DEVICE FOR PICKING UP PALLETS

Abstract

 Pallet lifting device comprising a mobile lifting element for pallets, said lifting element comprising at least one hook system for pallets, and at least one guide that allows the vertical movement of the mobile element, the device comprising a pallet support base, the pallet support base and the mobile lifting element being able to move in relation to one another in such a way that they can be in a first position in which the base is vertically under the mobile element, and in a second position in which the pallet support base is outside the vertical plane of the mobile element.

Description

[0001] A forklift is usually used to pick up pallets, which is a device that includes a lifting element with two elongated protruding claws that protrude horizontally and are vertically mobile. The forklift stands close to the pallet, places the claws towards their lower position until they are located at the height of the bottom of the pallet and advances so that the claws are located below the pallet. The claws are then raised, lifting the pallet and allowing it to be transported through the plant to a storage point. The unloading operation requires a reverse operation of the loading operation. A problem associated with this type of device is that the protrusions of the forklift protrude substantially which entails a risk of accidents in the plant when the forklift moves through it. In addition, the forklift can only lift a single pallet, or a set of previously stacked and secured pallets.

[0002] Often times, the use of a forklift in a plant implies delimiting a circuit in the plant itself for the forklift, as well as delimiting areas in the plant for the passage of people between the lines of said circuit, limiting the element layout options within the plant.

[0003] The object of the present invention is to provide a pallet lifting device that does not have the aforementioned drawbacks.

[0004] More particularly, the present invention discloses a pallet lifting device comprising a mobile lifting element for pallets, said lifting element comprising at least one hook system for an external element, preferably for a pallet, and at least one guide that allows the vertical movement of the mobile element, with the particularity that the device comprises a pallet support base, the pallet support base and the mobile lifting element being able to move in relation to one another in such a way that they can be in a first position in which the base is vertically under the mobile element, and in a second position in which the pallet support base is outside the vertical plane of the mobile element.

[0005] By not including protrusions that protrude substantially, the device disclosed in the present invention has the advantage that it allows working safely, significantly reducing the possibility of accidents in the factory. Another advantage of the present invention is that the device allows pallets to be picked up anywhere on the work plant, without the need to previously stack the pallets before picking them up, which, in turn, implies greater flexibility in the layout of elements on the work plant.

[0006] Another advantage of the present invention is that there is no need to anchor objects or lifting means to the ground, improving flexibility in plant layout, more specifically a device for picking up pallets at ground level, another object of the invention being to provide a device that allows improved safety in said plant.

[0007] Preferably, the lifting element comprises at least two hook systems and at least two vertical guides, said at least two hook systems being located opposite to each other. More preferably, said at least two vertical guides are located in such a way that they allow the vertical movement of each of the at least two hook systems.

[0008] Preferably, the lifting element comprises at least four hook systems, located in two pairs of hook systems, each pair of hook systems being located opposite to each other. More preferably, each of the at least two vertical guides are located in such a way as to allow vertical movement of each of the at least two pairs of hook systems. Preferably, the mobile lifting element for pallets comprises a connecting guide located horizontally, said guide mechanically connecting the hook systems opposite to each other, so that the hook systems opposite to each other can approach and/or move away from each other, allowing hooking a pallet located between said systems or pairs of systems by opposite sides of the pallet. More preferably, said guide comprises a piston.

[0009] Preferably, the hook systems are connected to the connecting guide by means of at least one transmission element. More preferably, the transmission element is made up of an element with a generally triangular shape and an element or stop with a generally rectangular shape. More preferably, the mobile lifting element for pallets comprises at least one stop. Even more preferably, said stop is the transmission element.

[0010] Preferably, the hook system are claws adapted for fastening pallets. These claws allow to properly hook a pallet. Alternatively, the hook system comprises other types of hooks of known type, such as magnets.

[0011] Preferably, the base is mobile in a direction perpendicular to the movement of the mobile element. More preferably, the base is mobile in a direction perpendicular to that of the movement of the mobile element, and perpendicular to the direction of movement of the hook systems.

[0012] Preferably, the device comprises a device stabilizing element, said stabilizing element being a retractable element. More preferably, the stabilizing element of the device consists in retractable wheels. Even more preferably, the wheels comprise a guide, preferably a vertical guide. This stabilizing element extends or retracts to facilitate stabilizing the device when the pallet support base and the mobile pallet lifting element are arranged in the second relative position described above, in which the pallet support base is outside the vertical plane of the mobile element.

[0013] Preferably, the device is a mobile device. More preferably, the device is an autonomous mobile robot (AMR), said device comprising an autonomous navigation system. Preferably, the autonomous navigation system is a system controlled by control software, in such a way that it allows the device to move following a predetermined path, or remotely controlled by an operator. An advantage of this navigation system is that it allows the device to move autonomously without the need for an operator to drive the device directly. Alternatively, the navigation system may be a sensor-based navigation system or any other known type.

[0014] Preferably, the device comprises a casing, the lifting element being located inside said casing, and the pallet support base being located below said casing. More preferably, the casing is generally rectangular in shape. Even more preferably, the casing comprises at least one central portion and two lateral portions. Preferably, the distance between both lateral portions is greater than the width of a pallet, the at least two hook systems being located on said lateral portions opposite to each other. Preferably, the second relative position between the base and the mobile lifting element is a position in which the base is located on the opposite side of the central portion of the casing in which the pallet is intended to be placed.

[0015] In addition, the device of the present invention can carry out the following sequential steps to pick up pallets:

• placing a pallet lifting device close to a pallet,
• moving the device's pallet support base away from the vertical plane of the device's mobile lifting element,
• lowering the pallet hook system of the mobile lifting element until it is located below the pallet to be picked up,
• moving the at least one hook system horizontally until it is located below the top of the pallet to be picked up,
• raising the pallet hook system vertically until the pallet rises above the base,
• moving the device's pallet support base to the first position in which the base is vertically under the mobile element,
• moving the at least one hook system horizontally in the opposite direction to the pallet, placing the pallet on the base.

[0016] More preferably, the following operation to pick up pallets comprises the additional steps of:

• extending the stabilizing system until said stabilizing system is in contact with the ground, before moving the device's pallet support base out of the vertical plane of the device's mobile lifting element, and
• retracting the stabilizing system after placing the pallet on the base.

[0017] For better understanding, drawings of an embodiment of the device for picking up pallets, the object of the present invention, are attached by way of non-limiting example.

Fig. 1 shows a perspective view of a device for picking up pallets according to an embodiment of the present invention.

Fig. 2 shows a perspective view of the device with the stabilizing element of the device extended.

Fig. 3 shows a first perspective view of the device with the stabilizing element of the device extended, the base and the lifting element located in the second position in relation to one another.

Fig. 4 shows a second perspective view of the device of Fig. 3.

Fig. 5 shows a top view of the device of Figs. 3 and 4.

Fig. 6 shows a lifting view of the device before picking up a pallet, with the hook systems in the upper position.

Fig. 7 shows a lifting view of the device before picking up a pallet, the hook systems in the lower position.

Fig. 8 shows a lifting view of the device after picking up a pallet, with the hook systems in the lower position.

Fig. 9 shows a perspective view of the device after picking up a pallet, with the stabilizing element of the device extended.

Fig. 10 shows a perspective view of the device after picking up a pallet, with the stabilizing element of the device retracted.

[0018] Figs. 1 to 10 show an embodiment of a pallet lifting device 10. The device 10 comprises a mobile lifting element 4 for pallets and a pallet support base 2. The device also comprises a casing 1. The lifting element is located inside said casing 1. The base 2 is located below said casing 1. Fig. 1 shows a generally rectangular casing, adapted for picking up rectangular pallets. The casing 1 comprises a central portion and two lateral portions, with dimensions such that they allow a pallet to be housed between both lateral portions.

[0019] The lifting element 4 of the exemplary embodiment comprises at least one hook system 41 for pallets, and a guide 44 that allows the vertical movement of the mobile element. More specifically, in the example, the lifting element 4 comprises four hook systems 41. Said four hook systems 41 are located in two pairs of hook systems 41. Each pair is located opposite the other pair so that, as the pairs of systems approach each other, the lifting element 4 allows hooking to both sides of a pallet. The two hook systems 41 are shown on respective opposite lateral portions of the casing 1. This hook system is shown as claws although other types of hook systems are also possible. Alternatively, the hook system may be a hook system adapted to another type of external element other than a pallet.

[0020] Both pairs of hook systems 41 are connected together by a guide 45 located horizontally, allowing both hook systems 41 to move away from and/or approach each other. The guide 45 shown in Fig. 2 comprises a piston, although any horizontal guide of known type may be used. In addition, the mobile lifting element 4 for pallets additionally comprises transmission elements or handles that allow the movement of the guides 44 and 45 to be transmitted to the hook system 41. In the embodiment disclosed, the lifting element 4 comprises two transmission elements, one for each hook system 41. This transmission element is shown formed, in this example, by an element 42 of a generally triangular shape and an element or stop 43 of a generally rectangular shape. The triangular shape of the element 42 is intended to improve the tensile strength and rigidity of the pallet lifting element 41, although other shapes are also possible. The transmission elements 42, 43 also delimit the position of a pallet on the base 2 after its pick-up and facilitate its placement on said base 2.

[0021] The mobile lifting element 4 for pallets is located on the inside of the central and lateral portions of the casing. The pairs of hook systems 41 and the transmission element 42 are located inside the lateral portions of the casing, both pairs of systems being opposite to each other. The stop 43 is located in the inner part of the central portion (the concept of inner part being defined as the area outside the casing closest to the pallet pick-up area, delimited by the lateral and central portions of the casing).

[0022] The pallet support base 2 and the mobile lifting element are able to move in relation to one another in such a way that they can be in a first position in which the base 2 is vertically under the mobile element (shown in Fig. 2, for example), and in a second position in which the pallet support base 2 is outside the vertical plane of the mobile element (shown in Fig. 3, for example). In the example shown, the base 2 for pallets comprises a guide 21 that facilitates its horizontal movement in the two positions described above, the second position being a position in which the base 2 is located on the opposite side of the central portion of the casing 1 in which the pallet is intended to be placed.

[0023] The device 1 also comprises a stabilizing support. In the exemplary embodiment of Figs. 1 to 10, this support are stabilizer wheels 3. These wheels 3 facilitate the balance of the device 1 when the base 2 and the mobile element are in the second position in which the pallet support base 2 is outside the vertical plane of the mobile element. In the example, the stabilizing wheels 3 are retractable. In the exemplary embodiment shown, the device has two wheels 3, each located in respective guides 31 to allow contact of the wheels 3 with the ground. Other known wheel extension and retraction systems are also possible. Guides 31 are shown located on the lateral portions of the casing.

[0024] Fig. 1 shows the wheels retracted, arranged in a raised position with respect to the ground, and located on the outside of the lateral portions of the casing 1, that is, at the opposite end of the central portion of the device.

[0025] Other configurations and positions of the wheels on the device are also possible.

[0026] In Fig. 2, the wheels 3 are shown extended as the guides 31 move, so that the wheels 3 are in contact with the ground. This gives the device 1 more stability when the pallet support base 2 is moved to its second position.

[0027] Figs. 3, 4, and 5 show the base 2 in the second position, from different points of view. As can be seen, in this second position, the mobile lifting element has freedom of movement so that the pallet hook systems 41, located on both sides of the lateral portions of the casing, can move vertically at ground level to hook a pallet 9 located between both lateral portions of the casing.

[0028] The hook system can also lift several pallets 9 previously placed one on top of the other.

[0029] Alternatively, the pallet may not be located on the ground but on top of a platform, another pallet or any external element. In this case, the pallet lifting element will move vertically until the hook system is located below the pallet to be picked up, without touching the ground.

[0030] Figs. 6 to 10 show the pallet pick-up operation of the example device. Once the wheels 3 have been extended and the base 2 has been moved so that it is outside the vertical plane of the vertical movement of the pallet lifting element (Fig. 6), the pallet hook system 41 lowers until it is located at a suitable height to pick up the pallet. Subsequently, the hook systems 41 move towards the pallet so that it is located below the upper part of the pallet, as shown in Fig. 7 (i.e., having two pairs of hook systems, both pairs approach each other while closing). The stops 43 of the lifting element facilitate the positioning of the pallet 9 and prevent the pallet from falling during its lifting. Then, with the hook system closed, the lifting element rises vertically so that the pallet is raised with respect to the ground, as seen in Fig. 8. More specifically, the lifting element raises the pallet above the base located on the opposite side of the central portion of the casing.

[0031] With the pallet 9 raised above the base 2, the base 2 moves horizontally to its first position, in which it remains vertically under the mobile lifting element. Next, the pairs of hook systems 41 of the lifting element are separated, that is, the pairs of hook systems 41 move towards the respective lateral portions of the casing, dropping the pallet on top of the support base 2, as shown in Fig. 9. The pallet is also held laterally by the transmission elements 42, 43 that act as stops, and underneath by the guides 21 of the base 2 of the device 1.

[0032] Finally, and with the pallet 9 already placed on the base 2, the stabilizing wheels 3 retract. In this way, the device 10 can move around the plant to pick up a new pallet.

[0033] When it is necessary to pick up a pallet when the device already has a pallet located above the base 2, the pick-up process will be similar to that described, with the first pallet being moved together with the base 2 towards the second position of the base, the second pallet being raised in the manner already described, to later return the base 2 to its initial position and drop the second pallet already raised on top of the first pallet.

[0034] In addition, the device may comprise an autonomous navigation system to move around the factory or plant.

[0035] The device 10 shown in the figures is also shown with a signal 12 that allows workers to easily identify the device when it is moving around the plant. This signal, which can be a light signal of the LED type or similar, as well as any type of signal, is shown in the figures located on a projection of the device placed in such a way that the signal is located above the body 1 of the device. Thus, this signal 12 makes it possible to avoid incidents and accidents in the factory due to a possible collision of an operator or another device with the device 10.

[0036] Although the invention was presented and described with reference to one embodiment of the same, it will be understood that this is not a limitation of the invention, since a person skilled in the art, when interpreting the subject matter disclosed in this specification, claims, and drawings, may find multiple other constructive details to implement it. Thus, all variants and equivalents will be included within the scope of the present invention if they can be considered as falling within the broader scope of the following claims.

Claims

1. Pallet lifting device comprising a mobile lifting element for pallets, said lifting element comprising at least one hook system for pallets, and at least one guide that allows the vertical movement of the mobile element, characterized in that the device comprises a pallet support base, the pallet support base and the mobile lifting element being able to move in relation to one another in such a way that they can be in a first position in which the base is vertically under the mobile element, and in a second position in which the pallet support base is outside the vertical plane of the mobile element.

2. Device, according to claim 1, characterized in that the lifting element comprises at least two hook systems and at least two vertical guides, said at least two hook systems being located opposite to each other.

3. Device, according to claim 2, characterized in that the lifting element comprises at least four hook systems, located in two pairs of hook systems, each pair of hook systems being located opposite to each other.

4. Device according to any of claims 2 to 3, characterized in that the mobile lifting element for pallets comprises a connector guide located horizontally, said guide mechanically connecting the opposing hook systems to each other, so that the hook systems opposite to each other can approach and/or move away from each other, allowing a pallet located between said systems or pairs of systems to be hooked by opposite sides of the pallet.

5. Device, according to claim 4, characterized in that the hook systems are connected to the connector guide by means of at least one transmission element.

6. Device, according to any of the preceding claims, characterized in that the at least one hook system is a claw adapted for fastening pallets.

7. Device, according to any of the preceding claims, characterized in that the base is mobile in a direction perpendicular to the movement of the mobile element.

8. Device, according to claim 7, characterized in that the base is mobile in a direction perpendicular to the movement of the mobile element and perpendicular to the direction of movement of the hook systems.

9. Device, according to any of the preceding claims, characterized in that it comprises a device stabilizing element, said stabilizing element being a retractable element.

10. Device, according to claim 9, characterized in that the stabilizing element of the device are retractable wheels.

11. Device, according to any of the preceding claims, characterized in that the device is an autonomous mobile robot, said device comprising an autonomous navigation system.

12. Device, according to any of the preceding claims, characterized in that the device comprises a casing, wherein the lifting element is located inside said casing, and the pallet support base is located below said casing.

13. Device, according to claims 2 and 12, characterized in that the casing has a generally rectangular shape, the casing comprising at least one central portion and two lateral portions, the distance between both lateral portions being greater than the width of a pallet, the at least two hook systems being located on said lateral portions opposite to each other.

14. Method for picking up pallets that comprises the following sequential steps:

- placing a pallet lifting device according to any of claims 1 to 13 close to a pallet,

- moving the device's pallet support base away from the vertical plane of the device's mobile lifting element,

- lowering the pallet hook system of the mobile lifting element until it is located below the pallet to be picked up,

- moving the at least one hook system horizontally until it is located below the top of the pallet to be picked up,

- raising the pallet hook system vertically until the pallet rises above the base,

- moving the device's pallet support base to the first position in which the base is vertically under the mobile element,

- moving the at least one hook system horizontally in the opposite direction to the pallet, placing the pallet on the base.

15. Method, according to claim 14, characterized in that it comprises the additional steps of:

- extending the stabilizing system until said stabilizing system is in contact with the ground, before moving the device's pallet support base out of the vertical plane of the device's mobile lifting element, and

- retracting the stabilizing system after placing the pallet on the base.

Drawing