Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
LOCKING DEVICE FOR COUPLING A WEAR ELEMENT TO A SUPPORT IN AN EARTH MOVING MACHINE
Document Type and Number:
WIPO Patent Application WO/2020/201418
Kind Code:
A1
Abstract:
The present invention relates to a locking device for coupling a wear element (11) to a support (10) in an earth moving machine, having a housing (9) in the support (10) and a hole (12) in the wear element such that, in an assembled position, the housing (9) and the hole (12) are at least partially aligned. The locking device is introduced inside the housing (9), and comprises: - a locking element (1), - an internal element (2), - movement means suitable for moving 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, in which the locking element is completely within the housing and completely outside the hole, and an extended position, and - elastic means which, in the extended position, exert a force that tends to move the locking element (1) closer to the internal element (2).

Inventors:
LÓPEZ ALMENDROS JOSÉ (ES)
BOBOUH ABAKOUY KAMAL (ES)
ORTIZ GARCÍA JUSTO JESÚS (ES)
Application Number:
PCT/EP2020/059389
Publication Date:
October 08, 2020
Filing Date:
April 02, 2020
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
METALOGENIA RESEARCH & TECH SL (ES)
International Classes:
E02F9/28
Domestic Patent References:
WO1997021880A11997-06-19
Foreign References:
AU2017202334A12017-04-27
US4664450A1987-05-12
EP2952639A12015-12-09
EP1741842A12007-01-10
Attorney, Agent or Firm:
CURELL AGUILÁ, Mireia et al. (ES)
Download PDF:
Claims:
CLAIMS

1 - A locking device for coupling a wear element (11) to a support (10) in an earth moving machine, said support (10) comprising a housing (9) and said wear element comprising a

5 hole (12) such that, in an assembled position, said housing (9) and said hole (12) are at least partially aligned, where said locking device is suitable for being introduced inside said housing (9), characterized in that said locking device comprises:

- a locking element (1) with a locking end (8) and an internal end opposite said locking end 10 (8),

- an internal element (2),

- movement means suitable for moving said locking element (1) with respect to said internal

15 element (2), in a reversible manner, between a retracted position and an extended position, where the movement between said retracted position and said extended position defines a direction of movement, and

- elastic means which, in said extended position, exert a force in the direction of said direction

20 of movement that tends to move said locking element (1) closer to said internal element (2).

2 - The device according to claim 1 , characterized in that it comprises a capsule (7) housing therein said internal element (2) and at least said internal end of said locking element (1).

25 3 - The device according to one of claims 1 or 2, characterized in that said elastic means are a spring (4).

4 - The device according to any one of claims 1 to 3, characterized in that said movement means comprise rotation means.

30

5 - The device according to any one 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 - The device according to claim 5, characterized in that the base of said internal element (2) facing said locking element (1) comprises a first inclined surface (15) and the base of said locking element (1) facing said internal element (2) comprises a second inclined surface (16),

5 where, in said retracted position, both inclined surfaces are superimposed on one another and during a movement between said retracted position and said extended position, said second inclined surface (16) slides over said first inclined surface (15), causing the movement of said locking element (1) with respect to said internal element (2).

10 7 - The device according to claim 6, characterized in that the base of said internal element

(2) facing said locking 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

15 (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 one another.

8 - The 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

20 attachment area between said seating surface (17) and its corresponding inclined surface.

9 - The 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 attachment area between said seating surface (17) and its corresponding inclined

25 surface.

10 - The device according to any one of claims 6 to 9, characterized in that the base of said internal element (2) facing said locking element (1) comprises a first guide surface (31) opposite said first inclined surface (15) and the base of said locking element (1) facing said

30 internal element (2) comprises a second guide surface (32) opposite said second inclined surface (16), where, in said retracted position the first guide surface (31) and the second guide surface (32) are superimposed on one another and during a movement between said retracted position and said extended position, said second guide surface (32) slides along

- said first guide surface (31).

1 1 - The device according to claims 9 and 10, characterized in that said second elevation (19) has a maximum elevation point (35) having a maximum height, in the sense of said

5 direction of movement, with respect to said seating surface (17), and in that the guide surface corresponding to the inclined surface corresponding to said seating surface extends, in said direction of movement, beyond said maximum elevation point (35).

12 - The device according to any one of claims 4 to 11 , characterized in that the transition

10 from said retracted position to said extended position is achieved by means of a rotation of said locking element (1) with respect to said internal element (2) of 360° or less, preferably 180° or less, and very preferably 90°.

13 - The device according to any one of claims 4 to 12, characterized in that said rotation

15 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 present cylindrical symmetry according to said direction of movement.

14 - The device according to any one of claims 4 to 13, characterized in that it comprises

20 anti-rotation means, suitable for preventing rotation thereof with respect to said support (10).

15 - The device according to any one of claims 1 to 14, characterized in that it comprises air discharge means communicating the space comprised between said locking element (1) and said internal element (2) with the outside.

25

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

17 - The device according to claims 15 and 16, characterized in that said air discharge means

30 comprise an air discharge conduit (29) extending between said space comprised between said locking element (1) and said internal element (2) and an upper end (30), where said upper end (30) of said air discharge conduit (29) is, according to said direction of movement, below said O-ring (6) when said locking element (1) and said internal element (2) are in said

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

18 - The device according to claim 17, characterized in that said air discharge conduit (29)

5 is a cavity arranged between the outer side surface of said locking element (1) and the side surface of said sleeve.

19 - The device according to any one of claims 1 to 18, characterized in that it comprises a rod (3) with a first end (21) fixed to said internal element (2) and a second end (23) housed

10 inside a cavity (24) arranged in said locking element (1), where said second end (23) is suitable for being moved 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 with said rod (3) going through same, and where said elastic means are arranged between said second end (23) of said rod (3) and said opening (26).

15

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

21 - The device according to one of claims 19 or 20, characterized in that said locking element

20 (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) such that said rod (3) is suitable for being housed in said cavity (24) through said mounting hole (27).

22 - The device according to claim 21 , characterized in that it comprises a plug (28) closing

25 said mounting hole (27).

23 - The device according to any one of claims 1 to 18, characterized in that it comprises a rod (3) with a first end (21) fixed to said locking element (1) and a second end (23) housed inside a cavity (24) arranged in said internal element (2), where said second end (23) is

30 suitable for being moved according to said direction of movement along said cavity (24), where said cavity (24) has an opening (26) oriented towards said locking element (1) and with said rod (3) going through same, and where said elastic means are arranged between said second end (23) of said rod (3) and said opening (26).

- 24 - The device according to claim 23, characterized in that said first end (21) of said rod (3) is screwed to said locking element (1).

5 25 - The 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 rod (3) such that said rod (3) is suitable for being housed in said cavity (24) through said mounting hole (27).

10 26 - The device according to claim 23, characterized in that it comprises a plug (28) closing said mounting hole (27).

27 - The device according to claim 2 or any one of claims 3 to 18 when depending from claim 2, characterized in that it comprises a rod (3) with a first end (21) fixed to said locking element

15 (1) and a second end (23) housed inside a hollow space (36) arranged in said capsule (7) between said internal element (2) and an inner end (37) of said capsule (7) opposed to an open end (38) of said capsule (7), where said second end (23) is suitable for being moved according to said direction of movement along said hollow space (36), where said internal element (2) has a central opening (39) communicating said locking element (1) with said

20 hollow space (36) and with said rod (3) going through said central opening (39), and where said elastic means (4) are arranged between said second end (23) of said rod (3) and said central opening (39).

28 -. The device according to claim 27, characterized in that said first end (21) of said rod (3)

25 is screwed to said locking element (1).

29 - The device according to claim 27, characterized in that said first end (21) of said rod (3) is fixed to said locking element (1) through a hinged joint (40).

30 30 - The device according to any one of claims 1 to 29, characterized in that said elastic means have a length D in an unloaded state, measured in the sense of said direction of movement, and are suitable for being compressed at most to a length T, measured in the sense of said direction of movement, and said locking element (1) and said internal element

- (2) separate a distance E upon moving from said retracted position to said extended position, measured in the sense of said direction of movement, and where the difference between D and T is greater than or equal to E.

5 31 - The device according to any one of claims 1 to 30, 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.

32 - The device according to claim 31 , characterized in that said elastic means in said

10 partially compressed state have a length P, measured in the sense of said direction of movement, and are suitable for being compressed at most to a length T, measured in the sense of said direction of movement, and said locking element (1) and said internal element (2) separate a distance E upon moving from said retracted position to said extended position, measured in the sense of said direction of movement, and where the difference between P

15 and T is greater than or equal to E.

33 - The device according to any one of claims 1 to 32, characterized in that it comprises:

- a second locking element identical to said locking element (1),

20

- second movement means identical to said movement means and suitable for moving said second locking element with respect to said internal element (2), in a reversible manner, between a retracted position and an extended position, where the movement between said retracted position and said extended position takes place in said direction of movement,

25

- second elastic means identical to said elastic means which, in said extended position, exert a force in the direction of said direction of movement that tends to move said second locking element closer to said internal element (2).

30 34 - The device according to any one of claims 1 to 33, characterized in that in said retracted position said locking element (1) is completely within said housing (9) and completely outside of said hole (12).

- 35 - The device according to any one of claims 1 to 34, characterized in that in said extended position said locking end is blocking said wear element, while in said retracted position said locking element is out of the blockage of said wear element.

5

-

Description:
LOCKING DEVICE FOR COUPLING A WEAR ELEMENT TO A SUPPORT IN AN EARTH

MOVING MACHINE

DESCRIPTION

5

Field of the Invention

The invention relates to a locking device for coupling a wear element to a support in an earth moving machine, the support comprising a housing and the wear element comprising a hole

10 such that, in an assembled position, the housing and the hole are at least partially aligned

(that is, partially overlapping), where the locking device is suitable for being introduced inside the housing.

In the present description and claims it has to be understood that, when it is said that“the

15 housing and the hole are at least partially aligned (that is, partially overlapping)”, what is meant is the following:

- the hole defines a hole longitudinal axis

- the housing defines a housing longitudinal axis

20 - in an assembled position, both longitudinal axes are parallel to each other and close to each other or coincident in space

- a cross section of said hole projected according to the hole longitudinal axis overlaps, or, at least partially overlaps, the cross section of said housing

- the hole and the housing are mutually exclusive in the sense that neither the hole includes

25 part of the housing or the whole housing nor the housing includes part of the hole or the whole hole

- the hole and the housing are aligned in the sense that, in a direction according to both longitudinal axes, one of them starts when the other finishes (in the case when there is a complete overlapping). In the case when there is only a partial overlapping, those parts of

30 the hole and the housing that correspond to the overlapping area are aligned.

It must be taken into account that a locking device is designed for a specific support and wear element pair. The designer must therefore know all the details of both the support and

- wear element affecting the locking device. The designer must particularly know the relevant dimensions of both the support and wear element for the design of the locking device. Additionally, it must be taken into account that the wear system is designed to sustain given wear. In this sense, the expected wear of the wear system and how it will affect the locking

5 device and the dimensions of the wear element and of the support affecting the locking device are also known. All these data are“starting information” when a specific locking device has to be designed. Therefore, it must be considered that all this information“is part of the locking device itself” since they are pre-established values for the design thereof. So, although the claims may define an entity (e.g., the locking device as such), it is admissible

10 that they refer to the wear element, the support or parts thereof when defining the locking device, as, in fact, the relevant data of the wear element and the support are implicitly part of the locking device as such.

15 State of the Art

Earth moving machines are used in excavation, demolition, construction, mining, and dredging works and similar activities. They generally have a shovel or bucket where the material is collected. The shovel or bucket is subjected to high stresses and erosion,

20 particularly in the area of the lip (also referred to as blade). As a result, the shovel or bucket usually has a plurality of wear elements protecting it against wear and impacts and/or improving penetration in the ground, such as teeth, supports or tooth bars (also referred to as adapters), and/or (front and side) guards, for example.

25 All these wear or protective elements and, particularly the teeth, are subjected to high mechanical stress, plastic deformations, and intense wear. For this reason, they usually have to be replaced with a certain frequency when the fracture thereof or the wear sustained so requires. Furthermore, these machines can work in a wide range of applications, in which it may be necessary to change the design of the teeth to improve performance of the bucket.

30

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 protective elements can be fixed mechanically (easier and faster to change) or welded (less expensive but hard to change and with the risk of damaging the blade with the weld), depending on the degree of abrasiveness of the ground and on the dimensions of the

5 machine. It must also be taken into account that large earth moving machines, particularly those operating in quarries and mines, are essential for production in said sites. To that end, the inactivity times of these machines may significantly affect productivity thereof, and it is of great interest that the wear elements can be changed quickly, safely, and on site, without having to take the machine or the bucket to a shop to use special equipment. To that end, it

10 is usually advantageous for the wear elements to be fixed mechanically and to use, to that end, a locking device, for example a pin.

Usually the wear element has a cavity in which a nose arranged in the support (for example, the adapter) on which the wear element will be assembled is housed. A through hole goes

15 through the nose, defining a housing, and at least one of the walls of the cavity has a hole such that, in an assembled position, the hole or holes in the walls of the cavity are superimposed on (i.e. , aligned or overlapping with) the housing and the locking device (which is substantially an elongated pin) can be introduced through the hole in the wall of the cavity until it is housed in the housing. In the assembled position, the locking device partially

20 projects from the housing and (at least partially) occupies the hole in the wall of the cavity.

The wear element is thereby locked in the assembled position. This superimposing (or alignment or overlapping) does not have to be complete, where partial superimposing is sufficient provided that 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

25 that has a cavity in which, in the assembled position, the nose is housed, but otherwise, the rest of the concept works in a similar fashion.

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

30

However, in certain cases it has been observed that locking devices of the state of the art present some drawbacks. Thus, for example, it would be desirable to have locking devices which can be housed completely inside the housing before positioning the wear element on

- the nose of the support, since this facilitates the assembly and disassembly of the locking device, particularly in those cases in which the wear elements are very close to one another. In other cases, the locking device (or the tip of the locking device which is in contact with the wear element) not being subjected to a force that pushes it against the wear element, i.e. ,

5 the locking device working independently of the wear element, is sought. Moreover, there is always a need to make locking devices in the most cost-effective and simplest manner possible.

10 Description of the Invention

The object of the invention is to overcome these drawbacks. This is achieved by means of a locking device of the type indicated above, characterized in that the locking device comprises:

15

- a locking element with a locking end and an internal end opposite the locking end,

- an internal element,

20 - movement means suitable for moving the locking element with respect to the internal element, in a reversible manner, between a retracted (or withdrawn) position and an extended (or deployed) position, where the movement between retracted position and the extended position defines a direction of movement, and

25 - elastic means which, in the extended position, exert a force in the direction of the direction of movement that tends to move the locking element closer to the internal element.

Preferably in the retracted position the locking element is completely within said housing and completely outside of said hole.

30 In the present invention, the wear element has a cavity in which a nose arranged in the support (for example, the adapter) on which the wear element will be assembled is housed. A hole in the nose defines a housing and one of the walls of the cavity (the one facing the open end of the housing) has another hole such that, in an assembled position, the hole in

- the wall of the cavity is superimposed on (i.e. , aligned or overlapping with) the housing and the locking device (which is substantially an elongated pin) can be introduced through the hole in the wall of the cavity until it is housed in the housing. Alternatively, the hole in the nose may be a through hole (so that the housing has two open ends), in which case there

5 may be two holes in both walls of the cavity facing the open ends of the housing.

In general, in the retracted position the locking element must be completely within the housing so that the wear element can be put over the nose of the support without being impeded by the locking element. In the retracted position the locking element is completely

10 outside the hole,

In the extended position part of the locking element (the corresponding locking end or at least part of the corresponding locking end) is outside the housing and is in the hole, so that it is able to be in contact with the wear element (in fact, it will be in contact as this contact will

15 precisely be the responsible of fixing the wear element to the support. The part of the locking element that goes into the hole is simultaneously going out of the housing, as the housing and the hole are mutually exclusive (I.e., none of them includes, comprises or surrounds the other).

20 Preferably in the extended position the locking end is blocking the wear element, while in the retracted position the locking element is out of the blockage of the wear element. In fact, the housing has a main axis that is parallel to the direction of movement, and the hole is after the open end of the housing. In order to put the wear element in the assembled position with the support, the wear element has to be moved in an assembling direction. This assembling

25 direction forms an angle greater than 60° with the direction of movement (preferably greater than 75° and more preferably greater than 85°). So, when the locking device is in the ex tended position, part of it (the locking end or, at least, part of the locking end) is in the hole and, therefore acts as a blockage against a possible movement of the wear element in the assembling direction. On the contrary, when the locking element is in the retracted position,

30 the locking device is completely out of the hole, i.e., it is out of the blockage of the wear element. So, the wear element can move freely in the assembling direction.

One of the additional advantages of the present invention is that its configuration facilitates

- disassembly, since the force of the elastic means facilitates the retraction (or withdrawing) of the locking device.

Another advantage of the present invention is in that the locking device is inside the housing

5 of the support, since the user thereby does not have to take the locking device out when changing the wear element, but rather can extract the wear element and put a new on in place without handling the locking device. That is particularly interesting since it is often not necessary to change the locking device (which can continue to be operative) when the wear element is changed, which allows achieving cost savings.

10

Preferably, the locking device comprises a capsule housing therein 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 housed in its entirety inside the capsule. It is likewise advantageous for the capsule to have a cross-section which, in at least one area, is

15 larger than the hole of the wear element. The capsule coming out of the housing of the support and not being able to pass through the hole is thereby prevented in the assembled position.

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

20

Preferably, the movement means comprise rotation means. The rotation means transform a rotation into a longitudinal movement.

Advantageously, the locking element is a cylindrical body with a base facing the internal

25 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 rotation 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

30 surfaces are superimposed on one another, and during a movement between the retracted position and the extended position the second inclined surface slides over the first inclined surface, causing the movement of the locking element with respect to the internal element. In other words, as a result of the inclined surfaces a rotational 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.

5 In the previous case, a preferred embodiment is one where the base of the internal element facing the locking element comprises a first seating surface arranged at the end of the first inclined surface which, in the extended position, is closer to the 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 closer

10 to the internal element, where in the extended position, both seating surfaces are superimposed on one another. The extended position is thereby rendered a stable position and the locking device does not tend to retract to retracted position due to the force exerted by the elastic means. It is particularly advantageous for one of the seating surfaces to comprise a first elevation at the end of the seating surface opposite the attachment area

15 between the seating surface and its corresponding inclined surface. This first elevation thereby defines an“end of stroke” and prevents the rotation from continuing beyond what is expected. Another particularly advantageous solution is when one of the seating surfaces comprises a second elevation at the end of the seating surface close to the attachment area between the seating surface and its corresponding inclined surface. This second elevation

20 prevents, for example due to the vibrations and impacts to which the wear element is subjected, the locking element and the internal element from rotating with respect to one another until the seating surfaces are no longer in contact with one another, with the subsequent risk that the locking device is retracted due to the force generated by the elastic means. The second elevation must be sized such that it prevents this involuntary rotation but

25 allows the voluntary rotation performed at will to retract the locking device.

Likewise in the previous case, another preferred embodiment is when the base of the internal element facing the locking element comprises a first guide surface opposite the first inclined surface and the base of the locking element facing the internal element comprises a second

30 guide surface opposite the second inclined surface, where, in the retracted position, the first guide surface and the second guide surface are superimposed on one another, and during a movement between retracted position and the extended position, the second guide surface slides along the first guide surface. In this case, when indicating that each guide surface is

- opposite its corresponding inclined surface, this means is that both surfaces have a spatial orientation in the same direction but in opposite senses. As will be seen below in the examples shown in the drawings, in some cases the inclined surface and its corresponding guide surface will be facing one another, whereas in other cases they will be on opposite

5 sides of a projection, i.e. ,“their backs” will be facing one another. With this orientation of the two guide surfaces (opposite the corresponding inclined surfaces), the force exerted by the elastic means tends to separate one guide surface from the other. This embodiment allows facilitating the retraction of the locking device, since the guide surfaces guide the locking element when it transitions from the extended position to retracted position. This embodiment

10 is compatible with the additional improvements indicated in the preceding paragraph.

Additionally, in the event that the embodiment includes a second elevation like the one indicated above, then another additional improvement is when the second elevation has a maximum elevation point having a maximum height, in the sense of the direction of movement, with respect to the seating surface, and the guide surface corresponding to the

15 inclined surface corresponding to the seating surface extends, in the direction of movement, beyond the maximum elevation point. The guide surface thereby performs its guiding function from the first instant of the retraction movement, which is when the second elevation is overcome.

20 Preferably, transitioning from retracted position to the extended position is achieved by means of a rotation of the locking element with respect to the internal element of 360° or less, preferably 180° or less, and very preferably 90°.

Advantageously, the rotation means comprise a hole arranged at the base of the locking

25 element opposite the internal element, where the hole is coaxial with the direction of movement and does not present cylindrical symmetry according to the direction of movement.

Preferably, the locking device comprises anti-rotation means suitable for preventing rotation

30 thereof with respect to the support. These anti-rotation means are advantageously arranged in the capsule.

Preferably, the locking device comprises air discharge means communicating the space

- comprised between the locking element and the internal element with the outside. In fact, in some cases the air remaining in this space is compressed when the locking device is retracted and generates an overpressure which hinders (and even prevents) retraction. The air discharge means allow the air trapped in this space to be discharged, preventing the

5 generation of overpressure in this space.

Advantageously, the locking device comprises an O-ring at an intermediate point of the side surface of the locking element. The purpose of this O-ring is to prevent, during operation of the earth moving machine, dirt and/or fines (fines are understood in the present description

10 as small-sized particles) from getting into the wear device. However, this O-ring may exacerbate the risk of the overpressure indicated above being generated. It is therefore particularly advantageous for the air discharge means to comprise an air discharge conduit extending between the space comprised between the locking element and the internal element and an upper end, where the upper end of the air discharge conduit is, according to

15 the direction of movement, below the O-ring when the locking element and the internal element are in the extended position, and is, according to the direction of movement, above the O-ring when the locking element and the internal element are in the retracted position. Therefore, when the locking device is extended, the upper end of the discharge conduit is “behind” the O-ring and the entry of dirt and/or fines into the locking element is prevented,

20 but, upon initiating retraction of the locking element, the upper end of the discharge conduit is located above the O-ring, such that the air can exit the space comprised between the locking element and the internal element and the generation of an overpressure hindering or preventing retraction of the locking device is prevented.

25 Preferably, the air discharge conduit is a cavity arranged between the outer side surface of the locking element and the side surface of said capsule.

A preferred embodiment of a locking device according to the invention is when the device comprises a rod with a first end fixed to the internal element and a second end housed inside

30 a cavity arranged in the locking element, where the second end is suitable for being moved according to the direction of movement along the cavity, where the cavity has an opening oriented towards the internal element and with the rod going through same, and where the elastic means are arranged between the second end of the rod and the opening. In this case,

- it is particularly advantageous for the first end of the rod to be fixed (and preferably screwed) to the internal element. It is also particularly advantageous for the locking element to have a mounting hole coaxial with the direction of movement and with a diameter greater than the maximum diameter of the rod such that the rod is suitable for being housed in the cavity

5 through the mounting hole. In fact, the rod preferably has a head at its end acting as a stop for the elastic means, where this head is what defines the maximum diameter of the rod. It is also advantageous for the device to comprise a plug closing the mounting hole to prevent dirt and stones from entering through the mounting hole.

10 Another preferred embodiment of a locking device according to the invention, equivalent to the preceding embodiment but“inverted”, is when the locking device comprises a rod with a first end fixed to the locking element and a second end housed inside a cavity arranged in the internal element, where the second end is suitable for being moved according to the direction of movement along the cavity, where the cavity has an opening oriented towards

15 the locking element and with the rod going through same, and where the elastic means are arranged between the second end of the rod and the opening. Like in the previous case, it is advantageous for the first end of the rod to be screwed to the locking element, for the internal element to have a mounting hole coaxial with the direction of movement and with a diameter greater than the maximum diameter of the rod such that the rod is suitable for being housed

20 in the cavity through the mounting hole, and for the device to comprise a plug closing the mounting hole.

In a further preferred embodiment of a locking device according to the invention is when the device comprises a capsule housing therein the internal element and at least the internal end

25 of the locking element and, additionally, the device comprises a rod with a first end fixed to the locking element and a second end housed inside a hollow space arranged in the capsule between the internal element and an inner end of the capsule opposed to an open end of the capsule, where the second end is suitable for being moved according to the direction of movement along the hollow space, where the internal element has a central opening

30 communicating the locking element with the hollow space and with the rod going through the central opening, and where the elastic means are arranged between the second end of the rod and the central opening.

- This last embodiment has some advantages:

- it allows to use stronger elastic means, in particular stronger springs, as they can have a greater outer diameter.

5 - it is easy to manufacture and to assemble.

- if the evacuation of the compressed air through the air discharge means, is not possible (or only partly possible), this embodiment offers two improvements: the stronger elastic means will compress further the air and the hollow space provides more room in which the air can be compressed (meaning a lower compression rate).

10 - the inner end of the capsule is closed, so that a welding step is avoided. In general, it is advantageous that the inner end is closed (directly i.e., the capsule having a base wall, or by welding the base of the internal element to the inner end of the capsule) in order to avoid that the earth particles and dust go into the mechanism of the locking device.

- it is possible to deliver to the user a single assembly (i.e., not a plurality of parts). This is

15 particularly interesting in the case when the device comprises two locking elements, with two movement means and two elastic means, as, with this preferred alternative, a locking device having only one capsule with all the remaining elements inside and fixed, can be assembled and delivered to the user.

20 In this last embodiment, preferably the first end of the rod is screwed to the locking element or, alternatively, it is fixed to the locking element through a hinged joint.

It can generally be considered that the elastic means have a length D in an unloaded state, measured in the sense of the direction of movement, and are suitable for being compressed

25 at most to a length T, measured in the sense of the direction of movement, and that the locking element and the internal element separate a distance E upon moving from the retracted position to the extended position, measured in the sense of said direction of movement. Advantageously, the difference between D and T is greater than or equal to E. It is thereby assured that the elastic means are not compressed above their allowable value.

30

In general, one advantage of the present invention is that the elastic means exert a force which helps to retract the locking device. This allows providing another advantageous solution which is achieved when the elastic means are in a partially compressed state when

- the locking element and the internal element are in the retracted position. It is thereby assured that the elastic means are exerting a force along the entire path between the deployed position and retracted position, which assures that the locking element reaches the retracted position completely (i.e., it prevents the risk of being slightly deployed, which may

5 occur if the elastic means stop exerting any force in the retracted position). Additionally, the elastic means preventing the locking device from moving out of its retracted position in an unwanted manner during the undesired handling thereof, is also achieved. 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 sense of said

10 direction of movement, then it is advantageous for the difference between P and T to be greater than or equal to E, to assure that the elastic means are not compressed above their allowable value.

Another advantageous embodiment of the invention is when the locking device comprises:

15

- a second locking element identical to the aforementioned locking element,

- second movement means identical to the aforementioned movement means and suitable for moving the second locking element with respect to the internal element, in a reversible

20 manner, between a retracted position and an extended position, where the movement between the retracted position and the extended position takes place in the same direction of movement indicated above,

- second elastic means identical to the elastic means indicated above which, in the extended

25 position, exert a force in the direction of the direction of movement that tends to move the second locking element closer to the internal element.

Essentially, this final embodiment consists of a locking device extending at both ends. It is common for the housing in the nose of the support to be a through hole and for the wear

30 element to have two holes, each of them located on opposite walls of the cavity. In these cases, the locking device is to be fitted in both holes, such that the wear element is locked at two points. This final embodiment allows achieving this objective.

- Brief Description of the Drawings

Other advantages and features of the invention will become apparent from the following 5 description, in which preferred embodiments of the invention are described in a non-limiting manner in reference to the attached drawings. In the drawings:

Figure 1 shows a perspective view of a wear element partially assembled on a support and an exploded view of a first embodiment of a locking device according to the invention.

10

Figures 2 to 5 show a perspective view and top, front, and side views, respectively, of the locking device of Figure 1 in the extended (or deployed) position.

Figures 6 and 7 show front and side views, respectively, of the locking device of Figures 2 to 15 5, without the capsule.

Figure 8 shows a view equivalent to Figure 6, but with the locking device in the retracted position.

20 Figure 9 shows a longitudinal section view, according to the direction of movement, of the locking device of Figure 8.

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

25

Figure 11 shows a perspective view of a support in which two locking elements according to the invention are introduced.

Figure 12 shows an exploded view of a second embodiment of a locking device according to 30 the invention.

Figure 13 shows a top view of the locking device of Figure 12.

- Figure 14 shows a longitudinal section view, according to the direction of movement, of the locking device of Figure 12 in the retracted position.

Figure 15 shows a longitudinal section view, according to the direction of movement, of the

5 locking device of Figure 12 in the extended position.

Figures 16-18 show details relating to an air discharge system according to the invention.

Figure 19 shows a perspective view of another embodiment of a locking device, without the

10 capsule.

Figure 20 shows a perspective view of the internal element of the locking device of Figure 19.

15 Figure 21 shows a side view of a further embodiment of a locking device, without the capsule.

Figure 22 shows an exploded view of the locking device of Figure 21.

Figures 23 and 24 show a longitudinal section view, according to the direction of movement,

20 of the locking device of Figure 21 , in a retracted position (Figure 23) and in an extended position (Figure 24).

Figure 25 shows an equivalent view to Figure 24 but of another embodiment of the locking device.

25

Figures 26 and 27 show a longitudinal section view of two possible capsules for the locking device of Figure 21.

30 Detailed Description of Embodiments of the Invention

Figures 1 to 10 show a first embodiment of a retaining device according to the invention. The device comprises a locking element 1 , an internal element 2, a rod 3, a spring 4, and a closing

- element 5. The locking element 1 has an O-ring 6 extending along its side perimeter. 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 projects from the capsule 7 (see Figures 2, 4, and 5).

5

The device is housed in a housing 9 provided in the nose of a support 10 (in Figure 1 , a weld on nose). Next, a wear element 1 1 (in Figure 1 , a tooth) is positioned over the support 10. The wear element 11 has a cavity suitable for housing therein the nose of the support 10 and has a hole 12 in one of the side walls of the cavity. In the assembled position, the hole 12 at

10 least partially overlaps the housing 9, such that the locking end 8 can project from the housing

9 and be housed in the hole 12, which causes the locking of the wear element 1 1 in the support 10.

The locking element 1 and the internal element 2 are substantially cylindrical bodies suitable

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

20 The internal element 2 is welded to the capsule 7 at the lower part of both elements (see

Figures 14 and 15), such that the internal element 2 is fixed to the capsule 7, whereas the locking element 1 can rotate with respect to the capsule 7. In turn, the capsule 7 has a side projection 14 which prevents the capsule 7 from being able to rotate with respect to the housing 9. This side projection 14 thereby defines anti-rotation means.

25

In this first embodiment, the movement means comprise rotation means. The rotation 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 surfaces 15 and 16 have a

30 helical configuration, such that they can slide with respect to one another upon rotation of the locking element 1 with respect to the internal element 2. Due to this helical configuration, the rotation also causes a movement in the direction of the axis of the helical surface, which is therefore the direction of movement. In fact, the internal element 2 has two first inclined

- surfaces 15 and the locking element 1 also has two second inclined surfaces 16, such that each first inclined surface 15 is paired with a second inclined surface 16.

At the end of each inclined surface 15 and 16 there is a seating surface 17 (the first seating

5 surface and the second seating surface, respectively). When the locking device is in its extended position (see Figures 6 and 7), the locking element 1 and the internal element 2 are supported on one another through their respective seating surfaces 17, which thereby define a stable locking position.

10 The seating surface 17 of the internal element 2 comprises a first elevation 18 at the end opposite the attachment area between the seating surface 17 and the first inclined surface 15. This first elevation 18 prevents the locking element 1 from being inadvertently rotated beyond this point, which would cause it to be abruptly retracted. The seating surface 17 of the internal element 2 also comprises a second elevation 19 at the end close to the

15 attachment area between the seating surface 17 and the first inclined surface 15. In this case, the purpose of this second elevation 19 is to prevent, due to the vibrations and shaking to which the locking device is subjected during use, the locking element 1 from being able to move from the stable position defined by the seating surfaces 17 and being retracted due to the force of the elastic means.

20

As can be seen, in this first embodiment the transition from the retracted to the deployed position (and vice versa) is achieved by means of a 90° rotation (a fourth of a turn). To perform this rotation, the base of the locking element 1 which is at the locking end 8, i.e. , the base opposite the internal element 2, has an hole 20 suitable for inserting a rotating tool.

25 This hole 20 has a shape with a substantially square cross-section.

The elastic means comprise a coil spring 4. The spring 4 is assembled around a rod 3. The rod 3 has a first end 21 fixed to the internal element 2 by means of a screw 13. The second end 23 of the rod 3 is housed inside a cavity 24 arranged in the locking element 1 and is

30 suitable for being moved according to the direction of movement along the cavity 24 when the locking device is extended or retracted. The second end 23 has a head 25 retaining the spring 4. The cavity 24 has an opening 26 oriented towards the internal element 2 and with the rod 3 going through same. The opening 26 has a smaller size than the spring 4, such

- that the spring 4 is retained between the head 25 and the opening 26. To facilitate the assembly of the ensemble, the opening 26 is in a closing element 5 which is screwed to the locking element 1. The closing element 5 has a larger diameter than the head 25, such that it is possible to introduce the head 25 and the spring 4 into the cavity 24 and then screw the

5 closing element 5 in the locking element 1.

In the present description and claims all the movements between the different elements of the device have been indicated in relative terms and merely for the purpose of explaining the operation of the device. Actually, the internal element 2 is fixed to the capsule 7 (for example,

10 by welding) and the capsule 7 is fitted in 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 1 1 is the locking element 1.

Figures 12 to 18 show a second embodiment of a locking device according to the invention.

15 The main difference between this second embodiment and the embodiment described above resides in the fixing of the rod 3 and the manner of assembling it in the device. In this case, the locking element 1 has a mounting hole 27 coaxial with the direction of movement and with a diameter greater than the maximum diameter of the rod 3 (i.e., the maximum diameter defined by the head 25). The rod 3 can therefore be housed in the cavity 24 by introducing it

20 through the mounting hole 27. The end of the rod 3 opposite the head 25 is threaded and goes through the opening 26 (which is smaller than the spring 4 in this case, since the spring 4 is also introduced in the cavity 24 through the mounting hole 27). This threaded end can be screwed to the internal element 2, such that the ensemble is assembled. A plug 28 closes the mounting hole 27.

25

In the two embodiments shown, the locking element is larger than the internal element and the cavity in which the head of the rod and the spring are housed is in the locking element. However, it would be possible to design a locking device in which the rod is fixed to the locking element and the internal element is large enough to house therein a cavity containing

30 the head of the rod and the spring, i.e., a configuration“symmetrical” to the one shown in the preceding examples.

The second embodiment of Figures 12 to 18 also includes air discharge means

- communicating the space comprised between the locking element 1 and the internal element 2 with the outside. However, these air discharge means may be included in a manner that is exactly identical in the first embodiment or the“symmetrical” embodiments indicated above.

5 The purpose of these air discharge means is to prevent the overpressure generated in the space comprised between the locking element 1 and the internal element 2 upon trying to retract the locking device. The O-ring 6 hinders the passage of air from this inner space to the outside. To prevent this overpressure, the locking device includes an air discharge conduit 29 extending between this inner space and an upper end 30 of the air discharge

10 conduit 29. The position of this upper end 30 is important. The purpose of the O-ring 6 is to prevent dirt and/or fines from getting into the locking device. Therefore, when the locking device is extended, it is important for the O-ring 6 to be able to perform its function, so the upper end 30 of the air discharge conduit 29 must be“below” the O-ring 6 (see Figure 15 and the enlarged detail of Figure 17). When the locking device is retracted, the upper end 30

15 of the air discharge conduit 29 must be“above” the O-ring 6, such that communication is established between the inner space and the outside which allows the exit of the air (see Figure 14 and the enlarged detail of Figure 16). The most advantageous aspect is that the upper end 30 of the air discharge conduit 29 is close to (below) the O-ring 6 when the locking device is extended, such that upon initiating retraction, the upper end 30 is quickly located

20 above the O-ring 6 and the overpressure generated in the inner space is as low as possible.

The air discharge conduit 29 has been formed from a cavity or gap between the outer side surface of the locking element 1 and the inner side surface of the capsule 7. Specifically, the inner side surface of the capsule 7 is not completely cylindrical, but rather has a segment

25 (the one corresponding to the air discharge conduit 29) that is oval-shaped or ellipsoidal (see

Figure 18, which schematically shows a cross-section of the locking element 1 and the capsule 7). Therefore, between both sides surfaces there is a gap that is sufficient for allowing the passage of air. In any case, this gap must large enough so as to assure that the O-ring 6 no longer applies a sealed closure.

30

Figures 19 and 20 show another embodiment of a locking device according to the invention. The same references have been used for those elements which are common with the preceding embodiments. In this new embodiment, the main difference resides in the fact that

- the base of the internal element 2 facing the locking element 1 comprises a first guide surface 31 opposite the first inclined surface 15 and the base of the locking element 1 facing the internal element 2 comprises a second guide surface 32 opposite the second inclined surface 16. In other words, the locking element 1 has a helical finger 33 which is suitable for being

5 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. In turn, the helical housing 34 defines the first inclined surface 15 and the first guide surface 31 , which are two opposing faces of the helical housing 34.

10

As can be seen in Figure 19, in the retracted position the first guide surface 31 and the second guide surface 32 are superimposed on one another. Upon rotation of the locking element 1 to take it to its extended position, the second guide surface 32 slides along the first guide surface 31.

15

The second elevation 19 generally has a maximum elevation point 35 (in the solution shown in the drawings it is an arris) having a maximum height, in the sense of the direction of movement, with respect to the seating surface 17. This maximum height is determined such that it is assured that the locking element 1 cannot“jump out” of the seating surface 17 onto

20 the first inclined surface 15, but it is low enough such that it can be overcome when taking the locking element 1 to its extended position. The first guide surface 31 (which corresponds to the first inclined surface 15 which, in turn, corresponds to the first seating surface 17) extends, in the direction of movement, beyond the maximum elevation point 35. It is thereby assured that when the locking element 1 is in its extended position and rotation starts to take

25 the locking element 1 to its retracted position, the two guide surfaces 31 and 32 immediately come into contact once the locking element 1 has overcome the maximum elevation point (35) of the second elevation 19.

Figure 11 shows an example in which two locking devices are used for fixing a wear element

30 to a support. However, it would also be possible to use one locking device which, while having a single internal element, has two locking elements extending on each side of the internal element, as discussed above.

- Figures 21 to 24 show another preferred embodiment of a locking device according to the invention. The same references have been used for those elements which are common with the preceding embodiments, although some of them are organized in a different way. The device comprises a locking element 1 , an internal element 2, a rod 3 and a spring 4. The

5 locking element 1 has an O-ring 6 extending along its side perimeter. 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 projects from the capsule 7 (see Figures 23 and 24). The internal element 2 is fixed to the capsule 7 through fixing means 41 (preferably a bolt) at an intermediate point of the capsule 7, so that between the bottom of the internal element 2 and

10 the inner end 37 of the capsule 7 there is a hollow space 36. As in previous embodiments, the capsule 7 has a side projection 14 which prevents the capsule 7 from being able to rotate with respect to the housing (9). The main difference between this embodiment and the previous ones resides in the fixing and positioning of the rod 3 and the spring 4. In this case, the rod 3 has the first end 21 that is threaded, and it is threaded to the locking element 1.

15 The second end 23 of the rod 3 is housed inside the hollow space 36 and is suitable for being moved according to the direction of movement along the hollow space 36 when the locking device is extended or retracted. The second end 23 has a head 25 retaining the spring 4. The internal element 2 has a central opening 39 communication the locking element 1 with the hollow space 36 and with the rod 3 going through this central opening 39. The central

20 opening 39 has a smaller size than the spring 4, such that the spring 4 is retained between the head 25 and the central opening 39.

Figure 25 shows a variant of this last embodiment in which the first end 21 of the rod 3 is not threaded to the locking element 1 but fixed to the locking element 1 through a hinged joint

25 (40).

Figure 26 shows one embodiment of locking device that is formed by two locking devices as shown in Figures 21 to 24 faced opposite to each other and with the inner end 37 of both capsules 7 welded together. Figure 27 is a variant of the locking device of Figure 26 in which,

30 instead of having two capsules 7 welded together, the device has only one capsule 7.

-