Lifting vehicle for lifting and longitudinally shifting loads to be transported

Abstract

Lifting vehicle (2) for lifting and transporting loads (4), comprising a vehicle frame (6), a chassis (8) adjacent to a ground plane (BE), which is designed to move the lifting vehicle (2) in a direction of travel (FR) and has at least one front wheel (10) rotatably mounted about a front wheel rotation axis (RA1) and at least one rear wheel (12) rotatably mounted about a rear wheel rotation axis (RA2), which is oriented at right angles to the direction of travel (FR) and parallel to the front wheel rotation axis (RA1), at least in a straight-ahead position of the chassis (8), and arranged downstream of the front wheel (10) in the direction of travel (FR), and a load movement device (14) comprising a lifting device (16) having at least one support element (18) and designed to move the support element (18) relative to the vehicle frame (6) from a first lifting position into a lifting direction (HR) away from the ground plane (BE) into a second lifting position, characterized by in that the load movement device (14) comprises a displacement device (20) which is designed for a translational movement of at least the support element (18) relative to the vehicle frame (6) from the second lifting position into a displacement direction (VR) which is oriented at an angle to the lifting direction (HR) and at least partially opposite to the direction of travel (FR).

Description

[0001] The invention relates to a lifting vehicle for lifting and transporting loads. The lifting vehicle has a vehicle frame, a chassis, and a load-moving device. The chassis is adjacent to a ground plane. The chassis is designed to move the lifting vehicle in a direction of travel. The chassis has at least one front wheel, which is rotatably mounted about a front-wheel rotation axis. The chassis also has at least one rear wheel, which is rotatably mounted about a rear-wheel rotation axis. The rear-wheel rotation axis is aligned at right angles to the direction of travel and parallel to the front-wheel rotation axis, at least when the chassis is in a straight-ahead position. The rear wheel is arranged downstream of the front wheel in the direction of travel. The load-moving device comprises a lifting device. The lifting device has at least one support element. The lifting device is designed to move the support element relative to the vehicle frame.The support element is movable from a first lifting position into a lifting direction away from the ground level into a second lifting position.

[0002] Such a lifting vehicle is known, for example, as a forklift truck or stacker truck and is generally used for internal goods handling, in particular for storing and retrieving goods and for loading them.

[0003] There are different types of lifting vehicles of this type, each of which has significant disadvantages. On the one hand, there are typical forklift trucks whose carrying element is arranged completely offset in the direction of travel from the front wheel in the first lifting position. If the carrying element of such forklift trucks is moved in the direction of travel into or under a load to be lifted and then moved from the first lifting position to the second lifting position to lift the load, the center of gravity of the total weight carried by the chassis of the lifting vehicle shifts in the direction of travel. Depending on the weight of the load, this shift in the center of gravity leads to instability and, in particular, to poor handling of the lifting vehicle. On the other hand, side-loading or cross-loading reach trucks are known. On these, two front wheels are arranged laterally offset from the carrying element. This does reduce instability.However, the position of the front wheels prevents the pickup of loads whose width near the ground exceeds the distance between the front wheels, as is often the case with building materials.

[0004] The object of the present invention is to provide a lifting vehicle of the type described above, by means of which the disadvantages described above can be avoided and loads of any size can be reliably lifted and transported.

[0005] According to the invention, the load movement device comprises a displacement device. The displacement device is designed for a translational movement of at least the support element relative to the vehicle frame from the second lifting position into a displacement direction into a displacement position. The displacement direction is oriented at an angle to the lifting direction and at least partially opposite to the direction of travel.

[0006] The lifting vehicle according to the invention is an industrial truck, in particular a lift truck, forklift truck, or pallet truck. The lifting vehicle according to the invention comprises, in particular but not necessarily, a driver's cab and a drive for the chassis.

[0007] The chassis preferably has two front wheels. The chassis preferably has one steerable rear wheel or two steerable rear wheels. Alternatively or additionally, the lifting vehicle is designed as an articulated vehicle with a front carriage comprising the two front wheels and a rear carriage comprising two rear wheels, which can pivot relative to the front carriage about an articulated steering axis perpendicular to the ground plane. The commercial vehicle is in the straight-ahead position when rotation of the wheels is accompanied exclusively by a translational movement of the vehicle frame, and / or at least one rear wheel is particularly preferably not steered. To guide the support element into or beneath a load to be lifted, the lifting vehicle must be moved in particular in the direction of travel. The direction of travel is aligned parallel to the ground plane on which the aforementioned wheels roll during operation.

[0008] The support element is designed in particular as a forklift tine that is configured for insertion into the hollow spaces of pallets. In this case, the lifting vehicle preferably has at least two laterally offset support elements. As an alternative to the forklift tine, the support element can be designed, for example, as a tapered tine, as a shovel, or other load-bearing element. The support element can be viewed as both a component of the lifting device and a component of the displacement device, or as an element that is merely moved by them but not necessarily included. In the first lifting position, the support element is preferably positioned offset in the direction of travel relative to at least one front wheel, as in a typical forklift truck.

[0009] The lifting device preferably comprises a lifting mast extending elongately in the lifting direction and in particular a hydraulic cylinder, a spindle, a lifting lever and / or a pulley block. A pulley block is understood above and below to mean a mechanical aid with a flexible tension element guided around at least one deflection wheel / roller. The tension element can also be part of the lifting vehicle according to the invention, without the deflection wheel / roller, which serves to lift the support element. The tension element is in particular a link chain, a rope or a belt such as a toothed belt. In particular, the pulley block effects a gear ratio such that the amount of force required to lift the support element is reduced. The lifting direction is preferably oriented perpendicular to the ground plane, at least in a first lifting device configuration.Preferably, the lifting device is designed such that the movement of the support element from the first lifting position to the second lifting position takes place in a translational manner.

[0010] The shifting device allows the load-bearing element to be shifted toward the center of the lifting vehicle after it has already been lifted. This shift also shifts the center of gravity of the total weight carried by the chassis against the direction of travel, after the center of gravity had shifted in the direction of travel during lifting. The shifting device therefore enables improved stability and handling compared to typical forklift trucks. This can be achieved without imposing size restrictions on the loads to be lifted, as is the case with side-loading forklifts, for example.With the lifting vehicle according to the invention, the support element is moved away from the ground level, in particular in the lifting direction into the second lifting position, to such an extent that a laterally projecting load is moved over the at least one front wheel during the subsequent displacement in the displacement direction. In particular, the displacement position is characterized in that the support element is at a smaller distance from the at least one rear wheel in this position than in the second lifting position.

[0011] The displacement direction is to be regarded as a vector resulting from a first vector oriented opposite to the direction of travel and a second vector at right angles thereto. The displacement direction is angled by at least 90°, preferably by at least 150° to the direction of travel. Particularly preferably, the displacement direction is oriented parallel to the ground plane, at least in a first displacement device configuration. In particular, the displacement direction is opposite to the direction of travel, i.e. pivoted by 180° thereto. In an alternative preferred embodiment of the lifting vehicle according to the invention, the displacement direction and the direction of travel are in the same direction. Particularly preferably, what is described above / below with reference to the front wheel then applies, at least in part, to the rear wheel and vice versa.

[0012] The vehicle frame is to be understood in particular as a rigid framework on which the chassis and the load-handling device are mounted. If the lifting vehicle according to the invention is designed as a pallet truck, only the physical axles of the wheels can form the vehicle frame. The aforementioned front wheel rotation axis and rear wheel rotation axis, on the other hand, are to be understood as geometric axes.

[0013] Preferably, the displacement device is designed such that the support element, in the displacement position, is arranged at least partially between a front wheel rotation axis plane and a rear wheel rotation axis plane. The front wheel rotation axis plane is arranged perpendicular to the ground plane. The front wheel rotation axis lies in the front wheel rotation axis plane. The rear wheel rotation axis plane is also arranged perpendicular to the ground plane. The rear wheel rotation axis lies in the rear wheel rotation axis plane. This applies at least when the chassis is in the straight-ahead position. In particular, the front wheel rotation axis plane intersects the support element in the displacement position. This is not the case in the second lifting position.The above design of the shifting device allows the achievement of sufficient stability of the loaded lifting vehicle without leading to an impractical installation space requirement, in particular to an excessive length, of the lifting vehicle.

[0014] The displacement device preferably has at least one displacement carriage and at least one displacement guide rail for guiding the guide carriage in the displacement direction. The displacement guide rail extends, in particular, longitudinally in the displacement direction. The displacement guide rail is, in particular, arranged stationary relative to the vehicle frame. The displacement guide rail is preferably L- or U-shaped in a section perpendicular to the displacement direction. Particularly preferably, the displacement device has two displacement guide rails arranged mirror-symmetrically to one another. The prescribed design results in a particularly high load-bearing capacity of the displacement device.

[0015] The sliding carriage preferably has at least one carriage wheel designed to roll along the sliding guide rail. A rolling axis of the carriage wheel is aligned, in particular, parallel to the front wheel rotation axis. Particularly preferably, the sliding carriage has at least two carriage wheels per sliding guide rail to prevent unintentional tilting of the carriage.

[0016] As an alternative to at least one carriage wheel, the sliding carriage and the sliding guide rail preferably form a sliding bearing. Specifically, the sliding bearing is formed, in particular, by a rail guide or a plastic block bearing.

[0017] The displacement device is preferably designed such that a distance over which the support element can be moved from the second lifting position in the displacement direction into the displacement position corresponds to at least 10%, preferably at least 30%, particularly preferably at least 50% of the distance between the rear wheel rotation axis and the front wheel rotation axis parallel thereto. This distance is preferably smaller than the distance over which the lifting device can move the support element away from the ground plane.

[0018] Preferably, at least a first part of a lifting guide rail encompassed by the lifting device is arranged on the sliding carriage for guiding a lifting carriage of the lifting device in the lifting direction. The lifting guide rail is encompassed in particular by the lifting mast. The lifting guide rail preferably extends longitudinally in the lifting direction. With the lifting guide rail and the lifting carriage, the lifting device is constructed in particular in the same way as the lifting device of conventional forklift trucks. The lifting carriage, like the sliding carriage, has at least two carriage wheels. As an alternative to the carriage wheels, the lifting carriage and the lifting guide rail preferably form a sliding bearing. In detail, the sliding bearing is designed in particular by a rail guide or a plastic block bearing. The support element is preferably mounted on the lifting carriage immovably or in a pivoting or rotatable manner.The first part of the lifting guide rail and / or the lifting carriage are / is preferably arranged completely between the aforementioned wheel rotation axis planes in the shifting position. Because part of the lifting guide rail is arranged on the shifting carriage, the shifting device of the lifting vehicle according to the invention can be easily combined with the proven design of known forklift trucks.

[0019] Particularly preferably, the first part of the lifting guide rail is mounted so as to be pivotable relative to the sliding carriage about a rotational axis. The rotational axis lies in particular in a plane perpendicular to the floor plane and parallel to the direction of travel. The rotational axis is preferably oriented perpendicular to the floor plane or parallel to the direction of travel. The axis is fixed relative to the sliding carriage. This pivotal mobility allows loads to be optimally made available for further use after the support element has been transferred into the sliding position, in particular by transferring them laterally or tipping them over.

[0020] The lifting guide rail preferably has a second part. The second part is closer to the ground level than the first part, at least when the support element is arranged in the second lifting position. The second part of the lifting guide rail is preferably mounted on the vehicle frame. In a lifting configuration of the lifting guide rail in which the support element is to be moved from the first lifting position to the second lifting position, the lifting carriage runs, in particular, seamlessly from the first part into the second part of the lifting guide rail. In contrast to the first part, the second part of the lifting guide rail is not mounted on the sliding carriage, since, in order to enable the support element to be lowered far, it comes so close to the ground level that it would collide with the vehicle frame if moved in the sliding direction.If the lifting guide rail does not reach that close to the floor level, it is preferably designed as a single piece and mounted entirely on the sliding carriage.

[0021] Preferably, the second part of the lifting guide rail is pivotally mounted relative to the vehicle frame about a pivot axis that is parallel to the ground plane and perpendicular to the direction of travel. Alternatively or additionally, the part of the lifting guide rail arranged on the sliding carriage is pivotally mounted relative to the sliding carriage about a pivot axis. Due to the pivotal mobility, a lifted load can be tilted toward the center of the vehicle to safely prevent the load from accidentally falling. In particular, the lifting vehicle has a release device that only enables movement of the support element from the first lifting position to the second lifting position when the second part of the lifting guide rail is aligned with the first part of the lifting guide rail.As an alternative to the prescribed structure, it is possible according to the invention to arrange at least part of the sliding guide rail on the lifting carriage, so that the part with the support element can be transferred from the first lifting position to the second lifting position.

[0022] The displacement device preferably has a drive motor. In particular, this is a hydraulic motor or an electric motor. Alternatively or additionally, the displacement device preferably comprises a hydraulic cylinder, a spindle, a displacement lever, and / or a pulley. The drive motor causes the support element to move from the second lifting position in the displacement direction. The drive motor enables, in particular, a continuous movement of the support element between the second lifting position and the displacement position.

[0023] Preferably, the lifting device is designed to move the support element relative to the vehicle frame from the second lifting position into the lifting direction away from the ground level into a third lifting position. Particularly preferably, the lifting device is also designed to move the support element relative to the vehicle frame from the displacement position into the lifting direction away from the ground level. The lifting vehicle according to the invention thus provides the greatest possible degrees of freedom for moving the loads.

[0024] In an advantageous embodiment of the lifting vehicle according to the invention, it has at least one support element which, before being moved from a support position relative to the vehicle frame into a travel position away from the ground level, is mounted. In the support position, the support element borders the ground level with a support surface. The support surface is further spaced from the rear wheel rotation axis than the front wheel rotation axis. The support element is preferably automatically transferred into the support position when the support element executes a specific movement or assumes a position, in particular when it is lifted from the first lifting position. In the support position, the support element is arranged in particular between the front wheel and the support element in the first lifting position. The support element serves to increase stability when the support element moves from the first lifting position to the second lifting position or to increase the maximum load that can be lifted.The support element is pivotally mounted on the vehicle frame and can be moved from the support position to the travel position and back by a hydraulic cylinder. Alternatively or additionally, the lifting vehicle has a spindle, an automatically or manually locking locking arrangement, or the like for moving the support element or for securing it in the support position.

[0025] In a first preferred variant of the lifting vehicle according to the invention, the at least one front wheel and the at least one rear wheel are directly adjacent to the ground. In a second preferred variant of the lifting vehicle according to the invention, the chassis is designed as a crawler chassis with a track element, also referred to as a chain, encircling the front and rear wheels. This allows for greater stability and soil protection.

[0026] The lifting vehicle preferably has a driver's cab. The driver's cab is characterized by a driver's seat, a standing area, a driver's cabin, and / or means for operating the lifting vehicle. The displacement device is particularly preferably arranged upstream of the driver's cab in the direction of travel. Alternatively, the displacement device is arranged downstream of the driver's cab in the direction of travel. In this case, the lifting vehicle in particular has a towed load movement device. In an advantageous embodiment of the invention, the driver's cab is movable relative to the vehicle frame from a first travel position to a second travel position. In particular, the driver's cab is pivotally mounted relative to the vehicle frame, preferably about a vertical pivot axis.With the driver's cab in the second travel position, the lifting vehicle has, in particular, a (main) direction of travel that is opposite to the (main) direction of travel of the lifting vehicle with the driver's cab in the first travel position. In particular, the driver's cab is positioned at the same height as the shifting device and, in a side view, above the rear wheel or the front wheel. However, the lifting vehicle can also be advantageously designed without the driver's cab. In particular, it is then a remote-controlled vehicle or a vehicle that can be operated on foot like a pallet truck.

[0027] Further details and advantages of the invention can be seen from the schematically illustrated and described embodiment below; they show: Fig. 1 a side view of a lifting vehicle according to the invention with a support element in a first lifting position, Fig. 2 the side view according to Fig. 1 with the support element in a tilted position, Fig. 3 the side view according to Fig. 1 with the support element in a second lifting position, Fig. 4 the side view according to Fig. 1 with the support element in a sliding position, Fig. 5 the side view according to Fig. 1 with a load carried by the supporting element, Fig. 6 the side view according to Fig. 4 with the load carried by the supporting element.

[0028] The features described below can also lead to further developments according to the invention, either individually or in combinations other than those shown. Identical or similarly functioning components of the exemplary embodiment are provided with identical reference numerals.

[0029] The figures show an embodiment of a lifting vehicle 2 according to the invention. The lifting vehicle 2 has a vehicle frame 6 and a chassis 8. The chassis 8 comprises two front wheels 10 and two rear wheels 12, each of which is adjacent to a ground plane BE.

[0030] The chassis 8 is shown in a straight-ahead position. In this position, the lifting vehicle 2 is configured for a translational movement of the vehicle frame 6 in a direction of travel FR. The two front wheels 10 are rotatable about a front wheel rotation axis RA1, and the two rear wheels 12 are rotatable about a rear wheel rotation axis RA2. The front wheel rotation axis RA1 and the rear wheel rotation axis RA2 are aligned parallel to each other.

[0031] The lifting vehicle 2 has a load movement device 14. The load movement device 14 comprises a lifting device 16 and a shifting device 20.

[0032] The lifting device 16 comprises a lifting guide rail 30, which is divided into a first part 28 and a second part 34. Furthermore, the lifting device 16 comprises a lifting carriage 32, on which two carriage wheels 26 rolling along the lifting guide rail 30 and a support element 18 are arranged.

[0033] The lifting device 16 is, on the one hand, for pivoting the second part 34 of the lifting guide rail 30 about a pivot axis SA into the tilting position according to Fig. 2. On the other hand, the lifting device 16 is designed to move the support element 18 from the first lifting position according to Fig. 1 in a lifting direction HR away from the floor level BE into the second lifting position according to Fig. 3. With the transfer of the support element 18 from the first lifting position to the second lifting position, the lifting carriage 32 transitions from the second part 34 into the first part 28 of the lifting guide rail 30.

[0034] The displacement device 20 has a displacement guide rail 22 and a displacement carriage 24. The displacement carriage 24, like the lifting carriage 32, has two carriage wheels 26. The carriage wheels 26 of the displacement carriage 24 roll along the displacement guide rail 22.

[0035] The first part 28 of the lifting guide rail 30 is arranged on the sliding carriage 24. As a result, the sliding device 20 can move the support element 18 with the first part 28 of the lifting guide rail 30 as a unit in the sliding direction VR, which is opposite to the direction of travel FR, into the sliding position according to Fig. 4. The shift position according to Fig. 4 is characterized in that the first part 28 of the lifting guide rail 30 and a part of the support element 18 are arranged between a front wheel rotation axis plane RAE1 and a rear wheel rotation axis plane RAE2. Said wheel rotation axis planes RAE1, RAE2 are aligned parallel to each other and perpendicular to the ground plane BE, with the front wheel rotation axis RA1 lying in the front wheel rotation axis plane RAE1 and the rear wheel rotation axis RA2 lying in the rear wheel rotation axis plane RAE2. A driver's cab 40 is arranged downstream of the displacement device 20 in the direction of travel FR.

[0036] The Fig. 5 and Fig. 6 illustrate a loading process of the lifting vehicle 2. Fig. 5 shows the lifting vehicle 2 after it has been moved with the support element 18 in the first lifting position in the direction of travel FR under a load 4. In addition, according to Fig. 5, a support element 36 is moved into a support position. In the support position, a support surface 38 of the support element 36 is spaced further from the rear wheel rotation axis RA2 than the front wheel rotation axis RA1. In the support position, the support surface 38 borders the ground plane BE. The following figures show the support element 36 in a travel position spaced from the ground plane BE.

[0037] Starting from Fig. 5, the support element 18 with the load 4 placed thereon is first moved into the second lifting position and then into the shifting position according to Fig. 6. The path S which the unit comprising the load 4 and the first part 28 of the lifting guide rail 30 travels in the displacement direction VR corresponds to more than 50% of the distance A between the wheel rotation axis planes RAE1, RAE2. Reference symbol: 2 lifting vehicles 4 Last 6 vehicle frame 8 Chassis 10 front wheel 12 rear wheel 14 Load moving device 16 Lifting device 18 supporting element 20 Shifting device 22 Sliding guide rail 24 sliding carriages 26 Sled wheel 28 first part 30 lifting guide rail 32 lifting carriages 34 second part 36 Support element 38 support surface 40 Driver's cab BE floor level FR direction of travel RA1 front wheel rotation axis RA2 rear wheel rotation axis HR lifting direction VR shift direction RAE1 front wheel rotation axis plane RAE2 rear wheel rotation axis plane SA swivel axis

Claims

[1] Lifting vehicle (2) for lifting and transporting loads (4), comprising a vehicle frame (6), a chassis (8) adjacent to a ground plane (BE), which is designed to move the lifting vehicle (2) in a direction of travel (FR) and has at least one front wheel (10) rotatably mounted about a front wheel rotation axis (RA1) and at least one rear wheel (12) rotatably mounted about a rear wheel rotation axis (RA2), which is oriented at right angles to the direction of travel (FR) and parallel to the front wheel rotation axis (RA1), at least in a straight-ahead position of the chassis (8), and arranged downstream of the front wheel (10) in the direction of travel (FR), and a load movement device (14) comprising a lifting device (16) having at least one support element (18) and designed to move the support element (18) relative to the vehicle frame (6) from a first lifting position into a lifting direction (HR) away from the ground plane (BE) into a second lifting position, characterized by , in that the load movement device (14) comprises a displacement device (20) which is designed for a translational movement of at least the support element (18) relative to the vehicle frame (6) from the second lifting position into a displacement direction (VR) which is oriented at an angle to the lifting direction (HR) and at least partially opposite to the direction of travel (FR). [2] Lifting vehicle according to claim 1, characterized by that the displacement device (20) is designed such that the displacement direction (VR) is aligned parallel to the ground plane (BE) at least in a first displacement device configuration. [3] Lifting vehicle according to one of the preceding claims, characterized byin that the displacement device (20) is designed such that the support element (18) in the displacement position is arranged at least partially between a front wheel rotation axis plane (RAE1), which is arranged at right angles to the ground plane (BE) and in which the front wheel rotation axis (RA1) lies, and a rear wheel rotation axis plane (RAE2), which is arranged at right angles to the ground plane (BE) and in which the rear wheel rotation axis (RA2) lies. [4] Lifting vehicle according to one of the preceding claims, characterized by that the displacement device (20) comprises at least one displacement carriage (24) and at least one displacement guide rail (22) for guiding the displacement carriage (24) in the displacement direction (VR). [5] Lifting vehicle according to claim 4, characterized by that the sliding carriage (24) has at least one carriage wheel (26) designed to roll on the sliding guide rail (22). [6] Lifting vehicle according to claim 4 or 5, characterized by that at least a first part (28) of a lifting guide rail (30) encompassed by the lifting device (16) for guiding a lifting carriage (32) of the lifting device (16) in the lifting direction (HR) is arranged on the sliding carriage (24). [7] Lifting vehicle according to claim 6, characterized by that the first part (28) of the lifting guide rail (30) is pivotally mounted relative to the sliding carriage (24) about a rotation axis which is oriented at right angles to the ground plane (BE) or parallel to the direction of travel (FR). [8] Lifting vehicle according to claim 6 or 7, characterized by that a second part (34) of the lifting guide rail (30), which is closer to the ground plane (BE) than the first part (28) of the lifting guide rail (30), is mounted on the vehicle frame (6). [9] Lifting vehicle according to claim 8, characterized bythat at least the second part (34) of the lifting guide rail (30) is pivotally mounted relative to the vehicle frame (6) about a pivot axis (SA) parallel to the ground plane (BE) and perpendicular to the direction of travel (FR). [10] Lifting vehicle according to one of the preceding claims, characterized by that the displacement device (20) has a drive motor for moving the support element (18) in the displacement direction (VR). [11] Lifting vehicle according to one of the preceding claims, characterized by that the lifting device (16) is designed to move the support element (18) relative to the vehicle frame (6) from the second lifting position into the lifting direction (HR) away from the ground plane (BE) into a third lifting position. [12] Lifting vehicle according to one of the preceding claims, characterized byat least one support element (36) which is mounted so as to be movable from a support position in which the support element (36) borders the ground plane (BE) with a support surface (38) which is further spaced from the rear wheel rotation axis (RA2) than the front wheel rotation axis (RA1), into a travel position away from the ground plane (BE). [13] Lifting vehicle according to one of the preceding claims, characterized by that the chassis (8) is designed such that the front wheel (10) and the rear wheel (12) are adjacent to the ground plane (BE). [14] Lifting vehicle according to one of claims 1 to 12, characterized by that the chassis (8) is designed as a crawler chassis with a crawler element rotating around the front wheel and the rear wheel. [15] Lifting vehicle according to one of the preceding claims, characterized by a driver's cab (40) in front of which the shifting device (20) is arranged in the direction of travel (FR).

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