WO2000020696A1

WO2000020696A1 - A wedge and spool assembly

Info

Publication number: WO2000020696A1
Application number: PCT/AU1999/000863
Authority: WO
Inventors: Robert Kent Emrich; Donald Maurice Conklin; Leslie Herbert Fryer; Fraser Jonathon Batts; Darren Craig Muir
Original assignee: The Ani Corporation Limited; Esco Corporation
Priority date: 1998-10-02
Filing date: 1999-10-05
Publication date: 2000-04-13

Abstract

A wedging device is suitable for insertion in aligned apertures between components such as an adaptor and a dragline bucket. The wedging device is expandable to wedge together the adaptor and the dragline bucket. The wedging device has a typically C-shaped insert or spool cooperating with a wedge element, the spool and wedge element being interconnected by a tensioning screw which in some embodiments upon rotation in either direction respectively forces the wedge downwardly so that the wedging device achieves its wedging function, and in the reverse direction the wedge is pulled up to release the engagement so that the parts can be disconnected. In another embodiment the tensioning screw is used for achieving the wedging engagement but is simply removed by unscrewing and an auxillary screw device is inserted to achieve extraction of the wedge and disconnection.

Description

A WEDGE AND SPOOL ASSEMBLY

FIELD OF THE INVENTION

The present invention relates to a wedging device for fixing an attachment to a support means. The wedging device may be used to connect an attachment to excavating equipment such as a dragline bucket, rope/hydraulic shovel or other excavating device. Accordingly, embodiments of the invention find application in the landscaping and mining fields . BACKGROUND OF THE INVENTION

Devices for fixing attachments such as teeth or adaptors carrying sacrificial wear parts to dragline buckets are known in the prior art.

Generally, the adaptor is fitted onto a corresponding position of an excavation device lip and a spool inserted into a passageway formed through the adaptor and the lip portion. Conventional practice has been for a wedge to be inserted into the passageway between the spool and a tip region of the nose portion and was then hammered into the passageway with a sledge hammer causing the spool to move rearwardly from the tip of the nose portion and press against the adaptor to thereby force the adaptor tightly onto the nose portion.

However, any misalignment in the openings through the adaptor and nose portion forming the passageway, due to wear or improper fitting of the adaptor, caused difficulty when inserting the wedge. Moreover, chips of metal could fly off the wedge or hammer as the wedge was being forced into the passageway posing a safety problem for persons in the immediate area. In addition, a sledge hammer needed to be available in order to insert the wedge, the use of which also posed a safety problem.

A wedging device comprising a wedge connected to a spool by means of a bolt is disclosed in US patent 4433496. The wedge has an arcuate surface which bears against a

SubstituteSheet correspondingly contoured arcuate surface on the spool . When the bolt is rotated the wedge is drawn up the arcuate surface of the spool so that a curved contact surface of the wedge is placed into abutment with the nose portion of the dragline bucket. However, the wedge exerts an offset force against the nose portion causing the adaptor to skew as it is drawn onto the nose portion when the bolt is rotated which presents difficulty to the workperson fixing the adaptor in position. A wedging device consisting of two spools and a separate wedge assembly is disclosed in patent application WO 95/01481. The wedge assembly is comprised of two wedges and a bolt which extends through a passageway formed in one of the wedges and is threadably received in the other wedge. In use, the wedge assembly is positioned between the spools in the passageway formed through the adaptor and the nose portion of the dragline bucket, and the bolt rotated so that the spools are forced apart as the wedges are drawn toward each other causing one of the spools to be pressed against the nose portion and the other spool to be pressed against the adaptor. Accordingly, the movement of the wedges results in the adaptor being drawn onto, and fixed to, the nose portion.

However, the substantial forces which are exerted on the device during an excavating operation can cause a wedge to tilt and so bend the bolt in a region adjacent to the wedge. This may result in difficulty when loosening the bolt to remove the wedging device, and possibly seizure of the device in the dragline bucket. It may also lead to increased downtime of the dragline bucket while the wedging device is removed or at the least, the need for maintenance to the wedging device .

A further wedging device is disclosed in Australian Patent 676060 based on Application No 68677/94. This device consists of a single spool and a separate wedge assembly comprising two wedges receiving a bolt. As with the device disclosed in WO 95/01481 the bolt extends through a passageway formed in one of the wedges and is threadably received in the other wedge. Accordingly, the arrangement suffers from the same drawback as the device disclosed in WO 95/01481 in that the bolt is prone to bending forces which may result in damage to the wedging device.

Due to the size of dragline buckets as well as the nature of the forces exerted on the buckets during use, the wedging devices are correspondingly large and typically weigh about 6 kg or more.

As the wedging devices disclosed in WO 95/01481 and AU 68677/94 are comprised of a number of separate unconnected parts, difficulties can arise when fixing the devices in position on a dragline bucket due to the need to align the separate parts with each other. The insertion of the wedging devices may also be hampered if there is misalignment of the adaptor and nose portion of the dragline bucket . The weight of a wedging device of the type disclosed in WO 95/01481 and AU 68677/94 further compounds the difficulty in holding the separate parts of the wedging device together while being lowered into the passageway defined in the nose portion and adaptor. Furthermore, it is common for a workperson to be positioned so as to receive the wedging device from below the passageway as it is lowered into the adaptor and nose portion, and hold the device in position while another workperson tightens the bolt of the wedging device from above the passageway to thereby wedge the separate parts of the device together. The fact that the wedging device exists as separate parts poses safety risks not only to the workperson receiving the device as it is lowered into the passageway but also to the workperson holding the parts together while lowering the device. A further development in the art is disclosed in Australian Patent Application No. 48109/96 which discloses a wedging device locatable between two components and consisting of a plurality of parts connected together such that the device remains as a single cohesive assembly during all phases of operation, wherein the parts comprise: a spool having two inclined surfaces; a pair of wedges arranged such that the wedges are able to be moved up the inclined surfaces, one to each; and a rotatable threaded member extending through an aperture formed in the spool and being received by the wedges ; wherein rotation of the threaded member when the device is located between the two components causes the wedges to move toward each other up the respective said inclined surfaces of the spool and be pressed against one of the components to thereby force the spool against the other said component .

In order to cause the wedges to move up the inclined surfaces, the wedging device may be provided with a nut having a female thread engaged with a male thread formed on a shaft of the threaded member, wherein the nut is arranged to be able to exert a pressure on one of the wedges so that the nut and threaded member together force the wedges toward each other when the threaded member is rotated.

Alternatively, the male thread of the threaded member may be engaged with a female thread provided on the one wedge itself.

So that the wedges may move up the inclined surfaces the aperture formed in the spool and/or apertures defined in the wedges which receive the threaded member can have a width which is substantially greater than that of the shaft of the threaded member.

The threaded member is formed such that the engagement of the threaded member with the nut or a female thread formed in one of the wedges holds the wedges on the threaded member. This, together with the reception of the threaded member in the aperture formed in the spool, maintains the wedging device in the form of a single cohesive assembly. The present invention is directed to embodiments which can provide numerous advantages over previous proposals and in particular aimed to provide safe and convenient fitting and removal in a rugged working environment with a high degree of safety and speed. Downtime of very expensive mining equipment must be minimised and with this requirement in mind embodiments of the present invention facilitates such fitting with just one person.

Broadly, the present invention is found in a wedging device for securing together first and second components having respective apertures which align such that the wedging device can be inserted through the apertures and expanded in a wedging action to secure the components together, the wedging device having a) an insert member, b) a wedging member, c) a tensioning screw for interconnecting the insert member and the wedging member, d) the insert member and the wedging member having respective abutment surfaces shaped such that relative movement in a first direction between the insert member and the wedging member causes the overall width of the members to expand for wedging engagement in the aligned apertures in the first and second components, e) the tensioning screw having (i) a screw-threaded shank portion and

(ii) an end portion, f) a body portion associated with one of the insert member and the wedge member and defining a screw-threaded bore for engagement with the shank of the tensioning screw, g) an abutment portion associated with the other of the insert member and the wedge member for abutment with the tensioning screw to receive axially directed force when the tensioning screw is rotated to cause the relative motion of the insert member and the wedging member in the first direction, and h) access means providing access to an end portion of the tensioning screw when the device is assembled and in use the access means permitting the tensioning screw to receive applied torque from a tool to rotate the tensioning screw.

The temporary screw, for example, could be a separately supplied component and thus the invention subsists also in the component parts (or some of them) adapted to be interconnected to achieve in use the inventive concept .

The present invention in one important embodiment provides a wedging device for securing together first and second components having respective apertures which align such that the wedging device can be inserted through the apertures and expanded in a wedging action to secure the components together, the wedging device having a) an insert member, b) a wedging member, c) a tensioning screw for interconnecting the insert member and the wedging member, d) the insert member and the wedging member having respective abutment surfaces shaped such that relative movement in a first direction between the insert member and the wedging member causes the overall width of the members to expand for wedging engagement in the aligned apertures in the first and second components, e) the tensioning screw having i) a head portion providing first and second spaced, confronting, laterally extending abutment surfaces with a neck portion extending between the first and second abutment surfaces , and ii) a screw threaded shank portion, f) the head portion of the tensioning screw being adapted to be rotatably mounted on one of the insert member and the wedging member, g) the screw threaded shank portion being adapted to engage with the other of the insert member and the wedging member which is threaded such that i) rotation of the head portion in a first rotary direction causes the first of the abutment surfaces to apply displacement force so that the wedge member and the insert member move relative to one another in the first direction to cause wedging engagement, and ii) rotation of the head portion in the opposite rotary direction causes the second of the abutment surfaces to apply force to move the wedge member and the insert member relative to one another in an opposite direction to release the wedging engagement . An alternative important embodiment is one in which the head portion is disposed in a cavity having end faces which confront an end face of the head and a second face extending at the junction of the head and shank portion, the head portion and the shank portion being rotatably mounted so that the screw can be rotated to tension and de-tension the wedging device.

Access is provided to an end of the tensioning screw for application of torque.

Preferably the head portion in use abuts with the wedging member and the threaded shank portion is adapted to engage in a correspondingly threaded cavity through a portion of the insert member.

An advantageous embodiment of the invention is one in which the insert member has an arm portion adapted to engage and support the wedging device upon presentation to the components thereby facilitating rotation of the tensioning screw to establish wedging interconnection.

Most preferably the form of the wedging device is such that the insert member is generally C shaped with a face inclined to the first direction to provide a ramp and the wedging member has a corresponding ramp surface for engaging the ramp and a remote surface adapted to engage the other component .

In a further embodiment, the present invention, there is provided a wedging device for securing together first and second components having respective apertures which align such that the wedging device can be inserted through the apertures and expanded in a wedging action to secure the components together, the wedging device having a) an insert member, b) and a wedging member, c) the insert member having a body portion which in use extends through the aligned apertures of the first and second components and has a laterally extending arm with means for engaging with a portion of one of the components whereby on initial assembly, with the apertures of the first and second components aligned vertically, the insert member remains in a supported position d) the wedging member includes first and second opposed abutment walls which taper towards one another to define a wedge structure and respectively for abutment on a wall of the aperture in the first component remote from the insert member and onto an opposed surface of the body portion of the insert member, e) the body portion of the insert member having a screw threaded cavity for receiving a tensioning screw, f) the wedge member having a cavity for accommodating the portion of the body member defining the screw threaded cavity of the insert member g) the wedge member having a transverse wall with access means to permit the tensioning screw to be inserted into the cavity and engaged in the screw threaded portion of the insert member and tightened with a head of the screw applying force to the transverse wall substantially along the axial direction of the aligned apertures in the first and second components, and h) the wedging device being such that tightening of the tensioning screw moves the wedge member along that axial direction and so that reaction forces expand the wedging device at right angles to that axis, whereby an abutment surface on the insert member on its opposite face from the wedge member is pushed into abutment with a confronting portion of the second component and the second component is urged substantially at right angles to said axis relative to the first component.

Embodiments of the invention can be arranged as elegant, simple and effective devices which use a wedge system with a single incline or tapered surface with a single wedge member to be moved. Since the insert member has means for cooperation preferably with the second component, an insert member can be simply placed in position and the operator then has both hands free to insert and then tighten the wedge member. A most important feature of preferred embodiments is one in which a screw system is provided for subsequent removal of the wedging device. This may be provided by the tensioning screw being operable in one direction to cause wedging and in the other direction to cause unwedging. An alternative is to provide a screw threaded aperture in a transverse wall of the wedging device and in which the normal tensioning screw is a clearance fit. For removal of the wedging device, the normal tightening screw is removed entirely using a wrench and then a larger diameter screw is inserted in screw threaded engagement in the aperture in the transverse wall and its tip engages on a portion of the insert member surrounding the aperture into which the tensioning screw originally fitted. Rotation of the screw extracts the wedging device until it is loose and the screw (which preferably projects well beyond the second component) can then be gripped to pull the wedging device out of the aligned apertures . The insert member can then be readily retrieved and thus the components are separated.

A preferred embodiment, however, is one in which the tensioning screw has a captive head portion freely rotatable in and retained in a portion associated with one of the insert member and the wedging member and the other has a screw threaded bore for receiving the threaded shank portion of the tensioning screw whereby rotation of the screw in a first direction causes the insert member and wedging member to be moved relative to one another in a wedging direction and rotation of the tensioning screw in the opposite direction causes displacement force to be provided to reverse the relative movement for unwedging the device. It may be preferred that the captive head portion of the tensioning screw is located in a portion associated with the wedging member e.g. by lateral insertion into a slotted arm of the wedging member and the screw threaded shank is engaged in a threaded bore associated with the insert member, for example, in a corresponding laterally extending arm of the insert member. Advantageously in this arrangement the head portion can be uppermost for receiving engagement with a spanner or wrench.

Thus , preferred embodiments can be advantageous in obviating any hammering to install or remove the wedging device. The device is removable readily in a field situation where the application of mechanical advantage through a large wrench can be used.

In another aspect, the invention extends to an adaptor for mounting a working tool on an implement and arranged to be secured in position by a wedging device in any one of the forms described herein. Preferably, the adaptor has at its rearward end portion transverse walls for inter-engaging with the insert member and preferably there is included a recess for co-operating with a projecting lug from the laterally extending arm of the insert member.

In yet a further aspect, the invention extends to a method of mounting one component on another wherein a wedging device in any one of the forms described herein is utilised.

By way of example only, embodiments of the invention will now be described with a reference to the accompanying drawings, of which:

Fig. 1 is a perspective view of an embodiment applied to securing a replaceable digging tool to the front lip of an excavator bucket;

Fig. 2 is a schematic cross-sectional view taken along the line II - II but prior to the wedging device being inserted; Fig. 3 is an enlarged side elevation of the wedging device showing just the wedging member in cross-sectional view;

Fig. 4 schematically illustrates assembly with the spool member of the wedging device of Fig. 3 initially positioned;

Fig. 5 illustrates the wedging member inserted and engaged with a spool device at the commencement of tightening of the wedging member;

Fig. 6 illustrates the use of an extraction screw about to be rotated to extract the wedging device from its wedging position;

Fig. 7 is a part cross-sectional side elevation through a second embodiment of the wedging device embodying the invention; Fig. 8 is a cross sectional view of the second embodiment and corresponding to Fig. 7 but showing just the insert member installed and supported on a second component of two inter-engaged components which are to be wedged together;

Fig. 9 is a view corresponding to Fig. 8 showing the assembled wedging device and disposed for rotation to be applied to cause wedging engagement;

Fig. 10 is a view corresponding to Fig. 9 but showing the wedging device when installed in wedging engagement and adapted to be unwedged by counter rotation of the tensioning screw;

Fig. 11 is a part cross-sectional side elevation of a third embodiment with the wedging member in cross-section;

Fig. 12 is an end view of Fig. 11;

Fig. 13 is a plan view of Fig. 11; Fig. 14 is a part cross-sectional front elevation of a fourth embodiment with the wedging member in cross-section;

Fig. 15 is an end elevation of Fig. 14;

Fig. 16 is a plan view of Fig. 14;

Fig. 17 is a front elevation of Fig. 14; Fig. 18 is an inverted plan cross-sectional view taken along the line AB-AB of Fig. 17;

Fig. 19 is an inverted plan view in cross-section taken along the line AW-AW of Fig. 17;

Fig. 20 is an inverted plan cross-sectional view taken along the line AX-AX of Fig. 17; and

Fig. 21 is an inverted plan cross-sectional view taken along the line AY-AY of Fig. 17.

In various embodiments like numerals have been used for corresponding parts . Referring first to Figs 1 and 2, an excavator bucket has a leading lip 10 which extends generally horizontally in normal use, the lip terminating in a rounded nose 11 and having a rectangular or rounded aperture 12 at each location where a replaceable digging tooth 13 is to be mounted. Each tooth 13 is mounted on a shoe-like adaptor 14 by means of a conventional wedging pin (not shown) . At regular intervals, just the tooth is removed in the field and replaced. The adaptor 14 also requires replacing at intervals and this embodiment of the invention uses a wedging device shown in overall view prior to tightening in Fig. 1 and in more detailed side elevation in Fig. 3. The wedging device comprises a generally C-shaped spool 15 and a wedge unit 16, the wedging device being adapted to fit into the aperture 12 in the lip and to urge the adaptor 14 rearwardly relative to the lip 10, i.e. in the direction of arrow A shown in Fig. 2. As most clearly seen in Fig. 2, the adaptor is forked and comprises upper and lower arms 17 and 18 with rearwardly extending cavities 19 and 20 and transverse walls 21 and 22 in the central region and over which arms 23 and 24 of the C-shaped spool extend. The upper transverse wall 21 has a recess 25 into which a lug 26 of the upper arm of the spool extends in hooking engagement, whereby the spool is retained in position. This is most clearly shown in Fig. 4 during initial assembly. A single operator can readily achieve this assembly and then proceed to insert the wedge unit 16.

Fig. 5 shows the wedging unit 16 positioned into its initial position and a tensioning screw inserted and ready for tightening. As shown in Fig. 1, the wedging unit in plan view is generally U-shaped and is downwardly tapered with a front wedging wall 28 and a pair of spaced rear walls 29 between which a cavity 30 is defined, the walls 29 being adapted to engage in abutment with an inclined front face 31 of the spool 15. Near its upper end, the wedging unit has an interior transverse wall 32 having an enlarged screw threaded bore 33 through which the tightening screw 27 is a clearance fit. A stack of belleville washers 34 support the head 35 of the screw 27 on the transverse wall 32. The operator simply positions the threaded leading end of the screw 27 through the bore 33 and rotates it to screw threadably engage in a threaded bore 36 which extends downwardly through an integral projection 37 of the spool 15, the tensioning screw thereby extending parallel to the inclined leading face 31 of the spool. The screw 37 is tightened in a clockwise direction as indicated in Fig. 5 thereby drawing down the wedging unit 16 and consequentially causing the wedging device to expand in the horizontal direction with a reaction force applied between surfaces 28 of the wedging unit and 12 of the aperture in the lip. This forces a rearwardly directed interior surface 39 of the spool onto confronting respective surfaces of the transverse walls 21 and 22 so that the adaptor moves rearwardly relative to the lip 10 whereby the small clearance shown in Fig. 2 between the nose and the interior of the adaptor is taken up. Further tightening of the screw 27 causes tensioning of the adaptor whereby its forked arms 17 and 18 are drawn down onto the substantially parallel top and bottom surfaces of the lip. Although not shown in Fig. 2, relative to the lip 10 the forked arms 17 and 18 are slightly divergent to facilitate fitting and to ensure a good clamping effect whereby despite high level of abrasion and shock loads over an extended period of time the adaptor remains firmly fixed to the lip 10 of the bucket .

When the adaptor needs to be removed, a large wrench is simply used to unscrew the tensioning screw 27 and in its place to insert a larger diameter extraction screw 40 shown in Fig. 6. The extraction screw 40 is rotated clockwise and engages in the screw threaded bore 33 and the tip of the extraction screw abuts on the projection 37 around its screw threaded opening but does not engage therein by virtue of its larger diameter. Clockwise rotation of the screw 40 thereby draws the wedging unit 16 upwardly until all tension is removed and then the operator can simply grasp the head of the extraction screw 40 and lift out the wedging device. The spool 15 is then extracted and it is a simple task then to remove the adaptor .

Thus, particularly this preferred embodiment of the invention can provide for a high degree of safety, single operator performance and minimal field down time in order to replace adaptors when worn. Furthermore, a reliable and secure gripping action can be achieved and simple and speedy periodic checking of the tension applied to the tensioning screw 27 is all that is required.

Referring now to Figures 7 to 10, in the second embodiment the form of the tensioning screw 27 and its accommodation on transverse wall 32 is altered. The tensioning screw 27 has a head portion comprising the usual hexagonal head 35 and a spaced collar 35A between which a plain shank portion or neck 35B is provided, the portion 35B having a greater axial length than the thickness of the transverse wall 32. In this embodiment the transverse wall has a slot extending into the wall from the left edge as shown in Figure 7 so that the neck can simply be slipped laterally into the slot prior to assembly.

As shown in Figure 8, the insert member 15 is supported on the second component in the same manner as the first embodiment. Clockwise rotation, as shown in Figure 9, causes the screw threaded shank of the tensioning screw to threadably engage in the lateral arm 37 for the insert member and thereby the wedging member 16 is drawn downwardly and urged into wedging engagement . In order to disassemble the parts, an operator simply applies a spanner to the top of the tensioning screw and rotates it in an anti-clockwise direction as shown in Figure 10 thereby causing the collar 35A to abut against the lower surface of the transverse wall 32 thereby forcing the wedging member upwardly and out of wedging engagement. Referring now to the embodiment of Figures 11 to 13 , the C-shaped spool 15 has the extra feature of a handle 47 to facilitate manipulating the wedging device and its initial installation. Otherwise like parts have been given like reference numerals .

This embodiment is characterised by the tensioning screw 27, when rotated, applying force downwardly to drive the wedge unit 16 down for wedging engagement or upon reverse rotation to drive the wedge unit upwardly for disassembly.

This function is achieved by the provision of a cavity 40 for accommodating the head 35 of the tensioning screw 27 along with a series of washers 44 located on an upper shank portion 43. The washers are supported on a pair of ribs 42 one of which extends behind the tensioning screw (as seen in Figure 11) and the other wedge will be located in front of the screw. The ribs 42 are integral with the wedge unit 16, as is a tranverse wall 41 having a lower surface confronting the free end of the head of the tensioning screw.

The transverse wall 41 also has an access bore 46 for receiving an alien key which engages in a hexagonal aperture 45 in the end of the head 35 of the tensioning screw 27 for rotating the screw in either direction.

The projection 37 from the spool has a screw threaded bore in which the screw-threaded portion of the shank 43 is engaged.

Thus, the entire unit can be assembled, dropped into position with the lug 26 engaging in a corresponding recess in the adaptor and from above an alien key is inserted and driven to tighten the wedging unit. To remove the wedging unit, reverse rotation is applied to loosen the wedge so that the whole unit can be removed.

Referring now to Figures 14 to 21 which shows a fourth embodiment, similar mechanical principles are used but in this version the upper end of the screw 51 is a reduced diameter free end portion 50 having a hexagonal outer profile and accommodated in an access recess 53 in the upper portion of the wedge unit 16 and above the transverse wall 57 of the wedge. In this case the transverse wall 57 of the wedge has a screw threaded bore for threaded engagement with the threaded portion of the shank 52 of the tensioning screw and the lower end of the tensioning screw is retained but freely rotatable within the projection 37A from the spool 15.

At the lower end, the tensioning screw has a plain head 54 on which is supported a group of washers 44 and immediately above the projection 37A a retaining collar 55 is provided on the tensioning screw.

Assembly comprises the steps of locating the washers 44 on the shank of the tensioning screw; the shank is then upwardly inserted through the bore in the projection 37A so that the washers abut the lower surface of the projection. The collar 55 is screw threadably engaged on the shank and rotated to move down to be adjacent the top of the projection 37A and to align a cross bore in the shank with a cross bore in the collar so that a pin 56 can be inserted to lock together the two components . The wedge unit is then lowered into position with the screw threaded bore in the transverse wall 57 placed over the end portion 50 of the tensioning screw which is accommodated in a U-shaped cross-sectional cavity 58 in the wedge. A socket tool is applied to rotate the tensioning screw by engagement with the free end 50, thereby causing the wedge unit to be screwed threadably engaged and pulled downwardly to expand the wedge unit. Reverse motion removes the wedge unit upwardly.

Claims

1. A wedging device for securing together first and second components having respective apertures which align such that the wedging device can be inserted through the apertures and expanded in a wedging action to secure the components together, the wedging device having a) an insert member, b) a wedging member, c) a tensioning screw for interconnecting the insert member and the wedging member, d) the insert member and the wedging member having respective abutment surfaces shaped such that relative movement in a first direction between the insert member and the wedging member causes the overall width of the members to expand for wedging engagement in the aligned apertures in the first and second components, e) the tensioning screw having

(i) a screw-threaded shank portion and (ii) an end portion, f) a body portion associated with one of the insert member and the wedge member and defining a screw-threaded bore for engagement with the shank of the tensioning screw, g) an abutment portion associated with the other of the insert member and the wedge member for abutment with the tensioning screw to receive axially directed force when the tensioning screw is rotated to cause the relative motion of the insert member and the wedging member in the first direction, and h) access means providing access to an end portion of the tensioning screw when the device is assembled and in use, the access means permitting the tensioning screw to receive applied torque from a tool to rotate the tensioning screw.

2. A wedging device as claimed in claim 1, wherein the end portion of the tensioning screw includes a head portion providing first and second spaced, laterally extending abutment surfaces adapted to engage with respective abutment portions of the engagement portion, the first and second abutment portions confronting the first and second abutment surfaces of the tensioning screw, whereby rotation of the head portion in a first rotary direction causes the first of the abutment surfaces of the head portion to apply displacement force through its confronting abutment portion so that the wedge member and the insert member move relative to one another in the first direction to cause wedging engagement, and rotation of the head portion in the opposite rotary direction causes the second of the abutment surfaces of the head portion to apply force through its confronting abutment portion to move the wedge member and the insert member relative to one another in an opposite direction to release the wedging engagement .

3. A wedging device as claimed in claim 2 wherein the first and second abutment surfaces confront one another and define shoulders at opposite ends of an intermediate portion of the tensioning screw.

4. A wedging device as claimed in any one of the preceding claims, wherein the tensioning screw has an enlarged head portion at one end adapted to be engageable with the tool to apply torque in either direction to the tensioning screw to tension and de-tension the screw.

5. A wedging device as claimed in claim 1, wherein the tensioning screw has a head portion at the same end of the shank to the end portion and the head portion is rotatably mounted in a cavity in the abutment portion with end faces of the head portion confronting walls of the cavity for abutment respectively during tensioning and de-tensioning of the wedging device .

6. A wedging device as claimed in any one of the preceding claims, wherein the body portion is provided on the insert member and the abutment portion is provided on the wedging member.

7. A wedging device as claimed in claim 1, wherein the tensioning screw has a head portion at an opposite end of the shank to the end portion and a portion of the shank adjacent the head portion is rotatably mounted on the abutment portion, the end portion projecting through the screw-threaded bore of the body portion.

8. A wedging device as claimed in claim 7, wherein the abutment portion is part of the insert member and the body portion is part of the wedge member and located above the abutment member, the access means being an aperture through an upper portion of the wedge member.

9. A wedging device as claimed in claim 8, wherein the tensioning screw has a threaded collar adapted to be engaged on the shank and fixed in a selected position spaced from the head portion with the head portion and collar on opposite sides of the abutment portion.

10. A wedging device as claimed in any one of the preceding claims, wherein the insert member has (i) a main portion which in use extends through the aligned apertures of the first and second components and (ii) a laterally extending arm with means for engaging with a portion of one of the components whereby on initial assembly, with the apertures of the first and second components aligned vertically, the insert member is supported by the arm.

11. A wedging device as claimed in claim 10, wherein the means for engaging includes a downwardly extending projection for engaging in a corresponding recess in the second component whereby the insert member is retained in a cantilever manner.

12. A wedging device as claimed in claim 10 or claim 11 wherein the insert member is generally C-shaped with upper and lower arms extending from the main portion to provide the C-shaped structure, the upper arm of the C-shaped structure providing the laterally extending arm, the main portion providing a wall portion adapted to be substantially vertical in normal installation and having a first side for abutment against respective portions of the second component and an opposite side for sliding engagement with a corresponding inclined wall of the wedging member.

13. A wedging device as claimed in any one of the preceding claims, wherein the wedging member in plan view is generally U-shaped with the arms of the U-shaped terminating in an inclined face adapted for wedging engagement with a confronting surface of the insert member.

14. A wedging device as claimed in claim 1 wherein a transverse wall on the wedge member provides the abutment portion and provides a screw threaded bore through which the tensioning screw is a clearance fit and which is adapted to be screw threadably engaged, after removal of the tensioning screw, by a larger diameter extraction screw, rotation of which causes relative movement of the insert member and the wedging member in a direction opposite to the first direction to permit removal of the wedging device.

15. A wedging device for securing together first and second components having respective apertures which align such that the wedging device can be inserted through the apertures and expanded in a wedging action to secure the components together, the wedging device having a) an insert member, b) a wedging member, c) a tensioning screw for interconnecting the insert member and the wedging member, d) the insert member and the wedging member having respective abutment surfaces shaped such that relative movement in a first direction between the insert member and the wedging member causes the overall width of the members to expand for wedging engagement in the aligned apertures in the first and second components, e) the tensioning screw having i) a head portion providing first and second spaced, confronting, laterally extending abutment surfaces with a neck portion extending between the first and second abutment surfaces, and ii) a screw threaded shank portion, f) the head portion of the tensioning screw being adapted to be rotatably mounted on one of the insert member and the wedging member, g) the screw threaded shank portion being adapted to engage with the other of the insert member and the wedging member which is threaded such that i) rotation of the head portion in a first rotary direction causes the first of the abutment surfaces to apply displacement force so that the wedge member and the insert member move relative to one another in the first direction to cause wedging engagement, and ii) rotation of the head portion in the opposite rotary direction causes the second of the abutment surfaces to apply force to move the wedge member and the insert member relative to one another in an opposite direction to release the wedging engagement .

16. A wedging device for securing together first and second components having respective apertures which align such that the wedging device can be inserted through the apertures and expanded in a wedging action to secure the components together, the wedging device having a) an insert member, b) and a wedging member, c) the insert member having (i) a body portion which in use extends through the aligned apertures of the first and second components and (ii) a laterally extending arm with means for engaging with a portion of one of the components whereby on initial assembly, with the apertures of the first and second components aligned vertically, the insert member remains in a supported position d) the wedging member includes first and second opposed abutment walls which taper towards one another to define a wedge structure and respectively for abutment on a wall of the aperture in the first component remote from the insert member and onto an opposed surface of the body portion of the insert member, e) the insert member having a body portion defining a screw threaded cavity for engagement by a screw threaded shank of a tensioning screw, f) the wedge member having a cavity for accommodating the body portion g) the wedge member having a transverse wall with access means to permit the tensioning screw to be inserted into and engaged in the cavity of the body portion and tightened with a head of the screw applying force to the transverse wall substantially along the axial direction of the aligned apertures in the first and second components, and h) the wedging device being such that tightening of the tensioning screw moves the wedge member along that axial direction and so that reaction forces expand the wedging device at right angles to that axis, whereby an abutment surface on the insert member on its opposite face from the wedge member is pushed into abutment with a confronting portion of the second component and the second component is urged substantially at right angles to said axis relative to the first component.

17. A wedging device as claimed in claim 15 or claim 16 wherein the end portion of the tensioning screw includes a head portion providing first and second spaced, laterally extending abutment surfaces adapted to engage with respective abutment portions of the engagement portion, the first and second abutment portions confronting the first and second abutment surfaces of the tensioning screw, whereby rotation of the head portion in a first rotary direction causes the first of the abutment surfaces of the head portion to apply displacement force through its confronting abutment portion so that the wedge member and the insert member move relative to one another in the first direction to cause wedging engagement, and rotation of the head portion in the opposite rotary direction causes the second of the abutment surfaces of the head portion to apply force through its confronting abutment portion to move the wedge member and the insert member relative to one another in an opposite direction to release the wedging engagement.

18. A wedging device as claimed in claim 17 wherein the first and second abutment surfaces confront one another and define shoulders at opposite ends of a neck portion of the tensioning screw.

19. A wedging device as claimed in any one of claims 15 to 18 wherein the tensioning screw has an enlarged head portion at one end adapted to be engageable with the tool to apply torque in either direction to the tensioning screw to tension and de-tension the screw.

20. A wedging device for securing together first and second components having respective apertures which align such that the wedging device can be inserted through the apertures and expanded in a wedging action to secure the components together, the wedging device having a) an insert member, b) a wedging member, c) the insert member and the wedging member having respective abutment surfaces shaped such that relative movement in a first direction between the insert member and the wedging member causes the overall width of the members to expand for wedging engagement in the aligned apertures in the first and second components, d) the insert member and the wedging member being adapted to be interconnected by and driven into wedging engagement by a tensioning screw having

(i) a screw-threaded shank portion, and (ii) an end portion, e) a body portion associated with one of the insert member and the wedge member and defining a screw-threaded bore for engagement with the shank of the tensioning screw, f) an abutment portion associated with the other of the insert member and the wedge member for abutment with the tensioning screw to receive axially directed force when the tensioning screw is rotated to cause the relative motion of the insert member and the wedging member in the first direction, and g) access means providing access to an end portion of the tensioning screw when the device is assembled and in use the access means permitting the tensioning screw to permit the tensioning screw to receive applied torque from a tool to rotate the tensioning screw.