The invention relates to lifting devices for cargo handling. More specifically, the invention relates to spreaders suitable for grabbing and lifting bulk cargo.

Bulk cargo may not be protected by a shipping container, therefore it is vulnerable to handling damages and errors made during cargo handling. One example of such bulk cargo is plank wood. At the sawmill the sawed plank wood is arranged into precise piles and the piles are bound by tie-down straps. As the pile of plank wood is processed and transported, a single plank wood may slightly move around in the pile - at least few millimetres. After several steps of handling the pile of plank wood may have lost its original form significantly. Handling of cargo at a port yard must be quick and precise. Any additional delays and disturbances result in extra costs by having ships idle in the berth, and even more so if the loading/unloading is for some reason delayed, thus making the ship late in her route schedule. As the pile of wood bound with tie down straps gradually loses its form, it becomes more difficult to handle. In one scenario the tie-down straps snap loose due to the forces from the deforming pile. Yet the deformed piles must be lifted, as fast as possible, into the ship’s cargo hold - or out of the cargo hold at the destination.

The cargo hold shape may not be optimal for receiving several piles of plank wood. The piles of plank wood may be arranged on top of each other at odd angles. This causes even more problems to the form of the piles. Lifting the piles becomes increasingly difficult as the space between the piles is not even. The risk of snapping the tie-down strap increases and causes hazard for the personnel handling the cargo.

Often bulk cargo such as plank wood has been processed manually, as the shapes and sizes of the piles of plank wood may have deformed during processing. Manual handling or manual operation of lifting devices has minimized the damages to the plank wood. The handling of bulk goods, such as plank wood has traditionally required a lot of human labour. The human labour is still prone to errors and unnecessary delays.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure. A spreader for lifting a load is disclosed. The load may be operated and transported at a port yard area, wherein the load is bulk goods such as plank wood. The load is not carried in a shipping container or an intermodal container, being vulnerable to damages during the transport. The load size may be similar to that of a container. The spreader may support the load simultaneously from three sides; from two opposite sides and below. The sides are supported by a first vertical portion and a second vertical portion that are opposite to each other, positioned on the long sides of the load. The vertical portions are flat enabling to fit them, as one example, between stacked piles of plank wood. Sometimes the stacked piles may have only small gaps between them, as the piles are bound by tie-down straps that allow some movements to the plank wood. The piles may not always retain their original form in the stack.

Additionally, a supporting element extends from the lower portion of the vertical portion to support the load from below. The supporting element is in one example a link chain that folds only to one direction. The vertical portion accommodates the vertical portion of the link chain when the link chain is fully retracted. The link chain extends horizontally from the vertical portion, wherein the folding portion of the link chain is in the vertical portion. When the link chain is fully expanded, a portion of the link chain remains in the vertical portion that provides support for the vertical position of the link chain. The present embodiments are suitable for use in the handling of bulk cargo, such as plank wood, e.g. when picking up a pile of plank wood and/or when stacking piles. The horizontal supporting element such as the link chain structure is flat, which enables it to enter into tight passages between stacked piles of plank wood. The friction may be reduced by having rollers extending above the link chain, thereby mitigating the risk for any damage that could occur by inserting the supporting element into tight passages.

The spreader assembly maintains the bulk cargo in shape during lifting. The handling of bulk cargo such as plank wood may be automatized as the spreader handles the plank wood gently and the stacks remain in proper shape. The overall loading/unloading times of a berthing ship may be reduced. The automatized process improves also the safety of harbour personnel, as the immediate presence of a human operator is not required.

Many of the attendant features will be more readily appreciated as they become better understood by reference to the following detailed description considered in connection with the accompanying drawings. The embodiments described below are not limited to implementations which solve any or all the disadvantages of cargo lifting devices. BRIEF DESCRIPTION OF THE DRAWINGS

The present description will be better understood from the following detailed description read in light of the accompanying drawings, wherein

FIG. 1 illustrates schematically one exemplary embodiment of a spreader;

FIG. 2a illustrates schematically one exemplary embodiment of a first supporting element in a fully retracted position; FIG. 2b illustrates schematically one exemplary embodiment of the first supporting element in a partially extended position;

FIG. 3 illustrates schematically a partial axonometric projection of one exemplary embodiment of the first vertical portion; FIG. 4 illustrates schematically a front view of one exemplary embodiment of the first vertical portion;

FIG. 5a illustrates schematically a partial side view illustrating a first step of one exemplary embodiment of the link chain as it travels through the lower portion of the first vertical portion; FIG. 5b illustrates schematically a partial side view illustrating a second step of one exemplary embodiment of the link chain as it travels through the lower portion of the first vertical portion;

FIG. 6a illustrates schematically a first axonometric projection of one exemplary embodiment on a locking assembly for the link chain; FIG. 6b illustrates schematically a second axonometric projection of one exemplary embodiment on the locking assembly for the link chain;

FIG. 7 illustrates schematically one exemplary embodiment of the vertical link chain guide;

FIG. 8 is a partial view illustrating schematically one example of deformed stacked piles of plank wood; and

FIG. 9 illustrates schematically one exemplary embodiment for lifting simultaneously multiple piles of plank wood.

Like reference numerals are used to designate like parts in the accompanying drawings. DETAILED DESCRIPTION

The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utilized. However, the same or equivalent functions and sequences may be accomplished by different examples.

Although the present examples are described and illustrated herein as being implemented as a ship-to-shore crane attachment, they are provided as an example and not a limitation. As those skilled in the art will appreciate, the present examples are suitable for application in a variety of different types of cargo lifting devices.

A spreader according to the present example is a device used for lifting a load, more particularly unitized cargo. The unitized cargo may be bulk cargo, such as a plank wood bound by tie-down straps. FIG. 8 illustrates schematically one example of stacked piles 81 , 82, 83, 84 of plank wood. The illustration is drawn from a real example photographed at a port yard area. In this example the pile 83 is covered with tarpaulin. Sometimes the pile of plank wood loses its form as the tie-down straps allows some free play to the pile. The deformation progresses each time when the pile of wood is lifted or handled. When the piles are stacked, the gaps between the piles 81 , 82, 83, 84 may be less than perfect. In the solutions according to prior art the piles have been lifted from below by a front loader or a fork truck or from above using the tie-down straps. The forks may damage the plank wood when entering into the stack. Plank wood is one example of vulnerable bulk cargo, where careless handling of the cargo may reduce its value.

FIG. 1 illustrates schematically one exemplary embodiment of the spreader according to the invention. A top portion 10 comprises means 14 for connecting to a crane. The crane may be a ship-to-shore crane, a straddle carrier, a stacking crane or any other crane suitable for lifting maritime cargo. The top portion 10 is positioned over the load during lifting. A first vertical portion 11 is connected to the top portion 10, configured to support the load from a first side. A second vertical portion 12 is configured to support the load from a second side. The second vertical portion is connected to the top portion 10 parallel to the first vertical portion 11. The arrangement is configured to receive the load between the parallel first vertical portion 11 and the second vertical portion 12. The load may comprise a long side and a short side, wherein the first vertical portion 11 and the second vertical portion 12 support the load from its opposite long sides. In one embodiment the spreader is configured to lift simultaneously two piles of plank wood or multiple piles or plank wood from the stack.

A first supporting element is configured to retract into the first vertical portion 11 and extend horizontally from a lower portion 16 of the first vertical portion 11 to support the load from below. In one exemplary embodiment the first supporting element 20 extends and retracts telescopically. In one exemplary embodiment the first supporting element 11 comprises a solid and swivelling structure configured to rotate along a vertical axis defined inside the first vertical portion 11 ; between a first position under the first vertical portion 11 and parallel to the first vertical portion 11 ; and a second position 12 transversely to the first vertical portion 11 under the load.

In one embodiment the first vertical portion 11 is movable in relation to the top portion 10. The top portion 10 comprises a first top actuator 13 for moving the first vertical portion 11 horizontally to change the distance between the first vertical portion 11 and the second vertical portion 12. The first vertical portion 11 may be moved laterally in order to fit into the gap between the stacks. In one embodiment the angle of the first vertical portion 11 in relation to the top portion 10 is adjustable. The adjustment may be fixed or controllable during the lifting process. The first top actuator 13 is in one embodiment a hydraulic cylinder.

The first top actuator 13 is in one embodiment an electric motor.

In one embodiment the first top actuator 13 is configured to move simultaneously both the first vertical portion 11 and the second vertical portion 12. In one embodiment the first top actuator 13 is configured to move alternatively either the first vertical portion 11 or the second vertical portion 12.

In one embodiment the second vertical portion 12 is movable in relation to the top portion 10. The top portion 10 comprises a second top actuator 15 for moving the second vertical portion 12 horizontally to change the distance between the first vertical portion 11 and the second vertical portion 12. The second vertical portion 12 may be moved laterally in order to fit into the gap between the stacks. In one embodiment the angle of the second vertical portion 12 in relation to the top portion 10 is adjustable. The adjustment may be fixed or controllable during the lifting process. The second top actuator 15 is in one embodiment a hydraulic cylinder. The second top actuator 15 is in one embodiment an electric motor.

FIG. 2a and FIG. 2b illustrate schematically one exemplary embodiment of the first supporting element. The first supporting element comprises a link chain 20 having multiple links hingedly interconnected by pivot shafts. In FIG. 2a the link chain 20 is in a fully retracted position. In FIG. 2b the link chain 20 is in a partially extended position. The link chain 20 is in one embodiment configured to travel inside first vertical portion 11 along the vertical link chain guide 22. The link chain 20 is configured to fold only to one direction. The extended link chain 20 is supported by the first vertical portion 11 , wherein the extended link chain 20 is in vertical position when supporting the load. In this example the link chain 20 folds only in the lower portion 16 of the first vertical portion 11. The lower portion 16 comprises an opening in the first vertical portion 11 and an arcuate link chain guide arranged below the link chain guide 22, configured to steer the link chain 20 between a vertical position and a horizontal position.

FIG. 3 illustrates an axonometric projection of the first vertical portion 11. FIG. 4 illustrates a front view of the first vertical portion 11. The first vertical portion 11 houses means for locking the link chain 20 in place and means for moving the link chain 20 along the link chain guide 22. A locking actuator 31 is configured to lock the link chain 20. The locking actuator 31 may be a hydraulic cylinder or an electric motor that operate a locking pin 60. The locking pin 60 operation is illustrated further in FIG. 6a and FIG. 6b. The means for moving the link chain 20 along the link chain guide 22 comprise a hydraulic cylinder 32 or an electric motor. The hydraulic cylinder 32 operates a piston that is connected to the link chain 20 to reciprocate the link chain 20 along the link chain guide 22. The hydraulic cylinders allow precise control to the link chain 20 movement. In one embodiment the electric motor is configured to rotate and move the link chain 20 via a gear. In one embodiment the link chain 20 forms a roll inside the first vertical portion 11. In one embodiment the link chain 20 forms a two-fold inside the first vertical portion 11. In one embodiment the link chain 20 folds between a horizontal position transversely to the first vertical portion 11 and a horizontal position along the first vertical portion 11.

FIG. 5a and FIG. 5b are partial side views illustrating steps of the link chain 20 as it travels through the lower portion 16 of the first vertical portion 11. The link chain 20 comprises two laterally spaced outer side pieces 53, held together by a first pivot shaft 51 extending between the outer side pieces 53 at a first end and a second pivot shaft 52 extending between the outer side pieces 53 at a second end. An inner piece 55 is connected between consecutive outer side pieces 53 by the first pivot shaft 51 and the second pivot shaft 52. The link chain 20 folds along the pivot shafts 51 , 52 only to one direction. In the present example the link chain 20 folds only upwards. The folding movement downwards is limited by blocks 50 that are positioned below the horizontal level defined by the pivot shafts 51 , 52 or, more particularly, the level defined by the rotational axes of the pivot shafts 51 , 52. The block 50 is connected to one link, wherein one link is defined by one set of outer side pieces 53 and the inner piece 55. In one embodiment the block 50 is connected to at least one outer side piece 53 of one link. In one embodiment the block 50 is connected to both one outer side pieces 53 of one link. In one embodiment the block 50 is connected to the inner side piece 55 of one link. In one embodiment the block 50 is connected below the outer side piece 53. Consecutive blocks 50 abut against each other when the link chain 20 is in straight position, preventing the link chain 20 from folding downwards. In the present example length of the single block 50 matches the length of one link. Consecutive blocks 50 move apart when folding the link chain 20 upwards. Directions such as up or down are used herein for illustrative purposes, as it is obvious that the directions apply to any of the link chain’s 20 orientation.

In one embodiment the block 50 is arranged to be a portion of the outer side pieces 53. In one embodiment consecutive outer side pieces 53 abut each other. Above the level defined by the rotational axes of the pivot shafts 51 , 52 the consecutive outer side pieces 53 have rounded abutting edges, allowing the link chain to fold upwards. Below the level defined by the rotational axes of the pivot shafts 51 , 52 the consecutive outer side pieces 53 have straight abutting edges, preventing the link chain 20 to fold downwards. In one embodiment the straight abutting edge of the outer side piece 53 is one example of the block 50.

In one embodiment the link chain 20 comprises a roller 55 around the first pivot shaft 51 and/or the second pivot shaft 52, said roller 55 having a diameter extending above the outer side pieces 53 and the inner piece 55 when the link is in horizontal position. The link chain 20 may have the rollers 50 on all pivot shafts 51 , 52 and on all links. In one embodiment the link chain 50 comprise rollers 50 only at some of the shafts 51 , 52. The rollers 50 extend visibly in the side view above the link chain 20, when the link chain is in horizontal position. The rollers 50 may roll freely along the shafts 51, 52. The rollers 50 reduce the friction of the link chain 20 when it enters the horizontal gap between the stacked piles of plank wood. The rollers 50 mitigate or prevent the damage that may incur by inserting the link chain 20 into narrow passages. In one example the rollers 50 extend visibly in the side view below the block 50, allowing the link chain 50 to travel along the rollers 50 on both its upper surface and lower surface when entering the narrow passages.

FIG. 6a and FIG. 6b are axonometric projections illustrating schematically a locking assembly of the link chain 20 as it travels through the lower portion 16 of the first vertical portion 11. The link chain 20 comprises locking slots 56 that are in the present example arranged in the block 50. In one embodiment the locking slots 56 are available only when the link chain is in straight position. In one embodiment the locking slots 56 are arranged as multiple teeth in the block 50.

In one embodiment the locking slots 56 are arranged to the outer side piece 53.

In one embodiment the first vertical portion 11 comprises a movable locking pin 60. The locking pin 60 enters selectively the locking slot 56, securing the link chain 20. FIG. 6a and FIG. 6b are illustrated without the link chain 20. The lower portion 16 of the first vertical portion 11 comprises a guide hole 61 configured to provide lateral position to the locking pin 60. The locking actuator 31 is configured to move the locking pin 61 between an open position and a locked position. In FIG. 6b the block 50 has just reached horizontal level, wherein the locking pin 60 may secure the link chain 20. In one embodiment the vertical hydraulic cylinder 32 operates a locking structure configured to secure the link chain 20.

FIG. 7 illustrates schematically one exemplary embodiment of the vertical link chain guide 22. The vertical link chain guide 22 may comprise a groove for allowing any accessories attached to the vertical hydraulic cylinder 32 to travel inside the vertical link chain guide 22.

The second vertical portion 12 may comprise similar structure as the first vertical portion 11, having the first support element and/or the link chain 20. The first vertical portion 11 and/or the second vertical 12 may comprise multiple first supporting elements, providing additional support for the load from below. In one embodiment each first support element is controllable individually; sometimes the bottom of the load is uneven and all first supporting element may not be fully extended. The control system of the spreader is on one embodiment configured to detect the force required to extend the first supporting element. The control system of the spreader may proceed to lifting only when at least predefined portion of the first supporting element has entered vertically below the load.

FIG. 9 illustrates schematically one exemplary embodiment for lifting simultaneously two piles of plank wood or multiple piles or plank wood from the stack. Between the first vertical portion 11 and the second vertical portion 12 is a third vertical portion 90 connected to the top portion 10. The third vertical portion is parallel to the first vertical portion 11 and the second vertical portion 12. In one embodiment the third vertical portion 90 is fixed to the top portion 10. In one embodiment the third vertical portion 90 is movable in relation to the top portion 10. When lifting the load having multiple parallel piles, the third vertical portion 90 is lowered between the piles. A first pile is supported from its first side by the first vertical portion 11 and from its second side by the third vertical portion 90. A second pile is supported from its first side by the third vertical portion 90 and from its second side by second vertical portion 11. The arrangement helps to maintain the shape of the first pile and the second pile during lifting. A spreader for lifting a load is disclosed, comprising a top portion configured to be connected to a crane and to be positioned over the load; a first vertical portion connected to the top portion, configured to support the load from a first side; and a second vertical portion, configured to support the load from a second side, connected to the top portion parallel to the first vertical portion.

The spreader comprises a first supporting element configured to retract into the first vertical portion and extend horizontally from a lower portion of the first vertical portion to support the load from below. In one embodiment, the first supporting element comprises a link chain having multiple links hingedly interconnected by pivot shafts; the links comprising blocks below the horizontal level defined by the pivot shafts, wherein consecutive blocks abut against each other when the link chain is in straight position, preventing the link chain from folding downwards; and consecutive blocks move apart when folding the link chain upwards. In one embodiment, a link in the link chain comprises two laterally spaced outer side pieces; at least one inner piece; a first pivot shaft extending between the outer side pieces at a first end; a second pivot shaft extending between the outer side pieces at a second end; a first end of the inner piece is connected to the outer side pieces by the second pivot shaft; a second end of the inner piece is connectable to the first pivot shaft of the next link; and the block is connected below the outer side piece, matching the length of one link. In one embodiment, the link in the link chain comprises a roller around the first pivot shaft and/or the second pivot shaft, said roller having a diameter extending above the outer side pieces and the inner piece when the link is in horizontal position. In one embodiment, the link in the link chain comprises a locking slot in the straight position; the first vertical portion comprises a movable locking pin configured to enter the locking slot for locking the movement of the first supporting element. In one embodiment, the first vertical portion comprises a locking actuator configured to move the locking pin between an open position and a locked position. In one embodiment, the first vertical portion comprises a vertical link chain guide, wherein the link chain is configured to travel along the vertical link chain guide; and the bottom portion of the vertical link chain guide comprises an arcuate link chain guide configured to fold the link chain between the vertical position and the horizontal position as the link chain travels along the link chain guide. In one embodiment, the spreader comprises a hydraulic cylinder configured to move the link chain along the vertical link chain guide. In one embodiment, the second vertical portion comprises a second supporting element according to the first support element in the first vertical portion as defined in the preceding claims. In one embodiment, the top portion comprises a first top actuator for moving the first vertical portion horizontally to change the distance between the first vertical portion and the second vertical portion. In one embodiment, the top portion comprises a first top actuator for moving the first vertical portion and the second vertical portion horizontally to change the distance between the first vertical portion and the second vertical portion. In one embodiment, the top portion comprises a second top actuator for moving the second vertical portion horizontally to change the distance between the first vertical portion and the second vertical portion. In one embodiment, the first vertical portion comprises multiple first supporting elements. In one embodiment, the second vertical portion comprises multiple second supporting elements. In one embodiment, the spreader comprises a third vertical portion connected to the top portion, parallel to the first vertical portion and the second vertical portion. In one embodiment, the load is plank wood bound by tie-down straps.

Alternatively, or in addition, the spreader control function can be performed, at least in part, by one or more hardware components or hardware logic components. The controls may be implemented on the crane. An example of the control system described hereinbefore is a computer-based device comprising one or more processors which may be microprocessors, controllers or any other suitable type of processors for processing computer-executable instructions to control the operation of the device in order to control one or more sensors, receive sensor data and utilize the sensor data. The control system may be positioned on the host system and connected to the apparatus. The computer-executable instructions may be provided using any computer- readable media that is accessible by a computer-based device. Computer- readable media may include, for example, computer storage media, such as memory and communications media. Computer storage media, such as memory, includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by a computing device. In contrast, communication media may embody computer-readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave, or other transport mechanism. As defined herein, computer storage media does not include communication media. Therefore, a computer storage medium should not be interpreted to be a propagating signal per se. Propagated signals may be present in a computer storage media, but propagated signals per se are not examples of computer storage media. Although the computer storage media is shown within the computing-based device, it will be appreciated that the storage may be distributed or located remotely and accessed via a network or other communication link, for example, by using a communication interface.

The apparatus or the device may comprise an input/output controller arranged to output display information to a display device which may be separate from or integral to the apparatus or device. The input/output controller is also arranged to receive and process input from one or more devices, such as a user input device (e.g. a mouse, keyboard, camera, microphone or other sensor). The spreader may comprise the controller or receive the commands from the controller arranged at the crane.

Any range or device value given herein may be extended or altered without losing the effect sought.

Although at least a portion of the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims.

It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to ‘an’ item refers to one or more of those items.

The term ‘comprising’ is used herein to mean including the elements identified, but that such elements do not comprise an exclusive list and an apparatus may contain additional elements.

It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this specification.