US20100232919A1

US20100232919A1 - Pivoting implements and adjustment arrangements for earth moving or materials handling machines

Info

Publication number: US20100232919A1
Application number: US12/596,828
Authority: US
Inventors: Matthew James Calvert
Original assignee: Wedgelock Equipment Ltd
Current assignee: Cascade Corp
Priority date: 2008-04-15
Filing date: 2009-04-15
Publication date: 2010-09-16
Also published as: MX2009011386A; WO2009128732A1; CA2683130A1

Abstract

An implement pivots with respect to an earth moving or materials handling machine to which the implement is attached. The implement may be a bucket adapted to pivot laterally with respect to an excavator or other machine to which the bucket is attached. An adjustment arrangement includes a linear actuator which operates along a substantially fixed axis to drive the pivoting movement. The linear actuator may drive a rack which engages with a pinion to cause pivoting movement.

Description

FIELD OF THE INVENTION

The invention relates to pivoting implements for attachment to earth moving or materials handling machines.

BACKGROUND TO THE INVENTION

Earth moving or materials handling machines can be adapted for and/or used in various applications including construction, earthworks, demolition, forestry, drainage, quarrying, mining etc. Implements are attached to the machine, for example to the arm of an excavator. Implements include buckets, rippers, ploughs, rakes, spades and rollers.
Some excavator buckets are capable of adjustable pivoting with respect to the machine. This is generally achieved using a pivot between the main body of the bucket and a coupling part of the bucket. The bucket may be connected to an excavator by the coupling part. One or two hydraulic cylinders are connected to the bucket and to the coupling part and drive rotation of the bucket with respect to the coupling part. The coupling part remains fixed with respect to the excavator.
Due to the pivoting motion of the bucket, the cylinders must be attached so as to pivot freely around their attachment points at each end. In general, pivoting connections are provided at each end of each cylinder. These are common failure points, since adjustment creates wear in the connection and also because lateral loads imposed on the bucket during use are transmitted through these connections.
It is an object of the invention to provide an improved pivoting mechanism and/or an improved pivoting implement for an earth moving or materials handling machine, or at least to provide the public with a useful choice.

SUMMARY OF THE INVENTION

In a first broad aspect the invention provides an implement configured for adjustable pivoting with respect to an earth moving or materials handling machine to which the implement is, in use, attached, including:
an implement body;
a coupling section for attachment of the implement to an earth moving or materials handling machine;
a linear actuator operating along an axis which is substantially fixed relative to an attachment point of the actuator;
an engagement element configured to be driven by the linear actuator; and
a rotator element configured to engage with the engagement element such that motion of the engagement element drives rotational motion of the implement body relative to the coupling section.
Preferably the linear actuator is a hydraulic ram.
Preferably the implement includes two linear actuators operating along the axis and driving the engagement element.
Preferably the engagement element is connected to the linear actuator. Preferably the linear actuator is a hydraulic ram and the engagement element is connected to the rod of the ram.
Preferably the engagement element and the rotator element are formed with cooperating teeth.
Preferably the engagement element is a rack. Preferably the rotator element is a pinion.
Preferably the rotator element is mounted to the coupling section.
Preferably the linear actuator is mounted to the body of the implement.
Preferably the implement is configured to provide lateral pivoting of the body of the implement.
Preferably the implement includes a cover to substantially enclose the linear actuator, engagement element and rotator element.
In a second broad aspect the invention provides an adjustment mechanism for pivoting an implement with respect to an earth moving or materials handling machine to which the implement is, in use, attached, the implement including an implement body and a coupling section, the adjustment mechanism including:
a linear actuator operating along an axis which is substantially fixed relative to an attachment point of the actuator;
an engagement element configured to be driven by the linear actuator; and
a rotator element configured to engage with the engagement element such that motion of the linear actuator drives rotational motion of the implement body.
Preferably the linear actuator is a hydraulic ram.
Preferably the mechanism includes two linear actuators operating along the axis and driving the engagement element.
Preferably the engagement element is connected to the linear actuator. Preferably the linear actuator is a hydraulic ram and the engagement element is connected to the rod of the ram.
Preferably the engagement element and the rotator element are formed with cooperating teeth.
Preferably the engagement element is a rack. Preferably the rotator element is a pinion.
Preferably the rotator element is configured for mounting to an implement's coupling section.
Preferably the linear actuator is configured for mounting to the body of an implement.
Preferably the adjustment mechanism is configured to be positioned between an implement's body and coupling section.
Preferably the mechanism is configured to provide lateral pivoting of the body of the implement.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an implement according to one embodiment;

FIG. 2 is a second perspective view of the implement of FIG. 1;

FIG. 3 is an exploded view of the adjustment mechanism of the implement of FIG. 1;

FIG. 4 is a side view of the assembled adjustment mechanism of FIG. 3;

FIG. 5 is an exploded view of the top plate, rotator element and shaft assembly of the implement of FIG. 1;

FIG. 5A is a cross-section through the top plate, rotator element and shaft assembly of FIG. 5;

FIG. 6 is a cross-section along the line 6-6 in FIG. 4;

FIG. 7 is a schematic force diagram showing forces acting in the implement of FIG. 1; and

FIG. 8 is a schematic force diagram showing forces acting in a prior art implement.

DETAILED DESCRIPTION

FIGS. 1 and 2 are perspective views of an implement 1 including an adjustment mechanism 2. The implement shown is a bucket suitable for attachment to an excavator, but the invention may be applied to other implements for use with any suitable earth moving or materials handling machines.
Implements include buckets, rippers, ploughs, rakes, spades, rollers or any other implements for attachment to earth moving or materials handling machines.
Earth moving or materials handling machines can be adapted for and/or used in various applications including construction, earthworks, demolition, forestry, drainage, quarrying, mining etc. The term “earth moving or materials handling machine” includes machines used in these and other applications. In particular, earth moving and materials handling machines include excavators and telehandlers.
A coupling section 3 allows connection of the implement 1 to an excavator arm or quick hitch arrangement, or to another earth moving or materials handling machine, as will be understood by a skilled reader.
The adjustment mechanism 2 allows the body 4 of the implement 1 to pivot laterally with respect to the coupling section 3, and therefore with respect to a machine to which the implement is, in use, attached.
FIG. 3 is an exploded view showing some components of the adjustment mechanism. The adjustment mechanism includes a top plate 10 to which the coupling section 3 may be attached. A rotator element 11 and a shaft 12 are mounted to the underside of the top plate 10. The shaft 12 includes a central bore 13 which receives a pin 14, such that the pin 14 can rotate with respect to the shaft 12, rotator element 11 and top plate 10.
The pin 14 is supported and connected at each end to the body 4 of the implement 1 as follows. A front plate is formed from a front plate main bearer 16 and a front plate laminate 17. A back plate is formed from a back plate bearer 18 and a back plate laminate 19. Both the front plate and the back plate are connected, preferably welded, to the body 4 of the implement 1 as is clear from FIGS. 1 and 2.
The back plate and the front plate each include a bore 21, 22 dimensioned to receive the main shaft of the pin 14. These bores may be formed after the back and front plates have been connected to the implement body 4. The pin includes a flange 24 at one end and a head 25 at the other end. The head is configured for attachment to the pin after the pin has been inserted through the bores 21, 22 of the front and back plates and the bore 13 of the shaft 12.
FIG. 4 is a side view of the adjustment mechanism 2. This view shows the assembled positions of the various components. A base plate 30 is connected between the front plate bearer 16 and the back plate bearer 18, with the front and back plate laminates 17, 19 sitting on top of the base plate 30. The base plate provides structure and facilitates connection of one or more linear actuators, as will become apparent below. The base plate also prevents contamination of the adjustment mechanism from material (e.g. soil) carried in the body 4 of the bucket.
FIG. 4 also shows how the top plate 10 is supported on the shaft 12 by the rotator element 11 and a support element 31.
FIG. 5 is an exploded view of the top plate 10, rotator element 11 and shaft 12 assembly. The shaft 12 includes a pair of bosses 32, 33. The first boss 32 engages with a bore 34 in the rotator element 11, while the second boss 33 engages with the shaped lower edge 35 of the support element 31. A spacer 36 sits between the two bosses 32, 33 while one or more bushes 37 sit inside the bores 38 of the bosses 32, 33. In turn the pin 14 (FIG. 3) sits within the bore 13 formed by the internal surfaces of the bushes 37. The bushes therefore serve to reduce friction caused by rotational movement of the pin 14 with respect to the shaft 12.
FIG. 5A shows a cross-section along the length of the assembled top plate 10, rotator element 11 and shaft 12 assembly.
Thus, the pin 14, which is fixed to the body 4 of the implement 1, is free to rotate within the shaft 12.
Returning to FIG. 3, the adjustment mechanism 2 also includes an engagement element 40 which engages with the rotator element 11. The engagement element 40 and the rotator element 11 may be cooperating gears, formed with cooperating teeth. In the embodiment shown, the engagement element 40 and the rotator element 11 form a rack and pinion mechanism, such that linear motion of the engagement element 40 relative to the body 4 of the implement 1 drives rotational motion of the implement body 4 about the rotator element 11.
The engagement element 40 is itself driven by one or more linear actuators 41 (FIG. 1). The actuators may be hydraulic cylinders. For large implements which are both heavy and designed to carry heavy loads, two hydraulic cylinders may be preferred as shown in FIGS. 1 and 2. For smaller implements or those where smaller loads are expected a single hydraulic cylinder may be sufficient.
The hydraulic cylinders 41 may reside in a shaped recess 42 in the base plate 30. This means that the rod 44 of each hydraulic cylinder 41 is positioned at an appropriate height to drive motion of the engagement element 40, as will be described below.
A cylinder bracket 45 is provided at each side of the adjustment mechanism. The brackets 45 may be shaped to fit the recess 42 in the base plate 30 and may be welded to the base plate 42 as shown in FIG. 4.
The casing of each hydraulic cylinder 41 is connected to a cylinder bracket 45. Since the motion of the cylinder rod 44 is substantially linear, there is no need for the cylinder to rotate at the connection to the bracket 45. This can therefore be a simple, fixed connection.
Thus the linear actuator operates along an axis which is substantially fixed relative to the body 4 of the implement 1, and therefore relative to the connection point where the linear actuator is connected to the body 4. Here, “substantially fixed” means that the axis is sufficiently independent of the degree of extension of the linear actuator that no rotating connection between the linear actuator and the body 4 of the implement 1 is required.
The rod 44 of each hydraulic cylinder 41 is connected at its distal end to a connector 47. The connector 47 is fixed to the engagement element 40 by appropriate fasteners.
Thus the hydraulic cylinders 41 operate to drive the connector 47 and engagement element 40 in linear motion relative to the body 4 of the bucket 1, from side to side across the bucket 1. The engagement element therefore moves parallel to the axis of the hydraulic cylinders 41.
FIG. 6 is a cross-section along the line 6-6 in FIG. 4. This shows the hydraulic cylinders 41 and the connection of the rods 44 to the connector 47. The teeth 49 of the engagement element 40 engage with the teeth 50 of the rotator element 11. Thus, linear motion from the hydraulic cylinders is transmitted via the connector 47 and engagement element 40 to drive rotational motion of the body 4 of the implement 1 relative to the rotator element 11.
FIG. 7 is a schematic force diagram of the Applicant's mechanism. One end of a linear actuator (not shown) is connected to the implement body at point 70. The implement body rotates about a pivot point 72. The linear actuator (either extending or retracting) always acts to apply a force along an axis (indicated by arrow 73) which is tangential to the circumference of the rotator element 71. Therefore, irrespective of the pivot angle of the implement, the radius r from the pivot point 72 to the force vector 73 remains the same. Therefore, maximum torque is available irrespective of pivot angle.
Where two hydraulic cylinders are used, both will act along the same axis tangential to the circumference of the rotator element 71.
FIG. 8 is a schematic force diagram of a prior art mechanism. One end of a hydraulic cylinder is connected to the bucket body 79 at point 80. A second hydraulic cylinder is connected to the bucket body 79 at point 81. The bucket body is configured to rotate about a point 82. The other end of each hydraulic cylinder is connected at point 83.
The hydraulic cylinders therefore exert forces in the directions indicated by the arrows 84, 85. The radii r′, r″ from the pivot point 82 to the force vectors 84, 85 are dependent on the pivot angle and are significantly reduced for large pivot angles. Therefore, at large pivot angles larger forces are required to achieve the same torque.
Therefore, the Applicant's mechanism provides even torque over the entire pivot range. This means that a less powerful linear actuator, or a smaller number of actuators, can be used or that better performance can be obtained over the entire pivot range for a given size of actuator than in prior mechanisms.
In the Applicant's mechanism, linear actuators do not rotate around their end connections. This reduces the number of parts since, for example, bushes are not required at these connections. Furthermore, this reduces wear and improves reliability.
An alternative embodiment may have the rotator element fixed to the body 4 of the implement 1, while the linear actuators are fixed relative to the coupling section 3.
While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.

Claims

1. An implement configured for adjustable pivoting with respect to an earth moving or materials handling machine to which the implement is configured to be, in use, attached, including:

an implement body;

a coupling section for attachment of the implement to an earth moving or materials handling machine;

an engagement element in linear sliding engagement with the implement body;

a linear actuator having a first end fixed to the implement body and a second end fixed to the engagement element, the linear actuator being configured to drive the engagement element in sliding motion relative to the implement body along a substantially linear path; and

a rotator element configured to engage with the engagement element such that motion of the engagement element relative to the implement body drives the implement body to pivot relative to the coupling section.

2. An implement as claimed in claim 1 wherein the linear actuator is a hydraulic ram.

3. An implement as claimed in claim 1 including two linear actuators operating along a common linear path and driving the engagement element.

4. (canceled)

5. An implement as claimed in claim 1 wherein the linear actuator is a hydraulic ram and the engagement element is connected to the rod of the ram.

6. (canceled)

7. An implement as claimed in claim 1 wherein the engagement element is a toothed rack.

8. An implement as claimed in claim 7 wherein the rotator element is a pinion.

9. An implement as claimed in claim 8 wherein the rotator element is fixed mounted to the coupling section.

10.-12. (canceled)

13. An adjustment mechanism for pivoting an implement with respect to an earth moving or materials handling machine to which the implement is configured to be, in use, attached, the implement including an implement body and a coupling section, the adjustment mechanism including:

an engagement element in linear sliding engagement with the implement body;

14. An adjustment mechanism as claimed in claim 13 wherein the linear actuator is a hydraulic ram.

15. An adjustment mechanism as claimed in claim 13 including two linear actuators operating along a common linear path and driving the engagement element.

16. (canceled)

17. An adjustment mechanism as claimed in claim 13 wherein the linear actuator is a hydraulic ram and the engagement element is connected to the rod of the ram.

18. (canceled)

19. An adjustment mechanism as claimed in claim 13 wherein the engagement element is a toothed rack.

20. An adjustment mechanism as claimed in claim 19 wherein the rotator element is a pinion.

21. An adjustment mechanism as claimed in claim 20 wherein the rotator element is configured for fixed mounting to an implement's coupling section.

22. (canceled)

23. An adjustment mechanism as claimed claim 13 configured to be positioned between an implement's body and coupling section.

24. An adjustment mechanism as claimed in claim 13 configured to provide lateral pivoting of the body of the implement relative to the coupling section.

25.-28. (canceled)