Field of the Invention

[0001 ] The present invention relates to the weighing of shipping containers, particularly when located atop a vehicle such as a transporting trailer.

Background to the Invention

[0002] The transportation of goods within shipping containers is

commonplace around the world. Such containers are designed to be readily lifted and moved into position, with the ability to be stacked one-on-another for storage or for long journeys, such as across oceans.

[0003] For shorter journeys, such as from a local destination to a port, shipping containers are generally located atop a trailer being pulled by a prime mover or tractor unit..

[0004] Shipping containers are typically formed with steel corner castings which extend outwardly from the container. The corner castings serve several functions. They are arranged to collectively support the entire weight of the shipping container and help in maintaining structural integrity. In addition, they provide an efficient means of stacking several containers vertically. They provide suitable lifting points to allow safe movement of the container, as well as providing anchoring points for securing the container during transport.

[0005] It is frequently desirable to know the weight of a shipping container being transported. Traditionally, this has been determined by driving a vehicle carrying the container onto a fixed weighbridge, and then calculating the weight of the container(s) on board by subtracting the known tare weight of the vehicle.

[0006] There are several undesirable aspects to the use of fixed

weighbridges to determine the weight of a shipping container. Principal among these is the need to drive the vehicle to a suitable fixed weighbridge at least once, if not twice (once to determine tare weight, once to determine loaded weight). Where the weighbridge is located away from the vehicle's route, the travelling to-and-fro from the weighbridge adds both time and expense to the transport operation.

[0007] The use of mobile weighbridges or similar platforms may reduce the time lost, but can add significant expense to a transport operation.

[0008] The information gained from a weighbridge is also limited. The best that can be achieved is knowledge of the gross weight of all containers loaded on a vehicle. Where more than one container is being transported, it is generally not possible to identify individual weights. It is still more difficult to identify load distribution within a single container.

[0009] In an attempt to partially address these problems, there has been a movement towards installing Onboard' weighing systems within the chassis of container-transporting vehicles.

[0010] Known on-board systems generally work on the principle that the weight supported by a vehicle must be ultimately supported by the axles of the vehicle. Providing a means of determining the load being carried by each axle group allows for an on-board calculation of total load. Where the vehicle is a trailer being drawn by a prime mover or other towing vehicle, the load from the trailer that is transmitted through the towing vehicle axles may be determined by a load measuring system associated with the towing vehicle's coupling.

[001 1 ] Such a system also has limitations. Where more than one container is being transported, the system can only identify individual container weights during loading or unloading operations, which may not be practical. There is no way of accurately determining load distribution within a container. In addition, such systems generally require both a trailer and a towing vehicle to have compatible weighing systems installed. [0012] An alternative arrangement has been proposed whereby load cells are incorporated into the trailer as part of a system for anchoring a container onto the trailer. While this may allow for relatively accurate weighing of a container, their existence makes the easy anchoring of a container to a trailer relatively difficult. In particular, the presence of such load cells makes the use of a preferred 'twistlock' locking arrangement problematic.

[0013] The present invention seeks to provide a system which at least partially addresses some of these concerns.

Summary of the Invention

[0014] According to one aspect of the present invention there is provided a means for supporting a container on a vehicle, the means including a plurality of load supporting structures, the load supporting structures being arranged to receive a corner of a supported container and to transfer the weight of that corner to a chassis of the vehicle, the load supporting structures each having an anchoring means moveable between a lowered position outside the corner of the supported container and a raised position in which the anchoring means locates at least partially within the corner of the supported container, wherein each of the load supporting structures is associated with a load sensing means

[0015] Advantageously, this allows for accurate weighing of the container, without interference with the operation of the anchoring means.

[0016] The load supporting structure preferably includes load bearing members which support the container, and load bearing beams which transfer the load from the load bearing members to the vehicle chassis.

[0017] According to a second aspect of the present invention there is provided a means for supporting a container on a vehicle, the means including a plurality of load bearing members, each of the load bearing members being arranged to support a corner of a supported container, at least one of the load bearing members incorporating a load sensing means, the load bearing members being associated with an anchoring means, the anchoring means being moveable between a lowered position outside the corner of the supported container and a raised position in which the anchoring means locates at least partially within the corner of the supported container

[0018] It is preferred that each of the load bearing members is arranged to support a corner casting of a supported container.

[0019] There may be four load bearing members, each one associated with a corner of a supported container.

[0020] The arrangement is preferably such that the load bearing members locate, in use, between a supported container and a chassis of the vehicle, such that the full load of the container must pass through the load bearing members to the chassis.

[0021 ] In a preferred embodiment, when in its raised position the anchoring means may be moveable between an open position and a locked position, such as by rotation. The anchoring means may be a 'twistlock'. The load bearing members may be positioned annularly about the anchoring means, or may alternatively be located adjacent to the anchoring means.

[0022] The system of the present invention may be deployed on a skeletal trailer, the skeletal trailer having longitudinal main structural beams and transverse load bearing beams. On such a trailer the system may be deployed with each load bearing member fixed atop a load bearing beam. It is anticipated that the load bearing member will be located outside the main structural beams.

[0023] It will be appreciated that the load bearing members may be incorporated within the vehicle at the time of vehicle manufacture.

Alternatively, the load bearing members may be added to an existing vehicle in a 'retro-fit' operation. [0024] According to a second aspect of the present invention there is provided a means for determining a load placed by a container on a vehicle, the vehicle including a plurality of load bearing beams, each beam being arranged to support at least one corner of a shipping container, each beam being arranged to mount to a chassis of the vehicle, the means including a load sensing means located between the corner of the shipping container and the vehicle chassis.

[0025] The load sensing means may be arranged to determine the deflection of the load bearing beam under the weight of the shipping container.

[0026] In one embodiment, the load sensing means may be located centrally on a beam, and arranged to determine the load from two corners of the shipping container. In an alternative embodiment, each corner may have a load sensing means associated therewith.

Brief Description of the Drawings

[0027] It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:

[0028] Figure 1 is a side view of a skeletal container-supporting trailer incorporating the load sensing apparatus of the present invention;

[0029] Figure 2 is a plan view of the trailer of Figure 1 ;

[0030] Figure 3 is a plan view of a load bearing beam within the trailer of Figure 1 ;

[0031 ] Figure 4 is a front view of the load bearing beam of Figure 3; [0032] Figures 5(a) to 5(c) are sequential front views of a twistlock anchoring arrangement of the prior art.

[0033] Figure 6(a) is a front view of the twistlock of Figure 5, shown in a locked configuration;

[0034] Figure 6(b) is a front view of a twistlock from the load bearing beam of Figure 3, shown in a locked configuration;

[0035] Figure 7(a) is a front view of a second embodiment of a load sensing apparatus in accordance with the present invention, shown in position at an end of a load bearing beam from within a skeletal container- supporting trailer;

[0036] Figure 7(b) is an end view of the load sensing apparatus of Figure

7(a);

[0037] Figure 8(a) is a plan view of a third embodiment of a load sensing apparatus in accordance with the present invention, shown in position at an end of a load bearing beam from within a skeletal container-supporting trailer;

[0038] Figure 8(b) is a front view of the load sensing apparatus of Figure 8(a);

[0039] Figure 8(c) is an end view of the load sensing apparatus of Figure 8(a);

[0040] Figure 9 is a front view of a fourth embodiment of a load sensing apparatus in accordance with the present invention, shown in position at an end of a load bearing beam from within a skeletal container-supporting trailer.

[0041 ] Figure 10 is a front view of a fifth embodiment of a load sensing apparatus in accordance with the present invention, shown in position at an end of a load bearing beam from within a skeletal container-supporting trailer.

[0042] Figure 1 1 is a front view of a sixth embodiment of a load sensing apparatus in accordance with the present invention, shown in position at an end of a load bearing beam from within a skeletal container-supporting trailer.

[0043] Figure 12 is a front view of a seventh embodiment of a load sensing apparatus in accordance with the present invention, shown in position at an end of a load bearing beam from within a skeletal container-supporting trailer.

[0044] Figure 13 is a front view of an eighth embodiment of a load sensing apparatus in accordance with the present invention, shown in position at an end of a load bearing beam from within a skeletal container-supporting trailer;

[0045] Figure 14 is a front view of a ninth embodiment of a load sensing apparatus in accordance with the present invention, shown in position midway along a load bearing beam from within a skeletal container- supporting trailer;

[0046] Figure 15 is a front view of a tenth embodiment of a load sensing apparatus in accordance with the present invention, shown in position midway along a load bearing beam from within a skeletal container- supporting trailer;

[0047] Figure 16 is a front view of an eleventh embodiment of two load sensing apparatuses in accordance with the present invention, shown in position at either end of a load bearing beam from within a skeletal container-supporting trailer; and [0048] Figure 17 is a front view of a twelfth embodiment of a load sensing apparatus in accordance with the present invention, shown in position along a load bearing beam from within a skeletal container-supporting trailer.

Detailed Description of Preferred Embodiments

[0049] Referring to the Figures, Figures 1 and 2 show a skeletal trailer 10 having a front end 12 and a rear end 14. Two longitudinal main structural beams 16 extend from the front end 12 of the trailer 10 to the rear end 14. The main structural beams 16 are transversely spaced from each other.

[0050] The trailer 10 includes a plurality of transverse load bearing beams 18. The load bearing beams 18 each extend from an outer position on one side of the trailer 10 to a corresponding outer position on the other side of the trailer 10, crossing through and being supported by the main structural beams 16.

[0051 ] The trailer 10 includes other structural elements such as axles 20 and cross bracing which are in accordance with standard construction techniques.

[0052] The load bearing beams 18 each extend a distance equal to the width of a standard shipping container, that is, about 2.4m.

[0053] The load bearing beams 18 are suitably spaced along the main structural beams 16 so as to be in position to receive the cast corners of shipping containers. In the arrangement of Figures 1 and 2 there are a total of six load bearing beams, being arranged in three nominal sets: a first set with a front beam 18 located at the front end 12 of the trailer 10 and a rear beam 18 located centrally of the trailer 10; a second set with a front beam 18 located immediately to the rear of the rear beam 18 of the first set, and a rear beam 18 located at the rear end 14 of the trailer 10; and a third set with a front beam 18 located midway between the beams 18 of the first set and a rear beam located midway between the beams 18 of the second set. The front and rear beams 18 of each set are spaced about 6m apart. [0054] This configuration allows for loading of the trailer 10 in several ways. Two 20ft containers can be loaded end-to-end, one on each of the first and second sets of load bearing beams 18. A single 20ft container can be loaded on the third set of load bearing beams 18. A single 40ft container can be loaded using the front-most load bearing beam 18 and the rear-most load bearing beam 18. A 30ft container can be loaded suing the front beam 18 of the third set and the rear beam 18 of the second set.

[0055] Each of the load bearing beams 18 has a container anchoring means associated with it, one located at each end of the load bearing beam 18. In the embodiments of the drawings the container anchoring means is a standard twistlock 22.

[0056] The operation of a twistlock 22 is shown in Figure 5. Each twistlock 22 has a vertical shaft 24 which extends through a housing 26, and which is topped by generally rectangular head 28. A handle 30 extends beneath the housing 26. The handle 30 can be used to raise the twistlock 22 from a lowered position shown in Figure 5a to a raised position shown in Figure 5b. In the raised position the handle can be used to rotate the head 28 between an open position as shown in Figure 5b and a locked position as shown in Figure 5c. The arrangement is such that a container can be located atop the housing 26, and then the head 28 raised within an aperture of a container cast corner, before being rotated so as to lock the cast corner into position relative to the load bearing beam 18.

[0057] The key to the present invention lies in the realisation that the entire weight of a shipping container passes through the cast corners into the chassis of the trailer 10.

[0058] In its simplest form, the present invention has load bearing members in the form of load cells 32 associated with each twistlock 22. Two such load cells 32 can be seen in Figures 3 and 4. Each load cell 32 is located atop a mounting pedestal 34 welded or otherwise fixed to an end of a load bearing beam 18. The load cell 32 has an uppermost surface 36 which is higher than the load bearing beam 18. The load cells 32 are positioned such that when a shipping container is located with a cast corner aperture correctly aligned with a twistlock 22 the cast corner locates atop the associated load cell 32. As the load cell 32 is higher than the surrounding structure, the entire weight of the corner of shipping container is supported by the load cell 32.

[0059] Figure 6 shows the contrast between a traditional arrangement of the prior art, shown in Figure 6a, and the present invention shown in Figure 6b

[0060] The load cell 32 incorporates a load sensing means, which is typically a strain gauge located through an electrical entry 38. The load sensing means can determine the load passing through the load cell 32 to the mounting pedestal 34; that is, the weight of the container corner. It will be appreciated that other load sensing means, such as an optical Fiber Bragg Grating, may be employed.

[0061 ] Each load cell 32 has an electrical output 40. Suitable electronic means are used to provide the information from the outputs 40 of all load cells 32 to a display means (not shown). In a preferred form of the invention, this output is provided wirelessly (for instance via Bluetooth) to a suitable display device, which may be a cell phone app. Alternatively, the output may be provided by wired connection to a display means on the vehicle chassis, in the cabin of the towing vehicle, or transmitted to a remote location.

[0062] It will be appreciated that the total weight of a shipping container will be the sum of the weight transferred through its corner castings. Suitable identification of the relevant load cells 32 allows for ready calculation of this weight.

[0063] It will further be appreciated that the weight distribution within a shipping container will be demonstrated by the relative loads passing through each of the four corners. Comparison of these values will quickly indicate an uneven load distribution within the container.

[0064] The load bearing members may be arranged in alternative

configurations. Figures 7a and 7b show an alternative load cell arrangement 50 which formed by two load cells arranged in a C-shaped configuration, located around an upper surface of the housing 26 of the twistlock 22.

[0065] Figures 8(a) to 8(c) show another alternative load cell 52 which is cylindrical, and locates above the housing 26 of a twistlock 22.

[0066] Figure 9 shows a further embodiment where a load cell 54 is welded to the side of the housing 26 of a twistlock 22, with the load cell then being bolted to the load bearing beam 18.

[0067] Figure 10 shows another alternative load cell 56 which is bolted between the housing 26 of the twistlock 22 and the load bearing beam 18. In this embodiment the full weight of the container is taken by the housing 26 of the twistlock 22, with the load being determined by the load cell 56 as it is transferred to the load bearing beam 18.

[0068] Figure 1 1 shows an alternative embodiment of the present invention, whereby a load cell 58 is mounted to a lower surface 60 of the load bearing beam 18 midway between its outer end and the main structural beam 16. This embodiment relies on the realisation that a load transmitted through the cantilevered end of the load bearing beam 18 will cause bending of the load bearing beam between its mounting point on the main structural beam 16 and its free outer end. The load cell 58 is positioned to measure this bending (as compression).

[0069] Similar concepts are shown in Figures 12 and 13, where a load cell 64 (Figure 12) or 66 (Figure 13) is mounted to an upper surface 62 of the load bearing beam 18, and positioned to measure bending as tension (Figure 12) or bending (Figure 13). [0070] Figure 14 shows an extension of this context, whereby a single load cell 68 is positioned centrally on the upper surface 62 of the load bearing beam 18. It will be appreciated that this load cell can be calibrated to measure bending of the load bearing beam 18 between the main structural beams 16. As such, it can be calibrated to determine the total load being supported by the load bearing beam 18, that is, the sum of the loads supported by the twist lock housings 26 at either end.

[0071 ] Figure 15 shows a similar arrangement to Figure 14, with a single load cell 70 being positioned on a central web 72 of the load bearing beam 18, and arranged to measure its deflection.

[0072] Figure 16 shows a similar arrangement to Figure 13, with load cells 74 being mounted to the web 72 of the load bearing beam 18 rather than to the upper surface 62.

[0073] A still further embodiment is shown in Figure 17. In this embodiment a load cell 76 is located between the lower surface 60 of the load bearing beam 18 and a lower flange 78 of the main structural beam 16. This load cell is arranged to detect the vertical load being transmitted from the load bearing beam 18 to the main structural beam 16.

[0074] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.