EP4299836A1

EP4299836A1 - Bucket stopper plate and lift arm comprising bucket stopper plate

Info

Publication number: EP4299836A1
Application number: EP22182534.2A
Authority: EP
Inventors: Jouni AHTIAINEN
Original assignee: Sandvik Mining and Construction Oy
Current assignee: Sandvik Mining and Construction Oy
Priority date: 2022-07-01
Filing date: 2022-07-01
Publication date: 2024-01-03

Abstract

A bucket stopper plate (1) for an underground loader, wherein the bucket stopper plate is configured to be fastened to a lift arm of the underground loader, wherein the bucket stopper plate (1) comprises a top surface (2), at least two sections, an end section (3) and a central section (4) arranged sequentially in the same plane, and the end section (3) comprises an opening (5).

Description

TECHNICAL FIELD

The present invention relates to bucket stoppers plates.

BACKGROUND OF THE ART

Many underground loaders and loading devices which are used for lifting heavy material, such as rocks, comprise a bucket, which is used for lifting and transferring material from one place to another, e.g. into a truck, dump truck or some pile of material. The bucket is fastened to a lift arm or lift arms so that the bucket may reach to desired location. The bucket is a heavy component, especially when loaded, and for example in transfer position it is always tilted against the lift arm. Therefore, the lift arm is subjected to great forces caused by the impacts from the bucket as well as tensile load caused by the heavy loads. It may eventually break and then it must be replaced or repaired before continuing operation.
To protect the lift arm, it is known to use bucket stopper plates which are fastened to the lift arm so that the bucket stopper plate, or the bucket stopper if such is fastened to the plate, limits the movement of the bucket and receives the impact from the bucket. However, the location of the bucket stopper plates is very sensitive, and welding and manufacturing defects have caused plenty of cracks in the lift arms. For example, when the bucket is loaded, the top surface of the lifting arm, to which the bucket stopper plate is fastened, is subjected to great tensile load. Each fastening point, e.g. weld, causes discontinuity to the stress field, which may damage the lift arm. Especially, transverse welds and end points of longitudinal welds are critical and prone to break or cause damage to the lift arm. Further, limiting the movement of the bucket with the bucket stopper plates protects bucket moving elements, such as hydraulic cylinders.

OBJECTIVE OF THE INVENTION

The objective of the device is to alleviate the disadvantages mentioned above.
In particular, it is an objective of the present device to provide a bucket stopper plate having a higher life prediction.

SUMMARY

According to a first aspect, the present invention provides a bucket stopper plate for an underground loader, wherein the bucket stopper plate is configured to be fastened to a lift arm of the underground loader, wherein the bucket stopper plate comprises a top surface, at least two sections, an end section and a central section arranged sequentially in the same plane, and the end section comprises an opening.
The bucket stopper plate fastened to a lift arm causes stiffened area to the lift arm and the areas where the stiffness changes, i.e. at the stopper plate ends, are subjected to great tensions. The advantage of the present device is that it has more flexible structure and the difference of stiffness is smaller at the stopper plate end. Solution is also cheaper and has better fatigue resistance comparing to the known solutions.
In an embodiment, the end section comprises a curved edge at the opposite end to the central section.
The advantage of the embodiment is that the stopper plate may be welded all around without need of any transverse welds, which would be perpendicular to the tensile stress.
In an embodiment, the curved edge has a shape of circular arc having radius R from axis perpendicular to the top surface.
In an embodiment, the curved edge has a shape of semicircle.
In an embodiment, the opening has a shape of a semicircle.
In an embodiment, corners of the semicircular opening are rounded.
In an embodiment, the central section comprises threaded holes for fastening auxiliary components to the bucket stopper plate.
In an embodiment, the bucket stopper plate is a solid plate.
In an embodiment, comprising two end sections arranged on opposite sides of the central section.
In an embodiment, the bucket stopper plate is formed of two parts each having an end section and a central section, so that the two parts are arranged sequentially in the same plane and the central sections are between the end sections.
According to a second aspect, the present invention provides lift arm of an underground loader, wherein the lift arm comprises at least one bucket stopper plate according to any one of previous embodiments.
In an embodiment, the bucket stopper plate is welded to the lift arm.
In an embodiment, the weld continues completely around the perimeter of the bucket stopper plate.
It is to be understood that the aspects and embodiments of the invention described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings:

Fig. 1 shows a bucket stopper plate 1, which is formed of two similar parts, and which are fastened to each other,
Fig. 2 shows same kind of a bucket stopper plate as figure 1, but is made of two separate parts, and
Fig. 3 shows a lifting element of an underground loader comprising two lift arms each having a bucket stopper plate.

DETAILED DESCRIPTION

Bucket stopper plate is a component which is fastened to a lift arm of an underground loader etc. for limiting the movement of the bucket and for protecting the lift arm from impacts caused by the bucket when it is tilted backwards against the lift arm. Further, some dampening component, e.g. a rubber block, is be fastened between the bucket and the bucket stopper plate, e.g. to the bucket stopper plate or to the bucket, for dampening the impacts.
Figure 1 shows a bucket stopper plate 1, which is formed of two similar parts, and which are fastened to each other. Optionally, the parts may have different shapes, i.e. they are not similar. Each part comprises an end section 3 and a central section 4, which are sequentially in the same plane, i.e forming a platelike structure. The end section 3 and the central section 4 are same solid component, but optionally they may be separate components fastened to each other. The bucket stopper plate comprises a top surface 2, which is facing outwards when the bucket stopper plate is fastened to the lift arm. The end section 3 comprises an opening 5 for providing more flexible structure reducing stress and giving higher life prediction to the plate and especially to the fastening points of the plate, e.g. welds, and to the lift arm to which the plate is fastened. Because of the opening 5 at the end section, the difference of stiffness is not that high at the bucket stopper plate end.
The end section comprises a curved edge 6 which forms the end of the bucket stopper plate 1. The curved edge 6 is at the opposite end to the central section 4. The opening is between the curved edge 6 and the central section 4. The curved edge 6 may have a shape of a circular arc, i.e. curved line having radius R form axis perpendicular to the top surface 2. The curved edge 6 may have a shape of semicircle, i.e. the curved section of the perimeter of the semicircle. Optionally, the rounding may be uneven, e.g. the rounding R is smaller at the end of the curved edge and greater at the center of the curved edge. The wall thickness between the opening 5 and the curved edge 6 may be for example 5, 7, 10, 12, 15 or 20 mm. Optionally, the wall thickness between the opening 5 and the curved edge 6 may be 5 to 10 mm, 5 to 15 mm, 5 to 20 mm, 7 to 12 mm, 7 to 15 mm, 7 to 20 mm, 10 to 15 mm or 10 to 20 mm.
The opening 5 may have different shapes. The opening may have a shape of a semicircle, i.e. having a linear section and a curved section, e.g. arc. The linear section is on the side, which is towards the central section 4, and the curved section is towards the curved edge 6. The curved section shape may correspond the shape of the curved edge but having a smaller diameter, i.e. the curved section and the curved edge are part of coaxial circles. Corners 7 of the semicircular opening, i.e. sections connecting the linear section and the curved sections, may be rounded. The rounding may be for example 10, 15, 20 or 25 mm.
The bucket stopper plate 1 may comprise threaded holes 8, which are arranged on the top surface 2. The threaded holes may be used for fastening auxiliary components to the bucket stopper plate. The auxiliary component may be for example a rubber block, fender or other dampening element for receiving the impacts from the bucket.
As seen in figure 1, the bucket stopper plate may comprise two parts, which may be similar, fastened to each other. Each part has end section 3 and a central section 4, and the parts are fastened together sequentially so that the central sections are between the end sections in the same plane.
Figure 2 shows same kind of a bucket stopper plate as figure 1, but instead of two separate parts, the whole plate is formed of one solid plate having two end sections and central section(s) between the end sections.
Figure 3 shows lifting means of an underground loader comprising two parallel lifting arms 11, which may be fastened to each other. Each lifting arm comprises one bucket stopper plate 1 fastened on a top surface for receiving impacts of a bucket when it is tilted backwards towards the lifting arms. In figure 3, the bucket stopper plate is made of one solid plate having two end sections and central section(s) between the end sections. However, the bucket stopper plate may be made of two parts, each having a central section and end section, which two parts are connected to each other so that the central sections are between the end sections (as explained above). The bucket stopper plate 1 is fastened to the lift arm by welding. The weld may continue completely around the perimeter of the bucket stopper plate 1.
Although the invention has been the described in conjunction with a certain type of device, it should be understood that the invention is not limited to any certain type of device. While the present inventions have been described in connection with a number of exemplary embodiments, and implementations, the present inventions are not so limited, but rather cover various modifications, and equivalent arrangements, which fall within the purview of prospective claims.

Claims

A bucket stopper plate (1) for an underground loader, wherein the bucket stopper plate is configured to be fastened to a lift arm of the underground loader, wherein the bucket stopper plate (1) comprises
- a top surface (2),

- at least two sections, an end section (3) and a central section (4) arranged sequentially in the same plane,
charcterizedin that
the end section (3) comprises an opening (5).
The bucket stopper plate (1) according to claim 1, wherein the end section (3) comprises a curved edge (6) at the opposite end to the central section (4).
The bucket stopper plate (1) according to claim 2, wherein the curved edge (6) has a shape of circular arc having radius R from axis perpendicular to the top surface (2).
The bucket stopper plate (1) according to claim 2, wherein the curved edge (6) has a shape of semicircle.
The bucket stopper plate (1) according to any one of claims 1 to 4, wherein the opening (5) has a shape of a semicircle.
The bucket stopper plate (1) according to claim 5, wherein corners (7) of the semicircular opening (5) are rounded.
The bucket stopper plate (1) according to any one of claims 1 to 6, wherein the central section (4) comprises threaded holes (8) for fastening auxiliary components to the bucket stopper plate.
The bucket stopper plate (1) according to any one of claims 1 to 7, wherein the bucket stopper plate is a solid plate.
The bucket stopper plate (1) according to any one of claims 1 to 8, comprising two end sections (3) arranged on opposite sides of the central section (4).
The bucket stopper plate (1) according to any one of claims 1 to 8, wherein the bucket stopper plate is formed of two parts each having an end section (3) and a central section (4), so that the two parts are arranged sequentially in the same plane and the central sections are between the end sections.
A lift arm (11) of an underground loader, wherein the lift arm comprises at least one bucket stopper plate (1) according to any of claims 1 to 10.
The lift arm according to claim 11, wherein the bucket stopper plate (1) is welded to the lift arm (11) .
The lift arm according to claim 12, wherein the weld (9) continues completely around the perimeter of the bucket stopper plate (1).