TECHNICAL FIELD

The present invention relates generally to the handling of bulk materials, such as ore, coal, grain etc., for shipping purposes. More particularly, the present invention relates to an improved system to handle containers where side access is limited.

BACKGROUND TO THE INVENTION

For many years, bulk materials have been loaded into the holds of ships by the use of conveyors and grapples that cannot load containers effectively or have restricted loading mechanisms which cannot deliver material to a desired location. This is expensive, requires setup time and is slow and complex to handle. For that reason, it is preferred to use standard cargo containers of the type that are hoisted and located by the use of a gantry cantilevered crane. This provides many advantages, including the ability to load and off-load cargo containers from various transport means, including flat-bed trucks and rail cars. Another benefit is that the bulk material within the containers is protected from the environment and, in turn, the environment is protected from the bulk material (possible pollutants).

A further advantage is that containerisation permits much more precise positioning of the material within the hold compared to conveying bulk material in loose fonri. Even if the bulk material is to be tipped into the hold, the use of containers allows much more precise loading of the material.

US Patent No. 4,496,275 discloses a tipping adapter that permits a cargo container, which is suspended from a hoisting device (such as a gantry cantilever crane), to be selectively tipped about an axis extending longitudinally through the container so that bulk material, such as coal, grain etc., may be tipped from the container into a ship's hold or other receiving space. The adapter includes a drive support frame which connects to the crane or a crane -supported container spreader at the connection points normally used in connecting the container to the spreader. A pivotal frame connects to a container in the same manner in which the spreader connects to the container. The drive support and pivotal frames are pivotally engaged so that one or more drive motors, mounted on the drive support frame, can be used to selectively pivot the pivotal frame and thereby tip the container. Controls are placed at the crane control panel to permit selective container engagement and tipping, and interlocks are provided to prevent tipping of the container before it is properly engaged.

A difficulty with the above-mentioned tipping adapter is that at least some of the drive mechanisms and the frame need to extend on each side of the container. When the containers are packed tightly in a horizontal plane (for example; when they are delivered by train), the apparatus cannot engage a container because there is insufficient room to accommodate the tipping adapter. This relates to picking up a container either from the hold of a ship to be tipped out or hoisted from the flat bed of a rail car and tipped out into the hold of a ship.

SUMMARY OF THE INVENTION

The present invention relates to apparatus for delivering bulk material from a cargo container to a designated area by tipping the cargo container.

In a broad aspect, the invention relates to apparatus for engaging and handling a cargo container, said apparatus having a frame assembly including:

a longitudinal support member;

two spaced apart sub-frames depending from the longitudinal support member;

each sub-frame having a container support arm pivotally mounted by means of a rotating assembly on its inner face, said rotating assembly connecting the sub-frame to its respective container support arm;

a drive means to rotationally drive the rotating assembly connecting the sub-frame to its container support arm; and

each container support arm including one or more movable component having an engaging member for cooperation with a cargo container;

the movable components of the container support arms being movable such that:

a cargo container engaged by the engaging members is movable between at least two positions with respect to the sub-frames,

in the first position, the container being located beyond the space between the two sub- frames and, in the second position, the container being located at least partially between the two sub-frames, and

the cargo container being rotatable by the apparatus to discharge its contents. The drive means for rotationally driving the rotating assembly may include one or more motor and gear means, which may conveniently be incorporated in or supported by at least one of the sub-frames.

Preferably, the container support arms are rotatable through (and even beyond) 360°. That is, they can rotate continuously full circle (and beyond). Once they have rotated full circle, rotation can still continue in the same direction— although possible, it is unnecessary for the direction of rotation to be reversed at that (or any other) point.

A locking means may be provided, that allows the container support arms to be locked in a preferred position.

Mechanical or electrical stops may also be provided, to ensure that the container support arms do not rotate beyond a pre-determined position.

The apparatus may, for example, be suspended from or mounted on a hoisting device, such as a crane, forklift or reach stacker.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain me advantages and principles of the invention. In the drawings:

Figure 1 is a front view of container handling apparatus according to a first embodiment of the present invention, which enables a container to be pivoted around its longitudinal axis to tip out the contents therefrom, with the container shown in a raised position such that the tipping system is located to either side of the container;

Figure 2 is a front view of the container handling apparatus of Figure 1, with the container shown in a lowered position such that the tipping system is located above the sides of the container;

Figure 3 is a front view of the container handling apparatus of Figure 1, where the tipping system has rotated the container through 45 degrees;

Figure 4 is a front view of the container handling apparatus as in Figure 3, but where the tipping system has rotated the container through 90 degrees; Figure 5 is a schematic diagram illustrating a side view of the container handling apparatus of Figure 1, with various components of the frame removed so as to more clearly illustrate how the container (shown here in a raised position) is held by the engaging member of a container support arm of the container handling apparatus; and

Figure 6 is another schematic diagram illustrating a a side view of the container handling apparatus of Figure 1, cut away to show how the container is held.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Dimensions of certain of the parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or illustration.

Turning now to the drawings, Figure 1 depicts container handling apparatus 10 as per the present invention, which is adapted to handle a container 12 of bulk material 14. In this embodiment, the container handling apparatus is suspended from a crane 16, which enables the container handling apparatus (and the container being held by that apparatus) to be re-positioned as required. The crane 16 is operable by cables 18 and has one or more twist-lock adapter 20 for engaging the longitudinal support member 22 of the apparatus 10. It is to be understood that there would be various other structural elements that are part of the assembly. However, these are well-known in the art and, for that reason, it is not proposed to recite them individually in this specification.

The support member 22 extends longitudinally and supports two sub-frames 24, which are spaced apart from each other, and may conveniently be located at (or proximal to) either end of support member 22. Preferably, the drive system whereby a container is rotated will comprise at least one motor 26 and gearbox 28, making up a rotating coupling 30, which may be located within (or associated with) at least one of the sub-frames 24. The motor and the gearbox drive a shaft 32, the shaft being linked by means of a boss 33 to a container support arm 34 having an end-piece 36 that engages the container, 12 through the well-known twist-lock system 38. Depending on the engineering configuration, a motor 26 and gearbox 28 may be located in each of the sub- frames 24, or in one sub-frame only. The gear box(es) 28 may, for example, be off- drive or bevel-drive gearbox(es), which are electronically controlled.

The motor and the gearbox rotate the shaft 32 and, given that the container is connected to the shaft via the container support arm 34, cause the container to rotate (see Figures 3 and 4), .thereby emptying the contents of the container.

Preferably, the rotating coupling 30 will allow the container support arms to be rotated through and beyond 360°. That is, they will be able to rotate continuously full circle and beyond. This can be accomplished by incorporating electrical slip rings in the coupling (in place of wiring, which would restrict rotation). Alternatively, a slew ring, ball bearing race, chain-and- sprocket system or other means may be utilised to enable this continuous rotation.

This continuous 360° rotation is a major advantage of the present system. In most prior art systems, a rotation of 170° at most is all that can be achieved.

The rotating coupling 30 can, for example, be hydraulic or electrical.

In an hydraulic coupling, 360° continuous rotation is achieved by using an hydraulic rotating coupling to allow oil to pass through the central rotating shaft 32 and to the twist-lock boxes 38 to facilitate operation of the twist-lock system.

In an electrical coupling, 360° continuous rotation is achieved by using an electrical rotating coupling to allow electric current to pass through the central rotating shaft 32 and for an electrical signal to operate the twist-lock boxes 38.

One or more safety brake can be provided. For example, one or more brake assembly (preferably, two "off - fail to safety" brake assemblies) may be incorporated to provide positive braking to either side of the container in the event of any type of failure, whether electrical, hydraulic or another type of failure. The safety braking system may, for example, form part of the gearbox(es).

Electronic proximity sensors may be used to keep track of the rotation of the container support arms 34 and/or the container 12 being handled by the apparatus.

The sub-frames 24, located on either side of the container handling apparatus 10, occupy an appreciable amount of lateral space, and this could be a problem when the apparatus is picking up a container from (for example) a group of containers that are packed tightly in a horizontal plane. Such a configuration is therefore not appropriate when a container is to be picked up from a group or line of containers which are arranged very close side-by-side. This problem may, for example, be at least partially alleviated by locating the pivotal attachment point (e.g. shaft 32) of the container support arms 34 at or proximal to the lower ends of their respective sub-frames 24.

To further alleviate this problem, the container handling apparatus 10 includes movable components (e.g. extendible members 40 which form sub-arms of the container support arms 34), to which the end-pieces 36 are attached., The extendible members 40 are, for example, slidingly attached to the container support arms 34 so that they cah be moved from a first position within the perimeter of those arms to a second position where they extend beyond the perimeter of those arms. There may, for example, be two extendible members per container support arm, and these extendible members are preferably metal rods. The sliding attachment can be provided by means of a roller or ball mechanism 35 on a track or slide system ^' on the container support arms, along which the extendible members can slide. In that way, and as shown best in Figure 2, they enable the end-pieces 36 of the container handling apparatus to be extended beyond the sub-frames 24 and readily engage the container by means of a twist-lock system 38.

This allows the extendible members 40 to be lowered downwards below the lowest point of the sub-frames so that they can engage (by means of the twist-lock system 38) with the container 12, even when that container forms part of a close-packed group or line of containers. The extendible members 40 of the container support arms 34 are then moved upwards to raise the container.

Thus, where a container that is effectively enclosed by other containers needs to be engaged, the crane operator simply adjusts the whole container-handling assembly until the sub- frames 24 are above the upper level of the container, whilst ensuring that the twist-locks 38 are still able to engage the container.

The twist-locks 38 of the end-pieces 36 of the container handling apparatus engage the top rails of the container. By increasing the strength of those top rails, the container effectively forms a "chassis" and adds to the strength of the container handling apparatus. This allows for the container handling apparatus to be lighter in construction without compromising strength or load carrying capacity.

When engagement has occurred, the container handling apparatus is operated to cause the container to be lifted vertically to a predetermined height or point and, when there is sufficient room, operates so that the extendible members 40 move to position the container at least partially within the space between the sub-frames 24.

When an operable position has been reached— that is, one where the container is at an appropriate level to be rotated, and is positioned appropriately (e.g. above a ship's hold, into which the contents of the container are to be discharged), the apparatus is locked in position enabling the operator to pivot the container and empty its contents. This is illustrated in Figures 3 and 4 (where the tipping system has rotated the container through 45 degrees and 90 degrees respectively).

The way in which a container is engaged by the container handling apparatus of the present invention is further illustrated in Figures 5 and 6.

Fail-safe measures, such as safety brakes and shaft locking systems, are preferably included in the system to provide positive braking to the rotation of the container 12 in the event of any type of failure. Also, devices such as proximity sensors or encoders may be incorporated, to keep track of the rotation of the container support arms 34 and/or the container 12 that is being handled.

For example, an encoder is preferably included in the system to keep track of the rotation of each of the container support arms 34 and ensure synchronisation of rotation of the container support arms at either end of the container being handled. The encoder may be capable of subdividing the 360° rotation cycle into up to 3000 sections (or even more), and track rotation through each of these sections.

Throughout this specification, except where the context requires otherwise due to express language or necessary implication, the word "comprising" (or variants such as "comprise" or "comprises") is used in the sense of "including"; i.e. the features specified may be associated with further features (whether or not specifically mentioned) in various embodiments of the invention. While specific embodiments of the invention have been described, it will be clear that variations of the details of the constructions which have been specifically illustrated and described may be made without departing from the principles and scope of the invention.

For example, while Figures 1 to 6 illustrate the apparatus being suspended from a crane, and with the sub-frames 24 depending downwardly from the support frame 22, in other embodiments (e.g. when mounted on a forklift) the apparatus may, for example, be rotated through 90 degrees so as to be effectively lying on its side (when compared to the embodiment of Figures 1 to 6), and references to raising and lowering of the container or of various components of the apparatus should in such instances be re-interpreted to include the equivalent movement in a different plane e.g. horizontal, rather than vertical, movement).