Locking assembly for a guard of a ground engaging tool

Abstract

A locking assembly (1) is used to releasably lock a shield (2) to a vehicle (3), wherein the locking assembly comprises a main body, a piston and a bolt, wherein the bolt is provided with a thread that engages with a corresponding thread of the piston and is used to control the position of the piston relative to the main body, wherein the locking assembly comprises a retaining device, wherein the retaining device comprises a plurality of balls, wherein the plurality of balls fix the bolt in a central recess of the main body.

Description

Technical Field

[0001] The present invention relates to the mechanical connection of wear parts to an underlying structure and was created with regard to connecting a ground engaging tool to a bucket of earth moving equipment, but a shield for protection against wear may also be attached to any type of vehicle. Background Art

[0002] Ground engaging tools (GET) for earth moving equipment (e.g., those used in mining operations) operate in a highly abrasive environment, are subject to high impact forces, and thus can wear or become damaged from use. As a result, GET (e.g., teeth on the front lip or edge of a bucket used in earth moving equipment) need to be replaced periodically.

[0003] Traditionally, the GET is welded to the lip of the bucket. When the GET reaches the end of its useful life, the GET can be cut from the bucket and a new GET welded in its place.

[0004] It should be understood that such cutting operations and re-welding operations are complicated, time-consuming and relatively expensive. In addition, these operations must usually be carried out in a workshop to ensure that the cutting and welding are correctly completed, which requires the bucket to be transported away from the earthmoving equipment.

[0005] Various mechanical attachment methods have been proposed in an attempt to alleviate these problems. Many methods involve the use of bolts and similar fastening devices that are inserted into the bucket lip. Generally, such devices have proven to be of limited use. Inserting bolts or the like into the bucket lip can result in undesirable stress concentrations in the lip, which can lead to cracking of the bucket lip. Even in situations where this can be avoided, the large forces to which the GET is subjected tend to deform the connecting bolts, making it difficult to subsequently extract the bolts using mechanical tools. In fact, in some cases, the deformation may be so severe that the GET must be cut away, completely eliminating any advantage of the mechanical connection.

[0006] In response to these problems, the applicant has designed a number of mechanical connection devices that overcome these problems. Examples of the applicant's devices are described in detail in U.S. Patent No. 7,219,454, U.S. Patent No. 7,472,503 and U.S. Patent Application No. 13 / 133,213 (also published as International PCT Publication WO20 0 / 065990), all of which are incorporated herein by reference.

[0007] These attachment arrangements involve the use of a shroud mounted around a lug or boss on the lip of an excavator bucket and a locking device located between the shroud and the boss, and involve applying an external compressive force to maintain the relative positions of the shroud, locking device and boss.

[0008] While these couplings have proven to be far less resistant to deformation than previous mechanical connectors, there are still cases where the couplings have one or more problems.

[0009] Sometimes, when using the GET, failure of the GET or the attachment may occur due to the applied load being higher than the device can withstand. The number of individual parts that form the attachment can result in a time-consuming assembly / reassembly of the GET. Sometimes, when it is necessary to remove the GET, the attachment is difficult to disassemble to release the GET from the bucket, or even if the attachment is released, the GET is not easily removed from the bucket lip, usually because of dirt and / or deformation of the attachment and / or GET that prevents removal.

[0010] In response to these challenges, the applicant has designed in WO2014037780A1 a locking assembly for releasably locking a shroud to a carrier, by which the removal and preferably the application of the GET to a carrier of earthmoving equipment is improved.

[0011] However, it has been found that the high forces and general abuse of the shield and carrier in use can sometimes deform or damage the connection / locking assembly, making removal of the shield difficult or impossible. Summary of the invention

[0012] It is therefore an object of the present invention to provide an improved locking assembly for releasably locking a shroud to a vehicle.

[0013] According to a first aspect, the object is achieved by a locking assembly as defined in the attached claim 1, having alternative embodiments defined in the dependent claims. Specifically, the locking assembly is used to releasably lock the shield to the vehicle and comprises a piston and a body, the body being provided with a through-central recess for receiving the piston so that the piston can move back and forth along the longitudinal axis of the recess, wherein the outer end of the piston extends outside the recess of the body. The locking assembly also includes a bolt, which is arranged in the central recess, wherein the bolt includes a handle and a gripping portion, which extends through a first end opening of the central recess so that the gripping portion can be reached from outside the body for rotating the bolt. In addition, at least a portion of the handle is provided with a thread that engages with a corresponding thread of the piston. The bolt is provided with a first bearing surface, which faces the corresponding second bearing surface of the body, wherein the first bearing surface and the second bearing surface are configured so that: when the bolt is rotated to force the piston out of the central recess, the first bearing surface of the bolt bears against the second bearing surface of the body, thereby preventing the bolt from moving in a first direction along the longitudinal axis. The locking assembly 1 also includes a retaining device, which is used to prevent the bolt from moving in a second direction opposite to the first direction. The retaining device is arranged in the central recess, wherein the outer surface of the retaining device faces the inner surface of the central recess. The outer surface of the retaining device is provided with a first recess, which extends at least partially around the periphery of the retaining device, wherein the inner surface of the central recess is provided with a second recess, which extends at least partially around the periphery of the inner surface of the body. The first recess and the second recess jointly define an intermediate space, which is used to receive a plurality of balls, which are distributed around the longitudinal axis so that the balls limit the movement of the retaining device relative to the body in the second direction. The retaining device is: a) integrated with the bolt, or b) provided as a separate component, which is positioned around the shank of the bolt and is suitable for limiting the movement of the bolt relative to the retaining device in the second direction.

[0014] The locking assembly is designed to Figure 1 and Figure 2The invention relates to a locking assembly of the present invention which is a kind of locking assembly of the present invention. The locking assembly of the present invention is a kind of ... Once the balls are in place within the intermediate space, the balls engage the body and the retaining means so that the bolt cannot be forced out of the central recess of the body without first removing the balls. The balls provide a very strong and durable connection that is strong enough to withstand the forces involved in pulling the piston back into the body when the locking assembly is disengaged. Furthermore, the greater forces required to force the shield onto the carrier are absorbed by the first bearing surface that engages the second bearing surface proximate the first end opening of the body. Thus, the locking assembly of the present invention is improved over prior art locking assemblies by providing a more robust design.

[0015] The first and second recesses may be shaped and positioned to allow a predetermined amount of axial movement of the balls along the longitudinal axis relative to the body and / or relative to the retaining device so that the balls are not axially loaded when the first bearing surface contacts the second bearing surface.

[0016] By thus providing a predetermined amount of axial play, the balls remain substantially axially unloaded so that when the shield is locked to the carrier, greater forces are absorbed by the first and second bearing surfaces when the piston is sent out of the body.

[0017] When constructed according to alternative b) above, the retaining device and bolt may be constructed to allow a predetermined axial play between the bolt and the retaining device when the first bearing surface contacts the second bearing surface. As described above, it may be desirable to keep the stress on the retaining device low so as not to damage the retaining device when the locking assembly is extended. Typically, the amount of stress that the first and second bearing surfaces can withstand is higher than the stress that the retaining device can withstand without deformation or damage. Therefore, another mechanism for ensuring that the main stress when the locking assembly is extended is to enable the retaining device to move relative to the bolt and ensure that there is axial play between the bolt 6 and the retaining device 12 when the first bearing surface 9 contacts the second bearing surface 10. After the balls are introduced into the intermediate recess as described above, the amount of axial relative movement between the retaining device and the body is controlled by any play around the balls. However, for the current construction where the retaining device is not integrated with the bolt but is provided as a separate component, the bolt is free to move away from the retaining device into the housing until the first bearing surface abuts the second bearing surface. From there, the bolt is free to move a predetermined distance outside the body again along the longitudinal axis of the body until some part of the bolt hits the retaining device. From there, mechanical interference between the retaining device and the bolt prevents the bolt from moving further outward, so that the bolt can still be used to pull the piston back into the body when the bolt is rotated.

[0018] The body or bolt is provided with a passage connecting the intermediate space to the outside of the locking assembly so that the plurality of balls can be moved into the intermediate space through the passage. The passage provides a means for the balls to enter the intermediate space while preferably also allowing the balls to be moved out of the intermediate space for disassembly, inspection and maintenance of the locking assembly.

[0019] The passage may be provided with closing means for closing the passage.

[0020] Providing such a closure arrangement ensures that the balls are retained in the intermediate space and prevents dust and dirt from entering the intermediate space, thereby increasing the reliability of the locking assembly.

[0021] The body and the piston may be provided with corresponding guide means configured to guide the piston for movement along the longitudinal axis and to prevent the piston from rotating together with the bolt.

[0022] Providing such a guide prevents the piston from rotating about the longitudinal axis, whereby rotation of the bolt may cause the threads to move the piston along the longitudinal axis. Thus, such a configuration enables the shield to be installed and removed without the use of special tools to prevent the piston from rotating.

[0023] The guiding device may comprise at least one protrusion arranged on the piston, the at least one protrusion extending radially outwardly from the piston, wherein the body is provided with at least one bearing surface or recess extending parallel to the longitudinal axis, wherein the bearing surface or recess is configured to guide the protrusion along the longitudinal axis and prevent the piston from rotating.

[0024] The projection and bearing surface together provide a simple means for preventing the piston from rotating about the longitudinal axis whilst allowing the piston to move back and forth along the longitudinal axis.

[0025] According to a second aspect, the object is also achieved by a shield system comprising a shield, a locking assembly as described above and a lug or boss which can be attached to a carrier to provide a means for engagement by a piston of the locking assembly so that the body moves relative to the lug or boss when the bolt is rotated. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A prior art shield and a corresponding prior art locking assembly for releasably locking the shield to a vehicle are shown.

[0027] Figure 2 Shows a prior art shield and also in Figure 1 , wherein the guard is positioned on the carrier.

[0028] Figure 3 A first embodiment of the novel locking assembly is shown in the form of a translucent component.

[0029] Figure 4 Shown with the same Figure 3 Shield and carrier for use with the locking assembly shown in FIG. The arrow indicates that the shield is forced onto the carrier.

[0030] Figures 5 to 7 Shown also in Figure 3 The locking assembly shown in Figure 4 The shield and carrier are shown in FIG. 1 at different stages of installation and removal of the shield to and from the carrier.

[0031] Figure 5 Insertion of the locking assembly into a corresponding opening of the shield is shown.

[0032] Figure 6 The bolt of the locking assembly is shown rotated to extend the locking assembly, thereby further urging the shield toward its installed use position onto the vehicle.

[0033] Figure 7 shows that by following along with Figure 6The shroud is disassembled by rotating the bolt in a direction opposite to that shown, wherein the body of the locking assembly abuts the exterior of the shroud to force the shroud off the vehicle.

[0034] Figure 8 The retaining device of the locking assembly is shown, wherein the body is shown in cross section to reveal the channel through which the ball has been introduced into the intermediate space of the retaining device, and wherein the closing device is shown in an exploded state as indicated by the arrow.

[0035] DETAILED DESCRIPTION

[0036] A locking assembly 1 according to a first embodiment will be described below with reference to the accompanying drawings.

[0037] For example Figure 3 and Figure 5 As shown, the locking assembly 1 is used with a shield and a carrier and is arranged in accordance with Figure 1 and Figure 2 The prior art locking assembly PA-110 shown works on the same principle.

[0038] The locking assembly 1 is used to releasably lock the shield 2 to the carrier 3. Figures 4 to 6 Mounting the shield to a vehicle using the locking assembly is shown in FIG.

[0039] The locking assembly 1 comprises a piston 4 and a body 5, wherein the body 5 is provided with a through central recess for receiving the piston 4 so that the piston 4 can move back and forth along the longitudinal axis 11 of the central recess, wherein the outer end of the piston 4 extends outside the central recess of the body 5. The locking assembly 1 also comprises a bolt 6, which is arranged in the central recess, wherein the bolt 6 comprises a handle and a gripping portion 7, wherein the gripping portion extends through a first end opening 8 of the central recess so that the gripping portion 7 can be accessed from outside the body 5 for rotating the bolt 6. At least a portion of the handle is provided with a thread that engages with a corresponding thread of the piston 4. In addition, the bolt 6 is provided with a first bearing surface 9, which faces a corresponding second bearing surface 10 of the body. The first bearing surface 9 and the second bearing surface 10 are configured such that: when the bolt 6 is rotated to force the piston 4 out of the central recess, the first bearing surface 9 of the bolt bears against the second bearing surface 10 of the body 5, thereby forcing the body to move in a first direction D1 along the longitudinal axis 11. The locking assembly 1 also comprises a retaining device 12 (see Figure 3 ), the retaining device is used to prevent the bolt 6 from moving in a second direction D2 opposite to the first direction D1 (see Figure 6) movement. The retaining device 12 is arranged in the central recess, wherein the outer surface of the retaining device faces the inner surface of the central recess. The outer surface of the retaining device 12 is provided with a first recess, which extends at least partially around the periphery of the retaining device 12, wherein the inner surface of the central recess is provided with a second recess, which extends at least partially around the periphery of the inner surface of the body 5, wherein the first recess and the second recess together define an intermediate space 13, which is used to receive a plurality of balls 14, which are distributed around the longitudinal axis so that these balls 14 limit the movement of the retaining device 12 relative to the body 5 along the second direction D2. In this embodiment, the retaining device 12 is arranged as a separate component positioned around the shank of the bolt 6 and is suitable for limiting the movement of the bolt 6 relative to the retaining device 12 along the second direction D2. However, in other embodiments, the retaining device 12 can alternatively be integrated with the bolt 6, for example attached to the bolt or formed integrally with the bolt.

[0040] The retaining device 12 and the bolt 6 are configured to allow a predetermined axial play between the bolt 6 and the retaining device 12 when the first bearing surface 9 contacts the second bearing surface 10. This play ensures that the retaining device 12 is not loaded when the locking assembly 1 forces the shield 2 onto the carrier 3 when the shield 2 is mounted to the carrier 3.

[0041] The body 5 or bolt is provided with a channel 15, which connects the intermediate space 13 to the outside of the locking assembly 1, so that the plurality of balls 14 can be moved into the intermediate space 13 through the channel 15 for assembling the locking assembly 1. After the balls 14 are inserted into the intermediate space, the channel 15 is provided with a closing device 28 for preventing the balls 14 from leaving the intermediate space 13 through the channel 15. The closing device 28 is Figure 7 15 is shown exploded from its installed position in the channel 15. In this embodiment, the closure device 28 is a metal plug that is welded in place. However, in other embodiments, other materials and means of providing an attached plug may be substituted. Furthermore, alternatively, the closure device 28 may not be welded in place, but may be removable so that the channel can be easily accessed to remove or lubricate the ball 14.

[0042] like Figure 3 and Figure 6As shown, the body 5 and the piston 4 are provided with corresponding guide means 16, 17, which are configured to guide the piston 4 to move along the longitudinal axis 11 and prevent the piston 4 from rotating relative to the body 5 about the longitudinal axis 11. The guide means include at least one protrusion 16 provided on the piston 4, which at least one protrusion extends radially outward from the piston 4. The body 5 is provided with left and right bearing surfaces 17, which are provided on corresponding left and right protrusions 19 and / or are provided by "overhanging" the body using the bearing surface 17. In other embodiments, one or more recesses may be provided instead of the protrusions, and the bearing surface 17 is provided inside the recess instead. Preferably, such a recess will extend parallel to the longitudinal axis 11, but the recess or protrusion 19 may also be slightly curved, as long as the piston is prevented from rotating together when the bolt 6 rotates and the longitudinal displacement is allowed. Therefore, the bearing surface 17 or recess is configured to guide the protrusion 16 along the longitudinal axis 11 and prevent the piston 4 from rotating.

[0043] Instead of providing a predetermined axial clearance between the retaining device 12 and the bolt 6, or in addition to providing the predetermined axial clearance, the first recess and the second recess can alternatively be shaped and positioned to allow the ball 14 to move axially by a predetermined amount along the longitudinal axis 11 relative to the body 5 and / or relative to the retaining device 12, so that the ball 14 is not axially loaded when the first bearing surface 9 contacts the second bearing surface 10.

[0044] In an embodiment according to the second aspect, a shield system is provided, wherein the shield system comprises the shield 2, the locking assembly 1 described above, and a lug or boss 18 which can be attached to a carrier 3 to provide a means for engagement of the piston 4 of the locking assembly 1 so that when the bolt 6 is rotated, the body 5 moves relative to the lug or boss 18. The lug or boss 18 is Figures 4 to 6 The lug or boss 18 has a central recessed portion for Figure 5 The insertion direction indicated by the large arrow in FIG. 1 receives the exterior of the piston 4 of the locking assembly 1. In addition, the lug or boss 18 and the exterior of the piston 4 are provided with corresponding matching protrusions and recesses, which are configured to engage when the locking assembly 1 is inserted along the insertion direction, thereby preventing relative displacement between the piston 4 and the lug or boss 18 along the longitudinal axis 11.

[0045] When the shield 2 is mounted on the carrier 3, the shield 2 is first mounted as Figure 4 As shown, the locking assembly 1 is moved onto the carrier 3. Once the central recess of the shield 2 is aligned with the lug or boss 18 provided on the carrier 3, the locking assembly 1 is Figure 5As shown, the piston 4 of the locking assembly 1 is inserted into the central recess of the shield 2. The outer portion of the piston 4 of the locking assembly 1 engages the lug or boss 18 when inserted. Figure 6 As shown, the locking assembly 1 is then expanded by rotation of its bolt 6. As the locking assembly 1 expands / extends, the locking assembly 1 pushes the lugs or bosses 18 and the shield 2 apart to force the shield 2 further onto the carrier 3, thereby bringing the shield 2 into its final use position. The shield 2 rests against the carrier 3 in the fixed use position. Furthermore, the locking assembly 1 uses its first bearing surface 9 and second bearing surface 10 to transfer forces from the bolt 6 to the shield 2, thereby providing a very strong and durable design capable of withstanding the high stresses involved when using the carrier 3. It will be appreciated that the retaining device 12 will most likely not be able to withstand forces as high as those involved when using the carrier 3, and therefore the design provides for the retaining device 12 to be substantially unloaded in use, thereby preventing damage to the retaining device 12.

[0046] Sometimes it is necessary to remove the shroud 2 for replacement or repair. Loosening the lock assembly 1 by merely shortening the length of the lock assembly 1 by rotation of the bolt 6 of the lock assembly 1 will not release the shroud 2, which is typically held in place by considerable friction. One advantage of the lock assembly 1 of the present invention is that it can be used to force the shroud 2 out of the vehicle 3. The exterior of the piston 6 engages the lug or boss 18, and the retaining device 12 holds the bolt 6 within the body 5 as the bolt 6 is rotated. This enables the lock assembly 1 to force the body 5 toward the lip of the vehicle 3 until the body 5 is eventually released as Figure 7 It should be noted that the rotation direction of the bolt 6 is the same as that of the bolt 6. Figure 6 The direction of rotation shown is opposite. Furthermore, it should be noted that the bolt 6 now transmits force to the body 5 via the retaining means 12 rather than via the first and second bearing surfaces 9, 10. Prior art locking assemblies that do not have the retaining means 12 of the present invention sometimes fail due to the high forces involved in trying to force the shield off the vehicle. The present locking assembly 1 has a very strong and durable retaining means 12 that is able to withstand greater forces than prior art locking assemblies, thereby reducing the risk of failure when removing the shield from the vehicle.

[0047] A plastic, rubber or elastomeric cover may be fitted to the shroud to protect the locking assembly. Providing such a cover reduces the risk of foreign particles such as dust and dirt entering the locking assembly 1 and also protects the gripping portion of the bolt 6 from external abuse. Overall, this increases the life of the locking assembly 1 while still being easy to remove so that the gripping portion can be operated to remove the shroud 2 from the carrier 3.

Claims

1. A locking assembly (1) for releasably locking a shield (2) to a carrier (3), in, The locking assembly (1) comprises: Piston (4), A body (5) provided with a through central recess for receiving the piston (4) so ​​that the piston (4) can move back and forth along the longitudinal axis (11) of the recess, wherein the outer end of the piston (4) extends beyond the central recess of the body (5), The locking assembly (1) further comprises a bolt (6) disposed in the central recess, wherein the bolt (6) comprises a handle and a gripping portion (7), the gripping portion extending through a first end opening (8) of the central recess such that the gripping portion (7) is accessible from outside the body (5) for rotating the bolt (6), wherein at least a portion of the handle is provided with a thread that engages with a corresponding thread of the piston (4), The bolt (6) is provided with a first bearing surface (9), the first bearing surface facing the corresponding second bearing surface (10) of the main body, wherein the first bearing surface (9) and the second bearing surface (10) are configured such that: when the bolt (6) rotates to force the piston (4) to disengage from the central recess, the first bearing surface (9) of the bolt bears against the second bearing surface (10) of the main body (5), thereby preventing the bolt (6) from moving in the first direction (D1) along the longitudinal axis (11), The locking assembly (1) further comprises a retaining device (12), the retaining device being used to prevent the bolt (6) from moving in a second direction (D2) opposite to the first direction (D1). wherein the retaining device (12) is arranged in the central recess, wherein the outer surface of the retaining device faces the inner surface of the central recess, wherein the outer surface of the retaining device (12) is provided with a first recess, the first recess at least partially extending around the periphery of the retaining device (12), wherein the inner surface of the central recess is provided with a second recess, the second recess at least partially extending around the periphery of the inner surface of the main body (5), wherein the first recess and the second recess jointly define an intermediate space (13), the intermediate space being used to receive a plurality of balls (14), the plurality of balls being distributed around the longitudinal axis so that the balls (14) limit the movement of the retaining device (12) relative to the main body (5) along the second direction (D2); and Wherein, the retaining device (12) a) integrated with the bolt (6), or b) is provided as a separate component, which is positioned around the shank of the bolt (6) and is suitable for limiting the movement of the bolt (6) relative to the retaining device (12) in the second direction (D2).

2. The locking assembly (1) according to claim 1, wherein: The first recess and the second recess are shaped and positioned to allow a predetermined amount of axial movement of the ball along the longitudinal axis (11) relative to the body (5) and / or relative to the retaining device (12), so that when the first bearing surface (9) contacts the second bearing surface (10), the ball (14) is not axially loaded.

3. The locking assembly (1) according to claim 1 or 2 according to alternative b) of claim 1, wherein: The retaining device (12) and the bolt (6) are configured to allow a predetermined axial play between the bolt (6) and the retaining device (12) when the first bearing surface (9) contacts the second bearing surface (10).

4. The locking assembly (1) according to claim 1 or 2, wherein: The body (5) or the bolt is provided with a channel (15) which connects the intermediate space (13) to the outside of the locking assembly (1) so that the plurality of balls (14) can move into the intermediate space (13) through the channel.

5. The locking assembly (1) according to claim 4, wherein: The passage (15) is provided with a closing device (28) for closing the passage (15).

6. The locking assembly (1) according to claim 1 or 2, wherein: The body (5) and the piston (4) are provided with corresponding guide means configured such that the piston (4) is guided to move along the longitudinal axis (11) and such that the piston is prevented from rotating together with the bolt (6).

7. The locking assembly (1) according to claim 6, wherein: The guiding means comprises at least one projection (16) arranged on the piston (4), the at least one projection extending radially outwards from the piston (4), wherein the body (5) is provided with at least one bearing surface (17) or recess extending parallel to the longitudinal axis (11), wherein the bearing surface (17) or recess is configured to guide the projection (16) along the longitudinal axis (11) and prevent the piston (4) from rotating.

8. A shield system for a vehicle, wherein: The shield system comprises a shield, a locking assembly according to any one of claims 1 to 7 and a lug or boss (18) which can be attached to the carrier to provide a means for engaging the piston of the locking assembly (1) so that when the bolt (6) is rotated, the body (5) moves relative to the lug or boss (18).

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