EA043567B1 - FIXING UNIT FOR GRIP TOOL HOUSING - Google Patents

Description

Field of technology

The invention relates to the mechanical connection of wear parts to internal structures and is designed to connect soil gripping tools to earthmoving equipment buckets, but can be used to attach a wear guard to any type of load-bearing accessory.

State of the art

GET-ground engaging tools for earthmoving equipment, such as those used in the mining industry, operate in highly abrasive environments, are subject to high impact loads and thus wear out or become damaged during use. Soil gripping tools, such as the teeth used on the leading edge or bucket edges of earthmoving equipment, therefore require regular replacement.

Typically, soil gripping tools are welded to the edges of buckets. When these tools reach the end of their life, they can be cut off the bucket and new grappling tools can be welded in their place.

It should be understood that such cutting and rewelding operations are complex, time consuming and relatively expensive. Additionally, they typically must be done in a workshop to ensure proper cutting and welding, requiring the bucket to be transported separately from the digging equipment.

In an attempt to solve these problems, various mechanical attachment methods have been proposed. Many of these methods involve the use of bolts and similar fasteners inserted into the lip of the bucket. In general, such means turned out to be of little use. Inserting a bolt or similar element into the lip of a bucket can cause undesirable stress concentration within the lip, resulting in cracking of the bucket lip. Even if this can be avoided, the high forces that the soil gripping tools are subjected to tend to deform the connecting bolts, making their subsequent removal with power tools difficult. Indeed, in some cases the deformation may be so severe that said instruments must be cut out, completely eliminating all the benefits of a mechanical connection.

In response to these problems, the applicant has developed a number of mechanical coupling means that overcome these problems. Examples of Applicant's devices are described in detail in US Patent Nos. 7,219,454 and 7,472,503 and US Patent Application No. 13/133,213 (also published as PCT International Publication WO 20 0/065990), the contents of which are incorporated herein by reference.

These connecting means involve the use of a housing that is attached to a lip or stop on the edge of the excavator bucket, a locking means that is located between the housing and the stop, and the application of an external compressive force to maintain the relative position of the housing, the locking device and the stop.

Although these coupling means have proven to be much less susceptible to deformation than known mechanical connectors, these coupling means have nevertheless been known to have one or more problems.

Occasionally, when using soil gripping tools, it is possible for said tools or connecting means to break due to the applied load being greater than the load they can withstand. The number of individual components forming the connecting means can make installation/reinstallation of said tools labor intensive. In other cases where it is necessary to remove said tools, the coupling means is difficult to disengage to release the tool from the bucket, or, even if the coupling means is disconnected, the soil gripping tool is not easily removed from the edge of the bucket, usually due to contamination and/or deformation of the coupling means and /or a tool that prevents removal.

In response to these problems, the applicant has developed a locking assembly for releasably securing the housing to a holder, which is described in the international publication WO 2014037780 A1 and which improves the ability to remove and preferentially install soil gripping tools on an earthmoving equipment holder.

However, it has been found that the greater force and general handling of the housing and holder during operation sometimes results in deformation or damage to the connecting means/locking assembly such that detachment of the housing becomes difficult or impossible.

The essence of the invention

It is therefore an object of the invention to provide an improved locking assembly for releasably securing a housing to a holder.

According to the first aspect, this goal is achieved using a locking unit according to claim 1 of the attached claims with alternative embodiments described in the dependent claims. In particular, the fixing unit is designed for detachable fixation of the casing on the holder and contains a piston and a main body having a through central cavity for housing the piston so that the piston can move back and forth

- 1 043567 along the longitudinal axis of the cavity, with the outer end portion of the piston extending outward from the cavity of the main body. The locking assembly also includes a bolt located inside the central cavity, the bolt including a rod and a gripping portion extending through the first end hole of the central cavity such that the gripping portion is accessible from the outside of the main body for rotating the bolt. In addition, at least a portion of the rod has threads configured to engage with a corresponding thread of the piston. The bolt has a first load-bearing surface facing a corresponding second load-bearing surface of the main body, wherein said first and second load-bearing surfaces are configured such that when the bolt is rotated to push the piston out of the central cavity, said first load-bearing surface of the bolt abuts said second load-bearing surface of the main body, such that thus preventing the bolt from moving in a first direction along the longitudinal axis. The locking unit 1 also includes retaining means for preventing the bolt from moving in a second direction opposite to the first direction. The holding means is located in the central cavity, with its outer surface facing the inner surface of the central cavity. The outer surface of the holding means has a first recess extending at least partially around the circumference of the holding means, and the inner surface of the central cavity has a second recess extending at least partially around the circumference of the inner surface of the main body. Said first and second recesses together define an intermediate space for receiving balls distributed around a longitudinal axis such that the balls limit movement of the holding means in said second direction relative to the main body. The retaining means are either a) built into the bolt, or b) formed as a separate part located around the bolt shank and configured to limit movement of the bolt relative to the retaining means in said second direction.

The locking assembly is configured to operate on the same principles as the PA-110/PA-30 locking assembly known in the prior art, shown in FIG. 1 and 2 and described in international publication WO 2014037780 A1. In particular, the locking assembly is used to mechanically secure the housing to the holder after the holder is positioned on the edge of the holder. To ensure fixation, the fixing unit is installed in a predetermined position, respectively, between the parts of the casing and the holder. Once positioned correctly, the length of the locking assembly is increased by turning the bolt, which allows the piston to move further away from the main body of the locking assembly. With a further increase in the length of the fixing unit, the said unit moves the corresponding parts of the casing and holder apart so that the casing is pressed more tightly against the holder and cannot be moved from it. A special feature of the claimed locking assembly is the way the bolt is secured inside the main body. When assembling the fixing unit, 1 bolt is inserted into the central cavity of the main body, after which the balls are moved into the intermediate space between the main body and the retaining means. When the balls are in the intermediate space, they provide engagement of the main body with the retaining means so that the bolt cannot be moved from the central cavity of the main body without first removing the balls. The balls provide a very strong connection, strong enough to withstand the forces of pushing the piston back into the main body when the locking assembly is released. In addition, the large forces required to press the housing against the holder are absorbed by said first support surface engaging said second support surface adjacent to said first end opening of the main body. Thus, this locking unit is improved compared to locking units of the prior art due to a more reliable design.

Said first and second recesses may be shaped and positioned to permit the balls to move a predetermined amount axially along a longitudinal axis relative to the main body and/or the holding means, such that the balls do not experience an axial load when said first bearing surface comes into contact with said first bearing surface. second bearing surface.

Thus, by providing a predetermined amount of axial clearance, the balls remain substantially unloaded in the axial direction, so that when the piston moves from the main body while fixing the casing on the holder, large forces are absorbed by said first and second bearing surfaces.

When configured according to option b) above, the retaining means and the bolt may be configured to provide a predetermined axial clearance between the bolt and the retaining means when said first load-bearing surface comes into contact with said second load-bearing surface. As stated above, it may be necessary to maintain a slight load on the retaining means to prevent damage to the retaining means when the locking assembly is pulled out. Typically, the amount of load that said first and second load-bearing surfaces can withstand is greater than the load that the holding means can withstand without deformation or damage. Thus, another mechanism for ensuring that the main stresses are retained when the locking assembly is extended from the holding means is to ensure

- 2 043567 holding means movable relative to the bolt and providing axial clearance between the bolt 6 and holding means 12 when the first bearing surface 9 is in contact with the second bearing surface 10. After inserting the balls into the intermediate recess as described above, the amount of axial relative movement between retaining means and the main body is determined by any gap around the balls. However, in the current configuration, in which the retaining means is not built into the bolt, but is formed as a separate part, the bolt is free to move away from the retaining means into the body until said first load-bearing surface abuts said second load-bearing surface. surface. The bolt is then free to move again a predetermined distance outward from the main body along the longitudinal axis of the main body until some portion of the bolt is caught in the retaining means. The mechanical interaction between the retaining means and the bolt then prevents further outward movement of the bolt so that the bolt can still be used to push the piston back into the main body when the bolt is turned.

The main body or bolt has a passage connecting the intermediate space to the outside of the locking assembly so that the balls can move into the intermediate space through the passage. The passage allows the balls to move into the intermediate space and preferably also allows the balls to move out of the intermediate space for disassembly, inspection and servicing of the locking assembly.

The passage may be equipped with a closing means for closing the passage.

The presence of such a closing means allows the balls to be retained in the intermediate space and prevents dust and dirt from entering the intermediate space, thereby increasing the reliability of the locking assembly.

The main body and the piston may include corresponding guiding means configured to allow the piston to be guided to move along the longitudinal axis so that the piston and bolt are prevented from rotating together.

The presence of such a guide means prevents the piston from rotating around the longitudinal axis and thus allows the bolt to be rotated so that the thread allows the piston to move along the longitudinal axis. Thus, this configuration allows installation and removal of the housing without the use of special tools to prevent rotation of the piston.

The guide means may have at least one protrusion formed on the piston and extending radially outward from the piston, the main body having at least one support surface or recess extending parallel to the longitudinal axis, the support surface or recess configured to guide the protrusion along longitudinal axis and preventing piston rotation.

The protrusion and the support surface together provide a simple means for preventing rotation of the piston about the longitudinal axis, allowing the piston to move back and forth along the longitudinal axis.

According to a second aspect, this object is also achieved by a housing assembly comprising a housing, a locking assembly described above, and a projection or stop attached to a holder to provide a means for engaging a piston of the locking assembly so that the main body can be moved relative to the projection or stop when turning the bolt.

Brief description of drawings

On the drawings:

fig. 1 shows a prior art housing and a corresponding prior art locking assembly for releasably securing the housing to a holder;

fig. 2 shows the prior art housing and locking assembly also shown in FIG. 1, with the casing located on the holder;

fig. 3 shows a first embodiment of the new locking assembly, with some parts shown translucent;

fig. 4 shows a housing and holder for use with the locking assembly also shown in FIG. 3, with the arrow indicating how the casing moves onto the holder;

fig. 5-7 show the locking assembly also shown in FIG. 3, together with the housing and holder also shown in FIG. 4, at different stages of installation and dismantling of the casing on the holder;

fig. 5 shows the insertion of the locking assembly into the corresponding hole of the casing;

fig. 6 depicts turning the bolt of the locking assembly to expand it to allow the housing to move further onto the holder to the installation position of use;

fig. 7 shows the removal of the casing by turning the bolt in the opposite direction to that shown in FIG. 6, wherein the main body of the fixing assembly is adjacent to the outer part of the casing, allowing it to move from the holder;

fig. 8 shows the holding means of the locking assembly, the main body being shown in cross-section to show the passage through which the balls were introduced into the intermediate space of the holding means, and the closing means being shown in an open state as

- 3 043567 is shown by arrows.

1 fixing knot 12 retaining agent 2 casing 13 intermediate space 3 holder 14 balloons 4 piston 15 passage 5 main building 16 guide protrusion 6 bolt 17 guide bearing surface facilities 7 gripping part 18 protrusion or stop 8 first end hole 19 protruding part of the main body 9 first bearing surface D1 first direction 10 second bearing surface D2 second direction AND longitudinal axis ONCE known level locking assembly technology EARLY locking assembly of the prior art - disassembled

Detailed description

The fixing unit 1 according to the first embodiment will now be described with reference to the accompanying drawings.

As shown, for example, in FIG. 3 and 5, the locking assembly 1 is designed for use with a housing and holder and operates on the same principle as the prior art PA-110 locking assembly shown in FIG. 1 and 2.

The fixing unit 1 is designed for detachable fixation of the casing 2 on the holder 3. Installation of the casing on the holder using the fixing unit is shown in Fig. 4-6.

The fixing unit 1 contains a piston 4 and a main body 5 having a through central cavity for housing the piston 4 so that the piston 4 can be moved back and forth along the longitudinal axis 11 of the central cavity, and the outer end portion of the piston 4 extends outward from the central cavity of the main body 5. The fixing unit 1 also includes a bolt 6 located in the central cavity, the bolt 6 comprising a rod and a gripping portion 7 extending through the first end hole 8 of the central cavity so that the gripping portion 7 is accessible from the outside of the main body 5 for rotating the bolt 6. at least a portion of the rod has a thread configured to engage with a corresponding thread of the piston 4. In addition, the bolt 6 has a first bearing surface 9 facing a corresponding second bearing surface 10 of the main body. The first 9 and second 10 bearing surfaces are designed so that when the bolt 6 is rotated to advance the piston 4 from the central cavity, the first bearing surface 9 of the bolt abuts the second bearing surface 10 of the main body 5, thus ensuring movement of the main body in the first direction D1 along the longitudinal axis 11. The locking unit 1 also includes a holding means 12 (see FIG. 3) to prevent the bolt 6 from moving in a second direction D2 (see FIG. 6) opposite to the first direction D1. The holding means 12 is located in the central cavity, with the outer surface of the holding means facing the inner surface of the central cavity. An outer surface of the holding means 12 has a first recess extending at least partially around the circumference of the holding means 12, the inner surface of the central cavity having a second recess extending at least partially around the circumference of the inner surface of the main body 5, said first and second recesses being together. define an intermediate space 13 to accommodate balls 14 distributed around a longitudinal axis such that the balls 14 limit the movement of the holding means 12 in a second direction D2 relative to the main body 5. In this embodiment, the holding means 12 is formed as a separate part located around the bolt shaft 6 with the possibility of limiting the movement of the bolt 6 relative to the holding means 12 in the second direction D2. However, in other embodiments, the holding means 12 may be integrated

- 4 043567 in bolt 6, for example attached to the bolt or formed as one piece with it.

The retaining means 12 and the bolt 6 can be designed to provide a predetermined axial clearance between the bolt 6 and the retaining means 12 when the first load-bearing surface 9 comes into contact with the second load-bearing surface 10. Thanks to the gap, the retaining means 12 is not subject to load when the fixing unit 1 presses the casing 2 to holder 3 when installing casing 2 on holder 3.

The main body 5 or bolt has a passage 15 connecting the intermediate space 13 with the outside of the locking unit 1 so that the balls 14 can be moved into the intermediate space 13 through the passage 15 to assemble the locking unit 1. After the balls 14 have been placed in the intermediate space, the passage 15 is provided with a closing means 18 to prevent the balls 14 from leaving the intermediate space 13 through the passage 15. The closing means 18 is shown in FIG. 7 removed from its mounting position in the passage 15. In this embodiment, the closure means 18 is a metal plug that is welded in place. However, in other embodiments, other materials and means for securing the plug may be provided. In addition, the cover means 18, instead of being welded in place, may alternatively be removable to provide easy access to the passage for removing or lubricating the balls 14.

As shown in FIG. 3 and 6p, the main body 5 and the piston 4 are equipped with corresponding guide means 16, 17, which are configured to guide the piston 4 to move along the longitudinal axis 11 so that rotation of the piston 4 around the longitudinal axis 11 relative to the main body 5 is prevented. at least one protrusion 16 formed on the piston 4 and extending radially outward from the piston 4. The main body 5 has left and right support surfaces 17 located on the corresponding left and right protruding parts 19 and/or by overhanging the main body enclosing the support surfaces 17. In other embodiments, one or more recesses may be provided in place of the protrusions, instead providing support surface(s) 17 within the recesses. Preferably, such recesses extend parallel to the longitudinal axis 11, although the recesses or protrusions 19 may be slightly curved, provided that co-rotation of the piston is prevented when turning the bolt 6 and longitudinal movement is ensured. Thus, the supporting surface 17 or recess is configured to guide the protrusion 16 along the longitudinal axis 11 and prevent rotation of the piston 4.

Instead of, or in addition to, providing a predetermined axial clearance between the retaining means 12 and the bolt 6, said first and second recesses may alternatively be shaped and positioned to provide a predetermined amount of axial movement of the balls 14 along the longitudinal axis 11 relative to the main body 5 and/or relative to the holding means 12, so that the balls 14 do not experience an axial load when the first bearing surface 9 comes into contact with the second bearing surface 10.

In an embodiment according to the second aspect, a housing assembly is provided that includes a housing 2, the locking unit 1 described above, and a projection or stop 18 configured to be attached to the holder 3 to provide a means for attaching the piston 4 of the locking unit 1 so that when the bolt 6 is rotated the main body 5 is allowed to move relative to the protrusion or stop 18. The protrusion or stop 18 is shown in cross section in FIG. 4-6. The protrusion or stop 18 has a central recessed portion for positioning the outer portion of the piston 4 of the locking assembly 1 in the insertion direction shown by the large arrow in FIG. 5. In addition, the protrusion or stop 18 and the outer part of the piston 4 have corresponding mating protrusions and recesses configured to connect when inserting the locking unit 1 along the direction of insertion and subsequently prevent relative movement between the piston 4 and the protrusion or stop 18 along the longitudinal axis 11 .

When installing the casing 2 on the holder 3, the casing 2 is first moved onto the holder 3, as shown in FIG. 4. When the central cavity of the casing 2 is aligned with the protrusion or stop 18 provided on the holder 3, the locking unit 1 is inserted into the central cavity of the casing 2, as shown in FIG. 5. The outer part of the piston 4 of the fixing unit 1 is connected to the protrusion or stop 18 upon insertion. The fixing unit 1 is subsequently expanded by turning its bolt 6, as shown in FIG. 6. As the locking assembly 1 expands/extends, it pushes out the projection or stop 18 and the housing 2 to allow the housing 2 to be pressed further against the holder 3 to bring the housing 2 into its final position for use. The housing 2 is adjacent to the holder 3 in a fixed position for use. In addition, the first and second load-bearing surfaces 9, 10 of the retaining unit 1 provide force transmission from the bolt 6 to the housing 2 and thus provide a very robust structure that can withstand heavy loads encountered when using the holder 3. It should be understood that the retaining the means 12 likely cannot withstand such large forces as those encountered when using the holder 3, so this design provides significant relief to the holding means 12 during operation, thereby preventing damage to the holding means 12.

- 5 043567

Sometimes it is necessary to remove housing 2 for replacement or maintenance. Simply loosening the fixing unit 1 by reducing its length by turning the bolt 6 will not lead to the detachment of the casing 2, which is usually held in place due to significant friction forces. An advantage of this locking assembly 1 is that it can be used to force release the housing 2 from the holder 3. The outer portion of the piston 6 engages the projection or stop 18, and the retaining means 12 holds the bolt 6 inside the main body 5 when the bolt 6 is rotated. makes it possible to press the main body 5 against the edge of the holder 3 using the fixing unit 1 until the main body 5 pushes the casing 2 out, as shown in FIG. 7. It should be noted that the bolt 6 is rotated in the opposite direction to the direction of rotation shown in FIG. 6. It should also be noted that the bolt 6 now transmits force to the main body 5 through the retaining means 12, rather than through the first and second load-bearing surfaces 9, 10. Prior art locking assemblies that do not have such retaining means 12 sometimes come out of malfunctioning due to the large forces encountered when trying to remove the casing from the holder. This locking assembly 1 has a very strong holding means 12 that can withstand greater forces than prior art locking assemblies, thus reducing the risk of breakage when removing the housing from the holder.

To protect the locking assembly, plastic, rubber or elastomeric covers can be installed on the housing. Thanks to such covers, the risk of foreign particles, such as dust and dirt, getting into the fixing unit 1 is reduced, and the gripping part of the bolt 6 is also protected from external influences. Overall, this increases the service life of the locking unit 1 while allowing for easy removal so that the gripping part can be used to separate the housing 2 from the holder 3.

Claims (8)

CLAIM 1. Fixing unit (1) for detachable fixation of the casing (2) on the holder (3), containing: a piston (4), a main body (5), having a through central cavity to accommodate the piston (4) allowing the piston (4) to move ) back and forth along the longitudinal axis (11) of the cavity, and the outer end part of the piston (4) extends outward from the central cavity of the main body (5), while the locking unit (1) also contains a bolt (6) located inside the central cavity, wherein the bolt (6) has a rod and a gripping portion (7) extending through the first end hole (8) of the central cavity so that the gripping portion (7) is accessible from outside the main body (5) to allow rotation of the bolt (6), wherein at least a portion of the rod has a thread configured to engage with a corresponding thread of the piston (4), wherein the bolt (6) has a first bearing surface (9) facing a corresponding second bearing surface (10) of the main body, and said first ( 9) and the second (10) bearing surfaces are designed so that when the bolt (6) is rotated to push the piston (4) out of the central cavity, said first bearing surface (9) of the bolt abuts against said second bearing surface (10) of the main body, thus , preventing movement of the bolt (6) in a first direction (D1) along the longitudinal axis (11), while the locking unit (1) also contains retaining means (12) for preventing movement of the bolt (6) in a second direction (D2), opposite to the specified in a first direction (D1), wherein the holding means (12) is located in the central cavity, and its outer surface faces the inner surface of the central cavity, and the outer surface of the holding means (12) has a first recess extending at least partially around the circumference of the holding means (12), and the inner surface of the central cavity has a second recess extending at least partially around the circumference of the inner surface of the main body (5), and said first and second recesses together define an intermediate space (13) for receiving balls (14) distributed around longitudinal axis, so that the balls (14) limit the movement of the holding means (12) in the specified second direction (D2) relative to the main body (5), while the holding means (12) is made a) integral with the bolt (6) or b) in the form of a separate part located around the shaft of the bolt (6), and is configured to limit the movement of the bolt (6) relative to the holding means (12) in the specified second direction (D2). 2. Fixing unit (1) according to claim 1, in which said first and second recesses have such a shape and are so located that it is possible to axially move the balls (14) at a given distance along the longitudinal axis (11) relative to the main body (5) and/or relative to the holding means (12), so that the balls (14) do not experience an axial load when said first non- - 6 043567 the bearing surface (9) is in contact with the specified second bearing surface (10). 3. The fixing unit (1) according to any of the previous paragraphs, dependent on claim 1, subject to alternative b), in which the retaining means (12) and the bolt (6) are designed so that between the bolt (6) and the retaining means (12 ) a given axial clearance is provided when said first bearing surface (9) comes into contact with said second bearing surface (10). 4. The locking unit (1) according to any of the previous paragraphs, in which the main body (5) or bolt has a passage (15) connecting the intermediate space (13) with the outer part of the locking unit (1) allowing movement of the balls (14) into the intermediate space (13) through the indicated passage (15). 5. The fixing unit (1) according to claim 4, in which the passage (15) contains closing means (18) for closing the passage (15). 6. The fixing unit (1) according to any one of the previous paragraphs, in which the main body (5) and the piston (4) contain a corresponding guide means configured to guide the piston (4) to move along the longitudinal axis (11) and prevent joint rotation of the piston with the bolt (6). 7. The fixing unit (1) according to claim 6, wherein the guide means comprises at least one protrusion (16) provided on the piston (4) and extending radially in an outer direction from the piston (4), wherein the main body (5) has at least one supporting surface (17) or recess running parallel to the longitudinal axis (11), wherein the supporting surface (17) or recess is configured to direct said protrusion (16) along the longitudinal axis (11) and prevent rotation of the piston (4). 8. A housing assembly for a holder, comprising a housing securing the assembly according to any one of claims. 1-7 and a projection or stop (18) configured to be attached to the holder to provide a means for attaching a piston of the locking assembly (1), allowing the main body (5) to move relative to the projection or stop (18) when the bolt (6) is rotated ).