Patent Application
20150211215
The present invention relates to the underlying structures for mechanical connection of wear parts and to means for wear part connection to such structures.
The present invention has been created in relation to buckets used by earthmoving equipment and to the connection of ground engaging tools to such buckets.
Ground engaging tools (GET), for earth-moving equipment, such as those used in mining operations, operate in a highly abrasive environment, are subjected to high impact forces and therefore wear out or become damaged through use. GET, such as teeth used on the front lip or edges of a bucket of the earth moving equipment, therefore require regular replacement.
Traditionally, GETs are welded onto the lips of buckets. When the GET come to the end of their useful life, they can be cut from the bucket, and new GET welded in their place.
The GET and the underlying structure of the bucket are subjected, in use, to high load forces and impacts. Traditionally the right angled corners of the buckets have been protected by GET (also called shrouds) mounted along the leading edge or lip of the floor of the bucket and also along the leading edge of the upright sides of the bucket. It has, however, been realised that load forces and impact at the respective corners between the upright sides and the bucket floor can cause fractures and potentially early failure of the material of the structure of the bucket at or adjacent the corners. Often the corners of buckets are precast in steel, and then the floor and remaining side structures and cast corners are welded together. This is a time consuming and costly process that must usually be done in a workshop to ensure accuracy and quality of reconstruction. Downtime of equipment also adds to loss of productivity and increased operating costs to a business. Structural failure of buckets is therefore to be avoided. The present invention has been realised with these problems in mind.
In addition, it will be appreciated that cutting and re-welding operations to replace welded -on GET are complex, time-consuming and relatively expensive. Further, as with repairs to buckets, they must generally be done in a workshop to ensure the cutting off and welding is done correctly, requiring the bucket to be transported away from the earth-moving equipment.
Various mechanical attachment methods have been proposed in an attempt to alleviate these problems. Many of the methods involve the use of bolts and similar fastening devices, inserted within the lip of the bucket. In general, such devices have proved to be of limited use. The insertion of a bolt or similar within a bucket lip can lead to undesirable stress concentrations within the lip, resulting in cracking of the bucket lip. Even where this is avoided, the large forces to which GET are exposed have a tendency to deform connecting bolts, thus making difficult their subsequent extraction using mechanical tools. Indeed, in some cases the deformation can be so severe that the GET must be cut away, completely negating any advantage of mechanical connection.
In response to these issues, the applicant has devised a number of mechanical connection means which overcome these problems. Examples of the applicant's devices are detailed in U.S. Pat. No. 7,219,454 and in U.S. Pat. No. 7,472,503 and in U.S. patent application Ser. No. 13/133,213 (also published as International PCT publication number WO 2010/065990), the contents of all of which are included herein by reference.
These connection means involve the use of a shroud which mounts about a lug or boss on the lip of an excavator bucket; a locking device which locates between the shroud and the boss; and the application of an external compressing force to maintain the relative position of the shroud, locking device and boss.
Although these connection means have proved far less susceptible to deformation than previous mechanical connectors, there have nonetheless been occasions where the connection means have had one or more problems. Sometimes failure of the GET or connection means can occur when the GET is in use due to a load being applied which is higher than the means can bear. The number of individual components forming the connection means can make fitting/refitting a GET time consuming. Other times, when it is necessary to remove the GET, the connection means is troublesome to undo to release the GET from the bucket, or, even if the connection means is released, the GET does not readily remove from the bucket lip, usually because of dirt and/or deformation of the connection means and/or GET preventing removal. A further form of the present invention has been devised with these problems in mind.
The present invention seeks to provide a means by which earthmoving equipment buckets are less prone to structural failure at the lower, and preferably connection of GET on earthmoving equipment can be substantially improved.
In accordance with a first aspect of the present invention there is provided an earthmoving equipment bucket corner including a first portion, a second portion and an intermediate portion extending between the first and second portions, wherein the first, second and intermediate portions are in different planes to one another.
Preferably the first portion provides a floor portion for the bucket, and preferably the second portion provides a wall portion for the bucket. The intermediate portion may connect the first and second portions.
The intermediate portion or the plane of the intermediate portion may be angled with respect to the first and second portions.
Preferably the corner is precast as a one piece component. Alternatively, the corner may be fabricated from multiple components, such as being welded from individual parts or a combination of cast and plate components.
The first and second portions may extend beyond a boundary of the intermediate portion and may connect together adjacent that boundary of the intermediate portion. The first and second portions may connect together in a continuum of material of the corner beyond the boundary of the intermediate portion.
The first and intermediate portions, and the second and intermediate portions, and preferably the first and second portions in the region beyond the boundary of the intermediate portion, may meet without a discontinuity of a sharp corner. The portions preferably meet at a radiused continuity of material rather than an abrupt deflection in the plane of each respective portion. Preferably the radius of curvature of the internal faces of the portions from one portion to the next is between 20 mm and 80 mm. This smooth radiused continuity form one portion to the next avoids sharp corners that otherwise create stress zones and likely failure points for the corner.
The corner may have a front peripheral region arranged to receive a boss, lug or adapter for mounting a ground engaging tool (GET) or wear plate to the corner. Hereinafter, the boss, lug or adapter are deemed equivalent and are each referred to as a ‘boss’ for ease of reading of this specification.
The boss may be welded to the intermediate portion or may be precast with the intermediate portion as a discrete part or as part of a cast corner.
The intermediate portion or the plane of the intermediate portion may be angled at between 120° and 170° with respect to one or both of the first and second portions. Thus, the intermediate portion or the plane of the intermediate portion may be angled at 120° with respect to one of the first or second portions, and at 150° with respect to the other of the first or second portions. Alternatively, the intermediate portion or the plane of the intermediate portion may be angled at 135° with respect to one or both of the first and second portions.
The first, second and/or intermediate portions may taper from a respective body portion of each to a narrower profile front edge of the front peripheral region.
The intermediate portion may blend into the first portion and/or into the second portion by a continuous curve of material. The continuous curve of material may be formed by casting the corner as a one piece component.
Preferably the corner widens between a front region and a rear region of the corner. The front region includes the front boundary with the tapered edge to receive a GET. The rear region is arranged to be connected, such as by welding, to a body of the bucket.
The corner may include a first exterior surface that forms part of an interior bowl of a bucket for receiving material into the bucket, and a second exterior surface that forms part of an exterior surface of the bucket for contact with material exterior to the bucket. The second exterior surface of the corner may include a recessed region, which may receive part of a ground engaging tool mounted to the corner.
The rear exterior region of the corner beyond the recessed region may widen out the corner so that a greater amount of material may be included in the corner, such as for added strength, impact and deformation resistance and longevity of the corner, and ultimately the bucket, in use.
The plane of the first portion may meet the plane of the intermediate portion at an included angle of between around 100° to 175°. Preferably the included angle is between around 120° and 170°, and more preferably between 120° and 150°. Similarly with the included angle between the plane of the second portion and the plane of the intermediate portion.
A further aspect of the present invention provides a ground engaging tool (GET) including a wear part for engagement with material when in use and a mounting portion to mount the GET to earthmoving equipment, the mounting portion including an internal opening into the GET, the opening having a first GET portion, a second GET portion and an intermediate GET portion between the first and second GET portions, wherein the first, second and intermediate GET portions are in different planes to one another.
The first, second and intermediate GET portions are preferably arranged and configured such that the opening into the GET receives respectively a first bucket corner portion, a second bucket corner portion and an intermediate bucket corner portion of a bucket corner, the first, second and intermediate bucket corner portions are also in different planes to one another.
The GET may provide a wear part to protect the corner of the bucket. The bucket corner may transfer load and impact forces from the GET to the side and/or floor of the bucket.
The GET may be a corner GET in that the GET protects the corner and is arranged to be mounted at the end of a row of GETS mounted to a front edge or lip of a bucket. The corner GET may provide a wedge of wear material such that the corner GET is thicker at its outer edge to protect an outermost side boundary of the bucket corner than the inner edge of the corner GET arranged to be adjacent to another GET.
The GET may mount to the bucket corner by a connection means. The connection means may be inserted into a recess into the GET. The recess may open into or connect with or form part of the opening in the GET to receive a portion of the bucket corner therein.
The GET may have a blade portion that broadens outwards from a connection portion of the GET for mounting the GET to the edge or lip of the bucket to the leading edge of the blade portion of the GET. Alternatively, or in addition, the blade portion of the GET deviating or deflecting to one side with respect to the connection portion. Thus, the GET may angle outwards with respect to a bucket to which it is to be mounted.
The GET may have an inner face that abuts, in use, a next adjacent GET, the inner face angled outwards from the bucket edge or lip to a leading edge of the GET. This allows a standard GET to be mounted next adjacent to the corner GET, thereby avoiding the need for an intermediate type GET with a tapered blade. This reduces the need for an additional, tapered, type GET.
A further aspect of the present invention provides a ground engaging tool (GET) system, including a GET, a bucket corner and a GET connection means, the GET including a wear part for engagement with material when in use and a mounting portion to mount the GET to earthmoving equipment, the mounting portion including an internal opening into the GET, the opening having a first GET portion, a second GET portion and an intermediate GET portion between the first and second GET portions, wherein the first, second and intermediate GET portions are in different planes to one another, the first, second and intermediate GET portions are preferably arranged and configured such that the opening into the GET receives respectively a first bucket corner portion, a second bucket corner portion and an intermediate bucket corner portion of a bucket corner, the first, second and intermediate bucket corner portions are also in different planes to one another, and the connection means arranged to connect the GET to the bucket corner.
Preferably the connection means is a releasable device such that the GET can be releasably tightened to the bucket corner and released by un-tightening the connection means to remove the GET.
The bucket corner of the present invention beneficially reduces stress points and smoothes transitions between faces to help distribute forces through two transition points where faces meet rather than through one transition point at the corner of a regular ‘square’ bucket corner.
The present invention also increases the bearing surface for a GET closer to where impacts are felt through the corner.
Also, the shape and configuration of the angled faces provides for an area of relief under the corner to give more space for GET (shroud) material, therefore further saving on bucket corner wear because the corner wears out less quickly, and thereby saving on costly downtime to remove and repair the bucket.
The plane of the intermediate portion may meet the plane of the first portion (the floor of the bucket) an exterior angle of between 15° and 25° with respect to the plane of the first portion. That is, the intermediate portion may project from the plane of the floor of the bucket by an angle of between 15° and 25° . Preferably that angle is between 18° and 22°, and more preferably substantially or generally 20°;
This shallower angle (shallower than a 30° angle) lowers the effective height extent of the corner. The shallower angle also lowers fatigue on the material of the corner at the transitions from one surface to the next, especially at the radiused transitions from the intermediate portion to each of the first and second portions. The shallower angle also helps reduce weight from the corner shroud due to the decreased height, and also gives improved perceived or actual penetration of the bucket into material to be picked up by the bucket. Reducing the angle to give a lower height corner also improves shroud engagement to the corner during fitment of the shroud.
It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently, the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:
As shown in
The intermediate portion is angled relative to both the first and second portions. Thus, instead of a traditional 90° internal corner where the side wall and floor of the bucket meet at the corner, the corner of the present invention provides an angled corner face.
The first portion has a wall 34 that forms part of the floor of the bucket when welded into place. This wall has a taper or bevel 36 towards a forward edge thereof.
The second portion 14 forms part of the side wall of a bucket when welded into place. The second portion includes a wall 20 with a leading flared wall portion 22 that widens the corner at the front 28 thereof with respect to the rear 30 thereof. The wall also has a straight rear portion 24. The leading portion also has a taper 26.
The intermediate portion provides a wall 32 between the first and second portions. However, the walls 24, 34 of the respective first and second portions meet 41 beyond the boundary 38 of the intermediate portion.
The intermediate portion is preferably at an included angle α, β of around 120° to 170° with respect to the respective walls of the first and second portions.
As shown in
A lower profile boss 100 is mounted to the front edge of the bucket lip 36. In the embodiment shown, the front portion 102 of the boss 100 extends only partway down the thickness TL of the lip front edge 104. This provides a corner formed by the underside of the front portion of the boss and the upright exposed front edge of the bucket lip, which gives an improved bearing surface for a stronger mounting of the shroud to the lip.
As can be seen in
The pin block 110 in
A corner ground engaging tool 112 is shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012903828 | Sep 2012 | AU | national |
| 2013901488 | Apr 2013 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2013/001899 | 9/4/2013 | WO | 00 |
