Width-adjustable unmanned conveyor

Abstract

The present invention relates to an unmanned transport device (1) for picking up, transporting, lifting and transferring closed-bottom pallets (21) and open-bottom pallets (22) automatically, in a space-saving manner and without collision. The wheel arms (2, 2a) of the chassis, which are substantially U-shaped in plan view, can be displaced together or independently of each other in a transverse direction relative to the base unit (8) or the lower part (10) of the base unit of the transport device (1), and in a first position can be arranged side by side below and in a second position laterally along the width of the transport device and spaced apart from the tines (4, 4a) of the lifting forks, where the tines (4, 4a) of the lifting forks together with the rear wall (5) of the lifting forks can be moved independently of the wheel arms (2, 2a) relative to the base unit (8) or independently of the wheel arms (2, 2a) relative to the lower part (10) of the base unit, and the transport device (1) can be moved in all directions along any trajectory from any first point to any second point. In this way, open-bottomed pallets having a width smaller than the width of the transport device can be picked up and placed flush, for example on the inner wall of a loaded container or other lateral boundary surface, without collision. The unmanned transport device (1) according to the invention is particularly lightweight, does not require counterweights, has minimal energy consumption, has minimal requirements for space and does not require further equipment.

Description

[Technical field]

[0001] The present invention relates to a driverless transport device for picking up, transporting, lifting and transferring closed and open-bottom pallets automatically, space-saving and without collisions, comprising a chassis essentially U-shaped in plan view, with a base unit, two legs and a lifting device consisting of a lifting carriage with lifting forks attached and a vertical guide. [Background technology]

[0002] An open-bottom pallet is a pallet with an open-bottom recess, which can be moved downwards by forks that rotate on the floor. In the case of a closed-bottom pallet, only a closed recess is available, into which the tines of the lifting forks raised from the floor can be inserted. In the following description, the term pallet always includes the items stored on the pallet.

[0003] According to the prior art, counterbalanced forklifts, such as those disclosed in US Design Patent No. 597622, ​​US Patent Application Publication No. 2021 / 0395060 and DE Patent Application Publication No. 10321773, comprise lifting forks which are fixed or laterally adjustable on a lifting device (e.g. on a lifting mast) and a chassis arranged opposite said lifting forks, the weight of which, for stability reasons, requires several times the lifting load, which requires high energy consumption and the drive system does not allow unrestricted omnidirectional movement along any track, requiring a maneuvering area of ​​the order of several times the footprint of the pallet.

[0004] Furthermore, DE 102021115805, CN 113968554 and EP 3034453 disclose devices for translational lateral movement of forklifts and similar self-propelled working machines having forks (lifting forks), which, when attached to an arm or lifting device, allow lateral movement in a first direction of movement of the lifting fork. The working machines disclosed as counterbalanced forklifts require their own weight to be several times the lifting load for stability reasons, have high energy consumption and a maneuvering area of ​​the order of several times the footprint of a pallet.

[0005] DE 102016123326 A1 discloses a high-lift industrial truck with forks with a fixed fork spacing, which are vertically movable in a lift frame, and vertically aligned and fixed wheel arms. The fixed design of the support wheels in the wheel arms does not allow unlimited omnidirectional movement along any trajectory, requiring a maneuvering area of ​​several times the footprint of the pallet, and the wheel arms arranged in line below the forks do not allow picking up pallets with closed bottoms.

[0006] China Patent Publication No. 11347233, China Patent Publication No. 113493173, Japan Patent Publication No. 2021-151857, US Patent No. 10988155, US Patent Publication No. 2022 / 0041417 disclose low-lift industrial trucks with wheel arms that are laterally adjustable relative to the longitudinal axis of the wheel arms, designed with support wheels or driven non-steerable wheels, and connected vertically side-by-side with vertically movable load attachments designed directly as loading attachments and arranged above them. The support wheels or driven wheels designed fixedly on the wheel arms prevent unlimited omnidirectional movement along any track, requiring a steering area of ​​several times the footprint of the pallet, and the wheel arms arranged side-by-side below the forks make it impossible to pick up pallets with closed bottoms.

[0007] EP 3689813 and EP 3517483 disclose reach trucks with fixedly designed wheel arms and support wheels, which are laterally spaced apart from the load / cargo attachment, and the cargo part is longitudinally movable relative to the wheel arms. The laterally spaced apart wheel arms prevent flush lifting and placing of adjacent pallets without collision with interfaces or other pallets, and the fixedly designed support wheels in the wheel arms prevent unrestricted omnidirectional movement along any trajectory, requiring a maneuvering area of ​​several times the footprint of the pallet.

[0008] DE 102015108993 A1, DK / EP 3626676 A1 discloses a broad-gauge stacker with fixedly mounted wheel arms and with steerable driven wheels or non-driven support wheels on the wheel arms and with a solid load part between the two wheel arms such that the load part is located between the two wheel arms. The wheel arms spaced laterally from the load part make it impossible to raise and lower or place the pallet flush without colliding with an interface or with another pallet.

[0009] EP 2336075 discloses an unmanned transport system for automatically picking up, transporting and transferring pallets, where the transport system is designed with a U-shaped chassis, an omnidirectional drive and lifting forks arranged side-by-side on the U-shaped chassis, so that only open-bottom pallets can be handled.

[0010] WO 2021 / 223351 discloses a system for loading and unloading a goods container, comprising a first vehicle system and a second vehicle system, the first vehicle system being a conventional forklift truck that cannot be driven into the goods container due to its large size, and the second vehicle system being a non-steerable shuttle vehicle that can load and unload goods into and from the goods container along a linear travel path. The first vehicle system has a large self-weight and requires several times the lifting load for stability, resulting in high energy consumption, and the drive system of the first vehicle system and the second vehicle system does not allow unlimited omnidirectional movement along any trajectory, requiring a maneuvering area of ​​several times the footprint of a pallet.

[0011] DE 10 2015100815 A1 discloses a truck-mounted forklift consisting of a frame with a drive part and a lifting frame and a chassis part with two parallel spaced-apart wheel arms carrying load wheels, whereby two of said wheel arms are connected to the drive part by torsionally rigid non-circular guides, one wheel arm on the left and one wheel arm on the right are inserted from the sides of the frame, whereby said wheel arms can be laterally adjusted in a stepless or rasterized manner in the transverse axis of the truck, and whereby the minimum clear width of said wheel arms corresponds to the width of the drive part with the lifting frame. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] U.S. Design Patent No. 597622 [Patent Document 2] US Patent Application Publication No. 2021 / 0395060 [Patent Document 3] DE 10321773 A1 [Patent Document 4] DE 102021115805 [Patent Document 5] China Patent Publication No. 113968554 [Patent Document 6] European Patent Application Publication No. 3034453 [Patent Document 7] DE 102016123326 [Patent Document 8] China Patent Publication No. 11347233 [Patent Document 9] China Patent Application Publication No. 113493173 [Patent Document 10] Japanese Patent Application Publication No. 2021-151857 [Patent Document 11] U.S. Pat. No. 1,098,8155 [Patent Document 12] US Patent Application Publication No. 2022 / 0041417 [Patent Document 13] European Patent No. 3689813 [Patent Document 14] European Patent No. 3517483 [Patent Document 15] DE 102015108993 A1 [Patent Document 16] Danish Patent / European Patent No. 3626676 Translation [Patent Document 17] European Patent No. 2336075 [Patent Document 18] International Publication No. 2021 / 223351 [Patent Document 19] DE 102015100815 Summary of the Invention [Problem to be solved by the invention]

[0013] The unmanned lifting and transporting devices known from the prior art in particular do not allow automatic handling of open-bottom or closed-bottom pallets in a limited space without collision, automatic picking up, transporting and handing over said pallets which are, for example, laterally flush with the inner wall surface or other lateral boundary surface of the loaded container, unlimited omnidirectional movement of the transporting device along any trajectory from any first point to any second point, with or without a load, i.e. forwards, backwards, sideways at any angle to the first direction of movement, in a straight line or diagonally, and around any vanishing point (i.e. even while rotating at a standstill), with only a single lifting and transporting device and without further auxiliary devices, with the lowest possible energy consumption and the smallest possible space requirement.

[0014] The invention is based on the problem of being able to manipulate both closed-bottom and open-bottom pallets with a minimum of space requirements and without collisions, even during transportation in narrow traffic areas. [Means for solving the problem]

[0015] This problem is solved by an unmanned transport system in which the two legs of a U-shaped chassis are designed as transversely adjustable wheel arms which in a first position can be positioned side-by-side below the tines of the lifting forks and in a second position can be positioned laterally outwardly spaced apart from the tines of the lifting forks along the width direction of the transport device.

[0016] This means that the wheel units are attached to legs that protrude forward of the chassis and through which they can support part of the weight of the lifted load, for this reason these legs are also called wheel arms.

[0017] An important feature of the present invention is that open bottom pallets can be run completely downwards, meaning that little lateral space is required against walls or other stored items to receive or place the pallet.

[0018] Pallets with closed bottoms require clearance for the wheel arms to move laterally, but as soon as the pallet is raised or lowered, the wheel arms can move under the pallet, so that the width of the transport device does not exceed the width of the pallet, meaning that transport is possible even in very narrow transport paths.

[0019] The advantages of the present invention are therefore particularly beneficial where a mixture of open bottom and closed bottom pallets are used.

[0020] Preferably, the wheel arms are laterally displaceable together or independently of one another with respect to the base unit of the transport device or the lower part of the base unit. In particular, the independent adjustment has the advantage that the available space can be optimally utilized.

[0021] A variant of the first preferred embodiment of the invention provides that the prongs of the lifting forks are fixedly connected to the rear wall, which means that the lifting fork unit is fixed and can be designed to be particularly rigidly fixed.

[0022] The fact that the rear wall can be moved laterally relative to the base unit or the lower part of the base unit increases the flexibility in the use of the transport device, so that if space does not allow for an optimal positioning of the transport device in front of the pallet and there is a risk of the tines of the lifting forks hitting the pallet, this can be remedied by shifting the lifting fork units.

[0023] In a variant of the alternative embodiment, it is provided that the prongs of the lifting forks are laterally movable independently of one another, which also allows the distance between the lifting forks to be varied depending on the situation.

[0024] Preferably, the wheel arms each have a steerable wheel unit, i.e. can be actively operated. These wheel units can have driven or non-driven wheels. In the case of driven wheels, it is preferred if the two wheels can be driven independently of each other, so that the steering movement can be performed by driving the wheels. If not, a steering motor can be provided. In this context, it is particularly advantageous if the base unit has at least one, preferably at least two steerable drive units. This allows the transport device to be moved in all directions along any trajectory from any first point to any second point, i.e. over the entire area.

[0025] Ground irregularities can be compensated for particularly well if the steerable drive unit is mounted so that it can rotate about a vertical axis and tilt about a horizontal axis.

[0026] It is further preferred if the vertical guide of the lifting device is a simple lifting mast or a telescopic guide device, the lifting drive of the lifting device is, for example, electric, hydraulic or pneumatic, and the lifting movement is transmitted by a chain drive, a belt drive, a threaded spindle drive or a cylinder.

[0027] A particularly maneuverable and space-saving design of the transport device according to the invention can be realised if the wheel arms are laterally displaceable beyond the width of the base unit: in this way, the transport device can be narrowed in width so that it does not normally protrude laterally beyond the pallet, except when the wheel arms extend laterally for lifting and lowering closed-bottom pallets.

[0028] The present invention also relates to a method for manipulating a pallet, in which an unmanned transport device optionally moves two legs of a U-shaped chassis, together with the tines of a lifting fork attached to the U-shaped chassis, under an open-bottom pallet, lifts the tines of the lifting fork and moves the open-bottom pallet, or moves the legs of the U-shaped chassis laterally outward, moves the legs to the sides of the pallet to engage the tines of the lifting fork under the pallet, and then lifts and lowers the tines of the lifting fork to move the pallet.

[0029] Preferably the legs of the U-shaped chassis are moved laterally inwardly beneath the pallet when the pallet is raised.

[0030] Furthermore, the lifting forks can be displaced laterally.

[0031] The invention will now be explained in more detail with reference to non-limiting exemplary embodiments in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0032] [Figure 1] 1 shows a perspective view from above of an automated transport device according to the present invention, with a pallet with a closed bottom resting on the lifting forks and with the wheel arms positioned laterally spaced apart from and outside the pallet. FIG. [Diagram 2] FIG. 2 shows a top perspective view of an unmanned transport device according to the present invention with an open-bottom pallet resting on the tines of the lifting forks, the wheel arms vertically aligned with the tines of the lifting forks, and the lifting forks centered relative to the base unit of the transport device. [Diagram 3] 1 shows a top perspective view of an unmanned transport device according to the present invention, with an open-bottomed pallet resting on the tines of the lifting forks, with the wheel arms vertically aligned with the tines of the lifting forks, and with the position of the lifting forks displaced laterally relative to the base unit of the transport device, aligning the pallet approximately flush with the lateral width limit of the base unit of the transport device for picking up or transferring the pallet without colliding with the lateral limiting surface. [Figure 4] FIG. 1 shows a bottom perspective view of an unmanned transport device according to the present invention, with the wheel arms vertically aligned with the tines of the lifting forks and the position of the lifting forks displaced laterally relative to the transport device base unit, aligning the pallet approximately flush with the lateral width limitations of the transport device base unit. [Diagram 5] 1 shows an unmanned transport device according to the present invention as viewed from below, with the bottom of the pallet closed in the left half and open in the right half, with the wheel arms spaced the widest in the left half and the wheel arms spaced the narrowest in the right half, resulting in the smallest possible turning circle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The unmanned transport device 1 according to the invention is used for the automatic, space-saving and collision-free picking up, lifting, transporting, raising and handing over of closed-bottom and open-bottom pallets 2. Transporting here means moving the pallets from any first point to any second point along an unlimited trajectory without the need for further devices.

[0034] The unmanned transport device 1 according to the present invention has a substantially U-shaped chassis with two legs formed as wheel arms 2, 2a which are laterally displaceable together or independently of one another in directions 2', 2a' relative to the base unit 8 of the transport device 1 or the lower part 10 of the base unit and which can be positioned in a first position aligned below in direction 2', 2a' and in a second position laterally in direction 2', 2a' spaced outwardly from the tines 4, 4a of the lifting forks.

[0035] Actively or passively steerable driven or non-driven wheels 3, 3a are provided in the front area on wheel arms 2, 2a which are connected at their rear ends to rear walls 9, 9a, respectively, which are mounted thereon in such a way that they are laterally displaceable relative to the base unit 8 or to the lower part 10 of the base unit and displaceable in the directions 2', 2a' by an electric, pneumatic, hydraulic or other actuating drive system, not shown in more detail. The claws 4, 4a of a lifting fork are connected to the rear wall 5 and form said lifting fork, which as a whole is laterally displaceable in the direction 5' relative to the base unit 8 or to the lower part 10 of the base unit.

[0036] In another particularly preferred embodiment variant, the claws 4, 4a of the lifting forks can be designed to be displaceable laterally 5' relative to the rear wall 5 or the base unit 8 or the lower part 10 of the base unit, independently of one another relative to the rear wall 5. By means of a lifting device, which consists, for example, of a lifting carriage 6 and a vertical guide 7, the lifting forks can be moved vertically in the direction 6'.

[0037] The vertical guide 7 may be a simple lifting mast or a telescopic guide arrangement, not shown in more detail, the lifting drive of said lifting arrangement may be, but is not limited to, electric, hydraulic or pneumatic, and the transmission of the lifting movement may be, but is also not limited to, by chain drive, belt drive, threaded spindle actuation or cylinder.

[0038] The base unit 8 contains the control system, communication, power supply, optical and acoustic signalling elements, safety devices, cameras, protective covers etc. The lower part 10 of the base unit is fixedly connected to the base unit 8 and to the vertical guide 7 and to the laterally displaceable rear wall parts 9, 9a of the wheel arms 2, 2a.

[0039] The drive system consists of at least one steerable drive unit 11 or 11a, which is mounted rotatably about a vertical axis 11″ or 11a″ and, in a particularly preferred embodiment, is also mounted so as to be horizontally tiltable about a horizontal axis 11′″ or 11a′″ and has at least one drive wheel 12 or 12a rotatable about a rotation axis 11′ or 11a′, preferably each drive unit 11 or 11a is designed with two drive wheels 12 or 12a, the rotation speed and direction of which can be changed independently of each other. Thereby, by means of at least one of the drive units 11, 11a and / or the wheels 3, 3a (rotatable about a horizontal axis 3′, 3a′ and about a vertical axis 3″, 3a″), the transport device can be moved along any desired trajectory.

[0040] The unmanned transport device 1 of the present invention is designed to be particularly compact, and the rotation circle generated when rotating in a stationary state is small, and the diameter of the rotation circle 100 is approximately 60% larger than the diagonal of a standard pallet when the wheel arms 2, 2a are positioned farthest outward and a closed-bottom pallet 21 is used as the transported item, and the diameter of the rotation circle 100' is approximately 40% larger than the diagonal of a standard pallet when the wheel arms 2, 2a are positioned farthest outward and a pallet 22 with an open bottom is used as the transported item.

[0041] The arrangement of the drive units 11, 11a directly below the base unit 8 and the wheels 3, 3a in the front end area of ​​the wheel arms 2, 2a has the effect that the centre of gravity of the transport device according to the invention is always located in the area between the drive units 11, 11a and the wheels 3, 3a in both the unloaded and loaded state (e.g. in accordance with standards according to ISO 8611), resulting in a permanent tilt-stable state, no need for stabilising counterweights, a very low self-weight below the intended maximum load, low energy consumption and low floor load.

[0042] The lifting forks 4, 4a, the wheel arms 2, 2a, the base unit 8, etc. are provided with sensors for safety monitoring, obstacle detection, human detection, pallet orientation detection, environmental detection, etc.

[0043] The unlimited maneuverability and lateral adjustment of the lifting forks 4, 4a and wheel arms 2, 2a so that the transport pallet 22 is aligned with at least the maximum lateral width 8' of the base unit 8 or the lower part 10 of the base unit allows the pallet 22 to be picked up or transferred approximately flush with an interface 30, such as the inner wall of a loaded container or other lateral interface.

[0044] By selectively controlling the drive units 11, 11a, the transport device can move in all directions, without any limitations, from any first point to any second point along any trajectory, including a curved trajectory with rotation at rest.

[0045] An open-bottom pallet 22, whose width is narrower than that of the transport device 1, can be picked up and placed, for example sideways and flush, on the inner wall or other lateral boundary surface 30 of a loaded container without collision.

[0046] For example, sensors may be integrated into the lifting forks 4, 4a, the wheel arms 2, 2a and / or the base unit 8 for safety monitoring, obstacle detection, pallet orientation detection and environmental detection.

[0047] The transport device 1 has a base unit 8, which has at least one of the following non-limiting group of elements, for example a control system, communication equipment, power supply, optical and / or acoustic signaling elements, safety devices, protective covers, cameras, etc.

[0048] The transport device 1 is designed compact and particularly lightweight without counterweights and requires a particularly small surface area. If the wheel arms 2, 2a are arranged at the outermost spacing and closed-bottom pallets 21 are used as transport material, the smallest possible rolling circle 100 when rolling at standstill is only approximately 60% larger than the diagonal of a standard pallet. If the wheel arms 2, 2a are arranged at the narrowest spacing and open-bottom pallets 22 are used as transport material, the diameter of the rolling circle 100' is only approximately 40% larger than the diagonal of a standard pallet.

[0049] The automated transport device according to the invention is particularly light, does not require counterweights, consumes as little energy as possible, requires minimal space and does not require any further equipment. [Explanation of symbols]

[0050] 1. Unmanned transport device according to the present invention 2,2a Wheel arm 2´,2a´ Transverse displacement direction of wheel arm 3,3a Wheel in wheel arm 3´,3a´ Wheel rotation axis 3´´,3a´´´ Vertical rotation axis of the wheel 4,4a Lifting fork claws 5 Rear wall of the lifting fork claws 5´ Transverse displacement direction of lifting fork 6 Lifting carriage 6´ Lifting carriage lift direction 7 Vertical Guide 8 Base Unit 8´ Maximum width of base unit or bottom of base unit 8´ 9,9a Rear end of wheel arm 10 Bottom of the base unit 11,11a Steerable drive unit 11', 11a' Rotation shaft of drive wheels 12, 12a 11´´,11a´´ Vertical rotation axis of drive unit 11´´´,11a´´´ Horizontal tilt axis of drive unit 12,12a Drive wheel 13,13a Wheel unit 21 Closed-bottom pallets 22 Open-bottom pallets 30 Lateral boundary surfaces (e.g. inner wall surfaces of containers) 100,100´ The rolling circle when the wheel arms are spaced most outward and when they are spaced the narrowest, respectively, while the vehicle is stationary.

Claims

1. An unmanned transport device (1) for automatically picking up, transporting, lifting, and transferring pallets with closed bottoms (21) and pallets with open bottoms (22) in a space-saving manner and without collisions, The chassis, which is U-shaped in plan view, comprises a base unit (8), two legs, a lifting device consisting of a lifting carriage (6) to which the claws (4, 4a) of a lifting fork are attached, and a vertical guide (7), The two legs of the U-shaped chassis are Designed as a wheel arm (2, 2a) that is adjustable in the transverse direction, A transport device (1) characterized in that, in a first position, it can be positioned so as to be aligned below the claws (4, 4a) of the lifting fork, and in a second position, it can be positioned laterally along the width of the transport device, spaced outward from the claws (4, 4a) of the lifting fork.

2. The transport device (1) according to claim 1, characterized in that the wheel arms (2, 2a) are displaceable in the transverse direction together or independently of each other with respect to the base unit (8) of the transport device (1), or with respect to the lower part (10) of the base unit (8).

3. The transport device (1) according to claim 1 or 2, characterized in that the claws (4, 4a) of the lifting fork are fixedly connected to the rear wall portion (5).

4. The transport device (1) according to claim 3, characterized in that the rear wall portion (5) is displaceable in the transverse direction relative to the base unit (8) or the lower part (10) of the base unit (8).

5. The transport device (1) according to claim 1 or 2, characterized in that the claws (4, 4a) of the lifting fork are independently displaceable in the transverse direction.

6. The transport device (1) according to claim 1 or 2, characterized in that each of the wheel arms (2, 2a) has a steerable wheel unit (13, 13a).

7. The transport device (1) according to claim 1, characterized in that the base unit (8) comprises at least one operable drive unit (11, 11a).

8. The transport device (1) according to claim 7, characterized in that the operable drive unit (11, 11a) is mounted so as to be rotatable about a vertical axis (11'' or 11a'') and so as to be tiltable about a horizontal axis (11'' or 11a'').

9. The transport device (1) according to claim 7 or 8, characterized in that the operable drive unit (11, 11a) comprises two independently driven drive wheels (12 or 12a).

10. The transport device (1) according to claim 1 or 2, characterized in that the vertical guide (7) of the lifting device is a simple lifting mast or a telescopic guide device, the lifting drive of the lifting device is performed electrically, hydraulically, or pneumatically, and the transmission of the lifting motion is performed by a chain drive, belt drive, threaded spindle drive, or cylinder.

11. The transport device (1) according to claim 1 or 2, characterized in that the wheel arm (2, 2a) is displaceable in the transverse direction beyond the width of the base unit (8).

12. A method for operating pallets (21, 22), wherein the unmanned transport device (1) described in claim 1 performs any of the following sequence of operations. In the case of the pallet (22) with an open bottom, the transport device (1) moves the two legs of the U-shaped chassis, together with the claws (4, 4a) of the lifting fork attached to the U-shaped chassis, to the bottom of the pallet (22), raises the claws (4, 4a) of the lifting fork, and moves the bottom of the pallet (22). In the case of a pallet (21) with a closed bottom, the transport device (1) displaces the legs of the U-shaped chassis laterally outward, moves the legs to the side of the pallet (21), engages the claws (4, 4a) of the lifting forks with the underside of the pallet (21), and then moves the claws (4, 4a) of the lifting forks up and down to move the pallet (21).

13. The method according to claim 12, characterized in that when the pallets (21, 22) rise, the legs of the U-shaped chassis are displaced laterally inward below the pallets (21, 22).

14. The method according to claim 12 or 13, characterized in that the claws (4, 4a) of the lifting fork are displaced laterally.

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