WO2020201587A1

WO2020201587A1 - Locking device for attaching a wear element to a support in an earth-moving machine

Info

Publication number: WO2020201587A1
Application number: PCT/ES2019/070224
Authority: WO
Inventors: José LÓPEZ ALMENDROS; Kamal BOBOUH ABAKOUY; Justo Jesús Ortiz García
Original assignee: Metalogenia Research & Technologies S.L.
Priority date: 2019-04-03
Filing date: 2019-04-03
Publication date: 2020-10-08
Also published as: CA3135312A1; BR112021019851A2; CN113646490B; ZA202106676B; PE20212020A1; MX2021012083A; AU2020255269A1; CA3135312C; ES2944715T3; EP3947832A1; WO2020201418A1; CL2021002451A1; EP3947832B1; CN113646490A

Abstract

A locking device for attaching a wear element (11) to a support (10) in an earth-moving machine, having a housing (9) in the support (10) and an orifice (12) in the wear element in such a way that, in its assembled position, the housing (9) and the orifice (12) are at least partially aligned. The locking device is inserted into the housing (9), and comprises: - a locking element (1), - an internal element (2) - a movement means suited to move the locking element (1) with respect to the internal element (2), in a reversible manner and according to a direction of movement, between a retracted position and an extended position, and - an elastic means which, in the extended position, exerts a force in accordance with the direction of movement, in order to bring the locking element (1) closer to the internal element (2).

Description

LOCKING DEVICE FOR HOLDING A WEAR ELEMENT IN A BRACKET ON AN EARTH MOVING MACHINE

DESCRIPTION

Field of the invention

The invention relates to a locking device for holding a wear element on a support in an earthmoving machine, the support comprising a housing and the wear element comprising a hole so that, in a mounted position, the housing and the hole are at least partially aligned (ie partially overlapping), where the locking device is suitable to be inserted into the housing.

State of the art

Earth-moving machines are used in excavation, demolition, construction, mining, dredging and similar activities. In general, they have a shovel or bucket in which the material is collected. The shovel or bucket is subject to high stresses and great erosion, especially in the area of the lip (also called blade). For this reason, usually the shovel or bucket has a plurality of wear elements that protect it from wear and impacts and / or that improve penetration into the ground, such as teeth, supports or tooth holders (also called adapters) and / or protectors (front and side).

All these wear or protection elements and, in particular, the teeth, are subject to strong mechanical stresses, plastic deformations and heavy wear. For this reason it is usual that they must be replaced with a certain frequency, when the breakage of the same or the wear suffered requires it. In addition, these machines can work in a wide variety of applications, in which It may be necessary to change the tooth design to improve bucket performance.

The wear elements can be attached to other wear elements (such as a tooth attached to an adapter) and / or can be attached to the lip or blade of the bucket or shovel (such as an adapter attached to a lip).

The wear or protection elements can be fixed mechanically (easier and faster to change) or welded (cheaper but difficult to change and with the risk of damaging the blade with welding), depending on the degree of abrasiveness the terrain and the dimensions of the machine. It should also be noted that large earthmoving machines, especially those that operate in quarries and mines, are essential for production at these sites. For this reason, the downtimes of these machines can affect their productivity in a very relevant way and it is very interesting that the change of wear elements can be carried out quickly, safely, and on the spot. , without having to take the machine or the bucket to the workshop to use special equipment. For this reason, it is often advantageous if the wear elements are fixed mechanically and that a locking device, for example a pin, is used for this.

Usually the wear element has a cavity in which a nose arranged in the support (for example, the adapter) is housed, on which the wear element will be mounted. A through hole passes through the nose, defining a housing, and at least one of the walls of the cavity has a hole in such a way that, in a mounted position, the hole or holes in the walls of the cavity are superimposed (i.e. , aligned or overlapped) with the housing and the locking device (which is substantially an elongated pin) can be inserted through the hole in the wall of the cavity until it is received in the housing. In the mounted position, the locking device partially protrudes from the housing and occupies (at least partially) the hole in the wall of the cavity. This locks the wear element in the mounted position. This overlap (or ali- neation or overlap) does not have to be total, being sufficient that there is a partial overlap as long as it is sufficient for the insertion of the pin. This is also valid in the present invention. In certain cases it is the wear element that has a nose and the support that has a cavity in which, in the mounted position, the nose is housed, but otherwise the rest of the concept works in the same way.

The locking elements indicated above are known, such as that described in EP 1 741 842 A1, for example.

However, in certain cases it has been observed that the blocking devices of the state of the art have drawbacks. Thus, for example, it would be desirable to have locking devices that can be fully housed inside the housing before positioning the wear element on top of the nose of the bracket, as this facilitates mounting and dismounting of the locking device. , particularly in those cases in which the wear elements are very close to each other. In other cases, it is important that the locking device (or the tip of the locking device that is in contact with the wear element) is not subjected to a force that pushes it against the wear element, that is, that the dis - positive locking works independently of the wear element. On the other hand, there is always the need to make the locking devices as cheap and simple as possible.

Presentation of the invention

The object of the invention is to overcome these drawbacks. This purpose is achieved by means of a locking device of the type indicated at the beginning, characterized in that the locking device comprises: - a locking element with a locking end and an inner end opposite the locking end,

- an internal element,

- a displacement means capable of displacing the locking element with respect to the internal element, in a reversible way, between a retracted (or retracted) position and an extended (or deployed) position, where the displacement between the retracted position and the extended defines a direction of travel, and

- elastic means which, in the extended position, exert a force in the direction of the movement direction and tending to bring the locking element closer to the internal element. One of the additional advantages of the present invention is that its configuration facilitates disassembly, since the force of the elastic means facilitates the folding (or retracting) of the locking device.

Another advantage of the present invention is in the fact that the locking device is inside the housing of the support, since the user does not have to remove the locking device when changing the wear element, but can remove the element wear and fit a new one without tampering with the locking device. This is particularly interesting since it is often not necessary to change the locking device (which can remain operative) when the wear element is changed, which allows the consequent cost savings.

Preferably, the locking device comprises a capsule that houses the internal element and at least the internal end of the locking element. It is particularly advantageous that, in the retracted position, the locking element is also fully housed inside the capsule. Furthermore, it is advantageous for the capsule to have a cross section which, in at least one area, is larger than the hole in the wear element. In this way, in the mounted position prevents the capsule from slipping out of the holder housing and not being able to pass through the hole.

Advantageously the elastic elements are a spring, although other elastic elements are possible.

Preferably the displacement means comprise rotating means. The turning means transform a turn into a longitudinal movement. Advantageously, the locking element is a cylindrical body with a base facing the internal element and the internal element is also a cylindrical body with a base facing the locking element. This geometry of both elements allows a particularly advantageous embodiment of the turning means in which the base of the internal element facing the locking element comprises a first inclined surface and the base of the locking element facing the internal element comprises a second inclined surface , where, in the retracted position, both inclined surfaces are superimposed on each other and during a movement between the retracted position and the extended position, the second inclined surface slides on the first inclined surface causing the locking element to move relative to the internal element. In other words, thanks to the inclined surfaces, a rotary movement can be transformed into a linear movement according to the direction of movement. In this embodiment, the force exerted by the elastic means tends to bring the first inclined surface and the second inclined surface together.

In the above case, a preferred embodiment is when the base of the internal element facing the blocking element comprises a first seating surface arranged at the end of the first inclined surface which, in the extended position, is closer to the element locking element, and the base of the locking element facing the internal element comprises a second seating surface arranged at the end of the second inclined surface which, in the extended position, is closest to the internal element, where, in the exposed position When laid, both seating surfaces are superimposed on each other. In this way it is achieved that the extended position is a stable position and the locking device does not tend to retract towards the retracted position due to the force exerted by the elastic means. It is particularly advantageous if one of the seating surfaces comprises a first elevation at the end of the seating surface opposite the junction area between the seating surface and its corresponding inclined surface. This first lift thus defines an “end of run” and prevents the turn from continuing beyond what is planned. Another particularly advantageous solution is found when one of the seating surfaces has a second elevation at the end of the seating surface close to the junction area between the seating surface and its corresponding inclined surface. This second elevation prevents, for example due to vibrations and shocks to which the wear element is subjected, the locking element and the internal element from rotating relative to each other until the seating surfaces are no longer in contact. contact with each other, with the subsequent risk of the locking device retracting due to the force generated by the elastic means. The second elevation must be dimensioned in such a way as to avoid this involuntary twist but to allow the voluntary twist made to want to retract the locking device.

Also in the previous case, another preferred form of embodiment is when the base of the internal element facing the locking element comprises a first guiding surface opposite the first inclined surface and the base of the locking element facing the internal element comprises a second guide surface opposite the second inclined surface, where, in the retracted position the first guide surface and the second guide surface are superimposed on each other and during a movement between the retracted position and the extended position the second guide surface is slide to the lake of the first guidance surface. In this case, by indicating that each guiding surface is opposite to its corresponding inclined surface what is meant is that both surfaces have an orientation in space that is in the same direction, but in opposite directions. As will be seen below, in the examples shown in Figs., At some some cases the inclined surface and its corresponding guiding surface will face each other, while in other cases they will be on opposite sides of a projection, that is, they will have "their backs" facing each other. With this orientation of the two guide surfaces (opposite to the corresponding inclined surfaces), the force exerted by the elastic means tends to separate one guide surface from the other. This embodiment makes it possible to facilitate the folding of the locking device, since the guide surfaces guide the locking element when it moves from the extended position to the retracted position. This form of realization is compatible with the additional improvements indicated in the previous paragraph. Additionally, in the case that the embodiment includes a second elevation as indicated above, then another additional improvement is obtained when the second elevation has a point of maximum elevation that has a maximum height, in the direction of travel, relative to the seating surface, and the guiding surface corresponding to the incline surface corresponding to the seating surface extends, in the direction of travel, beyond the point of maximum elevation. In this way, the guiding surface exerts its guiding function from the first instant of the folding movement, which is when the second elevation is exceeded. Preferably the transition from the retracted position to the extended position is achieved by rotating the locking element relative to the internal element by 360 ° or less, preferably by 180 ° or less, and most preferably by 90 °.

Advantageously, the turning means comprise a hole arranged in the base of the locking element opposite the internal element, where the hole is coaxial with the direction of movement and does not have a cylindrical symmetry according to the direction of movement.

Preferably the locking device comprises anti-rotation means, capable of preventing its rotation with respect to the support. These anti-rotation means are advantageously arranged in the capsule. Preferably, the blocking device comprises air evacuation means that communicate the space between the blocking element and the internal element with the outside. Indeed, in certain cases the air remaining in this space is compressed when folding the locking device and generates an overpressure that makes it difficult (and even prevents) from folding. The air evacuation means allow the air trapped in this space to be evacuated, preventing an overpressure from being generated in this space.

Advantageously, the locking device comprises an O-ring at an intermediate point of the lateral surface of the locking element. The purpose of this O-ring seal is to prevent dust and / or fines from getting inside the wear device during the operation of the earthmoving machine (in the present description, fines are understood as small particles). However, this O-ring can increase the risk of the above-mentioned overpressure being generated. Therefore, it is particularly advantageous if the air evacuation means comprise an air evacuation duct that extends between the space between the locking element and the internal element and an upper end, where the upper end of the air duct Air evacuation is below, according to the direction of travel, the O-ring when the locking element and the internal element are in the extended position, and is above, according to the direction of travel, the O-ring when the element lock and inner element are in the stowed position. In this way, when the blocking device is extended, the upper end of the evacuation duct is "behind" the O-ring and the entry of dust and / or fines into the interior of the blocking element is avoided, but start the folding of the blocking element, the upper end of the evacuation duct is above the O-ring, in such a way that the air can escape from the space between the blocking element and the internal element and the generation of an overpressure that makes it difficult or impossible to fold back the locking device. Preferably the air evacuation duct is a cavity arranged between the outer lateral surface of the blocking element and the lateral surface of said cap. A preferred form of embodiment of a locking device according to the invention is when the device comprises a stem with a first end fixed to the internal element and a second end housed inside a cavity arranged in the locking element, where the second end is able to move according to the direction of movement along the cavity, where the cavity has an opening facing the internal element and is traversed by the stem, and where the elastic means are arranged between the second end stem and opening. In this case, it is particularly advantageous that the first end of the stem is fixed (and preferably screwed) to the internal element. It is also particularly advantageous that the locking element has a mounting hole coaxial with the direction of travel and with a diameter greater than the maximum diameter of the stem so that the stem is able to be housed in the cavity through the mounting hole. . In fact, the stem preferably has a head at its end that acts as a stop for the elastic means, where this head is the one that defines the maximum diameter of the stem. It is also advantageous if the device comprises a plug that closes the mounting hole, to prevent the entry of dust and stones through the mounting hole.

Another preferred embodiment of a locking device according to the invention, equivalent to the previous one but "inverted", is when the locking device comprises a stem with a first end fixed to the locking element and a second end housed in the interior of a cavity arranged in the internal element, where the second end is capable of moving according to the direction of movement along the cavity, where the cavity has an opening facing the locking element and is traversed by the stem , and where the elastic means are arranged between the second end of the stem and the opening. As in the previous case, it is advantageous that the first end of the rod is screwed to the locking element, that the internal element has a mounting hole coaxial with the direction of travel and with a diameter greater than the maximum diameter of the stem so that the stem is able to be housed in the cavity through the mounting hole, and that the device comprises a plug that closes the mounting hole .

In general, the elastic means can be considered to have a length D in a load-free state, measured in the direction of displacement, and are capable of being compressed to a maximum length T, measured in the direction of displacement. , and that the locking element and the internal element are separated by a distance E when moving from the retracted position to the extended position, measured in the direction of said direction of travel. Advantageously, the difference between D and T is greater than or equal to E. In this way it is ensured that the elastic means are not compressed beyond their admissible value. In general, one of the advantages of the present invention is that the elastic means exert a force that helps to retract the locking device. This makes it possible to have another advantageous solution, which is achieved when the elastic means are in a partially compressed state when the locking element and the inner element are in the retracted position. In this way it is ensured that the elastic means are exerting a force during the entire travel between the deployed position and the retracted position, which ensures that the locking element reaches the fully retracted position (that is, the risk of it being slightly deployed is avoided, which could occur if the elastic means cease to exert any force in the retracted position). Additionally, it is also achieved that the elastic means prevent the locking device from moving from its folded position in an undesired way, during its manipulation in an undesired way. In this case, taking into account the definition of T and E indicated above and considering that the elastic means in the partially compressed state have a length P, measured in the direction of said direction of displacement, then it is advantageous that the difference between P and T is greater than or equal to E, to ensure that the elastic means are not compressed beyond their allowable value. Another advantageous embodiment of the invention is when the locking device comprises:

- a second blocking element equal to the aforementioned blocking element,

- second displacement means equal to the aforementioned displacement means and capable of displacing the second locking element with respect to the internal element, in a reversible way, between a retracted position and an extended position, where the displacement between the retracted position and the extended position takes place in the same direction of travel indicated above,

- second elastic means equal to the elastic means indicated above which, in the extended position, exert a force in the direction of the movement direction and tending to bring the second locking element closer to the internal element.

In essence, this latter embodiment consists of a locking device that extends from both ends. It is common for the housing in the nose of the bracket to be a through hole and for the wear element to have two holes, each on opposite walls of the cavity. In these cases, it is important for the locking device to be fitted in both holes, so that the wear element is blocked at two points. This last embodiment makes it possible to achieve this objective.

Brief description of the drawings

Other advantages and characteristics of the invention can be seen from the following description, in which, without any limitation, some preferred modes of carrying out the invention are related, mentioning the accompanying drawings. Figures show: Fig. 1, a perspective view of a wear element partially mounted on a support and an exploded view of a first embodiment of a locking device according to the invention.

Figs. 2 to 5, a perspective view and top, front and side views, respectively, of the locking device of Fig. 1 in an extended (or unfolded) position.

Figs. 6 and 7, front and side views, respectively, of the locking device of Figures 2 to 5, without the capsule.

Fig. 8, a view equivalent to Fig. 6, but with the locking device in the retracted position. Fig. 9, a longitudinal section view, according to the direction of movement, of the locking device of Fig. 8.

Fig. 10, a longitudinal section view, according to the direction of movement, of the locking device of Fig. 6.

Fig. 11, a perspective view of a support into which two locking elements are inserted according to the invention.

Fig. 12, an exploded view of a second embodiment of a locking device according to the invention.

Fig. 13, a top view of the locking device of Fig. 12.

Fig. 14, a longitudinal section view, according to the direction of movement, of the locking device of Fig. 12 in the folded position. Fig. 15, a longitudinal section view, according to the direction of movement, of the locking device of Fig. 12 in the extended position.

Figs. 16-18, details relating to an air evacuation system according to the invention.

Fig. 19, a perspective view of another embodiment of a locking device, without the capsule Fig. 20, a perspective view of the internal element of the locking device of Fig. 19.

Detailed description of some embodiments of the invention

In Figs. 1 to 10 a first embodiment of a retention device according to the invention is shown. The device comprises a locking element 1, an internal element 2, a stem 3, a spring 4 and a closing element 5. The locking element 1 has an O-ring 6 that extends along its perimeter side. These components are housed inside a capsule 7. When the locking device is in the extended position, a locking end 8 of the locking element 1 protrudes from the capsule 7 (see Figs. 2, 4 and 5).

The device is housed in a housing 9 provided in the nose of a support 10 (in Fig. 1, a welding nose (known as "Weld on nose")). Next, a wear element 11 (in Fig. 1, a tooth) is positioned above the support 10. The wear element 11 has a cavity suitable to house the nose of the support 10 inside and has a hole 12 in one of the side walls of the cavity. In the assembled position, the hole 12 is at least partially overlapped with the housing 9 such that the locking end 8 can protrude from the housing. 9 and lodge in the hole 12, which causes the blocking of the wear element 11 in the support 10.

The locking element 1 and the internal element 2 are substantially cylindrical bodies capable of being housed inside the capsule 7, which is also cylindrical. The two cylindrical bodies are arranged in such a way that their axes coincide (and coincide with the direction of movement). Therefore, the cylindrical body that makes up the locking element 1 has a base facing a base of the cylindrical body that makes up the internal element 2.

The internal element 2 is welded to the capsule 7 at the bottom of both (see figs. 14 and 15), so that it is fixed with respect to the capsule 7, while the locking element 1 can rotate with respect to the capsule 7. For its part, the capsule 7 has a lateral projection 14 that prevents the capsule 7 from rotating with respect to the housing 9. This lateral projection 14 thus defines anti-rotation means.

In this first embodiment, the displacement means comprise rotating means. The turning means include a first inclined surface 15 arranged at the base of the internal element 2 facing the locking element 1 and a second inclined surface 16 at the base of the locking element 1 facing the internal element 2. The first and the second Inclined surface 15 and 16 have a helical configuration, so that they can slide relative to each other as locking element 1 rotates relative to internal element 2. Due to this helical configuration, the rotation also causes a displacement in sense of the axis of the helical surface, which is thus the direction of displacement. In fact, the inner element 2 has two first inclined surfaces 15 and the locking element 1 also has two second inclined surfaces 16, so that each first inclined surface 15 is paired with a second inclined surface 16.

At the end of each inclined surface 15 and 16 is a settlement surface 17 (the first settlement surface and the second settlement surface, respectively). valy). When the locking device is in its extended position (see Figs. 6 and 7), the locking element 1 and the internal element 2 are supported against each other through their respective seating surfaces 17, thus defining a locking position. stable.

The seating surface 17 of the internal element 2 comprises a first elevation 18 at the end opposite the junction area between the seating surface 17 and the first inclined surface 15. This first elevation 18 prevents it from being inadvertently rotated locking member 1 beyond this point, causing it to retract abruptly. The seating surface 17 of the internal element 2 also comprises a second elevation 19 at the end close to the connection zone between the seating surface 17 and the first inclined surface 15. In this case, this second elevation 19 has as its object to avoid that, due to the vibrations and shocks to which the locking device is subjected during use, the locking element 1 can move from the stable position defined by the seating surfaces 17 and retract due to the force of the elastic media.

As can be seen, in this first embodiment, the change from the folded to the detached position (and vice versa) is achieved by turning 90 ° (a quarter turn). To perform this rotation, the base of the locking element 1 which is at the locking end 8, that is, the base opposite the internal element 2, has a hole 20 suitable for inserting a turning tool. This hole 20 is shaped in a substantially square cross section.

The elastic means comprise a helical spring 4. The spring 4 is mounted around a stem 3. The stem 3 has a first end 21 fixed to the internal element 2 by means of a screw 13. The second end 23 of the stem 3 is housed inside a cavity 24 arranged in the element of lock 1 and is capable of moving in the direction of travel along the cavity 24 when the locking device is extended or retracted. The second end 23 has a head 25 that retains the spring 4. The cavity 24 has an opening 26 oriented towards the internal element 2 and is traversed by the stem 3. The opening 26 is smaller than the spring 4, so that the spring 4 is retained between the head 25 and the opening 26. To facilitate assembly of the assembly, the The opening 26 is in a closing element 5 that is screwed to the locking element 1. The closing element 5 is larger in diameter than the head 25, so that the head 25 and the spring 4 can be inserted into the cavity 24 and subsequently screwing the closure element 5 into the locking element 1.

In the present description and claims, all the displacements between the different elements of the device have been indicated in relative terms and for the sole purpose of explaining the operation of the device. In reality, the inner element 2 is fixed to the capsule 7 (for example, welded) and the capsule 7 is fitted into the housing 9, since it is larger than the hole 12. Therefore, what actually moves with respect to the support 10 and the wear element 11 it is the locking element 1.

In Figs. 12 to 18 a second embodiment of a locking device according to the invention is shown. The main difference between this second embodiment and the one described above lies in the fixing of the stem 3 and the way of mounting it in the device. In this case, the locking element 1 has a mounting hole 27 coaxial with the direction of travel and with a diameter greater than the maximum diameter of the stem 3 (that is, the maximum diameter defined by the head 25). In this way the stem 3 can be housed in the cavity 24 by inserting it through the mounting hole 27. The end of the stem 3 opposite the head 25 is threaded and passes through the opening 26 (which, in this case, is smaller than the spring 4, since spring 4 is also inserted into cavity 24 through mounting hole 27). This threaded end can be screwed to the internal element 2, in such a way that the assembly remains assembled. A plug 28 closes the mounting hole 27. In both embodiments shown, the locking element is larger than the internal element and cavity in which the head of the stem is housed and the spring is in the locking element. However, it would be possible to design a locking device in which the stem was fixed to the locking element and the internal element was large enough to house a cavity inside it that contained the head of the stem and the spring, that is, a "symmetrical" configuration to that shown in the examples above.

The second embodiment of Figs. 12 to 18 also includes air evacuation means that communicate the space between the blocking element 1 and the internal element 2 with the outside. However, these air evacuation means could have been included exactly the same in the first embodiment or in the "symmetric" embodiments indicated above.

These air evacuation means are intended to prevent the overpressure generated in the space between the locking element 1 and the internal element 2 when attempting to retract the locking device. The O-ring 6 makes it difficult for air to pass from this interior space to the exterior. To avoid this overpressure, the blocking device includes an air evacuation duct 29 that extends between this interior space and an upper end 30 of the air evacuation duct 29. The position of this upper end 30 is important. The purpose of the O-ring 6 is to prevent dust and / or fines from entering the interior of the locking device. Therefore, when the locking device is extended it is important that the O-ring 6 can exert its function, so the upper end 30 of the air evacuation duct 29 must be "below" the O-ring 6 (see Fig. 15 and enlarged detail of Fig. 17). When the locking device is retracted, the upper end 30 of the air evacuation duct 29 must be "above" the O-ring 6, so that a communication is established between the interior and exterior space that allows the air to escape. (see Fig. 14 and enlarged detail of Fig. 16). The most advantageous thing is that the upper end 30 of the air evacuation duct 29 is close (below) to the O-ring 6 when the locking device is extended, in such a way that, when the folding begins, the upper end 30 remains quickly above the O-ring 6 and the overpressure generated in the interior space is as low as possible. The air evacuation duct 29 has been formed from a cavity or clearance between the outer lateral surface of the locking element 1 and the inner lateral surface of the capsule 7. Specifically, the inner lateral surface of the capsule 7 is not totally cylindrical but rather has a section (corresponding to the air evacuation duct 29) that is oval or ellipsoidal (see Fig. 18, which schematically shows a cross section of the locking element 1 and the capsule 7). In this way, between both side surfaces there is a clearance that is sufficient to allow the passage of air. In any case, this clearance must be large enough to ensure that the O-ring 6 no longer exerts a tight seal.

In Figs. 19 and 20 another embodiment of a locking device according to the invention is shown. The same references have been used for those elements that are common with the previous embodiments. In this new embodiment the main difference lies in the fact that the base of the internal element 2 facing the locking element 1 comprises a first guiding surface 31 opposite the first inclined surface 15 and the base of the locking element 1 facing the internal element 2 comprises a second guiding surface 32 opposite to the second inclined surface 16. That is, the locking element 1 has a helical finger 33 that is capable of being housed in a helical housing 34 arranged in the internal element 2. The Helical finger 33 defines the second inclined surface 16 and the second guide surface 32, which are on opposite sides of the helical finger 33. For its part, the helical housing 34 defines the first inclined surface 15 and the first guide surface 31, which are two facing faces of the helical housing 34.

As seen in Fig. 19, in the retracted position the first guide surface 31 and the second guide surface 32 are superimposed on each other. As the locking member 1 is rotated to its extended position, the second guide surface 32 slides along the first guide surface 31.

In general, the second elevation 19 has a point of maximum elevation 35 (in the solution shown in the figures it is an entire edge) that has a maximum height, in direction of travel direction, with respect to the seating surface 17. This maximum height is determined in such a way as to ensure that the locking element 1 cannot "jump" from the seating surface 17 to the first inclined surface 15 but which is low enough so that it can be overcome when bringing the locking element 1 to its extended position. The first guide surface 31 (which is the one that corresponds to the first inclined surface 15 which is, in turn, the one that corresponds to the first seating surface 17) extends, in the direction of movement, beyond the point of maximum lift 35. In this way it is ensured that, when the locking element 1 is in its extended position and the rotation is started to bring the locking element 1 to its retracted position, the two guide surfaces 31 and 32 immediately enter in contact as soon as the locking element 1 has passed the point of maximum elevation (35 of the second elevation 19. An example is shown in Fig. 11 in which two locking devices are used to secure a wear element However, it would also be possible to use a locking device that, having a single internal element, has two locking elements that extend on each side of the internal element, as mentioned above. .

Claims

1 - Locking device to hold a wear element (11) on a support (10) in an earth moving machine, said support (10) comprising a housing (9) and said wear element comprising a hole (12) so that, in an assembled position, said housing (9) and said hole (12) are at least partially aligned, wherein said locking device is capable of being inserted into said housing (9), characterized in that said device block includes:

- a locking element (1) with a locking end (8) and an internal end opposite said locking end (8),

- an internal element (2),

- a displacement means suitable for displacing said locking element (1) with respect to said internal element (2), in a reversible way, between a retracted position and an extended position, where the displacement between said retracted position and said extended position defines a direction of travel, and

- elastic means that, in said extended position, exert a force in the direction of said direction of movement and tending to bring said locking element (1) closer to said internal element (2).

2 - Device according to claim 1, characterized in that it comprises a capsule (7) that houses said internal element (2) and at least said internal end of said blocking element (1).

3 - Device according to one of claims 1 or 2, characterized in that said elastic elements are a spring (4). 4 - Device according to any of claims 1 to 3, characterized in that said means of movement comprise means of rotation.

5 - Device according to any of claims 1 to 4, characterized in that said locking element (1) is a cylindrical body with a base facing said internal element (2) and said internal element (2) is a cylindrical body with a base facing said locking element (1).

6 - Device according to claim 5, characterized in that the base of said internal element (2) facing said blocking element (1) comprises a first inclined surface (15) and the base of said blocking element (1) Facing said internal element (2) comprises a second inclined surface (16), where, in said folded position, both inclined surfaces are superimposed on each other and during a displacement between said folded position and said extended position said second inclined surface (16) it slides on said first inclined surface (15) causing said locking element (1) to move relative to said internal element (2).

7 - Device according to claim 6, characterized in that the base of said internal element (2) facing said blocking element (1) comprises a first seating surface (17) arranged at the end of said first inclined surface ( 15) which, in said extended position, is closer to said locking element (1), and the base of said locking element (1) facing said internal element (2) comprises a second seating surface (17) arranged at the end of said second inclined surface (16) which, in said extended position, is closer to said internal element (2), where, in said extended position both seating surfaces (17) are superimposed on each other.

8 - Device according to claim 7, characterized in that one of said seating surfaces (17) comprises a first elevation (18) at the end of said seating surface (17) opposite the junction area between said surface. settlement (17) and its corresponding inclined surface. 9 - Device according to one of claims 7 or 8, characterized in that one of said seating surfaces (17) comprises a second elevation (19) at the end of said seating surface (17) close to the junction area between said seating surface (17) and its corresponding inclined surface.

10 - Device according to any of claims 6 to 9, characterized in that the base of said internal element (2) facing said locking element (1) comprises a first guiding surface (31) opposite said first inclined surface (15 ) and the base of said locking element (1) facing said internal element (2) comprises a second guiding surface (32) opposite said second inclined surface (16), where, in said folded position, the first guiding surface (31) and the second guide surface (32) are superimposed on each other and during a displacement between said folded position and said extended position said second guide surface (32) slides along said first guide surface ( 31).

11 - Device according to claims 9 and 10, characterized in that said second elevation (19) has a point of maximum elevation (35) that has a maximum height, in the direction of said direction of movement, with respect to said seating surface ( 17), and because the guiding surface corresponding to the inclined surface corresponding to said seating surface extends, in said direction of movement, beyond said point of maximum elevation (35). 12 - Device according to any of claims 4 to 11, characterized in that the passage from said retracted position to said extended position is achieved by rotating said locking element (1) with respect to said internal element (2) of 360 ° or less, preferably 180 ° or less, and most preferably 90 °. 13 - Device according to any of claims 4 to 12, characterized in that said turning means comprise a hole (20) arranged at the base of said locking element (1) opposite said internal element (2), where said hole is coaxial with said direction of movement and does not have cylindrical symmetry according to said direction of movement.

14 - Device according to any of claims 4 to 13, characterized in that it comprises anti-rotation means, suitable to prevent its rotation with respect to said support (10).

15 - Device according to any of claims 1 to 14, characterized in that it comprises air evacuation means that communicate the space between said blocking element (1) and said internal element (2) with the outside.

16 - Device according to any of claims 1 to 15, characterized in that it comprises an O-ring (6) at an intermediate point of the lateral surface of said locking element (1).

17 - Device according to claims 15 and 16, characterized in that said air evacuation means comprise an air evacuation duct (29) that extends between said space between said blocking element (1) and said internal element ( 2) and an upper end (30), where said upper end (30) of said air evacuation duct (29) is below, according to said direction of movement, said O-ring (6) when said blocking element

(1) and said internal element (2) are in said extended position, and is above, according to said direction of movement, said O-ring (6) when said locking element (1) and said internal element (2) they are in said stowed position.

18 - Device according to claim 17, characterized in that said air evacuation duct (29) is a cavity arranged between the outer lateral surface of said blocking element (1) and the lateral surface of said jacket. 19 - Device according to any of claims 1 to 18, characterized in that it comprises a stem (3) with a first end (21) fixed to said internal element

(2) and a second end (23) housed inside a cavity (24) arranged in said blocking element (1), where said second end (23) is able to move according to said direction of movement along said cavity (24), where said cavity (24) has an opening (26) oriented towards said internal element (2) and is traversed by said stem (3), and where said elastic means are arranged between said second end (23) of said stem (3) and said opening (26).

20 - Device according to claim 19, characterized in that said first end (21) of said stem (3) is screwed to said internal element (2).

21 - Device according to one of claims 19 or 20, characterized in that said locking element (1) has a mounting hole (27) coaxial with said direction of movement and with a diameter greater than the maximum diameter of said rod (3) so that said stem (3) is able to be housed in said cavity (24) through said mounting hole (27).

22 - Device according to claim 21, characterized in that it comprises a plug (28) that closes said mounting hole (27). 23 - Device according to any of claims 1 to 18, characterized in that it comprises a stem (3) with a first end (21) fixed to said blocking element (1) and a second end (23) housed inside the a cavity (24) arranged in said internal element (2), where said second end (23) is able to move according to said direction of movement along said cavity (24), where said cavity (24) has a opening (26) oriented towards said locking element (1) and is traversed by said stem (3), and where said elastic means are arranged between said second end (23) of said stem (3) and said opening (26) . 24 - Device according to claim 23, characterized in that said first end

(21) of said stem (3) is screwed to said locking element (1). 25 - Device according to one of claims 23 or 24, characterized in that said internal element (2) has a mounting hole (27) coaxial with said direction of movement and with a diameter greater than the maximum diameter of said stem (3) so that said stem (3) is able to be housed in said cavity (24) through said mounting hole (27).

26 - Device according to claim 22, characterized in that it comprises a plug (28) that closes said mounting hole (27). 27 - Device according to any of claims 1 to 26, characterized in that said elastic means have a length D in a state free of loads, measured in the direction of said direction of movement, and are capable of being compressed up to a maximum length T, measured in the direction of said displacement direction, and said locking element (1) and said internal element (2) are separated by a distance E when moving from said retracted position to said extended position, measured in the direction of said direction displacement, and where the difference between D and T is greater than or equal to E.

28 - Device according to any of claims 1 to 27, characterized in that said elastic means are in a partially compressed state when said locking element (1) and said internal element (2) are in said retracted position.

29 - Device according to claim 28, characterized in that said elastic means in said partially compressed state have a length P, measured in the direction of said direction of movement, and are capable of being compressed at most up to a length T, measured in the direction of said direction of movement, and said locking element (1) and said internal element (2) are separated by a distance E when moving from said retracted position to said extended position, measured in the direction of said direction of movement, and where the difference between P and T is greater than or equal to E. 30 - Device according to any of claims 1 to 29, characterized in that it comprises:

- a second blocking element equal to said blocking element (1),

- second displacement means equal to said displacement means and capable of displacing said second locking element with respect to said internal element (2), in a reversible way, between a retracted position and an extended position, where the displacement between said folded position and said extended position takes place in said direction of travel,

- second elastic means equal to said elastic means which, in said extended position, exert a force in the direction of said direction of movement and tending to bring said second locking element closer to said internal element (2).