Lift truck

Abstract

The invention relates to a pallet truck with a steering tiller, drive mechanism, and a liftable load section to which a vacuum lifting device for lifting panels (e.g., wood, glass) is attached. The vacuum lifting device has a frame with vacuum suction cups and friction-reducing means. The suction cups and friction-reducing means are movable relative to the frame and equipped with a lifting mechanism. The frame is attached to a boom and can be rotated about two axes via rotary / swivel devices, so that the panel can also be rotated by 180°.

Description

[0001] The invention relates to a lifting truck, in particular according to the features of the independent claim.

[0002] Particularly on processing machines for panels, such as wood panels, composite panels, or non-wood panels in woodworking machines or on processing machines for glass panels or similar, the panels, which are often several meters long and just as wide, must be processed on both sides. The comparatively high density of the material to be processed (e.g., wood or wood composite panels, as well as glass panels or panes) and the large surface area result in a high weight. The panel to be processed is therefore no longer manageable by a single machine operator, especially if it needs to be turned from one flat side to the other, i.e., flipped.

[0003] A disadvantage of conventional panel lifters designed to lift these panels is that once the panel has been turned, it rests on the panel lifter with its full weight. Due to the comparatively high friction between the panel lifter and the panel, it is difficult for a machine operator to move the panel from the lifter alone.

[0004] The present invention relates to such objects.

[0005] The object of the present invention is to provide a lifting truck that is improved over the prior art. In particular, it is intended to facilitate easy handling and manual removal of the panel lifted by means of an attached vacuum lifting device.

[0006] This object is achieved by a lifting truck according to the independent claim. The dependent claims describe particularly useful embodiments of the invention.

[0007] A lifting truck according to the invention comprises a steering drawbar, a drive part having a travel drive, and a load part that can be raised and lowered relative to the drive part, wherein a vacuum lifting device is arranged on the load part, wherein the vacuum lifting device is designed to lift a panel, such as a wooden panel, composite panel, non-wooden panel, or glass pane, in particular a vacuum panel lifter, and has a frame with a plurality of vacuum suction cups attached thereto for lifting the panel, with means for reducing the static or sliding friction between the panel and the frame or between the panel and the vacuum suction cups, wherein the vacuum suction cups or the means for reducing the static or sliding friction are mounted so as to be movable towards the panel to be lifted or away from it relative to the frame, wherein a lifting device is assigned to the vacuum suction cups or the means,in order to move the latter selectively towards the plate to be lifted or away from it relative to the frame, the means being fastened to the frame or to the respective vacuum suction cup and comprising a plurality of sliders, rollers, balls, or other conveying devices, in particular conveyor belts or conveyor chains, wherein the frame is fastened to a boom and is mounted relative to the boom via a first rotating / pivoting device for rotation about a first axis of rotation which, in the tensioned state of the plate in which the vacuum suction cups are attached to the plate, is perpendicular to the plate. The frame is mounted relative to the boom via a second rotating / pivoting device for rotation about a horizontal, second axis of rotation, the second rotating / pivoting device being configured to permit rotation of the plate by 180°, and the boom being arranged on the load part.

[0008] When the term "plate" is used in the context of the present invention, it means a flat sheet or panel. It could be a wooden board or glass pane, but also a metal or plastic board or a combination thereof. Such a plate has a significantly greater extension in the length or width direction than in the height direction. The plate must have a surface such that a vacuum can be built up between it and the vacuum suction cups of the vacuum lifting device, and this surface must be large enough to lift, move, rotate or turn the plate. As a rule, these are plates with a side length greater than one meter. Plates that can be handled with such a vacuum lifting device, for example, have a maximum side length of three to three.4 meters. The vacuum lifting device is designed so that it can lift, move, turn and lower plates weighing between 10 and 200 kilograms.

[0009] The present invention serves to clamp the panel exclusively on one side, i.e., along its one flat side, using the vacuum lifting device attached to the lifting truck, and then lift, turn, lower, and release it. The panel is thus never clamped in its often sensitive edge area, i.e., its end faces.

[0010] For example, after the panel has been lifted and turned by the vacuum lifting device or the lifting truck, the panel can simply be pushed off the frame or the vacuum suction cups using the means for reducing static or sliding friction. The means for reducing static or sliding friction can be configured such that the static friction is adjusted so that a machine operator can manually move a panel weighing 10 to 200 kg from the frame, for example, onto a machine for further processing. Alternatively, the means can include a drive to transport the panel away from the vacuum lifting device via the means.

[0011] The vacuum suction cups or the means can be assigned a lifting device to move them either toward the panel to be lifted or away from it relative to the frame. In principle, the movement could also occur away from the frame, e.g., to the left or right, or diagonally.

[0012] The lifting device enables clamping, i.e. picking up the plate and lifting it by placing the vacuum suction cups on the plate in a clamping plane. The releasable clamping is achieved by negative pressure using the vacuum suction cups. The clamped flat side of the plate thus coincides with the clamping plane. To ensure that the flat side is in the clamping plane, the vacuum lifting device is positioned over the plate and moved close enough to the plate. The lifting device is then activated to move the vacuum suction cups towards the plate. Once this has happened, a vacuum pump, which will be discussed in more detail later, builds up a vacuum in order to suck the vacuum suction cups onto the plate. Once the negative pressure has been built up between the plate and the vacuum suction cups, the flat side is in the clamping plane.Then, as soon as the negative pressure is great enough, the plate can be lifted from the floor, for example, using the vacuum lifting device with the vacuum suction cups attached to the plate and turned, for example, i.e. moved from one flat side to the other. More precisely, when turning the plate, it is rotated 180° from its previous position, for example around a line parallel to one of its longitudinal or transverse axes. This brings the vacuum lifting device to rest underneath the plate, so that the plate now rests on top of the vacuum suction cups. The vacuum pump is then turned off, so that the negative pressure between the vacuum suction cups and the plate is released. The lifting device is (automatically) operated in such a way that the vacuum suction cups are moved away from the plate, so that the plate now comes to rest on the means for reducing static or sliding friction. Alternatively, the means for reducing sliding friction could be moved upwards.This is the sliding plane. The means form the sliding plane as a support surface for the plate. The plate is thus moved from the clamping plane to the sliding plane by the lifting device to release it from the vacuum lifting device or the vacuum suction cups. In the case described here, this is moved toward the vacuum lifting device into the sliding plane. The means then make it particularly easy for an operator to manually slide the plate off the vacuum suction cups or the frame of the vacuum lifting device.

[0013] The vacuum pump can be controlled in its speed or rotational speed, in particular by means of the control device, so that the negative pressure in the vacuum suction cups is active, i.e. adjustable during operation.

[0014] The total contact surface of all means for reducing static or sliding friction can be smaller than the total contact surface of all vacuum suction cups of the vacuum lifting device in order to further reduce static friction.

[0015] The means can be attached to the frame or to the respective vacuum suction cup. They can also be formed as a single piece with the respective vacuum suction cup.

[0016] From a design perspective, it is particularly simple and cost-effective to implement if the means comprise a plurality of sliders, rollers, or balls, or other conveying devices, particularly conveyor belts or conveyor chains. The conveyor belts or chains can also be actively driven by appropriate drives.

[0017] The frame can be attached to a boom and mounted so as to be rotatable relative to the boom via a first rotating / pivoting device about a first axis of rotation which, when the plate is clamped and the vacuum suction cups are attached to the plate, is perpendicular to the plate. The plate can therefore be freely pivoted about the first axis of rotation in both directions of rotation about the perpendicular to its surface. The first rotating / pivoting device can be designed such that it allows a full rotation (360° and more) of the frame relative to the boom. This can be achieved, for example, by a corresponding rotary feedthrough for the negative pressure to the vacuum suction cups and slip rings for the power supply to the first rotating / pivoting device through the first rotating axis. In this way, excessive kinking or movement of the lines, such as hoses that connect the vacuum suction cups to the vacuum pump in a fluid-conducting manner, is avoided.

[0018] The frame can be mounted for rotation relative to the boom about a horizontal, second axis of rotation via a second rotation / pivot device. The second rotation / pivot device can be configured to allow the plate to rotate by 180°. This allows the plate to be easily pivoted, for example, about a line parallel to its transverse or longitudinal axis, so that it can be turned. The first and second axes of rotation can be arranged perpendicular to each other.

[0019] It's advantageous to have a scale attached to the vacuum lifting device to measure the weight of the lifted panel. This allows the operator to immediately assess (after clamping the panel with the vacuum suction cups) whether or not they can still lift the panel themselves.

[0020] As already described, a vacuum pump can be assigned to the vacuum lifting device to lift the plate by selectively creating a vacuum between the plate and the vacuum suction cups, and to release it from the vacuum suction cups again by releasing the vacuum. The vacuum in the vacuum suction cups during the plate lifting process can be detected or calculated using a corresponding sensor. This has the advantage that the vacuum can also be monitored for safety reasons.

[0021] Together with the weight recorded on the scale and the negative pressure detected by the sensor, the control unit can calculate a safety factor at which the plate can be safely lifted or swiveled. Depending on the safety factor, the plate can then only be lifted, only lifted and swiveled, or lifted, swiveled and turned. This safety factor can be indicated to the user by a colored bar next to the negative pressure and mass display. If the bar is green, for example, the safety factor is sufficient for lifting, swiveling, and turning the plate. If it is orange, for example, the plate may only be lifted horizontally, but parallel to the floor, and may not be swiveled, e.g. at an angle of 90° to the floor, i.e. vertically. The control unit then temporarily switches off the tilt function (swiveling around the second axis of rotation).

[0022] The invention also relates to a combination of vacuum lifting device / lifting carriage and panel, such as a wooden panel or glass pane, wherein the vacuum lifting device / lifting carriage is designed according to the invention.

[0023] A lifting truck according to the invention can serve as a means of transport between two processing machines and facilitate the heavy transport or turning of the panels by hand.

[0024] A control device comprising an operating device with a plurality of switches can be assigned to the lifting truck, wherein the load part can be selectively raised relative to the drive part by actuating a first switch and lowered by means of a second switch.

[0025] Preferably, the lifting truck can be assigned a control device, comprising an operating device with a plurality of switches, wherein by actuating a first switch, the load part can be selectively raised relative to the drive part and lowered by means of a second switch, wherein the control device is preferably connected to the first rotating / pivoting device, so that the actuation of a third switch causes the first rotating / pivoting device to rotate the frame relative to the boom about the first axis of rotation and the actuation of a fourth switch causes the first rotating / pivoting device to rotate the frame in an opposite direction of rotation relative to the boom about the first axis of rotation, wherein the control device is preferably connected to the second rotating / pivoting device,such that the actuation of a fifth switch causes the second rotating / pivoting device to rotate the frame relative to the boom about the second axis of rotation and the actuation of a sixth switch causes the second rotating / pivoting device to rotate the frame in an opposite direction of rotation relative to the boom about the second axis of rotation, wherein the control device is preferably connected to the vacuum pump, such that the actuation of a seventh switch causes the vacuum pump to build up the negative pressure and the actuation of an eighth switch causes the vacuum pump to reduce the negative pressure, wherein the control device is preferably connected to the lifting device,so that the actuation of the seventh switch causes the lifting device and thus the vacuum suction cups to move towards the plate to be lifted and the actuation of the eighth switch causes the lifting device to move away from the plate to be lifted.

[0026] Advantageously, the first to eighth switches are virtual switches whose corresponding function can be assigned to exactly two physical switches.

[0027] According to one embodiment, the control device is associated with a display that is connected to the control device. Preferably, the scale is connected to the control device to transmit the weight of the plate to the control device and to display the weight of the lifted plate on the display. Preferably, the sensor is connected to the control device to transmit the negative pressure during the lifting of the plate to the control device, in order to display the negative pressure on the display. Thus, the safe operation of the vacuum lifting device can be monitored by the operator via the display.

[0028] Preferably, the first to eighth switches point to memory registers of a CPU of the control device, wherein preferably the first to eighth switches are designed as software switches, such as touch switches of a display of the operating device designed as a touchscreen.

[0029] Advantageously, any position of the boom relative to the load part of the pallet truck or the frame to the boom can be saved.

[0030] According to one embodiment, when a ninth switch, which is also a virtual switch, is pressed, the positions stored in the memory register of the control device are recalled and moved to. This allows the operation of the lift truck to be partially automated.

[0031] The vacuum pump can be designed to be controllable in terms of its performance, i.e., the level of negative pressure. The control device can then adjust the vacuum pump's performance in such a way that the negative pressure generated by the vacuum pump is adapted to the weight of the panel to be lifted, allowing the vacuum lifting device to fully lift the panel without it falling. This always ensures the optimal, actually required clamping force is set. At the same time, the energy consumption and noise emissions caused by the vacuum pump are reduced.

[0032] The control device can control the vacuum pump and the lifting device in such a way that when the plate is turned over, i.e., as soon as the plate comes to rest above the vacuum lifting device, the vacuum pump is automatically switched off by the control device or a switch, such as a limit switch, and the plate therefore comes to rest on the means. A corresponding sensor can be provided, which is connected to the control device and detects the turning of the plate.

[0033] The first to eighth switches can be virtual switches whose corresponding function can be assigned to exactly two physical switches. The first to eighth switches could also point to memory registers of a CPU in the control unit or be software switches, such as touch switches on a display in the operating unit designed as a touchscreen. Any position of the boom relative to the load section of the lifting truck or of the frame to the boom could also be saved, so that when a ninth switch, which could also be a virtual switch, is pressed, these positions, particularly those saved in the memory register of the control unit, could be called up again and approached (so-called teach-in function). Approaching the positions can be determined, for example, using linear position measuring systems, such as displacement encoders or displacement sensors, such as pull-cable encoders or pull-cable displacement sensors for the height and angular positions of the vacuum frame relative to the boom.The advantage here is that, for example, after lifting the plate from the ground, the frame or boom is moved to the previously saved position with the load part by pressing the ninth switch.

[0034] The pallet truck can be equipped with two of the aforementioned position sensors. This allows the height of the boom relative to the load or drive section to be recorded or measured, as well as the angle at which the frame moves relative to the boom.

[0035] The pallet truck can be used for handling on a processing machine. This allows it to travel along a guide rail, with a detection strip mounted on this guide rail at any desired position. The guide rail can be the one that forms the load section along which the boom with the vacuum lifting device moves. This detection strip can be used to set the stopping position of the pallet truck. In a program running in the control unit, the pallet truck can now automatically execute a program as follows. For example, to pick a panel from a stack and place it on an infeed roller conveyor of the processing machine, the cycle would look like this: Raise the boom, e.g. to a height of 160 cm; move to a first position; move downwards at rapid traverse until the stack is detected; then move downwards at creeping speed until the mass of the vacuum lifter frame is no longer detected by the scale; switch on the vacuum pump; raise the panel to transport height; move the panel to a second position which corresponds to a roller conveyor of the processing machine; lower the panel to the roller conveyor height; switch off the vacuum pump.

[0036] The lift truck can be equipped with a power supply, e.g., in the form of a battery, that supplies the aforementioned devices, such as the vacuum pump, the lifting devices, the control device, the scales, and the sensors, as well as the rotating / swivel devices and the drive or load section of the lift truck—e.g., in the form of an electric drive. Alternatively, the drive section can be manually driven.

[0037] The invention also relates to a combination of a vacuum lifting device or a lifting truck with a processing machine for a panel, such as a wood or glass processing machine.

[0038] The advantages of the invention will now be explained in more detail with reference to a preferred embodiment and the figures.

[0039] It shows: Fig. 1 shows a spatial representation of a vacuum lifting device according to an embodiment; Fig. 2 shows a side view of a lifting truck with a vacuum lifting device according to an embodiment in a first position; Fig. 3 shows the object from Fig. 2 in a second position; Fig. 4 the object from Fig. 2 or 3 in a third position; Fig. 5 a detailed view of the vacuum lifting device in the position Fig. 4 .

[0040] In Fig. 1 A three-dimensional representation of a vacuum lifting device 1 according to one embodiment is shown. The vacuum lifting device 1 serves to lift a panel 2, such as a wooden panel or glass pane, and comprises a frame 3. The frame 3 is made of two spaced-apart longitudinal beams 4 and several, here four, cross beams 5, which are slidably mounted on the longitudinal beams 4 and can be fixed in the desired position.

[0041] The vacuum lifting device 1 comprises a plurality of vacuum suction cups 6 attached to the frame 3, more precisely, to the crossbeams 5, for raising and lowering the panel 2. The vacuum suction cups 6 can, in turn, be movable and fixable along the frame 3 or the respective crossbeam 5. Due to this movable nature, the vacuum suction cups 6 can be easily positioned across the width and length of the frame 3 to accommodate smaller or larger panels 2.

[0042] A vacuum pump 15 is assigned to the vacuum lifting device 1 to raise or lower the plate 2 by selectively building up a negative pressure between the plate 2 and the vacuum suction cups 6, i.e., in the clamped state, and to release it from the vacuum suction cups 6 again by releasing the negative pressure. For this purpose, the vacuum suction cups 6 can be fluidly connected to the vacuum pump 15 via lines (not shown), such as hoses. Appropriate valves can be provided to regulate the flow of air in the lines, e.g., to release or interrupt it, in order to specifically build up or release the vacuum in the vacuum suction cups 6.

[0043] The negative pressure in the vacuum suction cups 6 when lifting the plate 2 can also be detected or calculated using a corresponding sensor (not shown). A scale (also not shown) can also be assigned to the vacuum lifting device 1 to measure the weight of the lifted plate 2. Both devices serve as safety measures to increase occupational safety for the operator.

[0044] The vacuum lifting device 1 is provided with means 7 for reducing the static or sliding friction between the plate 2 and the frame 3 or between the plate 2 and the vacuum suction cups 6, which are merely indicated here by the dashed circles. The means 7 can be designed as sliders, rollers, or balls and, as indicated here, can be attached to the frame 3. These then serve to lift the plate 2, particularly in the Fig. 4 shown position after the negative pressure in the vacuum suction cups 6 has been reduced from the frame 3, e.g. by hand.

[0045] Furthermore, the vacuum suction cups 6 or the means 7 for reducing static or sliding friction can be mounted so that they can move relative to the frame 3 toward or away from the plate 2 to be lifted. For this purpose, a lifting device 8 can be assigned to the vacuum suction cups 6 or the means 7 in order to move the vacuum suction cups 6 or the means 7 selectively toward or away from the plate 2 to be lifted relative to the frame. In the present case, each vacuum suction cup 6 is assigned its own lifting device 8.

[0046] Fig. 2 shows a side view of a lifting truck 9 with the vacuum lifting device 1 according to an embodiment in a first position of the vacuum lifting device 1, in which it is placed on the plate 2 to be lifted. The frame 3 of the vacuum lifting device 1 is attached to a boom 10. The boom 10 can thus raise or lower the plate 2 together with the vacuum lifting device 1. In the clamped state, i.e. in which the vacuum suction cups 6 are firmly suctioned to the plate 2, the plate 2 can be rotatably mounted about a first axis of rotation 11, which is perpendicular to the plate 2, relative to the boom 10 via a first rotating / pivoting device 12. By means of the first rotating / pivoting device 12, the plate 2 can be pivoted or rotated about the first axis of rotation 11 as soon as it has been lifted off the ground, for example. The first rotating / swivelling device 12 can be designed, for example, as a motor arranged concentrically to the first rotation axis 11.

[0047] The frame 3 is mounted for rotation relative to the boom 10 about a horizontal, second rotation axis 13 via a second rotation / pivot device 14. The second rotation / pivot device 14 can, as shown, be designed as a piston-cylinder combination, such as a hydraulic or pneumatic cylinder, with additional levers connected to it. The first and second rotation axes 11 and 13 can be arranged perpendicularly and, in particular, spaced apart from one another.

[0048] The second rotating / pivoting device 14 can be designed in such a way that it allows a rotation of the plate 2 by 180°, compare the Fig. 2 and 4 .

[0049] The lifting truck 9 comprises a steering drawbar 16, a drive section 17 with a travel drive, and a load section 18 that can be raised and lowered relative to the drive section 17. The vacuum lifting device 1 is arranged on the load section, in particular via the boom 10 on the load section 18. The load section 18 can have a telescopic extension that can raise and lower the boom, thus enabling, for example, lifting heights of the panel of up to 2.4 m.

[0050] As in Fig. 3 As shown, the plate 2 is now firstly supported by means of the load part 18 and the boom 10 starting from the Fig. 2 The plate 2 was raised vertically into the position shown and then pivoted into the vertical position. The latter was achieved by actuating the second rotation / pivot device 14, so that the plate 2, including the vacuum lifting device 1, was pivoted relative to the boom 10 about the second rotation axis 13.

[0051] In Fig. 4 The position is shown in which the plate 2 is lifted by the lifting carriage 9 from the position in Fig. 2 The plate 2 now rests on the vacuum lifting device 1. In the detailed view of the Fig. 5 One can clearly see again that the means 7, designed here as rollers, for reducing the static or sliding friction or for conveying the plate 2 from the vacuum lifting device 1, for example, to a processing machine, are located under the plate 2. One can see from the detailed representation of the Fig. 5 It is good that the clamped flat side of the plate 2 simultaneously forms the clamping plane S. This clamping plane S is clamped by the vacuum suction cups 6 that are firmly attached to the plate 2. In this position, the vacuum suction cups 6 are displaced by the lifting device 8, starting from the frame 3, toward the plate 2. They thus indicate the clamped state of the plate 2.

[0052] If it is desired to release the plate 2 from the vacuum lifting device 1, the negative pressure in the vacuum suction cups 6 can be released, which can be done, for example, by switching off the vacuum pump 15 or by venting the vacuum suction cups 6 or their supply lines. After the pressure has dropped, the lifting device 8 is actuated such that the vacuum suction cups 6 are released from the plate 2 and moved away from the plate 2 onto the frame 3. The plate 2 now comes to rest on the means 7 for reducing static or sliding friction, in this case the rollers. In this case, it is lowered with the vacuum suction cups 6 and brought into the sliding plane G. The flat side of the plate 2 facing the vacuum lifting device 1 thus coincides with the sliding plane G. The sliding plane G is spanned by the means 7. The plate 2 can now be moved along the sliding plane G, for examplecan be easily moved by hand without the vacuum suction cups 6 getting in the way and without the plate 2 having to be lifted manually by the operator.

[0053] As in the Fig. 2 bis 4 As shown, the lifting carriage 9 is assigned a control device 19 which comprises an operating device 20. The latter has a plurality of switches for selectively raising or lowering the load part 18 relative to the drive part 17, for causing the first rotating / pivoting device 12 to rotate the frame 3 relative to the boom 10 about the first axis of rotation 11, for causing the second rotating / pivoting device 14 to rotate the frame 3 relative to the boom 10 about the second axis of rotation 13, for causing the vacuum pump 15 to build up or reduce the negative pressure, or for causing the lifting device 8 and thus the vacuum suction cups 6 to stroke towards or away from the plate 2 to be lifted.

[0054] Furthermore, the control device 19 - more precisely the operating device 20 - can be assigned a display 21 which is connected to the operating device 20 or more precisely to the control device 19 in order to transmit, for example, the weight of the plate 2 determined by the scales to the control device 19 and output this on the display 21. It is also conceivable that the sensor for determining the negative pressure in the vacuum suction cups 6 is connected to the control device 19 in order to transmit the negative pressure when lifting the plate 2 to the control device 19, with the aim of outputting the negative pressure on the display 21. In this way, the operator of the lifting truck can ensure that the plate is lifted with the correct, i.e. sufficient, negative pressure that is capable of holding it securely during lifting, lowering and turning. Reference symbol

[0055] 1Vacuum lifting device 2Plate 3Frame 4Longitudinal beam 5Cross beam 6Vacuum suction cup 7Means for reducing static or sliding friction 8Lifting device 9Lift carriage 10Boom 11First rotation axis 12First rotation / swivel device 13Second rotation axis 14Second rotation / swivel device 15Vacuum pump 16Steering drawbar 17Drive section 18Load section 19Control device 20Operating device 21Display GGliding plane SSpanning plane

Claims

1. Lifting truck (9) with a steering drawbar (16), a drive part (17) having a travel drive, and a load part (18) which can be raised and lowered relative to the drive part (17), wherein a vacuum lifting device is arranged on the load part (18), wherein the vacuum lifting device (1) is designed to lift a panel (2), such as a wooden panel, composite panel, non-wooden panel, or glass pane, in particular a vacuum panel lifter, and comprises a frame (3) with a plurality of vacuum suction cups (6) attached thereto for lifting the panel (2), with means (7) for reducing the static or sliding friction between the panel (2) and the frame (3) or between the panel (2) and the vacuum suction cups (6), wherein the vacuum suction cups (6) or the means (7) for reducing the static or sliding friction are movable towards the panel (2) to be lifted or away from it relative to the frame (3). are mounted, wherein the vacuum suction cups (6) or the means (7) are assigned a lifting device (8),in order to move the latter selectively towards the plate (2) to be lifted or away from it relative to the frame (3), the means (7) are fastened to the frame (3) or to the respective vacuum suction cup (6) and comprise a plurality of sliders, rollers or balls or other conveying devices, in particular conveyor belts or conveyor chains, wherein the frame (3) is fastened to a boom (10) and is mounted rotatably about a first axis of rotation (11) - in the tensioned state of the plate (2), in which the vacuum suction cups (6) are fastened to the plate (2) - perpendicular to the plate (2) relative to the boom (10) via a first rotating / pivoting device (12), wherein the frame (3) is mounted rotatably about a horizontal, second axis of rotation (13) relative to the boom (10) via a second rotating / pivoting device (14), the second rotating / pivoting device (14) is configured such thatthat it allows a rotation of the plate (2) by 180° and the boom (10) is arranged on the load part (18)., 2. Lifting truck (9) according to claim 1, characterized in that the vacuum lifting device (1) is assigned a scale to record the weight of the lifted plate (2).

3. Lifting truck (9) according to claim 1 or 2, characterized in that a vacuum pump (15) is assigned to the vacuum lifting device (1) in order to lift the plate (2) by selectively building up a negative pressure between the plate (2) and the vacuum suction cups (6) and to release it again from the vacuum suction cups (6) by reducing the negative pressure.

4. Lift truck (9) according to claim 3, characterized in that the negative pressure when lifting the plate (2) in the vacuum suction cups (6) is detected or calculated via a corresponding sensor.

5. Lift truck (9) according to claim 4, characterized in thata control device (19) is assigned to the lifting truck (9), comprising an operating device (20) with a plurality of switches, wherein the load part (18) can be selectively raised relative to the drive part (17) by actuating a first switch and lowered by means of a second switch, wherein the control device (19) is preferably connected to the first rotating / pivoting device (12) such that the actuation of a third switch causes the first rotating / pivoting device (12) to rotate the frame (3) relative to the boom (10) about the first axis of rotation (11) and the actuation of a fourth switch causes the first rotating / pivoting device (12) to rotate the frame (3) in an opposite direction of rotation relative to the boom (10) about the first axis of rotation (11), wherein the control device (19) is preferably connected to the second rotating / pivoting device (14),such that the actuation of a fifth switch causes the second rotating / pivoting device (14) to rotate the frame (3) relative to the boom (10) about the second axis of rotation (13) and the actuation of a sixth switch causes the second rotating / pivoting device (14) to rotate the frame (3) in an opposite direction of rotation relative to the boom (10) about the second axis of rotation (13), wherein the control device (19) is preferably connected to the vacuum pump (15), such that the actuation of a seventh switch causes the vacuum pump (15) to build up the negative pressure and the actuation of an eighth switch causes the vacuum pump (15) to reduce the negative pressure, wherein the control device (19) is preferably connected to the lifting device (8),so that the actuation of the seventh switch causes the lifting device (8) and thus the vacuum suction cups (6) to be lifted in the direction of the plate (2) to be lifted and the actuation of the eighth switch causes the lifting device (8) to be lifted in the direction away from the plate (2) to be lifted.

6. Lift truck according to claim 5, characterized in that the first to eighth switches are virtual switches whose corresponding function can be assigned to exactly two physical switches.

7. Lift truck according to claim 5 or 6, characterized in thatthe control device (19) is assigned a display (21) which is connected to the control device (19), wherein the scale is preferably connected to the control device (19) in order to transmit the weight of the plate (2) to the control device (19) and to output the weight of the lifted plate (2) on the display (21), wherein the sensor is preferably connected to the control device (19) in order to transmit the negative pressure when the plate (2) is lifted to the control device (19) in order to output the negative pressure on the display (21).

8. Lift truck according to one of claims 5 to 7, characterized in that the first to eighth switches point to memory registers of a CPU of the control device, wherein preferably the first to eighth switches are designed as software switches, such as touch switches of a display of the operating device designed as a touchscreen.

9. Lift truck according to claim 8, characterized in thatany position of the boom relative to the load part of the pallet truck or the frame to the boom can be saved.

10. Lift truck according to claim 9, characterized in that When a ninth switch, which is also a virtual switch, is pressed, the positions stored in the memory register of the control device can be recalled and approached again.

Images