Technical Field

The present disclosure relates to a tooth assembly for attachment to digging devices. The disclosure has application for waterborne digging devices such as dredgers and is herein described in that context. However, it is to be appreciated that the disclosure has broader application for example in land based digging devices such as front end loaders, and is therefore not limited to that application.

Backqround

Excavation teeth are provided on the digging edge of various digging devices including dredging cutter heads and the buckets of front end loaders. Each excavation tooth is formed from an assembly of a number of components including one or more tooth members. This is to enable detachment of worn or broken teeth from the digging device and replacement with a new tooth which saves having to replace a much larger component such as a front end loader bucket or a dredging head. Further, where the excavation tooth is formed from more than one tooth members, it is possible to avoid having to discard the entire tooth when only a part of the tooth, in particular the ground engaging part of the tooth, is worn or broken.

Various types of tooth assemblies and components thereof are known. However, it is always desirable to design new excavation tooth assemblies and parts thereof. Summary of the Disclosure

The present disclosure relates to improvements in tooth assemblies for attachment to digging devices.

According to one embodiment, the present disclosure provides a tooth assembly for attachment to a digging device, the assembly comprising: a tooth member having a forward ground engaging portion and a rearward mounting portion, the mounting portion having a recess which defines an internal surface, the mounting portion configured to be received onto a mounting body provided on the digging device when the tooth member is in an assembled condition with the device; and

a lock assembly for locking the tooth member to the digging device, the lock assembly comprising:

an insert member configured to be at least partly received in the recess of the tooth member when the tooth assembly is in its assembled condition, the insert member comprising a body having an aperture extending through the body along an aperture axis and a surface portion that engages a portion of the internal surface of the tooth member when the insert member is received in the recess; and

a pin member configured to be inserted into the recess of the tooth member and the aperture of the insert member to receive the insert member over the pin member when the tooth assembly is in its assembled condition, the lock assembly operable to apply a load on the insert member in the direction of the insert member's aperture axis, and wherein

at least one of the engaging surface portions of the insert member body and the internal surface of the tooth member are inclined relative to the insert member's aperture axis such that when an axial load is applied to the insert member the tooth member is biased onto the mounting body in a direction transverse to that load.

According to another embodiment, the present disclosure provides method of attaching a tooth member to a digging device, the method comprising: positioning a rearward mounting portion of the tooth member onto a mounting body provided on the digging device, the mounting portion having a recess defining an internal surface;

positioning an insert member of a lock assembly, comprising a body having an aperture extending through the body along an aperture axis, in the recess of the tooth member such that a surface portion of the insert member's body engages a portion of the internal surface of the tooth member;

inserting a pin member of the lock assembly into the recess of the tooth member and the aperture of the insert member so as to receive the insert member over the pin member; and

operating the lock assembly to apply a load on the insert member in the direction of the insert member's aperture axis, whereby the tooth member is biased onto the mounting body in a direction transverse to that load.

Brief Description of the Drawings

Figure 1 is an exploded perspective view of a tooth assembly for attachment to a digging device according to an embodiment of the present disclosure.

Figure 2 is a top perspective view of the tooth assembly of Figure 1 in an assembled condition.

Figure 3 is a side view of the tooth assembly of Figure 1 in an assembled condition.

Figure 4 is a side view in cross-section of the tooth assembly of Figure 1 in an assembled condition. Figure 5 is a bottom view of the tooth assembly of Figure 1 in an assembled condition.

Figure 6 is a top perspective view of a tooth member of the tooth assembly of Figure 1. Figure 7 is a rear elevated view of the tooth member of Figure 6.

Figure 8 is a rear view from underneath of the tooth member of Figure 6.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings, which form a part thereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other 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 tooth assembly for attachment to a digging device, the assembly comprising: a tooth member having a forward ground engaging portion and a rearward mounting portion, the mounting portion having a recess which defines an internal surface, the mounting portion configured to be received onto a mounting body provided on the digging device when the tooth member is in an assembled condition with the device; and

a lock assembly for locking the tooth member to the digging device, the lock assembly comprising:

an insert member configured to be at least partly received in the recess of the tooth member when the tooth assembly is in its assembled condition, the insert member comprising a body having an aperture extending through the body along an aperture axis and a surface portion that engages a portion of the internal surface of the tooth member when the insert member is received in the recess; and

a pin member configured to be inserted into the recess of the tooth member and the aperture of the insert member to receive the insert member over the pin member when the tooth assembly is in its assembled condition, the lock assembly operable to apply a load on the insert member in the direction of the insert member's aperture axis, and wherein at least one of the engaging surface portions of the insert member body and the internal surface of the tooth member are inclined relative to the insert member's aperture axis such that when an axial load is applied to the insert member the tooth member is biased onto the mounting body in a direction transverse to that load. Advantageously, because the inclined surface(s) of the insert member and/or the tooth member biases the mounting portion of the tooth member onto the mounting body under the axial load applied to the insert member by the lock assembly, looseness in the mounting of the tooth member to the mounting body can be 'taken-up' by operating the lock assembly to applied this load to the insert member. Such looseness can occur during use of the digging device for example because of wear of components of the tooth assembly and the mounting surfaces and if not taken-up can result in a loss of operational efficiency of the digging device and potentially the tooth member coming away from the digging device.

In an embodiment, both of the engaging surface portions of the insert member body and the internal surface of the tooth member are inclined relative to the insert member's aperture axis.

In an embodiment, the lock assembly is configured so that application of a rotational force to the pin member applies the axial load to the insert member.

In an embodiment, the engaging surface portion of the insert member engages a rear surface portion of the internal surface defined by the recess of the tooth member, in the assembled condition.

In an embodiment, the mounting portion comprises a leg and the recess extends into leg of the tooth member from a top surface of the leg along a recess axis, the recess axis being parallel to aperture axis of the insert member in the assembled condition.

In an embodiment, the engaging surface portion of the internal surface of the tooth member engaged by the insert member in the assembled condition is inclined relative to the recess axis.

In an embodiment, the body of the insert member has a top surface and a bottom surface, the aperture of the insert member extending between the top and bottom surfaces and wherein the engaging surface portion surface of the insert member is a rear surface of the body that extends between the top and bottom surfaces.

In an embodiment, the body of the insert member narrows as it extends from the top surface to the bottom surface. In an embodiment, an opposed front surface to the engaging surface portion of the body of the insert member is also inclined relative to the aperture axis.

Advantageously, this enables the insert member to be used in the assembled condition in either of two orientations which means that if one of the inclined surfaces of the insert member has become overly worn, the insert member can be turned 180° and remain in use.

In an embodiment, both the opposed front and rear surfaces of the insert member are inclined towards each other as they extend from the top surface to the bottom surface.

In an embodiment, the mounting portion comprises a leg and the recess comprises an aperture extending through the leg of the tooth member.

In an embodiment, the pin member is configured to extend through the aperture of the insert member in the assembled condition.

In an embodiment, the lock assembly also comprises a tightening member that in the assembled condition couples to the pin member on the other side of the insert member to the recess of the tooth member for tightening the engagement of the engaging surface portions of the insert member and the tooth member.

In an embodiment, application of a rotational force to the tightening member applies the axial load to the insert member.

In an embodiment, the pin member has a head portion and wherein, in the assembled condition, the insert member and the tooth member are clamped between the head portion of the pin member and the tightening member.

In an embodiment, at least a portion of the pin member is threaded and configured to engage at least a portion of the aperture in the insert member which is threaded.

In an embodiment, at least a portion of the pin member is threaded and configured to engage at least a portion of an aperture through the tightening member which is threaded.

In an embodiment, the tooth assembly also comprises the mounting body which is the mounting body configured to be attached to the digging device in the assembled condition.

In an embodiment, the mounting body has an aperture extending therethrough which is axially aligned with the aperture through the insert member when in the assembled condition. In an embodiment, the pin member extends through the mounting body aperture in the assembled condition.

In an embodiment, the pin member has a head portion and the mounting body, the tooth member and the insert member are clamped between the head portion of the pin member and the tightening member in the assembled condition.

In an embodiment, the mounting portion of the tooth member is received over at least one mounting surface on the mounting body, and wherein the aperture axis of the insert member is arranged transverse to each mounting surface when the tooth assembly is in its assembled condition.

Disclosed in some embodiments is a method of attaching a tooth member to a digging device, the method comprising: positioning a rearward mounting portion of the tooth member onto a mounting body provided on the digging device, the mounting portion having a recess defining an internal surface;

positioning an insert member of a lock assembly, comprising a body having an aperture extending through the body along an aperture axis, in the recess of the tooth member such that a surface portion of the insert member's body engages a portion of the internal surface of the tooth member;

inserting a pin member of the lock assembly into the recess of the tooth member and the aperture of the insert member so as to receive the insert member over the pin member; and

operating the lock assembly to apply a load on the insert member in the direction of the insert member's aperture axis, whereby the tooth member is biased onto the mounting body in a direction transverse to that load.

In an embodiment, the pin member is inserted into the recess of the tooth member and the insert member is subsequently placed over the pin member so as to insert the pin member into the aperture of the insert member.

In an embodiment, the insert member is inserted into the recess and the pin member is subsequently inserted into the recess of the tooth member and the aperture of the insert member.

Referring now to Figures 1 - 8, a tooth assembly 10 for attachment to a digging device, according to an embodiment of the present disclosure, is shown. The tooth assembly according to the embodiment shown in the Figures, is particularly suitable for attachment to and use with a dredging cutter head. However, tooth assemblies according to other embodiments of the present disclosure and having similar features to the tooth assembly shown in the Figures could be used with other digging devices such as the buckets of front end loaders.

The tooth assembly 10 comprises a tooth member 11 , and a lock assembly 13 for locking the tooth member to the digging device in an assembled condition. The tooth assembly 10 in the embodiment shown in the Figures also comprises a mounting body in the form of a holder 14 which, when the tooth assembly 10 is in the assembled condition, the tooth member 1 1 is mounted to. The holder 14 is attached to the digging device, for example by welding and provides mounting surfaces over which the tooth member 1 1 is received when mounted to the holder 14. In other embodiments, the mounting body may be integrally formed with the digging device. In further embodiments, the tooth assembly does not comprise a mounting body but rather is directly mounted to the digging device.

The holder 14 extends between first and second ends 20, 21 , the first end 20 configured to be attached to the digging device. The tooth member 11 mounts to the holder 14 from the second end 21. The holder 14 has a channel 22 in an upper surface 23 and an aperture 24 extending through the holder 14 from the upper surface to the lower surface 25. The aperture 24 opens in the upper surface 23 in the channel 22 and to a cavity 26 formed in the lower surface 25. The holder 14 narrows towards its first end 20 to form a lip portion 27. The tooth member 11 comprises a forward ground engaging portion in the form of a forward projecting tip 30 and a rearward mounting portion 31 comprising first and second spaced apart legs 32, 33. The first leg 32 extends rearwardly along a longitudinal axis and has a rounded lower surface 34 which is shaped to fit within the channel 22 of the holder 14 when the tooth member 11 is mounted to the holder 14 in the assembled condition. The first leg 32 has a recess forming an aperture 35 that extends through the leg from the leg's upper surface 37 to its lower surface 34 along a recess axis to define an internal surface 36. The aperture 35 is generally rectangular in shape and is longer in the direction of the first leg's longitudinal axis. The front and rear surfaces 36a, 36b of the internal surface defined by the aperture 35 are inclined towards the recess axis and towards each other as they extend from the leg's upper surface 37 to the lower surface 34. Thus, the length of the aperture 35 narrows as it extends from the upper surface 37 to the lower surface 34.

The forward projecting tip 30 extends along an axis that is at an angle to the longitudinal axis of the first leg 32 towards a leading side 38 of the tooth member 1 1. The first leg 32 also has a raised portion 39 in its upper surface that 36 extends from a region of the first leg that is forward of the aperture 35 around to and extending substantially along the leading side 38 of the tooth member 1 1. By "leading side" it is understood that this refers to the side of the tooth member which, in use, would lead into engagement with the ground. The purpose of this raised portion 39 will be described below. The second leg 33 of the tooth member 1 1 is shorter in length than the first leg 32 and is shaped to fit over the lower surface of the lip portion 27 of the holder 14 in the assembled condition. However, in other embodiments, the second leg could be of a similar length to the first leg and also provided with a similar aperture to the first leg.

The lock assembly 13 comprises an insert member 12, a pin member 50, shown in the form of a bolt, and a tightening member 51 , shown in the form of a nut.

The insert member 12 comprises a blocky body 40 which is shaped generally as a trapezoidal prism. The body 40 has top and bottom surfaces 41 , 42 with an aperture 43 extending through the body along an aperture axis between the top and bottom surfaces. The body 40 also has front and rear surfaces 44, 45 and opposed side surfaces 46, 47. The front and rear surfaces 44, 45 are inclined relative to the aperture axis and toward each other as they each extend from the top surface 41 to the bottom surface 42. As a result, the top surface 41 is longer than the bottom surface 42. The side surfaces 46, 47 are generally parallel to each other and perpendicular to both of the top and bottom surfaces 41 , 42.

The insert member 12 is configured to be received, at least partly, in the aperture 35 formed in the first leg 32 of the tooth member 1 1 when the tooth assembly 10 is in its assembled condition. When so received in the aperture 35, the rear surface 45 of the insert member's body 12 engages the rear surface 36a of the insert surface 36 defined by the aperture 35. The rear surface 36a defined by the aperture 35 is inclined to the aperture axis of the insert member's aperture 43 at the same angle as the rear surface 45 of the insert member's body 40 so as to facilitate maximum engagement between the surfaces. This shaping also enables the insert member's rear surface to slide over the rear surface 36a of the tooth member's aperture 35 (the purpose of which will be described in further detail below). The height of the insert member 12 is approximately the same as that of the tooth member's aperture 35. However, the tooth member's aperture 35 is longer than the insert member 12 at both the top and bottom respectively. As a result, when the insert member 12 is fully received in the tooth member's aperture 35, some clearance space remains at the forward end of the aperture. Advantageously, this enables a tool to be inserted into the aperture to lever out the insert member 12, when disassembling the tooth assembly 10.

The pin member 50 comprises a shank 52 which is shaped to be inserted, in the assembled condition, through the apertures 24, 35 and 43 of the holder 14, tooth member 1 1 and the insert member 12 respectively so that the insert member 12 is received over the pin member 50. When so inserted, the shank 52 projects out of the other end of the aperture 43 of the insert member 12 to the end from which it is inserted.

The pin member also comprises a head portion 53 at one end of the shank 52. The head portion 53, in the assembled condition, engages (via a washer 54) a surface of the holder 14 defined by the cavity 26 in the holder's lower surface 25. A substantial portion of the shank 52, including, in the embodiment shown in the Figures, the opposed end of the shank to the end where the head portion 53 is located, is threaded. The threaded portion of the shank 52 is configured to engage the threaded aperture 54 of the tightening member 51 in the assembled condition. As shown in Figure 4, in this assembled condition, the tightening member 51 engages (via a washer 55) the top surface 41 of the insert member body 40.

Each of the head portion 53 of the pin member 50 and the tightening member 51 have side facets 56, 57 for respective engagement by a suitable tool to apply a rotational force to the pin member and/or the tightening member in order to operate the lock assembly

13 to lock the tooth member 11 to the digging device.

To bring the tooth assembly 10 into its assembled condition, the tooth member 1 1 is first mounted to the holder 4 so as to mount it to the digging device. This involves sliding the lower surface 34 of the tooth member's first leg 32 into the channel 22 in the upper surface 23 of the holder 14 and the tooth member's second leg 33 over the lip portion 27 of the holder so that the lip portion is received between the tooth member's legs 32, 33. With the tooth member 11 in this position, the tooth member's substantially larger aperture 35 will be positioned over the aperture 24 of the holder 14.

The insert member 12 is then inserted into the tooth member's aperture 35 with the insert member's aperture 43 substantially axially aligned with the aperture 24 of the holder

14 (and also parallel to the tooth member's aperture axis) and the shank 52 of the pin member 50 subsequently inserted into and through the aligned apertures 24, 43 of the holder and the insert member from underneath the holder 14. Alternatively, the shank 52 of the pin member 50 is first inserted into and through the aperture 24 in the holder and aperture 35 in the tooth member and the insert member 12 subsequently placed over the pin member's shank 52 so as to result in the insert member 12 being received in the tooth member's aperture 35 and the apertures of the insert member and the holder 43, 24 being axially aligned. In both embodiments, the tightening member 51 is then mounted to the shank of 52 of the pin member that is projecting beyond the insert member 52 by engagement of respective threaded portions. As a result, the tooth assembly 10 is loosely assembled with the rear surface 45 of the insert member's body 40 in loose engagement with the rear surface 36b of the internal surface 36 in the tooth member 11 defined by the aperture 35.

To finalise assembly of the tooth assembly 10 into its assembly condition, using suitable tools to engage the side facets 56, 57 of the head portion 53 of the pin member and the tightening member 51 , counter rotational forces are applied to opposed ends of the pin member 50 to rotate the pin member and/or the tightening member 51. This causes the tightening member to translate over the shank 52 of the pin member towards the pin member's head portion 53. As this occurs, the head portion 53 engages (via washer 54) the cavity 26 surface in the holder 14 and the tightening member 51 engages (via washer 55) the insert member 12, applying a load on the insert member in the axial direction of the insert member's aperture. As a result, the insert member 12 also translates over the shank 52 of the pin member. This moves the insert member 12 further into the aperture 35 in the tooth member 1 1 in the direction of the insert member's aperture axis, increasing the area of engagement of the rear surface 45 of the insert member's body 40 with the rear surface 36b of the internal surface 36 in the tooth member 1 1 defined by the aperture 35. When the insert member 12 is in firm engagement with the internal surface 36 of the tooth member 1 1 , an axial load can be continued to be applied to the insert member 12 by application of rotational loads to the pin member and/or tightening member. Because the engaging surfaces 45, 36a of the insert member and the tooth member are inclined relative to the aperture axis of the insert member, which is fixed relative to the holder by the pin member, the axial load applied to the insert member applies a biasing force on the tooth member 11 rearwardly in the direction of the longitudinal axis of the first tooth member's leg (ie. biasing the tooth member onto the holder tranverse to the axial load applied to the insert member).

Thus, by the application of the above described forces, the legs 32, 33 of the tooth member 11 may be caused to translate over their respective mounting surfaces on the holder 14 (ie. the channel 22 and the lower surface of the lip portion 27). The movement of the tooth member 11 onto the holder 14 in this fashion continues until a web surface 60 of the tooth member's mounting portion 31 that extends between the first and second legs 32, 33 engages an edge 61 of the lip portion 27 of the holder 14. The application of rotational forces to the pin member 50 and/or tightening member 51 may continue to tighten up engagement (via washers 54, 55) of the pin member head portion 53 with the holder 14 and the tightening member with the insert member 12. The tooth assembly 10 is now in its assembled condition with the tooth member 1 1 locked to the digging device and ready for use. In this assembled condition, the holder 14, tooth member 1 1 and insert member 12 are tightly clamped between the head portion 53 of the pin member 50 and the tightening member 51. Disassembly of the tooth assembly 10, for example when it becomes necessary to replace the tooth member 11 on the digging device, comprises the reverse of the above described process.

Advantageously, the tooth assembly 10 according to the embodiment shown and described in relation to the Figures can be adjusted to 'take-up' wear that occurs between the assembled components during use, in particular the wear that occurs between the tooth member 11 and the holder 14. This involves the same process of tightening up the tooth assembly as described above with respect to the process of bringing the assembly into its assembled condition. That is, using suitable tools to engage the side facets 56, 57 of the head portion 53 of the pin member and the tightening member 51 , counter rotational forces are applied to opposed ends of the pin member 50 to rotate the pin member and/or the tightening member 51. As described above, this results in a force being applied to the insert member 12 in the direction of its aperture axis, which in turn biases the tooth member 1 onto the holder 14. This biasing force can cause the legs 32, 33 of the tooth member 1 1 to translate over their respective mounting surfaces on the holder 14 to take up looseness due to wear between the engaging surfaces between the tooth member and the holder.

As illustrated in Figures 2 - 5, when the tooth assembly 10 is in its assembled condition, the head portion 53 of the pin member 50 is located within the cavity 26 in the holder 14. This protects the head portion 53 during use from wear and erosion which, if it occurred, could make the head portion 53 difficult to grip with the tool when taking up wear or disassembling the tool assembly. Similarly, the tightening member 51 is positioned substantially below the height off the raised portion 39 of the tooth member 1 1 , which provides protection against wear and erosion of the tightening member because the raised portion 39 extends along the leading side of the tooth member 1 1. Because both the front and rear surfaces 44, 45 of the insert member's body 40 are inclined relative to the aperture axis, this enables the insert 12 to be used in a 180° rotated orientation with the front surface becoming the rear surface. Advantageously, this enables the insert member to be continued to be used when the rear surface 45 has become overly worn. Although in the embodiment shown in the Figures the front and rear surfaces are inclined towards each other, in other embodiments, the front and rear surfaces could be substantially parallel to each other but inclined relative to the aperture axis. In this embodiment, the insert member 12 would be turned upside down as well as turned 180° to use the 'front surface' to engage the rear surface portion of the internal surface defined by the tooth member aperture. In yet another embodiment, the insert member may have front and rear walls that are substantially parallel to the aperture axis. In this embodiment, the effect of biasing the tooth member onto the holder by applying an axial load to the insert member would still be caused by the inclined rear surface portion of the internal surface defined by the tooth member aperture. In a further embodiment, where the insert member has at least a rear surface of its body inclined relative to the aperture axis, the rear surface portion of the internal surface defined by the tooth member aperture is substantially parallel to the axis of both the tooth member aperture and the insert aperture. The inclined rear surface of the insert member in this embodiment would cause the tooth member to be biased onto the holder when the axial load is applied to the insert member.

In a further embodiment, the tooth assembly may not have the tightening member. Instead, in this embodiment, the aperture of the insert member is threaded for threaded engagement with the shank of the pin member. In this embodiment, rotation of the insert member is limited when at least partly received in the aperture of the tooth member by abutment of the sides of the insert member with the sides of the tooth member aperture. Accordingly, when a rotational force is applied to the pin member, a load is applied to the insert member in the direction of its aperture axis (and the axis of the shank of the pin member).

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.