DETECTION SYSTEM AND METHOD Field of the Invention The invention relates to the transporting of bulk materials and is, in particular, directed to a bulk material transport device such as spreaders arranged to engage and rotate a container or a grab for digging and unloading the bulk material into the hold of a ship for subsequent transport. Specifically, the invention is directed to a safety detection apparatus and method to prevent the premature unloading of said bulk material.

Background

Spreaders used for bulk material containers, otherwise known as a "revolver", operate by engaging such a container and moving it to the hold of a ship before rotating the containers so as to empty the bulk material into the hold. An alternative bulk material transport device is the "grab" which is arranged to dig into the bulk material, for example using a clam grab which acts as a co-operating pair of jaws. In both case, the bulk material transport devices, or assemblies, lack a system that will ensure that the material is released on when the predefined hold.

For the spreader, this variety of device, like standard container spreaders, includes mechanical and electrical systems to prevent the disengagement of the twist locks to the container when the spreader is in mid-air. However, there is no similar safety system for ensuring the revolver does not rotate the container so as to unload the bulk material away from the ship's hold. Accordingly, it is possible for an operator to mistakenly trigger the rotation of the container at any point, once engaged, and not merely within the ship's hold. The consequences of the disruption to the dock, and the subsequent property damage and potential loss of life, are clear.

It would therefore be advantageous to include a safety system that would only allow the release of the bulk material at a location meeting specific criteria such as within a defined hold.

Summary of Invention

In a first aspect the invention provides a detection system for a bulk material transport device comprising: at least one emitting sensor; a target; a processor in communication with said at least one emitting sensor; wherein the emitting sensor is arranged to identify the target and communicate a notification to the processor, with the processor arranged to allow unloading by the bulk material transport device if the result meets a predetermined result.

In a second aspect the invention provides a method for determining safe unloading of a bulk material transport device comprising the steps of: emitting a signal from said transport device; identifying a target based on said signal; communicating a result to a processor; comparing the result to a required predetermined result, and; allowing unloading by the transport device if the result is consistent with the required predetermined result. Therefore, the invention provides for the use of emitting sensors to identify a target. On identification, the positive result is communicated to the processor which determines whether the container can be rotated for unloading.

In one embodiment the target may be a passive target in that it does not communicate a signal back to the emitting sensor. An example of a passive target may include a purpose built fixture mounted onto the ship, the edge of the ship's hold or other physical element. In this case, the emitting sensor may include an optical or ultrasonic distance sensor for determining the distance from the spreader to the physical element.

In an alternative embodiment, the target may be an active target in that on receiving a signal from an emitting sensor, it communicates a signal back to the emitting sensor. For example, the active target may be a pulse generator that is arranged to communicate an ID back on being interrogated by the emitting sensor signal. The emitting sensor may then communicate the notification to a processor for comparison with a predetermined notification. If the notification and predetermined notification do not match then unloading is prevented. Alternatively, if the notification's match, the processor may permit unloading of the spreader on the basis that the interrogated pulse generator has yielded a notification corresponding to a safe unloading site. In one embodiment, the emitter may be mounted either near to the hatch or to the revolver. Alternatively, the target may be mounted either near to the hatch or to the revolver.

Brief Description of Drawings

It will be convenient to further describe the present invention with respect to the accompanying drawings that illustrate possible arrangements of the invention. Other arrangements of the invention are possible and consequently, the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.

Figure 1 is an isometric view of a docked ship receiving bulk material from a container mounted to a revolver;

Figure 2 is an isometric view of an active target arrangement according to one embodiment of the present invention;

Figure 3 is an isometric view of a passive target arrangement according to a further embodiment of the present invention;

Figure 4 is an isometric view of a revolver having a detection system according to one embodiment of the present invention; Figures 5A and 5B are various views of a detection system according to a further embodiment of the present invention;

Figure 6 is a schematic view of the sensor patterns of a detection system according to a further embodiment of the present invention;

Figures 7A to 7C are various view of the sensor pattern of a detection system according to a still further embodiment of the present invention. Figure 8 is an isometric view of a docked ship receiving bulk material from a grab mounted on ship crane;

Figures 9A and 9B are various views of a detection system according to a further embodiment of the present invention;

Figure 10 is an elevation view of a detection system according to the present invention according to a further embodiment of the present invention;

Figures 1 1 A to 1 IF are various views of a lid lifting detection system according to one embodiment of the present invention;

Figures 12A to 12C are various views of a lid lifting detection system according to a further embodiment of the present invention, and; Figures 13 A and 13B are isometric views of a hopper and grab according to a further embodiment of the present invention.

Detailed Description

In general the invention includes a system for a bulk transport device, whereby an emitter identifies a target by sending an interrogation signal to the target. The result of the interrogation is then sent to a processor. If the results meet a pre-determined result, the processor will allow unloading of the bulk material by the bulk material transport device.

For a passive target, the result may be a distance measured by the emitter's signal. The pre-determined result may then be an allowable distance. If the result is a distance within the tolerance of the pre-determined result/allowable distance the device will be permitted to unload.

Alternatively, the target may be active and emit a notification on receiving the interrogation signal, the notification being the result to be communicated to the processor. The processor will then compare the notification with a pre-determined notification, which may be a code corresponding to the ship or to the hold of the ship. If the notification and pre-determined notification match, the device will be permitted to unload. Figure 1 shows a typical arrangement of a ship 5 alongside a dock 10. Quayside cranes 15 are used to manoeuvre bulk material transport devices, in this case, container spreaders 20, for the loading of bulk material to the hatch 25 of the ship 5.

Figure 2 shows one embodiment according to the present invention. The sheaves, cables and crane have been omitted for clarity. One form of a bulk material transport device includes a bulk material container spreader, to be referred to as a "revolver" 20, is placed within the hatch 25 and in particular, within the opening or hold 35. Located near the hatch 25 is an active target, in this case, a pulse generator 7 arranged to receive a low frequency signal 13 from emitting sensors, in this case, antennae 9, 1 1 mounted to the revolver 20. On being interrogated by the low frequency signal, the pulse generator 7 transmits 17 a notification back to the emitting sensors of the revolver 20. If the notification received by the emitting sensors/antennae matches a predetermined notification, and so positively identified by a processor or micro controller on the revolver 20. then the micro controller will permit the rotation of the container and so empty the container into the hold hatch 25.

Figure 3 shows a similar arrangement of a ship's hatch 25 having a spreader 20 within the hatch 25. As seen in Figure 4, 5 A and 5B, the spreader 20 includes emitting sensors which, in this case, arc distance sensors installed at a lower part of the spreader 20. The distance sensors are arranged to detect the distance to a solid object in multiple directions 40, and so identify the location of the passive target (hold walls or hatch wall) and communicate this location to the processor for comparing with a predetermined location to determine whether unloading should be permitted or not. As shown in Figure 4, a recess 55 is located at one end 45 of the spreader 20 with a similar recess at an opposed end 50. Figures 5A and 5B show further recesses 60 located at the side. Each of the sensors 65, 70, 75, 80 transmits a sensing field in order to determine the distance to a solid object. In the present case, the target is a passive target and includes the walls 30 of the hatch 25 or possibly the walls of the hatch 25, which form a physical barrier for the sensing field. On detecting the walls within the sensing field, and so the location of the walls within an acceptable degree of tolerance, each emitting sensor communicates this location information to the processor, such that the walls of the hatch 25 are within a certain distance from the spreader. Taking all the communicated information from all the emitting sensors, and so determining which emitting sensors have identified a target within the predetermined location, the processor will then determine whether to allow rotation of the container by the revol ver.

Whether the embodiment shown in Figure 2 or the embodiment of Figure 3 is selected by a user will depend upon the specific application with both demonstrating advantages.

The active target embodiment of Figure 2 may allow for the spreader to be used only in the designated hold. For instance, there may be a circumstance whereby a particular container load can only be placed in a specific hold. By having an active target which transmits a notification corresponding to that of the processor, then an operator cannot mistakenly place the contents of the container in the wrong hold. The necessity for having the correct notification received on interrogation by the emitting sensors prevents the spreader rotating without confirmation of the correct notification. This, for instance, may be particularly useful for loading a series of ships to ensure the correct material is placed in the correct ship.

Figure 3 may be advantageous when a ship merely needs to be loaded and the particular container content is not specific to a particular hold. The embodiment of Figure 3 only requires that the emitting sensors detect the presence of the hatch through the passive target of the walls 30 of the hold. Thus, it is a much simpler system to adapt for applications requiring less complexity. Figures 6, 7 A, 7B and 7C show further advantages through the passive target embodiment. Figure 6, in particular, shows 12 distinct sensing fields with sensing fields 1L to 8L arranged for long sensing distances, for instance, say 18 metres. Sensing fields I S to 4S are arranged for a much shorter range, for instance, say 3 metres. In the present embodiment shown for Figure 6 long sensing fields 5L to 8L may be redundant and so provide an additional marginal safety.

In the schematic of Figure 6, the outline of the hatch 100 is intersected by the long sensing fields 105, 1 1 5 but not by the short sensing field 1 10. In this arrangement the processor within the spreader 95 may determine that there are passive targets intersecting all of the long sensing fields and so within in this embodiment, 18 meters. If the predetermined criteria for the processor are that all long sensors intersect targets, then this will be sufficient to release rotational operation of the revolver. However, none of the short sensing fields are intersected indicating the spreader 95 is located within a boundary of greater than 3 metres but less than 18 metres. It will be appreciated that the length of the respective sensing fields can be adjusted for typical aperture sizes of the hatch 100 for the ship ^' s hold.

Having intersected all of the long sensing fields the processor can determine that it is likely the spreader is within the ship's hold and therefore it is free to unload the container.

Alternatively the sensor may detect the actual distance of the revolver from the target and communicate to processor and predetermined criteria can be based on the distance information.

Shown in Figures 7A to 7C are various arrangements in which the sensing arrangement identify the alignment of the container with respect to other containers within an array, and so preventing premature rotation.

In Figure 7A if the container 1 16 is within an array of containers at a corner, then a face A of the container 1 16, and so the long sensors 21.. 31 , and 61, along with the short sensors 2S and 3S will all be triggered. None of the remaining long or short sensors will be triggered. The processors will then determine that the spreader is very close to two passive targets correspondin to 2S and 3S but is a considerable distance on all other sides from any other passive target. In the circumstance, the revolver will be prevented from unloading. In Figure 7B, if the container 1 17 is in the middle of an array of containers having one face B exposed, then long sensors 2L, 3L, 4L, 6L and 7L together with short sensors 2S, 3S and 4S are all triggered with the remaining long and short sensors not detecting any passive targets. Once again, the revolver will be prevented from rotating.

In the last embodiment of Figure 7C, where the container 1 18 lies within an array of containers and having only an upper face C exposed, then all the sensors, both long and short, are triggered and consequently the processor will determine that it is not within a ship's hold and therefore is prevented from unloading the container.

Accordingly, the use of long and short sensors can detect boundary conditions including where a container may be offset from the centre of a ship's hatch. If short sensors on one or two sides have been triggered but not on the others, whilst all of the long sensors have been triggered, then the processor may have a predetermined criteria that interprets this as corresponding with a ship's hatch.

The operator may wish to eliminate this as a suitable predetermined criterion by shortening the long sensors so that in an abundance of caution only centrally placed spreaders may be permitted to unload. Therefore, in terms of management the operator may also control offset based upon the level of confidence held for the crane operators.

Figure 8 shows a bulk earner 5 similar to that of Figure 1. Here the loading and the unloading of bulk material is achieved from a ship mounted crane 125 supporting a grab 130 in this case a double clam shell grab. The ship mounted crane 125 is mounted adjacent to a hatch 25 whereby material is lifted by the grab 130 and deposited in the hatch 25 from the wharf.

Figures 9A and 9B show an alternative arrangement whereby a crane suspended grab 135 is lowered into the hatch 25 by a quayside crane (not shown). As the grab falls within the definition of a bulk material transport device, the detection system 140 according to the present invention is equally applicable to this arrangement as it is for a revolver spreader. In the case shown in Figures 9A and 9B, a device mounted sensor arrangement emits an interrogation signal 140 in order to detect the presence of a target as previously described.

Figure 10 shows a further embodiment whereby the bulk material detection system includes a downwardly projecting sensor to emit interrogation signals downwards. For illustrative purposes the device of Figure 10, includes a spreader 145 within a hatch 25 for unloading bulk material 160. As before, sensor interrogation signals 140 are emitted in order to ensure the spreader is in the designated hold. It should be noted that the sensors may be distance sensors whereby the interrogation signal determines the distance to the walls, said walls acting as the target. In this embodiment, there are downward projecting sensors 150 so as to emit a downward projecting interrogation signal 155 with the passive target being the surface of bulk material 160 within the hatch 25. This may provide a safety feature to ensure the device is not lowered too low into the hold and so impact the surface of the bulk material. The processor may also have a clearance requirement. For instance, the revolver may be a set height above the surface, such as 4 metres for instance, before the revolver is permitted to unload the material.

For application to the grab (not shown), the downward sensor may allow a more precise lowering of the grab in order to engage the surface. Thus, for both devices the downward sensor may be used to prevent contact with the surface. .

In a further embodiment, with an additional downward projecting emitting sensor, the degree to which the hold has been filled may also be determined based upon the distance from the spreader 145 to the top surface of the bulk material 160. Thus, in this embodiment the detection system may be further enhanced by providing an assessment as to the progressive capacity of the hold as it is filled with the bulk material from the spreader 145. By sending an interrogation signal downwards, the surface of the bulk material can be detected. As the hold is filled, the surface rises, with the detection system detecting and recording the rise in the surface and consequently measuring the rate of fill of the hold. Hus the operator can, through the detection system identify when the hold is filled without directly looking inside the hold.

Figures 1 1 A to 1 I F, and Figures 12A to 12C, show a further aspect of the present invention whereby a lid detection sensor 180 is mounted to a spreader 175. The purpose of the sensor 180 is for application to a revolver spreader engaging a container 165, and more particularly, the container 165 having a lid 170. As a further safety feature, an LDS system detects the presence or absence of the lid cover on the container. When the lid cover is present, the processor will prevent rotation of the container 165 until the lid 170 has been lifted by a mounted lid lifting device 185. Once lifted clear of the container, the processor will allow rotation of the revolver and unloading of the container.

It will be appreciated that the lid Detection sensor may be used with or without the detection system described with reference to Figures 1 to 10. Thus it may be a separate system, or an additional system in communication with the same processor of the detection system.

In sequence, the revolver engages the container 165 having a lid 170, as shown in Figures 1 1C and 12 A. The lid is engaged by the lifter 185 and lifting is commenced as shown in Figure 1 ID. Throughout this process, the lid detection system, through the lid sensor 185 prevents the rotation of the revolver unt i l fully lifted.

Once the lid reaches the desired clearance height as shown in Figures 1 IE and 12C, the lid detection sensor senses the proximit of the lid, and communicates tis to the processor, which then releases t he revolver allowing rotation of the container.

In an alternative arrangement, Figures 13A and 13B indicate the application of the invention for use with a quayside hopper 205 into which a grab 195 mounted to a ship's crane 190. Here a ship 185 has docked with the quay 200 and has commenced unloading ofthebulk material through use of a ship mounted crane 190. The bulk material is removed from the hold 192 using a grab 195 mounted to the crane 190 and placed within a hopper 205 positioned on the quay 200. The hopper 205 is then arranged to load trucks (not shown) that drive under the hopper to receive the bulk material.

As with the earlier embodiments, it is critical that the grab does not release the bulk material prematurely, and so sensor and processor arrangements as previously described are equal applicable to the current arrangement, whereby the target is now in the form of the hopper 205 rather than a hatch or hold of the ship.