239033A1; WO2023104736A1; CN118355171A; KR20240115828A; MX2024006875A; FR3129957B1; EP4444956A1

Abstract

Wear assembly, comprising a tooth holder (3) and a tooth (1) for a bucket, and also a sheath (5), with a housing duct (52), the sheath being received in the tool holder. Also provided is a key (7) which is received in the housing duct (52) by pivoting between an insertion orientation, so as to be slid into the housing duct, and a locking orientation, so as to clamp the tooth against the tooth holder by the key bearing against the tooth and the sheath bearing against the tooth holder under the action of the key, in opposite directions. In order to facilitate manufacture without prejudicing reliability, the key is monolithic and comprises both a bearing cam (71), for bearing against the tooth holder, and a bearing end (72), for bearing against the tooth (1).

Description

TITLE: Wear assembly for a bucket of an extraction or works machine

The present invention relates to a wear assembly, for a bucket of an extraction or works machine. The invention relates to the field of extraction and works machine equipment, concerning in particular buckets, skips or other receptacles used both to work, in particular dig, scrape and/or pick up, a material and to move this material. The material is generally a heavy, hard, granular and/or abrasive material. For example, the material is soil, rock, aggregate or rubble. In a known way, a bucket comprises a cutting blade equipped with teeth, which are wear parts designed for their ability to attack and penetrate the material being worked and transported by the bucket. It is envisaged that each tooth can be individually replaced when worn. FR 3 011 013 Al discloses a bucket, with a holder and a tooth, which can be locked to the support by means of a connection device. The connection device comprises an elastically deformable sheath, a metal key, a metal toothed cam, a metal crescent and two seals. The key, toothed cam and crescent are received in the sleeve. When the connection device is received in a housing of the holder and the tooth is mounted on the holder, the key and cam are movable in rotation together in an internal cavity of the sleeve, between a configuration of inserting the key into the cam, and one or more locking configurations, where the key bears radially against the tooth, while the cam presses against the sheath so that the sheath bears against the housing of the holder, to form a mating connection of the tooth and the holder. The internal cavity of the sheath also receives the metal crescent, which acts as a bearing to support the rotation of the cam-key assembly. The seals are arranged on either side of the sheath to ensure a watertight seal. This known connection device is generally satisfactory, being particularly durable and reliable despite intensive use of the bucket. However, this connection device is relatively complex to manufacture, given the need to provide a total of six parts. Some critical parts, such as the key and toothed cam, have to be formed by a demanding forging method, while requiring subsequent machining to obtain the toothing and/or to form the head of the key. One of the aims of the invention is to obtain a new wear assembly for a bucket, which is easier to manufacture, without prejudice to its reliability and the ease of replacing the tooth when it is worn.

The invention has as its object a wear assembly, for a bucket of an extraction or work machine, the wear assembly comprising: a tooth holder, which is intended to be fixed to the bucket and comprising a keyway, traversed by a keyway axis; a tooth, which is configured to be nested onto the tooth holder, along a nesting direction; and a keying device. The keying device comprises a sheath, which comprises a housing duct and an external wall, the sheath being configured to be received in the keyway by means of the outer wall, the sheath thereby being fixed in rotation relative to the tooth holder about the keyway axis by means of the outer wall. The keying device comprises a key, which is configured to be received in the housing duct so as to be pivotable relative to the sheath, between an insertion orientation, in which the key is slidable in the housing duct (52) while the sheath is received in the keyway, and a locked orientation, in which, while the sheath is received in the keyway, the keying device clamps the tooth against the tooth holder in the nesting direction under the action of the key, by bearing of the key against a bearing seat belonging to the tooth, in the nesting direction, and the sheath bearing against the keyway in the opposite direction. According to the invention, the key is monolithic and comprises a bearing cam and a bearing end formed in one piece. According to the invention, the bearing of the key against the bearing seat is achieved by the bearing end bearing directly against the bearing seat, in the nesting direction. According to the invention, the bearing of the sheath against the keyway is achieved by the bearing cam bearing against the housing duct, in the opposite direction to the nesting direction. One idea behind the invention is to provide that the bearing cam and the bearing end are constituted of a single part, namely the key, to facilitate the manufacture of the keying device. Indeed, this key can be manufactured in a single operation, to form both the bearing cam and the bearing end in a single piece, for example by forging within the same mold. In the case of a forging or similar manufacturing method to obtain the key, it is not necessary to provide several separate molds to form the bearing cam and the bearing end. Nor is it necessary to provide a notch or other means of coupling between the key and the bearing cam, so that the key drives the bearing cam in rotation, since they are entirely integral by being formed by the same piece. Once the key has been formed, for example by forging, there is therefore advantageously no need to provide additional significant manufacturing steps such as machining, apart from possible deburring. These advantages for the manufacture of the wear assembly do not affect the reliability of the wear assembly, since, when the keying device is received in the keyway with the key in the locking orientation, the tooth is securely clamped and held on the tooth holder. As the tooth wears, the sheath elastically takes up any play to keep the tooth clamped. Tooth assembly remains easy, since the tooth is clamped simply by pivoting the key, thus avoiding the need for striking tools. Preferably, the sheath is monolithic, the external wall and the housing duct being formed in a single piece. Preferably, the bearing cam is brought into contact with the housing duct without any intermediate piece between the key and the sheath. Preferably, the housing duct is coated with a lubricant. Preferably, the bearing seat comprises two primary faces, each primary face being obliquely oriented, by being turned toward the other primary face and in the opposite direction to the nesting direction. Preferably, the bearing end comprises two secondary faces, the bearing end bearing against the bearing seat in that the bearing end is received between the primary faces, with each secondary face bearing against one of the primary faces. Preferably, the tooth comprises a retaining rib. Preferably, the key comprises two radial shoulders, which are formed in one piece with the bearing end and which, when the key is received in the housing duct and the sheath is received in the keyway : capturing the retaining rib between them, parallel to the keyway axis, when the key is in the locking orientation, to immobilize the key relative to the tooth parallel to the keyway axis; and are disengaged from the retaining rib when the key is in the insertion orientation. Preferably, both the key and the tooth comprise rotational stops, which come into rotational stop when the key is in the insertion orientation, to limit pivoting of the key to the insertion orientation and which come into rotational stop when the key is in the locking orientation to limit pivoting of the key to the locking orientation. Preferably, the key comprises a dismantling groove, which is arranged along the bearing end. Preferably, when the sheath is received in the keyway and the key is received in the housing duct, the dismantling groove is: disengaged from the bearing seat, when the key is in the insertion orientation, so that the key can be extracted from the housing duct by introducing a dismantling tool into the dismantling groove; and turned against the bearing seat, when the key is in the locking orientation. Preferably, the key defines a parting line which traverses the bearing cam and the bearing end, the bearing cam and the bearing end being tapered on either side of the parting line. Preferably, the key comprises an actuator head, configured to be coupled with an actuator tool, for actuating the key pivotally between the insertion orientation and the locking orientation, the actuator head being formed in one piece with the bearing cam and bearing end and protruding out of the sheath when the key is received in the housing duct. Preferably, the actuator head is tapered on either side of the parting line. Preferably, to be coupled with the actuator tool, the actuator head comprises an actuator notch and two fingers, which are arranged on either side of the actuator notch to delimit the actuator notch, the actuator notch and the two fingers being traversed by the parting line and being tapered on either side of the parting line. Preferably, the tooth comprises a keyhole, into which the keyway opens when the tooth is received on the tooth holder, the bearing seat being formed on an edge of the keyhole. Preferably, the wear assembly further comprises a plug, which is configured to close the keyhole by capping the keying device while the sheath is received in the keyway and the key is received in the housing duct in the locking orientation. The invention will be better understood on reading the following description, given only as a non-limiting example and made with reference to the annexed drawings presented below.

[FIG. 1] Figure 1 is an exploded perspective view of a wear assembly and actuator socket, according to one embodiment of the invention, where a key is in an insertion orientation and a tooth holder is shown mounted on a bucket.

[FIG. 2] Figure 2 is an assembled perspective view of the wear assembly of Figure 1, from another angle, where the key is in the locked orientation and is masked by a plug.

[FIG. 3] Figure 3 is a partial section of Figure 2 along the sectional planeII.

[FIG. 4] Figure 4 is a side view of the wear assembly of the previous figures, where the key is in the insertion orientation, with the plug omitted.

[FIG. 5] Figure 5 is a side view of the wear assembly of the previous figures, where the key is in the locking orientation, with the plug omitted.

[FIG. 6] Figure 6 is a front view of the key shown in the preceding figures.

[FIG. 7] Figure 7 is a side view of the key shown in the preceding figures.

[FIG. 8] Figure 8 is a front view of a sheath belonging to the wear assembly of the preceding figures, receiving the key in the insertion orientation, the key being in cross section.

[FIG. 9] Figure 9 is a perspective view of the sheath of Figure 8, shown alone.

[FIG. 10] Figure 10 is a perspective view of the plug of Figure 2. Figures 1 to 10 show a wear assembly according to one embodiment of the invention, comprising a tooth 1, a tooth holder 3, a sheath 5 and a key 7. Together, the sheath and key 7 constitute a keying device. The wear assembly preferably comprises a plug 9, visible in Figures 2, 3 and 10. Figure 1 also shows an actuator tool 11, schematically, a dismantling tool 14 and, shown partially dotted, a bucket 13. The bucket 13 belongs to a construction or mining machine. By "works machine" is meant, for example, a backhoe loader, an excavator, a bulldozer or any similar construction machine. By "extraction machine" is meant, for example, a loader, a load-haul-dump (LHD), or any other machine of the same type. The term "bucket" applies to the buckets, skips and other receptacles fitted to such machines, capable of scraping, picking up and/or moving materials, preferably from the ground, with a view to evacuating them from a given location to others. The bucket 13 forms a trough with an access opening that is, for example, rectangular in shape. The access opening is delimited by four edges, of which an edge 131 visible in Figure 1, to which the wear assembly is intended to be attached. From among these edges can be counted a leading edge, here formed by the edge 131. Preferably, this edge 131 is located at the lower or upper portion of the bucket 13 and is oriented parallel to the ground. As shown in Figure 1, the tooth holder 3 is intended to be permanently fixed to the edge 131 of the bucket 13 and to receive the tooth 1 to carry it in a removable manner, in order that the tooth 1 can be replaced when it is worn. A nesting direction D31 is defined, which is fixed relative to the tooth holder 3. When the tooth holder 3 is attached to the bucket 13, the direction D31 is directed toward the inside of the bucket 13, by being perpendicular to the edge to which the tooth holder 3 is attached. When the tooth 1 is received on the tooth holder 3, the direction D31 is directed from the tooth 1 toward the tooth holder 3. The tooth holder 3 comprises a base 31, by means of which the tooth holder 3 is attached to the bucket 13, in particular to the edge 131. For this purpose, the base 31 presents, for example, a clamp-like shape which straddles the edge 131, as shown in Figure 1. To secure the tooth holder 3 permanently, the base 31 is preferably welded to the edge 131. The tooth holder 3 comprises a nesting nose 32, to receive the tooth 1 by nesting the tooth onto the nose 32, along the direction D31. Figure 2 shows the tooth 1 nested onto the tooth holder 3. As seen in Figures 1 and 3, the nose 32 and the base 31 are arranged successively along the direction D31. The nose 32 and the base 31 are integral. The nose 32 is directed in the opposite direction to the direction D31. When the tooth holder 3 is attached to the bucket 13, the nose 32 protrudes from the edge 131. The tooth holder 3 comprises a keyway 33, which traverses the tooth holder 3 from one side to the other. The keyway 33 traverses the nose 32. The keyway 33 extends along a keyway axis X33, fixed relative to the tooth holder 3, and which is perpendicular to the direction D31, or at least transverse to the direction D31. Preferably, the keyway 33 is coaxial with the axis X33. Preferably, the keyway 33, and in particular, the axis X33, are parallel to the edge 131 when the tooth holder 3 is attached to the bucket 13. The keyway 33 presents a through end 34 on one side of the tooth holder 3 and a through end 35 on the other side of the tooth holder 3, as shown in Figure 3. Preferably, the tooth holder 3 is monolithic, in that the base 31, the nose 32 and the keyway 33 are formed in one piece. Preferably, the tooth holder is made of steel, either as cast or forged, or cast and then machined, or forged and then machined. The tooth 1 comprises a tip 15, by means of which the tooth 1 is intended to work the material worked by the bucket 13, when the tooth is received on the bucket 13 by means of the tooth holder 3. The tip 15 is used to scrape, pick the material and/or impact the material being worked. Here, the tip 15 forms a slightly flattened point, but could present another shape as a function of the characteristics of the material to be worked and the work to be carried out, in particular a more pointed or flattened shape, or a double-point shape. In the present example, in order to be nested onto the tooth holder 3 in the direction D31, the tooth 1 comprises a cavity 16, a lug 17 and, preferably, a lug 18, which are complementary to the nose 32. Preferably, it is provided that the cavity 16 opens along the direction D31. The cavity 16 extends partly inside the tip 15, opposite the direction D31. When the tooth 1 is nested onto the tooth holder 3, a male portion 36 belonging to the nose 32 is received within the cavity 16, the cavity 16 and the male portion 36 being complementary. Preferably, the male portion 36 and the cavity 16 have a generally pyramidal or frustoconical shape for their contact zone, this shape being divergent along the direction D31. The result is therefore a pyramidal or conical nesting of the tooth 1 onto the tooth holder 3. This particular type of nesting means that clamping the tooth 1 against the tooth holder 3 in the direction D31 secures the tooth on the tooth holder 3 firmly and without play, by ensuring precise centering of the tooth 1. It is provided that, preferably, the lugs 17 and 18 are directed along the direction D31 from the tip 15. The lugs 17 and 18 protrude along the direction D31 from an edge of the cavity 16. Preferably, the lugs 17 and 18 are distributed laterally, opposite each other, so as to extend on either side of the nose 32 when the tooth 1 is nested onto the tooth holder 3. The lug 17 then covers the end 34 of the keyway 33 and the lug 18 covers the end 35. The lugs 17 and 18 traverse the axis X33 when the tooth 1 is nested.

Preferably, the lug 17 comprises a keyhole 19, which passes right through the lug 17 from one side to the other. When the tooth 1 is nested, the keyhole 19 is traversed by the axis X33, falling in line with the end 34 of the keyway 33. Preferably, the lug 18 comprises a keyhole 20, which traverses the lug 18 from one side to the other. When the tooth 1 is nested, the keyhole 20 is traversed by the axis X33, falling in line with the end 35 of the keyway 33. It is provided, for example, that the nose 32 comprises a slot 37, recessed, to accommodate the lug 17 when the tooth 1 is nested. The slot 37 is positioned in the direction D31 relative to the male portion 36, at the boundary between the nose 32 and the base 31. An edge of the slot 37, delimiting the slot 37, extends about the end 34. When the tooth 1 is nested, the edge of the slot 37 extends about the lug 17. It is provided, for example, that the nose 32 comprises a slot 38, recessed, to accommodate the lug 18 when the tooth 1 is nested. The slot 38 is positioned in the direction D31 relative to the male portion 36, at the boundary between the nose 32 and the base 31. An edge of the slot 38, delimiting the slot 38, extends about the end 35. The slots 37 and 38 are arranged on either side of the tooth holder 3, being traversed by the axis X33. When the tooth 1 is nested, the edge of the slot 37 extends about the lug 17. As can be seen in Figures 1 and 3, the tooth 1 comprises a bearing seat 21, which here, is formed in the keyhole 19. The bearing seat 21 occupies, for example, only a portion of the circumference of the keyhole 19 about the axis X33, namely the portion in the direction D31. Generally speaking, when the tooth 1 is nested, the seat 21 is turned in the opposite direction to the direction X33. The seat 21 forms two faces 22, known as "primary faces". Preferably, the faces 22 are oblique relative to each other, in other words, they are oriented in a "V". The faces 22 are facing each other, in such a way as to create a receiving space between them. Preferably, when the tooth 1 is nested, the faces 22 are at the same height along the axis X33, being turned toward the axis X33. Advantageously, the faces 22 are then parallel to the axis X33. When the tooth 1 is nested, the faces 22 are oriented in such a way as to converge along the direction D31. The faces 22 are turned in the opposite direction to the direction D31. Preferably, when the tooth 1 is nested, the faces 22 are symmetrical relative to a plane parallel to the direction D31 and the axis X33. Preferably, the faces 22 are substantially flat. For example, the faces 22 are inclined relative to each other at an angle of 60 degrees, each face 22 being oriented at an angle of 30 degrees relative to the direction D31. Preferably, the tooth 1 is monolithic, in that the tip 15, the cavity 16, the lugs 17 and 18 and the keyholes 19 and 20 are formed in one piece. Preferably, the tooth is made of steel, either as cast or forged, or cast and then machined, or even forged and then machined. By complementarity of the nose 32 with the cavity 16 and the lugs 17 and 18, nested the tooth 1 onto the tooth holder 3 fully immobilizes the tooth 1 on the tooth holder 3, except that the tooth 1 is not held back for its translation relative to the tooth holder 3 in the opposite direction to the direction D31. Complete immobilization of the tooth 1 is achieved by the keying device, comprising the sheath 5 and the key 7, as explained below. The sheath 5 can be seen in Figures 1, 3, 8 and 9. The sheath 5 is configured to be received in the keyway 33, as shown in Figure 3, and to receive the key 7 therein. Thus, the keying device is received in the keyway 33 by means of the sheath 5. The sheath 5 comprises an outer wall 51, a housing duct 52, an end 53 and an end 54. Preferably, the sheath 5 is monolithic, in that outer wall 51, the housing duct 52 and the ends 53 and 54 are formed in one piece. It is provided that the sheath 5 is elastically deformable, unlike the key 7, the tooth 1 and the tooth holder 3, which are provided to be rigid. To this end, the sheath 5 is made of elastomer, for example, and formed by molding. Preferably, when the sheath 5 is received in the keyway 33, the sheath 5 does not project beyond the ends 34 and 35, as shown in Figure 3. In particular, the end 53 is flush with the end 34 and the end 54 is flush with the end 35. The housing duct 52 is preferably a through passage opening at the end 53 and at the end 54. Alternatively, the housing duct 52 opens at least at the end 53. When the sheath 5 is received in the keyway 33, the axis X33 traverses the duct 52 from the end 53 to the end 54. Preferably, when the sheath 5 is not deformed, the duct 52 is coaxial with the axis X33. The outerwall 51 is turned outward, surrounding the housing duct 52, which is turned inward. The wall 51 connects the ends 53 and 54. The outer wall 51 surrounds the housing duct from the end 53 to the end 54, and surrounds the axis X33 when the sheath 5 is received in the keyway 33. The sheath 5 is received in the keyway 33 by means of the outer wall 51. Preferably, when the sheath 5 is received in the keyway 33, the outer wall 51 is in direct contact with the keyway 33, preferably over all or most of the surface of the outer wall 51. To this end, the keyway 33 and the wall 51 are complementary in shape. The outer wall 51 and the keyway 33 are shaped to prevent rotation of the sheath 5 about the axis X33, when the sheath 5 is received in the keyway 33.

Optionally, recesses are provided on the outer wall 51 to encourage deformation of the sheath 5. In this case, the outer wall 51 is advantageously in contact over its entire surface against the keyway 33, except for these recesses. To this end, for example, the outer wall 51 locally forms a radial groove 55 in relief, here starting from the end 53 over a portion of the length of the sheath 5, this groove 55 being received in a radial groove 39 in recess, formed over part of the length of the keyway 33 starting from the end 34. Alternatively or in addition, for example, the outer wall 51 forms a flat 56, extending from the end 53 to the end 54, visible in Figures 1 and 9, and shown by transparency in dotted lines in Figure 8. This flat 56 is complementary to a flat formed by the keyway 33, from the end 34 to the end 35. Alternatively, or moreover, it could be provided that the outer wall 51 and the keyway 33 present a transverse egg-shaped section along the axis X33, to block rotation. With the exception of their parts blocking rotation of the sheath 5 about the axis X33 relative to the tooth holder 3, the outer wall 51 and the keyway 33 advantageously have a complementary frustoconical shape, converging along the axis X33 from the end 34 toward the end 35, and from the end 53 toward the end 54. The sheath 5 is compliant so that it can be inserted into the keyway 33 and removed from the keyway 33 along the axis X33, by means of the end 34, preferably in the absence of the tooth 1. Advantageously, it is provided that the complementarity of the frustoconical shape of the outer wall 51 and the keyway 33 means that the sheath 5 must be inserted into the keyway 33 until it abuts the frustoconical stop of the keyway 33 along the axis X33, thus avoiding the need to position the sheath 5 beyond the end 35 of the keyway 33. The housing duct 52 is designed to receive the key 7, in such a way that the key 7 can be pivoted relative to the sheath 5, between a so-called "insertion orientation", shown in Figures 1, 4 and 8, and a separate so-called "locking orientation", shown in Figures 3 and 5. Figure 2 shows the wear assembly, while the key 7 is in the locking orientation, although the key 7 is not visible in Figure 2 by being masked by the plug 9. In the present example, when the sheath 5 is received in the keyway 33 and the tooth 1 is received on the tooth holder 3, the end 53 of the duct 52 opens out in front of the keyhole 19 of the tooth 1. Preferably, the end 54 of the duct 52 opens out in front of the keyhole 20 of the tooth 1. The duct 52 presents a shape that allows rotation of the key 7 about an axis parallel or slightly inclined relative to the axis X33. It is provided that, in transverse section relative to the axis X33, the duct 52 is circular in shape for most of its circumference. Preferably, as shown in Figure 8, a portion 57 of the circumference of the circular section of the duct 52 is egg-shaped, in other words, depressed, with a radius locally increased relative to the radius of the circular shape of the rest of the circumference. Thanks to this arrangement, pivoting of the key 7 in the duct 52 is facilitated, as the egg-shaped portion 57 allows to reduce the friction, by being radially spaced from the key 7. In other words, thanks to the egg-shaped portion 57, the key 7 is in contact with the duct 52 over only a portion of its circumference. Preferably, the duct 52 is frustoconical, converging, along the axis X33 from the end 53 to the end 54, as visible in Figure 3. In general, the sheath 5 is advantageously tapered from the end 53, so that it can be obtained in a single molding operation, in a single mold, without any subsequent reshaping or assembly of the sheath 5. This tapered shape is reflected, for example, in the aforementioned conicity of the outer wall 51 and the duct 52. The mold cavities are displaced relative to one another along an opening axis of the mold traversing the duct 52, parallel to the axis X33. This allows the sheath obtained to be monolithic, being formed from the same elastically deformable material, such as an elastomer. To facilitate pivoting of the key 7 in the housing duct 52, preferably, it is provided to coat the housing duct 52 with a lubricant, by carrying out, for example, greasing for life. This is particularly useful when the duct 52 is formed in one piece with the outer wall 51, with the elastically deformable material. Then, pivoting the key 7 is achieved without any intermediate piece between the key 7 and the sheath 5. However, lubricant-free pivoting can also be provided. Alternatively, the sheath 5 can be provided to be non-monolithic, in that a portion or all of the duct 52 is formed by a rigid piece, for example, metal, while the remainder of the sheath 5, including the outer wall 51, is formed with elastically deformable material, for example, elastomer. The rigid piece then acts as a bearing for the pivoting of the key 7. In this case, advantageously, it can be provided that the elastomer is overmolded onto the rigid piece forming the duct 52, the rigid piece being bonded to the elastomer. Alternatively, it can be provided that the sheath 5 is of elastomer, within which a metal or fiber reinforcement is embedded, to structurally reinforce the sheath 5 and improve its durability. The key 7 defines an axis X71 and an axis X72 which are not coincident, preferably parallel or slightly inclined relative to each other. In the present example, the key 7 comprises, in this order along the axis X71, a distal end 73, a bearing cam 71, a bearing end 72 and an actuator head 74. The bearing cam 71 is coaxial with the axis X71, while the distal end 73 and the head 74 are coaxial with an axis X72, parallel to and not coincident with the axis X71. In other words, the cam 71 is offset relative to the bearing end 72 and, preferably, relative to the distal end 73 and the head 74. The ends 72 and 73 are separated by the cam 71. The cam 71 and the head 74 are separated by the end 72. The key 7 is entirely monolithic, in that all parts of the key 7 are formed in one piece. In particular, the bearing cam 71 is made in one piece with the bearing end 72, and preferably with the end 73, the head 74, and all the parts of the key 7 described here. Preferably, it is provided to make the key 7 entirely of steel, as-forged, without further machining. Preferably, the key 7 is entirely formed by a single forging operation, with metal introduced in the form of a billet, into a single mold. Preferably, no assembly operation and no machining or other subsequent reworking is carried out, except possibly for a burrformed at the parting line P7 as a result of forging. At the very least, the need to rework the key 7 after forging is reduced. This makes it easier to manufacture the key 7. Alternatively, the key 7 can be obtained by molding rather than forging. In order to obtain the key according to such a manufacturing method, it is provided, as can be seen in particular in Figure 6, that the key 7 defines a parting line P7, which traverses the bearing cam 71, the bearing end 72, and preferably the actuator head 74 and the distal end 73, which are tapered on either side of the parting line P7. In Figure 3, the section is taken according to the parting line P7, which is then coincident with plane 1l. The axes X71 and X72 are included within the parting line P7. On either side of this parting line P7, it is provided that all parts of the key 7 are tapered, in particular the cam 71, the end 72, the end 73 and the head 74. In other words, no face of the key 7 is undercut with respect to the parting line P7. In other words, all external surfaces and contours of the key 7 are oriented, relative to the parting line P7, so as to be able to be removed from a mold that opens along a direction perpendicular to the parting line P7. More precisely, the key 7 is designed to be able to be formed in a mold that comprises a first cavity, to form the entire portion of key 7 on one side of the parting line P7, and a second cavity, to form the entire portion of key 7 on the other side of the parting line P7, the two cavities being joined at the parting line P7 during forging. The key 7 is designed to be received in the sheath 5, in particular in the duct 52, as particularly visible in Figure 3. The key 7 is received in the duct 52 in that the bearing cam 71 is received inside the duct 52 and in that, if the tooth 1 is nested, the end 72 and the head 74 are received in the keyhole 19 and the end 73 is received in the keyhole 20. Preferably, once the key 7 is received, the key 7 does not protrude beyond the tooth 1 along the axis X33, in particular, the end 72 and the head 74 are fully received in the keyhole 19 and the keyway 33, and the end 73 is fully received in the keyhole 20 and the keyway 33.

The cam 71 is fully received in the keyway33 without protruding beyond it along the axis X33. Once received in the duct 52, the key 7 can be pivoted between the insertion orientation and the locking orientation relative to the sheath 5, by means of the head 74. In order to carry out this pivoting, it is provided that the key 7 will make less than one complete revolution about the axis X33 relative to the sheath 5 and the tooth holder 3. For example, the key 7 makes a half-turn. In the example, when the key 7 is in the insertion orientation, the axis X71 is in the direction D31 relative to the axis X72, and when the key is in the locking orientation, the axis X72 is in the direction D31 relative to the axis X71. In the insertion orientation, the cam 71 protrudes in the direction D31 relative to the end 73, and the end 72 protrudes in the opposite direction from the direction D31 relative to the cam 71. In the locking orientation, the cam 71 protrudes in the direction opposite to the direction D31 relative to the end 73, and the end 72 protrudes in the direction D31 relative to the cam 71. In both orientations, it is advantageously provided that the parting line P7 is parallel to the direction D31. In order to be coaxial with the axis X72, it is provided that the end 73 is generally cylindrical with a circular base, centered on the axis X72, at least over part of its length along the axis X72. In order to be formed as a single piece with the rest of the key 7, it is advantageously provided that the end 73 is tapered on either side of the parting line P7, being traversed by the parting line P7. In order to be coaxial with the axis X71, it is provided that the cam 71 presents a form of revolution centered on the axis X71, for the majority of its circumference about the axis X71. The cam 71 presents a bearing portion 81 and a dorsal portion 82, both of which are traversed by the parting line P7 and extending along the entire length of the cam 71, for connecting the end 72 to the end 73. The portion 81 protrudes radially from the end 73, parallel to the parting line P7, while the portion 82 is in extension of the end 73. In the insertion orientation, the portion 81 is directed in the direction D31, while the portion 82 is directed in the opposite direction. In the locking orientation, the portion 81 is directed in the opposite direction to the direction D31, while the portion D82 is directed according to the direction D31. In order to be formed as a single piece with the rest of the key 7, it is provided that the cam 71 is tapered on either side of the parting line P7, by being traversed by the parting line P7, including the portions 81 and 82. The end 72 comprises a bearing portion, forming two faces 83, and a dorsal portion 84. The dorsal portion 84 and the bearing portion forming the faces 83 are both traversed by the parting line P7.

The faces 83, known as "secondary faces", are visible in Figure 6, one of the faces 83 is visible in Figure 1, while the other face being visible in Figure 7. The faces 83 are complementary to the faces 22 of the seat 21 formed by the tooth 1, as explained below. Preferably, the faces 83 are symmetrical relative to the parting line P7. Preferably, the faces 83 are substantially flat. Preferably, the faces 83 are arranged at the same height along the axis X72. Preferably, the faces 83 are "V"-oriented, in other words, they are oriented in such a way as to converge from the axis X72, on either side of the parting line P7, being turned away from each other. For example, the faces 83 are inclined relative to each other at an angle of 60 degrees, each face 83 being oriented at an angle of 30 degrees relative to the parting line P7. Preferably, the bearing portion of the end 72, forming the faces 83, is turned away from the bearing portion 81, about the axis X71 and/or the axis X72. The end bearing portion 72, forming the faces 83, is turned to the same side as the dorsal portion 82. The dorsal portion 84 is preferably hemi-cylindrical, extending the bearing portion 81 of the cam 71. In order to be integral with the rest of the key 7, it is provided that the end 72 is tapered on either side of the parting line P7, being traversed by the parting line P7, including the bearing portion forming the faces 83 and the dorsal portion 84. In the insertion orientation, the bearing portion forming the faces 83 is directed in the opposite direction from the direction D31, while the portion 84 follows the direction D31. In the locking orientation, the bearing portion forming the faces 83 is directed along the direction D31, while the portion 84 is in the opposite direction. In the insertion orientation, the key 7 can be slid relative to the sheath 5 along the axis X33 to be withdrawn or inserted into the sheath 5, while the sheath is received in the keyway 33, whether or not the tooth 1 is nested onto the tooth holder 3. The insertion or withdrawal of the key 7 is carried out through the keyhole 19 of the tooth 1. In order to be inserted in this way, it is provided that the key 7, when it is in the insertion orientation, slides through the keyhole 19, the duct 52 and the keyhole 20, without deforming the sheath 5 and without coming into contact with the tooth 1, or without bearing against the tooth 1. It is advantageously provided that the end 73 is radially thinner than the cam 71 to pass through the duct 52 without difficulty, while the cam 71 is radially thicker, to be directly in contact with the duct 52, substantially on all the perimeter of the duct 52, except on the possible egg-shaped portion 57 which is recessed relative to the cam 71, as shown in Figure 8 where the key 7 is cut at the level of the cam 71. As shown in Figure 8, in the insertion orientation, the bearing portion 81 of the bearing cam 71 is directed along the direction D31 and the dorsal portion 82 is turned in the opposite direction.

The cam 71 being radially thicker than the end 73, the cam 71 forms an axial shoulder 79 close to the end 73, which limits the position of the key 7 relative to the tooth 1, parallel to the axis X33, by coming to bear against the tooth 1, in particular against the lug 18, when the key 7 is inserted into the sheath 5. The axial positioning of key 7 is therefore particularly precise, as shown in Figure 3. In this insertion orientation, the distal end 73 is preferably centered in the keyhole 20. In this insertion orientation, the bearing portion of the bearing end 72, comprising the faces 83, is turned away from the seat 21, in the opposite direction to the direction D31, as shown in Figures 1 and 4. In this insertion orientation, the bearing portion of the bearing end 72 is radially distant from the tooth, in particular, is radially distant from the keyhole 19. In this insertion orientation, the dorsal portion 84 is not in contact, or is in contact without bearing against, the primary faces 22 of the seat 21, being received between the primary faces 22. Preferably, it is provided that, in the insertion orientation, the axes X71 and X33 coincide. Advantageously, it is also provided that the cam 71 is thinner than the end 72 and/or the head 74, so that the cam 71 traverses the keyhole 19 without difficulty. The end 72 and/or the head 74 being radially wider than the cam 71, the risk of inserting the key 7 the wrong way round is reduced. As shown in Figures 3 and 5, pivoting the key 7 into the locking orientation when the tooth 1 is nested causes the keying device to clamp the tooth 1 against the tooth holder 3 in the direction D31. In other words, the key pulls on the tooth 1 in the direction D31 relative to the tooth holder 3, so as to clamp the tooth 1 against the tooth holder 3 in this direction D31. The tooth 1 is then firmly immobilized on the tooth holder 3. In order for the key 7 to achieve this clamping action, it is provided that, in the locked orientation, the end 72 of the key 7 is bearing against the bearing seat 21 of the tooth along the direction D31, and the bearing cam 71 is bearing against the keyway 33, by means of the sheath 5, in the opposite direction to the direction D31. Preferably, it is also provided that the end 73 is bearing against the keyhole 20 of the tooth along the direction D31. It is also provided that there is no other intermediate part between the key 7 and the tooth to provide support. In other words, the end 72 and the end 73 are in direct contact with the tooth 1, in particular with the seat 21 and the keyhole 20 respectively, to exert support in the direction D31. It is provided that the only intermediate part between the key 7 and the tooth holder 3 is the sheath 5 for support. In other words, to exert the support in the opposite direction to D31, the bearing cam 71 is directly in contact with the duct 52 of the sheath 5, and the sheath is directly in contact with the keyway 33 of the tooth holder 3, in the opposite direction to the direction D31. According to the parting line P7, only the sheath is interposed between the cam 71 and the keyway 33. In particular, in the locked orientation, each secondary face 83 of the end 72 comes to bear flat against one of the primary faces 22 of the seat 21 of the tooth 1, the faces 83 being received between the faces 22. The faces 22 being arranged obliquely by being turned toward each other, the end 72 and the tooth 1 are centered relative to each other, perpendicular to the parting line P7, thanks to this bearing. This obliquely opposed bearing of the faces 22 and 83 also results in the global bearing of the end 72 in the direction of the direction D31 against the tooth 1. This bearing of the faces 22 and 83 also produces the locking of the pivoting of the key 7 relative to the tooth holder 3, which prevents, during use of the wear assembly, the key from accidentally returning to the insertion orientation. However, applying sufficient torque to the head 74 of the key 7, allows the key 7 to be pivoted back into the insertion orientation to remove the key 7 and carry out the tooth 1 replacement. Alternatively, instead of the faces 83, it could be provided that the bearing portion of the bearing end 72 is hemi-cylindrical and centered on the axis X72, while the seat presents a complementary shape. In particular, in the locked orientation, the portion 84 is oriented in the opposite direction to the seat 21, by being directed in the opposite direction to the direction D31. As a result, the portion 84 extends radially distant from the keyhole 19. Preferably, in the locked orientation, the end 73 comes to bear against a portion of the keyhole 20, along the direction D31. As this bearing is a cylinder-cylinder bearing, it tends to center the key 7 and the tooth 1 relative to each other perpendicularly to the parting line P7. Advantageously, it is provided that the end 73 completely closes the keyhole 20, to the nearest rotational clearance, in order to prevent the introduction of foreign bodies through the keyhole 20 into the wear assembly during use. In particular, in the locked orientation, as shown in Figure 3, the bearing portion 81 of the cam 71 comes to bear against a portion 59 of the duct 52 in the opposite direction to the direction D31. The portion 59 is preferably adjacent to the portion 57. As shown in Figure 3, the sheath 5 is elastically deformed at the portion 59 by being squeezed between the portion 81 of the cam 71 and the keyway 33. In order to illustrate this deformation, Figure 3 shows a hatched zone representing the offset of the portion 59 in the opposite direction to the direction D31, relative to its initial position referenced 59A. Figure 8 shows the portion 59 while the sheath is not deformed. This deformation of the sheath 5 causes the sheath 5 to push the key 7 in the direction D31, with the key 7 then driving the tooth 1 in the direction D31 to clamp it against the tooth holder, by means of the ends 72 and 73. In other words, the ends 72 and 73 are held against the seat 21 and against the keyhole 20 respectively, under the elastic action of the sheath 5. This elasticity allows to take up any play that may be created parallel to the direction D31 during use of the wear assembly, by wear or caulking of the tooth 1 and/or the tooth holder 3 by caulking and/or abrasion. Even when the wear assembly is worn, the tooth 1 remains clamped. The bearing of the key 7 against the tooth 1 along the direction D31 is advantageously distributed on either side of the tooth 1, on the lugs 17 and 18, respectively, by bearing of the ends 72 and 73 of the key. The bearing of the key 7 against the keyway 33 is carried out in the opposite direction by means of the cam 71, between the ends 72 and 73. During pivoting of the key 7 from the insertion orientation to the locking orientation, the faces 83 rotate past the faces 22, while the key 7 is held against the tooth 1 along the direction D31 by the elasticity of the sheath 5, thus indexing the rotation until the locked orientation is reached. While the technician rotates the key 7, the indexing effect is felt, which indicates that the tooth 1 has been duly clamped. Preferably, as visible in Figures 1 and 3, the tooth 1 comprises a retaining rib 23, to axially retain the key 7 when it is received in the locking orientation, while not opposing insertion and withdrawal of the key when in the insertion orientation. Preferably, the retaining the rib 23 is formed on the edge of the keyhole 19. For example, the rib 23 is formed between the two faces 22 of the seat 21, thus connecting the faces 22 together. The rib 23 is at the same height as the faces 22 along the axis X33. More generally, it is advantageously provided that the rib 23 occupies only a portion of the keyhole 19 so that the key 7 cooperates axially with the rib 23 only in the locking orientation and not in the insertion orientation. In the present example, when the tooth 1 is received on the tooth holder, the rib is directed in the opposite direction to the direction D31, being formed on a portion of the keyhole 19 on the side of the direction D31. Complementary to the rib 23, the key 7 comprises a radial shoulder 85 and a radial shoulder 86, which are distant from each other along the axis X71. The shoulders 85 and 86 are formed at the bearing end 72. More specifically, the shoulder 85 axially connects the cam 71 to the bearing end 72 and the bearing end 72 connects the shoulder 85 to the shoulder 86. In particular, the faces 83 connect the shoulders 85 and 86 to each other. Each radial shoulder 85 and 86 occupies only a portion of the key 7 about the axis X71, so that the rib 23 cooperates with the shoulders 85 and 86 only in the locking orientation and not in the insertion orientation. The two radial shoulders 85 and 86 project radially from the bearing end 72 in the same direction. For example, in the locking orientation, the shoulders 85 and 86 are directed along the direction X31. In the insertion orientation, the shoulders 85 and 86 are directed in the opposite direction. In order to be formed in one piece with the rest of the key, the shoulders 85 and 86 are advantageously tapered on either side of the parting line P7, both being traversed by the parting line P7. In the locking orientation, as shown in Figure 3, the rib 23 is captured between the two shoulders 85 and 86, to immobilize the key 7 along the axis X33 relative to the tooth 1 and the tooth holder 3. More precisely, the shoulder 85 comes to bear against the rib 23 parallel to the axis X33, in the direction of withdrawal of the key 7, to prevent said withdrawal. The shoulder 86 comes to bear against the rib 23 parallel to the axis X33, in the direction of insertion of the key 7, to ensure that the key 7 is not inserted too far into the sheath 5. In the insertion orientation, the shoulders 85 and 86 are disengaged from the rib 23, being turned away from the rib 23, to allow sliding of the key 7 parallel to the axis X33 relative to the sheath 5. In other words, the shoulders 85 and 86 are not bearing axially against the rib 23 when sliding the key 7 and therefore do not oppose this sliding. Preferably, as can be seen in Figures 4 to 7, the key 7 comprises a stop spline 87A, which is, for example, formed radially in relief at the bearing end 72. The spline 87A is preferably formed on a portion of the key 7, which is radial to the axis X72, the spline 87A projecting perpendicularly relative to the parting line P7, about the axis X72. In other words, the spline 87A is positioned at a quarter-turn of the key 7 relative to the portion bearing the faces 83. For example, in the insertion orientation, the spline 87A is directed perpendicularly relative to the direction D31, toward the underside of the tooth 1 as shown in Figure 4, in other words, toward the outside of the bucket 13, whereas in the locking orientation, the spline 87A is directed in the opposite direction, as shown in Figure 5, in other words, toward the top of the tooth 1 and toward the inside of the bucket 13. Preferably, in order to be formed in one piece with the rest of the key 7, the spline 87A is tapered on one side only of the parting line P7. Complementary to the spline 87A, as seen in Figures 1, 4 and 5, the tooth 1 comprises a stop notch 24 and a stop notch 25, here formed on the edge of the keyhole 19. Preferably, the two notches 24 and 25 are arranged diametrically opposite one another in the keyhole 19, relative to the axis X33. Advantageously, the two notches 24 and 25 are turned in the opposite direction to the direction D31.

The spline 87A and the notches 24 and 25 form rotational stops to limit the pivot stroke of the key 7 from the insertion orientation to the locking orientation, when the key 7 is received in the sheath 5, itself received on the tooth holder 3, and the tooth 1 is received on the tooth holder 3. As shown in Figure 4, when the key 7 is turned in the insertion orientation, the spline 87A comes into rotational stop against the notch 24 in a direct direction, to prevent the key 7 from being pivoted beyond the insertion orientation. As shown in Figure 5, when the key 7 is turned in the locking orientation, the spline 87A comes into rotational stop against the notch 25 in an indirect direction, to prevent the key 7 from being pivoted beyond the locking orientation. The pivoting of the key 7 is therefore limited to the insertion and locking orientations, being only allowed to pivot between these two orientations. Preferably, complementary to the spline 87A, as visible in Figures 8 and 9, the sheath 5 comprises a stop notch 58A, formed at the end 53 of the sheath 5. When the key 7 is in the insertion orientation, the spline 87A advantageously comes into rotational stop against the stop notch 58A in the direct direction. Preferably, about the axis X72, the shoulder 85 extends radially as far as the spline 87A, as clearly visible in Figure 6. As visible in Figure 7, the spline 87A protrudes axially from the shoulder 85 in the direction of the shoulder 86. The shoulder 85 therefore advantageously protrudes radially to occupy a sector of at least 90 degrees from the spline 87A, for example 135 degrees as in the present example, about the axis X72. The shoulder 85 therefore forms a collar which bears axially, in the direction of withdrawal of the key 7, against both the rib 23 and the seat 21, to occupy an interstitial space between the sheath 5 and the tooth and reduce the risk of clogging by the introduction of foreign bodies during use of the wear assembly. Preferably, about the axis X72, the shoulder 85 terminates, circularly opposite the spline 87A, by a stop notch 87B. The aforementioned sector is described by the shoulder 85 from the spline 87A to the stop notch 87B, about the axis X72, and here, is 135 degrees. It is provided that the shoulder 85 extends about the axis X72, connecting the spline 87A to the stop notch 87B. Preferably complementary to the notch 87B, as can be seen in Figures 8 and 9, the sheath 5 comprises a stop notch 58B, formed at the end 53 of the sheath 5. When the key 7 is in the locking orientation, the notch 87B advantageously comes into rotational stop against the stop notch 58B in the indirect direction. Preferably, when the key 7 is received in the sheath, the shoulder 85 comes to bear axially against the end 53 of the sheath 5, in the direction of insertion of the key 7. Preferably, this bearing takes place over the entire surface of the face of the shoulder 85, which is turned toward the side of the sheath 5, at least when the key is in the locking orientation. The axial contact of the shoulder 85 with the sheath 5 and/or the bearing of the notch 87B against the notch 58B improves sealing between the key 7 and the sheath 5, preventing the introduction of foreign bodies. Preferably, the key 7 comprises a dismantling groove 88, visible in Figures 1, 3 and 7. The groove 88 is also visible in Figure 6, being shown in dashed lines, while the groove 88 is behind the shoulder 86. The dismantling groove 88 is provided along the bearing end 72. The dismantling groove 88 extends, for example, along a plane orthogonal to the axis X71. In other words, the groove 88 is perpendicular to the parting line P7, being traversed by the parting line P7 and being tapered on either side of the parting line P7. Thus, the groove 88 is formed in one piece with the rest of the key 7, advantageously without any machining of the groove 88. Advantageously, the dismantling groove 88 is provided between the shoulder 86 and the bearing end 72. In other words, the groove 88 is arranged between the two shoulders 85 and 86. The groove 88 is recessed relative to the bearing end 72. For example, the groove 88 connects the faces 83 to each other. The groove 88 is sufficiently narrow to receive the end of the dismantling tool 14, shown schematically in Figure 1, for example the flat end of a flathead screwdriver or crowbar. In a complementary manner, it is advantageously provided that the tooth 1 comprises a dismantling slot 26, as visible in Figures 1 to 5, which is recessed on the edge of the keyhole 19. Here, the dismantling slot 26 is provided radially in the edge of the keyhole 19, in the opposite direction to the direction D31. Axially, the dismantling slot 26 opens out toward the outside of the tooth 1 but is blind toward the inside of the tooth 1. As shown in Figures 1 and 4, when the key 7 is received in the sheath 5 in the insertion orientation, the groove 88 is disengaged from the bearing seat 21, being directed in the opposite direction to the direction D31. On the contrary, the groove 88 opens into the slot 26. The dismantling slot 26 is wide enough to guide the flat end of the dismantling tool 14, introduced from the outside of the tooth 1, into the groove 88, under the shoulder 86, when the key 7 is in the insertion orientation. The dismantling tool 14 can then reach the groove 88 via the slot 26, to slide the key 7 along the axis X33 out of the sheath 5, and thus extract it to dismantle the tooth 1. Preferably, to extract the key 7, it is levered out with the tool 14, by rocking the tool 14 on the tooth 1 at the slot 26. Extraction of the key 7 is therefore particularly easy. As shown in Figures 3 and 5, when the key 7 is received in the sheath 5 in the locking orientation, the groove 88 is turned against the bearing seat 21, in other words, turned in the direction D31 by opening in the direction D31. Therefore, it is provided advantageously that the groove 88 is closed off by the bearing seat 21, being positioned in particular between the faces 22 and against the rib 23. This limits the groove 88 from being blocked by the introduction of foreign bodies during use. The actuator head 74 is configured to be coupled with the actuator tool 11, shown in Figure 1, so that a technician actuates the key 7 pivotally relative to the tooth holder 3, between the locking orientation and the insertion orientation, to lock or unlock the tooth 1. The actuator tool 11 presents here, in the form of a socket, with one end complementary to the head 74 for coupling to it, and a standard end, for example a square socket end, which can be coupled to a ratchet wrench, a bolting machine or an impact screwdriver. The actuator head 74 of the key 7 is formed axially opposite the end 72, so as to open into the keyhole 19 when the key 7 and the sheath are received in the tooth holder 3, as visible in Figures 3 to 5. The head 74 then protrudes from the sheath 5 along the axis X33. As visible in Figures 1 and 3 to 7, in order to be actuated in rotation by the tool 11, the head 74 preferably comprises an actuator notch 89, a finger 90 and a finger 91. The fingers 90 and 91 protrude parallel to the axis X33, in the opposite direction to the cam 71. Preferably, the fingers 90 and 91 are arranged diametrically opposite each other on either side of the axis X72, being distributed along the parting line P7. Each finger 90 and 91 is traversed by the parting line P7, being tapered on either side of the parting line P7 so that it can be formed in one piece with the rest of the key 7. Radially, the fingers 90 and 91 are arranged on either side of the notch 89 to delimit it between them. Axially, the fingers 90 and 91 end at the same height along the axis X72. Radially on the inside, the finger 90 delimits the notch 89. Radially on the outside, the finger 90 advantageously forms the shoulder 86. Radially on the inside, the finger 91, delimits the notch 89, being opposite the finger 90. Radially on the outside, the finger 91 forms part of the dorsal portion 84, having a hemi-cylindrical shape. The notch 89 is centered on the axis X72 and is oriented along a plane perpendicular to the joint parting line P7 and having the axis X72 in common with the parting line P7. The notch 89 opens out parallel to the axis X72, but also radially vis-a-vis the axis X72, in both directions. In particular, in one of the two directions, the notch 89 opens along the spline 87A. In other words, the notch 89 opens out at the periphery of the head 74 in a direction orthogonal to the parting line P7, and also at the periphery of the head 74 in an opposite direction. The notch 89 therefore traverses the key 7 diametrically. Preferably, parallel to the axis X72, the notch 89 extends, recessed, as far as the groove 88, or even as far as the height of the faces 83. Being diametrically through-going and being oriented perpendicular to the parting line P7, the notch 89 is tapered on either side of the parting line P7 so that it can be formed in one piece with the rest of the key during forging, without additional machining. To ensure that notch 89 is thus tapered, it is provided preferably, that each finger 90 and 91, radially on the inside, form two beveled flanks, each flank being arranged on only one side of the parting line P7 while the other flank is arranged on the other side. This is particularly visible in Figure 6, where four beveled flanks can be observed, forming two pairs of flanks diverging on either side of the parting line P7. In addition, the notch 89 being particularly deep, it can still be actuated by the tool 11, even if the head 74 has been severely worn during use of the wear assembly. The head 74 is coaxial with the axis X72, particularly in that the notch 89 is centered on the axis X72 and in that, advantageously, the finger 91 presents an external hemi cylindrical shape centered on the axis X72, forming part of the dorsal portion 84. As shown in Figure 1, to complement the head 74, in particular with the notch 89, while the notch is tapered, it is advantageously provided that the tool 11 presents two fingers 111 and 112, separated by a notch. To couple the tool 11 in rotation with the head 74, the finger 111 is received in the notch 89 on one side of the parting line P7, between the two fingers 90 and 91, and the finger 112 is received in the notch 89 on the other side of the parting line P7, between the two fingers 90 and 91. Preferably, as visible in Figures 1 and 3 to 7, the finger 90 and/or the shoulder 86 are arrow-shaped, oriented radially outward relative to the axis X72, along the parting line P7. As is visible in Figures 4 and 5, the direction of the arrow gives the operator a visual indication of the orientation of the key 7. In the locked orientation, the arrow is directed along the direction D31, to indicate that the key 7 ensures the clamping of the tooth 1 along the direction D31. Preferably, it is provided that the notch 89 presents, on either side of the parting line P7, two parts respectively, the depth of which is different along the axis X72. For example, the part of the notch 89 on the side of the spline 87A is shallower than the part of the notch 89. Thus, in case the key 7 wears during use, at least the deeper part of the notch 89 will enable the technician to pivot the key 7, even if the other part of the notch 89 is worn. In addition, it can be provided that pictograms can be, for example, embossed on the tooth 1 and/or the tooth holder 3, to visually indicate to the technician in which direction to pivot the key 7, and/or whether the key 7 is in the insertion orientation or in the locking orientation. For example, a pictogram 40 formed on the tooth 1 near to the keyhole 19. As is visible in Figures 2, 3 and 9, the plug 9 is designed to close off the keyhole 19, capping the head 74 of the key 7 and covering the end 53 of the sheath 5, while the key 7 is in the locking orientation, being received in the sheath 5, itself received in the keyway 33. To this end, for example, the plug 9 comprises a base 95, the circumference of which corresponds to that of the keyhole 19. The base 95 forms a cover which, when the plug 9 is mounted, extends transversely to the axis X33. Advantageously, the base 95 comprises a tongue 96, which fits into the dismantling slot 26 to close it off, while leaving a small interstitial space to enable the plug 9 to be removed using the tool 14, by lifting the plug 9 via the tongue 96. Parallel to the axis X33, the base 95 preferably comes to bear against the head 74, in particular against the fingers 90 and 91. As shown in Figures 3 and 10, to complement the head 74, in particular the notch 89, while the notch 89 is tapered, the plug 9 comprises two fingers 97, similar in shape to the two fingers 111 and 112, separated by a notch. The two fingers 97 protrude from the base 95, to be received in the notch 89. One of the fingers 97 is received on one side of the parting line P7, between the two fingers 90 and 91, and the other finger 97 is received in the notch 89 on the other side of the parting line P7, between the two fingers 90 and 91. As shown in Figures 3 and 10, the plug 9 advantageously comprises a pin 98, which protrudes from the base 95, perpendicular to the base 95. Preferably, the pin 98 is arranged between the fingers 97 and the tongue 96. Preferably, as visible in Figure 10, the pin 98 is in the form of a portion of a cylinder, which is centered on the axis X72 when the plug 9 caps the key 7. As shown in Figure 3, the pin 98 is complementary to the dorsal portion 84 of the key 7 and comes to bear radially against this dorsal portion 84 when the plug 9 is assembled. The pin 99 then fills a space that is formed radially between the dorsal portion 84 and the keyhole 19, thus preventing clogging by the introduction of foreign bodies during use of the wear assembly. As shown in Figure 10, the plug 9 advantageously comprises a pin 99, which protrudes from the base 95, perpendicular to the base 95. Preferably, the fingers 97 are arranged between the pins 98 and 99. The pin 99 is complementary to the shoulder 86, in the extension of one of the faces 83, and comes to bear radially against this shoulder 86 when the plug 9 is assembled. The pin 99 then fills a space that is formed radially between the shoulder 86 and the keyhole 19, and axially between the seat 21 and the base 95, which prevents clogging by the introduction of foreign bodies during use of the wear assembly.

The pins 98 and 99, the fingers 97 and/or the tongue 96 allow the plug 9 to be held in place on the head 74 by interlocking along the axis X72. In the present case, as shown in Figure 10, it is provided, for example, that the pins 98 and 99 are notched on the part intended to be in contact with the key 7, to ensure this interlocking. In the illustrated example, it has been shown that the sheath 5 and the key 7 are inserted from the right-hand side of the tooth 1 and the tooth holder 3. Alternatively, it could be provided that the sheath 5 and the key 7 are inserted symmetrically in the opposite direction, from the left-hand side. Any feature described above for one embodiment or variant can be implemented for the other embodiments and variants described above, insofar as technically possible.

Claims

1.- A wear assembly for a bucket (13) of an extraction or work machine, the wear assembly comprising: - a tooth holder (3), which is intended to be attached to the bucket (13) and comprising a keyway (33), traversed by a keyway axis (X33); - a tooth (1), which is configured to be nested onto the tooth holder (3) along a nesting direction (D31); and - a keying device, which comprises: 0 a sheath (5), comprising a housing duct (52) and an outer wall (51), the sheath (5) being configured to be received in the keyway (33) by means of the outer wall (51), the sheath (5) thereby being fixed in rotation relative to the tooth holder (3) about the keyway axis (X33) by means of the outer wall (51), and * a key (7), which is configured to be received in the housing duct (52) so as to be pivotable relative to the sheath (5), between: 0 an insertion orientation, wherein the key (7) is able to be slid into the housing duct (52) while the sheath (5) is received in the keyway (33), and 0 a locking orientation, wherein, while the sheath (5) is received in the keyway (33), the keying device clamps the tooth (1) against the tooth holder (3) along the nesting direction (D31) under the action of the key (7), by the key (7) bearing against a bearing seat (21) belonging to the tooth (1), in the nesting direction (D31), and by the sheath (5) bearing against the keyway (33) in an opposite direction; characterized in that: - the key (7) is monolithic and comprises a bearing cam (71) and a bearing end (72) formed in one piece; - bearing of the key (7) against the bearing seat (21) is achieved by bearing of the bearing end (72) directly against the bearing seat (21), along the nesting direction (D31); and - bearing of the sheath (5) against the keyway (33) is achieved by bearing of the bearing cam (71) against the housing duct (52), in the opposite direction to the nesting direction (D31).

2.- The wear assembly according to claim 1, wherein:

- the sheath (5) is monolithic, the outer wall (51) and the housing duct (52) being formed in one piece; - bearing of the bearing cam (71) against the housing duct (52) is achieved without any intermediate part between the key (7) and the sheath (5); and - preferably, the housing duct (52) is coated with a lubricant.

3.- The wear assembly according to any one of the preceding claims, wherein: - the bearing seat (21) comprises two primaryfaces (22), each primaryface (22) being obliquely oriented, being turned toward the other primary face (22) and in the opposite direction to the nesting direction (D31); and - the bearing end (72) comprises two secondary faces (83), the bearing end (72) bearing against the bearing seat (21) in that the bearing end (72) is received between the primary faces (22), with each secondary face (83) bearing against one of the primary faces (22).

4.- The wear assembly according to any one of the preceding claims, wherein: - the tooth (1) comprises a retaining rib (23); and - the key (7) comprises two radial shoulders (85, 86), which are formed in one piece with the bearing end (72) and which, when the key (7) is received in the housing duct (52) and the sheath (5) is received in the keyway (33): • capture the retaining rib (23) between them, parallel to the keyway axis (X33), when the key (7) is in the locking orientation, to immobilize the key (7) relative to the tooth (1) parallel to the keyway axis (X33), and * are disengaged from the retaining rib (23) when the key (7) is in the insertion orientation.

5.- The wear assembly according to any one of the preceding claims, wherein the key (7) and the tooth (1) comprise rotational stops (24, 25, 87A), which come into rotational stop when the key (7) is in the insertion orientation, to limit the pivoting of the key (7) to the insertion orientation and which comes into a rotational stop when the key (7) is in the locking orientation to limit the pivoting of the key (7) to the locking orientation.

6.- The wear assembly according to any one of the preceding claims, wherein: - the key (7) comprises a dismantling groove (88), which is provided along the bearing end (72); and

- when the sheath (5) is received in the keyway (33) and the key is received in the housing duct (52), the dismantling groove (88) is: • disengaged from the bearing seat (21), when the key (7) is in the insertion orientation, so that the key (7) can be extracted from the housing duct (52) by inserting a dismantling tool (14) into the dismantling groove (88), and * turned against the bearing seat (21), when the key (7) is in the locking orientation.

7.- The wear assembly according to any one of the preceding claims, wherein the key (7) defines a parting line plane (P7), which traverses the bearing cam (71) and the bearing end (72), the bearing cam (71) and the bearing end (72) being tapered on either side of the parting line (P7).

8.- The wear assembly according to claim 7, wherein: - the key (7) comprises an actuator head (74), configured to be coupled with an actuator tool (11), to actuate the key (7) by pivoting between the insertion orientation and the locking orientation, the actuator head (74) being formed in one piece with the bearing cam (71) and the bearing end (72) and protruding out of the sheath (5) when the key (7) is received in the housing duct (52); and - the actuator head (74) is tapered on either side of the parting line (P7).

9.- The wear assembly according to claim 8, wherein, to be coupled with the actuator tool (11), the actuator head (74) comprises an actuation notch (89) and two fingers (90, 91), which are arranged on either side of the actuation notch (89) to delimit the actuation notch (89), the actuation notch (89) and the two fingers (90, 91) being traversed by the parting line (P7) and being tapered on either side of the parting line (P7).

10.- The wear assembly according to any one of the preceding claims, wherein: - the tooth (1) comprises a keyhole (19), into which the keyway (33) opens when the tooth (1) is received on the tooth holder (3), the bearing seat (21) being formed on an edge of the keyway (33); and - the wear assembly further comprises a plug (9), which is configured to the keyhole (19) by covering the keying device while the sheath (5) is received in the keyway (33) and the key is received in the housing duct (52) in the locking orientation.