WO2013030334A1

WO2013030334A1 - Mechanical system comprising a device for connection between a wearing part and the support thereof, heavy-construction machine bucket, and method for implementing said system

Info

Publication number: WO2013030334A1
Application number: PCT/EP2012/066959
Authority: WO
Inventors: Fabrice MARCHAND
Original assignee: Afe Metal
Priority date: 2011-09-01
Filing date: 2012-08-31
Publication date: 2013-03-07
Also published as: CN103781974A; FR2979646B1; CA2845667A1; FR2979646A1; BR112014004815A2; AU2012300801A1; EP2751349A1; US20140245645A1; CN103781974B; KR20140079376A

Abstract

The invention relates to a mechanical system (1) comprising a support (10), a wearing part (20) and a device (30) for interconnecting said two components. The support (10) comprises two openings on either side of a housing (14) for receiving the device (30). The device (30) comprises a threaded key (50), a nut (60) that can be screwed to the threaded foot of the key (50), and an elastic sheath (40) provided with a wall that can be adjusted by deformation in the housing (14) of the support (10), by screwing between the threaded foot of the key (50) and the nut (60). Each opening of the housing (14) comprises a first part centred on a central axis (X14) of the housing (14) and radially extending by a maximum of 180° around said central axis, and a second part that is connected to the first part and radially staggered in relation to the central axis. In the insertion configuration, the device (30) passes through the second part of the openings and does not exert any locking force on the wearing part (20). In the locking configuration, the axis (X50) of the key is essentially aligned with the central axis of the housing (14), the wall of the sheath (40) is adjusted in the housing (14) and the device (30) exerts locking forces on the wearing part (20). The invention also relates to a heavy-construction machine bucket (G) comprising such a system, and to a method for implementing such a system (1).

Description

MECHANICAL SYSTEM COMPRISING A DEVICE FOR CONNECTION BETWEEN A WEAR PIECE AND ITS SUPPORT, PUBLIC WORKS AND WORKS MACHINE BUCKET

The present invention relates to a mechanical system comprising a support, a wear part and a connecting device between the wear part and its support, in particular a tooth and its support belonging to a device. construction machinery equipment. The invention also relates to a bucket of construction machinery comprising at least one such system. Finally, the invention relates to a method of implementing such a system.

The field of application of the invention is that of equipment of public works machinery, in particular buckets, buckets or other receptacles capable of scraping, removing and moving materials for the purpose of evacuation from a given place to other operating posts using public works machinery.

In known manner, a bucket comprises a driving blade equipped with wear parts provided for their ability to penetrate the material and protection of the other components of the bucket. On the attacking blades are fixed adapter-holders having a profiled nose, while the wear parts are teeth or shields which are positioned on the support-adapter in a precise connection. This connection is temporary to allow the replacement of wearing parts after wear.

The connection between the wear part and its support can be achieved by a keying. To be effective, the keying devices must provide a rigid connection of the elements they bring together. Conventionally, the assembly and disassembly of the keyings are performed by the action of striking tools, with the risk of injury to operators.

Locking devices are also known which do not require the use of striking tools. In this case, special binding equipment is necessary, especially for dismantling the wear part. On the other hand, the known devices are complex to manufacture and use.

FR-A-2,878,871 discloses a connecting device by keying between a wear part and its support. In the example of Figures 5 to 7, the device comprises two cylinders which are screwed to one another and a rubber sleeve placed between the two. The screwing of the two cylinders deforms the sleeve in a housing of the support, while the cylinders are housed in the openings of the wear part. The connection provided by such a device lacks rigidity, efficiency and reliability. In particular, cylindrical are not systematically in the rear contact position to ensure the retention of the tooth.

US-A-2007 261 278 discloses another connecting device between a wear part and its support. The device comprises a deformable sleeve between two washers, themselves arranged between two cylindrical members. The screwing of the two bodies deforms the sheath in a housing of the support. This connecting device has a similar operation, but a more complex construction, compared with the previous one.

The object of the present invention is to provide an improved connection device, making it possible to dispense with striking operations for mounting and for dismantling wear parts. In particular, the invention is directed to a high-performance, reliable, resistant, simple and practical keying device.

For this purpose, the subject of the invention is a mechanical system, comprising a support, a wear part and a device for connecting the wear part and its support, in particular between a bucket tooth and its support which belong to a public works machine equipment, the support comprising two orifices opening on either side of a receiving housing of the connecting device, the connecting device comprising:

a key having an elongate body along a key axis between a threaded foot and a head,

a nut that can be screwed onto the threaded foot of the key, and

- A sheath of elastically deformable material arranged around the body, provided with a first end pressed against the head, a second end pressed against the nut and an adjustable wall by deformation in the housing of the support, by screwing between the threaded foot of the key and the nut, between an insertion configuration and a locking configuration of the connecting device.

The system is characterized:

- in that each opening opening of the housing comprises a first portion centered on a central axis of the housing and extending radially at most 180 ° about this central axis, and a second portion connected to the first portion and offset radially relative to at the central axis,

in that in the insertion configuration, the connecting device passes through the second portion of the orifices and does not exert any locking force on the wear part, - And in that in the locking configuration, the key axis is substantially aligned with the central axis of the housing, the wall of the sleeve is fitted in the housing and the connecting device exerts locking forces on the piece of 'wear.

Thus, the invention makes it possible to form a rigid connection between the wear part, in particular a bucket tooth, and its support, with great simplicity and high performances. Due to the shape of the openings opening on either side of the housing formed in the support, the device can press the tooth against the support in locking configuration. The key, the nut and the sleeve are removable together in insertion configuration and secured in locking configuration. As a result, the connecting device according to the invention is simple to manufacture and to implement. The assembly and disassembly of the mechanical system is feasible with a consequent time saving and a reduced risk of injury.

According to other advantageous features of the invention, taken separately or in combination:

- The central axis is transverse to a fitting direction of the wear part on the support, preferably perpendicular to the direction of fitting.

- The second part is centered on a secondary axis offset parallel and radially relative to the central axis, the secondary axis preferably being offset relative to the central axis in a direction parallel to and opposite a direction of fitting of the wear part on the support.

- The wearing part comprises two support orifices which are, when the wear part is fitted on the support, each positioned opposite the second part of one of the openings opening from the support housing, and in that in the locking configuration, the connecting device exerts locking forces in the support orifices.

- Each support port comprises a recess in which either the head or the nut is partially housed in locking configuration.

- In the locking configuration, the head and the nut are partially framed, radially to the central axis of the housing, by the first parts of the orifices.

- A flat is provided on the nut, this flat being adapted to be housed, at least in the insertion configuration, in the wear part.

- The key has a center of gravity located on the key axis.

The invention also relates to a bucket of construction machinery, comprising at least one mechanical system as mentioned above. In practice, the bucket generally comprises a series of supports each receiving a tooth, which is comprises as a wear part and is secured to its support by a connecting device.

Alternatively, other equipment of public works can also be equipped with the mechanical system according to the invention.

Finally, the subject of the invention is a method for implementing a mechanical system as mentioned above. The method is characterized in that it comprises the following steps:

a) position the sheath around the body of the key;

b) position the nut on the threaded foot of the key;

c) position the wear part on the support;

d) positioning the connecting device in the housing of the support, in the insertion configuration where the connecting device passes through the second part of the orifices and does not exert a locking force on the wear part;

e) deform the sheath in the housing by screwing the threaded foot of the key in the nut;

f) stopping the screwing, in the locking configuration where the keyway is substantially aligned with the central axis of the housing, the wall of the sleeve is fitted in the housing and the connecting device exerts locking forces on the workpiece wear.

The invention will be better understood on reading the description which follows, given solely by way of nonlimiting example and with reference to the appended drawings in which:

- Figure 1 is an exploded perspective view of a mechanical system according to the invention, comprising a support integral with a partially shown bucket, a wear part, and a connecting device of the part of wear and support, this connecting device comprising a sheath, a threaded key and a nut;

- Figure 2 is an exploded perspective view of the connecting device;

FIG. 3 is an assembled perspective view of the connecting device in an insertion configuration;

FIG. 4 is an assembled perspective view of the connecting device in a locking configuration;

- Figure 5 is a side view along the arrow V in Figure 1, showing the mechanical system and the connecting device in an insertion configuration;

- Figure 6 is a view similar to Figure 5, showing the mechanical system and the connecting device in a locking configuration; - Figures 7 and 8 are views similar respectively to Figures 5 and 6, the wear part not being shown;

- Figures 9 and 10 are elevational views respectively along the arrow IX in Figure 7 and according to the arrow X in Figure 8;

- Figures 1 1 and 12 are sections respectively along the line XI-XI in Figure 9 and along the line XII-XII in Figure 10; and

FIGS. 13 and 14 are sections, respectively along line XIII-XIII in FIG. 7 and along line XIV-XIV in FIG.

In Figures 1 to 14 is shown a mechanical system 1 according to the invention, equipping a bucket G of public works machinery.

The mechanical system 1 comprises an adapter-support 10, a wear part 20 of the tooth type, as well as a device 30 connecting the support 10 and the tooth 20. The system 1 extends substantially along an axis X1, along which one defines a first direction D1 of fitting of the tooth 20 on the support 10 and a second direction D2, parallel and opposite to the first direction D1, disassembly of the tooth 20.

Bucket G is partially shown in Figure 1, for simplification purposes. The support 10 is integral with the bucket G, while the tooth 20 is a wear part to be disassembled when it is too worn by the operation of the bucket G.

The connecting device 30 comprises a sheath 40, and a threaded key or screw 50 and a nut 60 disposed on either side of the sheath 40. The device 30 can be inserted into a housing 14 of the support 10, in a insertion configuration is shown in Figures 3, 5, 7, 9, 1 1 and 13. The relative screwing of the nut 60 and the key 50, in a direction of rotation R1, deforms the sheath 40 interposed between them, from the insertion pattern A to a lock pattern B shown in Figures 4, 6, 8, 10, 12 and 14.

Thus, the device 30 is adjustable between, on the one hand, the insertion configuration A where the sleeve 40 is not in contact or only partially in contact with the housing 14, while the device 30 does not exert retaining force on the tooth 20 and, on the other hand, the locking configuration B where the sleeve 40 is fitted in the housing 14 of the support 10, while the device 30, more precisely the key 50 and the nut 60, press against the tooth 20, then forming a coupling connection between the tooth 20 and its support 10.

To facilitate the identification of the different parts of the mechanical system 1 in the space, a front side 2 is defined at which the tooth 20 is located, a rear side 3 at which the support 10 is located, an upper side 4 oriented to the opposite of the ground when the system 1 is assembled, a first insertion side 30 of the device 30 in the support 10, and a second side 6 opposite the insertion side 5.

The support 10 comprises a base 1 1, partially shown in Figures 1 and 5 to 14, and a fitting nose 12 adapted to be engaged in a cavity of the tooth 20 shaped for this purpose. In addition, a housing 13 for receiving the lugs 23 of the tooth 20 is provided on each side 5 and 6 of the base 1 1. Each housing 13 has walls located towards the rear 3, the top 4 and the bottom, and is open towards the front 2 in order to receive the ears 23. The housing 14 extends through the nose 12 along an axis X14 perpendicular to the axis X1, between the sides 5 and 6. This housing 14 is surrounded by the housing 13 on the sides 5 and 6.

Two orifices 16 are formed on the sides 5 and 6 in the nose 12, opening on either side of the housing 14 along the axis X14. Each orifice 16 comprises a first portion 17 and a second portion 18 connected to each other. Part 17 is a half-cylinder which is centered on an axis X17 coincides with the axis X14, closed on 180 ° towards the rear 3 and opened at 180 ° towards the front 2. Part 18 is a portion of cylinder which is centered on a secondary axis X18 eccentric with respect to axes X14 and X17, closed over more than 180 ° forward 2 and connected to part 17 towards the rear 3. As can be seen in Figure 7, the axis secondary X18 is shifted radially and parallel to the axis X14, in the direction D2 opposite the direction D1 of fitting, along a radial gap e18. The axes X14, X17 and X18 are situated in a median plane Pm10 of the support 10. The orifices 16 generally have an elongated oblong shape along the axis X1. Part 18 defines an opening of transverse dimensions greater than the opening delimited by the portion 17, to facilitate the introduction of the device 30 into the housing 14 through the portion 18 in the insertion configuration A, while the device 30 is housed in the part 17 in the lock configuration B.

As a variant not shown, the orifices 16 may have a different shape adapted to the present application. For example, the portion 17 may be a cylinder portion closed on less than 180 ° in the direction D1, that is, extending radially at most 180 ° about the axis X14. In another example, the portion 17 may be a closed cylinder portion in a slightly inclined direction relative to the axis X1.

The tooth 20 comprises an active portion 21 located forwardly 2 and a hollow portion 22 facing rearward 3. In a manner known per se, the portion 21 is intended to scrape and remove materials, for example earth or gravel, while the portion 22 is provided for the fitting of the tooth 20 on the support 10. More specifically, the portion 22 comprises the inner cavity, not visible in Figures 1, 5 and 6, conformed for the fitting on the nose 12 of the support 10, as well as the lugs 23 which are directed towards the rear 3 and intended to be received in the housings 13, in contact upwards 4 and down, as shown in FIGS. and 6.

Orifices 24, each having a substantially cylindrical shape, are formed in each lug 23, on either side of the tooth 20 on the sides 5 and 6. These orifices 24 are positioned facing the portion 18 of the orifices 16 when the tooth 20 is fitted on the support 10, thus allowing the device 30 to be inserted into the housing 14, then the device 30 being put into operation. Only the ear 23 and the orifice 24 situated on the side 5 are represented in the figures 1, 5 and 6. The ear located on the side 6 is similar to the ear 23 located on the side 5, while the orifice 24 on the side 6 is shaped to receive the nut 60 provided with a flat 64, for example against a shoulder perpendicular to the axis X1. As shown in Figure 1, the orifice 24 located on the side 5 preferably comprises a recess 25, forming a preferred possible support for the key 50. Alternatively, this orifice 24 and / or the recess 25 may have different shapes adapted to this application. For example, the orifices 24 may have oblong shapes more or less elongated. In addition, the orifice 24 located on the side 6 is preferably provided with a recess 25. The orifices 24 are provided to receive the device 30, more precisely the key 50 and the nut 60, resting on the next tooth 20 the direction D1, in the lock configuration B detailed below.

The sheath 40 is of elastically deformable material, for example elastomer. The sheath 40 is elongated between longitudinal ends 41 and 42 along a central axis X40. In the insertion configuration A, the end 41 is located on the side 5, while the end 42 is on the side 6. This distinction is made for the purpose of spatial identification only, it being understood that the ends 41 and 42 are reversible. The sheath 40 comprises a wall 43, which is centered on the axis X40 and curved radially away from this axis X40. The wall 43 defines an outer surface 44 forming an ellipsoid of revolution about the axis X40, truncated at the ends 41 and 42. The wall 43 also defines an interior cavity 45, which is centered on the axis X40, opening at level of the ends 41 and 42 and provided to receive the key 50, with a radial gap formed between the sleeve 40 and the key 50. In practice, the housing 14 and the outer surface 44 have substantially complementary shapes in locking configuration B, so that the wall 43 of the sheath 40 can be adjusted in the housing 14 of the support 10 by marrying its inner contours.

The key 50 is metallic, for example steel. The key 50 comprises a body 53 elongated along an axis X50 between a head 51 and a threaded foot 52. More specifically, the head 51 comprises a hexagonal part 54 actuated by a tool, not shown for the sake of simplification, a first cylindrical portion 55 bearing in the orifice 24 of the tooth 20, a second cylindrical portion 56 having a diameter smaller than the diameter of the portion 55, and an annular shoulder 57 which is formed radially to the axis X50 between the portions 55 and 56 and faces the foot 52. The center of gravity of the key 50 is located on the X50 axis. With the exception of the threading of the foot 52 and the portion 54, the key 50 is a piece of revolution about the axis X50, without eccentric portion.

The nut 60 is made of metal, for example of steel similar to that of the key 50. The nut 60 comprises a first cylindrical portion 61 of support in the orifice 24 of the tooth 20, as well as a second cylindrical portion 62 having a diameter less than the diameter of the portion 61. Parts 61 and 62 are coaxial and centered on an axis X60. The nut 60 also comprises an annular shoulder 63 which is formed radially to the axis X60 between the parts 61 and 62. The flat 64 is formed in the portion 61, with a first flat face parallel and offset radially relative to the X60 axis, and a second flat face perpendicular to the axis X60 and facing away from the portion 62. In other words, the flat 64 is open at the portion 61 but not at the portion 62, forming a stop for the nut 60 disposed in the ear 23 and the orifice 24 located on the side 6 of the tooth 20. A tapping 65 is formed in the nut 60 along the axis X60, opening at the portion 62 , but preferably not opening at the level of the part 61. The tapping 65 is complementary to the threading of the foot 52 of the key 50.

The operation of the connecting device 30 equipping the mechanical system 1 is detailed below.

In a first step a), an operator positions the sheath 40 on the key 50. The body 53 is disposed in the cavity 45 and is surrounded by the wall 43, while the end 41 bears against the head 51.

In a second step b), the operator positions the nut 60 at the end of the key 50, with the shoulder 63 and the shoulder 57 which face each other. The tapping 65 is screwed onto the threaded foot 52, with the sleeve 40 which is interposed between the head 51 and the nut 60. The end 41 is in abutment against the shoulder 57, while the end 42 is in abutment against the shoulder 63. In addition, the wall 43 is fitted radially to the axis X40, on the one hand, on the cylindrical portion 56 at the end 41 and, on the other hand, on the cylindrical portion 62 at the end 42. The connecting device 30 is then assembled, as shown in Figure 3, with the axes X40, X50 and X60 are merged. Subsequently, these axes are designated together under the reference X50. In a third step c), the operator positions the tooth 20 on the support 10, with the active part 21 which is oriented so as to be able to scrape and collect materials in operation of the system 1. The hollow portion 22 is fitted on the nose 12, with complementary planes bearing against each other. The ears 23 are received in the housing 13 of the base 1 1. The orifices 24 are placed vis-à-vis the orifices 16 on the sides 5 and 6, so that the housing 14 is accessible for the introduction of the device 30 in insertion configuration A.

In a fourth step d), the operator positions the preassembled connecting device 30 in the housing 14 of the support 10. The device 30 passes through the orifice 24 and the orifice 16 located on the side 5, starting with the nut 60 and ending with the head 51, with the wall 43 of the sleeve 40 which deforms slightly centripetally in passing. The flat 64 of the nut 60 is housed in the orifice 24 located on the side 6, while the head 51 is positioned in the orifice 24 located on the side 5.

The device 30 is then in insertion configuration A. The device 30, more precisely the key 50 and the nut 60, exert no retaining force on the tooth 20 in the direction D1, so that the relative positions of the support 10 and tooth 20 are not locked. The device 30 passes through the portion 18 of the orifices 16 and the key axis X50 is substantially aligned with the secondary axis X18. In other words, the axis X50 is shifted radially and parallel to the central axis X14 of the housing 14, in the direction D2. A clearance is generally formed between the cylindrical portion 55 and the portion 18 of the orifice 16 located on the side 5. The same portion 55 is not in contact, or is only partially in contact with the inner bore of the orifice 24 located on the side 5. The outer surface 44 of the sleeve 40 is not in contact, or is only partially in contact, with the surface of the housing 14. A length LA of the sleeve 40 is delimited by the axial spacing between the ends 41 and 42 of the sheath 40, in other words between the shoulders 57 and 63 along the axis X50. In addition, a maximum diameter DA of the sleeve 40 is delimited around the axis of key X50 by the surface 44.

At this point, the axes X14, X17, X18 and X50 are located substantially in the median plane Pm10 of the support 10 containing the axis X1, as shown in FIGS. 5, 7, 9, 11 and 13. Nevertheless, except at the level of FIG. of the flat 64, the connecting device 30 is released in the system 1. In other words, the X50 axis is movable in and out of the plane Pm10.

In a fifth step e), the operator deforms the sheath 40 in the housing 14 by screwing the key 50 in the nut 60. More specifically, the operator uses a tool to exert a torque screw around the axis X50 according to the direction of rotation R1, on the portion 54 of the head 51, so that the threaded foot 52 enters the tapping 65. The nut 60 is held in abutment at the flat 64 in the hole 24 located in the side 6. The direction of rotation R1 can be marked by a marking, not shown for simplification purposes, on the head 51 of the key 50, to facilitate the task of the operator.

Thus, the device 30 goes from the insertion configuration A to the locking configuration B. The rotation R1 of the key 50 gradually brings the head 51 closer to the nut 60, so that the sleeve is compressed along the axis X50 between the shoulder 57 and the shoulder 63. The wall 43 is deformed with an accentuation of its bending in the middle part, that is to say an intermediate portion between the shoulders 57 and 63. The outer surface 44 of the sleeve 40 gradually bears against the inner wall of the housing 14, first on the front side 2, then on the sides 5 and 6 and on the rear side 3, as can be seen by comparing FIGS. 1 1 and 12. At the same time, the head 51 and the nut 60 translate in the direction D1, in the orifices 16 and 24 located respectively on the side 5 and the side 6. Thus, the axis X50 shifts in the direction D1, until it is substantially aligned with the central opening X14 of the housing 14. The parts the cylindrical members 55 and 61 are housed in the part 17 of the corresponding orifices 16, until pressing against the orifices 24 and the recesses 25 in the direction D1.

Finally, in a sixth step f), the operator stops the screwing device 30 in the locking configuration B. The key axis X50 is then substantially aligned with the central axis X14 of the housing 14. The device 30 passes through the part 17 of the orifices 16. The wall 43 of the sleeve 40 is fitted in the housing 14 of the support 10, with the surface 44 which follows the contours of the housing 14. A length LB of the sleeve 40, which is less than the length LA, is delimited by the axial spacing between the ends 41 and 42 of the sheath 40 along the axis X50. In addition, a maximum diameter DB of the sheath 40, which is greater than the diameter DA, is delimited around the key axis X50 by the surface 44. The deformation of the wall 43 is no longer possible, so that the sheath 40 has a resistance to crushing and therefore to screwing, which is perceptible by the operator.

In the lock configuration B, the head 51 and the nut 60 exert locking forces on the tooth 20 in the direction D1, while the sleeve 40 presses in the housing 14, forming a coupling connection between the In particular, the locking forces exerted by the device 30 on the tooth 20 in the direction D1 are represented by an arrow F30 in FIG. 6. Advantageously, these forces F30 are distributed symmetrically by report to plan Pm10. The head 51 and the nut 60 are framed upwards 4 and down by the parts 17 of the orifices 16, so as to limit undesirable transverse displacements to the plane Pm10 during operation of the system 1. In addition, the sheath 40 is made of a deformable material rigid enough to prevent or reduce the movements of the device 30 in the direction D2. In addition, a metal insert can be molded in the wall 43 of the sleeve 40. Under these conditions, a tilting of the device 30 in the housing 14 is prevented in the locking configuration B.

Thus, when forces are exerted on the active portion 21, the portion 22 of the tooth 20 is held firmly in the position of use by both the locking device B in the locking configuration B, by the nose 12 and by the walls of houses 13 receiving ears 23.

Subsequently, in a step g) disassembly, the operator can use a tool to unscrew the device 30 in a direction opposite to the direction of rotation R1. The forces exerted by the device 30 on the tooth 20 and the support 10 relax from the locking configuration B to the insertion configuration A. Then, the device 30 can be removed from the system 1, eliminating the connection of coupling between the tooth 20 and the support 10. Thus, the device 30 allows disassembly of the tooth 20 without hammer, after wear thereof, by reverse operations to the mounting.

The constituent elements of the connecting device 30 may be shaped differently without departing from the scope of the invention. In practice, the constituent elements of the device 30 are designed specifically to withstand the wear of the system 1 in operation, as well as to resist multiple assembly and disassembly by a tool.

In variant not shown, the length of the key 50 along the axis X50 is such that neither the actuating portion 54 nor the nut 60 protrude outside the orifices 24 of the lugs 23, when the system 1 is assembled. As can be seen in FIG. 10, the head 51 of the key 50 is then protected in the ear 23 of the tooth 20.

According to another variant not shown, the actuating part or parts of the device 30 with one or more tools are shaped differently. For example, the portion 55 may comprise a circular or polygonal recess, open towards the outside of the side 5, facilitating the penetration of a tool. In another example, the nut 60 may also be shaped for operation by a tool on the side 6. In this case, for example, a cavity or a hexagonal rod may be provided on the portion 61 instead of the flat 64.

According to other variants not shown, the housing 14, the orifices 16 and 24 and the X14 and X18 axes may be shaped or arranged in different ways, as long as the device 30 exerts a sufficient locking force F30 on the tooth 20 in the locking configuration B. For example, the housing 14 may not be cylindrical but have flat bearing faces of the sleeve 40. In another example, the parts 17 and 18 of the orifices 16 may have different shapes of those of Figures 7 and 8, while being interconnected. According to another example, the axis X14 of the housing 14 may not be perpendicular to the axis X1, but inclined in a direction transverse to this axis X1. In a particular example, the X14 and X18 axes can be inclined by 10 ° or 20 ° relative to the axis X1. According to another example, the axes X14 and X18 may be perpendicular to the axis X1 but situated respectively on either side of the plane Pm10. In this case, preferably, the portion 17 of the orifice is situated towards the bottom of the nose 12, while the portion 18 is situated towards the top 4 of the nose 12.

According to another variant not shown, the orifices 24 formed in the lugs 23 may comprise reinforced shoulders and / or heat treatments at the contact zones with the key 50 and the nut 60, in order to have an increased surface hardness and facilitate blocking of the device 30 in the locking configuration B. In addition, the nut 60 and the orifice 24 receiving the nut 60 of the side 6 may be shaped in any manner suitable for the present application, allowing the screwing of the screw 50 in the tapping 65 to move from the insertion configuration A to the locked configuration B.

According to another variant not shown, a metal insert may be arranged between the sheath 40 and the key 50, or may be molded directly into the wall 43.

In addition, the technical features of the various embodiments may be, in whole or in part, combined with each other. Thus, the connecting device can be adapted in terms of cost and performance.

Claims

1. Mechanical system (1), comprising a support (10), a wear part (20) and a device (30) for connecting the wear part (20) and its support (10), in particular between a tooth of bucket (20) and its support (10) belonging to equipment

(G) of public works machine, the support (10) comprising two orifices (16) opening on either side of a housing (14) for receiving the connecting device (30), the connecting device ( 30) comprising:

- a key (50) having a body (53) elongate along a key axis (X50) between a threaded foot (52) and a head (51),

- a nut (60) adapted to be screwed onto the threaded foot (52) of the key (50), and

a sleeve (40) of elastically deformable material arranged around the body (53), provided with a first end (41) pressed against the head (51), a second end (42) pressed against the nut (60); ) and a wall (43) adjustable by deformation in the housing (14) of the support (10), by screwing (R1) between the threaded foot (52) of the key (50) and the nut (60), between an insertion configuration (A) and a locking configuration (B) of the connecting device (30),

the mechanical system (1) being characterized:

in that each orifice (16) opening out from the housing (14) comprises:

a first part (17) centered on a central axis (X14) of the housing (14) and extending radially at most over 180 ° about this central axis (X14), and - a second part (18) connected to the first portion (17) and radially offset from the central axis (X14),

in that in the insertion configuration (A), the connecting device (30) passes through the second portion (18) of the orifices (16) and does not exert any locking force on the wear part ( 20)

and in that in the locking configuration (B), the key axis (X50) is substantially aligned with the central axis (X14) of the housing (14), the wall (43) of the sleeve (40) is fitted in the housing (14) and the connecting device (30) exerts locking forces (F30) on the wear part (20).

2. Mechanical system (1) according to claim 1, characterized in that the central axis (X14) is transverse to a direction (D1) of fitting of the wear part (20) on the support (10), preferably perpendicular to the fitting direction (D1).

3. Mechanical system (1) according to one of the preceding claims, characterized in that the second portion (18) is centered on a secondary axis (X18) offset parallel and radially relative to the central axis (X14), l secondary axis (X18) being preferably offset with respect to the central axis (X14) in a direction (D2) parallel and opposite to a direction (D1) of fitting of the wear part (20) on the support (10).

4. Mechanical system (1) according to one of the preceding claims, characterized in that the wear part (20) comprises two bearing holes (24) which are, when the wear part (20) is fitted on the support (10), each positioned facing the second portion (18) of one of the orifices (16) opening out of the housing (14) of the support (10), and in that in the locking configuration (B) , the connecting device (30) exerts locking forces (F30) in the bearing holes (24).

Mechanical system (1) according to claim 4, characterized in that each bearing orifice (24) has a recess (25) in which either the head (51) or the nut (60) is partially housed in a locking configuration (B).

6. Mechanical system (1) according to one of the preceding claims, characterized in that in the locking configuration (B), the head (51) and the nut (60) are partially framed radially to the central axis (X14) of the housing (14), by the first portions (17) of the orifices (16).

7. Mechanical system (1) according to one of the preceding claims, characterized in that a flat (64) is provided on the nut (60), the flat (64) being adapted to be housed, at least in configuration insertion device (A) in the wear part (20).

8. Mechanical system (1) according to one of the preceding claims, characterized in that the key (50) has a center of gravity located on the key axis (X50).

9. Bucket (G) of public works machine, characterized in that it comprises at least one mechanical system (1) according to one of claims 1 to 8.

10. A method of implementing a mechanical system (1) according to one of claims 1 to 8, characterized in that it comprises the following steps: a) position the sleeve (40) around the body (53) the key (50);

b) position the nut (60) on the threaded foot (52) of the key (50);

c) positioning the wear part (20) on the support (10);

d) positioning the connecting device (30) in the housing (14) of the support (10) in the insertion configuration (A) where the connecting device (30) passes through the second portion (18) of the orifices (16). ) and does not exert a locking force on the wear part (20);

e) deforming the sleeve (40) in the housing (14) by screwing (R1) the threaded foot (52) of the key (50) in the nut (60);

f) stop the screwing (R1), in the locking configuration (B) where the key axis (X50) is substantially aligned with the central axis (X14) of the housing (14), the wall (43) of the sheath (40) is fitted into the housing (14) and the connecting device (30) exerts locking forces (F30) on the wear part (20).