WO2012068643A1

WO2012068643A1 - A lock for an excavator wear assembly

Info

Publication number: WO2012068643A1
Application number: PCT/AU2011/001543
Authority: WO
Inventors: Miguel Guimaraes
Original assignee: Cqms Pty Ltd
Priority date: 2010-11-26
Filing date: 2011-11-28
Publication date: 2012-05-31

Abstract

A lock for an excavator wear assembly, the lock comprising: a first member having a retaining member, the retaining member having at least one first bearing face; a second member having a retaining recess, the retaining recess having at least one second bearing facing; the retaining recess adapted to releasably receivable the retaining member of the first member so that the first bearing face bears against the second bearing face; wherein the at least one first bearing face and the at least one second bearing face are inclined with respect to a longitudinal axis that extends through the first member and the second member when the retaining member of the first member is received within the retaining recess of the second member.

Description

TITLE

"A LOCK FOR AN EXCAVATOR WEAR ASSEMBLY"

FIELD OF THE INVENTION

This invention relates to a lock for an excavator wear assembly. In particular, although not exclusively, the invention relates to a lock for releasably securing an excavator tooth to a nose of an excavator bucket or to an adaptor releasably secured to a nose of an excavator bucket.

BACKGROUND TO THE INVENTION

Excavator tooth assemblies mounted to the digging edge of excavator buckets and the like generally comprise a replaceable digging tooth, an adaptor body and an adaptor nose which is secured by welding or the like to the digging edge of a bucket or the like. The tooth generally has a socket-like recess at its rear end to receivably locate a front spigot portion of the adaptor nose and a removable locking pin is generally employed to releasably secure the tooth on the adaptor.

In use, excavator teeth are subjected to extensive load forces along a longitudinal axis of a tooth as well as in vertical and transverse directions. A snug fit is required between the digging point and the front portion of the adaptor and also between the adaptor socket and the nose spigot portion and their respective mounting pins to avoid premature wear between the components. As the various components wear, the locking pins can loosen thereby increasing the risk of loss of a digging point or an entire adaptor/tooth combination. This necessitates considerable downtime to replace the lost wear members and where items, such as locking pins, are not recovered, these can cause damage and/or further downtime in downstream operations, such as ore crushing and the like.

The greatest loads experienced by excavator tooth assemblies are vertical loads which tend to generate large moment forces capable of rotating a tooth off the front of an adaptor and/or rotating the adaptor off the adaptor nose. In addition, twisting or "yaw" loads are frequently imposed on such tooth assemblies. Despite many prior art attempts to improve the mounting of a wear member to a nose of an excavator, most of these proposals suffer from one or more deficiencies.

While generally satisfactory for their intended purpose, the prior art all suffer from one or more shortcomings or disadvantages in terms of inadequate resistance to rotation of a tooth off a nose or an adaptor under the influence of vertical loads applying a rotational moment to the tooth, a predisposition to premature wear, difficulties in retention of the teeth on noses or adaptors, inadequate locking systems and unduly complicated configurations giving rise to increased fabrication costs.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

OBJECT OF THE INVENTION

It is an object of the invention to overcome or at least alleviate one or more of the above problems and/or provide the consumer with a useful or commercial choice.

DISCLOSURE OF THE INVENTION

In one form, although it need not be the only or indeed the broadest form, the invention resides in a lock for an excavator wear assembly, the lock comprising:

a first member having a retaining member, the retaining member having at least one first bearing face;

a second member having a retaining recess, the retaining recess having at least one second bearing facing; the retaining recess adapted to releasably receivable the retaining member of the first member so that the first bearing face bears against the second bearing face;

wherein the at least one first bearing face and the at least one second bearing face are inclined with respect to a longitudinal axis that extends through the first member and the second member when the retaining member of the first member is received within the retaining recess of the second member. Preferably, a fastener is releaseably fastened to the retaining member to secure the first member to the second member A fastener recess may be located within the second member to locate the fastener.

A fastening portion may form part of the retaining member. The fastening portion may be located externally on or located internally within the retaining member. Preferably, the fastening portion may be in the form of a fastening end. The fastening end is normally at least partially threaded. Alternatively, the fastening portion may be in the form of a fastening bore. The fastening bore is normally at least partially threaded.

The retaining recess and the retaining member are typically complementary in shape.

The retaining member is normally substantially frusto-conical in shape. However, it should be appreciated that the retaining member may be formed of other shapes. For example, the retaining member may be substantially pyramidal in shape.

The retaining recess is normally frusto-conical in shape. However, it should be appreciated that the retaining recess may be formed of other shapes. For example, the retaining recess may be substantially pyramidal in shape.

Typically, there is only a single first bearing face. However, it is envisaged that there may be 3, 4, 5, 6, 7, 8 or more first bearing faces.

Typically, there is only a single second bearing face. However, it is envisaged that there may be 3, 4, 5, 6, 7, 8 or more first bearing faces.

Suitably, the number of first bearing faces is equal to the number of second bearing faces.

Preferably, the majority of the at least first bearing face bears against the majority of the at least second bearing face.

In another form, the invention resides in an excavator wear assembly comprising:

an adaptor having a mounting spigot and a mounting aperture extending therethrough;

a wear member located over the mounting spigot of the adaptor, the wear member having an upper mounting aperture and lower mounting aperture;

a lock adapted to releasably secure the wear member to the adaptor, the lock comprising a first member locatable through the lower mounting aperture of the wear member and extending at least partially through the mounting aperture of the adaptor, the first lock member having a retaining member, the retaining member having at least one first bearing face; and a second member locatable through the upper mounting aperture of the wear member and at least partially though the mounting aperture of the adaptor, the second member having a retaining recess, the retaining recess having at least one second bearing face;

the retaining recess adapted to releasably receivee the retaining member of the first member so that the first bearing face bears against the second bearing face;

wherein the at least one first bearing face and the at least one second bearing face are inclined with respect to a longitudinal axis that extends through the first member and the second member when the retaining member of the first member is received within the retaining recess of the second member.

Further features of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, wherein:

FIG. 1A shows a perspective view of a lock for an excavator wear assembly according to an embodiment of the invention;

FIG. 1B shows an exploded perspective view of the lock shown in FIG. 1A;

FIG. 1C shows a sectional side view of the lock shown in FIG. 1A; FIG. 1D shows an exploded sectional side view of the lock shown in FIG. 1A;

FIG. 2A shows a perspective view of the excavator wear assembly according to an embodiment of the invention;

FIG. 2B shows an exploded perspective of the excavator wear assembly shown in FIG. 2A;

FIG. 2C shows a sectional side view of the excavator wear assembly shown in FIG. 2A;

FIG. 3A shows a perspective view of a lock for an excavator wear assembly according to an embodiment of the invention;

FIG. 3B shows an exploded perspective view of the lock shown in

FIG. 3A;

FIG. 3C shows a sectional side view of the lock shown in FIG. 3A; and

FIG. 3D shows an exploded sectional side view of the lock shown in FIG. 3A.

DETAILED DESCRIPTION OF THE INVENTION

The lock for an excavator for an excavator wear assembly is described with reference to an excavator wear member in the form of a tooth releasably secured to an adaptor. The adaptor is in turn secured to a nose of an excavator bucket or the like. A skilled addressee will appreciate that the invention may be employed to releasably secure an adaptor to a nose or a tooth directly to a nose of an excavator bucket lip.

FIGs 1A to 1D show a first embodiment of a lock 1000 for an excavator wear assembly according to a first embodiment of the invention.

The lock 1000 includes a first member 1100, a second member

1200, a fastener 1300 and a plug 1400. The first member 1100 is realeasably, slidably securable to the second member 1200.

The first member 1 100 includes a first block portion 1110, a first stem portion 1120 and a retaining member 1130. A first locating face 1111 forms part of the block portion 1 1 10.

The retaining member 1 130 is substantially frusto-concial in shape and extends from the first stem portion 1 120. A first bearing face 1 131 is formed on the retaining member 1130. The first bearing face 1131 is inclined with respect to a longitudinal axis 1500. The first bearing face 1131 forms a majority of a surface of the retaining member 1130. A fastening portion 1132, in the form of threaded, fastening end, is located at an end of the retaining member 1130.

The second member 1200 includes a second block portion 1210, a second stem portion 1220, a retaining recess 1230 and a fastener recess 1240. A locating face 1211 forms part of the block portion 1210.

The retaining recess 1230 is substantially frusto-concial in shape and located within the second stem portion 1220. A second bearing face 1231 is formed on the retaining recess 1230. The second bearing face 1231 is inclined with respect to a longitudinal axis 1500. The second bearing face 1231 forms a majority of a surface of the retaining member 1230. The fastener recess 1240 is located above and is joined to the retaining recess 1230. A shoulder 1241 is located at a base of the fastener recess 1240.

The fastener 1300 is in the form of a nut as is known in the art. The nut has an internal, threaded end to allow the nut to fit onto the fastening portion 1132.

The plug 1400 is a standard plug as is known in the art to keep fines from entering into fastener recess 1240 and subsequently the retaining recess 1230.

In order to secure the first member 1100 to the second member 1200, the retaining member 1130 is slid into the retaining recess 1230 until the threaded, fastening end 1231 of the retaining recess 1230 at least partially extends into the retaining recess 1230. The fastener 1300 is then screwed onto the threaded, fastening end 1130 which causes the fastener 1300 to bear against the shoulder 1241 of the fastening recess 1230. The continued rotation of the fastener 1300 subsequently causes the first bearing face 1131 of the retaining member 1130 to bear up against the second bearing face 1231 of the retaining recess 1230. Both the first bearing face 1131 and the second bearing face 1231 are inclined with respect to a longitudinal axis 1500 which extends through the first member 1100 and the second member 1200. Once the rotation of the fastener 1300 is ceased, the plug 1400 is located within the fastener 1300.

FIGs 2A to 2C show an excavator wear assembly 100 utilizing the lock 1000 shown in FIGs 1A to 1D. In this application, lock 1000 is used to releasably secure wear member in the form of a digging tooth 110 to an adaptor 120.

The tooth 110 has an upper mounting projection 111 , a lower mounting projection 112 and a rearwardly facing socket 113. An upper mounting aperture 114 extends through upper mounting projection 111 and a lower mounting aperture 115 extends through lower mounting projection 112.

The adaptor 120 has a mounting spigot 121 receivable within rearwardly facing socket 113 of tooth 110. An upper mounting recess 122 and a lower mounting recess 123 are located rearwardly of mounting spigot 121 on an upper and lower face respectively thereof. The adaptor 120 further includes a mounting aperture 124 extending through mounting spigot 121.

In order to lock the adaptor 120 to the tooth 110, the tooth 110 is located over the adaptor 120. Accordingly, the upper mounting projection 111 and lower mounting projection 112 of are located respectively within the upper mounting recess 122 and lower mounting recess 123 of the adaptor. Further, the mounting spigot 121 of the adaptor 120 is located within the facing socket 113 of the tooth 110.

Subsequently, the first member 00 is located though lower mounting aperture 1 5 of tooth 0 until the first locating face 1 of the first block portion 1110 is located on a lower surface of mounting spigot 121 of adaptor 120 adjacent the lower mounting recess 123 as shown. Accordingly, the first stem portion 1 20 of the first member 1100 is located within the mounting aperture 124 of the adaptor 20.

The second member 1200 is then located though upper mounting aperture 114 of tooth 110 until the second locating face 12 1 is located on an upper surface of mounting spigot 121 of adaptor 120 adjacent the upper mounting recess 122 as shown, Accordingly, the second stem portion 1220 of the second member 1100 is located within the mounting aperture 124 of the adaptor 120.

Consequently, the retaining member 1130 of the first member 10 is slid into the retaining recess 1230 of the second member 1200. The fastener 1300 is then attached to the fastening portion 1132 of the first member 1100 as described above to complete locking of the tooth 110 to the adaptor 120.

FIGs 3A to 3D show a lock 1000 for an excavator wear assembly according to a second embodiment of the invention. Like numerals have been used to describe like components. The lock 1000 shown in FIGs 3A to 3D is very similar to the lock 1000 shown in FIGs 1A to 1D. The main variation is in respect to how the first member 1100 is fastened to the second member 1200.

The retaining member 1130 again has fastening portion 1132. However, the fastening portion 1132 is in the form of threaded, fastening bore, which extends into the retaining member 1130 .of the retaining member 1130.

The fastener 1300 is in the form of a bolt as is known in the art. The bolt has a external, threaded end to allow the bolt to fit into the fastening portion 1132 and a head which sits within the fastener recess 240.

In order to secure the first member 100 to the second member 1200, the retaining member 1130 is slid into the retaining recess 1230. The fastener 1300 is then screwed onto the threaded, fastening bore 130 which causes the fastener 1300 to bear against the shoulder 1241 of the fastening recess 1240. The continued rotation of the fastener 1300 subsequently causes the first bearing face 1131 of the retaining member 1130 to bear up against the second bearing face 1231 of the retaining recess 1230. Once this occurs, rotation of the fastener 1300 is ceased and the plug 1400 is located within the fastener 1300.

It would be appreciated by a person skilled in the art that the lock of the second embodiment could replace the lock of the first embodiment and visa-versa. Further, it would also be appreciated by a person skilled in the art how the lock of the second embodiment would be used in order to secure a tooth to an adaptor using the description provided for FIGs 2A to 2C.

The retaining recess 1230 and retaining member 1130 being conical in shape provides the advantage that there is low friction when the first member 1100 and second member 1200 are released from each other especially if fines are located between the retaining recess 1230 and retaining member 1130.

In this specification, the terms "comprise", "comprises", "comprising" or similar terms are intended to mean a non-exclusive inclusion, such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

Throughout the specification, the aim has been to describe the invention without limiting the invention to any one embodiment or specific collection of features. Persons skilled in the relevant art may realize variations from the specific embodiments that will nonetheless fall within the scope of the invention.

It will be appreciated that various other changes and modifications may be made to the embodiment described without departing from the spirit and scope of the invention.

Claims

CLAIMS:

1. A lock for an excavator wear assembly, the lock comprising:

wherein the at least one first bearing face and the at least one second bearing face are inclined with respect to a longitudinal axis that extends through the first member and the second member when the retaining, member of the first member is received within the retaining recess of the second member.

2. The lock of claim 1 wherein a fastener is releaseably fastened to the retaining member to secure the first member to the second member.

3. The lock of claim 2 wherein a fastener recess is located within the second member to locate the fastener.

4. The lock of any one the preceding claims wherein a fastening portion forms part of the retaining member.

5. The lock of claim 4 wherein the fastening portion is located externally on the retaining member.

6. The lock of claim 4 wherein the fastening portion is located internally within the retaining member.

7. The lock of claim 5 wherein the fastening portion is in the form of a fastening end.

8. The lock of claim 7 wherein the fastening end is at least partially threaded.

9. The lock of claim 6 wherein the fastening portion may be in the form of a fastening bore.

10. The lock of claim 9 wherein the fastening bore is at least partially threaded.

11. The lock of any one of the preceding claims wherein the retaining recess and the retaining member are typically complementary in shape.

12. The lock of any one of the preceding claims wherein the retaining member is substantially frusto-conical in shape.

13. The lock of any one of the preceding claims wherein the retaining recess is frusto-conical in shape.

14. The lock of any one of the preceding claims wherein there is only a single first bearing face.

15. The lock of any one of the preceding claims wherein there is only a single second bearing face.

16. The lock of any one of the preceding claims wherein the number of first bearing faces is equal to the number of second bearihg faces.

17. The lock of any one of the preceding claims wherein the majority of the at least first bearing face bears against the majority of the at least second bearing face.

18. An excavator wear assembly comprising:

the retaining recess adapted to releasably receivee the retaining member of the first member so that the first bearing face bears against the second bearing face; wherein the at least one first bearing face and the at least one second bearing face are inclined with respect to a longitudinal axis that extends through the first member and the second member when the retaining member of the first member is received within the retaining recess of the second member.