A device for picking up and depositing loads, for example loaded pallets

Abstract

The invention relates to a device for picking up and depositing loads, for example loaded pallets, wherein the device comprises at least one load supporting element adapted to be inserted from aside of a load for picking up the load. The invention further relates to a truck, such as a lift truck or a pallet truck, comprising the device. The invention also relates to a method for picking up and depositing loads, for example loaded pallets, with the device.

Description

[0001] Title: A device for picking up and depositing loads, for example loaded pallets.

[0002] Description:

[0003] The invention relates to a device for picking up and depositing loads, for example loaded pallets, wherein the device comprises at least one load supporting element adapted to be inserted from aside of a load for picking up the load. The invention further relates to a truck, such as a lift truck or a pallet truck, comprising the device. The invention also relates to a method for picking up and depositing loads, for example loaded pallets, with the device.

[0004] WO 96 / 13457 discloses a device for picking up and depositing loads, such as loaded pallets, comprising a carrying body with at least one load supporting element of the type, that is adapted to be inserted from aside of a load. The device is mounted with its carrying body for up and down movement on a vertical guide track at the front side of a fork lift truck. In the carrying body guiding tracks are provided. The load supporting element is mounted to move along said tracks between a retracted position and an extended position to be inserted from aside of a load, such as a loaded pallet. A drawback of the known device is for example that a load or an object behind the load being picked up can be damaged by means of the at least one load supporting element in the extended position. Further, an outwardly protruding portion of the at least one load supporting element with respect to the load may also be disadvantageous during transport of the load and during depositing the load.

[0005] It is an object of the present invention to provide an improved device for picking up and depositing loads. Such as for example a device adapted for facilitating improved picking up and depositing loads with varying / different dimensions .

[0006] At least one of the above objects is achieved with a device as defined in claim 1. The device for picking up and depositing loads, for example loaded pallets, comprises at least one load supporting element adapted to be inserted from aside of a load for picking up the load, a controller, a measurement unit for measuring at least one dimension of the load and a dimension obtain-unit configured for obtaining preentered dimensions of the load. The measurement unit and the dimension obtain-unit are configured to communicate with the controller. The controller is configured for identifying a pick-up side of the load based on the at least one measured dimension of the load and the pre-entered dimensions of the load. The controller is further configured for determining a working length of the at least one load supporting element measured from the identified pick-up side, wherein the working length is equal to or smaller than one of the pre-set dimensions of the load extending in a direction of the working length.

[0007] The controller is configured to communicate with the measurement unit and the dimension obtain-unit, such that by means of the controller a measured dimension of the load, such as measured width, length and / or height of a load to be picked-up, can be compared with pre-set dimensions of the load to be picked, such as pre-set width, length and / or height of the respective load to be picked-up. By comparing the measured dimension(s) with the pre-set dimensions of the load to be picked-up a pickup side of the load can be identified by means of the controller. By means of the obtained pre-set dimensions, the controller is then able to determine a working length for the identified pick-up side, wherein the working length is equal to or smaller than one of the pre-set dimensions of the load extending in a direction of the working length. In this manner, insertion from one side can be performed for picking up the load, wherein it may be prevented that a portion of the load supporting element outwardly protrudes on an opposite side of the load. Without such a protruding portion of the load supporting element, another load or object positioned behind the load to be picked up by the load supporting element can no longer be damaged by means of the at least one load supporting element. The same advantage may also be achieved during transport or depositing of the load, in that the risk of damaging the surrounding by means of a protruding load supporting element portion opposite the pick-up side can be reduced. With respect to the at least one dimension to be measured by means of the measurement unit, the measurement unit may be configured to measure at least the width dimension of the load and / or the length dimension of the load. The device is further capable of handling situations in which the length dimension or the width dimension cannot be measured, for example if the total length of the load is partly blocked by other objects from the perspective of the measurement unit of the device, in that the controller is configured to identify the pick-up side of the load based on a single measured dimension and the pre-entered dimensions of the load. In one aspect, the measurement unit is configured for measuring dimensions of a side of a load. By means of the two measured dimensions of the side, i.e. height with width or length of the load, and the pre-entered dimensions of the load, the controller is configured to identify the pick-up side of the load.

[0008] The device of this disclosure is particularly suitable for picking up and depositing loads with varying / different dimensions. The device of this disclosure is particularly suitable for improved picking up and depositing loads with varying / different dimensions, in particular loads requiring different working lengths of the at least one load supporting element, for example for safety reasons. The device of this disclosure is adapted for facilitating improved picking up and depositing loads with varying / different dimensions. The device of this disclosure is in addition or alternatively particularly suitable for picking up and depositing loads with varying / different dimensions without damaging or with reduced risk of damaging other loads and / or objects opposite to the pick-up side.

[0009] In another aspect, the device further comprises a communication unit configured to communicate with the controller and to exchange the determined working length to an operator operating the device. The communication unit may be provided by a display for providing instructions such as steering / driving instructions for a lift truck to the operator. In such a manual mode of the device, damaged loads / objects by an outwardly protruding load supporting element portion can be prevented by communicating instructions to the operator by means of the communication unit, such as working length.

[0010] In addition, or alternatively, the device comprises an autonomous control system configured to communicate with the controller in an autonomous mode of the device for at least automatically picking up loads by using the working length determined by the controller. Hence, the device can be operated without operator in the autonomous mode for automatically picking up loads. The device may be configured to switch between an autonomous mode and a manual mode.

[0011] The at least one load supporting element may be adapted to adjust its length, for example telescopically. The at least one load supporting element, often identified as a fork, comprises an adaptable length for adjusting the working length of the at least one load supporting element depending on the dimension of the load extending substantially traversely to the pick-up side of the load. Adapting the length may be done by an operator of the device following instructions from the communication unit, for example by manual operation of an actuator of the at least one load supporting element to adjust its length. For example, the length of the at least one load supporting element to be used may be longer than the dimension of the load extending in the same direction. To avoid an outwardly protruding portion of the load supporting element on an opposite side of the load with respect to the pick-up side of the load, the length of the load supporting element and its corresponding working length can be adjusted in this case shortened to a retracted length, such that an outwardly protruding portion of the load supporting element is prevented. On the other hand, it also possible that the length of the at least one load supporting element to be used is too short to ensure a relatively safe and / or stable pick-up of the load. In this case, the length of the at least one load supporting element is adapted, i.e. increased to obtain the required extended working length, to guarantee a safe and / or stable pickup of the load. The length of the at least one load supporting element may be automatically adjusted by means of the controller for adjusting the working length of the at least one load supporting element. The controller may automatically adjust the working length by means of the autonomous control system controlling an actuator of the at least one load supporting element to automatically adjust its length. In this manner damage to the surroundings can be reduced or even excluded such that the costs of damaged loads in for example a warehouse can be reduced drastically. In addition, or alternatively, a relatively safe and / or stable pickup of loads can be guaranteed by adjusting the working length to a safe and / or stable working length, which also includes increasing the length of the at least one load supporting element.

[0012] The device may comprise two load supporting elements, for example two known fork-like load supporting elements, wherein the dimension obtain-unit is configured for obtaining predetermined distances between the two load supporting elements for each pickup side of the loads, wherein the controller is further configured for identifying an associated predetermined distance between the two load supporting element for the identified pick-up side and to compare the associated predetermined distance with an actual distance between the two load supporting elements for varying the actual distance, for example by means of a drive unit of the device. In this manner a stable and correct pickup of loads can be guaranteed. The communication unit is configured to exchange the associated predetermined distance and the actual distance for varying the actual distance. By means of the communication unit an operator is able to vary the actual distance to the associated predetermined distance, for example by operating a drive unit of the device. In the autonomous mode of the device the actual distance is automatically varied by means of the controller. The controller is for example controlling a drive unit of the device for varying the actual distance.

[0013] The device may comprises a detecting unit for detecting a distance between the at least one load supporting element and the load, wherein the detecting unit is configured to communicate with the controller.

[0014] These data regarding the distance obtained by the detecting unit may be used by the controller to communicate with the communication unit and / or the autonomous control system.

[0015] In a further aspect, the device is mounted or adapted to be mounted on a lift truck or a pallet truck. The device may be used either in retrofitting an existing lift truck or a pallet truck, or in a new lift truck or a pallet truck.

[0016] It is further an object of the present invention to provide an improved method for picking up and depositing loads. Such as for example an improved method for picking up and depositing loads with varying / different dimensions.

[0017] At least one of these objects is achieved with the included method claim. The method for picking up and depositing loads, for example loaded pallets, is performed by a controller and a device comprising at least one load supporting element adapted to be inserted from aside of a load for picking up the load, wherein the method comprises the following steps:

[0018] - measuring at least one dimension of the load;

[0019] - obtaining pre-entered dimensions of the load;

[0020] - identifying a pick-up side of the load based on the at least one measured dimension of the load and the pre-entered dimensions of the load,

[0021] - determining a working length of the at least one load supporting element measured from the identified pick-up side, wherein the working length is equal to or smaller than one of the pre-entered dimensions of the load extending in a direction of the working length.

[0022] In one aspect of the method, a length of the at least one load supporting element is automatically adjusted by means of the controller for adjusting the working length of the at least one load supporting element. For purposes of convenience and brevity, reference is made to the advantages of the above-described device with respect to the corresponding advantages of the method embodiments described above. The invention further relates to a controller configured to perform the above method steps. The invention also relates to a computer program product, comprising a computer readable storage medium storing instructions which, when executed on at least one controller, cause said at least one controller to carry out the above method steps.

[0023] The aspects described above as well as other aspects of the device, the truck and the method will be explained hereunder on the basis of an exemplary embodiment in combination with figures. The invention is not, however, limited to the exemplary embodiments described hereunder. Rather, a number of adaptations and modifications are possible, which also make use of the idea of the invention claimed in the claims and consequently fall within the scope of protection. In particular, the possibility is mentioned of combining the features / aspects that are only mentioned in the description and / or are shown in the figures, with the features of the claims in so far as compatible.

[0024] Brief description of the drawings:

[0025] Figure 1 shows in a diagrammatic manner a lift truck with a device for picking up and depositing loads and a load;

[0026] Figure 2 shows a flow chart of a method of this disclosure for picking up and depositing loads, for example loaded pallets.

[0027] Detailed description of the drawings:

[0028] Figure 1 shows a device 1 for picking up and depositing loads 15, such as loaded pallets. In the embodiment shown, the device 1 is mounted on a lift truck 10, in particular the device 1 is provided on a vertical guide track 2 at the front side of the truck 10. By means of the vertical guide track 2 the device 1 with or without the load 15 can be vertically displaced. By means of the truck 10, the device 1 with or without the load 15 can be moved between locations for example in a warehouse such as a pickup location and a deposit location.

[0029] The device 1 comprises at least one load supporting element 3 adapted to be inserted under a load portion 15’ from aside of a load 15 for picking up the load 15, a controller 5, a measurement unit 7, for example a camera or for example comprising a camera, for measuring at least one dimension in the x, y, and / or z direction of the load 15 and a dimension obtain-unit 9, 109 configured for obtaining pre-entered dimensions in the x, y, and / or z direction of the load 15. The measurement unit 7 and the dimension obtain-unit 9, 109 are configured to communicate with the controller 5 which is configured for identifying a pick-up side P of the load 15 based on the at least one measured dimension of the load and the pre-entered dimensions of the load, wherein the controller 5 is further configured for determining a working / insertion length W of the at least one load supporting element 3 measured from the identified pick-up side, wherein the insertion length / insertion W is equal to or smaller than one dimension y’ of the pre-entered dimensions of the load extending in a direction of the working / insertion length W.

[0030] By means of the device, insertion under a load portion 15’ on a pallet 16 from one side can be performed for picking up the load 15, wherein it can be prevented that a portion of the load supporting element 3 protrudes on an opposite side of the load. Without such a protruding portion of the load supporting element, another load or object (identified by dotted line 25) positioned behind the load to be picked up by the load supporting element 3 can no longer be damaged by means of the protruding portion of the at least one load supporting element 3. The same advantage is also achieved during transport or depositing of the load, in that the risk of damaging the surrounding 25 by means of a protruding load supporting element portion opposite the pick-up side P can be reduced.

[0031] The device 1 of this disclosure is particularly suitable for picking up and depositing loads with varying / different dimensions, in particular loads 15 requiring different insertion lengths. In addition, without the risk or with reduced risk of damaging other loads and / or objects opposite to the pick-up side. In the embodiment shown the pallet 16 provides the dimension y’ of the load 15, but it is also possible that the maximum dimension of the load 15 extending in the y-direction is not provided by the pallet, but by the load portion.

[0032] As shown in figure 1 , the measurement unit 7 is configured for measuring the two dimensions of a side of a load extending in the x and z direction.

[0033] By identifying the pick-up side by means of the controller 5 the dimension of the z direction, i.e. the (pre-entered) height of the load, is known, such that it is possible to determine the volume of the load 15. It is also possible to use the height of the load measured by the measurement unit 7 to determine the volume of the load 15.

[0034] The device 1 further comprises a communication unit 11 configured to communicate with the controller 5 and to exchange the determined insertion length y’ to an operator operating the device. In the embodiment shown the communication unit 11 comprises a display.

[0035] The device 1 also comprises an autonomous control system 13 configured to communicate with the controller 5 in an autonomous mode of the device 1 for at least automatically picking up loads 15 from the pick-up side P with the insertion length y’ determined by the controller 5.

[0036] The at least one load supporting element 3 is adapted to adjust its length L, for example telescopically by means of an actuator (not shown). The length L can be adjusted by an operator based on instructions provided by the communication unit 1 communicating with the controller 5. The length L of the at least one load supporting element 3 may be automatically adjustable by means of the controller 5 for adjusting the insertion length W of the at least one load supporting element 3. To avoid a protruding portion of the load supporting element 3 on an opposite side of the load 15 with respect to the pick-up side P of the load, the length L of the load supporting element and the insertion length W can be adjusted, in particular shortened, such that a protruding portion of the load supporting element 3 is prevented. On the other hand, it also possible that the length L of the at least one load supporting element to be used for insertion is too short to ensure a relatively safe and / or stable pick-up of the load 15. In this case, the length L of the at least one load supporting element 3 is adapted, i.e. increased, to guarantee a safe and / or stable pickup of the load 15.

[0037] The device 1 shown in figure 1 comprises two dimension obtain-units 9; 109, i.e. a first dimension obtain-units provided by a scanner 109 configured for scanning a scannable item 19, for example a label or RFID-tag, associated or attached on the load 15 to obtain pre-entered dimensions of the load 15 and a second dimension obtain-unit provided by the antenna shown in figure 1 which is configured to communicate with an external database 21 to obtain pre-entered dimensions of the load 15. The external database 21 may comprises additional information-items, for example a location of the load to be picked-up, which can be displayed on the display of the communication unit 11 or used in an autonomous driving mode of the lift truck 10 or in an autonomous mode of the device 1.

[0038] Instead of two dimension obtain-units 9; 109, it is also possible to provide the device (not shown) of this disclosure with only one of two dimension obtain-units 9; 109.

[0039] The device 1 further comprises a detecting unit 23 which is configured to communicate with the controller 5. The detecting unit 23 is further configured for detecting or determining a distance Q between the at least one load supporting element 3 and the load 15, in particular the distance E between a first end of the at least one load supporting element 3 facing away from the load 15 and the load 15. The distance E is a standard corrected distance derived from distance Q, i.e. the start point for distance E has a fixed horizontal difference with the start point of Q provided by the detecting unit 23. Instead of detecting unit 23, it is also possible to detect distance E by means the measurement unit 7. Hence, instead of using two units 7, 23 in the device 1 , it is also possible to use only one unit, such as only the measurement unit 7 which may be for example a camera using software. It is also possible to detect / determine the length L of the at least one load supporting element by means of one of the units 7; 23. Knowing the length L and knowing the distance E provides an insertion distance (not shown in figure 1) of the at least one load supporting element extending in the direction of the insertion length measured from the pick-up side P inside the load 15, i.e. in the direction y (see indicated directions x,y,z in Fig. 1) in the embodiment shown in figure 1. Based on the distance E, the truck 10 can be manually driven by means of the controller 5 and the communication unit 11 and / or automatically driven by means of the controller 5 and the autonomous control system 13 in the y- direction and / or the length L of the load supporting element 3 is adjusted in the y- direction.

[0040] The two dimension obtain-units 9; 109, the measurement unit 7, the communication unit 11 and the detecting unit 23 are part of the device 1 , although arranged on the truck 10 in the embodiment shown in Fig. 1. It is also possible to arrange these components on the device of this disclosure. The positions in figure 1 of the components 5; 7, 9; 109; 23 of the device 1 are shown for illustrative purposes only and the actual positions of these components may differ in the device 1 . As shown in figure 2, the invention also relates to a method for picking up and depositing loads, for example loaded pallets, with a device 1 comprising at least one load supporting element 3 adapted to be inserted under a load portion 15’ of a load 15 for picking up the load. The method is performed by a controller 5, wherein the method comprises the following steps:

[0041] - measuring at least one dimension of the load (I);

[0042] - obtaining pre-entered dimensions of the load (II);

[0043] - identifying a pick-up side of the load (III) based on the at least one measured dimension of the load and the pre-entered dimensions of the load,

[0044] - determining an insertion length W (IV) of the at least one load supporting element measured from the identified pick-up side, wherein the insertion length W is equal to or smaller than one of the pre-entered dimensions of the load 15 extending in a direction of the insertion length.

[0045] In one aspect of the method, a length L of the at least one load supporting element 3 is automatically adjusted by means of the controller 5 (V) for adjusting the insertion length W of the at least one load supporting element 3. This step (V) is optional and therefore shown in a box with a dotted line. Alternatively, step (V) can be performed by an operator operating the device 1 from the cabine.

[0046] The device may comprise two load supporting elements, wherein the method may comprise the following additional step: obtaining predetermined distances between the two load supporting elements for each pickup side of the loads, wherein an associated predetermined distance between the two load supporting element is identified for the identified pick-up side and the associated predetermined distance is compared with an actual distance between the two load supporting elements for varying the actual distance. The actual distance may be automatically varied by means of the controller.

[0047] The insertion length W of the at least one load supporting element 3 under the load portion 15’ covers a substantial portion of the length L of the at least one load supporting element, i.e., the working / insertion length W of the at least one load supporting element is equal to or smaller than the length L of the at least one load supporting element, in particular the working / insertion length W covers between 50- 100% of the length L of the supporting element 3. In this manner, a safe and / or stable pickup of the load 15 can be guaranteed. The device 1 comprises a frame 4 for mounting the device on a lift truck 10 or a pallet truck (not shown). Each of the two L-shaped load supporting elements (only one is shown in figure 1) comprises an attachment portion 3a attached to the frame 4 and a fork portion 3b extending traversely to the frame 4 and the attachment portion 3a. For safety reasons and / or stability reasons, it may be required to position the load 15 to be picked up by means of the at least one load supporting element close to or even in contact with the frame 4 and / or the attachment portion 3a. The dimension obtain-unit 9; 109 may be configured for obtaining predetermined distances between the two load supporting elements 3b for each pickup side of the loads, wherein an associated predetermined distance between the two load supporting element is identified for the identified pick-up side and the associated predetermined distance is compared with an actual distance between the two load supporting elements 3b for varying the actual distance. The actual distance may automatically be varied by means of the controller 5.

[0048] Further, it is possible that the length of the at least one load supporting element 3 is fixed, i.e. unadjustable. The insertion length W is then a portion of the total fixed length L of the at least one load supporting element 3. The working / insertion length W of the at least one load supporting element is equal to or smaller than the length L of the at least one load supporting element. For a safe and / or stable pickup of the load 15, the working / insertion length W covers between 50-100% of the length L of the supporting element 3.

[0049] A device for picking up and depositing loads, for example loaded pallets, wherein the device comprises two load supporting elements 3b adapted to be inserted from aside of a load 15 for picking up the load, a controller 5, a measurement unit 7 for measuring at least one dimension of the load and a dimension obtain-unit 9; 109 configured for obtaining pre-entered dimensions of the load including predetermined distances between the two load supporting elements for each pickup side of the loads, wherein the measurement unit and the dimension obtain-unit are configured to communicate with the controller which is configured for identifying a pick-up side of the load and an associated predetermined distance between the two load supporting elements based on the at least one measured dimension of the load and the preentered dimensions of the load, wherein the controller is further configured to compare the associated predetermined distance with an actual distance between the two load supporting elements for varying the actual distance. The device may further comprises a communication unit configured to communicate with the controller and to exchange the associated predetermined distance to an operator, preferably the communication unit comprises a display. By means of the communication unit the operator may be able to operate a drive unit of the device for varying the actual distance if required and / or may be able to check if the actual distance corresponds to the associated predetermined distance. The device may, in addition or alternatively, comprise an autonomous control system configured to communicate with the controller in an autonomous mode of the device for automatically varying the actual distance to the associated predetermined distance for example by means of a drive unit of the device.

[0050] The device discussed in this paragraph is compatible with other features, see also attached claims, of this disclosure.

Claims

CLAIMS1. A device for picking up and depositing loads, for example loaded pallets, wherein the device comprises at least one load supporting element adapted to be inserted from aside of a load for picking up the load, a controller, a measurement unit for measuring at least one dimension of the load and a dimension obtain-unit configured for obtaining pre-entered dimensions of the load, wherein the measurement unit and the dimension obtain-unit are configured to communicate with the controller which is configured for identifying a pick-up side of the load based on the at least one measured dimension of the load and the pre-entered dimensions of the load, wherein the controller is further configured for determining a working length of the at least one load supporting element measured from the identified pick-up side, wherein the working length is equal to or smaller than one of the pre-entered dimensions of the load extending in a direction of the working length.

2. The device according to claim 1 , wherein the measurement unit is configured for measuring the dimensions of a side of a load.

3. The device according to claim 1 or 2, wherein the device further comprises a communication unit configured to communicate with the controller and to exchange the determined working length to an operator operating the device, preferably the communication unit comprises a display.

4. The device according to any of the preceding claims, wherein the device comprises an autonomous control system configured to communicate with the controller in an autonomous mode of the device for at least automatically picking up loads by using the working length determined by the controller.

5. The device according to any of the preceding claims, wherein the at least one load supporting element is adapted to adjust its length, for example telescopically.

6. The device according to claim 5, wherein the length of the at least one load supporting element is automatically adjustable by means of the controller for adjusting the working length of the at least one load supporting element.

7. The device according to any of the preceding claims, wherein the dimension obtain-unit comprises a scanner configured for scanning a scannable item, for example a label or RFID-tag, associated or attached on the load to obtain pre-entered dimensions of the load.

8. The device according to any of the preceding claims, wherein the dimension obtain-unit is configured to communicate with an external database to obtain preentered dimensions of the load.

9. The device according to any of the preceding claims 1-4, 7 or 8, wherein the length of the at least one load supporting element is fixed.

10. The device according to any of the preceding claims, wherein the device comprises a detecting unit for detecting a distance between the at least one load supporting element and the load, wherein the detecting unit is configured to communicate with the controller.

11. The device according to any preceding claim, wherein the device is mounted or adapted to be mounted on a lift truck or a pallet truck.

12. The device according to any preceding claim, wherein the device comprises two load supporting elements, wherein the dimension obtain-unit is configured for obtaining predetermined distances between the two load supporting elements for each pickup side of the loads, wherein the controller is further configured for identifying an associated predetermined distance between the two load supporting element for the identified pick-up side and to compare the associated predetermined distance with an actual distance between the two load supporting elements for varying the actual distance, for example by means of a drive unit of the device.

13. The device according to claim 3 and 12, wherein the communication unit is configured to exchange the associated predetermined distance and the actual distance for varying the actual distance.

14. The device according to claim 4 and 12 or claim 4 and 13, wherein in the autonomous mode of the device the actual distance is automatically varied by means of the controller.

15. A truck, such as a lift truck or a pallet truck, comprising the device according to any preceding claim.

16. The truck according to claim 15, wherein the device is provided on a vertical guide track at the front side of the truck.

17. A method for picking up and depositing loads, for example loaded pallets, with a device comprising at least one load supporting element adapted to be inserted from aside of a load for picking up the load and the method is performed by a controller, wherein the method comprises the following steps:- measuring at least one dimension of the load;- obtaining pre-entered dimensions of the load;- identifying a pick-up side of the load based on the at least one measured dimension of the load and the pre-entered dimensions of the load,- determining a working length of the at least one load supporting element measured from the identified pick-up side, wherein the working length is equal to or smaller than one of the pre-entered dimensions of the load extending in a direction of the working length.

18. The method according to claim 17, wherein a length of the at least one load supporting element is automatically adjusted by means of the controller for adjusting the working length of the at least one load supporting element.

19. The method according to claim 17 or 18, wherein the device comprises two load supporting elements, wherein the method comprises the following step:obtaining predetermined distances between the two load supporting elements for each pickup side of the loads, wherein an associated predetermined distance between the two load supporting element is identified for the identified pick-up side and the associated predetermined distance is compared with an actual distance between the two load supporting elements for varying the actual distance.

20. The method according to claim 19, wherein the actual distance is automatically varied by means of the controller.

21. A controller configured to perform the method according to any of the preceding claims 17-20.

22. A computer program product, comprising a computer readable storage medium storing instructions which, when executed on at least one controller, cause said at least one controller to carry out the method according to any of the preceding claims 17-20.

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