TECHNICAL FIELD The invention relates to a device for inserting and removing pivot pins to facilitate coupling together and uncoupling a tray and a rear-tipping mining and earth moving truck .

The word "tray" is understood herein to be a synonym of "bucket", "body" and "tub".

BACKGROUND ART

Rear-tipping haul trucks used in the mining industry are a focus of the applicant and the invention is

described particularly in the context of these trucks .

However, it is noted that the invention is not limited to this type of truck and extends generally to rear-tipping mining and earth moving trucks.

Typically, a tray of a rear-tipping haul truck is mounted for pivoting movement to the haul truck via a pair of pivot pins that are received in aligned openings in (a) a pair of male clevises (or other suitable pivot pin support members) that are mounted to the haul truck on opposite sides of the truck and (b) a pair of commentary pivot ears (or other suitable pivot pin support members) that are mounted to the tray on opposite sides of the tray.

The currently-accepted standard industry method for inserting pivot pins into pivot pin support members of a tray and a rear-tipping haul truck in order to couple together the tray and the haul truck involves (a) lifting and moving a tray via one or more cranes so that openings in the pivot pin support members of the tray and the haul truck are aligned and in a required position with respect to each other to receive pivot pins and (b) supporting the tray in this position via the cranes while pivot pins are manually inserted into the aligned openings in the pivot pin support members to thereby couple together the tray and the haul truck. The persons involved in the standard industry method have to be within the footprint of the tray in order to do the work.

The currently-accepted standard industry method for removing pivot pins to uncouple a tray and a rear-tipping haul truck, for example as is required from time to time to carry out maintenance work, is to use the reverse procedure to that described in the preceding paragraph.

Significantly, in many cases the existing pivot pins that couple together a tray and a haul truck, and which have to be removed as part of the removal method, are completely seized and large forces and/or lancing operations are required to remove the pins.

It is evident from the above that there are

significant efficiency and health and safety and

performance issues associated with the currently-accepted standard industry method for inserting and removing pivot pins to couple together and uncouple trays and rear- tipping haul trucks , respectively .

The currently-accepted standard industry method requires personnel to work under a suspended tray

supported by cranes , thereby presenting significant safety risks and severe manual handling issues to manoeuver pivot pins into position and then force pivot pins through or from openings in tray/truck pivot pin support members by means of a sledge hammer.

The currently-accepted standard industry method does not comply with Worksafe occupational and health

regulation 1996, clause 4.53 and a multitude of individual mine-site rules regarding working under suspended loads.

Moreover, where significant force is required to insert or remove pivot pins from tray/truck pivot pin support members, there can be damage caused to the

tray/truck pivot pin support members that has an adverse impact. SUMMARY OF THE DISCLOSURE

The device of the invention allows pivot pins to be inserted and removed to facilitate coupling and uncoupling of trays and rear tipping haul trucks in a method that is a safe and a reliable alternative to the above-described currently-accepted standard industry method.

In broad terms , the invention provides a device for inserting and removing pivot pins to facilitate coupling together and uncoupling a tray and a rear-tipping truck, the device being adapted to being mounted to the tray and aligned with openings in pivot pin support members of the tray, and the device including members that can be

inserted into and withdrawn from openings in tray/truck pivot pin support members and can couple together the tray and the truck when inserted into the openings so that the truck supports the tray.

With this arrangement, there is a mechanical

connection between the tray and the truck and safe

insertion of pivot pins (or removal of pivot pins in the revers operation) is not dependent solely on the crane supporting the tray and the tray is no longer classified as a suspended load.

In broad terms , the invention also provides a method of coupling together and uncoupling a tray and a rear- tipping haul truck includes the following steps:

(a) mounting the device defined in the preceding paragraph to the tray while the tray is on the ground or on other suitable support surface such that the members of the device are aligned with openings in pivot pin support members of the tray;

(b) lifting the tray to a position in which openings in pivot pin support members of the tray are aligned with openings in pivot pin support members of the truck for receiving pivot pins;

(c) extending the members into the aligned openings in the tray/truck pivot pin support members so that the truck supports the tray via the piston assembly and the tray is no longer classified as a suspended load;

(d) progressively inserting pivot pins into the aligned openings in the tray/truck pivot pin support members from an opposite direction to the direction of inserting the members and progressively withdrawing the piston assemblies as the pivot pins are inserted into the openings , such that the pivot pins replace the members and support the tray; and

(e) removing the device altogether.

The device may have oppositely facing hydraulic- actuated devices that can be aligned with openings in complementary tray/truck pivot pin support members on opposite sides of a tray of a rear-tipping haul truck.

More particularly, the invention may provide a device for inserting and removing pivot pins to facilitate coupling together and uncoupling a tray and a rear-tipping truck, the device being adapted to being mounted to the tray and aligned with openings in pivot pin support members of the tray, and the device including a pair of coaxial and oppositely facing hydraulic units having piston assemblies that include pistons that can be moved between retracted and extended positions and are adapted to being inserted into openings in tray/truck pivot pin support members.

The device may include a central shaft between the aligned and oppositely facing hydraulic units , with the hydraulic units being connected to opposite ends of the central shaft. The central shaft spaces apart the

hydraulic units.

Each piston assembly may include a piston and a dummy pin connected to an outer end of the piston. By way of example, the dummy pin may be adapted to be screw-fitted onto the piston.

An outer end of each dummy pin may be chamfered or otherwise formed to facilitate insertion of the dummy pin into openings in tray/truck pivot pin support members . The device may be constructed as a compact unit.

The device may be adapted to apply a maximum output force of at least 20, typically at least 30, and more typically at least 60 tonne to force out seized pivot pins to uncouple trays and haul trucks .

The device may be mounted to a new tray on the ground or on other suitable support surface prior to the tray being lifted into a position and supported as a suspended load in relation to the truck tray.

The device may include a controller that can actuate both hydraulic units (separately or together) .

The controller may be actuated remotely by a person standing outside a footprint of the tray when the tray is a suspended load in relation to the haul truck.

The device may include cameras that can be positioned on the haul truck and/or the tray to allow a clear view of the haul truck and the tray to assist in positioning the tray on the haul truck.

The invention also provides a method of coupling together and uncoupling a tray and a rear-tipping haul truck that is based on the use of the above-described hydraulic-actuated device.

The method of coupling together the tray and the haul truck may include the following steps:

(a) mounting the device to the tray while the tray is on the ground or on other suitable support surface such that the piston assemblies of the device are aligned with openings in pivot pin support members of the tray;

(b) lifting the tray to a position in which openings in pivot pin support members of the tray are aligned with openings in pivot pin support members of the truck for receiving pivot pins ;

(c) extending the piston assembly into the aligned openings in the tray/truck pivot pin support members so that the truck supports the tray via the piston assembly and the tray is no longer classified as a suspended load;

(d) progressively inserting pivot pins into the aligned openings in the tray/truck pivot pin support members from an opposite direction to the direction of inserting the piston assemblies and progressively

withdrawing the piston assemblies as the pivot pins are inserted into the openings , such that the pivot pins replace the piston assemblies; and

(e) removing the device altogether.

The invention also provides a tray of a rear-tipping truck, such as a rear-tipping haul truck and the above- described device mounted to an underside of the tray.

The piston assemblies of the device extend at least partially into and are retained within pivot pin support members of the tray. BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described further by way of example only with reference to the accompanying drawings , of which :

Figure 1 is a side view of one embodiment of a device for inserting and removing pivot pins to facilitate coupling together and uncoupling a tray and a rear-tipping haul truck used in the mining industry in accordance with the invention mounted to an underside of the tray, with parts of the device shown as being partly transparent to show internal components of the device, and with the device being in a retracted position;

Figure 2 is an enlarged side view of the device shown in Figure 1 ;

Figure 3 is a perspective view of the device shown in

Figure 2 ; and

Figure 4 is a side view of the device and the tray shown in Figure 1 mounted on clevises of a haul truck and with pivot pins inserted into the clevises .

DESCRIPTION OF EMBODIMENTS The invention provides a device for inserting and removing pivot pins to facilitate coupling together and uncoupling a tray and a rear-tipping truck. The device is adapted to being mounted to the tray and aligned with openings in pivot pin support members of the tray. The device includes members that can be inserted into and withdrawn from openings in tray/truck pivot pin support members and can couple together the tray and the truck when inserted into the openings so that the truck supports the tray. With this arrangement, there is a mechanical connection between the tray and the truck and safe

insertion of pivot pins (or removal of pivot pins in the reverse operation) is not dependent solely on the crane supporting the tray and the tray is no longer classified as a suspended load.

With reference to Figures 1 to 3, the embodiment of the device generally identified by the numeral 3 for inserting and removing pivot pins 5 to facilitate coupling together and uncoupling a tray 7 and a rear-tipping truck (not shown) , such as a rear-tipping haul truck used in the mining industry, in accordance with the invention shown in these Figures includes :

(a) a central shaft 15,

(b) a pair of aligned and oppositely facing hydraulic units 9 extending from opposite ends of the central shaft

15, with the hydraulic units 9 having pistons 11 that can be moved between retracted and extended positions , with each hydraulic unit 9 being connected to an end of the central shaft 15, and

(c) a dummy pin 17 connected to an outer end of each piston 11.

Basically, the device includes two double acting hydraulic units 9 mounted back-to-back and separated by a central shaft 15 and dummy pins 17 connected to the pistons 11 of the hydraulic units 9.

The pistons 11 and dummy pins 17 form piston

assemblies . The piston assemblies further include outer shrouds 33 in the form of sleeves that protect the pistons 11 and dummy pins 17.

The piston assemblies further include quick connect hose couplings 39 to connect the hydraulic units 9 to a suitable source of hydraulic fluid.

An outer end of each dummy pin 17 is chamfered to facilitate insertion of the dummy pin 17 into an opening in an inner pivot ear of a pair of pivot ears 23 that form a pivot pin support assembly of the tray 7.

The device 3 is compact and typically weighs around 150kg.

The device 3 also includes a controller (not shown) that can actuate both hydraulic units 9 (separately or together) . The controller may be actuated remotely by a person standing outside the footprint of the tray 7 when, in use, the tray is suspended via cranes above the ground.

The device 3 also includes cameras 25 that are positioned on the tray 7 to allow a person to have a clear view of the haul truck and the tray 7 as the tray 7 is being manoeuvred into a required position in relation to the haul truck.

Whilst not critical to the invention, from a context perspective it is noted that, typically, a tray 7 for a haul truck has a life of 50,000 hours and may be removed from a haul truck 3-4 times in this lifetime.

The device 3 is intended to be used across a range of different types of trays of different manufacturers.

Typically, each tray type has different spacings between tray pivot ears and also different pivot pin diameters. The device 3 accommodates these variations in tray types by means of a parts kit for each tray 7 , enabling economy through re-using major hydraulic components and camera equipment and, hence, manufacturing a designated parts kit for each tray to cope with the variance of offsets across the tray range.

In use of the device 3 shown in Figures 1 to 4 to couple together a tray 7 and a haul truck, while the tray 7 is on the ground, the device 3 is positioned via a movable support jig (not shown) so that the dummy pins 17 of the device 3 are aligned with the openings in the inner pivot ears 23 on opposite sides on the tray 7. The structure of the support jig may be any suitable structure and does not form part of the invention. The centreline through the openings in the inner pivot ears 23 is the pivot axis of the tray 7. Chains or other suitable support members (not shown) are used to connect the device 3 to the tray 7 with the device 3 in the aligned position. The dummy pins 17 are extended by actuating the hydraulic units 9 of the device 3 to move the ends of the dummy pins 17 outwardly at least partially into the openings in the inner ears 23, thereby further connecting the device 3 to the tray 7. The tray 7 , with the device connected to the tray 7 , is then moved via a crane (not shown) into a position in which the openings of the pivot ears 23 of the tray are aligned with the openings in the complementary pivot pin support members on the haul truck (shown as clevises 37 in Figure 4 - and which define the pivot axis of the truck) . More specifically, with reference to

Figure 4 and the Figure in the description of step 4 below, the tray is positioned on the truck clevises 37, with the clevises occupying the spaces between the pivot ears of the pairs of pivot ears 23. During this step, the person operating the hydraulic units 9 of the device 3 is clear of the tray footprint and can observe via the cameras 25 the movement of the tray 7 and can provide instructions to the crane operator while in a safe

position to assist the crane operator positioning the tray 7 in relation to the haul truck. When in the required position, with the tray 7 mounted on the truck clevises 37 , and with the openings in the pivot ears 23 on the tray 7 and the openings in the truck clevises 37 on the haul truck aligned, the dummy pins 17 are extended further outwardly via operation of the pistons 11 to be positioned at least partially in the openings in the truck clevises 37 of the haul truck. This step moves the tray 7 from being a suspended load via the crane to a supported load via the truck clevises 31 of the haul truck. The

supported load position is a safer position than the suspended load position. At this point, a person can safely move to be within the footprint of the tray 7 and push a pivot pin 5 into the opening in the outer pivot ears of each pair of pivot ears 23 on the tray 7 and then into the aligned opening in the associated truck clevis 37 until the pivot pin 5 abuts the end of the dummy pin 17. The next step involves continuing to move the pivot pins 5 inwardly while withdrawing the dummy pins 17 so that the pivot pins 5 progressively displace the dummy pins 17, with this step including retracting the dummy pins via operation of the hydraulic units 9. During this step, the tray 7 remains in a supported load position, increasingly supported via the pivot pins 5 rather than via the dummy pins 17.

The reverse procedure is followed to remove a tray 7 from a haul truck.

The operational sequence of steps to couple together a tray 7 and a haul truck and to uncouple the tray 7 and the haul truck are described in more detail below with reference to the Figures that form part of each described step and with reference to Figures 1 to 4. It is noted that the following Figures that form part of the

description of each step do not include reference

numerals. Having made this point, it is noted that the following Figures are based on Figures 1-4 and the

reference numerals used in these Figures identify the same features in the following Figures .

Tray Positioning Operational Steps Step 1 - Positioning camera 25 and device 3 on tray 7.

• Connect LHS and RHS cameras 25 to outer ends of the tray 7 looking concentrically through the openings in the pivot ears 23 of the tray 7.

• Position the device 3 on a movable support jig (not shown) and move the jig until a central axis of the device 3 is coarsely aligned (i.e. +/-10mm) with the tray pivot axis.

• Connect the device 3 to the underside of the tray 7 in this aligned position with suspension chains (not shown) .

Step 2 - Centralize the device 3 with shim spacers .

• Shim Spacers 35 (not described above but shown in Figures 2 and 3) are positioned to centralize the device 3 relative to the tray 7 typically within 5 mm but still permitting the dummy pins 17 to pass through. The shim spacers 35 are adapted to be dropped into location spigots (not shown) on the outer shrouds 33.

Step 3 - Extend both pistons partially.

• Extend both pistons 11 partially until the dummy pins 17 sit within the inner pivot ears of the pairs of pivot ears 23 and further connect the device 3 to the tray 7. The device is now fully aligned with the pivot axis of the tray 7 and securely connected to the tray 7.

• Remove movable support jig, as the device 3 is now self-supporting via the dummy pins 17 extending into the inner pivot ears and the back-up suspension chains securing the device 3 to the underside of the tray 7.

Step 4 - Lift tray into position

• Utilizing the cameras 25 located at opposite ends , guide the crane to lower the tray onto the truck clevises 37 , with the clevises defining the pivot axis of the truck.

• Once the pivot axis of the tray 7 is within +/-10mm of the pivot axis of the truck, the dummy pins 17 are extended further via the hydraulic units 9 beyond the inner pivot ears of the pairs of pivot ears 23 to interengage the tray 7 and the truck clevises 37.

Step 5 - Engage dummy pins

• When fully extended as shown, the dummy pins 17 are engaged and the tray 7 is supported by the truck via the truck clevises 39. The tray 7 is no longer classified as a suspended load.

• Service personnel can now safely enter the space

under the tray footprint and prepare for fitting the pivot pins 5.

Step 6 - Pivot pin insertion

The cameras 25 are removed from both ends and the pivot pins 5 are manually inserted inwardly from both sides until coincident with the face of the dummy pins 17. Step 7 - Dummy pin retraction and pivot pin insertion.

• The dummy pins 17 are retracted via operation of the hydraulic units 9 and, simultaneously the pivot pins 5 are pushed into the final positions manually.

• When the dummy pins 17 are retracted to be clear of the inner ears of the pairs of ears 23, the tray 7 is mounted for pivoting movement to the truck via the pivot pins 5 and the device 3 is mounted to the tray 7 solely by means of the suspension chains .

• The device 7 is then taken away .

Tray Removal Operational Steps

In essence, this process is the reverse of the fitment process .

Step 1 - Position and mount device to underside of tray body

• Position the device 3 on the underside of the tray 7 with the moveable support jig aligning the pivot axis of the device 3 with the pivot axis of the pivot pins 5 to be within +/-5mm.

• Connect suspension chains to the underside of the

tray 7 to connect the device to the tray 7.

Step 2 - Check alignment and insert shim spacers

• Insert shim spacers 35 to center the device 3. Step 3 - Extend dummy pins

• Extend the dummy pins 17 incrementally into and

through the inner ears of the pairs of ears 23 via the operation of the hydraulic units 9 until the pivot pins 5 are dislodged outwardly from the pivot ears 23 and the truck clevises 37.

• Fully stroke out' the dummy pins 17 and leave

extended so that the tray 7 is supported on by the truck via the dummy pins 17. Step 4 - Fully remove Pivot pins

Fully remove pivot pins 5 from both ends .

Connect crane chains to the tray 7 and remove all personnel from footprint area of the tray 7.

The crane operator raises the lift point until slack in the chains has been removed.

5 - Retract dummy pins and release tray

Operate the hydraulic units 9 to fully retract the dummy pins clear of the inner ears of the pairs of ears 23.

Assuming the hydraulic units 9 have been

disconnected, the tray 7 can now be lifted clear with the device 3 still connected to the tray 7. • The suspension chains will not permit the device 7 to drop but the device 7 should be primarily contained by leaving the dummy pins 17 partially engaged in the inner pivot ears 23.

· The device 3 can be removed once tray 7 is placed on ground.

The applicant has found that the device described above in relation to the Figures operates effectively and provides a safe and reliable alternative to the current practice .

Many modifications may be made to the embodiment described in relation to the Figures without departing from the spirit and scope of the invention.

By way of example, whilst the embodiment described in relation to the Figures includes a pair of coaxial and oppositely facing hydraulic units having piston assemblies that include pistons, the invention extends to any

suitable devices that include members that can be inserted into and withdrawn from openings in tray/truck pivot pin support members and can couple together the tray and the truck when inserted into the openings so that the truck supports the tray .

By way of further example, the applicant has

developed frames for fixing the device to trays 7. The purpose of these frames is to lift a device 3 into place with a forklift so the device 3 can be taken down from a fitted tray 7 without the need for manual handling.

By way of further example, whilst the embodiment described in relation to the Figures includes cameras 25 that are positioned on the tray 7 to allow a person to have a clear view of the haul truck and the tray 7 , it can readily be appreciated that the invention is not limited to the use of cameras .

By way of further example, whilst the embodiment described in relation to the Figures is described as being a compact device 3 that typically weighs around 150kg, the invention is not so limited and extends to any suitable shape and weight.

By way of further example, whilst the embodiment described in relation to the Figures is described as a rear-tipping haul trucks used in the mining industry, the invention is not limited to this type of truck and extends generally to rear-tipping mining and earth moving trucks.

By way of further example, the invention is not limited to a particular tray capacity and is equally applicable to small and large capacity trays . For

example, the invention is equally applicable to trays used in the mining industry that range in size from 50-60m ³ weighing 10-12 tonne and up to and more than 300m ³ weighing in excess of 45 tonne, and in some instances up to 60 tonne . By way of further example , earth moving trucks in civil construction applications are typically smaller capacity trays, weighing 6-8 tonne.