EP3176123B1 - Lifting device and method for power assistance when moving goods - Google Patents

Description

The present invention relates to a lifting device and a method provided for providing force support when moving an item.

U.S. 6,386,513 B1 discloses a lifting device comprising an end effector which is grasped by a human operator and applied to a load from above. The end effector is suspended by a line from a take-up reel, winch, or drum that is driven by an actuator to raise or lower the load. The end effector includes a force sensor that measures the vertical force that the operator applies to the end effector and provides a signal to a controller. The controller and actuator are designed so that a predetermined percentage of the force required to raise or lower the load is applied by the actuator, with the remaining force being provided by the operator. The load thus feels lighter to the operator, but the operator does not lose the feeling of being lifted against both the gravitational and inertial forces emanating from the load. The load is borne solely by the end effector.

While many of the processes involved in moving goods in logistics, in order picking activities, in airport baggage sorting systems and in mail sorting systems are largely automated, work is still done manually, especially at end points. In particular, loose loading and unloading of swap bodies, trailers or other large-volume transport units is often still done manually.

Due to the weight of the goods, manual loading and unloading represents a high level of physical strain, especially in the case of heavy goods such as luggage or mail. Each operator moves several tons a day, which leads to increased costs due to physical wear and tear. A special feature when loading containers with goods is that they are advantageously stacked with the highest possible density and stability. To avoid damage, it makes sense to place heavy goods near the floor and lighter goods in the upper area of the container. Manual loading and unloading is a very complex sequence of movements, which makes automation difficult.

State-of-the-art technology to relieve the operator are telescopic conveyors, which are operated manually via a control unit. The telescopic conveyors protrude sufficiently far into the container to be loaded or unloaded and can be swiveled horizontally and vertically in order to feed the goods to the operator. After an automatic transport into the container via the telescopic conveyor, the goods still have to be picked up and moved by hand.

WO2005110907A1 presents a suction hose lifting device and a method for moving a load with a suction hose lifter.

WO2006128405A1 discloses a lifting device which supports at least one hand which grips the object during manual displacement of objects.

Since parcel processing has become a focus of the logistics industry in recent years, a better solution to the situation described above has great potential, especially in mail sorting systems. Since mail and luggage are usually neither uniformly heavy nor uniformly large goods, this places great demands on the range of applications of a lifting device.

The existing telescopic conveyors usually have a low adjustment speed; in addition, the manual operation of the control unit means that an item has to be picked up several times, which slows down loading and unloading.

The use of the suction hose lifting device requires that the goods to be moved can be connected to the suction hose lifting device by exerting a negative pressure. If this is not possible, for example, due to the nature of the surface of the goods, the goods must be moved manually without any support from the suction hose lifting device. In the event of a malfunction, the goods can fall down during the movement, causing both the goods and the operator can be harmed. The suction hose lifting device must also be held manually by the operator while the goods are moving.

In the WO2006128405A1 The lifting device disclosed comprises a lifting element designed to receive an arm, the movement of the hand of this arm being supported. Although the weight of the goods is absorbed by the lifting device, it nevertheless initially loads the arm and / or hand of the operator, in particular when the goods are picked up.

The present invention is therefore based on the object of making possible an improved lifting device with a wide range of applications and simple operation.

The solution according to the invention provides a lifting device which is suitable for providing force support when moving a good, according to independent claim 1.

So that a weight acting on the at least one body part attached to the lifting aid is as low as possible, the lifting force support of the lifting aid can act directly on the suction gripping element. The lifting force support is as direct as possible without putting any strain on the body part.

In order to enable particularly simple handling and use through quick and uncomplicated reception of the at least one body part, as well as an uncomplicated and thus inexpensive implementation of the fastening device, the fastening device can be designed as a loop for receiving the body part. So that a suction gripping element is provided for each of the two arms and / or hands of an operator, the lifting device comprises at least two suction gripping elements. This enables intuitive handling of the lifting device, since it is based on a physiological sequence of movements. In addition, by using the two suction gripping elements, the force support can be provided redundantly when moving an item. In the event of a malfunction of one of the two suction gripping elements, the other suction gripping element is still available.

So that an optimal gripping position can be selected, i.e. the item can be gripped flexibly and thus particularly easily and intuitively with the suction gripping element and the direction in which the holding force is exerted is adapted to the respective item, the suction gripping element can be designed with the item from the side and / or from to grip from above and / or from below. The suction gripping element can thus grip an item almost as flexibly as a human operator.

At least one control element can be provided for activating and / or deactivating the lifting force assistance of the lifting aid and / or the holding force of the suction gripping element. The power assistance can thus be activated and / or deactivated in a simple manner with the operating element. This enables the lifting force support that can be exercised with the lifting aid and / or that with the suction gripping element exertable holding force only to be exerted if the operator deems it necessary.

So that the operating element is particularly easy to operate and the actuation of the operating element does not cause any severe impairment of the sequence of movements when using the lifting device, the at least one operating element can be arranged directly on the suction gripping element and / or the fastening device. Thus, the at least one operating element can also be operated without major inconvenience when the suction gripping element is attached to the at least one body part.

In order to enable flexible positioning of the lifting aid and thus to ensure that the lifting force support of the lifting aid is always optimally positioned and / or engages the goods, the lifting aid can be designed to be movable horizontally and / or vertically.

With regard to a method, the above-mentioned object is achieved by a method for moving an item according to independent claim 8.

In order to ensure a redundant and thus fail-safe exercise of the holding force on the good and thus prevent the good from falling, the holding force can be applied to the good with the suction gripping element and / or with the at least exercising a body part. If the holding force exerted by the suction gripping element fails, the holding force is exerted by the body part of the operator.

In order to ensure that the operator is relieved of stress when moving the goods, the goods can be moved with the assistance of lifting power from a lifting aid. This minimizes physical strain.

So that the weight acting on the part of an arm and / or a hand attached to the lifting aid is as low as possible, the lifting force support of the lifting aid can act directly on the suction gripping element.

In order to enable the holding force to be exerted with more than one suction gripping element, the lifting device comprises at least two suction gripping elements. The holding force can thus be applied redundantly, which increases reliability. In order to enable particularly intuitive movement of the goods, a physiological gripping and lifting process can take place when moving the goods. The physiological gripping and lifting process secures the goods redundantly, which greatly minimizes the risk of the goods falling down, which can lead to damage to the goods and / or the operator.

The lifting force assistance and / or the exertion of the holding force with the suction gripping element can be switched on and / or off with at least one operating element as required. Thus, the lifting force assistance and / or holding force with the suction gripping element are only exerted when this is desired by the operator and switching on and / or off is easily possible with the operating element.

Figur 1

eine schematische Darstellung einer Hebevorrichtung;

Figur 2

ein an einer Hand befestigtes Sauggreifelement;

Figur 3

ein Gut, welches von zwei analog wie in Figur 2 ausgestalteten Sauggreifelementen und Händen gehalten wird; und

Figur 4

eine Prinzipskizze der Hebevorrichtung.

Preferred embodiments of the invention are explained in more detail below with reference to the figures, for example. Show:

Figure 1

a schematic representation of a lifting device;

Figure 2

a suction gripper attached to a hand;

Figure 3

a good, which of two is analogous to that in Figure 2 designed suction gripping elements and hands is held; and

Figure 4

a schematic diagram of the lifting device.

Figure 1 shows schematically a lifting device 2 which is designed for force support when moving an item 4 according to a preferred embodiment of the invention. The lifting device 2 comprises two suction gripping elements 6l, 6r configured as mirror images of one another and a lifting aid 8. The two suction gripping elements 6 and consequently also their fastening devices 18 are designed mirror images of each other. The left suction gripping element 6l is optimized for receiving the left arm and / or left hand 28; the right suction gripping element 6r is optimized for receiving the right arm and / or right hand 28. For the sake of clarity, the description below usually does not differentiate between devices shown on the right and left in the drawing, since these are designed in the same way except for their mirror images . Thus, all descriptions apply equally to the respective right and left device. The lifting device 2 is optimized for the loose loading and unloading of storage containers, which are particularly suitable for receiving parcels, parcels, mail containers, Suitcases and other pieces of luggage are provided and are always referred to in a uniform generalized manner as goods 4 below.

The lifting aid 8 provides a continuous lifting force support 10 in that it absorbs all or at least part of the weight 12 of the good 4 and / or the suction gripping elements 6 and / or the lifting aid 8 via a pull rope 14. The pull rope 14 is wound or unwound when it is raised and lowered.

With the suction gripping elements 6, which each comprise a suction cup 16 and a fastening device 18, a holding force 20 can be exerted on the item 4. An operating element 22 is arranged directly on the suction gripping element 6 and the fastening device 18, with which the holding force 20 of the suction gripping element 6 and the lifting force support 10 of the lifting aid 8 can be applied in an uncomplicated manner without large additional movements and thus without major disruptions in the sequence of movements, such as multiple changes of grip. and can be switched off. For this purpose, the operating element 22 comprises one or more switches with which the lifting force support 10 and holding force 20 are activated and deactivated individually by pressing.

The exact design of the suction cup 16 is optimized for the respective specific area of application of the lifting device 2, in particular with regard to the goods 4 to be relocated. Heavy goods 4 in particular, especially if they also have irregular surfaces, require a particularly powerful suction cup 16. The holding force is 20 exerted with the help of negative pressure. In order to increase the negative pressure and thus the holding force 20 that can be exerted by the suction cup 16, the suction cups 16 are connected to a negative pressure source, for example a vacuum pump, via pneumatic lines 24r, 24l, 24. connected. The pneumatic lines 24r, 24l, which run spirally around the pull cords 14, are supplied by a common supply line 24. Negative pressure can also be generated with an ejector module that includes a compressed air nozzle. For this purpose, the ejector module is designed to deactivate the holding force 20 exerted by the suction cup 16 by releasing the negative pressure by directing a short blast of compressed air into the suction cup 16 in order to prevent the suction cup 16 from sticking.

The lifting force support 10 acts directly on the suction gripping elements 6. One task of the suction gripping elements 6 is to transfer the weight of the item 4 to the pull rope 14. In addition, the suction gripping elements 6 represent an operating interface. Since the weight force 12 is not first absorbed via the body part and passed on to the lifting aid 8, an operator 32 is only slightly stressed when moving the goods 4. In order to always ensure optimal positioning of the lifting aid 8 over the item 4, the lifting aid 8 is attached to a suspension 26 which is designed to be movable horizontally and vertically. The lifting device 2 is preferably designed to automatically follow the operator's movements.

The fastening device 18, with which the suction gripping element 6 can be attached to a body part, in particular part of an arm and / or a hand 28 of the operator 32, enables the suction gripping element 6 to be moved together with the body part without it having to be actively held. This considerably simplifies handling; in addition, both hands 28 of the operator can be used as a gripping and lifting tool. In this way, a redundant exercise of both the holding force 20 on the good 4 and the lifting force support 10 is made possible. Redundant in a double sense, because there are at least two body parts, in particular two hands 28 and / or arms, and two suction gripping elements 6 available. The holding force 20 can be exerted on the one hand with the suction cup 16 and on the other hand with the hand 28 of the operator 32.

In order to make the redundant exercise of the power assistance particularly easy, the fastening device 18 is arranged in such a way that the item 4 can be gripped both with the suction cup 16 and with the hands 28, even if part of an arm and / or a hand 28 is with the fastening device 18 is connected. The hands 28 of the operator 32 can therefore continue to perform normal gripping movements. If the suction cup 16 does not grip properly or loses contact - because the surface structure of the item 4 does not allow gripping with the suction cup 16 or due to a malfunction, for example a power failure - the item 4 can be caught and held using the hands 28. In addition, the design of the fastening device also supports the operator when the lifting force and / or holding force are exerted by the operator.

In this way, the fastening device 18 is particularly adapted to support manual gripping, which makes the use of the lifting device 2 highly intuitive. During manual gripping, a large part of the weight force 12 is absorbed by the lifting aid 8 via the fastening device 18 and the suction gripping element 6, so that the hand 28 and fingers are stressed as little as possible. A transfer of the lifting force from the hands 28 to the fastening device 18 and thus the lifting aid 8 is thus optimized.

Even if the power assistance of the lifting device 2 fails, the suction gripping element should support the movement of the good 4. In particular, the load on the hands 28 and individual fingers is very high when gripping a heavy item 4 without any force support. For this purpose, a gripping support integrated into the fastening device 18 is used to avoid or reduce unfavorable stresses on individual areas of the hands 28. The gripping support can be designed like a loop, such as is used in gymnastic or training gloves. A fastening device 18 designed as a complete glove also fulfills this purpose.

Both the exertion of the holding force 20 and the absorption of the weight force 12 are thus redundantly secured. The weight 12 of the good 4 is absorbed directly by the lifting aid 8 with its lifting force support 10 via the pulling rope 14. The suction gripping elements 6 with the suction cups 16 exert a holding force 20 on the item 4. If one or even both force supports fail, the good 4 will still not fall to the ground, since the good 4 is additionally held manually with one or two hands 28. Even in this unfavorable case, the lifting device 2 still assists in moving the goods 4.

In order to move the item 4, both suction gripping elements 6r, 6l, but at least one of them, are first attached to at least one body part, in particular part of an arm and / or a hand 28. A holding force 20 is then exerted on the item 4 and the item 4 is moved. The holding force 20 is exerted on the item with the suction gripping elements 6r, 6l and, additionally, redundantly secured, with the hands 28. In the event of failure of one or both suction gripping elements 6r, 6l, the product 4 is handled solely with the hands 28 held with a physiological gripping process. The goods 4 themselves are moved with the lifting force assistance 10 of the lifting aid 8, which acts directly on the suction gripping elements 6r, 6l, with the operator performing a physiological lifting process redundantly. The lifting force support 10 of the lifting aid 8 and / or the exertion of the holding force 20 with the suction gripping elements 6r, 6l is switched on with the operating elements 22r, 22l as required.

Figure 2 shows a suction gripping element 6 with a fastening device 18 configured as a loop. The loop and thus the entire suction gripping element 6 are fastened to the right hand 28 of an operator 32. The loop runs around the hand 28 below the thumb in such a way that both the thumb and the fingers can move freely. The design of the fastening device 18 as a loop enables both a quick and uncomplicated pick-up of the hand 28 and the use of the hand 28 of the operator 32 as a gripping tool and also serves as a gripping aid. A switch that can be operated with the thumb is attached to the loop as an operating element 22, with which both the holding force 20 exerted by the suction cup 16 and the lifting force support 10 can be activated and deactivated.

The suction cup 16 is connected to the fastening device 18 via a connecting piece 30 running below the thumb over the ball of the hand. Since the pull rope 14 of the lifting aid 8 as well as in Figure 1 acts directly on the suction cup 16, when the suction cup 16 exerts a holding force 20 on an item 4, all or at least a portion of the weight 12 is absorbed by the lifting aid 8 without straining the hand 28. The pneumatic line 24 runs around the pull rope 14 of the lifting aid 8. The suction cup 16 is attached to the connecting piece 30 in a freely rotatable manner. This and the offset arrangement via the connecting piece 30 enables complete freedom of movement of the hand 28. In the event that the holding force 20 cannot be exerted with the suction cup 16, the item 4 can be gripped and aligned with the hand 28. Here, the weight 12 is transmitted from the back of the hand to the loop and finally via the connecting piece 30 to the pulling rope 14 of the lifting aid 8, which absorbs the weight 12 and thus provides lifting force support 10.

Figure 3 shows an item 4 which, according to a preferred embodiment of the invention, is held by two suction gripping elements 6 of the lifting device 2 and additionally redundantly manually by two hands 28. The manual gripping and lifting of the good 4 takes place by performing a physiological gripping and lifting process and is therefore very intuitive. Since the suction gripping elements 6 are arranged in the shadow of the arms, access between two goods 4 standing close together is not hindered.

The suction gripping elements 6 are like those in Figure 1 The suction gripping elements 6r, 6l shown are mirror images of one another, the left suction gripping element 6 being the same as in FIG Figure 2 shown suction gripping element 6 corresponds. The suction gripping element 6 shown on the left in the drawing is optimized for receiving the right hand 28, the suction gripping element 6 shown on the right is optimized for receiving the left hand 28. The lifting force is absorbed by the pull cables 14 around which pneumatic lines 24 lead. The product 4 is held laterally mainly by the suction cups 16 which exert a holding force 20.

Lifting force support 10 and the exertion of the holding force 20 with the suction cups 16 are performed separately by pressing the control element 22 activated with the thumb for each suction gripping element 6 separately. Deactivation takes place by releasing the operating element 22.

Figure 4 shows a schematic diagram of the lifting device 2 according to a preferred embodiment of the invention. An operator 32 is located in a container 34, which serves as a storage container, and builds up a stack of goods 36, the goods 4 being conveyed into the container 34 by a telescopic conveyor 38. The design of the fastening device 18 as a loop, as in FIG Figure 2 and 3 shown, putting on and taking off the suction gripping elements 6 of the lifting device 2 with a simple sliding in and out is uncomplicated and only little time consuming, so that the use of the lifting device 2 can be decided individually for each item 4. As a decision-making aid, there is a display 40 at the end of the telescopic conveyor which shows the weight of the item 4 which is currently at the end of the telescopic conveyor. The display 40 comprises a weight display 40g and a traffic light display 40a. The traffic light display 40a allows a quick visual classification.

When the lifting device 2 is not in use, the suction gripping elements 6 are either on the edge of the telescopic conveyor 38, or they hang at a height at which they have been deposited and can be easily put back on the pulling ropes 14. The suction gripping elements are with With the help of a weight detection system held at this height. To use the lifting device 2, the operator 32 simply slips his hands 28 into the loops, grabs an item 4 and activates the power assistance with the operating elements 22. In the case of an item 4 with a low weight, the traffic light display 40a lights up green and it is not necessary to use the lifting device 2. If a lifting device 2 is used anyway this can restrict the ergonomics of the operator 32, which can lead to one-sided stress and premature fatigue. In the case of heavy goods 4, the traffic light display 40a lights up red and the use of the lifting device 2 is mandatory in order to avoid physical strain damage. In the case of a medium-weight item 4, the traffic light display 40a lights up yellow and the operator 32 can decide for himself, based on his individual physical capacity, whether he would like to use the lifting device 2 or not.

The display 40 enables individual handling of the lifting device 2, depending on the physical requirements of the respective operator 32, without person-specific adaptations being necessary. This would be unfavorable due to the high turnover of personnel.

The pull cords 14 of the lifting aid 8 grip as well as in the Figures 1 to 3 shown directly on the suction gripping elements 6 in order to absorb the weight 12 of the item 4. The operator 32 has put both hands 28 into the fastening device 18, which is designed as a loop, and additionally grips the goods 4 redundantly and manually, which were transported into the container 34 with a telescopic conveyor 38.

So that the pull ropes 14 do not represent an obstacle in his field of vision when the operator 32 leans forward, which is a typical movement in particular when picking up and setting down a good 4, the pull ropes 14 are not designed to converge centrally, but rather on two at a spreader 42 shoulder-width spaced suspension points along. Thus, the pull cords 14 run approximately parallel to the body, and no compensatory movements that hinder a work flow need to be carried out. The suspension 26 comprises the cable spreader 42 and a lightweight boom, which is attached to a beam portal 46 attached to the telescopic conveyor 38. The bar portal 46 is adjustable in height and automatically adaptable to the height of the container with a distance detection. In this exemplary embodiment, the suspension 26 is arranged directly below the container ceiling, as a result of which maximum freedom of movement for the operator 32 is made possible. The lightweight boom 44 has very smooth-running joints and can thus be moved in all vertical directions without noticeable resistance.

The operator 32 picks up the goods 4 from the end of the telescopic conveyor 38 and forms the goods stack 36 in front of him, the goods 4 being nested as precisely as possible on the container wall in order to achieve the highest possible packing density. Since the upper body is usually rotated by 180 degrees, the lightweight boom 44 is designed to ensure at least this freedom of movement. Ideally, however, the operator 32 can rotate several times around his own axis with the fastening device 18 attached to the hands 28. The operator 32 uses a step stool 48 in order to be able to stack the goods 4 even higher than his body size actually allows.

According to a further embodiment, there is a pressure sensor on the suction gripping element 6, which indicates whether a negative pressure is present or not. In this way, the operator can estimate even before the weight of a good 4 is picked up whether his hands 28 are only gripping the good 4 manually to secure it, or whether they have to exert the entire holding force 20.

The ones in the Figures 1 to 4 The sketched arrangement of two suction gripping elements 6 enables a dynamic and fluid workflow through the combination of fastening device 18 which is favorable for exerting the holding force 20 is designed in particular as a loop thus as a findless glove, suction cup 16 and lifting aid 8 with pull cord 14. The arrangement is redundant to the normal gripping process, so that if the lifting device 2 fails, the natural manual gripping and holding process is maintained. Both the lifting force support 10 with the lifting aid 8 and the exercise of the holding force 20 with the suction gripping element 6 can be switched on and off as required.

Instead of activating and deactivating the power assistance with an operating element 22, it is also possible, according to a preferred embodiment, that the fastening device 18 comprises a sensor that activates the power assistance when fastening the suction gripping element 6 to a body part or when releasing the suction gripping element 6 from Body part deactivated. As soon as a good 4 is lifted, weight detection comes into effect. This solution has the advantage that an active actuation of an operating element 22 is not required, which simplifies handling even more. However, the operator first has to provide considerable lifting force himself before the lifting aid 8 is activated. In this embodiment, the lifting aid 8 only takes over part of the weight 12 of the good 12; control takes place by raising and lowering the remaining weight.

So that the hands 28 are not torn up in an uncontrolled manner when a good 4 falls down, the lifting force assistance is interrupted immediately as soon as the weight detection is interrupted. If the power assistance fails in the event of a power interruption or other failures, a brake is activated, which forces the material 4 to be released very slowly.

The handling of the lifting device 2 is extremely simple and intuitive, the at least one suction gripping element 6 can be put on and / or taken off very quickly.

List of reference symbols

2

Lifting device

4th

Well

6th

Suction gripping element

8th

Lifting aid

10

Lifting power assistance

12

Weight force, especially of the goods 4

14th

Pull rope

16

suction cup

18th

Fastening device

20th

Holding power

22nd

Control element

24

Pneumatic line (with supply line)

26th

suspension

28

hand

30th

Connector

32

operator

34

Container

36

Stacks of goods

38

Telescopic conveyor

40

display

40g

Weight display

40a

Traffic light display

42

Rope spreader

44

Lightweight boom

46

Beam portal

48

Step stool

Claims (13)

1. Lifting device (2) which is suitable for power assistance when moving goods (4), comprising at least one lifting aid (8) and at least one suction gripping element (6), wherein

   a) the lifting aid (8) is used for lifting force assistance (10) of the goods (4);

   b) using the suction gripping element (6), a holding force (20) can be exerted on the goods (4), by means of which the goods (4) can be gripped; and

   c) the suction gripping element (6) comprises a fastening device (18) which is suitable for fastening to at least one body part, in particular part of an arm and/or a hand (28);
   characterised in that
   the lifting device (2) comprises at least two suction gripping elements.
2. Lifting device (2) according to claim 1, characterised in that
   the lifting force assistance (10) of the lifting aid (8) engages directly with the suction gripping element (6).
3. Lifting device (2) according to one of claims 1 to 2,
   characterised in that
   the fastening device (18) is designed as a loop for receiving the body part.
4. Lifting device (2) according to one of claims 1 to 3,
   characterised in that
   the suction gripping element (6) is embodied to grip the goods (4) from the side and/or from above and/or from below.
5. Lifting device (2) according to one of claims 1 to 4,
   characterised in that
   at least one operating element (22) is provided for activating and/or deactivating the lifting force assistance (10) of the lifting aid (8) and/or the holding force (20) of the suction gripping element (6).
6. Lifting device (2) according to one of claims 1 to 5,
   characterised in that
   the at least one operating element (22) is arranged directly on the suction gripping element (6) and/or the fastening device (18).
7. Lifting device (2) according to one of claims 1 to 6,
   characterised in that
   the lifting aid (8) is embodied to be movable horizontally and/or vertically.
8. Method for moving goods (4) using a lifting device (2) which comprises at least two suction gripping elements (6), comprising the following method steps

   a) fastening the suction gripping elements (6) respectively to at least one body part, in particular part of an arm and/or a hand (28);

   b) exerting a holding force (20) on the goods (4);

   c) moving the goods (4).
9. Method according to claim 8, characterised in that the holding force (20) is exerted on the goods (4) with the suction gripping element (6) and/or with the at least one body part.
10. Method according to one of claims 8 to 9, characterised in that
    the goods (4) are moved with lifting force assistance (10) of a lifting aid (8).
11. Method according to one of claims 8 to 10, characterised in that
    the lifting force assistance (10) of the lifting aid (8) engages directly with the suction gripping element (6).
12. Method according to one of claims 8 to 11, characterised in that
    a physiological gripping and lifting process occurs when moving the goods (4).
13. Method according to one of claims 8 to 12, characterised in that
    the lifting force assistance (10) and/or the exertion of the holding force (20) with the suction gripping element (6) can be switched on and/or off with at least one operating element (22) as required.

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