Load carrying apparatus

TECHNICAL FIELD

[0001] The present invention relates to a load carrying apparatus. In more specific embodiments, the present invention relates to a load carrying apparatus that is used to load cargo, such as produce or equipment, into containers. The load carrying apparatus is fitted with sensors to enable the weight of the produce or equipment to be determined.

BACKGROUND ART

[0002] Cargo is frequently transported using ISO standard shipping containers. ISO standard shipping containers may be simplistically described as large metal boxes into which cargo is placed. The shipping containers can then be moved and placed by transport handling equipment onto various vehicles, such as trucks, trains and ships. As the ISO standard shipping containers come in a relatively small number of standard sizes, standardised container handling equipment and standardised container loading patterns can be used.

[0003] Containers are physically large, heavy objects. For example, some shipping containers have a length of 40 feet (12.192 m), a height of 8'6" (2.591 m) and a width of 8 feet (2.438 m). Applicable ISO standards allow such shipping containers to have a total gross mass when loaded of up to 30,480 kg. Operator safety is very important when handling such large, heavy objects.

[0004] The International Maritime Organisation has recently passed regulations requiring that every container loaded onto a ship must have its weight verified by a local authority. In the absence of such verification of weight of the container, that container will not be allowed to be loaded onto a ship. Ideally, the weight of a container should be determined before it reaches the port or docks as if a loaded container is weighed at the port or docks and it is overweight, that container will be rejected and will need to be repacked and reweighed. Thus, it is desirable to have the weight of the container determined at loading or shortly after loading.

[0005] There are two possible ways of determining the total weight of the container. One is to load the container and move it onto a weighbridge to weigh the total weight of the container. The other is to weigh the total weight of cargo, pallets and strapping loaded into the container and add that to the tare weight of the container to determine a total weight of the loaded container.

[0006] Loading of cargo into containers has proved to be problematic in the past. In order to load a container, the end doors are fully opened and the cargo loaded into the container through the end doors. This requires a load carrying apparatus to lift the load and move the load through the doors and into the container. Forklifts are frequently used to load containers. However, forklifts have relatively short forks and thus can only carry relatively short cargo. Therefore, the forklift must make a number of separate trips into the container to fully load the container. This increases safety risks when loading the container.

[0007] One system that is used for loading long loads into containers is provided by Joloda International. In this system, portable rails are laid in the container and on a loading plinth that is immediately adjacent the opening of the container. Skates with a 28 tonne capacity are fitted to the rails. A load is then positioned above the skates. When the load of cargo has been finalised on the skates, the skates are lifted so that they lift and support the container. The skates are moved along the rails to move the load into the container. The skates are then lowered so that the weight of the cargo is taken by the floor of the container. The skates may then be retracted from the container and the rails in the container may be removed. Although this system does allow for one-shot loading of containers, it requires assembly and disassembly of the rails in the container. Further, the skates are manually moved by an operator. The loading plinth is suitably set up so that it angles downwardly at 1° to assist in moving the load into the container. As the loads may weigh up to 28 tons, it may not be desirable to have such heavy loads being manually moved by operators.

[0008] Another solution to loading long or heavy loads into a container is described in international patent publication numbers WO 03/068658 and WO 03/068659, both in the name of Tynecat Technologies Pty Ltd. The entire contents of these international patent publications are specifically incorporated herein by cross-reference.

[0009] These international patent publications describe a load carrying apparatus in the form of a transport trolley having 2 spaced trolley forks. Each trolley fork is supported by rollers. One or more of the rollers may be extendable and retractable so that the forks can be raised and lowered. When raised, the forks bear the weight of the load. When lowered, the forks are below pallets that support the load and thus the pallets bear the weight of the load. The transport trolley of these international patent applications is also fitted with a steering system that includes sensors incorporated in the forks. If the trolley diverges from a pre-set spacing, an electronic control system steers the trolley so as to maintain the pre-set spacing between the forks and the container wall. The transport trolley may also include a device for determining the position of the trolley. For example, the transport trolley may be provided with a measuring wheel that can measure how far the trolley has moved from a starting position.

[0010] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF INVENTION

[0011] The present invention is directed to a load carrying apparatus that can be used to load cargo into containers and also allows the weight of the loaded container to be determined. In some embodiments, the invention also allows the load distribution or centre of gravity (COG) to be determined.

[0012] In a first aspect, the present invention provides a load carrying apparatus comprising at least two spaced arms, each of the arms having an upper surface that can be raised to support a load and lowered to be spaced from the load, each arm having at least one roller that contacts a surface over which the load carrying apparatus is travelling, each arm including a weighing sensor for determining a weight of the load on the arm.

[0013] In a second aspect, the present invention provides a load carrying apparatus comprising at least one arm, each of the at least one arm having an upper surface that can be raised to support a load and lowered to be spaced from the load, each of the at least one arm having at least one roller that contacts a surface over which the load carrying apparatus is travelling, and a weighing arrangement for weighing a weight of the load on the at least one arm once the upper surface of the at least one arm has been raised to support the load. In an embodiment of this aspect of the invention, the at least one arm comprises two or more spaced arms.

[0014] In a third aspect, the present invention provides a load carrying apparatus comprising a load carrying platform having an upper surface that can be raised to support a load and lowered, the platform having at least one roller that contacts a surface over which the load carrying apparatus is travelling, and a weighing arrangement for weighing a weight of the loads on the platform once the upper surface of the platform has been raised to support the load, the weighing arrangement including a plurality of weight sensors for providing information indicative of a weight determined by each of the plurality of weight sensors, the plurality of weight sensors including at least a first weight sensor and a second weight sensor spaced from the first weight sensor. Preferably, the plurality of weight sensors further includes a third weight sensor spaced from the first weight sensor and spaced from the second weight sensor. In some embodiments, a fourth weight sensor that may be provided, the fourth weight sensor being spaced from the other weight sensors.

[0015] In the load carrying apparatus of the present invention, the one or more rollers are suitably located underneath the arms or the support platform.

[0016] In one embodiment, a pin supports one or more rollers and the weighing sensor is mounted to or in the pin. In one embodiment, each arm is provided with a plurality of pins and each pin is provided with a weighing sensor.

[0017] In one embodiment, a plurality of weighing sensors are provided on each arm.

[0018] In one embodiment, the arm comprises a tine or a fork. In another embodiment, the arm comprises an arm of a sled arrangement.

[0019] In one embodiment, each weighing sensor sends a signal indicative of a weight determined by the sensor to a weight calculator, the weight calculator determining a total weight of the load from the signals received from each weighing sensor.

[0020] In one embodiment, the weight calculator determines a total weight of the container by adding the total weight of the load to the tare weight of the container

[0021] The weight calculator may include functionality to cause a written record of the total weight of the container to be printed. The total weight of the container may be printed on a sticker to adhere to the container. The total weight of the container may be printed and the written record subsequently attached to the container or placed in a holder mounted to the container. In this manner, the written record may be inspected by personnel involved with moving the container.

[0022] In some embodiments, the written record may also include a date that the weight was calculated. In some embodiments, the written record may also include a certification certifying that the weight has been properly determined.

[0023] In some embodiments, the weight calculator may comprise a programmable logic control (PLC) or a computer. The weight calculator may include appropriate algorithms to determine the total weight of the load. The weight calculator may also enable an operator to input a tare weight of the container. Alternatively, the weight calculator may enable an operator to enter an identifier for the container (such as a serial number) in the weight calculator can obtain the tare weight of that container from details entered against the identifier for the container. The weight calculator may record details of the container and the weight of the load that has been loaded into the container in an electronic file. The weight calculator may be operative to transmit details of the total weight of the container or the weight of the load in the container to a record-keeping facility or to an outside agency. The details may be transmitted via a wired communications network, or via a wireless communications network.

[0024] In one embodiment, it may be possible to also determine a location of a centre of gravity of the load. In this embodiment, the apparatus comprises at least two weighing sensors for a single axis of COG or three weighing sensors for 2 axis COG spaced from each other, each weighing sensor determining a weight applied by the load to that weighing sensor, the apparatus further including a weight calculator that receives signals indicative of the weight applied by the load to each weighing sensor, the weight calculator calculating a total weight of the load and a location of the centre of gravity of the load.

[0025] In one embodiment, the apparatus comprises at least four weighing sensors spaced from each other, each weighing sensor determining a weight applied by the load to that weighing sensor, the apparatus further including a weight calculator that receives signals indicative of the weight applied by the load to each weighing sensor, the weight calculator calculating a total weight of the load and a location of the centre of gravity of the load.

[0026] The above embodiments for calculating a centre of gravity of the load a useful where the load is put into the container in a single shot such that the entire load in a container is carried in a single trip into the container. However, in some loading operations, a number of trips are required in order to place the load into the container. In this embodiment, it may still be possible to determine the centre of gravity of the total load by determining the weight and centre of gravity of each shot loaded into the container, determining the location of each shot in the container and determining the centre of gravity of the total load from that information.

[0027] In this embodiment, the apparatus may also be provided with position determining means. The position determining means may comprise a distance measuring wheel that measures the distance that the apparatus moves from reference position. In other embodiments the position determining means may comprise a radar arrangement, a sonar arrangement or a laser arrangement that is used to determine a distance of the trolley from an end of the container when a shot load on the trolley is unloaded into the container. In another embodiment, the position determining means may comprise a GPS based system. In other embodiments, the position determining system may comprise a radio transponder that emits a signal that enables the location of the transponder to be determined, an infrared based system that uses infrared emitters, for example, to reflect off the walls of the container so that the location of the infrared emitters on the load carrying apparatus can be determined and hence the position of the load carrying apparatus can also be determined, magnetic based systems and LVDT (Linear Variable Differential Transformer) based systems, which are a common type of electromechanical transducer that can convert the rectilinear motion of an object to which it is coupled

mechanically into a corresponding electrical signal. Other position sensors that are known to the person skilled in the art may also be used in the present invention.

[0028] The weighing sensors may comprise a shear pin load cell. The shear pin load cell is suitably mounted to a pin that connects a roller or roller assembly to the arm. In one

embodiment, a hole is drilled into an end of the connecting shear pin and the load cell is mounted into the hole using a suitable adhesive. The shear pin load cell will typically have electrical connectors enabling the respective ends of the shear pin load cell to be connected to wires. The wires enable a voltage to be passed across the shear pin load cell. Deformation of the shear pin and the load cell caused by loading the arm with cargo causes a change in resistance of the load cell consequently causing a change in voltage or current signal and that change in signal correlates to the weight applied to the pin. The communication wires will typically be connected to a controller or a computer, with the controller or computer being able to measure the change in voltage and therefore determine the weight applied to the pin. It may also be possible that the load cell can communicate wirelessly with the controller or computer. Shear pin load cells are well known to persons skilled in the art.

[0029] Other weighing sensors may also be used. Examples include beam load cells, ring torsion load cells, single point load cells, canister load cells, tension load cells, plate load cells and force load cells. The skilled person will appreciate that there are many commercially available weighing sensors that could be used in the present invention.

[0030] Other weighing techniques may also be used. Examples include hydraulic pressure on a known area supporting the load, electrical actuators. Other methods of measuring deflection other than resistance load cells may be used, such as physical deflection monitors, video extensometers, and digital image correlation. Any apparatus to measure deflection, strain or stress including speckle shearing interferometry, electrical strain gauges, mechanical

deflectometers, visual or video deflectometers, wave and frequency deflectometers may be used to achieve the measurement of the load. [0031] All of the above weighing sensors or weighing techniques may form part of the weighing arrangement of the second aspect of the present invention.

[0032] The load carrying apparatus may comprise a transport trolley as described in international patent application numbers WO 03/068658 and WO 03/068659. In this

embodiment, the transport trolley may have at least two interconnected, parallel, spaced forks each having at least two roller housings; a roller assembly pivotally connected to each said roller housing; and rollers mounted within each said roller assembly, and when the trolley moves over uneven ground, the or each roller assembly pivots the rollers to maintain contact with the ground.

[0033] The forks may be of any suitable shape, size and construction. Preferably, the forks are shaped for insertion between the blocks of a single-decked pallet. The trolley may have any suitable number of forks. Preferably, the trolley has two forks.

[0034] Each fork may have any suitable number of roller housings. The number of roller housings may depend on the length of the forks and the nature of the palletised cargo that the trolley is to transport. Typically, a trolley for transporting loads about 12 m in length will have two roller housings per fork, whereas trolleys for transporting 18 m loads will have three roller housings per fork.

[0035] Preferably, each fork has a first roller housing and a second roller housing. The first and second roller housings may be located immediately adjacent one another or they may be spaced from one another. Preferably, the first roller housing is located at a forward region of each said fork and the second roller housing is located at a central or rearward region of each said fork. If the second roller housing is located at the central region, then the trolley may further have one or more ground-contacting wheels mounted to a rear end of the trolley.

[0036] Each fork may have a first spacer arm for spacing the first load support from the second load support. The first spacer arm may be of any suitable size, length and construction, it may be adjustable in length, and it may be detachably attachable to the first and/or second load supports. The first spacer arm may have a top wall, a bottom wall and sidewalls. The first spacer arm may, for instance, consist of box steel.

[0037] If necessary, a stiffening member may extend through each first spacer arm from the first load support to the second load support.

[0038] Each fork may include a second spacer arm extending from the second load support to the rear end of the trolley. This arm may be of any suitable size, length and construction, it may be adjustable in length, and it may be detachably attachable to the second load support.

Preferably, the second spacer arm is of similar construction to the first spacer arm and has a top wall, a bottom wall and sidewalls. The second spacer arm may, for instance, consist of box steel. If necessary, a stiffening member may extend through each such arm.

[0039] Each fork may have additional spacer arms for spacing additional load supports.

[0040] The first and second roller housings may be of any suitable shape, size and construction. Preferably, the first and second roller housings are of similar construction, and the first and second roller housings of one fork are substantially mirror images of the first and second roller housings of the other fork. In other embodiments, the roller housings of one fork are linear repeats of those on the other fork. In a further embodiment, the roller housings may be of a unique design.

[0041] Preferably, each said roller housing includes a top wall, a bottom wall having an opening through which a said roller housing extends, and sidewalls and end walls surrounding the roller assembly.

[0042] Each roller housing may further have strengthening walls intermediate the top and bottom walls. The top walls of the first and second roller housings may be situated above the first and second spacer arms so that the arms are not under load.

[0043] Preferably, each said roller housing further includes a peripheral skirt extending between the top and bottom walls. The skirt may partly or fully surround the sidewalls, end walls and intermediate walls. One or more sections of the skirt may be detachable from the top and bottom walls so that an interior of the load support may be accessed.

[0044] The trolley may have a control tower having one or more compartments for containing, for example, controls, displays, a motor or engine, hydraulic components, electronic components, a battery.

[0045] The forks may be interconnected in any suitable way. The forks are preferably interconnected at the rear end of the trolley by a connecting frame. The connecting frame may be of any suitable construction. The connecting frame may have frame members extending between the forks and extending parallel to the forks. The frame members may, for example, consist of metal or composite beams screwed and/or welded to one another and to the forks. The connecting frame may further include plates for connecting the control tower to the frame members. [0046] The roller assemblies may be of any suitable shape, size and construction. If necessary, additional roller assemblies may be mounted to parts of the forks other than to the roller housings.

[0047] Preferably, each roller assembly has a pitched roof with sidewalls and end walls extending from the roof. The pitched roof provides the roller assembly with additional space for rocking.

[0048] The roller assemblies may be pivotally connected to the roller housings in any suitable way. Preferably, each said roller assembly includes a pin extending through said sidewalls of said roller assembly and said sidewalls of the respective roller housing, and the roof may pivot relative to the pin. In this way, the roller assembly may pivot in a rocking motion beneath the top wall of the roller housing.

[0049] Any suitable number of rollers may be mounted within each roller assembly. Any suitable type of roller may be used. (The term "roller" as used herein is to be understood as being synonymous with the term "wheel"). The rollers may be mounted in any suitable way.

Preferably, each roller assembly includes forked roller frames and pins for connecting the rollers to the forked roller frames and for connecting the forked roller frames to the sidewalls of the roller assembly.

[0050] In one embodiment, forward-, mid- and rearward-pairs of rollers are mounted within each roller assembly. In another embodiment, the forward- and rearward-pairs of rollers of each roller assembly are substituted for single, more elongate rollers. Such rollers may reduce the amount of damage to the ground over which the trolley travels. In yet another embodiment, each roller assembly has one or more additional rollers (idlers) for load sharing purposes. In one embodiment, each roller assembly has a single forward roller, a single rearward roller, and a mid-pair of rollers. In another embodiment the each roller assembly has one single rear roller and two forward rollers. In another embodiment each roller assembly has one single forward roller and pair of rear rollers.

[0051] The height of the upper surface of the arms may be adjustable and this may be achieved in any suitable way. Preferably, the upper surfaces of the arms are height adjustable by extending and retracting the rollers relative to the roller housings. To this end, each roller assembly preferably includes forked roller frames that are pivotally connected to the sidewalls of the roller housing.

[0052] The rollers may be extended and retracted by any suitable mechanism. Preferably, each said roller assembly includes an extendable and retractable cylinder, such as a hydraulic lifting cylinder, for moving the rollers between extended and retracted positions. A housing of the lifting cylinder may be pivotally connected to the roof and a piston of the cylinder may be pivotally connected to a said pin connecting the mid-pair of rollers to their respective forked roller frames.

[0053] Preferably, the rollers of a roller assembly are pivoted in unison. To this end, each said roller housing may have tie members interconnecting the rollers such that when the mid-pair of rollers pivots, all of the rollers of the roller assembly pivot. Each roller housing may further include a pivotable tie support member extending between each said tie member and a sidewall or roof of the roller assembly. The tie support members may help prevent the tie members from buckling when under load. Preferably, for load sharing purposes, each roller assembly further includes three idlers connected to the tie members.

[0054] The trolley may have pressure sensors for confirming that a load has been fully lifted or fully lowered. Such sensors are well known in the art. Such sensors may include pressure limits on hydraulic lift cylinders, contactors, limit switches or indeed any other means of determining that each lifting assembly on the forks has completed the required lifting or lowering function. Weighing of the load and determination of the centre of gravity of the load suitably occurs after the load has been fully lifted and is suspended on the arms or forks of the load carrying apparatus. In some embodiments, the sensors for confirming that the load has been fully lifted may send a signal to the controller confirming that the load has been fully lifted. Once the controller receives that signal, the controller receives signals from the weighing sensors to weigh the load. The weight calculator and centre of gravity calculator can then determine the weight of the load on the apparatus and centre of gravity of that load. In some embodiments, the controller may actuate the weight sensors only after the controller has received a signal confirming that the load has been fully lifted

[0055] In order to load the trolley with cargo, the forks may be positioned between blocks of a pallet carrying cargo with the rollers in the retracted position, and in order to lift the palletised cargo, the rollers may be moved to the extended position, at which time the upper surface of the arms/forks bear against deckboards of the pallet.

[0056] The trolley may have a motor such that the trolley is self-propelling. The motor may be located at the rear end of the trolley. The motor may power the hydraulic lifting cylinders. Alternatively, the trolley may be propelled manually or by any vehicle having sufficient tractive effort and braking capacity. The trolley may be propelled by, for example, a forklift truck or by a hydraulic arm of a crane. The rear end of the trolley may be coupled to the forklift truck or to the hydraulic arm of a crane in any suitable way. For instance, the second spacer arms may have pockets for tines of a forklift truck at the rear end of the trolley, and/or the trolley may be coupled to a forklift truck with a chain. The forklift truck or crane may power the hydraulic and electrical systems of the trolley.

[0057] The trolley may have a steering system that enables the trolley to be steered manually and/or automatically. The steering system may be any suitable type of system known to persons skilled in the art. The steering system may include distance monitors connected to at least one of the forks for monitoring the distance between the at least one fork (hereafter referred to as the "monitoring fork") and at least one sidewall of a container; a drive system for steering the rollers relative to the forks, and an electronic control system, operatively connected to the distance monitors and the drive system, for activating the drive system such that the monitoring fork may be maintained at a pre-set distance from the container sidewall.

[0058] Any suitable type of distance monitor may be used. Each distance monitor may be, for example, an ultrasonic sensor. Each distance monitor may be, for example, a photoelectric sensor, such as a laser sensor or an infrared sensor, such as the KM1 series of amplifier built-in analogue sensors sold by Pepperl+Fuchs Australia Pty Ltd, or the WTA 24 photoelectric proximity switches with analogue output series (model number WTA 24-P5201 S01) which is sold by Sick Pty Ltd. Details of the aforementioned distance monitors and other suitable distance monitors may be found at the web sites http://www.pepperl-fuchs.com/ and

http ://w w w . sick, de/de/en .html .

[0059] The steering system may have two distance monitors connected to the monitoring fork for monitoring the distance between the monitoring fork and a single sidewall of the container. Preferably, a first distance monitor is mounted to a forward region of the monitoring fork and a second distance monitor is mounted to a central or rearward region of the monitoring fork. More preferably, the distance monitors are connected to load supports of the monitoring fork.

[0060] The distance monitors may be connected to the fork in any suitable way. If necessary, the trolley may have further distance monitors connected to the monitoring fork or to the other fork such that the distance between both forks and both container sidewalls is monitored.

[0061] Any suitable drive system for steering the rollers relative to the forks may be used. Preferably, the drive system includes hydraulic steering cylinders that steer the rollers. A piston of each hydraulic steering cylinder may be movable between three positions, wherein in a mid- position the trolley is steered straight, in an extended position the trolley is steered left, and in a retracted position the trolley is steered right.

[0062] The trolley may further have roller assemblies for containing the rollers. The roller assemblies may be mounted to the forks in any suitable way. Preferably, each said roller assembly has a mounting pin for mounting to a said fork. More preferably, the roller assemblies are mounted to the roller housings of the forks, but the roller assemblies may also be mounted to other regions of the forks.

[0063] A piston of a steering cylinder may be connected to a first end of a said mounting pin and may move the first end relative to a second end of the mounting pin. This arrangement may steer the pin about 0.75 degrees off centre. The piston may be connected to the mounting pin in any suitable way. For example, both the first and second ends of the mounting pin may be located within spherical bearings of the fork, and the spherical bearing at the first end may be slidably mounted to the fork.

[0064] In another embodiment, a piston of a first steering cylinder may be connected to a first end of a said mounting pin, and a piston of a second steering cylinder may be connected to a second end of the mounting pin, and as one piston extends, the other piston retracts. This arrangement may steer the pin about 1.5 degrees off centre. Both the first and second ends of the mounting pin may be located within spherical bearings of the fork and both said spherical bearings may be slidably mounted to the fork.

[0065] Preferably, each said roller assembly of the monitoring fork is situated adjacent a said distance monitor. Preferably, the roller assemblies at the forward region of the trolley can be steered independently of the roller assemblies at the central or rearward region of the trolley.

[0066] The electronic control system may enable the steering of the trolley to be carried out automatically or manually. Preferably, the electronic control system automatically activates the drive system to correct the direction of travel of the trolley when the monitoring fork has moved from the pre-set distance from the container sidewalk Manual steering of the trolley may be of importance when precision steering is not necessary or when there is a systems fault with the automatic steering.

[0067] The electronic control system preferably includes a control panel and a display whereby an operator of the trolley may be informed of both the position of the monitoring fork relative to the container sidewall and that the correct direction of steering is being employed. The control panel and display may enable the operator to steer the trolley manually. Any suitable control panel(s) and display(s) may be used. The control panel may be connected to circuitry within a control tower of the trolley by a cable. Alternatively, the control panel may

communicate with a sensor within the control tower using wireless technology, such as infrared light.

[0068] The electronic control system is preferably programmable such that the pre-set distance may be inputted and altered as needed. Preferably, the pre-set distance is programmed by scanning a reflector guard of suitable profile with the distance monitor at the forward region of the monitoring fork. The reflector guard may be positioned outside the container and within the plane of the sidewall, and the reflector guard may have a substantially identical profile to that of the container sidewall.

[0069] The pre-set distance may be defined by a maximum allowable distance and a minimum allowable distance from the container sidewall.

[0070] Since most container sidewalls are corrugated, the reflector guard may also be corrugated, and the corrugated profile will be taken into account when programming the pre-set distance for the distance monitor. Steering may be achieved by periodically taking maximum and minimum distance readings, then taking an average of those readings and steering to a longitudinally extending central plane of the corrugations.

[0071] If the trolley is being propelled by, say, a forklift, then the reverse lights (or other type of warning device activated when reversing) may be operatively connected to the electronic control system for coordination therewith.

[0072] The trolley may include an incremental rotary encoder, operatively connected to the electronic control system for coordination therewith, for monitoring the traveling direction of the trolley, the distance travelled by the trolley and the speed of the trolley. The encoder may be, for example, model number RIB-50-0500-Z-T which is sold by Bell Electronics. The encoder may be connected to a ground-contacting wheel (eg. roller), and as the wheel rotates, the encoder signals the direction of travel and the distance covered by the trolley. By knowing the diameter of the wheel, the encoder also enables the speed of the trolley to be calculated. Such parameters may be displayed on a display of the electronic control system. The wheel may be pivoted out of contact with the ground when the trolley is not in use so as to avoid damage to the encoder. The wheel may be pivotally mounted to a rear end of the trolley. [0073] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[0074] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[0075] Figure 1 is a perspective view from above of a load carrying apparatus in accordance with the present invention;

[0076] Figure 2 is a perspective view from below of the load carrying apparatus shown in figure 1;

[0077] Figure 3 is a perspective view from below showing a roller housing that forms part of the arm or fork of the load carrying apparatus shown in figure 1, with a roller assembly that is mounted in the roller housing being shown separately;

[0078] Figure 4 shows a similar view to figure 3, but with the pin that connects the roller assembly to the roller housing being shown removed and separate to the roller housing;

[0079] Figure 5 shows a side view of the load carrying apparatus shown in figure 1, with the front roller assembly being apart and in line for assembly from the apparatus;

[0080] Figure 6 shows a front view of the apparatus shown in figure 5;

[0081] Figure 7 shows a detailed view of the right hand roller assembly shown in figure 6, with the roller assembly being separate to the roller housing;

[0082] Figure 8 shows a detailed view of the left hand roller assembly shown in figure 6, in which the roller assembly has been mounted to the roller housing;

[0083] Figure 9 shows a load cell circuit diagram showing connection of the various weighing sensors to the controller of the load carrying apparatus shown in figure 1;

[0084] Figure 10 shows a screen report or printout produced by the weight calculator in accordance with an embodiment of the present invention;

[0085] Figure 11 shows a plan view of a load carrying apparatus as shown in figure 1 being ready to load shipping containers;

[0086] Figure 12 shows a plan view of the load carrying apparatus being loaded with a load of cargo and ready to insert the load into shipping container;

[0087] Figure 13 shows the load being moved to the shipping container;

[0088] Figure 14 shows a similar view to that shown in figure 11;

[0089] Figure 15 shows a container loaded with a first shot load and a second shot load being carried on the load carrying apparatus and ready for insertion into the container; and

[0090] Figure 16 shows the second shot load being inserted into the container.

DESCRIPTION OF EMBODIMENTS

[0091] The skilled person will appreciate that the drawings have been provided for the purposes of illustrating preferred embodiments of the present invention. Therefore, it will be understood that the invention should not be considered to be limited solely to the features as shown in the attached drawings.

[0092] Figure 1 shows a perspective view of a load carrying apparatus in accordance with one embodiment of the present invention. The load carrying apparatus 10 shown in figure 1 is of generally similar construction to the load carrying apparatus as described in international patent application numbers WO 03/068658 and WO 03/068659.

[0093] The load carrying apparatus 10 is particularly suitable for loading palletised cargo into containers. The load carrying apparatus 10 has two parallel spaced arms 12, 14. Arm 12 includes roller housings 16, 18. Similarly, arm 14 includes roller housings 20, 22. As best shown in figure 2, roller housing 16 houses a roller assembly 24. The other roller housings 18, 20, 22 also house respective roller assemblies 26, 28, 30. The roller assemblies 24, 26, 28, 30 are as described in in international patent application numbers WO 03/068658 and WO 03/068659, although in those documents, the roller assemblies are described using the terminology "roller housing".

[0094] The arms 12, 14 extend forwardly from a rear frame 32 (see figure 2). A control tower 34 is mounted on the rear frame 32. The control tower 34 houses electronic controls, a programmable logic controller (PLC), hydraulic pumps and hydraulic control circuits and other equipment needed to operate the load carrying apparatus 10. This equipment may be as described in international patent publication number WO 03/068658. The control tower 34 also includes an interface to enable an operator to interact with the control systems. The interface may comprise, for example, a touchscreen, a keyboard, joystick controllers or the like. This particular part of the load carrying apparatus may vary widely and yet still fall within the scope of the present invention.

[0095] Referring now to figure 3, which shows an underneath view of the roller housing 16 with the roller assembly 24 removed therefrom, it can be seen that roller housing 16 includes a recess 36 that has upwardly extending vertical walls, two of which are shown at 38, 40. The recess 36 is sized such that it can house the roller assembly 24. The roller assembly 24 includes side plates 42, 44 that are interconnected by a plurality of cross members, one of which is shown at 46. The side plate 42 includes an opening that receives a bush or bearing 48. Side plate 44 is similarly arranged so that the respective bushes or bearing in side plates 42, 44 are spaced from but in alignment with each other.

[0096] The roller assembly further includes a sub chassis 50 that carries a number of rollers 52, 54, 56, 58, 60 and 62. Roller 56 is mounted via a hydraulic ram 64 that can be extended to cause the roller 56 to move downwardly, rollers 52, 54, 56, 58, 60 and 62 are connected with a tie rod that will in turn cause 52, 54, 56, 58, 60 and 62 to also move downwardly relative to the sub chassis 50. This has the effect of moving the sub chassis 50 upwardly and hence move the roller assembly 24 upwardly. As a result, the upper surface of the arm or fork also moves upwardly.

[0097] Referring now to figure 4, the roller assembly 24 is mounted to the roller housing 16 via pin 66 that extends through openings 68, 70 in the sidewalls of the recess 36. Pin 66 also extends through the bearing or bush 48 mounted in the side plate 42 of the roller assembly. Pin 66 also extends through the bearing or bush mounted in the side plate 44 of the roller assembly 24. In this manner, the pin 66 pivotally mounts the roller assembly 24 to the roller housing 16. As a result, when the load carrying apparatus 10 moves over somewhat uneven ground or uneven surfaces, the roller assemblies can pivot to remain in contact with the uneven ground or uneven surfaces. Figures 7 shows a more detailed view of the roller assembly 24 in position ready to be mounted to the roller housing 16 via pin 66. Figure 8 shows a more detailed view of the roller assembly 24 being mounted to the roller housing 16.

[0098] It will be appreciated that the roller housings 18, 20, 22 have similar roller housings mounted therein using similar mounting arrangements. [0099] As mentioned above, the construction of the load carrying apparatus 10 is essentially similar to the construction of the trolley described in the drawings of international patent publication numbers WO 03/068658 and WO 03/068659. Further details as to the construction of the locally apparatus 10 can be obtained from international patent publication numbers WO 03/068658 and WO 03/068659, the entire contents of which are herein incorporated by cross- reference.

[00100] It will be appreciated that the pin 66 connects the roller assembly 24 to the roller housing 16 (and hence connects the roller assembly 24 to arm 12). Therefore, the weight that is borne by the roller assembly 24 is transferred from the cargo to the roller assembly 24 through the pin 66.

[00101] The load carrying apparatus 10 shown in figures 1 to 8 also includes weighing sensors incorporated into each of the pins that are used to mount the roller assemblies to their respective roller housings. For example, as shown in figure 8, a weighing sensor 72 is mounted into the end of pin 66. This may be achieved, for example, by drilling a hole into the end of pin 66 and mounting the weighing sensor 72 into that hole using a suitable adhesive. In some embodiments, another weighing sensor may be mounted to the other end of pin 66. The weighing sensor 72 may comprise a shear pin load cell. In other embodiments, the weighing sensors may comprise beam load cells, ring torsion load cells, single point load cells, canister load cells, tension load cells, plate load cells and force load cells. It will be appreciated that other weighing sensors may also be used.

[00102] Figure 9 shows a load cell circuit diagram showing how the weighing sensors are connected to the controller. In particular, in figure 9, the weighing sensor 72 is connected via appropriate wiring 74 to a load cell conditioner 76. The load cell conditioner 76 provides a voltage signal to the load cell 72 and return signals are received from the load cell 72. From this, the load cell conditioner 76 provides an output via wires 78, 79 to a PLC controller 80. The PLC controller 80 takes those inputs and then calculates the weight that has been determined by weighing sensor 72. This weight corresponds to the weight that is borne by the pivot pin 66 and the roller assembly 24.

[00103] The other roller assemblies are similarly arranged with weighing sensors. For example, roller assembly 28 is fitted with weighing sensor 82, roller assembly 26 is fitted with weighing sensor 84 and roller assembly 22 is fitted with weighing sensor 86.

[00104] The PLC controller is connected to a monitor or a readout, such as a touchscreen 81 that enables a user to input details of the particular container being loaded with cargo. The PLC controller calculates the weight is determined by each of the weighing sensor 72, 82, 84 and 86.

The PLC controller can then calculate the total weight of the cargo that has been loaded onto the load carrying apparatus 10 and hence loaded into the container.

[00105] Figure 10 shows an example of a screen output 84 that can appear on touchscreen 81 once the apparatus has been loaded with cargo and the cargo weighed. In the example shown in figure 10, the container has a tare weight of 2100 kg. The container is loaded with cargo in five separate shots. The first shot had cargo that weighed 1036 kg. The second shot had cargo that weight 2050 kg. The third shot had cargo that weighed 2607 kg. The fourth shot had cargo that weighed 1183 kg. The fifth shot had cargo that weighed 3772 kg. As can be seen, the total weight of cargo loaded into the container is 12,748 kg.

[00106] When loading the container with multi-shots of cargo, the PLC controller may give the operator the option of manually inputting the number of shots that are to be used.

Alternatively, the loading apparatus 10 may include a position determining device that enables the PLC controller to determine the number of times that the load carrying apparatus 10 has moved into the container. The position determining device may comprise a distance measuring wheel that rolls upon the ground and determines how far the load carried device has moved from a reference position in a certain direction. The distance measuring wheel may be operatively coupled with a distance encoder. In a further embodiment, the loading apparatus includes functionality that detects and verifies when the trolleys have been fully raised and when the trolleys have been fully lowered. Each cycle of raising and lowering constitutes a single loading cycle and therefore this functionality can also determine the number of times at the load carrying apparatus 10 has moved into the container.

[00107] Advantageously, the weight calculator included in the PLC controller 80 also enables the centre of gravity of the load to be determined. Further details of how this is achieved in multi-shot loading of the container will be described with reference to figures 14 to 16.

[00108] As can be seen from figure 10, the screen 84 also allows the date that the container is loaded to be entered (which can occur either automatically or by manual input by an operator). The company responsible for loading the container, in this case ABC Shipping, can also be entered. The container number is entered and the length of the container may either be manually entered or it may be determined from a lookup table or similar that correlates the container number with the physical dimensions and tare weight of the container. Similarly, the tare weight may either be determined from a lookup table or similar, or it may be manually entered by an operator. The screen also includes a button (or a virtual button) that the operator can press when the container is fully loaded. This is the "COMPLETE LOAD" virtual button shown on screen 84 in figure 10. Once the container is fully loaded, the "PRINT" button can be pushed to enable a weighing docket that constitutes written record of the load of the container to be printed. An example of a suitable weighing docket is shown at 86 in figure 10. It can be seen that the weighing docket includes the following information:

- the date that the container was loaded,

- The total weight of cargo loaded into the container and the position of the centre of gravity of the load,

- the container number (#38442),

- the container length (6 m) and the container tare (2100 kg),

- the company responsible for loading the container (ABC Shipping),

- the person or company responsible for weighing the load and the sequence number for this container, and

- the date of last calibration of the weighing sensors.

[00109] It will be appreciated that other information fields may be printed on the weighing docket, if required or desired.

[00110] The weighing docket may be printed onto a sticker that can be adhered to the side of the container. Alternatively, the weighing docket may be printed on paper and placed into a holder having a clear window, which holder is mounted to the side or to a door of the container. In this manner, the weighing docket is readily available for inspection during further handling of the loaded container. The information may also be uploaded automatically or manually to a central database to be accessed by all parties that will encounter or handle this container. The unique identifier or serial number of the container can be entered into this database to retrieve any or all of the information uploaded by the controller.

[00111] Figures 11 to 14 show a diagrammatic view of a container being loaded with cargo in a single shot loading operation. Referring initially to figure 11, the load carrying apparatus 10 is shown. The weighing points, which are effectively determined by the location of load cells 72, 82, 84 and 86, also shown. The virtual centre of the four weighing points is shown at 88. The load carrying apparatus 10 is positioned near the doors of container 90.

[00112] In figure 12, a load of cargo 92 has been positioned onto the arms 12, 14 of the load carrying apparatus 10. The footprint of the load 92 can be seen in figure 12. The centre of gravity of the load 92 is shown at 94. The centre of gravity of load 92 can be calculated by determining the load measured at each of the weighing points 72, 82, 84, 86 and calculating the centre of gravity using a simple algorithm from those measured weights. This algorithm may use the proportion of load measured each of the four weighing points to determine the centre of gravity. Similarly, the total weight of the load is determined by adding the weights determined each of the weighing points 72, 82, 84 and 86.

[00113] Figure 13 shows the load carrying apparatus 10 moving the load 92 into the container 90.

[00114] In order to determine the location of the centre of gravity of the loaded container longitudinally, the location of the load of cargo in the container relative to the container longitudinally must be determined. In order to do this, the load carrying apparatus 10 is provided with a position measuring device. For example, the position measuring device may comprise a distance measuring wheel and associated encoder that rotates as the load carrying apparatus 10 moves into the container and provides information on how far into the container the load carrying apparatus 10 has moved. This enables the location of the centre of gravity of the load in the container longitudinally to be determined

[00115] In order to determine the location of the centre of gravity of the loaded container laterally away from the longitudinal axis of the container, the location of the load of cargo in the container relative to the container laterally must be determined. In order to do this, the load carrying apparatus 10 is provided with one or more position measuring devices. For example, the position measuring device may comprise a distance measuring sensor that sensors the wall of the container as the load carrying apparatus 10 moves into the container and provides information on how far away from the wall of the container the load carrying apparatus 10 is positioned. This enables the location of the centre of gravity of the load in the container laterally to be determined

[00116] The tare weight of the container and the centre of gravity of the container are known and may be labelled on the container. These values and the values of the weight of the load in the centre of gravity of the load can be used to find a combined overall centre of gravity and gross mass for the loaded container.

[00117] Figures 14 to 16 show schematic diagrams of the container being loaded with a multi-shot load of cargo. Figure 14 is essentially identical to figure 11 and need not be described further. In figure 15, a load 100 having a centre of gravity located at 102 has already been loaded in a first shot into the container. A second load 104 has been loaded onto the load carrying apparatus 10 and is ready to move to the container. The centre of gravity 106 of the load 104 can be determined from the proportion of weight at each of the weighing points 72, 82, 84, 86. In figure 16, the second load 104 has been moved into the container. The position of the second load in the container can be determined from the distance measuring wheel and from steering sensors or other sensors that can determine the distance from container walls to the weighing sensors and therefore the location within the container of the centre of gravity of the second load in both the longitudinal direction and in the lateral direction can also be determined. From the total weight of the first load 100 and its position of centre of gravity within the container, the total weight of the second load 104 and its position of centre of gravity in the container and the tare weight of the container and the position of the centre of gravity of the empty container, it is possible to determine the total weight of the loaded container and the overall centre of gravity of the loaded container.

[00118] The present invention provides a load carrying apparatus that enables cargo to be loaded quickly and efficiently into a container. The cargo may comprise cargo that is loaded onto pallets. The load carrying apparatus of the present invention allows for the weight of the cargo loaded into the container to be determined using weighing sensors that are included in or on the load carrying apparatus. In some embodiments, the total weight of the cargo that is carried on the load carrying apparatus and the position of the centre of gravity of that load can be determined. The gross weight of the loaded container and the overall centre of gravity of the loaded container can also be determined in some embodiments. A PLC controller or a computer can be used to receive information from the weighing sensors and to determine the weight of each load of cargo loaded into the container, the centre of gravity of each load of cargo loaded into the container, the total weight of cargo loaded container and the overall centre of gravity of the loaded container to be determined. All relevant information can be printed to form a written record that can be attached to the container and relevant regulations requiring information relating to the weight of a container to accompany the container can be met. The apparatus may send data relating to a loaded container to a central database and all parties that come into contact with the container all have to handle the container whilst it is loaded can access that information from the central database.

[00119] In most uses of the present invention, the load will be supported on pallets and the arms or support platform will be inserted into the pallets and raised to lift the load and support the load on the arms or the support platform. The weight and centre of gravity of the load on the arms or support platform can then be determined. Once the load has been placed in the container, the upper surface of the arms or support platform can be lowered so that the pallets rest on the floor of the container and the arms or support platform can be withdrawn from the container.

[00120] In the present specification and claims (if any), the word 'comprising' and its derivatives including 'comprises' and 'comprise' include each of the stated integers but does not exclude the inclusion of one or more further integers.

[00121] Reference throughout this specification to 'one embodiment' or 'an embodiment' means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases 'in one embodiment' or 'in an embodiment' in various places throughout this specification are not necessarily all referring to the same embodiment.

Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[00122] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any)

appropriately interpreted by those skilled in the art.