TECHNICAL FIELD

A roll trailer and methods of loading and unloading the roll trailer are disclosed. The roll trailer has particular, though not exclusive, use in the handling of exceptionally heavy cargo.

BACKGROUND OF THE INVENTION

Roll trailers are known in the art for handling exceptionally large loads (e.g. in the range of 150 to 200 tonnes) such as containers, mining trucks, excavators, etc. Roll trailers are essentially cargo handling tools for carrying and moving exceptionally large loads over short distances in a port, dock or mine site environment. As a result of their functional requirements, roll trailers are generally low-profile and heavily engineered, such that the maximum speed of such trailers is generally limited to between 5 and 8km/h.

A known process for unloading such equipment from e.g. a roll-on roll-off cargo ship includes rolling the roll trailer off the ship (i.e. with the load thereon) and using a crane to lift the load from the roll trailer and position it on the ground or some other surface (e.g.

cribbing).

In order to utilise a crane, it must first be positioned adjacent to the roll trailer, coupled to the load, and then uncoupled once the load has been suitably positioned. Such a process can be time-consuming, especially when many roll trailers require unloading at the same time. It can be the case that a limited number of cranes are available, which restricts the number of roll trailers that can be simultaneously unloaded and reduces the rate at which equipment may be unloaded from e.g. a cargo ship.

Cranes can be expensive to purchase and/or rent, whilst the manual labour to operate the cranes (i.e. including the labour required to couple and uncouple the crane to the load) incurs further expense. This may especially be the case when large cargo is involved (e.g. mining vehicles), which can require larger, more specialised, cranes for handling.

The above references to the background art do not constitute an admission that the art forms part of the common general knowledge of a person of ordinary skill in the art. The above references are also not intended to limit the application of the roll trailer and methods of loading and unloading a roll trailer as disclosed herein. SUMMARY

Disclosed herein is a roll trailer for a load. Also disclosed are methods for loading and unloading the roll trailer. The roll trailer and methods find particular, though not exclusive, application in the loading and unloading of large scale cargo from ships and other forms of transportation.

In a first aspect, a roll trailer for a load is disclosed. The roll trailer comprises a frame structure and at least one support surface for supporting the load thereon. The at least one support surface comprises at least one actuator arranged with respect to the frame structure to move the at least one support surface relative to the frame structure in use and thereby lift the load.

The term "roll trailer", as set forth above, defines a cargo handling tool used for carrying exceptionally heavy loads and moving them over short distances.

The at least one actuator may be, for example, a hydraulic actuator, electric actuator, etc. The actuator may generally be any component forming part of the trailer that is capable of producing a force input to move the at least one support surface. This allows the roll trailer to lift and lower a load independent of any external piece of equipment (e.g. a fork lift). In this way, loading and unloading of the roll trailer may be fast and require minimal labour.

The at least one actuator may include a pressure sensor. This can provide information, such as the weight and weight distribution of a load, to an operator or a control unit. This information can be used to properly control the at least one actuator to ensure balanced, and safe, lifting of the load on the support surface.

The roll trailer can, for example, be operated without requiring the use of a crane. In this regard, crane purchase, rental and maintenance expenses, as well as safety issues, may be eliminated or reduced (i.e. in comparison to use of a known roll trailer). Similarly, less manual labour and time may be required to unload and load the roll trailer.

In one embodiment the at least one support surface may be a platform. The platform may be in the form of a fiat surface for receipt of a load. The roll trailer, for example, may comprise two spaced-apart platforms. In other forms, the roll trailer may comprise more spaced-apart, or adjacent, platforms, or just a single platform. It would be understood by a person skilled in the art that other configurations of platforms may be suitable and that such configurations may be customised to suit a particular cargo.

In one embodiment the platforms may be configured such that they can move independently of one another. The load may be separated into several parts, each being located on a separate platform such that each part of the load may be moved independently of one another for loading and unloading of the roll trailer. Similarly, the lower surface of the load (which is supported by the platforms) may be uneven. In this case, the process of loading the load onto the roll trailer may involve raising the separate platforms independently of one another until they are each in contact with their respective portion of the lower surface of the load. The load may then be raised evenly (i.e. being level) by synchronous actuation of the platforms.

In one embodiment each platform may comprise four actuators for moving the platform relative to the frame structure. The actuators of a respective platform may be configured to move synchronously. This may ensure that the platform remains level when it is being moved relative to the frame structure. The actuators may be hydraulic cylinders, which may be linked mechanically and/or electronically by a control system in order to enable them to move synchronously.

In one embodiment each platform may be rectangular. The platform may be flat, or may be specifically adapted to support a particular load. That is, the platform may have flanges, bolt holes, struts, etc. that are specifically positioned and/or shaped to facilitate securement of a specific load to the platform. The platform may also comprise holes positioned so as to be suitable for tie-down of a load.

When each platform is rectangular, the actuators may be located in the far corner regions of their respective platform. This may spread the load evenly between the actuators and facilitate even (e.g. level) raising and lowering of the load.

In one embodiment, the frame structure may comprise two parallel beams having a plurality of spaced transverse beams extending therebetween. The cross section of each beam may, for example, be "I" shaped, "C" shaped, hollow rectangular, hollow circular, etc. The transverse beams may be arranged such that the space formed between them and the side beams is approximately the shape and dimension of one or more of the platforms. In other words, the arrangement of the beams may provide suitably sized gaps for the one or more platforms.

In one embodiment, the platform(s) may further comprise a guide arranged to delimit movement of the platform along a single axis. This axis may be in the vertical direction, such that further support may be provided to the platform to prevent lateral deflection, deformation and/or buckling of the platform or actuators. This may also increase the precision in the movement of the platform and the load relative to the frame structure.

The guide may be in the form of a skirt extending downwardly and substantially around the perimeter of the platform, such that in use, the skirt member may slidably engage adjacent transverse and side beams of the frame structure to delimit the movement of the platform to a single axis. The skirt may, for example, comprise rails that engage with corresponding grooves on the frame structure. This may further facilitate the delimiting of the movement of the platform to e.g. the vertical axis. The skirt member may be arranged such that when the platform is in its raised position, the skirt covers the gap between the platform and the frame structure. In this way, the skirt may provide protection (i.e. from the external environment) to the actuators and other components that may be located below the platform. This may reduce the amount of maintenance required on the components contained within the skirt and the platform (e.g. hydraulic acutators). The skirt may also increase the safety of the trailer by reducing the number of "pinch points". That is, the skirt may reduce or eliminate the possibility of a limb, finger, etc. of an operator being caught (e.g. during lowering of the platform) between the platform and the frame structure, which could otherwise cause serious injury.

In one embodiment, the roll trailer may comprise a plurality of wheels for the trailer, which may facilitate manoeuvrability of the roll trailer (generally over short distances). The wheels may be located in proximity to an end of the frame structure. For example, the distance between the wheels and the end of the frame structure may be less than two metres. This may prevent tipping of the roll trailer if a load is placed at the end of the trailer. In known roll trailers, the distance between the wheels and the end of the roll trailers is longer than this, such that there is a risk that an operator may position the load on this portion of the roll trailer so as to cause the roll trailer to tip (and thereby potentially causing damage to the load and/or roll trailer). In one embodiment, at least one supporting surface may be located above the wheels. With such an arrangement, the load path/direction may pass directly from the support surface to the ground via the wheels (i.e. rather than having to pass along the frame structure, as is the case when the support surface is not located directly above the wheels or some other support feature in contact with the ground).

In one embodiment the roll trailer comprises one or more fixed platforms arranged such that, when the at least one actuated platform is in its lowered position, the one or more fixed platforms and the at least one actuated platform form a continuous upper surface of the frame structure. Thus, the roll trailer may be used in the same manner as a known roll trailer if the operator chooses to do so. This may be desirable if one or more actuators have malfunctioned, or the moveable platforms are not required for a particular load.

In a second aspect, a method for unloading a load from a roll trailer is disclosed. The load may be, for example, general cargo, heavy machinery, vehicles etc. The roll trailer is as set forth above with respect to the first aspect. The method comprises the step of actuating the at least one actuator to raise the at least one support surface relative to the frame structure, thereby raising the load. The method further comprises the step of supporting the load on either side of the roll trailer and actuating the at least one actuator to lower the at least one support surface relative to the frame structure whereby the load remains supported independently of the roll trailer.

In one embodiment the load may be supported on either side of the roll trailer by cribbing. The cribbing may be in the form of plates, mats, blocks etc. It would be understood by a person skilled in the art that cribbing may be in other forms suitable for supporting the load above the ground.

In one embodiment, when the roll trailer comprises two spaced-apart platforms as set forth above, the platforms may be moved independently of one another when raising and/or lowering the load. When the load is made up of several independent parts, this may allow independent raising and lowering of these parts. Similarly, this may allow re-orientation of the load, for example, if one platform is raised to a higher or lower level with respect to the other platform. In one embodiment the actuators for each platform may be moved synchronously when raising and/or lowering the load. This may help to ensure that the load, or portion of the load, supported on each platform is raised and/or lowered evenly.

In one embodiment the method may further comprise the step of relocating the roll trailer away from the load once the load is supported independently of the trailer. This provides a space underneath the load that may (in the case that the load is machinery or a vehicle) allow for further or final assembly of the load (e.g. coupling wheels to a vehicle).

In one embodiment the relocation of the roll trailer may be facilitated by a vehicle that is coupled to the roll trailer. For example, the roll trailer may be configured for attachment to a vehicle, which could be utilised to tow the roll trailer in order to relocate it.

In a third aspect, a method for loading a load on to a roll trailer is disclosed. The roll trailer is as set forth above with respect to the first aspect. The method comprises the steps of supporting the load independently of the roll trailer and positioning the roll trailer beneath the independently supported load. The method further comprises the step of actuating the at least one actuator to raise the at least one support surface of the roll trailer relative to the frame structure of the roll trailer, until the load is fully supported by the at least one support surface.

In one embodiment, the load may be independently supported by cribbing. The cribbing may be in the form of plates, mats, blocks etc. It would be understood by a person skilled in the art that cribbing may be in other forms suitable for supporting the load above the ground.

In one embodiment, the method may further comprise the step of removing the cribbing from beneath the load (i.e. after the at least one support surface is supporting the load). The at least one support surface may then be lowered. The trailer may then be moved away from the cribbing and may, for example, be loaded on to a truck, ship, etc.

In one embodiment the platforms may be moved independently of one another when raising or lowering the load.

In one embodiment the step of raising the at least one support surface may comprise raising a first platform until it comes into contact with a lower surface of the load, and raising a second platform until it comes into contact with a lower surface of the load. The step may further comprise raising both platforms synchronously, in order to raise the load relative to the frame structure of the roll trailer. In some cases the lower surface of the load may be uneven, and thus a portion of the surface may be positioned higher above one platform compared to one or more other platforms. Thus the initial raising of the platforms, to be in contact with their respective portions of the lower surface of the load, may help to ensure that the load is thereafter raised evenly (i.e. without tipping).

In one embodiment the actuators for each platform may be configured to move synchronously. As set forth above, this may help to ensure that the load, or portion of the load, supported on each platform is raised and/or lowered evenly (so as to avoid tilting and/or rolling of the load).

In one embodiment, where the roll trailer comprises wheels, positioning of the roll trailer beneath the independently supported load may be facilitated by the wheels. The positioning of the roll trailer may be further facilitated by a vehicle that is coupled to the roll trailer (e.g. for towing).

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the roll trailer and methods as set forth in the Summary, specific embodiments will now be described, by way of example only, with reference to the accompanying drawings in which:

Figures 1A, B and C show an embodiment of the roll trailer.

Figures 2A and B are a perspective and section view of a variation of the embodiment shown in Figures 1A, B and C.

Figures 3A, B, C and D are side and perspective views of a further embodiment of the roll trailer.

Figures 4A, B and C are side views of an embodiment of the roll trailer in various stages of unloading a load.

Figures 5A, B, C and D are side views of an embodiment of the roll trailer in various stages of loading a load. DETAILED DESCRIPTION

In the following detailed description, reference is made to accompanying drawings which form a part of the detailed description. The illustrative embodiments described in the detailed description, depicted in the drawings and defined in the claims, are not intended to be limiting. Other embodiments may be utilised and other changes may be made without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings can be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.

Referring to Figures 1A, B and C, a roll trailer 110 for handling a load is shown. This roll trailer 110 is sized so as to be capable of being positioned beneath a load (such as a container or mining vehicle) and between cribbing, allowing it to be loaded and unloaded with minimal difficulty. The trailer 110 is capable of handling loads in the range of 150 to 200 tonnes (although other embodiments may be suitable for handling larger loads). In the illustrated form, the trailer comprises two support surfaces in the form of spaced apart platforms 112a, 112b. In other forms the roll trailer may comprise more or less platforms; for example 1, 3 or 4 platforms. The platforms 112a, 112b are flat and rectangular in shape, although in other forms they may have a configuration that is adapted to suit a specific type of load (e.g. formed so as to complement the underside of a vehicle). It would be understood by a person skilled in the art that the platforms 112a, 112b could take other forms suitable for supporting a load. In the illustrated form, the platforms 112a, 112b are of a different size (i.e. when viewed from above) and hence may each be suitable for supporting loads having different shapes or sizes.

A frame structure 114 supports the platforms 112a, 112b. The frame structure 114 comprises two longitudinal beams 116 that extend the length of, and either side of, the trailer 110. The longitudinal beams 116 are interconnected by a plurality of transverse beams 118 that span the gap formed between the longitudinal beams 116. All of the beams (i.e. transverse 118 and longitudinal 116) have C-shaped cross sections, but in other forms one or more of the beams may have I-shaped cross sections (I-beams), hollow (e.g. circular, rectangular) cross sections etc.

Each platform 112a, 112b is supported by four actuators in the form of hydraulic cylinders 120, which are located at the corners of their respective platform 112a, 112b. Such an arrangement means that, in general, the load is spread evenly between the hydraulic cylinders 120. The hydraulic cylinders 120 are themselves supported by a transverse beam 118 of the frame structure 114. Figure 1A shows the platforms 112a, 112b in their raised position, with the hydraulic cylinders 120 extending upwardly.

The hydraulic cylinders 120 are configured such that they extend synchronously. In this way, the platforms 112a, 112b remain level as they are raised and lowered. This can reduce or eliminate tilting and any resultant slipping of a load located thereon. Although not apparent from the Figures, the hydraulic cylinders 120 are configured such that the platforms 112a, 112b may be raised and lowered independently of one another. Thus, the platforms may be individually raised and lowered to meet the various requirements of loads having a range of shapes and weight distributions.

The roll trailer 110 of the illustrated embodiment further comprises two sets of four wheels 122, all of which are located at a rear end of the trailer 110. The location of the wheels 122 at the end of the trailer 110 is such that the length of frame structure 114 between the wheels 122 and the end of the trailer 110 is minimal. This is in contrast to conventional roll trailer designs, where this distance (between the end of the trailer 110 and the wheels 122) is much larger. The larger cantilever of the rear end of the trailer from the wheels of convention trailers (i.e. when compared with the roll trailer as disclosed herein), can introduce the risk of the roll trailer tipping when a load is placed at its rear end. Tipping could cause damage to the load and/or the trailer, or could result in serious injury of an operator. Although dependent on a range of factors, a cantilever of less than 2m (as shown in the illustrated embodiment) may help to significantly reduce this risk.

The rear platform 112b (i.e. that being closest to the rear end of the roll trailer 110) is located directly above the wheels 122. With such an arrangement, the load path passes directly from the support surface to the ground via the wheels 122 (i.e. rather than having to pass laterally along the frame structure 114, as may be the case when the platform 112 is not located directly above the wheels 122 or some other feature in contact with the ground).

At the opposite end (to the rear platform 112b) of the roll trailer 110 are two coupling members in the form of hooks 134. The hooks 134 are formed so as to be suitable for coupling to a vehicle, which allows the trailer 1 10 to be manoeuvred by the vehicle for the purposes of handling, loading or unloading a load. Figure IB, in particular, shows the platforms 112a, 112b in their lowered (i.e. flush) position. The roll trailer 110 comprises fixed platforms 124 arranged on top of the frame structure 114, which form a continuous upper surface with the platforms 112a, 112b when the platforms 112a, 112b are in the lowered position. In this way, the roll trailer may be used in the same manner as a conventional roll trailer.

Figures 2 A and B show a further embodiment of a roll trailer 210. In this embodiment each platform 212a, 212b further comprises a guide member in the form of a skirt 226a, 226b. Each skirt 226a or b extends downwardly from and around the perimeter of its respective platform 212a, 212b. In the illustrated form each skirt 226a, 226b acts as a guide for its platform 212a, 212b whereby it helps to restrict movement of the platform 212a, 212b to the vertical axis. The restriction of lateral movement may support extension of the rams of the hydraulic cylinders 220, thereby helping to prevent them from buckling (e.g. when a supported load shifts laterally, or has a centre of gravity that is offset from the centre of the platform).

The skirts 226a, 226b cover the gap between their respective platforms 212a, 212b and the frame structure 214. In this way, the skirts 226a, 226b may also provide protection (i.e. from the external environment) to the actuators 220 and other components that may be located below the platforms 212a, 212b. As set forth above, this reduces the maintenance requirements of the protected components. The skirts 226a, 226b may also reduce or eliminate the risk of the limb, fingers, etc. of an operator being caught between the a platform 212a, 212b and the frame structure as the platform 212a, 212b is limited. That is, the skirts eliminate "pinch points" from this portion of the trailer 210.

Figure 2B, in particular, shows a sectional view through a portion of the roll trailer 210 comprising one of the platforms 212a, 212b. As illustrated, each actuator (each in the form of a hydraulic cylinder 220) is connected at one end to the underside of the platform 212a, 212b and at the other end is supported by a transverse beam in the form of a U-shaped channel 228. The U-shaped channels 228 are arranged such that they lie below the longitudinal beams 216. This provides a larger space between the channels 228 and platforms 212a, 212b, such that larger hydraulic cylinders (i.e. having a larger stroke) may be fitted in this space. This arrangement also allows the height of the roll trailer 210 to be minimised (whilst retaining the stroke length). This facilitates loading and unloading of loads onto the platforms 212a, 212b, as it allows the trailer 210 to be easily positioned below a load supported on e.g. cribbing (for loading) and to easily be removed from beneath a load (when unloading).

The further embodiment shown in Figures 3A, B, C and D generally comprises the same features as the embodiments described above. The roll trailer 310 comprises raiseable and lowerable platforms 312a, 312b, a frame structure formed of longitudinal side beams 318 and transverse beams 318, hydraulic cylinders 320, and wheels 322. Each platform 312a, 312b comprises a downwardly extending skirt 326a, 326b that protects the hydraulic cylinders 320 and generally eliminates pinch points. The skirt 326b of the rearmost platform 312b comprises cut-out portions which accommodate the wheels 322 of the trailer 310 when the platform 312b is in its lowered position.

Figures 4 A, B and C depict a method of unloading a load 430 roll trailer 410 having moveable support surfaces (in the form of platforms 412) as set forth above. Figure 4A shows a roll trailer 410 positioned such that it is ready to be unloaded. The trailer 410 comprises platforms 412a, 412b that are raised so as to support a load 430 thereabove.

In Figure 4B, cribbing 432a, 432b has been introduced beneath the load (e.g. by hand or using equipment) to support the load 430. The cribbing 432a, 432b may be in the form of plates, mats, blocks etc. It would be understood by a person skilled in the art that cribbing 432a, 432b may take other forms suitable for supporting a load above the ground. The cribbing 432a, 432b is positioned either side of the roll trailer 410 so as not to interfere with removal of the roll trailer 410 after the unloading process. Subsequently, the platforms 412a. 412b are lowered by actuation of their respective actuators (in the form of hydraulic cylinders 420). In this way, the load 430 becomes fully supported above the ground solely by the cribbing 432a, 432b.

The roll trailer 410 is then moved (e.g. towed) away from the load, as shown in Figure 3C, such that a space is left under the load 430 (i.e. between the ground and the load 430). This space may (in the case that the load is machinery or a vehicle) allow for further or final assembly of the load (e.g. by coupling wheels to a vehicle). The roll trailer 410 may be moved by a vehicle that can be coupled to the roll trailer via a standard roll trailer goose neck 434. The moving of the roll trailer 420 away from the load is facilitated by the low profile of the roll trailer 410. A method of loading a load 530 onto a roll trailer 510 is shown in Figures 5A, B, C and D. In Figure 5A, a load 530 is shown supported above the ground by cribbing 532. This may be the regular storage position of the load 530, or the load 530 may be arranged in such a manner so as to facilitate its loading on to a roll trailer 510.

In Figure 5B the roll trailer 510 is positioned (i.e. manoeuvred by a vehicle) beneath the load 530. The external dimensions of the roll trailer 510 are selected so as to allow the roll trailer 510 to fit below the load and between the cribbing 532. Subsequent to positioning the trailer 510, the platforms 512a, 512b are raised. The lower surface of the load 530 is not even. In other words, the portions of the lower surface lying above the platforms 512a, 512b do not lie on the same plane. Thus, if the platforms were raised synchronously the rear platform 532b would engage the underside of the load first and begin to tilt the load (potentially causing damage to the load and/or trailer, or causing injury to an operator). To engage the load 530, the platforms 512a, 512b are raised independently. Each platform 512a, 512b is individually raised until it comes into contact with a respective portion of the lower surface of the load 530. Subsequent to this, the platforms 512a, 512b may be raised synchronously in order to raise the load 530 above the cribbing (such that the load remains level and does not tilt). By doing so, the load 530 becomes fully supported by the roll trailer 510.

In Figure 5C, the cribbing 532a, 532 b has been removed from beneath the load. In Figure 5D the load 530 has been lowered by synchronous lowering of the platforms (i.e. via actuation of the hydraulic cylinders 520. In this position the load 530 may be more secure (i.e. in comparison to it being maintained raised above the roll trailer 510).

The raising and lowering of loads, and synchronous and asynchronous control of the hydraulic cylinders, may be programmed into suitable controllers, such that loading and unloading sequences can at least be partially automated, and errors can be minimised. In this respect, suitable fail-safe control procedures can be pre-programmed.

In the claims which follow and in the preceding summary except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", that is, the features as above may be associated with further features in various embodiments. Variations and modifications may be made to the parts previously described without departing from the spirit or ambit of the disclosure.

For example, whilst two platforms have been shown, a roll trailer with a single platform for smaller loads can be provided. Also, for loads with more complex configurations, roll trailers with multiple platforms, such as three or more linearly and/or transversely (side-by-side) platforms can be provided.

In the embodiments described above, the platforms are generally rectangular and flat. In other words, they are not specifically formed for any particular type of load. In other embodiments, the platform may be specifically adapted to support a particular load. That is, the platform may have flanges, bolt holes, struts, etc. that are positioned and/or shaped to facilitate securement of a specific load (i.e. having a particular shape or load distribution) to the platform. The platform may also comprise holes positioned so as to allow tie-down of a load.

The hydraulic cylinders may include pressure sensors that can provide information (e.g. related to weight or weight distribution of a load) to an operator or control system. The information may be used to ensure safe or optimal handling of a load.

Also, for non-rectangular platforms, different and suitable arrangements of the actuators can be provided (e.g. up to six to eight actuators for a circular platform, etc).