AU2017204158A1 - Improvements in devices for loading, transporting and unloading cargo - Google Patents

Abstract

A device (10) for loading, transporting and unloading cargo (200) including a pair of chassis sides (12, 14), each chassis side including main wheels (110) supporting the device, and a protrusion (150) for engaging with a cargo to be loaded, transported and unloaded, the device further including a link mechanism (36, 38) for expanding and contracting the device by moving the chassis sides (14, 16) towards and away from each other to enable the device to be positioned on either side of a load (200) in an expanded state and subsequently contracted to engage with the load wherein the link mechanism is located above the load in use and is a cruciform linkage comprising two link members (36, 38) of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together, and wherein two transverse wheels (152) are mounted to the rear of each chassis side at the base of the chassis structure for allowing the chassis sides to move laterally when the main wheels are raised above the ground wherein the transverse wheels (152) are arranged such that they are unable to rotate in the same clockwise or anticlockwise direction.

Description

"Improvements in devices for loading, transporting and unloading cargo" Cross-Reference to Related Applications [0001] The present application claims priority from Australian Provisional Patent Application No 2016902552 filed on 29 June 2016, the content of which is incorporated herein by reference.

Technical Field [0002] This invention relates to a device for loading, transporting and unloading cargo, particularly, but not exclusively for carrying unitised or modularised loads.

Background [0003] Straddles are used to move loads in ports prior to loading them onto ocean going vessels, barges or the like. A typical straddle includes an inverted U shaped frame and a means for lifting and suspending a load such as a shipping container or unitised or modularised load from the frame. One type of modularised load which are commonly moved by straddles is aluminium ingots. For transport from a smelter to an end user, the aluminium ingots are set together in bundles, each of which weighs approximately one tonne. These bundles are held together by straps. Typically, a number of such stacked bundles are then consolidated together making up a shipping pack, often known as a "Superpack". The Superpack may be made up of any number of two high bundles consolidated together and may weigh 24 or up to 36 tonnes. These Superpacks are typically transferred from the smelter to a port by road on a flatbed truck. Once the trucks reach port they are unloaded and stored prior to transfer to dockside for transfer to an ocean going vessel or barge by a crane having an appropriate spreader attachment. The Superpacks can be unloaded from the truck and moved into a storage area by straddle carrier. Subsequently the straddle carrier loads and transfers the Superpack to dockside for loading onto an ocean going vessel.

[0004] The process including the use of straddle carriers in particular has a number of disadvantages. First, the overall process of moving the ingots from the smelter to an ocean going vessel is relatively inefficient as it involves a number of separate operations of loading and unloading, and transport and storage by different types of equipment. The operation would be improved both economically and operationally if it were possible to utilise one equipment type for the loading, transporting and unloading of the cargo. This approach would also reduce the number of handling movements in the logistics chain making it more efficient and safer.

[0005] Secondly, straddles are not very compact. When they are used to transport and move loads to storage, those loads have to be stored sufficiently far apart to allow the straddle to move between loads to pick up and transport the load to dockside. Thus the storage ratio of load area to floor space is poor using straddles.

[0006] Straddles also have a high capital cost and are expensive to maintain and run.

[0007] International Patent Application WO 2010/048674 to the same applicant as the applicant for this provisional application (the entire content of which is hereby incorporated by reference) addresses this problem by providing a trailer/device for which can load transport and unload cargo. The trailer includes a pair of chassis sides, each chassis side including wheels supporting the device, and a protrusion for engaging with a load to be picked up and transported. The trailer further including a link mechanism for expanding and contracting the device by moving the chassis sides towards and away from each other to enable the device to be positioned on either side of a load in an expanded state and subsequently contracted to engage with the load. The link mechanism is located above the load in use and is a cruciform linkage comprising two link members of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together. Because the chassis sides themselves move inwards and outwards the trailer can be more compact than a traditional straddle. The trailer can also be registered and utilised on most country’s public roads systems. In particular, once loaded, the trailer’s width is approximately 2.5 meters which corresponds to most countries’ public road width limitations.

[0008] The present invention is directed to improvements to the trailer disclosed in WO 2010/048674, and in particular to improvements which improve the reliability of the device and also may increase its suitability for use on public roads.

[0009] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present 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 present invention as it existed before the priority date of each claim of this application.

Summary [0010] In a first aspect of the present invention, there is provided a device for loading, transporting and unloading cargo including a pair of chassis sides, each chassis side including main wheels supporting the device, and a protrusion for engaging with a cargo to be loaded, transported and unloaded, the device further including a link mechanism for expanding and contracting the device by moving the chassis sides towards and away from each other to enable the device to be positioned on either side of a load in an expanded state and subsequently contracted to engage with the load wherein the link mechanism is located above the load in use and is a cruciform linkage comprising two link members of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together, and wherein two transverse wheels are mounted to the rear of each chassis side at the base of the chassis structure for allowing the chassis sides to move laterally when the main wheels are raised above the ground wherein the transverse wheels are arranged such that they are unable to rotate in the same (clockwise or anticlockwise) direction.

[0011] Typically the device will be a trailer which is mounted on a prime mover or tow motor turntable or the like. This arrangement allows the transverse wheels to be used to assist with the opening and closing of the rear end of the device. Preventing them from rotating in the same (e.g. clockwise) direction, stops the device as a whole from pivoting about the turntable down an incline where the yard or ground on which the device is being used slopes.

[0012] In a preferred embodiment the transverse wheels include a ratchet system arranged so that unless the ratchet is disengaged the wheels are prevented from moving in the same (clockwise) direction.

[0013] It is preferred that the ratchet arrangement limits the distance the transverse wheels are able to travel along the ground, typically to about 200 to 300mm, most preferably about 250mm.

[0014] It is preferred that transverse wheels are provided at the front of the trailer, as well as at the rear. In a preferred embodiment the mounting is via a plate to which a stub axle is mounted, the plate having offset bolt holes to allow for height adjustment.

[0015] In the device because the chassis sides themselves move inwards and outwards to pick up the load, the device can be more compact than say a traditional straddle in which there is a frame having a fixed width supporting a clamping and lifting apparatus inside the frame.

It is preferred however that means in addition to the link mechanism are provided for opening and closing the chassis sides.

[0016] Thus in a preferred embodiment, additional hydraulic cylinders are provided which extend transversely between the chassis sides for assisting in opening and closing the device. Typically additional hydraulic cylinders are provided at the front and rear of the trailer/device at or towards the bottom of the device. At the rear it is preferred that a further hydraulic cylinder is provided at the top of the device, which is phased with the lower cylinder and opens and closes in sync with the lower cylinder.

[0017] The lower rear cylinder is preferably pivotally mounted at the base of one chassis side so that it can pivot upwardly from a deployed position to a vertical position through about 90° for loading and unloading of the device/trailer. Typically the distal end of the piston rod which locates in the hydraulic cylinder will be enlarged and will engage behind a slot when in the deployed position.

[0018] Thus in a second aspect of the present invention, there is provided a device for loading, transporting and unloading cargo including a pair of chassis sides, each chassis side including main wheels supporting the device, and a protrusion for engaging with a cargo to be loaded, transported and unloaded, the device further including a link mechanism for expanding and contracting the device by moving the chassis sides towards and away from each other to enable the device to be positioned on either side of a load in an expanded state and subsequently contracted to engage with the load wherein the link mechanism is located above the load in use and is a cruciform linkage comprising two link members of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together, and wherein one or more additional cylinders extend between the chassis sides for assisting in opening and closing the device.

[0019] In a preferred embodiment, gates are provided for closing the rear of the device. It is preferred that the gates open and close in a vertical plane.

[0020] Thus in a third aspect of the present invention, there is provided a device for loading, transporting and unloading cargo including a pair of chassis sides, each chassis side including main wheels supporting the device, and a protrusion for engaging with a cargo to be loaded, transported and unloaded, the device further including a link mechanism for expanding and contracting the device by moving the chassis sides towards and away from each other to enable the device to be positioned on either side of a load in an expanded state and subsequently contracted to engage with the load wherein the link mechanism is located above the load in use and is a cruciform linkage comprising two link members of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together, and wherein a gate assembly is provided at the rear of the device [0021] In the device, it is necessary to raise and lower the main wheels relative to the transverse wheels, to allow the chassis sides to be moved apart and together to load or unload cargo. In a preferred embodiment a grab rail is defined at the base of each chassis side which defines a horizontal flange or shelf/ledge which juts toward the centre of the device and on which the load is supported in use.

[0022] In a preferred embodiment the main wheels are mounted on support legs connected to cylinders allowing the wheels to be raised and/or lowered relative to the base of the device and wherein the lower end of the support leg is mounted to the base of the trailer via a vertically extending pin which is mounted on and extends upwards from the base of the trailer. Typically the lower part of the support leg defines a slot and the pin fits in bushes mounted within the slot in the support leg. The pin allows vertical movement of the leg along the pin. In one embodiment, the mounting of the pin in the slot may permit rotational movement of the leg about the vertical axis of the pin.

[0023] In a preferred embodiment moveable gates are provided part way along the chassis sides which, when deployed, extend inwards

Brief Description of Drawings [0024] Specific embodiments of the invention will now be described, by way of example only and with reference to the accompanying drawings in which:-

Figure 1 is a side view of a trailer embodying the present invention;

Figure 2 is a top plan view of the trailer of Figure 1;

Figure 3 is a schematic view illustrating the rear of the trailer showing a rear transverse/dolly wheel;

Figures 4a to 4c show the dolly wheel of Figure 3;

Figure 5 is a schematic view of the rear of the trailer illustrating rear opening and closing cylinders and a rear gate;

Figure 6 is a schematic view of the front of the trailer illustrating a front opening and closing cylinder;

Figures 7a and 7b are rear views of one chassis side illustrating a lower closing cylinder; Figures 8a to 8e illustrate views of the cylinder in up or down configurations;

Figures 9a and 9b are schematic views illustrating the operation of the rear gate of the trailer; Figures 10a to 10c show a front transverse/dolly wheel of the trailer;

Figure 11 shows a leg guide pin on which the main wheels are mounted in situ',

Figures 12a and 12b are views of the leg guide pin;

Figure 13 is a schematic diagram illustrating a hydraulic locking mechanism;

Figure 14 is a schematic diagram of the trailer from above showing the trailer with a load of ingots located between the sides of the chassis ready to be loaded;

Figure 15 is a schematic diagram of the trailer from above showing the trailer in a closed mode with a load of ingots carried between the sides of the chassis;

Figure 16 is a schematic diagram of a hydraulic circuit of the trailer; and

Figure 17 shows an isometric view of a variant of the trailer from the end and the right side, illustrating in particular a moveable gate; and

Figure 18 is a detailed view of the gate;

Description of Embodiments [0025] Referring to the drawings, Figures 1 and 2 show a device for loading, transporting and unloading cargo in the form of a trailer 10 whose front end may be turntable mounted to a truck/ prime mover or tow motor (not shown).

[0026] The trailer 10 includes two chassis sides, a left hand chassis side 12 and a right hand chassis side 14, as viewed from the rear of the trailer. Each chassis side includes an upper beam assembly, being left hand and right hand beam assemblies 16 and 18 respectively. The front end of the right beam assembly is pivoted about a vertical axis to one (proximal) end of a right scissor link in the form of a right hand link beam 20. The front end of the left beam assembly is pivoted about a vertical axis to one (proximal) end of a left scissor link in the form of a left hand link beam 22 which is also 1750mm long. The distal ends of the two links 20, 22 are pivotally linked about a vertical axis at 24.

[0027] Also pivoted about the same vertical axis is a chassis link and mounting assembly generally shown at 25 for connecting the trailer 10 to a prime mover. There are two hydraulic cylinders 26 and 27 each of which extends from the assembly to the ends of a respective scissor link 20, 22 adjacent where the link is pivoted to one of the chassis beams.

[0028] The assembly 25 includes a link 28 which is mounted for vertical rotation about axis 24 at its upper end. A further link 30 extends from the lower end of link 28. A turntable plate 32 for engagement with the prime mover is mounted to the link 30. A hydraulic cylinder assembly 34 extends between the link 28 and link 30 adjacent the turntable plate 32. As will be described in more detail below in relation to operation of the trailer, the cylinder and chassis link and mounting assembly may be used to vary the height of the front of the trailer chassis during loading.

[0029] The chassis sides 12 and 14 are linked by a cruciform linkage best seen in Figures 2, 14 and 15. The linkage includes a first link member in the form of a simple beam or strut 36 and a second link member in the form of a compound strut 38. One end of the simple strut 36 is pivoted to the left hand chassis side 12 adjacent the rear end of the trailer about a vertical axis 40. The other end of the simple strut defines a depending pin 42 which locates in a slot 44 defined in a plate 46 attached to the top of the right hand beam assembly 18 towards the front of the trailer. The compound strut is made of two relatively shorter beams 48, 50. A gap 52 is defined between the opposed ends of the beams which are linked by upper and lower plates. The simple strut passes through the gap 52 and is fixed to the plates by a pin defining a vertical pivot axis 58 half way along its length. In a mirror arrangement to that of the simple strut, one end of the compound strut 36 is pivoted to the left hand chassis side 14 adjacent the rear end of the trailer about a vertical axis 60. The other end of the simple strut defines a depending pin 62 which locates in a slot 64 defined in a plate 66 attached to the top of the left hand beam assembly 18 towards the front of the trailer.

[0030] The link members 36 and 38 are pinned together, halfway along their overall length at pivot 58. The longitudinal axes of the left hand side scissor link and compound strut 38 are parallel to each other as are the longitudinal axes of the left hand side scissor link 22 and the simple strut 36. The vertical pivots of the struts 36 and 38 and the scissor links 20 and 22 are located on the central longitudinal axis of the trailer 10. As set out above, the ends of the cruciform links 36 and 38 adjacent the rear of the trailer are pinned to the chassis. The opposite ends are able to slide in the slotted plates of the chassis side beams. This geometry expands the trailer width such that the sides 12 and 14 remain parallel to each other.

[0031] Hydraulic cylinders 68 and 70 are provided for pushing and pulling the end of each strut along its respective slot. Both sides of each cylinder 68, 70 are connected to a single hydraulic valve so that both cylinders are lengthened or shortened simultaneously.

[0032] A short explanation of the geometry of the cruciform linkage will now be provided, with reference to Figures 14 and 15 in particular.

[0033] As discussed above, the link members 36 and 38 are pinned together, halfway along their overall length at pivot 58. From Figure 6 it can be seen that the half length dimension of each strut of the cruciform linkage is 1750mm long measured from the respective mounting on the chassis side to the pivot 58. The left and right scissor links are each 1750mm long.

The longitudinal axes of the left hand side scissor link and compound strut 38 are parallel to each other as are the longitudinal axes of the lefthand side scissor link 22 and the simple strut 36. The vertical pivots of the struts 36 and 38 and the scissor links 20 and 22 are located on the central longitudinal axis of the trailer 10. As set out above, the ends of the cruciform links 36 and 38 adjacent the rear of the trailer are pinned to the chassis. The opposite ends are able to slide in the slotted plates of the chassis sides beams. This geometry, expands the straddle trailer width such that the sides 12 and 14 remain parallel to each other, as illustrated in Figures 14 and 15, where Figure 15 shows the trailer fully expanded.

[0034] A hydraulic braking system is provided for locking the link mechanism and preventing opening of the link mechanism. This system is shown schematically in Figure 13. The system will be described with reference to the brake on the right hand side of the chassis only, the brake on the left hand side being identical to that on the right.

[0035] With reference to Figure 13 the slotted plate 46 includes two identical slotted plates 46a and 46b one above the other. As referred to above, the pin 42 at the end of the link 36 is located and movable along slot 44 by means of hydraulic cylinder/ram 68. In theory, locking the hydraulic cylinder should lock the cruciform linkage in position and prevent the linkage opening. However, as the trailer is intended to carry loads in excess of 20 tonnes, an additional robust braking system to lock the linkage is desirable. As shown in Figure 5, the braking system 80 is carried on the pin 42 and includes a top cap 82, a first brake disc 84 located above the plate 46a, a second brake disc 86 located below the plate 46a, a third brake disc 88 located above the lower plate 46b separated from the second disc by a gap 90, and a fourth brake disc 92 located below the lower plate 46b. A lower end cap 94 encloses the lower part of the brake disc 92, and a cylindrical housing 96 partly encloses the second and third brake discs and the gap between them. O-ring seals are provided adjacent the open ends of the caps and cylinder. As well as the gap 90 between the second 86 and third brake discs 88, a gap 98 exists between the first end cap 82 and the first brake disc 84, and a further gap 100 exists between the lower end cap 94 and the fourth brake disc 92.

[0036] The pin 42 defines a central longitudinal bore 102. The pin defines a series of channels 104, 106, 108 extending from the central bore to each of the gaps 98, 90 and 100, respectively. The bore is connected to the trailer's hydraulic circuit to be described in more detail below. It will be appreciated that hydraulic fluid passing from the bore 102 into the gaps will force the brake discs against the upper and lower surfaces of the upper and lower plates 46a and 46b, thus preventing opening (or closing of) the link mechanism when the brake is on. The brake also alleviates potential wear problems in the slots 44 by reducing movement and wobble.

[0037] It should be noted that while the braking mechanism as described uses four brake discs acting on two plates on each chassis side, it would be possible to have a single plate sandwiched between just two brake discs on each chassis side.

[0038] As shown in Figure 1, the trailer has three main wheel assemblies 110 on each side (although a larger trailer for carrying heavier loads might have four wheels on each side). Each wheel assembly includes a large single tyre 112 of a size and type commonly used on trailers. The width of the tyre is such that the tyre fits beneath the chassis beam, adjacent the load. The hubs of each wheel assembly are mounted to the base of an inverted L-shaped wheel support leg 114, best seen in Figures 1 and 11. Each support leg 114 is mounted to a steering and suspension cylinder rod 116 which is part of a suspension cylinder assembly 118 (hidden in Figure 1 behind a removable cover 120 which is removable to allow access to the cylinder for repair or replacement). Figures 11 to 12b illustrate the mounting of the support leg to the base of the trailer, which is described in more detail below.

[0039] Each of the three suspension cylinders 118 on their upper side 118a have their load connected to a single hydraulic accumulator 120 charged with nitrogen gas (refer to the hydraulic circuit diagram - Figure 16). The suspension system shares the load equally to each tyre, on each side. The three cylinders 118 are also connected to a hydraulic valve. The upper suspension cylinder cavity 118a is the pressure cavity, which supports the load to each wheel and tyre.

[0040] The lower suspension cylinder cavities 118b of all three cylinders on both sides are also interconnected and connected to a single hydraulic valve 124. When the trailer is carrying a load, or is travelling empty, the lower cylinder cavities 118b are open through the valve, to the hydraulic reservoir 126.

[0041] In some embodiments, the wheels of the trailer can be steered for allowing the trailer and prime mover to make tighter turns and improve manoeuvrability which is important in a dockside environment where space can be limited.

[0042] Referring to Figures 3, 5 and 7b it can be seen that an inwardly directed protrusion or grab rail in the form of an angle iron bar 150 is defined towards the base of each chassis side 12, 14. Each bar 150 extends along substantially the entire length of each chassis. As is best seen in Figure 7b, when the wheels of the trailer are at a height for driving the trailer, the bars are at approximately the same height as the lowest part hubs of the main wheels. Also shown in Figure 3, are two smaller wheels 152 (rear transverse loading wheels/dolly wheels). As is best seen in Figure 2, the lowermost part of the transverse wheels 150 are below the base of the angle iron bars/grab rails 150.

[0043] Transverse wheels 202 are also provided at the front of the trailer (see Figure 6).

With reference to Figures 10a to 10c, these are mounted on plates 204, each of which defines four bolt holes, with an offset from the bolt holes to the axle by four different distances. This allows for four different height position adjustments.

[0044] Figures 11 to 12b illustrate the mounting of the support leg to the base of the trailer which is via a vertically extending pin 250 which extends from an integral plate 254 which is mounted on, and extends upwards from, the base of the trailer adjacent the grab rail 150. It can be seen that the lower part of the leg 114 defines a slot and the pin fits in bushes 252 mounted within the leg. The pin 250 allows vertical movement of the leg along the pin 250, but not rotational movement.

[0045] In an alternative embodiment the pin 250 may be replaced by the pin 256 shown in Figures 12a and 12b which allows for limited rotational movement of the leg about the vertical axis of the pin. It can be seen that the pin 256 is mounted in a slot 260 defined in the mounting plate 258 which slot permits a small arc of movement of the pin in the plate, to allow for turning of the main wheels of the trailer.

[0046] Figure 16 is a schematic diagram of the hydraulic circuit of the trailer. While much of the diagram is self-explanatory, it is to be noted that the hydraulic pressure caused by the weight of the trailer and any load it carries is transmitted to the two brakes 80 which lock the cruciform link mechanism. This positive feedback means that the heavier the load carried, the greater the braking force which locks the cruciform linkage.

[0047] Turning now to Figures 3 to 4c, these Figures illustrate the rear dolly wheels (transverse wheels) 152 which are mounted to the chassis sides and a ratchet actuator arm 180. Figure 3 shows one dolly wheel on the right hand chassis 12. The arrangement on the left hand chassis 14 is a mirror image. There is a hydraulic cylinder 182 connected between the chassis side 12 and head of the piston extending from that cylinder is connected to the ratchet arm. In the closed position shown in Figure 3, the cylinder is vented and the piston is retracted into the cylinder. As hydraulic fluid is pumped into the cylinder the piston extends and the finger 186 of the ratchet arm 180 engages with the steeper slope of the teeth on the ratchet wheel fixed to the dolly wheels and rotates the dolly wheel to open the trailer. Movement stops when the piston is fully extended out of the cylinder. In that position the sides move outwards by 250mm. The arrangement on the left hand chassis 14 is a mirror image. This prevents the sides sliding in the same direction when the trailer is on a slope. Closing of the chassis sides in achieved using the closing cylinders as discussed below, and the ratchet mechanism freewheels in the closing direction with the finger clicking and sliding over the gently sloped side of the teeth.

[0048] With reference to Figures 5 to 8e, opening and closing of the trailer is assisted by cylinders connected between the two chassis sides 12, 14 of the trailer. A front closing cylinder 206 is mounted between the two front transverse wheels 202.

[0049] The front closing cylinder 206 is a phasing type cylinder. There is a second phasing type cylinder 208 (upper rear closing cylinder) which is phased to travel in and out in sync with the front closing cylinder which extends between the top of the chassis sides at the rear of the trailer as is best seen in Figure 5.

[0050] There is an additional lower rear closing cylinder 210 which extends between the bottom of the chassis sides at the rear of the trailer as is best seen in Figures 5 and 7 to 8e. When raised, the lower rear closing cylinder includes a linkage with two springs, such that the springs keep the captive roller 232 against the upper end of the slot 234. The cylinder is foreshortened by hydraulic pressure and the captive roller remains at the far end of the captive slot, resulting in the cylinder swinging down, due to the linkage 235 being pivoted at the RH lower chassis, above and to the LH side of the cylinder pivot. The springs only assist with keeping the captive roller at the far end of the slot, until the cylinder has engaged the rod 214 and the circular plate 212 behind the plate 220 at the bottom of the LH chassis side 12. Then as the cylinder is further shortened by hydraulic pressure, the cylinder pulls the chassis sides together to the fully closed position. In doing this, the captive roller moves to the position shown in 8e, and the closing assist springs are fully compressed. Opening the lower rear cylinder with hydraulic pressure, allows the captive roller to travel to the end of the captive slot, while the cylinder remains horizontal. Further extension of the cylinder with hydraulic pressure, lifts the cylinder as the linkage 235 pivots at the RH lower chassis, above and to the RH of the cylinder pivot pin. When the cylinder is fully extended by hydraulic pressure, then it is in the vertical position 8a and 8b, and is up to open to load, or unload.

[0051 ] The lower cylinder provides additional security against loss of load or accidental opening of the trailer as well as assisting in the closing of the chassis sides.

[0052] As is best seen in Figures 8a to 8e, the linkage includes a spring loaded rod which is connected to a captive roller 232 which is constrained to move in a slot 234. The rod is spring loaded to keep the captive roller in the end of the slot so that as the lower cylinder piston rod locates in the slot 220. Once in the slot the lower cylinder can continue closing.

[0053] The provision of the cylinders extending between the chassis sides assists in the opening and closing of the trailer to load and unload cargo, and also to maintain the side chassis in the closed position so that the load remains clamped by the chassis sides and supported on the rail 150.

[0054] To further increase the security of the load carried by the trailer, rear gates are provided as shown in Figure 5 and Figure 9a. As shown in Figure 9a, one end of a rod 300 is anchored to the upper side chassis. The other end of the rod is connected to a bell crank 302 mounted on the upper left hand chassis. The bell crank is linked to via a link member 304 to an upper member of a left hand gate 306 which it itself linked to a lower member 308 by a vertically extending link 310. Both members 306 and 308 are pivotally mounted to the left hand chassis side 14. A similar linkage operates the right hand side gate, noting that the rod connected to the left hand chassis 14 is omitted for clarity. The two rods cross with a front to rear lateral offset. There are a pair of compression springs where the rod 300 is mounted to the right chassis side 12 that allow for the inertia acceleration forces to be absorbed as the gates are actuate during opening and closing. It will be appreciated that as the chassis sides are moved apart, the bell cranks pivot and the left and right side gates move vertically upwards.

[0055] As shown in Figure 9b, there is a further pair of mid gates 350, 352 which swing about a vertical axis shown in Figure 9b. These are intended to catch any ingots that may become detached from the top of the “S uperpack” being carried by that trailer. When open the gates rotate through 90° until they are parallel to the chassis sides. As shown in Figure 9b there is a further lower closing cylinder shown which works in the same way as the cylinder 210 shown in Figures 5 and 9a.

[0056] In a variant illustrated in Figures 17 and 18 the chassis sides define a longitudinal slot 400 on the side that faces the load 200 which defines a series of bolt holes. Each side has a gate 404 slidably mounted in one of the slots 400 with a hydraulic cylinder 406 attached between the mountings 402 . The gates can slide along the slot and be locked in one of four set positions using the bolt holes to cater for various size loads. As described above in the case of cylinder 206, the cylinder 406 can be used to assist in opening and closing of the trailer. The gates 402 assist in safety in retaining the load in the trailer.

[0057] Use of the invention will now be described with particular reference to Figures 14 and 15. It is to be noted that in the lower diagram the trailer has a width of 3000mm. However, when closed and loaded as illustrated in Figure 6, the trailer has a width of 2500mm which is a legal width for use on public roads in most countries. The invention will be described in terms of loading a "Superpack" or ingot pack of Aluminium ingots, although it will be appreciated by the skilled person that other loads may be carried by the trailer, including custom built pallets upon which loose cargo can be placed.

[0058] As discussed above, the prime mover hauling the trailer typically includes a seat and controls that swivel the operator through 180°, allowing full and comfortable viewing of the Trailer during operation, when reversing. To load a Superpack or other cargo, the cruciform link is expanded by lengthening the hydraulic cylinders 68, 70 such that the trailer is 3 metres wide in the open mode, as illustrated in Figure 6. At this time the rear lower closing cylinder 210 is raised as shown in Figure 7b. The rear gates and mid gates all open simultaneously with the opening/expansion of the trailer.

[0059] The six wheels 110 support the empty trailer weight. The truck and trailer 10 are substantially aligned with the Superpack 200, and the trailer is reversed to enclose the Superpack 200 within the trailer chassis, approximately centrally to each side 12, 14 of the trailer chassis. If necessary the two Scissor Link Cylinders, 26, 27 can be operated to trim this side to side alignment.

[0060] Next, the hydraulic valve 124, to the lower cavity of the suspension cylinders 118 is supplied with oil under pressure from the reservoir 126. Both valves 122 are activated to release oil in the cylinder cavities 118a, to the oil reservoir 126. The trailer chassis is lowered until the front 202 and rear transverse wheels 152 take the weight of the trailer chassis 10. In this state the six wheels 112 are raised above road level as the cylinder rods 116 are drawn into the cylinders 118.

[0061] Next the hydraulic valve 160 to the turntable link cylinder 34 is operated to lower the front of the trailer chassis, until the chassis angle bars 150 are parallel to the road, to enable pick up of the Superpack 200. This is done by putting the valves to the scissor link cylinders 26, 27 into a float mode, allowing the cylinders to shift as the Superpack is clamped from each side.

[0062] The actual clamping of the Superpack 200 from each side, is effected by shortening both cruciform rams 68, 70 as well as shortening the front and rear opening and closing cylinders 206, 208 and 210. The chassis sides move towards each other, until the cylinders 68 and 70 are fully shortened. As the chassis sides move, the front and rear transverse loading wheels 202 and 152 on each chassis side rolls on the road surface, with the six trailer wheels 110 above the road surface. At this time, there is no hydraulic pressure to the link brakes 80 and the pins 102 slide easily in the slotted chassis plates 46a, b. The rear gates automatically close as the chassis sides move together by means of the connecting rods and bell cranks.

[0063] Once the chassis sides 12, 14 are fully closed with the angle iron bars 150 below the respective outer edges of the Superpack 200, hydraulic pressure in each side of the lower cavity 118b of the suspension cylinders 118 is released to the oil reservoir through hydraulic valve 124. The six wheels 112 return to the road surface.

[0064] Next, both hydraulic valves 122 to the upper cavity 118a of each trailer sides suspension cylinders 118, is opened to supply oil into those three cavities on each side. The trailer chassis 10 lifts until the top faces of the angle iron bars 150 contacts the lower surface of the outer longitudinal edges of the Superpack 200, on each side of the pack. At this stage the front 202 and rear transverse wheels 152 will be above the road due to the shape of the Superpack as shown in Figure 3. As oil is added to the suspension cylinder cavities 118a, the pressure in the cylinders 118 rises as oil fills the suspension cylinder hydraulic accumulator 120 on each side, until the pressure in the suspension cylinders is sufficient to lift the Superpack 200 up from the road surface.

[0065] The lifting of the Superpack 200 continues until the Superpack is at the working height of about 350 mm above the road. The hydraulic pressure in the upper cavity 118a of suspension cylinders, on each side, clamps the brake 80 and the trailer is locked from opening. Finally, the length of each Scissor Link Cylinder, 26, 27, is equalized electronically. The Superpack 200 is now loaded onto the trailer and is ready to be transported.

[0066] Unloading the ingot pack is essentially the reverse of the loading process.

[0067] Although the present invention has been described with reference to a carrying a "Superpack" of aluminium ingots, it will be appreciated that the invention may be used for other applications such a transporting pallets containers and other cargo loads.

[0068] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (20)

1. CLAIMS:

   1. A device for loading, transporting and unloading cargo including a pair of chassis sides, each chassis side including main wheels supporting the device, and a protrusion for engaging with a cargo to be loaded, transported and unloaded, the device further including a link mechanism for expanding and contracting the device by moving the chassis sides towards and away from each other to enable the device to be positioned on either side of a load in an expanded state and subsequently contracted to engage with the load wherein the link mechanism is located above the load in use and is a cruciform linkage comprising two link members of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together, and wherein two transverse wheels are mounted to the rear of each chassis side at the base of the chassis structure for allowing the chassis sides to move laterally when the main wheels are raised above the ground wherein the transverse wheels are arranged such that they are unable to rotate in the same clockwise or anticlockwise direction as each other.
2. 2. A device as claimed in claim 1 wherein the device is a trailer and is mounted on a prime mover or tow motor turntable or the like.
3. 3. A device as claimed in claim 1 or claim 2 wherein the transverse wheels include a ratchet system arranged so that unless the ratchet is disengaged the wheels are prevented from moving in the same direction.
4. 4. A device as claimed in claim 3 wherein that the ratchet system limits the distance the transverse wheels are able to travel along the ground, typically to about 200 to 300mm.
5. 5. A device as claimed in any preceding claim wherein further transverse wheels are also provided at the front of the trailer, as well as at the rear.
6. 6. A device as claimed in claim 5 wherein the further transverse wheels are mounted via a plate to which a stub axle is mounted, the plate having offset bolt holes to allow for height adjustment of the further transverse wheels.
7. 7. A device as claimed in any preceding claim wherein hydraulic cylinders are provided which extend transversely between the chassis sides for assisting in opening and closing the device.
8. 8. A device as claimed in claim 7 wherein the hydraulic cylinders are provided at the front and rear of the device at or towards the bottom of the device and including a further hydraulic cylinder provided at the top of the device, which is phased with the hydraulic cylinders located at or towards the bottom of the device and opens and closes in sync with the those hydraulic cylinders.
9. 9. A device as claimed in claim 8 wherein the further hydraulic cylinder is pivotally mounted at the base of one chassis side so that it can pivot upwardly from a deployed position to an vertical position through about 90° for loading and unloading of the device/trailer.
10. 10. A device as claimed in claim 9 wherein the further hydraulic cylinder includes a piston rod and distal end of the piston rod which locates in the hydraulic cylinder will be enlarged and will engage behind a slot when in the deployed position.
11. 11. A device for loading, transporting and unloading cargo including a pair of chassis sides, each chassis side including main wheels supporting the device, and a protrusion for engaging with a cargo to be loaded, transported and unloaded, the device further including a link mechanism for expanding and contracting the device by moving the chassis sides towards and away from each other to enable the device to be positioned on either side of a load in an expanded state and subsequently contracted to engage with the load wherein the link mechanism is located above the load in use and is a cruciform linkage comprising two link members of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together, and wherein one or more hydraulic cylinders extend between the chassis sides for assisting in opening and closing the device.
12. 12. A device as claimed in any preceding claim wherein gates are provided for closing the rear of the device.
13. 13. A device for loading, transporting and unloading cargo including a pair of chassis sides, each chassis side including main wheels supporting the device, and a protrusion for engaging with a cargo to be loaded, transported and unloaded, the device further including a link mechanism for expanding and contracting the device by moving the chassis sides towards and away from each other to enable the device to be positioned on either side of a load in an expanded state and subsequently contracted to engage with the load wherein the link mechanism is located above the load in use and is a cruciform linkage comprising two link members of substantially equal length which are pivoted to each other at their respective centres where they cross and which link the chassis sides together, and wherein a gate assembly is provided at the rear of the device.
14. 14. A device as claimed in claim 12 or 13 wherein the gates open and close in a vertical plane.
15. 15. A device as claimed in any preceding claim further including means for raising and lowering the main wheels relative to the transverse wheels, to allow the chassis sides to be moved apart and together to load or unload cargo.
16. 16. A device as claimed in any preceding claim wherein a grab rail is defined at the base of each chassis side which defines a horizontal flange or shelf/ledge which juts toward the centre of the device and on which the load is supported in use.
17. 17. A device as claimed in any preceding claim wherein the main wheels are mounted on support legs connected to cylinders allowing the wheels to be raised and/or lowered relative to the base of the device and wherein the lower end of the support leg is mounted to the base of the trailer via a vertically extending pin which is mounted on and extends upwards from the base of the trailer.
18. 18. A device as claimed in claim 17 wherein the lower part of the support leg defines a slot and the pin fits in bushes mounted within the slot in the support leg and wherein the pin allows vertical movement of the leg along the pin.
19. 19. A device as claimed in claim 18 wherein the mounting of the pin in the slot permits rotational movement of the leg about the vertical axis of the pin.
20. 20. A device as claimed in any preceding claim wherein moveable gates are provided part way along the chassis sides which, when deployed, extend inwards.