WO2015010159A1

WO2015010159A1 - A lock for an excavation tooth assembly

Info

Publication number: WO2015010159A1
Application number: PCT/AU2014/000748
Authority: WO
Inventors: Mark James Wild; Dylan Toth
Original assignee: Bradken Uk Limited
Priority date: 2013-07-23
Filing date: 2014-07-23
Publication date: 2015-01-29

Abstract

A lock for retaining first and second tooth members of an excavation tooth assembly in an assembled condition, the lock comprising: a body extending along a longitudinal axis between first and second ends and having a surface located towards the first end, the surface extending transversely to the longitudinal axis; an engagement member that is coupled to and movable with respect to the body; and a resilient member coupling the engagement member to the body, wherein the engagement member has a transmitter portion defining a surface that overlaps the transverse surface of the body to enable axial forces on the Sock to be transmitted between the body and the engagement member.

Description

... 3 ....

A LOCK FOR AN EXCAVATION TOOTH ASSEMBLY

TECHNICAL FIELD

The disclosure herein relates to excavation tooth assemblies, locks for use in excavation tooth assemblies and methods for locking tooth members in an assembled condition. The

disclosure has application in land based digging equipment and is herein described in that context. However, It is to be appreciated that the disclosure has broader application for example in waterborne excavation equipment such as dredgers, and is therefore not limited to a single application.

BACKGROUND

Excavation teeth are provided on the digging edge of various pieces of digging equipment such as the buckets of front end loaders. Each excavation tooth is formed of a number of components, commonly a point, an adapter and a lock. The adapter is typically fitted to the excavation equipment and the point fits over, and protects the adapter and is retained in place by the lock. In some instances one or more intermediate parts may be also included between the point and the adapter. For ease of description It is to be understood that, unless the context requires otherwise, th term "adapter" used in this specification includes both the adapter arranged to be fitted to the excavation equipment or, if one or more intermediate parts are provided, to that intermediate part{s) or to the combination of the adapter and the intermediate part(s).

The reason that the excavation tooth is formed of a number of parts is to avoid having to discard the entire tooth when only parts of the tooth, in particular the ground engaging part of the tooth (i.e. the point) is worn or broken. As these components need to be regularly mounted and removed, a strong yet non-permanent locking assembly is required that can hold the adaptor in place under heavy load, be inserted and removed in-situ and does not cause damage to the underlying adaptor to which it is mounted.

An elastomeric component may be used within a locking assembly to provide an element of compressibility between essentially rigid, steel components. However, the elastomeric component is much more prone to wear than the steel members, especially In exposed, potentially dirty conditions. As the elastomer material deteriorates the components of a locking assembly can begin to drift and at a critical juncture over-ride can occur where the primary components of the locking assembly become so misaligned that the functionality of the locking assembly is lost. Override can also lead to components of the lock jamming in the space between the tooth members in which it is located, making them difficult and time consuming to remove.

Various types of locks, point and adapters are industriall used. However, it is always desirable to design new assemblies and parts thereof that can provide improvements during usable service-life.

SUMMARY OF THE DISCLOSURE

The present disclosure relates to improvements in relation to excavation tooth assemblies and in particu!ar to locks for use in excavation tooth assemblies. The present disclosure also relates to methods of locking first and second tooth members of an excavation tooth assembly in an assembled condition.

According to a embodiment of the present disclosure, there is provided a lock for retaining first and second tooth members of an excavation tooth assembly in an assembled condition, the lock comprising:

a body extending along a longitudinal axis between first and second ends and having a surface located towards the first end, the surface extending transversely to the longitudinal axis;

an engagement member that is coupled to and movable with respect to the body; and a resilient member coupling the engagement member to the body,

wherein the engagement member has a transmitter portion defining a surface that overlaps the transverse surface of the body to enable axial forces on the lock to be transmitted between the body and the engagement member.

According to another embodiment of the present disclosure, there is provided a lock for retaining first and second tooth members of an excavation tooth assembly in an assembled condition, the lock comprising:

a body extending along a longitudinal axis between first and second ends;

an engagement member that is coupled to and movable with respect to the body; and a resilient member coupling th engagement member to the body,

wherein the body comprises a cavity in which the resilient member is at least partially received, the cavity defining a longitudinally extending wall, the body also comprising a recess that extends into the wail. According ίο another embodiment of the present disclosure, there is provided a method of locking first and second tooth members of an excavation tooth assembly in an assembled condition, the method comprising inserting_, a lock into a locking space of the tooth assembly whereby a body of the lock engages a surface of the locking space and an engagement member of the lock engages another surface of the locking space and a resilient member of the lock biases the body and the engagement member into their engagements with surfaces of the locking space, wherein during insertion of the lock a surface of the body that extends transverse to the direction of insertion and a surface of a transmitter portion of the engagement member overlap to enable axial forces on the lock to be transmitted between the body and the engagement member.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will no be described below, wherein like reference numerals indicate similar parts throughout the several views. Embodiments are illustrated by wa of example, and not by way of limitation, with reference to the accompanying drawings, in which;

Figure 1A and 1 B are perspective views of an excavation tooth assembly, illustrating the locking pin of Figure 8 before and after insertion into a locking space formed between first and second tooth members of the assembly to hold them in their assembled condition;

Figure 1C is a plan view of the locking space between the first and second tooth members of Figures 1A and 1 B;

Figure 2A is a perspective view of the lock and the point of Figures 1 A and 18, illustrating the position of the lock with respect to the point when the lock has been inserted into the locking space;

Figure 2B is a partial elevated end view of the lock and the point of Figure 2A;

Figure 3 is a right side view of a lock according to one embodiment;

Figure 4 is an isometric view of the lock of Figure 3, illustrating the alignment of the components of the lock;

Figures 5A to 5D are a front view, left side view, rear isometric view and right side view of the body of the lock assembly of Figure 3, respectively;

Figure 6 is an isometric view of an engagement member of the lock of Figure 3 in isolation;

Figure 7A is an end view of the engagement member of Figure 8 assembled with a resilient member of the lock;

Figure 7B is an end view of the engagement member of Figure 6 in isolation;

Figure 8 is a right side vie of the engagement member of Figure 8;

Figure 9 is a front isometric vie of a body of the lock of Figure 3 in isolation; Figures 10A and 1GB are an exploded right side and isometric view, respectively, of another embodiment of a lock (which is shown in Figure 1);

Figures 1 1 A to 11 D are an isometric rear view, right side view, front view and left side view of a body of the iocs of Figures 10A and 10B, respectively;

Figure 11 E is a partial view of the lock of Figures 1GA and 10B with respect to the point of Figures 1A and I B as the lock is being inserted into the locking space;

Figure 12A is an isometric view of an engagement member of the lock of Figure 10A in isolation;

Figure 12B is an elevated end view of the engagement member of Figure 12A assembled with a resilient member (shown in outline};

Figure 12C is an end view of the engagement member of Figure 12A;

Figure 12D is a right side view of the engagement member of Figure 12A;

Figure 13 is an isometric view of a body of the lock of Figure 10A in isolation;

Figure 14A and 148 are right side perspective views of an engagement member and a body of a lock according to a further embodiment;

Figure 14C is a left side perspective view of the engagement membe of Figure 14A;

Figure 15A and 15B are right side perspective views of an engagement member and a body of a lock according to a further embodiment; and

Figure 5C is a left side perspective vie of the engagement member of Figure 15A.

DESCRIPTION OF EMBODIMENTS in the following detailed description, reference is made to the accompanying drawings, which form a part thereof, in the drawings, similar symbols typically identify sim lar components, unless context dictates otherwise. The Illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Othe embodiments may be utilised, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

Disclosed in some embodiments is a lock for retaining first and second tooth members of an excavation tooth assembly in an assembled condition, the Sock comprising:

a body extending along a longitudinal axis between first and second ends and having a surface located towards the first end, the surface extending transversely to the longitudinal axis; an engagement member that is coupled to and movable with respect to the body; and a resilient member coupling the engagement member to the body,

wherein the engagement member has a transmitter portion defining a surface thai overlaps the transverse surface of the body to enable axial forces on the lock to be transmitted between the body and the engagement member.

The movement between the engagement member and the body provides for the effective working range of the lock. During use, the resilient member can wear as a result of material fatigue, and by contamination from exposure to a harsh working environment. This can loosen the connection between the engagement member and the body, and provides a potential for the aforementioned over-ride condition. An important factor in causing an over-ride condition is that the ioad on the engagement member is applied as a shear or tensile load to the resilient member. As the resilient member will, by necessity, have a lower tensile strength than either the

engagement member or the body components of the lock, this loading into the resilient member can misalign or even detach the components of the lock from one another, allowing the over-ride to occur.

By overlapping the surface of the transmitter portion with the transversely extending surface of the body, loads applied to the engagement member continue to be reacted by the body through the transversely extending surface, whether directly or indirectly, even when the resilient member is worn. As a result, the possibility of over-ride of the lock components occurring during use is minimised. Furthermore, the transmitter portion and the transversely extending surface are configured so that the relative movement between the engagement member and the body during normal service of the lock is not hampered by the overlap.

The overlap between the transmitter portion and the transversely extending surface also minimises the possibility of over-ride occurring during installation of the lock in the assembly of the first and second tooth members. Installation of the lock involves inserting the lock into a locking space formed between the first and second tooth members when they are brought info their assembled condition. The lock is hammered into the locking space by hammering on the body of the lock in the longitudinal direction of the body. The lock has a fight fit in the locking space in order to function as a lock and hold the first tooth member to the second tooth member. More specifically, the engagement member has a tight friction fit with at least one surface of the locking space and the body has a tight friction fit with at least one surface of the locking space. During installation, because the hammering force is being applied to the bod and the engagement member is in a tight fit with at least one surface of the locking space, this can lead to high shear or tensile loads being applied to the resilient member. As a result, even if the resilient member is not worn, the hammering on the body of the lock during instaliaiion can result in failure of the resilient member and/or dislocation and over-ride of the body with respect the engagement member. The overlap between the transmitter portion surface of the engagement member and the transversely extending surface of the body, however,, enables the hammering force on the body during instaliaiion to be transmitted directly into the engagement member. This minimises the loading on the resilient member and hence the likelihood of over-ride occurring. in some embodiments, the overlapping surfaces of the body and the engagement member are configured to relieve axial loading on the resilient member.

In some embodiments, the overlapping transmitter portion surface extends transversely to the longitudinal axis of the body. in some embodiments, the overlapping transmitter portion surface has a length transverse to the longitudinal axis of the body which is at least 30%, preferably at least 50% of the length of the transverse surface of the body in the transverse direction.

In some embodiments, the lock has an extended condition and a compressed condition in which the engagement member is moved towards the body from its position in the extended condition and wherein the transmitter portion surface, at least in part, overlaps the transverse surface of the body when the lock is in its compressed condition.

In some embodiments, the transmitter portion surface, at least in part, overlaps the transverse surface of the body when the lock is in its extended condition.

In some embodiments, the transmitter portion surface is in contact with the traverse surface of the body. in some embodiments, the transmitter portion surface is located at an end of the engagement member.

In some embodiments, the transmitter portion surface slides over the transverse surface of the body when the engagement member moves with respect to the body. In some embodiments, the body has a cavity in which the resilient member is received, the transverse surface of the body forming one of the surfaces of the cavity.

In some embodiments, the body has a first shoulder portion located towards the first end of the body and a second shoulder portion located towards the second of the body, the cavity extending longitudinally between the first and second shoulder portions.

In some embodiments, the transverse surface of the body is an inner surface of the first shoulder portion.

In some embodiments, the body has a further surface extending transversely to the longitudinal axis that is located towards the second end of the body.

In some embodiments, the further transverse surface is an inner surface of the second shoulder portion.

In some embodiments, the transverse surface located towards the first end of the body faces the further transverse surface located towards the second end of the body.

In some embodiments, the body has a longitudinally extending wail that defines a rear surface of the cavity that faces in the direction in. which the engagement member is configured to move with respect to the body.

In some embodiments, the transverse surface is substantially orthogonal to the rear surface of the cavity, in some embodiments, the body has a recess which is configured to receive at least part of the transmitter portion and/or a portion of the resilient member when the lock is in its compressed condition.

In some embodiments, the recess extends into the wall from an opening in the rear surface of the cavity.

In some embodiments, the recess tapers as if extends from its opening in the rear surface of the ca vity

In some embodiments, the recess extends through the wall to open in an outer surface of the body. - g ....

In some embodiments, an inner surface of the recess forms part of the transverse surface of the body which the transmitter portion is configured to overlap.

In some embodiments, the recess is of greater size than the transmitter portion to enable the transmitter portion to fit within the recess, in some embodiments, the recess is iocated towards the first end of the lock body.

In some embodiments, the recess extends along the wail for a substantial lengt of the cavity.

In some embodiments, the body has a further recess which is configured to receive at least a part of the transmitter portion and/or a portion of the resilient member when the lock s in its compressed condition, the further recess Iocated towards the second end of the lock body.

In some embodiments, the body has a web extending between the first and second shoulder portions thai defines an inner side surface of the cavity.

In some embodiments, the transverse surface is substantially orthogonal to the inner side surface of the cavity.

In some embodiments, the web has a slot formed therein. in some embodiments, the engagement member extends along a longitudinal axis between first and second ends,

In some embodiments, the longitudinal axis of the engagement member is aligned with the longitudinal axis of the body.

In some embodiments, the engagement member has an engagement portion for engaging the first and/or second tooth members when retaining them in their assembled condition, the engagement portion extending longitudinally and defining an outer surface facing away from the body.

In some embodiments, the engagement portion has a length which is approximately the same as the length of the cavity of the body.

In some embodiments, the outer surface of the engagement portion is convexly curved. ... ....

In some embodiments, the outer surface of the engagement portion is curved

symmetrically across its length.

In some embodiments, the outer surface of the engagement portion curves from its second end to a mid region.

In some embodiments, the outer surface is shaped with decreasing curvature towards its mid region.

In some embodiments, the engagement portion has curved shoulder portions at one or both ends.

In some embodiments, the engagement member comprises a pocket for receiving at least a portion of the resilient member.

In some embodiments, the engagement member comprises a base extending from an inner surface of the engagement portion and between first and second ends of the engagement member, the base defining an inner surface of the pocket.

In some embodiments, the transmitter portion of the engagement member extends over and engages a surface of the resilient member.

In some embodiments, the transmitter portion is tapered as it extends towards the body. In some embodiments, the transmitter portion comprises a projection from the engagement portion.

In some embodiments, the projection projects from the engagement portion awa from the direction In which the outer face of the engagement portion faces.

In some embodiments, a side of the projection defines an end surface of the engagement member, and the transmitter portion surface that overlaps with the transverse surface of the body.

In some embodiments, the side of the projection is substantially planar.

In some embodiments, the transmitter portion is formed as an extension of the engagement portion. In some embodiments, the transmitter portion surface that is configured to overlap the transverse surface of the body is formed as an extension of the outer surface of the engagement portion.

In some embodiments, the transmitter portion is located towards the first end of the engagement member.

In some embodiments, the transmitter portion extends the length of the engagement portion.

In some embodiments, the engagement member comprises a further transmitter portion, the transmitter portion and the further transmitter portion located towards either end of the engagement member.

In some embodiments, the engagement member comprises a bar extending between the projections, the bar spaced from the engagement portion.

Disclosed in some embodiments is a Sock for retaining first and second tooth members of an excavation tooth assembly in an assembled condition, the lock comprising;

a body extending along a longitudinal axis between first and second ends;

wherein the body comprises a cavity in which the resilient member is at least partially received, the cavity defining a longitudinally extending wall, the body also comprising a recess that extends into the wall.

The recess allows for an increased range of movement between the engagement member and the body by providing a dearance space Into which a portion of the engagement member can be received upon movement with respect to the body and/or a portion of the resilient member can expand into upon movement of the engagement member with respect to the body. By providing this clearance, the risk of failure of the lock due to overloading of the resilient member and/or the engagement member is reduced.

In some embodiments, the Sock has an extended condition and a compressed condition in which the engagement member is moved towards the body from its position in the extended condition and wherein when the lock is in its compressed condition, part of the engagement member and/or a portion of the resilient member is received in the recess. ... 1 1 ...

In some embodiments, the body has a surface located towards the first end, the surface extending transversely to the longitudinal axis and the engagement member has a transmitter portion, the transmitter portion defining a surface configured: to, at ieast In part, overlap the transverse surface of the body to enable axial forces on the lock to be transmitted between the body and the engagement member.

In some embodiments, the lock is configured to enable the transmitter portion to be receivable in the recess upon movement of the engagement member towards the body.

In some embodiments, the recess extends into the wall from: an opening in a rear surface of the cavity defined by the wall.

In some embodiments, the recess tapers as it extends from its opening in the rear surface of the cavity

In some embodiments, the recess extends through the wall to open in an outer surface of the body.

In some embodiments, an inner surface of the recess forms part of the transverse surface which the transmitter portion surface is configured to overlap.

In some embodiments, the recess is of greater size than the projection to enable the projection to fit within the recess.

In some embodiments, the recess is located towards the first end of the lock body.

In some embodiments, the recess extends along the wail for a substantial length of the cavity.

In some embodiments, the body has a further recess which extends Into the wall of the cavity, the further recess located towards the second end of the lock body.

In some embodiments, the bod has a chamfered surface at least one of the first and second ends of the body, the chamfered surface defining a guide surface for riding over at least a portion of the assembled tooth members as the lock is inserted into a locking space between the tooth members to guide the lock into its correct positioning within the locking space In some embodiments, the chamfered surface extending across a major portion of the end of the body.

In some embodiments, the chamfered surface tapers from the rear of the body towards the front of the body.

In some embodiments, the chamfered surface is at an angle of about 30-70° , preferably about 50⁰ to the rear surface of the body.

Disclosed in some embodiments is an excavation tooth assembly comprising a first tooth member and a second tooth member configured to be assembled together in an assembled condition, and a lock configured to be inserted into a locking space of the tooth assembly to hold the tooth members in their assembled condition, the lock comprising a lock according to any one of the above described embodiments.

Disclosed in some embodiments is a method of locking first and second tooth members of an excavation tooth assembly in an assembled condition, the method comprising inserting a lock into a locking space of the tooth assembly whereby a body of the lock engages a surface of the locking space and an engagement member of the lock engages another surface of the locking space and a resilient member of the lock biases the body and the engagement member into their engagements with surfaces of the locking space, wherein during insertion of the lock a surface of the body that extends transverse to the direction of insertion and a surface of a transmitter portion of the engagement member overlap to enable axial forces on the lock to be transmitted between the body and the engagement member.

In some embodiments, insertion of the lock into the locking space causes the lock to adopt a compressed condition in which the transverse surface of the body overlaps the transmitter portion surface of the engagement member.

The overlapping of the transverse surface and the transmitter portion surface enables forces applied to the lock during insertion and use of the excavation tooth assembly, to be transmitted between the engagement member and the body and away from the resilient member. This reduces the likelihood of overloading and potential failure of the resilient member.

Referring now to Figures 1A-1 C and 2 A and 28, there is shown an excavation tooth assembly 10 comprising a first tooth member 12 and a second tooth member 14 in an assembled condition and a lock 800 for Socking the first and second tooth members 12, 14 in their assembled condition. The first tooth member 12 is in the form of a point having a leading edge which, in use, engages the ground. The second tooth member 14 is in the form of an adapter that is configured to be attached to the digging edge of a piece of digging equipment such as an excavation bucket or a dredge cutterhead. As shown in Figure 2A_: the point tooth member 12 has a socket 18 that receives a nose portion of the adapter when the tooth members 12, 4 are brought into their assembled condition. in this assembled condition, the tooth members 12, 14 form a locking space 8 between them (see Figure 1C) into which the lock 800 is inserted to lock the tooth members in their assembled condition. Figures 2A and 2B show the position of the lock 800 with respect to the point tooth member 12 when it is inserted into the locking space 18,

Although in Figures 1A-2B the lock 800 is shown being inserted into a locking space 18 that is formed to the side of the assembled tooth members 12, 14, it is to be understood that the lock 800 according to any of the embodiments described in further detail below may be used with tooth members having different configurations for the lock space. For example, the tooth members may have a locking space that extends transversely through the first and second tooth members. It is also to be understood, that although the lock 800 is shown in Figures 1.A-2B being used to Seek a first tooth member to a second tooth member, embodiments of the lock may be used to lock a first tooth member to an intermediate member between the first and second tooth members and/or to lock the intermediate tooth member to the second tooth member.

Further, although in Figures 1A-2B, the lock 800 according to embodiments shown and described beiow in relation to Figures 10A-13 is shown as being part, of the illustrative embodiment for the excavation tooth assembly 10, the locks according to other embodiments of the present disclosure may be incorporated into the same or similar excavation tooth assemblies.

Each of these embodiments of the lock will now be described in further detail.

Referring firstly to Figures 3-9, a lock 00 is illustrated and comprises a body 110, an engagement member 130, and a resilient member 150. The lock 100 is elongate and is Inserted into the locking space 16 formed between the tooth members 12, 14 in a direction which generally corresponds with the longitudinal axis of the lock 100. The lock 100 is shaped to enable its insertion and removal from either end of the locking space 18. The engagement member 130 Is assembled with the body 1 10 by coupling the engagement member 130 to the resilient member 150 and coupling the resilient member 150 to the body. The lock 100 components are assembled such that the engagement member 130 is movable with respect to the body 1 10 against a bias provided by the resilient member 150. When the lock 100 is inserted into the locking space 16 the engagement, member 30 Is pressed in towards the body 1 0, compressing the resilient member 150. In this compressed state, the resilient member provides an outward bias to the body 110 and the engagement member 130 away from each other. This enables the lock 100 to take up wear on the body 110, the engagement member 130 and surfaces of the point and adapter tooth members 12, 14.

The body 1 10 extends along a longitudinal axis between first and second ends 112, 114. The body 110 has a first substantially planar surface 113 at its first end 112 that faces outwardly from the lock and which provides a contact surface through which loads can be applied to the lock 100 to drive it into the locking space 16 with a tool such as a hammer or the like. To remove the lock 100 from the locking space 18 (to disassemble the excavation tooth assembly), a force is applied to the same surface 1 13 using the same or similar tool to drive the lock oui of the locking space 16. The body 110 is also provided with, at its, second end 1 14 a similar second

substantially planar surface 115 that Is outwardly facing and which can also be used to drive the lock 00 into and out of the locking space 16. In this manner the lock 100 can be driven into and out of a locking space 18 in either direction, providing increased flexibility in confined working conditions.

Turning to Figures 5A to 5D, the body 1 0 is shown in isolation from the engagement and resilient members 130, 150 from a number of different perspectives to illustrate various features.

The body 1 10 has a large centra! cavity 120 disposed between first and second shoulder portions 170, 171 at the first 112 and second ends 1 14 respectively of the body 110. The shoulder portions are each provided with tapered and/or rounded external surfaces to assist with insertion and removal of the lock 100 from the locking space 18. The cavity 120 extends longitudinally a substantial portion of the length of the body 110, and is of a generaliy rectangular configuration. A wall 128 extends longitudinally between the shoulder portions 170, 171 and defines a rear surface 172 of the cavity 20. A web 122 also extends longitudinally between the shoulder portions 170, 171 and away from the rear surface 172 of the cavity 120 defined by the wall 128. The web 122 defines an inner side surface 173 of the cavity 120 that is at approximately 90° to the rear surface. Each shoulder portion 170, 171 also has an inner surface 125, 127 that defines a respective end surface of the cavity 120 and which are transverse to the longitudinal axis of the body 10. The shoulder inne surfaces 125, 127 generally face towards each other. In the embodiment shown in Figures 5A-5D, the shoulder inner surfaces 125, 127 are each disposed at approximately 90" to both the rear surface 1 2 and the inner side surface 173 such that the shoulder inner surfaces are .substantially parallel to one another. However, in other embodiments, the shoulder inner surfaces may diverge or converge towards each other as they extend away from: the rear surface and/or the base surface.

As shown in particular In Figures 5A and 9, the body 110 comprises two recesses that extend into the wail 128 from an opening 1 5 in the rear surface 172; a first recess 124 located towards the first end 112 of the body and a second recess 128 located towards the second end 1 14. The recesses 124, 126 open to the cavity 120 in the body 110, but do not extend entirely through the. wail 128. In some embodiments, as shown in Figure 5A, the body 110 has two recesses 124, 126; however, it is contemplated that in other embodiments the body may have only a single recess or more than two recesses.

The two recesses 124, 128 are located as far away from each other as possible to maximise the area of the rear surface 172 therebetween. This is to provide as large as possible a seating surface for the resilient member 150, when received in the cavity 120 (as will be described in detail below) The recesses 124. 128 have chamfered transition surfaces 178 where they open in the rear surface 172 to provide a smooth surface for the resilient member 150 to seat upon. As the recesses 124, 126 extend into the wall 128 they narrow or taper. Each recess has opposed upper and lower surfaces 180, 181 which converge towards each other as they extend away from the recess opening. Each recess also has opposed side surfaces 182. 183 extending between respective upper and lower surfaces that also converge towards each other as they extend away from the recess opening. The recesses are each configured so that one of their respective upper or lower surfaces forms a continuous surface with the end surface 125, 127 of the shoulder portion 170, 171 located at the respective end of the body 1 0. The recesses 124, 126 are not located centrally on the wall 128, but towards a right side of the body away from the web 122,

As shown in particular in Figure 5C, the body 1 10 has a keying flange 117 extending from a rear surface 190 of the body along its longitudinal axis. The keying flange 1 17 is provided to enable the lock 100 to be correctly oriented when Inserting the lock into the locking space 16. The body 110 also has a lip 118 extending from its rear surface 190 which assists in locating the lock ... I fj ...

100 within the locking space 18 and in particular with respect the point tooth member 12. As with the embodiment shown in Figure 2B, the lip 118 is configured to cooperate with inward projections 191 , 192 on the point tooth member by fitting between them when the lock is inserted into the locking space 18. Rear surface portions 190a,b of the body 110 engage and bear against surfaces 193, 194 of the inward projections of the point toot member when the lock is in the locking space.

Referring now to Figures 8-8, the engagement member 30 is elongate with an

engagement portion 132 that extends between a first 133 and a second end 134 of the

engagement member 130. When the engagement member 130 is assembled with the body 1 10, the engagement portion 132 extends generally in line with the longitudinal axis of the body 110.

The engagement portion 132 defines an outer surface 180 which is convexly curved from the first end 133 to the second end 134 of the engagement portion. When the lock 100 is inserted into the locking space 16. the outer surface 180 of the engagement portion engages a surface of the adapter tooth member 14. In the embodiment shown in Figures 6-8 the curve is symmetrical and extends the length of the engagement member 130, The curvature of the outer surface of the engagement portion 132 increases substantially towards the ends 33, 134 of the engagement portion. This defines curved shoulders 147, 148 which provide lead In surfaces when inserting the lock 00 into the locking space 16. Leading with the first end of the lock body 1 10 and hence also the first end of the engagement member 130, as the lock 100 is inserted into the locking space 18, loads will initially be applied to the engagement member 130 through the curved shoulder 147 at the first end 133 and begin to compressiveiy load the resilient member 150. As this load is being unevenly applied to the engagement member 130, there is a tendency for the second end 134 of the engagement member 130 to be forced away from the body 1 10 which could potentially decouple the engagement member from the resilient member at its second end and/or decouple the engagement member from the body. The convex outer surface of the engagement member's engagement portion minimises this effect and enables a more even loading of the engagement member 130 and the resilient member 150 during insertion. in the embodiment shown in Figures 8-8, the curved shoulders 147, 148 at either end of the engagement portion and the convex curvature of the engagement portio across Its length mean that irrespective of which orientation the lock 100 is inserted, uneven loading of the engagement member and the resilient member as described above is minimised. The engagement member 130 has a base 141 that extends between first and second ends 133, 134 out of the curved inner surface 142 of the engagement portion 132. The base 141 together with the inner surface define a pocket 140 for receiving at least a portion of the resilient member 50. When the lock is assembled the resilient member 50 seats against and is attached to the base 141 and the inner surface 142 of th engagement portion 132. The base 141 overlays the inner side surface 173 defined by the web 122 of the body 1 0,

The engagement member has at its first end 133 a first projection 137 and at its second end 134 a second projection 138. The proieciions 137 and 138 are extensions of the back bone 132 as it curves around in a C-shape form. Each of the projections 137, 138 define an outer end surface 144, 145 that does not taper as it extends along the side of its respective projections 37, 138, As shown in Figure 3 for example, the projections form part of transmitter portions of the engagement member such that when the components of the lock 100 are assembled, the outer end surfaces 144, 145 of the of the engagement member 130 overlap with the inner surfaces of respective shoulder portions of the body 1 10 to enable axial forces on the Sock to be transmitted between the body and the engagement member.

The outer end surfaces 144, 145 of the engagement membe engage the respective inne surfaces 125, 127 of the body shoulder portions 170, 171. When the engagement member 130 moves with respect to the body 110 the outer end surfaces 144, 145 slide along the respective inner surfaces of the body shoulder portions. The lack of tapering of the outer end surfaces 144, 145 provides maximum contact area with the respective inner side walls 125, 127 as the engagement member 130 slides along parallel to the inner side walls. As described above, this overlapping arrangement minimises the hsk of over-ride occurring during installation and use of the lock 100.

The transmitter portions in the form of the projections 137, 138 are smoothly transitioned from the engagement portion 132, with rounded, chamfered edges and each taper down to a rounded tip 137a, 138a as they extend away from the engagement portion 132. The tapering of the projections 137, 38 provides a complementary shape to the recesses 124, 126 of the body 110. When the engagement member 130 Is moved in towards the body 110 the projections 137, 138 are received in respective recesses 124, 128. It is noted that because each of the recesses have an internal surface that forms a continuous surface with respective inner surfaces 125, 127 of the shoulder portions 1 0, 171 , the projections 137, 138 can slide seamlessly along these surfaces and into the recess 124, 128 maintaining a constant contact. These respective surfaces of the recesses 124, 126 are not tapered, providing for maximum surface contact with the projection 137, 138 in this region.

The tapering of the projections 37, 138 and of the recesses 124, 128 allows for minor mismatches and tolerance issues without hampering the ability of the lock 100 to function. When two components are co-located with a resilient member, there can be some play in the system. The play in the lock 100 is thus overcome by the oversized entry to each recess 124, 128 (relative to the projections) and the tapering, ensuring that the body 1 10 and the engagement member 130 will align and the projections self locate in respective recesses, in the embodiments shown in Figures 3-9, the resilient member 150 is in the form of an elastomeric block. However, it is to be understood that the resilient member could be In other suitable forms. For example, the resilient member could comprise a spring or a plurality of springs.

The elastomeric block 150, when In location within the lock 100 has only one face exposed, to minimise exposure to the harsh working environment. The remaining sides of the elastomer 150 are co-iocated with the cavity 120 of the body 1 10 and the pocket 140 of the engagement member 130. By surrounding the elastomeric block 150 on opposing sides with the engagement member and the body 110, the two components are movably coupled to one another..

As shown in particular In Figure 7A, the elastomeric block 150 is comprises a channel 152 which provides a geometric feature for locating the elastomeric block 150 along the wail 128 of the cavity 120. The channel 152 may extend the entire length of the elastomer or may comprise a series of channel portions that correspond; to geometric features within the cavity 120 of the body 110.

In some embodiments the geometric form of the elastomeric block 150 can be used to maintain contact between the components. It is also contemplated that the elastomeric block can be over-moulded around the engagement member 130 and the body 110 to adhere the

components of the Sock 100. Alternatively, it i contemplated that an adhesive can be used to maintain engagement between the elastomeric block 150 and the body 110, and the elastomeric block 150 and the engagement member 130.

In one embodiment of the lock 100, the elastomeric biock 150 Is provided with a plurality of holes 57. which extend partially or fully, as illustrated in Figures 3 and 4. through the elastomeric ... 19 ... block 150. The plurality of holes 15? Increases the compressibility of the eiastomeric block 150 once compressed within the confined volume of the locking space 106, the body 110 and the engagement member 130, in combination. The holes 157 thus increase the working range of the lock 100 and provide the necessary compressibility required where an oversized eiastomeric block 150 is employed within the lock 100. in addition, as the elastomer 150 Is compressed, it can expand into the recesses 124, 128 of the body 1 10.

Another embodiment of a lock 800 is illustrated in Figures 0A to 13. The lock 800 has some similar features to the lock 100 of Figures 3-9 and such features are provided with the same reference numbers but substituting the prefix "1" for the prefix "8".

One notable difference between the lock 800 and the lock 100 is that the engagement member 830 only has a single transmitter portion comprising the projection 837 located at the first end 833. Correspondingly, the body 810 only has a single recess 824 extending Into the longitudinal wall 828 from the rear surface 872 that defines the cavity 820 and located towards the first end 812 of the body 810. The recess 824, in the embodiment shown in Figures 3-9, extends through the wall 828 to open in the rear surface 890 of the body 810 as well as in the rear surface 872 of the cavity 820. The components of the lock 800 are also configured such that movement of the engagement member 830 towards the body 810, rather than resulting in the projection 837 being received in the recess 824, causes the resilient member 850 in the form of an eiastomeric block to expand Into the recess.

The engagement member 830 is also shaped whereby its engagement portion 832 does not have a symmetric convexiy curved outer surface across its length. Rather, the engagement portio 832 Is provided with an outer surface 860 that curves convexiy from the second end 834 of the engagement portion 832 to a mid region of the surface providing a taper from the second end 834 to the mid region. From this mid region to the first end 833, the outer surface has little curvature in the longitudinal direction.

These features of the lock 800 mean that it is designed to be inserted into the locking space 16 from one direction, leading with the second end 814/834 of the body 810/engagement member 830. The curved and tapered: shape of the outer surface 880 from the second end 834 to the mid region of the engagement portion 832 eases this insertion. At the leading second end 814 of the body 810, a large chamfered surface 855 is provided on the rear surface 890 of the body 810, The chamfered surface 855 extends across the majority of the second end 814 of the body 810, tapering from the rear surface 890 towards the forward edge 856 of the body 810. The chamfered surface 855 is at an angle of 30-70° , preferably about 50° to the rear surface 890 of the body 810. As shown in Figure 11 E, the chamfered surface 855 provides a ramp or shoulder portion that in addition to defining a guide surface for entry of the lock 800 into the locking space 16, also defines a guide surface which helps to guide insertion of the lock 800 past the second and lower of the inward projections 192 on the point tooth member 12 which in part define the locking space 18 as the lock 800 is hammered into the locking space. This reduces the likelihood of the lock 800 slipping in between the inward projections 191 , 192 and becoming jammed in an incorrect position.

The body 810 of the lock 800 is also provided with a slot 895 in and extending through the web 822. This slot allows for further expansion of the resilient member in the form of the elastomeriG block 150 and enables a greater working range of movement for the engagement member with respect to the body. in another embodiment, it is contemplated that instead of providing two separate

complementary projections 137, 138 and recesses 124, 12 6, a single elongate recess

1324 and a complementary elongate bar 1398 can be provided for the body 1310 and engagement member 1330 respectively, as illustrated in Figures 14A to 14C. The lock 1300 of these Figures also has some similar features to the lock 100 of Figures 3-9 and such features are provided with the same reference numbers but substituting for '13'. The resilient member is not Illustrated in Figures 14A to 14C; however, it is still a necessary component of this embodiment

The engagement member 1330 is provided with a central pocket 1340 to house a resilient member, and once the two components, the engagement member 1330 and the resilient member, are assembled they can be inserted into the body 310. The pocket 1340 can be both enciosed on one side, or cut through the entire engagement member 1330 to thereby provide access to the resilient member from either side of the engagement member 1330.

As referred to above, the engagement member 1330 comprises an elongate bar 1398 that extends longitudinally between the projections 1337, 338 at first and second ends 1333, 1334 of the engagement member. - 2! -

As in the previous embodiment the cavity 1320 is large enough to house both the resilient member and the engagement member 1330, and is located within the body 1310, such that the elongate bar of the engagement member is lined-up with the recess 1324 extending from the cavity 1320 into the wall 1328. Both the bar 1396 and the recess 1324 have smoothed, rounded edges and the entrance to recess 1324 is larger than the widest part of the bar, to that as the bar is moved towards the recess 1324, the two components, 1330 and 1310 locate in relation to one another.

When the engagement member 1330 moves relative to the cavity 1320, the end surfaces 1344, 1345 defined by the projections 1337, 338 travel along the inner end surfaces 1325, 1327 defined by the first and second shoulder portions, respectively. This guides the direction of the movement between the engagement member 1330 and the body 1310, and further provides a beneficial overlap condition between the engagement membe 1330 and the bod 1310, when the lock 300 is inserted into a locking space 18. in yet another embodiment, it is contemplated that the recess 1520 within the body 1510 is of an open form, opening to a side of the lock as illustrated in Figures 15A to 15C. The lock 1500 of these Figures also has some similar features to the lock 100 of Figures 3-9 and such features are provided with the same reference numbers but substituting for Ί 5'. in this embodiment, the engagement member 1530 comprises a single elongate projection 1537 that extends along the longitudinal axis of the engagement member 1530.

The engagement member 1530 has a central pocket 1540 capable of housing a resilient member (not shown), disposed therein. When the engagement member 1530 is moved towards the body 1510, end contact surfaces 1544, 1545 of the projection 1537 travel along respective inner end surfaces 1525, 1527 of the shoulder portion, providing an overlapping condition between the two components. The resilient member is sandwiched therebetween. The projection 1537 is located to the side of the lock 1500 such that when the lock is assembled, the projection 1537 extends over a side of the resilient member. With the inner side surface 1573 of the lock body 810 located on the opposite side of the resilient member, the resilient member is substantially enclosed between the lock body 15 0 and the engagement member 1530. This substantial enclosure of the resilient member in this embodiment offers performance benefits by protecting the resilient member and shielding it from the external environment in which It is employed.

In the claims which follow and in the preceding disclosure, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the present disclosure.

Accordingly, the present disclosure is not to be limited in terms of the particular

embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from Its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled, it is to be understood that this disclosure is not limited to particular methods which can, of course, vary, it is also to be understood that the terminology used herein Is for the purpose of describing particular embodiments only, and is not intended to be limiting.

From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

A lock fo retaining first and second tooth members of an excavation tooth assembly in an assem led condition, the lock comprising:

A lock as claimed in claim 1 , wherein the overlapping surfaces of the body and the engagement member are configured to relieve axial loading on the resilient member.

A lock as claimed in claims 1 or 2_., wherein the overlapping transmitter portion surface extends transversely to the longitudinal axis of the body.

A lock as claimed in any one of the preceding claims, wherein the overlapping transmitter portion surface has a length transverse to the longitudinal axis of the body which is at least 30%, preferably at least 50% of the length of the transverse surface of the body in the transverse direction,

A lock as claimed in any one of the preceding claims, wherein the lock has an extended condition and a compressed condition in which the engagement member is moved towards the body from its position in the extended condition and wherein the transmitter portion surface, at least in part, overlaps the transverse surface of the body when the lock is in its compressed condition,

A lock as claimed in claim 5, wherein the transmitter portion surface, at least in part, overlaps the transverse surface of the body when the lock is in its extended condition.

A lock as claimed in any one of the preceding claims, wherein the transmitter portion surface is in contact with the traverse surface of the body.

8. A lock as claimed in any one of the preceding claims wherein the transmitter portion surface is located at an end of the engagement member.

9. A lock as claimed in any one of the preceding claims, wherein the transmitter portion

surface slides over the transverse surface of the body when the engagement member moves with respect to the body.

10. A lock as claimed in any one of the preceding claims, wherein the body has a cavity in

which the resilient member is received, the transverse surface of the body forming one of the surfaces of the cavity.

11. A lock as claimed in claim 10, wherein the body has a first shoulder portion located towards the first end of the body and a second shoulder portion located towards the second of the body, the cavity extending longitudinally between the first and second shoulder portions.

12. A lock as claimed in claim 11 , wherein the transverse surface of the body is an inner

surface of the first shoulder portion.

13. A lock as claimed in any one of claims 0-12, wherein the body has a further surface

extending transversely to the longitudinal axis that is located towards the second end of the body,

14. A lock as claimed in claim 13 when dependent on claims 8 or 9. wherein the further

transverse surface is an Inner surface of the second shoulder portion.

15. A lock as claimed in claim 13 or 14, wherein the transverse surface located towards the first end of the body faces the further transverse surface located towards the second end of the body,

16. A lock as claimed in any one of claims 10-15. wherein the body has a longitudinally

extending wall that defines a rear surface of the cavity that faces in the direction in which the engagement member is configured to move with respect to the body.

17. A lock as claimed in claim 18, wherein the transverse surface is substantially orthogonal to the rear surface of the cavity.

18. A lock as claimed in claim 16 or 17 when dependent on claim 5, wherein the bod has a recess which is configured to receive at least part of the transmitter portion and/or a portion of the resilient member when the lock is in Its compressed condition.

19. A iock as claimed in claim 18, wherein the recess extends into the wall from an opening in the rear surface of the cavity.

20. A iock as claimed in claim 18 or 1 , wherein the recess tapers as it extends from its

opening in the rear surface of the cavity

21. A iock as claimed in any one of claims 18-20, wherein the recess extends through the wall to open in an outer surface of the body.

22. A iock as claimed in any one of claims 18-21.. wherein an inner surface of the recess forms part of the transverse surface of the body which the transmitter portion surface is configured to overlap.

23. A iock as claimed in any one of claims 18-22, wherein the recess is of greater size than the transmitter portion to enable the transmitter portion to fit within the recess.

24. A iock as claimed in any one of claims 18-23, wherein the recess Is located towards the first end of the iock body.

25. A lock as claimed in any one of claims 18-23, wherein the recess extends along the wall for a substantial length of the cavity,

26. A iock as claimed in any one of claims 18-24, wherein the body has a further recess which is configured to receive at least a part of the transm itter portion and/or a portion of the resilient member when the lock is in its compressed condition, the further recess located towards the second end of the lock body.

27. A iock as claimed in any one of claims 11-23, wherein the body has a web extending

between the first and second shoulder portions that defines an inner side surface of the cavity.

28. A iock as claimed in claim 27, wherein the transverse surface is substantially orthogonal to the inner side surface of the cavity.

29. A lock as claimed in claim 27 or 28, wherein the web has a slot formed therein.

30. A iock as claimed in any one of the preceding claims, wherein the engagement member extends along a longitudinal axis between first and second ends.

31. A lock as claimed in claim 30, wherein the longitudinal axis of the engagement member is aligned with the longitudinal axis of the body.

32. A lock as claimed in claim 30 or 31 , wherein the engagement member has an engagement portion for engaging the first and/o second tooth members when retaining them in their assembled condition, the engagement portion extending longitudinally which defines an outer surface facing away from the body.

33. A lock as claimed in claim 32 when dependent on claim 10, wherein the engagement

portion has a length which is approximately the same as the length of the cavity of the body.

34. A lock as claimed in claim 32 or 33, wherein the outer surface of the engagement portion is convexly curved.

35. A lock as claimed in any one of claims 32-34, wherein the outer surface of the engagement portion is curved symmetrically across its length.

38. A lock as claimed in any one of claims 32-34, wherein the outer surface of the engagement portion curves from its second end to a mid region.

37. A lock as claimed in claim 35 or 38, wherein the outer surface is shaped with decreasing curvature towards its mid region.

38. A lock as claimed any on of claims 32-37, wherein the engagement portion has curved shoulder portions at one or both ends.

39. A lock as claimed in any one of the preceding claims, wherein the engagement member comprises a pocket for receiving at least a portion of the resilient member.

40. A lock as claimed in claim 39 when dependent on claim 32, wherein the engagement

member comprises a base extending from an inner surface of the engagement portion and between first and second ends of the engagement member, the base defining an inner surface of the pocket.

41. A lock as claimed in any one of claims 32-40, wherein the transmitter portion of the

engagement member extends over and engages a surface of the resilient member.

42. A lock as claimed in any one of claims 32-41 , wherein the transmitter portion is tapered as it extends towards the body.

43. A lock as claimed in any one of claims 32-42, wherein the transmitter portion comprises a projection from the engagement portion.

44. A lock as claimed in claim 43, wherein the projection projects from the engagement portion away from the direction in which the outer face of the engagement portion faces.

45. A lock as claimed in claims 43 or 44, wherein a side of the projection defines an end

surface of the engagement member and the transmitter portion surface that overlaps with the transverse surface of the body.

48. A iock as claimed in claim 45, wherein the side of the projection is substantially planar.

47. A lock as claimed in any one claims 32-42, wherein the transmitter portion is formed as an extension of the engagement portion,

48. A iock as claimed in claim 47, wherein the transmitter portion surface that is configured to overlap the transverse surf ace of the body is formed as an extension of the outer surface of the engagement portion..

49. A lock as claimed in any one of claims 30-48, wherein the transmitter portion is located towards the first end of the engagement member.

50. A iock as claimed in any on of claims 30-48, wherein the transmitter portion extends the length of the engagement portion,

51. A lock as claimed in any one of claims 3048, wherein the engagement member comprises a further transmitter portion, the transmitter portion and the further transmitter portion located towards either end of the engagement member,

52. A lock as claimed in claim 51 when dependent on claim 32, wherein the engagement

member comprises a bar extending between the transmitter portions, the bar spaced from the engagement portion.

53. A lock for retaining first and second tooth members of an excavation tooth assembly in an assembled condition, the lock comprising:

a bod extending along a longitudinal axis between first and second ends; an engagement member that is coupled to and movable with respect to the body; and a resilient member coupling the engagement member to the body,

54. A lock as claimed in claim 53, wherein the lock has an extended condition and a

compressed condition in which the engagement member is moved towards the body from its position in the extended condition and wherein when the lock is in its compressed condition, part of the engagement member and/or a portion of the resilient member is received in the recess,

55. A lock as claimed in claim 53 or 54, wherein the body has a surface located towards the first end, the surface extending transversely to the longitudinal axis and the engagement member has a transmitter portion, the transmitter portion defining a surface configured to, at least in part, overlap the transverse surface of the body to enable axial forces on the lock to be transmitted between the body and the engagement member.

56. A lock as claimed in claim 55, wherein the lock is configured to enable the transmitter portion to be receivable in the recess upon movement of the engagement member towards the body.

57. A lock as claimed in any one of claims 53-58, wherein the recess extends into the wall from an opening in a rear surface of the cavity defined by the wail.

58. A Sock as claimed in any one of claims 57, wherein the recess tapers as it extends from its opening in the rear surface of the cavity

59. A lock as claimed in any one of claims 53-58, wherein the recess extends through the wall to ope in an outer surface of the body.

60. A lock as claimed in any one of claims 53-59 when dependent on claim 55, wherein an inner surface of the recess forms part of the transverse surface which the transmitter portion surface is configured to overlap.

81. A lock as claimed in any one of claims 53-80 when dependent on claim 55, wherein the recess is of greater size than the transmitter portion to enable the transmitter portion to fit within the recess,

82. A lock as claimed in any one of claims 53-61 , wherein the recess is located towards the first end of the lock body.

63, A lock as claimed in any one of claims 53-81 , wherein the recess extends along the wail for a substantial length of the cavity,

84. A lock as claimed in any one of claims 53-62.. wherein the body has a further recess which extends into the wall of the cavity, the further recess located towards the second end of the Sock body.

85, A Sock as claimed in any one of the preceding claims, wherein the body has a chamfered surface at least one of the first and second ends of the body, the chamfered surface defining a guide surface for riding over at least a portion of the assembled tooth members as the lock is inserted into a locking space between the tooth members to guide the lock into its correct positioning within the locking space.

66. A lock as claimed in claim 65, wherein the chamfered surface extending across a major portion of the end of the body.

87. A lock as claimed in claim 65 or 86, wherein the chamfered surface tapers from the rear of the body towards the front of the body.

68. A lock as claimed in any one of claims 65-67, wherein the chamfered surface is at an angle of 30-70" , preferably about 50° to the rear surface of the body.

89. An excavation tooth assembly comprising a first tooth member and a second tooth member configured to be assembled together in an assembled condition, and a lock configured to be inserted into a locking space of the tooth assembly to hold the tooth members in their assembled condition, the lock comprising a lock according to any one of the preceding claims.

70. A method of locking first and second tooth members of an excavation tooth assembly in an assembled condition, the method comprising inserting a lock into a locking space of the tooth assembly whereby a body of the lock engages a surface of the locking space and an engagement member of the lock engages another surface of the locking space and a resilient member of the lock biases the body and the engagement member into their engagements with surfaces of the locking space, wherein during insertion of the lock a surface of the body that extends transverse to the direction of insertion and a surface of a transmitter portion of the engagement member overlap to enable axial forces on the lock to be transmitted between the body and the engagement member.

A method as claimed In claim 70, wherein insertion of the lock into the locking space causes the lock to adopt a compressed condition in which the transverse surface of the body overlaps the transmitter portion surface of the engagement member.