WO2023035033A1

WO2023035033A1 - A securing device

Info

Publication number: WO2023035033A1
Application number: PCT/AU2022/051087
Authority: WO
Inventors: Perry John Underwood; Ross James Turner
Original assignee: Hot Spot Holdings Pty Ltd
Priority date: 2021-09-08
Filing date: 2022-09-08
Publication date: 2023-03-16

Abstract

There is disclosed a securing device (10, 70, 80, 116, 132) for releasably securing a first object to a second object. The device comprises a casing (48, 71, 82, 116a-c, 130) configured for being located in a cavity (40, 114, 142) of an assembly of the first and the second objects. A biasing system is housed in the casing. The biasing system provides a biasing force for pressing one end of the device against a bearing surface of the assembly and an opposite end of the device against a further bearing surface of the assembly to retain the first and the second objects against withdrawal from one another when the device is in position in the cavity. The opposite ends of the device are slidable relative to each other against the biasing force. The biasing system typically comprises magnets (54, 56) spaced apart from one another in the casing in a magnetically repelling relationship to one another and arranged for being driven one toward the other to generate the biasing force when the opposite ends of the device are pressed against the bearing surfaces of the assembly. There are also described assemblies secured together by the securing device and methods for use of the device. The securing device is particularly suitable for securing ground engaging tools (G.E.T) or other excavation, dredging, mining, machinery, plant and equipment components together.

Description

A SECURING DEVICE

FIELD OF THE INVENTION

The present invention relates to a securing device for releasably securing a first object to a second object. The invention also relates to an assembly of the first and second objects secured together by a securing device of the invention. Methods for use of a securing device embodied by the invention are also provided.

BACKGROUND OF THE INVENTION

Various securing devices have been described in the art for releasably securing a ground engagement tool (G.E.T) such as a digging or excavation tooth to an adaptor of a mining or excavation bucket (e.g., a dragline bucket). Securing devices for securing a wear plate to such buckets or other equipment have also been described as have securing devices for securing e.g., a tooth to a cutter head of a cutting suction dredger.

A cutting suction dredger is a vessel with a “ladder” at one end for being lowered to the bed of a water body such as that of a harbour, river or estuary for the dredging of mud, silt and rock. A rotatable cutter head is mounted to the end of the ladder and is driven whilst the ladder is pulled from side to side by anchor winches to excavate material. The excavated material is drawn into a suction pipe carried by the ladder and typically pumped to a support barge or other vessel for subsequent disposal. “Spud” poles of the vessel are driven into the bed below the vessel’s hull and the vessel is progressively pushed along in a step-wise fashion by the travel of a spud carriage to reposition the vessel for progression of the dredging, the process being repeated multiple times with repositioning of the spud poles to ultimately dredge a path along the bed of the relevant water body.

Conventionally known such securing devices though have typically involved the use of a mechanical fastener for retention of the securing device in position or holding pins that involve the use of clips or brackets to retain the holding pin(s) in position. A securing device that involves the use of a mechanical fastener is for instance described in International patent publication No. WO 2015/054741. The use of a mechanical fastener can be problematic as dirt and detritus can become caked around the fastener head in use which can make access for removal of the device difficult. The fastener can also become cemented in position and/or incorrect use of tools can result in the head of the fastener being rounded or otherwise damaged which can also make loosening or removal of the fastener problematic. The need to fit and tighten the fastener is also time consuming. Likewise, the use of clips or brackets to retain a holding pin in position can also be cumbersome.

Securing devices which employ permanent magnets for holding the devices in position to secure a tooth or other G.E.T to an adaptor by virtue of magnetic attraction are also described in International patent publication No. WO 2020/237326.

SUMMARY OF THE INVENTION

Broadly, in one or more forms the present disclosure relates to a securing device for securing first and second objects together to form an assembly thereof.

More particularly, in one aspect of the invention there is provided a securing device for releasably securing a first object to a second object, the device comprising: a casing configured for being located in a cavity of an assembly of the first and the second objects; and a biasing system housed in the casing, the biasing system providing biasing force for pressing one end of the device against a bearing surface of the assembly and an opposite end of the device against a further bearing surface of the assembly to retain the first and the second objects against withdrawal from one another when the device is in position in the cavity, the opposite ends of the device being slidable relative to each other against the biasing force.

In at least some embodiments, the bearing surfaces of the assembly comprise a bearing surface of one of the first and second objects and a bearing surface of the other one of the first and second objects. Typically, in such embodiments, the opposite ends of the securing device are opposite longitudinal ends and the device is for blocking withdrawal of the first and the second objects from one another in the lengthwise direction of the device.

Typically, a bearing surface of the at least one end of the device is profiled for abutment with a bearing surface of the corresponding one of the first and second objects whereby the bearing surfaces nest one within the other.

In other embodiments of the invention, the bearing surfaces are bearing surfaces of one of the first and second objects and the opposite ends of the device are opposite longitudinal ends, and the device is for blocking withdrawal of the first and second objects from one another in a cross-wise direction of the device.

In at least some embodiments, at least one of the ends of the device is profiled to mate with the corresponding one of the bearing surfaces.

In at least some embodiments, at least one end of the device has a convex profile and the corresponding bearing surface has a mating concave profile.

Typically, each end of the device is profiled to mate with the corresponding bearing surface.

The biasing system of embodiments as described herein can comprise a pair of spaced apart magnets, wherein the magnets are arranged for being driven one toward the other when the opposite ends of the securing device are pressed against the bearing surfaces of the assembly, and wherein the biasing force is a magnetic force of repulsion generated between the magnets.

Typically, the magnets are spaced apart from each other along the casing in a magnetically repelling relationship to one another.

In at least some embodiments, each of the magnets is disposed in a respective portion of the casing wherein the portions of the casing are slidable relative to one another against the biasing force.

In particularly preferred embodiments, each magnet is respectively encased in a non-magnetically attracted material.

Typically, each of the magnets is disposed in a respective holder, the holders being of essentially non-magnetically attracted material and spacing each of the magnets from a respective side wall of the casing of the device.

Typically, the casing is fabricated from magnetically attracted material. In particularly preferred embodiments, each said holder for the magnets is a cup-shaped holder encasing the respective magnet. In such embodiments, each cupshaped holder has an open end is seated on a respective spacer located between the holder and the corresponding internal end of the casing, the spacer covering the open end of the holder and being formed from an essentially non-magnetically attracted material.

In at least some embodiments, each of the magnets can be magnetically coupled to a corresponding end of the casing.

In at least some embodiments, the ends of a securing device for being pressed against the bearing surfaces are opposite outer ends of the casing.

In other embodiments, the device includes a plunger having an outer said end for being pressed against the corresponding bearing surface, and the plunger is arranged to be pressed into the casing against the biasing force.

In at least some embodiments, the casing of the securing device has a formation for engagement with a removal element for removal of the device from position in the cavity of the assembly. Typically, the formation of the casing comprises a recess in an outer face of the casing for reception of the removal element.

In another aspect of the invention there is provided a securing device for releasably securing a first object to a second object, the device comprising: a casing configured for being located in a cavity formed by the first and the second objects when assembled together; and a biasing system housed in the casing, the biasing system providing biasing force for pressing one end of the device against one of the first and the second objects and an opposite end of the device against the other of the objects to retain the first and the second objects against withdrawal from one another when the device is in position in the cavity, the opposite ends of the device being slidable relative to each other against the biasing force.

In another aspect there is provided an assembly of first and second objects secured together by a securing device embodied by the invention, there being an outwardly facing cavity opening to the exterior of the assembly formed by the first and the second objects and the device being located in the cavity, the device comprising a casing and having opposite ends biased away from one another by biasing force applied from within the casing such that one end of the device is pressed against one of the first and the second objects and the opposite end of the device is pressed against the other of the objects whereby the first and the second objects are retained against withdrawal from one another by the device, the opposite ends of the device being slidable relative to each other against the biasing force.

In some embodiments, the bearing surfaces of the assembly comprise a bearing surface of one of the first and second objects and a bearing surface of the other one of the first and second objects and opposite ends of the device are opposite longitudinal ends, and the device blocks withdrawal of the first and the second objects from one another in the lengthwise direction of the device.

In some such embodiments, one of the first and the second objects has an opening and the other of the objects has a through passageway, and the objects are slidably received one within the other whereby the through passageway overlies the opening to form the cavity in which the securing device is located, the securing device lying in both the opening and the through passageway blocking sliding withdrawal of the first and second objects from one another.

In such embodiments, the casing of the device can lie on a support surface of the one of the first and second objects below the through opening of the other of the objects.

Further, in at least some embodiments of the above type, one of the first and the second objects has a rearwardly extending section with an upstanding rear end portion, the upstanding rear end portion defining the cavity in which the securing device is positioned in combination with a rearwardly facing portion of the other of the objects, the opposite ends of the securing device being pressed against the upstanding end portion and the rearwardly facing portion of the first and the second objects by the biasing force of the securing device whereby the objects are drawn together and retained in abutment with one another by the securing device.

Typically, the one of the first and the second objects has a rearwardly projecting wall and the are other of the objects has a rearwardly directed channel extending from the front of that object to the cavity, the rearwardly projecting wall being fitted in the channel. Typically, a slot formation is defined by a lower portion of the channel and the rearwardly extending section of the one of the first and the second objects is slidably received in the slot formation whereby the slot formation blocks the rearwardly extending section from being lifted in an upward direction.

Typically, the rearwardly extended section has a raised support on which the securing device rests.

In other embodiments of the invention, the bearing surfaces of the assembly are bearing surfaces of one of the first and second objects and the opposite ends of the device are opposite longitudinal ends, and the securing device blocks withdrawal of the first and second objects from one another in a cross-wise direction of the device.

In embodiments of this type, one of the objects can have a channel in which a retainer of the other objects is slidably received and the cavity receiving the securing device can be formed in said one of the objects, wherein the bearing surfaces of the assembly are surfaces of opposite side walls defining the cavity, and the device is located in the cavity adjacent the retainer whereby the device lies across the channel to block sliding withdrawal of the one said object from the retainer, and wherein the reception of the retainer in the channel blocks lifting of the one said object from the other of the objects.

Typically, in such embodiments, the channel is a closed-ended channel and the retainer is located in the channel between the closed end of the channel and the securing device. Most typically, the retainer is located in abutment with the closed end of the channel.

In another aspect of the invention there is provided an assembly of first and second objects secured together by a securing device, the assembly having an outwardly facing cavity opening to the exterior of the assembly and the device being located in the cavity, the device comprising a casing and a biasing system housed in the casing, the biasing system providing biasing force pressing one end of the device against a bearing surface of the assembly and an opposite end of the device against a further bearing surface of the assembly whereby the first and the second objects are retained against withdrawal from one another by the device, the opposite ends of the device being slidable relative to each other against the biasing force. In another aspect of the invention there is provided a method for securing an assembly of a first object and a second object together with a securing device, the method comprising: providing the securing device, the securing device having a casing and a biasing system housed in the casing, the biasing system providing biasing force for pressing one end of the device against a bearing surface the assembly and an opposite end of the device against a further bearing surface of the assembly, the opposite ends of the device being slidable relative to each other against the biasing force; forming the assembly of the first and the second objects wherein one of the objects is slidably received by the other of the objects, the assembly having an outwardly facing cavity opening to the exterior of the assembly; and inserting the securing device into position in the cavity with each said end of the device pressing against the corresponding said bearing surface of the assembly whereby the device blocks sliding withdrawal of the objects from one another.

In another aspect of the invention there is provided a method for securing an assembly of a first object and a second object together with a securing device, the method comprising: providing the securing device, the securing device comprising a casing and having opposite ends biased away from one another by biasing force applied from within the casing for pressing one end of the device against a bearing surface of one of the first and the second objects and an opposite end of the device against a bearing surface of the other of the objects, the opposite ends of the device being slidable relative to each other against the biasing force; forming the assembly of the first and the second objects wherein one of the objects is slidably received by the other of the objects and an outwardly facing cavity opening to the exterior of the assembly is formed by the objects for reception of the securing device; and inserting the securing device into position in the cavity with the opposite ends of the device pressing against the corresponding bearing surfaces of the first and the second objects whereby the device blocks sliding withdrawal of the objects from one another. In at least some embodiments, abutment surfaces of the objects are forced against each other by the force applied to the first and second objects by the opposite ends of the device.

In further aspects, the present disclosure extends to respective of the first and the second objects configured for being secured together as described herein by a securing device embodied by the invention.

The first and second objects can, instance, be machinery components. In at least some embodiments, the components can be pivotable relative to one another when the components are secured together by a securing device as described herein.

Whilst the invention has broad application and may be used for securing together objects that are configured for being assembled together for subsequent use such as excavation, machinery and other components, a securing device in accordance with the present disclosure in at least some forms has particular application to securing a ground engagement tool (G.E.T) or other component (e.g., a wear plate) to an adaptor or other mating part for the G.E.T or other component. In at least some embodiments the G.E.T can be selected from the group consisting of a digging and/or excavation tooth, blade, edge, lip shroud, wing shroud, or wear plate or component for an excavation bucket, dredging bucket, excavation machinery, or for a cutting head such as for a cutting suction dredge, a rotatable mining drum, or other excavation or mining machine or component. The adaptor or other mating part for the G.E.T can be fixed (e.g., be welded), integrally formed or configured for being fitted, connected or welded to a machine or relevant equipment with which the G.E.T component is to be used.

In particularly preferred forms, a securing device of the invention has particular application to securing a tooth or other G.E.T of a cutting head of a cutter suction dredger to an adaptor or other fitting of the cutting head.

In such embodiments, the casing of the securing device may be provided with one or more through apertures which open into the interior of the casing for flow of water into the casing’s interior when the device is submerged in use.

In another aspect of the invention there is provided a ground engagement tool for being secured to an adaptor for the ground engagement tool by a securing device, wherein the ground engagement tool has a bearing surface for engagement with the securing device and at least one abutment surface for abutment with a corresponding surface of the adaptor, and is configured for sliding engagement with the adaptor to form an assembly of the ground engagement tool and the adaptor whereby an outwardly facing cavity opening to the exterior of the assembly is formed by the ground engagement tool and the adaptor for insertion of the securing device into position in the cavity to block sliding withdrawal of the ground engagement tool and adaptor from one another, the bearing surface of the ground engagement tool being located to face in an opposite direction to a bearing surface of the adaptor for forcing the abutment surface of the ground engagement tool against the corresponding surface of the adaptor when the securing device is inserted in position in the cavity with one end of the securing device pressing against the bearing surface of the ground engagement tool and an opposite end of the securing device pressing against the bearing surface of the adaptor.

In another aspect of the invention there is provided an adaptor for a ground engagement tool, wherein the adaptor has a bearing surface for engagement with a securing device for securing the adaptor and the ground engagement tool together, and at least one abutment surface for abutment with a corresponding surface of the tooth, the adaptor being configured for sliding engagement with the ground engagement tool to form an assembly of the adaptor and the ground engagement tool whereby an outwardly facing cavity opening to the exterior of the assembly is formed by the adaptor and the ground engagement tool for insertion of the securing device into position in the cavity to block sliding withdrawal of the adaptor and the ground engagement tool from one another, the bearing surface of the adaptor being located to face in an opposite direction to a bearing surface of the ground engagement tool for forcing the abutment surface of the adaptor against the corresponding surface of the ground engagement tool when the securing device is inserted in position in the cavity with one end of the securing device pressing against the bearing surface of the adaptor and an opposite end of the securing device pressing against the bearing surface of the ground engagement tool.

Advantageously, one or more embodiments of a securing device in accordance with the present invention can allow for the first and second objects to be secured together quickly without the need for mechanical fasteners to be tightened in order for the device to be retained in position in the cavity of the assembly. Typically, the securing device can be pressed into position in the cavity of the assembly by the palm of a hand and/or be levered into position using a pry bar or other lever bar, thereby avoiding the need to hammer the device into position with the associated risk of eye and other injury arising from hardened metal chips flying off the hardened face of the hammer or device casing as can occur with prior art securing systems. Advantageously also, embodiments of securing devices as described herein do not require the tightening or loosening of any fasteners to locate or remove the device from position within the cavity of the assembly, and may be readily and quickly removed from the cavity with the use of a simple pry bar to allow for separation of the objects from one another as described herein.

Further, embodiments as described herein have a relatively minimal number of moving parts and so can provide for reduced wear and/or risk of failure.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers, integers or steps.

Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the invention as it existed in Australia or elsewhere before the priority date of this application.

The features and advantages of the present invention will become further apparent from the following detailed description of exemplary embodiments of the invention together with the accompanying drawings. In at least some embodiments, components or features that are common to them may be identified by the same numbering for ease of description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1 is an isometric view of an assembly embodied by the invention of a tooth and adaptor of a rotatable cutting head of a cutter suction dredger;

Figure 2 is an exploded view of the assembly of Fig. 1; Figure 3 is an isometric view of the adaptor of Fig. 1;

Figure 4 is a plan view of the adaptor of Fig. 1;

Figure 5 is a side view of the adaptor of Fig. 1;

Figure 6 is a side view of the assembly of Fig. 1 illustrating the embodiment of the securing device shown located in position;

Figure 7 is a plan view of another adaptor for use with a securing device of the type shown in Figs 1 and 2;

Figure 8 is an exploded view of the securing device of Fig. 1;

Figure 9 is an exploded view of another securing device embodied by the invention;

Figure 10 is a diagrammatic side view of another securing device embodied by the invention;

Figure 11 is an isometric view of the securing device of Fig. 9;

Figures 12and 13 are front and rear views of another securing device embodied by the invention;

Figure 14 is an exploded view of an assembly including the securing device of Fig. 12;

Figure 15 shows front and rear isometric views of the tooth of Fig. 14;

Figure 16 shows front and rear isometric views of the adaptor of Fig. 14;

Figure 17 is an isometric view of the assembly of Fig. 14 showing the securing device in position in the assembly;

Figure 18 is an exploded view of another securing device embodied by the invention; Figure 19 is a side view of a pry bar for removal of the securing device from the assembly of Fig. 14;

Figure 20 is a front perspective view of a further securing device embodied by the invention;

Figure 21 is a rear perspective view of the securing device of Fig. 20;

Figure 22 is a schematic side view of the securing device of Fig. 20;

Figure 23 is a schematic view showing the shape of the cavity of an assembly in which the securing device of Fig. 20 is positioned in use;

Figure 24 is a schematic exploded side view of the securing device of Fig. 20; Figure 25 is a plan view of a rear portion of the casing of the securing device of Fig. 20;

Figure 26 is a partial elevated schematic view of a lip shroud secured to an excavation bucket by the device of Fig. 20;

Figure 27 is a partial schematic plan view of the lip shroud and excavation bucket assembly of Fig. 26;

Figure 28 is a schematic end view of the lip shroud and excavation bucket assembly of Fig. 27;

Figure 29 is a schematic side view of the lip shroud and excavation bucket assembly of Fig. 27;

Figure 30 is a schematic side view of a further securing device embodied by the present invention;

Figure 31 is a schematic plan view of the securing device of Fig. 30;

Figure 32 is a schematic end view of the securing device of Fig. 30.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Whilst not limited thereto, at least some forms of a securing device embodied by the invention are for use in securing excavation teeth to the cutter head of a cutting suction dredge. Such cutter heads commonly comprise a plurality of arms radiating rearwardly from the front end of the cutter head in a spirally directed fashion. Adaptors for fitting the teeth to the cutter head are spaced apart from each other along the respective arms. Although the adaptors can be integrally formed with the cutter head, in other forms the adaptors may be welded or otherwise secured thereto such as by mechanical fasteners or fastening systems. An assembly 10 of a digging/excavation tooth 12 (also known as a point) secured to an adaptor 14 of a cutter head of a cutting suction dredger by a securing device 16 embodied by the invention is illustrated in Fig. 1. For the purposes of present description, the adaptor 14 is shown as having a squared rear end 18. However, it will be understood that the rear of the adaptor may be integrally formed with the cutter head or otherwise configured for being mounted or welded in position to the cutter head. The tooth 12 shown in Fig. 1 comprises a generally wedge-shaped excavation portion 20 that generally tapers in thickness in a rearward to forward direction to a front cutting edge 22. As better shown in Figs. 2 and 3, the tooth also has a rearwardly extending section 24 for being slidably received in the slot formation 26 of the adaptor 14 and which projects backwardly from the excavation portion 20. The rearwardly extending portion 24 is in the form of an elongate plate member having an upstanding rear end portion consisting of a post 28 and a raised support 30 shaped as a cradle on which the securing device rests in use as discussed further below. The slot formation comprises the bottom portion of a channel indicated by the numeral 32 which extends from the front to the rear of the adaptor 14.

To assemble the adaptor 14 and the tooth 12, the rearwardly directed plate member 24 of the tooth is inserted into the slot formation of the adaptor and slid rearwardly along the adaptor until the rearwardly projecting wall 34 protruding from the excavation portion of the tooth is fitted in the channel 32 of the adaptor and the abutment surfaces 36 of the tooth are brought into abutment with the corresponding surfaces 38 of the adaptor. At this point, a cavity 40 in which the securing device 16 is inserted is formed between the post 28 of the tooth and the rearwardly facing portion 42 of the adaptor. When in position in the cavity, one end 43 of the securing device is pressed into direct abutment with a bearing surface 44 of the post and an opposite longitudinal end 46 of securing device is pressed into direct abutment with corresponding surfaces 48 of the rearwardly facing portion 42 of the adaptor by a biasing system of the device as described further below. The location of the securing device in position in turn forces the abutment surfaces 36 and 38 of the tooth and the adaptor against one another. The tooth and the adaptor are therefore retained by the securing device against sliding withdrawal from one another in the lengthwise direction of the securing device. Further, the reception of the rearwardly directed plate member 24 of the tooth in the slot formation 26 of the adaptor in combination with the engagement of the respective abutment surfaces 36 and 38 of the tooth and the adaptor and the fitting of the rearwardly projecting wall 34 of the tooth secures the assembly against lifting of the tooth from the adaptor in an upward direction as well as tortional and transverse forces applied to the tooth in use. As illustrated, the abutment surfaces 36 and 38 are each inclined downwardly at a common angle in the front to rear direction of the tooth and adaptor assembly.

As also shown in Figs 2 and 3, the bearing surfaces 44 and 46 of the tooth post 28 and the rearwardly facing portion 42 of the adaptor are profiled to mate with the corresponding end surfaces of the securing device 16. That is, in the embodiment shown, the opposite ends 43 and 46 of the securing device are convex in profile whilst the bearing surfaces of the tooth and the post are concave in profile such that each end of the securing device nests in the resulting depression formations defined by the corresponding bearing surfaces 44 and 47 of the tooth post and the adaptor, thereby further constraining the securing device against dislodgment from position in the cavity 40 in the assembly of the tooth 12 and adaptor 14. Plan and side views of the adaptor 14 showing the concave profiled bearing surfaces 47 of the adaptor are shown in Figs. 4 and 5, the bearing surfaces 47 of the adaptor being separated by the front to rear channel 32, whilst a diagrammatic side view of the securing device 10 located in position in the cavity of the assembly is shown in Fig. 6. As generally illustrated in Fig. 6, the casing 48 of the securing device rests on the raised cradle support 30 of the rearwardly extending portion of the tooth 12, the bearing surface 50 of the cradle support being concave in the cross-wise direction of the support to accommodate the circumferential wall of the casing. Whilst the width of the slot formation 26 of the adaptor is essentially constant in the forward to rearward direction of the adaptor shown, other embodiments may be provided in which the width of the slot formation tapers along the slot formation as illustrated in Fig. 7 for reception of a correspondingly tapered rearwardly extending portion 24 of an adaptor 14.

An exploded view of the securing device 16 is shown in Fig. 8. The casing 48 of the device comprises CNC machined casing portions 48a and 48b each formed from a magnetically attracted material (e.g., a marine grade magnetically attracted stainless steel). Casing portion 48a is in the form of a hollow barrel having a closed convex profiled end 43 with a planar internal end face, and which opens at an opposite end for reception of the cylindrical section 52 of the other casing portion 48b. Casing portion 48b also has an open end and an opposite closed convex profiled end 46 with a planar internal end face. In the embodiment shown, the casing 48 houses a biasing system comprising magnets 54 and 56 which when the casing is assembled, are spaced apart from each other along within the casing in a magnetically repelling relationship to one another (i.e., N-S, S-N or S-N, N-S). The resulting magnetic force of repulsion between the magnets therefore generates biasing force driving each of the magnets away from one another and thereby also the end portions 48a and 48b of the casing as further described below. Each magnet is snugly received in a corresponding cupshaped holder 58 or 60 of a non-magnetically attracted material (e.g., a plastic or austenitic metal such as an austenitic stainless steel). Each holder 58 or 60 is in turn fitted in corresponding casing portion 48a or 48b such that each magnet is disposed adjacent to, and is magnetically attracted to, the flat internal end face of the corresponding casing portion thereby retaining the magnets in position when the casing portions 58 and 60 are separated. Flux from the magnets is channelled by respective of the casing portions and essentially does not act on the tooth 12 or adaptor 14 to retain the casing 48 of the securing device in position in the cavity 40. The magnets are each secured in their respective holder by an adhesive. The holder 58 has a larger outer diameter due to a thicker circumferential side wall than that of holder 60 due to holder 60 being received in casing end portion 48b the cylindrical end section 52 of which is slidingly received by the other casing portion 48a when the casing 48 is assembled as illustrated in Fig. 2.

As further shown in Fig. 8, the cylindrical section 52 is fluted and is provided with a closed ended channel 62 for reception of a pin 64 in the form of a grub screw of casing portion 48a. The reception of the pin in the channel 62 thereby allows the casing portion 48b to be slidable toward casing portion 48a against the repelling force between the magnets 54 and 56 but not be separated from one another thereby retaining the casing assembly together, the travel of the casing portions 48a and 48b away from one another under the effect of the repelling biasing force being limited by the pin 64 contacting the closed end 62a of the channel 62.

A plurality of small circumferentially spaced through apertures 63 are provided in the outer wall of casing portion 48a of the embodiment of Fig. 8 to allow water to enter the interior of the casing 48 such as when the securing device is submerged during a dredging operation when the securing device is used to secure a tooth to an adaptor of a cutter head of a cutting suction dredger. Likewise, air can also otherwise enter the casing through the apertures. It will be understood that dirt or sludge which may enter the casing via the apertures 63 can locate in respective of the flutes 66 with retention of capacity for the casing portion to be driven against the biasing force provided by magnets 54 and 56 to permit subsequent removal of the securing device and disassembly of the tooth from the adaptor.

In further embodiments, a plurality of longitudinally directed, closed ended channels 62 may be circumferentially spaced apart from one another about the cylindrical section of casing portion 48b for reception of corresponding pins 64 of the casing portion 48a. In other embodiments, the casing portion 48a may not be provided with circumferentially spaced apertures 63 and instead, a circumferential groove may be provided below the rim 68 of the open end of that casing portion for reception of an O-ring or seal (e.g., a lip seal, or a felt or other fibrous seal) for blocking, restricting and/or filtering the entry of water and/or debris into the casing. Such an embodiment is shown in Fig. 9. In this instance, the cylindrical section 52 of the casing portion is not be fluted as in the embodiment of Fig. 8, and the closed ended channel(s) 62 are located and dimensioned so as to not underly the O-ring or seal situated in the circumferential groove 69 in use.

Further to the above and with reference to Fig. 2, the securing device is initially inserted into the cavity 40 with end 43 orientated at a downward angle. With the application of downwardly directed force to the opposite end region of the device (e.g., applied by the palm of a hand), the end 43 is raised upwardly as the casing portion 48b is slidably driven into casing portion 48a against the repelling biasing force of magnets 54 and 56 by virtue of sliding contact of the convex opposite end 46 of the device with the rearwardly facing portion of the adaptor. The opposite ends 43 and 46 of the device are therefore effectively slidably driven toward each other against the biasing force of the magnets allowing the full length of the device to enter the cavity. With the continued application of the downwardly directed force the opposite ends 44 and 46 are brought into alignment with the bearing surfaces 43 and 47 of the tooth and adaptor. As this occurs, the repelling biasing force of the magnets drives the opposite ends of the device away from one another into the concave depressions formed by bearing surfaces 44 and 47, thereby orientating the device in position in the cavity 40 with the casing portion 48a resting on the concave bearing surface in the cradle support 30 and the opposite ends of the device being pressing against the bearing surfaces 44 and 47 of the tooth and adaptor. In some embodiments, a depression may be provided in the rearwardly extending plate member 24 that has a concave profile in the forward to rearward direction to accommodate a bottom portion of the end 43 of the casing 48 when the casing is initially being inserted in the cavity and guide the upward rotation of that end of the casing into alignment with the bearing surface 44 of the tooth post as the opposite end region of the casing is pressed downwardly.

Another embodiment of a securing device 70 in accordance with the invention is shown in Figs. 10 and 11. In this embodiment, the casing 71 has a convex profiled end 43 and comprises a casing portion 71a which threadably mates with casing portion 71b, each of the casing portions 71a and 71b being formed from a magnetically attracted material as in the embodiment of Fig. 2. In contrast to the securing device of Fig. 2, in this embodiment a single magnet holder 72 of a non-magnetically attracted material is received in bore 73 of casing portion 71a and houses magnets 54 and 56. As also shown, a plunger 74 is received by the casing portion 71b. A felt seal indicated by the numeral 76 is provided between the plunger and the casing portion 71a. Magnet 56 is magnetically attracted to the base of the plunger and is slidable along the holder against the repelling biasing force between the magnets when the plunger 74 is depressed or otherwise forced into the casing 74. As will be understood, when the plunger is released, the plunger 74 and magnet 56 are returned from their extended positions to their respective resting position by the repelling biasing force between the magnets 54 and 56. In use, in this embodiment, convex profiled end 43 of the casing 71 and the planar outer end 78 of the plunger are pressed against the corresponding bearing surfaces of a tooth and adaptor to secure the assembly of the tooth and adaptor together as described herein.

A further embodiment of a securing device 80 of the type with a plunger 74 as shown in Figs. 10 and 11 is illustrated in Figs. 12 and 13. In this embodiment, both the end 43 of the casing 82 and the outer end 84 of the plunger have convex profiles for being pressed into abutment with correspondingly profiled bearing surfaces of the tooth and adaptor. In contrast to the embodiment of Figs. 10 and 11 though, the casing 82 of this embodiment is in the form of a unitary body which slidably receives the plunger 74. A felt seal (not shown) is again disposed in an internal circumferential groove of the casing so as to be disposed between the plunger and the casing. Whilst also not shown and similarly to embodiment of Fig. 2, the plunger 74 is retained in the casing 82 by a securing pin in the form of a grub screw that extends from the casing and is received in a longitudinally directed, closed-ended channel of the plunger. Further, rather than having a cylindrical outer face, the casing 74 is faceted with planar side faces indicated by the numeral 84. In at least some embodiments of this type, the opposite side faces of the casing can be inclined in the top to bottom direction of the casing so that the bottom side of the casing is narrower than the upper side of the casing. The use of the securing device 80 for securing an excavation/digging tooth to an adaptor indicated by the numerals 86 and 88 is illustrated with reference to Figs. 14 to 17.

The diagrammatic form of the “tooth” 86 shown in Fig. 14 comprises a through opening 90 in its upper wall 92 which opens into an interior channel 94 of the tooth for reception of the adaptor 88 as illustrated in the assembled form of the tooth and adaptor shown in Fig. 17. The perimeter of the through opening 90 is profiled to generally correspond to the peripheral shape of the securing device 80 and includes a recess formation 96 for insertion of a removal element into a correspondingly located recess formation 98 defined in end 43 of the device to facilitate removal of the device from the tooth and adaptor assembly as described below. Bearing surfaces 100 and 102 of the tooth 86 for abutment with the end 43 of the casing and the outer end 84 of the plunger are provided at opposite ends of the through opening by the wall 104 of the adaptor.

Similarly, the adaptor 88 has a recess 104 defined in its upper face 106 for reception of the securing device. The perimeter of the recess again generally corresponds to the shape of the securing device, and bearing surfaces 108 and 110 of the adaptor are defined at opposite ends of the recess for abutment with the opposite ends 43 and 84 of the securing device as further shown in Fig. 16. As further shown in Fig. 16, a depression 112 having a concave profile in the lengthwise direction of the adaptor is provided in the floor of the adaptor to facilitate location of the securing device in position. When the adaptor 88 is slid into the channel 94 of the tooth the through opening 90 of the tooth overlies the recess 104 of the adaptor thereby forming a cavity indicated by the numeral 114 for location of the securing device 80. Further, bearing surfaces 100 and 108 of the tooth and adaptor are brought into alignment one above the other as are bearing surfaces 102 and 110, each pair of aligned bearing surfaces forming a respective concave formation for reception of the corresponding convex end 43 or 84 of the securing device.

To locate the securing device in position, the device is inserted into the cavity 114 at a downwardly directed angle with a bottom portion of outer end 84 of the plunger received in the concave depression 112 in the floor of the adaptor. With the application of downwardly directed force to opposite end region of the casing 82 (as e.g., may again be applied by the palm of the hand), the plunger 74 is driven into the casing against the repelling biasing force provided by magnets 54 and 56, shortening the length of the device. At the same time, the device is rotated by sliding contact of the end of the plunger with the depression 112 of the adaptor as the casing enters the cavity, thereby directing the device into alignment with the concave formations formed by the aligned bearing surfaces of the tooth and the adaptor. As the casing longitudinally aligns with concave formations the repelling biasing force of the magnets drives the end 84 of the plunger and opposite end 43 of the casing away from one another into pressed contact with each of the corresponding bearing surfaces of the tooth and adaptor so as to be nested therein, thereby orientating the device in position in the cavity 114 and securing the tooth and adaptor together against sliding withdrawal from one another as shown in Fig. 17. As in embodiments as described above, the securing device is therefore wedged in position in the cavity. Also as in embodiments described above, magnetic flux from the magnets 54 and 56 is directed about the magnetically attracted material from which the casing of the device is fabricated such the securing device 80 is retained in position in the cavity by the biasing force of the magnets pressing the opposite ends of the device into abutment with the tooth and adaptor, rather than by magnetic attraction of the device for the tooth or adaptor.

An exploded view of a yet further embodiment of a securing device 116 in accordance with the present invention is illustrated in Fig. 18. This device comprises casing portions 116a and 116c fabricated from a non-magnetically attracted austenitic stainless steel each having a convex end 118 or 120 defining a respective bearing surface for being pressed into abutment with the corresponding bearing surface of the tooth or adaptor as described herein. Each casing portion also comprises a cylindrical section 116a’ and 116c’ for housing magnet 54 or 56 and sliding reception in intermediate casing portion 116b. In contrast to the casing portions 116a and 116c, intermediate casing portion 116b is fabricated from a magnetically attracted austenitic stainless steel or other magnetically attracted steel or alloy having the properties of hardness and rigidity suitable for the intended use of the securing device. As with the embodiment shown in Fig. 8, the cylindrical sections of the casing portions 116a and 116c are each retained in the intermediate casing portion 116b by reception of a respective pin in the form of a grub screw projecting from casing portion 116b into a closed-ended lengthwise directed channel defined in the corresponding cylindrical section 116a or 116c (not shown). Whilst also not shown, a respective O-ring or suitable seal (e.g., a lip seal or felt seal) is seated in a circumferential groove defined in the interior of each end region of the casing portion 116b for sliding engagement with the corresponding end casing portion 116a or 116. As will also be understood, in use of this embodiment, each of the end casing portions is slidably driven into the intermediate casing portion against the repelling biasing force between magnets 54 and 56 as the device in inserted into position between the tooth and the adaptor. The magnets 54 and 56 are each retained in abutment with the internal blind end of the corresponding casing portion 116a or 116b in use by the repelling magnetic force between the magnets although in embodiments as described herein, each magnet 54 and 56 can also be secured in position by a respective internal mechanical fastener (e.g., a screw) passing through the magnet into the relevant internal end face of the casing or plunger as applicable.

Indeed, rather than opposite ends of the casing pressing against the first and second the tooth and the adaptor as in the embodiment of Fig. 18, embodiments of a securing device of the invention may comprise a casing housing repelling magnets 54 and 56 with a respective plunger 74 projecting from opposite ends thereof for being pressed into engagement with the corresponding bearing surfaces of the tooth and adaptor.

Whilst the above embodiments are described in the context of securing a ground engagement tool (G.E.T) such as a digging or excavation tooth to an adaptor of a cutting head of a cutter suction dredger, the invention is not limited thereto and securing devices embodied by the invention have a broad range of applications such as securing a digging or excavation tooth, blade or scraper to an adaptor of an excavation bucket (e.g., a mining drag-line bucket or a digger bucket of a front-end loader, bucket loader, wheel loader, or other machine loader) or other ground engagement equipment and machinery. When fitting a blade or scraper to an excavation bucket or other equipment component, a plurality of securing devices in accordance with the invention may be required, respective of the devices being for location in spaced apart accommodating formations of the blade or scraper for alignment with corresponding adaptors of the bucket or other equipment component. In yet other embodiments, a device in accordance with the instant disclosure can be used to secure wear plate(s) (e.g., commonly comprising a tough and highly wear resistant ceramic or alloy material overlaid on a less dense material such as a mild steel or chromium steel plate) to equipment or a chute, bin, hopper, bucket or other material handling component to protect that component from abrasive material (e.g., rock, ore, minerals or the like) with which it would otherwise come into contact in use. Typically, in such above embodiments, the securing device is fitted into a cavity formed by aligned openings of the blade, scraper, or wear plate and an adaptor or other component to secure the components together in the manner as described herein.

More broadly, the present disclosure extends to the use of securing devices as describe herein for securing articulation hinges, hitches booms gates and boom points together, or to e.g., earth moving and mining equipment or support components, amongst a broad range of other uses.

Thus, whilst securing devices in accordance with the invention may be utilised in submerged settings (e.g., for securing a tooth to a cutter head to a cutting suction dredger) embodiments also find use in land-based settings. Further, whilst a particular form of a securing device as described herein may be provided for use in a submerged setting, it may also be used for securing a G.E.T to a land-based machine or component thereof.

Also, whilst in the exemplified embodiments a single securing device as described herein has been employed in conjunction with a corresponding adaptor, in other embodiments, a plurality of securing devices can be used. For example, one securing device could be located in a cavity a top face of the assembly and another securing device located in a cavity an opposite bottom face of the assembly, or a respective securing device could be located in cavities formed in opposite sides of the assembly. In embodiments having convex opposite end bearing surfaces as described herein, the radius of each of the surfaces will typically be substantially the same. In particularly preferred such embodiments, when the opposite end faces of the device are pressed together in use, the convex curvature of the surfaces essentially form partial outer surfaces of a notional sphere allowing the device to “roll” into and out of the cavity of the relevant assembly during insertion and removal of the device from the cavity.

It will also be understood that whilst in the embodiments described above, repelling magnets have been used to generate the repelling biasing force for pressing each end of the securing device against the bearing surface of the corresponding one of the objects for being secured together by the device, the invention is not limited thereto and other biasing systems and arrangements for driving the opposite ends of the device away from each other may be utilised. For example, the biasing system may comprise one or more compression springs disposed in the casing of the device so that each end of the spring(s) presses against a corresponding internal end face of the casing, whereby the opposite ends of the device are thereby biased away from each other. Coiled compression springs are desired for these types of embodiments but other spring types for biasing the opposite ends of the securing device away from each other can also be used e.g., flat spring steel springs. However, the use of a repelling magnet arrangement can offer advantages over the use of spring(s) to provide the biasing force driving the opposite ends of the device away from one another as described herein such as reduced risk of mechanical failure, corrosion and fouling. Further, whilst springs can fatigue over time with a consequential risk of weakening of the biasing force they apply, the repelling magnetic force of opposed magnets can provide greater reliability.

Any suitable alternative such biasing systems and arrangements can also be employed in a securing device embodied by the invention. For example, in yet other embodiments of the invention, the biasing force can be provided by gas pressure inside the casing rather than employing repelling magnets or a spring arrangement. For instance, in such embodiments, the securing device can comprise one or more valves for enabling the interior of the casing or internal region or portion thereof to be pressurised to a predetermined level whereby the opposite ends of the securing device are forced away from each other for being pressed into abutment with the bearing surfaces of the first and second objects whilst allowing for the ends of the device to be slidable relative to each other against the pressure in the casing as the device is being located or removed from position within the cavity formed by the first and second objects as described herein. The interior of the casing or relevant interior portion or region thereof can be hermetically sealed by any suitable sealing arrangement e.g., by the use of one or more suitable seals such as O-rings, lip seals, and combinations thereof. In alternative forms of such arrangements, the valve(s) can be valve(s) of, or associated with, one or more bladders disposed in the interior of the casing for being inflated via the valve(s) whereby the biasing force is provided by the inflated bladder(s). The valve or valves for pressurising the casing or inflation of the bladder(s) can be mounted to the casing itself or other appropriate location on the securing device, desirably in a position protected from mechanical forces or abrasion in use of the device. The gas with which the bladder(s) is/are filled and/or the interior of the casing is otherwise pressurised can be any appropriate gas such as air or e.g., nitrogen. In instances the securing device is provided with bladder(s) as above described, the bladder(s) may be fabricated from any suitable elastomeric or other material conventionally used in the fabrication of bladders. Further, when bladder(s) are employed in the device it is not necessary for the interior of the casing to be hermetically sealed.

The biasing force applied by the securing device in embodiments exemplified herein acts to retain the assembly together under tension, and in at least some forms the objects/components are retained in abutment with each other whereby wear between the objects/components is taken up by the opposite ends of the securing device being driven away from one another by the biasing force/biasing system of the device.

To remove the securing device from position for separation of the components secured together by the device a lever element can be inserted between one end of the securing device and the relevant component (e.g., the tooth or adaptor as exemplified herein), and be operated to lever the end of the device free for removal of the device from the cavity in which it had been positioned. A lever element in the form of a pry bar 122 is illustrated in Fig. 19. The bar has a handle 124 and an upturned end 126 for engagement with the end region of the casing of the securing device to lever the device free using the heel 128 of the pry bar as a fulcrum. In at least some embodiments, the tooth and/or adaptor may also be configured for allowing access of the pry bar or other lever element to the device. For example, in the embodiment illustrated in Figs. 14 and 17, the tooth is provided with a downwardly inclined recess 96 that is positioned and orientated to align with the recess engagement formation 98 provided in the end 43 of the casing of the securing device 80 for allowing the upturned end of the pry bar to be inserted in recess 98. Once inserted in recess 98, the end 43 of the casing is levered free as with the pry bar as described above. The casing of the device can then be grasped and pulled from the cavity of the tooth and adaptor assembly. Again, it will be understood that in order to remove the securing device from position, the opposite ends of the device are driven toward each other against the applied biasing force of the device as the levered end of device is dislodged, allowing the device to be rotated in the cavity for subsequently being grasped. Alternative engagement formation(s) that may be employed for removal of a securing device include slot(s), ledge(s), protuberance(s) or other suitable formations. In other embodiments, the lever element can be inserted between the e.g., tooth and adaptor to locate under the end of the securing device for levering that end of the device free. For instance, the upturned end 126 of the pry bar 122 can be inserted into the channel 32 of the tooth and adaptor assembly illustrated in Fig. 1 so as to be located under the end 43 of the securing device shown for levering free that end of the device.

Once an end of a securing device has been freed from engagement with its corresponding abutment surface of the e.g., tooth or adaptor, the biasing force of the device drives the opposite ends of the device away from one another to their initial resting positions relative to one another.

Still another securing device 132 embodied by the invention is illustrated in Figs. 20-24. This embodiment is suitable for use in securing ground engaging tools (G.E.T) together by positioning the casing of the securing device to block sliding withdrawal of one G.ET from the other in a cross-wise direction relative to the lengthwise orientation of the securing device, an example of which is illustrated in Figs. 26-29.

As shown in Figs. 20-25, in this embodiment the casing 130 is generally square in transverse cross-section and rectangular in its lengthwise direction, and comprises casing portions 130a and 130b, both of which are fabricated from a magnetically attracted material and which are slidable relative to one another against the biasing system provided by magnets housed in the casing in a magnetically repelling relationship as further described below. More particularly, as shown in Fig. 22, the casing portion 130a comprises an external end 134 and a hollow internal portion 136 that is slidably received by casing portion 130b. The external end 134 of the casing portion 130a has a bearing surface 136 for mating abutment with a correspondingly shaped bearing surface 138 provided by the face of the side wall 140 of the cavity 142 of a ground engagement tool (G.E.T) which in the exemplified embodiment described is a lip shroud 144 for an excavation bucket as generally illustrated in Fig. 23, whereby the sloping prominence 146 of the casing portion 130a is received in a recess 147 defined in the cavity wall 140. Likewise, the opposite external end 146 of the casing portion 130b is configured to mate with the opposite cavity side wall 148 of the lip shroud whereby the protruding internal rib 150 of the lip shroud is received in the transverse recess 152 of the casing, and a bearing surface 154 of the casing is pressed into abutment with the corresponding bearing surface 156 of the wall 148. Figures 20- 21 show the casing portion 130a fully driven into casing portion 130b. Typically though, the magnetic repulsion generated between the magnets in embodiments of this type will be such that the casing portions 130a and 130b are only driven partway together under normal conditions of use of the device. Whilst a lip shroud for an excavation bucket in actual use wraps around the lip of the bucket, only the outer side of the lip shroud is diagrammatically illustrated in the accompanying figures for explanatory purposes. Lip shrouds for excavation buckets are for instance described in International Patent Application WO 2019/191724 as are hinge-type securing devices for securing the shrouds in position around the lip of the bucket, and the entire contents of WO 2019/191724 is incorporated herein in its entirety by cross-reference.

To locate the securing device 132 in position within the cavity 142 of the lip shroud, the device is initially inserted into the cavity at an angle with the rear protuberance 158 of casing portion 130b in front of recess 160 of cavity wall 148. Front casing portion 130a of the device is then driven into casing portion 130b against the repelling biasing force generated by opposed magnets 54 and 56, and is pressed downwardly into the cavity 142. As the casing 130 enters the cavity, the rear protuberance 158 of the casing is driven into the recess 160 and the sloping prominence 146 of the casing portion 130a enters recess 147 defined in the opposite cavity wall in a sliding fit. With subsequent release of the casing portion 130a once the device has been sufficiently lowered into the cavity, the bearing surfaces 136 and 154 of the opposite ends of the casing 130 are driven into pressed into abutment with the respective corresponding bearing surface 138 or 156 of lip shroud 144 by the repelling action of magnets 54 and 56. When located in position, the reception of the prominence 146 in the recess 147 acts to block transverse dislocation of the device, and lifting of the casing portion 130a is blocked by the mating reception of the protruding cavity side wall 140 within the end of that portion of the casing. Similarly, the reception of the protuberance 158 of casing portion 130b in the end recess 160 of the opposite cavity wall blocks lifting of that end of the casing from the cavity as does the reception of transverse rib 150 of cavity side wall 148 in recess 152 of casing portion 130b.

In embodiments of this type, the outer face 153 of the transverse rib can also press against surface 155 defining the base of recess 152 to retain the securing device in position in the assembly in use. In still other embodiments, the casing of the securing device may be dimensioned whereby surface 153 bears against surface 155 in use but surface 154 does not press against surface 156.

An exploded view of the securing device 132 is illustrated in Fig. 24. As shown, the magnets 54 and 56 are each received in a respective corresponding cupshaped holder 149 or 151 formed from a non-magnetically attracted material in a slide fit. A respective spacer 162 comprised of a flat plate or disk that is also formed from a non-magnetically attracted material is located so as to be seated on the base of the cavity 164 or 166 of the corresponding casing portion 130a or 130b. The holder 149 or 151 is received in the respective cavity 164 or 166 of the casing in a press fit so as to be in abutment with the respective spacer 162. The open end of each magnet holder 149 or 151 is thereby closed by the spacer and each of the magnets 54 and 56 are encased by the corresponding spacer and holder. Each magnet 54 and 56 is thereby also spaced from both the surrounding internal wall of the relevant casing portion 130a or 130b and from the inner end 168 or 170 of that casing portion by the non-magnetically attracted material of the respective spacer 162 and holder 149 or 151. The thickness of the peripheral wall of each magnet holder 149 or 151 in the embodiment shown is 1 mm while the base of each holder has a thickness of 0.5 mm. The thickness of each spacer 162 is generally about 2 mm but can, for instance, be in a range of from about 1 mm to about 3 mm or more.

As the magnets are encased in respective holders 149 and 151 formed from non- magnetically attracted material and casing portions 130a and 130b are formed from a magnetically attracted material (e.g., a ferromagnetic material), it is believed that each casing portion 130a or 130b with its corresponding magnet 54 or 56 effectively acts as respective pot magnet, increasing the strength of the magnetic repulsion generated between the magnets 54 and 56, as with the embodiment illustrated in e.g., Figs. 8 and 9. Surprisingly, and as also with the embodiment illustrated in Figs. 8 and 9, magnetic flux from the magnets is believed to be channelled by the respective casing portions and essentially does not act on the lip shroud.

Like the embodiment illustrated in Fig. 8 and Fig. 9, casing portion 130a is slidably retained in casing portion 130b by the reception of pin 171 in the longitudinally directed groove 173 of casing portion 130a. An O-ring or seal 69 is also situated in an internal groove of casing portion 130b to block detritus from entering.

Turning now to Figs. 26-29, the G.E.T lip shroud 144 is diagrammatically shown fitted to the lip of an excavation bucket 172 wherein the shroud 144 is secured in position by location of the securing device 132 in position in the cavity of the lip shroud 144. Neither the sloping prominence 146 nor the recess 147 of cavity wall 140 are shown in Figs. 26-28. The lip shroud 144 has a closed ended dove-shaped channel 174 defined in its underside face that slidably receives a correspondingly profiled retainer 176 welded to the outer face of the excavation bucket in a perpendicular orientation to the bucket lip, preventing the lip shroud 144 from being lifted outwardly from the bucket. As best shown in Fig. 26 and Fig. 27, the lip shroud is slid onto the retainer 176 until the closed end 177 of the blade’s channel 174 lies against one side of the retainer. In this position, the cavity of the blade is located immediately behind the opposite side of the retainer whereby the casing 130 (in this instance both of casing portions 130a and 130b) of the securing device 132 blocks the sliding withdrawal of the lip shroud 144 from the retainer 176 in a cross-wise (i.e., perpendicular) direction with respect to the casing of the securing device.

An embodiment of the invention of the type shown in Figs. 20-29 therefore differs from embodiments as illustrated in e.g., Fig. 1 and Fig. 14 in two main respects. Firstly, the opposite ends of the securing device 132 are pressed into abutment with opposed bearing surfaces of the same component of the lip shroud and excavation bucket assembly and secondly, the components are blocked from being slidably withdrawn from another transversely with respect to the casing of the securing device 132 rather than in the lengthwise/longitudinal direction of the casing. The casing portions 130a and 130b of the securing device illustrated in Figs. 20-29 are therefore sufficiently robust for the expected transverse forces applied to the casing in use of the device.

A variation of the embodiment described above is illustrated in Figs. 30-32 in which the casing portion 130b is instead slidably received by casing portion 130a. The exterior end profile of casing portion 130b is also altered and in this case, the lower end region 178 is rounded to facilitate passage past the protruding internal rib 150 defined in the cavity 142 of the lip shroud when that end of the securing device is pressed downwardly into the cavity when locating the device in position. As also shown in Figs. 31-32, the width of that end of the casing 130b is also reduced (e.g., to 10 mm to 12 mm) compared to the casing portion 130a. As shown, the portion 180 of casing 130b slidably received by casing portion 130a is also cylindrical.

Securing devices as described above can typically be pressed into position by the palm of a hand and/or with the use of a lever element such as a simple pry bar 122 without the need to hammer the device into position in the cavity. By avoiding the use need to use a hammer, the risk of eye or other injury arising from hardened steel chips flying off the face of the hammer or casing of the device is avoided. Advantageously, there are also no mechanical fasteners that require tightening to secure the device in position within the cavity of the assembly or that need to be loosened for removal of the device. As dirt, mud and like detritus can become compacted in and about the cavity and device it can be problematic if it is necessary to tighten or loosen mechanical fasteners in the field.

Again, an embodiment of the type shown in Figs. 20-32 can be removed from its in use position in the cavity of the assembly with the use of a lever element/pry bar 122 by inserting the end of the pry bar into the transverse groove 182 defined in the end of sliding end of casing 130a or 130b, and using the pry bar to levering that end portion of the casing inwardly into the other portion of the casing against the magnetic repulsion generated between magnets 54 and 56 and at the same time, upwardly from the cavity 142.

From the above, it will be understood that in embodiments of the invention the cavity may be provided in one of the objects/components or be formed when the objects/components are assembled together. Further, in embodiments in accordance with the invention, the cavity may be blind cavity (i.e., it has a floor) or be a through passageway.

Any suitable magnetically attracted and non-magnetically attracted materials having the requisite strength, rigidity and robustness for the intended use of the device can be utilised for fabrications of securing devices embodied by the invention. Magnetically attracted and non-magnetically attracted austenitic steels and stainless steels are particularly preferred. A non-magnetically attracted material is one that is not or is essentially non-magnetic or not attracted by a magnetic field, or has essentially no or negligible magnetic properties for the intended purpose and use of the material as described herein.

Preferred non-magnetic austenitic metals e.g., austenitic steels and stainless steels, are those including some or all of the additives selected from the group consisting of manganese (Mn), molybdenum (Mo), chromium (Cr), nickel (Ni), carbon (C) and nitrogen (N). In particularly preferred non-magnetic austenitic steels, the magnetic relative permeability of the steel is less than about 1.001. Most desirably, the nickel content of the steel is less than about 2% w/w.

Further examples of non-magnetically attracted materials besides austenitic stainless steels include aluminium and plastics materials. Magnetically attracted materials include e.g., ferromagnetic materials and steels.

Any suitable permanent magnets may be utilised as the magnets of a securing device described herein, including rare-earth magnets and rare-earth-free magnets. Rare earth magnets can be selected from samarium-cobalt magnets and neodymium (e.g., neodymium, iron and boron) magnets.

Securing devices embodied by the invention therefore have a wide range of applications and are particularly suitable for securing ground engaging tools (G.E.T) together examples of which include for securing an excavation tooth, scrape or blade, to an adaptor of an excavation bucket such as dragline bucket or other mining bucket or the bucket of a bulldozer, front end loader or other such machinery, or for securing G.E.T in the form of a wear plate or component, lip shroud or wing shroud to such excavation buckets or other mining or excavating machinery. However, the invention is not limited thereto and securing devices in accordance with the invention can also be used for other purposes such as for securing a wear plate or wear component to a hopper or other materials handling component (e.g., a bin or chute) or for securing other machinery, plant and equipment components together in the manner described herein for which use of the securing device is suitable or appropriate.

From the above it will be apparent that embodiments of the invention may variously provide one or more of the following advantages.

• A relatively quick and easy way of securing components together as described herein;

• Locating of the securing device in position in the cavity without the need to hammer the device into the cavity, and reducing the potential risk of eye or other injury associated the use of a hammer;

• Securing together of the components without the need for tightening of a mechanical fastener (e.g., a bolt or screw) and thereby, avoiding risk of damage to the fastener and/or the fastener rusting or otherwise becoming stuck or cemented in position;

• Ready removal of the securing device allowing for ease of separation of the secured components from one other;

• Minimisation of wear and thereby maintenance of the device by virtue of the use permanent magnet for providing the repelling biasing force as described above;

• Use of the securing device in a range of different applications; and

• Reusability of the securing device.

Feature(s), integer(s) and/or steps of an embodiment as described above may be implemented in conjunction with feature(s), integer(s) and/or steps of other embodiments, e.g., aspects and/or features of one embodiment may be combined with aspects and/or features of another embodiment to realize yet further embodiments within the scope of the present disclosure, and all such arrangements and embodiments are expressly provided for herein.

Although a number of embodiments of the invention have been described above it will be understood that various modifications and changes may be made thereto without departing from the invention. The embodiments described above are therefore only illustrative and are not to be taken as being limiting or restrictive.

Claims

-32- CLAIMS

1. A securing device for releasably securing a first object to a second object, the device comprising: a casing configured for being located in a cavity of an assembly of the first and the second objects; and a biasing system housed in the casing, the biasing system providing biasing force for pressing one end of the device against a bearing surface of the assembly and an opposite end of the device against a further bearing surface of the assembly to retain the first and the second objects against withdrawal from one another when the device is in position in the cavity, the opposite ends of the device being slidable relative to each other against the biasing force.

2. The device of claim 1, wherein the bearing surfaces of the assembly comprise a bearing surface of one of the first and second objects and a bearing surface of the other one of the first and second objects and the opposite ends of the device are opposite longitudinal ends and the device for blocking withdrawal of the first and the second objects from one another in the lengthwise direction of the device.

3. The device of claim 2, wherein a bearing surface of the at least one end of the device is profiled for abutment with a bearing surface of the corresponding one of the first and second objects whereby the bearing surfaces nest one within the other.

4. The device of claim 1, wherein the bearing surfaces are bearing surfaces of one of the first and second objects and the opposite ends of the device are opposite longitudinal ends, and the device is for blocking withdrawal of the first and second objects from one another in a cross-wise direction of the device.

5. The device of any one of claims 1 to 4, wherein at least one of the ends of the device is profiled to mate with the corresponding one of the bearing surfaces.

6. The device of claim 5, wherein at least one end of the device has a convex profile and the corresponding said bearing surface has a mating concave profile.

7. The device of claim 5, wherein at least one of the ends of the device has at least one recess for receiving a protruding formation of one of the first and the second objects and an opposite end of the device has a prominence for fitting into a recess of the said one of the first and the second objects. -33-

8. The device of any one of claims 5 to 7, wherein each said end of the device is profiled to mate with the corresponding bearing surface.

9. The device of any one of claims 1 to 8, wherein the biasing system comprises a pair of spaced apart magnets, wherein the magnets are arranged for being driven one toward the other when the opposite ends of the securing device are pressed against the bearing surfaces of the assembly, and wherein the biasing force is a magnetic force of repulsion generated between the magnets.

10. The device of claim 9, wherein the magnets are spaced apart from each other along the casing in a magnetically repelling relationship to one another.

11. The device of claim 10, wherein each of the magnets is retained in a respective portion of the casing wherein the portions of the casing are slidable relative to one another against the biasing force.

12. The device of claim 11, wherein the magnets are respectively encased in an essentially non-magnetically attracted material.

13. The device of any one of claims 1 to 12, wherein the casing is fabricated from magnetically attracted material.

14. The device of claim 10 or 11, wherein each of the magnets is disposed in a respective holder, the holders being of an essentially non-magnetically attracted material and spacing each said magnet from a respective surrounding side wall of the casing, and wherein the casing is fabricated from magnetically attracted material.

15. The device of claim 14, wherein each of the magnets is magnetically coupled to a corresponding end of the casing.

16. The device of claim 14, wherein each said holder is cup-shaped and encases the respective said magnet.

17. The device of claim 16, wherein each said cup-shaped holder has an open end and is seated on a respective spacer located between the holder and the corresponding internal end of the casing, the spacer covering the open end of the holder and being formed from an essentially non-magnetically attracted material.

18. The device of any one of claims 1 to 17, wherein the casing has a formation for engagement with an end of a tool for levering of the device from position in the cavity between the first and the second objects for removal of the device.

19. The device of claim 18, wherein the formation of the casing comprises a recess in an outer face of the casing for reception of the tool.

20. The device of any one of claims 1 to 19, wherein the first and the second objects are machinery components.

21. The device of claim 20, wherein one or more of the machinery components are selected from the group consisting of wear plates, wear components, excavation teeth, mining and excavation buckets, excavation bucket lip shrouds and wing shrouds, cutter heads, ground engaging cutting edges, blades and scrapers, and adaptors for the foregoing.

22. The device of any one of claims 1 to 20, wherein the first and second objects are ground engagement tools (G.E.T) or are a and a component for assembly together with a ground engagement tool (G.E.T).

23. The device of claim 22, wherein the component for assembly with the ground engagement tool is an adaptor of an excavation bucket or cutter head for coupling of the ground engagement tool to the excavation bucket or cutter head.

24. An assembly of first and second objects secured together by a securing device, the assembly having an outwardly facing cavity opening to the exterior of the assembly and the device being located in the cavity, the device comprising a casing and a biasing system housed in the casing, the biasing system providing biasing force pressing one end of the device against a bearing surface of the assembly and an opposite end of the device against a further bearing surface of the assembly whereby the first and the second objects are retained against withdrawal from one another by the device, the opposite ends of the device being slidable relative to each other against the biasing force.

25. The assembly of claim 24, wherein the bearing surfaces of the assembly comprise a bearing surface of one of the first and second objects and a bearing surface of the other one of the first and second objects and opposite ends of the device are opposite longitudinal ends and the device blocks withdrawal of the first and the second objects from one another in the lengthwise direction of the device.

26. The assembly of claims 24 or 25, wherein one of the first and the second objects has an opening and the other of the objects has a through passageway, and the objects are slidably received one within the other whereby the through passageway overlies the opening to form the cavity in which the securing device is located, the securing device lying in both the opening and the through passageway blocking sliding withdrawal of the first and second objects from one another.

27. The assembly of claim 26, wherein the casing of the securing device lies on a support surface of the one of the first and second objects below the opening of that object.

28. The assembly of claim 27, wherein the support surface mates with a correspondingly profiled outer surface of the casing of the securing device.

29. The assembly of claim 24 or 25, wherein one of the first and the second objects has a rearwardly extending section with an upstanding rear end portion, the upstanding rear end portion defining the cavity in which the securing device is positioned in combination with a rearwardly facing portion of the other of the objects, the opposite ends of the securing device being pressed against the upstanding end portion and the rearwardly facing portion of the first and the second objects by the biasing force whereby the objects are drawn together and retained in abutment with one another by the securing device.

30. The assembly of claims 29, wherein the one of the first and the second objects has a rearwardly projecting wall and the other of the objects has a rearwardly directed channel extending from the front of that object to the cavity, the rearwardly projecting wall being fitted in the channel.

31. The assembly of claim 30, wherein a slot formation is defined by a lower portion of the channel and the rearwardly extending section of the one of the first and the second objects is slidably received in the slot formation whereby the slot formation blocks the rearwardly extending section from being lifted in an upward direction.

32. The assembly of any one of claims 24 to 31, wherein the rearwardly extended section has a raised support on which the securing device is rests.

33. The assembly of claim 24, wherein the bearing surfaces are bearing surfaces of one of the first and second objects and the opposite ends of the device are opposite longitudinal ends, and the securing device blocks withdrawal of the first and second objects from one another in a cross-wise direction of the device.

34. The assembly of claim 33, wherein one of the objects has a channel in which a retainer of the other objects is slidably received and the cavity receiving the securing -36- device is formed in said one of the objects, wherein the bearing surfaces of the assembly are surfaces of opposite side walls defining the cavity, and the device is located in the cavity adjacent the retainer whereby the device lies across the channel to block sliding withdrawal of the one said object from the retainer, and wherein the reception of the retainer in the channel blocks lifting of the one said object from the other of the objects.

35. The assembly of claim 34, wherein the channel is a closed-ended channel and the retainer is located in the channel between the closed end of the channel and the securing device.

36. The assembly of claim 34, wherein retainer is located in abutment with the closed end of the channel.

37. The assembly of any one of claims 24 to 36, wherein the biasing system comprises a pair of spaced apart magnets, wherein the magnets are arranged for being driven one toward the other when the opposite ends of the securing device are pressed against the bearing surfaces of the assembly, and wherein the biasing force is a magnetic force of repulsion generated between the magnets.

38. The assembly of claim 37, wherein the magnets are spaced apart from each other along the casing in a magnetically repelling relationship to one another.

39. The assembly of claim 37 or 38, wherein each of the magnets is retained in a respective portion of the casing wherein the portions of the casing are slidable relative to one another against the biasing force.

40. The assembly of any one of claims 37 to 39, wherein each of the magnets is disposed in a respective holder, the holders being of an essentially non-magnetically attracted material and spacing each said magnets from a respective surrounding side wall of the casing, and wherein the casing is fabricated from magnetically attracted material.

41. The assembly of claim 40, wherein each of the magnets is magnetically coupled to a corresponding end of the casing.

42. The assembly of claim 40, wherein each said holder is cup-shaped and encases the respective said magnet.

43. The assembly of claim 42, wherein each said cup-shaped holder has an open end and is seated on a respective spacer located between the holder and the -37- corresponding internal end of the casing, the spacer covering the open end of the holder and being formed from an essentially non-magnetically attracted material.

44. The assembly of any one of claims 24 to 43, wherein the first and the second objects are machinery components.

45. The assembly of any one of claims 24 to 44, wherein the first and second objects are ground engaging tools (G.E.T).

46. The assembly of any one of claims 24 to 45, wherein the first and second objects are a ground engagement tool (G.E.T) and an adaptor for theG.E.T.

47. The assembly of claim 46, wherein the adaptor is an adaptor of an excavation bucket or cutter head for coupling of the ground engagement tool to the excavation bucket or cutter head.

48. A method for securing an assembly of a first object and a second object together with a securing device, the method comprising: providing the securing device, the securing device having a casing and a biasing system housed in the casing, the biasing system providing biasing force for pressing one end of the device against a bearing surface the assembly and an opposite end of the device against a further bearing surface of the assembly, the opposite ends of the device being slidable relative to each other against the biasing force; forming the assembly of the first and the second objects wherein one of the objects is slidably received by the other of the objects, the assembly having an outwardly facing cavity opening to the exterior of the assembly; and inserting the securing device into position in the cavity with each said end of the device pressing against the corresponding said bearing surface of the assembly whereby the device blocks sliding withdrawal of the objects from one another.

49. The method of claim 48, wherein the bearing surfaces of the assembly comprise a bearing surface of one of the first and second objects and a bearing surface of the other one of the first and second objects and the opposite ends of the device are opposite longitudinal ends and the device blocks withdrawal of the first and the second objects from one another in the lengthwise direction of the device.

50. The method of claim 48 or 49, wherein the cavity on which the securing device is inserted is formed by the assembly of the first and second objects. -38-

51. The method of claim 48, wherein the bearing surfaces are bearing surfaces of one of the first and second objects and the opposite ends of the device are opposite longitudinal ends, and the device is for blocking withdrawal of the first and second objects from one another in a cross-wise direction of the device.

52. The method of claim 51, wherein the bearing surfaces are surfaces of opposite side walls defining the cavity.

53. The method of any one of claims 48 to 52, wherein the first and the second objects are machinery components.

54. The method of any one of claims 48 to 52, wherein the first and second objects are ground engaging tools (G.E.T).

55. The method of any one of claims 48 to 52, wherein the first and second objects are a ground engagement tool (G.E.T) and an adaptor for the G.E.T.

56. The method of claim 55, wherein the adaptor is an adaptor of an excavation bucket or cutter head for coupling the ground engagement tool (G.E.T) to the excavation bucket or cutter head.

57. A ground engagement tool for being secured to an adaptor for the ground engagement tool by a securing device, wherein the ground engagement tool has a bearing surface for engagement with the securing device and at least one abutment surface for abutment with a corresponding surface of the adaptor, and is configured for sliding engagement with the adaptor to form an assembly of the ground engagement tool and the adaptor whereby an outwardly facing cavity opening to the exterior of the assembly is formed by the ground engagement tool and the adaptor for insertion of the securing device into position in the cavity to block sliding withdrawal of the ground engagement tool and adaptor from one another, the bearing surface of the ground engagement tool being located to face in an opposite direction to a bearing surface of the adaptor for forcing the abutment surface of the ground engagement tool against the corresponding surface of the adaptor when the securing device is inserted in position in the cavity with one end of the securing device pressing against the bearing surface of the ground engagement tool and an opposite end of the securing device pressing against the bearing surface of the adaptor.

58. An adaptor for a ground engagement tool, wherein the adaptor has a bearing surface for engagement with a securing device for securing the adaptor and the ground -39- engagement tool together, and at least one abutment surface for abutment with a corresponding surface of the tooth, the adaptor being configured for sliding engagement with the ground engagement tool to form an assembly of the adaptor and the ground engagement tool whereby an outwardly facing cavity opening to the exterior of the assembly is formed by the adaptor and the ground engagement tool for insertion of the securing device into position in the cavity to block sliding withdrawal of the adaptor and the ground engagement tool from one another, the bearing surface of the adaptor being located to face in an opposite direction to a bearing surface of the ground engagement tool for forcing the abutment surface of the adaptor against the corresponding surface of the ground engagement tool when the securing device is inserted in position in the cavity with one end of the securing device pressing against the bearing surface of the adaptor and an opposite end of the securing device pressing against the bearing surface of the ground engagement tool.