freight vehicle with driver's cab

Abstract

To provide a driver's cab that ensures high-level driving comfortability in a transport vehicle.SOLUTION: A freight vehicle 1 is provided with: a frame 10 defining a support surface 11 for goods 2 to be transported; a plurality of rubberized wheel assemblies 13 with suspensions 14, the height of which can be adjusted between a lowered loading position and a raised transport position of the support surface; and a driver's cab 12 arranged beneath the support surface. The cab is coupled to, and overhanging, the frame by means of an articulated quadrilateral transmission unit and being shifted by pneumatic actuators. The pneumatic actuators are configured to vertically move the whole driver's cab in relation to the support surface between two extreme end positions, one approaching the support surface and one spaced apart from the support surface, and to arrange the driver's cab in a cushioned intermediate position for the transport of the goods.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority from Luxembourg patent application No. 101640, filed February 14, 2020, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a freight vehicle equipped with a driver's cab. [Background technology]

[0003] For example, in the field of storage and handling of cargoes of steel products such as steel bars, steel pipes, steel plate rolls or simple packs of steel plate, it is well known to arrange the cargoes to be handled on bridge-type support structures with dedicated portal frames or floor support legs.

[0004] To handle these cargoes, the use of rubberized vehicles configured to fit underneath the support structures described above is also known, each rubberized vehicle comprising a frame defining a support surface or load bed on which the support structure rests, a cab supported by the frame, and rubberized wheel assemblies supporting the frame.

[0005] The rubberized wheel assemblies have height adjustable suspension and are generally preferred over solid wheels with inner tubes as they are less susceptible to frequent puncture problems in particularly harsh environments such as steel mills.

[0006] In the above-described vehicle, the suspension height adjustment allows the support surface to be moved to a lowered, conforming or lowest position, which allows the vehicle to fit under the portal frame support structure.

[0007] Additionally, a height-adjustable suspension can raise the support surface, and with it the entire portal frame structure and its associated load, to an elevated transport position, in which the support legs of the portal frame support structure are lifted off the ground.

[0008] In the known vehicle, the cab is a dedicated cab, which is arranged completely below the support surface. This results in a very low cab height, which is sufficient to accommodate the driver on the one hand, and allows the frame to be placed in a low loading position on the other. For this purpose, the cab has its front part at the front of the vehicle. This front part is hinged to the frame by a hinge device for rotation about a fixed hinge axis parallel to the load support surface, and is permanently connected to the rear of the frame by an air spring. The air spring allows small vibrations about the fixed hinge axis under the control of suspension and damping elements.

[0009] Although known transport vehicles of the above-mentioned type are widely used, they are not very satisfactory from the point of view of driving comfort, especially when transporting loads, when the vehicle is inevitably subjected to vertical shocks and generally high vertical acceleration values, which are transmitted to the driver. Furthermore, the vertical accelerations are more noticeable to the driver when the tires are solid, since they have a lower cushioning effect than other tires.

[0010] In such a situation, the cab in fact follows the movements of the frame to which it is directly hinged, thus rattling the driver, despite the fact that the hinge arrangement may comprise a block of elastic material arranged around the fixed hinge axis, of the type known in commercial terms as a "silent block".

[0011] In some known solutions, the vertical stresses transmitted from the cab to the driver are partly alleviated by providing a cushioned seat, for example an air seat. Summary of the Invention [Problem to be solved by the invention]

[0012] However, while these seats offer good damping and a comfortable driving experience, they are also very bulky, as their height from the cab floor is significantly higher than that of conventional seats. Therefore, increasing the cab height is essential to prevent the driver's head from hitting the cab ceiling. This is because the distance of the cab floor from the wheel rolling surface cannot be reduced, as this distance is determined by the placement of the frame in its fixed position. The increased cab height necessarily raises the vehicle's support surface relative to the rolling surface when the load bed is in its lowered, adapted, or loaded, position.

[0013] However, this increase is strongly discouraged by users of handling services, especially steel mills, because it would require raising all existing portal frame support structures, which would entail high costs and adjustment times.

[0014] Moreover, raising the support surface of the portal frame structure means that existing transport vehicles will have to work under different conditions than those anticipated at the design stage, both in terms of fit or load conditions and in terms of transport conditions, which means that the useful travel of their suspensions will be reduced and the overall center of gravity will be shifted upward. [Means for solving the problem]

[0015] SUMMARY OF THE INVENTION The object of the present invention is to provide a cab for a transport vehicle that allows a simple and economical solution to the above problems.

[0016] In particular, the object of the present invention is to provide a cab for a transport vehicle which ensures a high level of driving comfort without requiring any changes in the dimensions of the support structure of the cargo to be handled or of the planned suspension configuration of vehicles already in operation.

[0017] A further object of the present invention is to provide a transport vehicle with a cab that can guarantee the driver a high level of driving comfort regardless of the condition of the rolling surfaces of the wheels of the wheel assembly and the type of wheels used on the same wheel assembly.

[0018] According to the present invention, a freight vehicle comprises: a frame defining a support surface for the cargo being handled; a plurality of rubberized wheels disposed below the frame, each wheel having a suspension; an adjustment means for adjusting the height of each of the suspensions to vary the height of the support surface above the rolling surface of the wheel; a cab disposed below the support surface; means for connecting the cab to the frame; a damping elastic means provided between the frame and the cab; Equipped with The coupling means comprises a crank drive unit and actuation means located between the frame and the cab, which are configured to move the entire cab perpendicular to the support surface between two opposite end positions, one close to the support surface and one remote from the support surface, and to position the cab in a cushioned intermediate position for transporting cargo.

[0019] The invention will now be described with reference to the accompanying drawings, which show non-limiting embodiments. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic perspective view of a support structure for the cargo to be handled placed on a freight vehicle equipped with a cab according to the invention; [Figure 2] 2 is a side view of the cab of the vehicle shown in FIG. 1 in a certain state. [Figure 3] 2 is a side view showing the driver's cab of the vehicle shown in FIG. 1 in another state. [Figure 4]2 is a side view showing the driver's cab of the vehicle shown in FIG. 1 in another state. DETAILED DESCRIPTION OF THE INVENTION

[0021] In Figure 1, reference number 1 indicates as a whole a freight vehicle 2 for transporting, for example, steel products.

[0022] In particular, the vehicle 1 is a vehicle configured for loading and handling cargo, arranged on a portal frame or bridge support structure 4, known per se, and of the type comprising a support platform 5 for the cargo 2 to be handled, and a plurality of columns 6. Each column 6 has an upper part firmly connected to said platform 5 and a base which provides a support leg 7 resting on the rolling surface 8 of the vehicle 1. The support legs 7 rest on surface 8 when the platform 5 is loaded with cargo and when the platform itself is placed on the vehicle, as shown by dotted lines in Figure 1. Instead, at the end of the loading of the vehicle 1 and during the transport phase, the support legs are lifted from said surface 8 itself, as shown by solid lines in Figure 1.

[0023] Referring again to FIG. 1, the vehicle 1 comprises a support surface or load bed 11 on which the platform 5 rests, a cab 12, and a plurality of rubberized wheel assemblies 13 connected to the frame 10, which is known and will not be described in detail.

[0024] The wheel assemblies 13 are provided with corresponding height-adjustable suspensions 14. These suspensions 14 are known per se and are shown only diagrammatically in Figure 1, with corresponding wheels 15 rolling in contact with a surface 18. Conveniently, these wheels 15 are solid wheels.

[0025] Each suspension 14 is provided with several hydraulic adjustment cylinders 16, known per se and shown diagrammatically, which are capable of moving the frame 10 relative to the surface 8 between a fully lowered loading position or minimum height position of the support surface 11, in which the support surface 11 is located below the platform 5 so that the vehicle 1 can slide under the structure 4, and a raised transport position (FIG. 1), in which the platform 5 lies on the surface and the support legs 7 are lifted from the surface 8 so that the vehicle 1 can move in the forward direction 18.

[0026] Referring again to FIG. 1, a cab 12 is configured below the frame 10 and has a rear portion 12A and a floor 12B on which rests a conventional seat (not shown) positioned for the driver of the vehicle 1.

[0027] The cab 12 is connected by an electric elastic transmission unit 20 to the front 19 of the device 10 facing the rear 12A, and is configured to allow the entire cab 12 to move vertically relative to the frame 10 from and towards the face 11 of the frame 10 itself, and also from and towards said face 8 when in use.

[0028] 2-4, the transmission unit 20 comprises two electrically driven articulated quadrilateral transmissions 21 located on opposite sides of the cab 12, only one of which is shown in FIGS.

[0029] Each transmission 21 comprises a lower crank 22 and an upper crank 23 of the same length.

[0030] Cranks 22 and 23 are hinged on one side to the front of frame 19 by respective hinge pins and are adapted to rotate relative to frame 10 about respective fixed hinge axes 25. The respective fixed hinge axes 25 are spaced apart in the vertical direction. On the other hand, they are hinged on the rear of cab 12 by respective hinge pins and are adapted to rotate relative to frame 10 about respective movable hinge axes 26. The respective movable hinge axes 26 are spaced apart in the vertical direction.

[0031] Conveniently, the distance between the hinge axes 25 is equal to the distance between the other hinge axes 26. In this way, each transmission 21 is an indirect quadrilateral transmission.

[0032] 2 to 4, each transmission 21 has its own air actuator 30. The air actuator is pressure-controlled, for example, by being controlled by a known leveling valve (not shown). On the one hand, each actuator 30 is hinged at its rear to the front part 19 at the same height from the ground as the axis 25 of the crank 22, thereby rotating about an axis 31 parallel to the axis 25. On the other hand, each actuator is hinged to the free end of a respective bracket 32. The bracket 32 is permanently connected to the rear part 12A and protrudes from said rear part 12A towards the front part 19 of the frame 10. Conveniently, each bracket 32 is permanently connected to half of the rear part 12A.

[0033] Finally, each transmission 21 comprises a damping element 33 known per se, which comprises a sleeve 34 hinged to the front part 19 for rotation about the axis 25 of the crank 22, and a stem 35 hinged to the crank 23 coaxially with its axis 26.

[0034] 2 to 4, the unit 21 includes a position transducer 36 for detecting the actual height position of the cab 12 relative to the frame 10 when the driver is on board so as to adjust the position of the cab 12 to take into account the weight of the driver. Conveniently, the transducer 36 is an angle transducer coupled to one of the axes 25. Alternatively, the transducer 36 is coupled to the axis 26 or the axis 31.

[0035] In one variation, the transducer 36 is a linear transducer mounted between the frame 10 and the cab 12 .

[0036] In use, the springs 30 are controlled in synchronization with the suspension 14 to shift the cab 12 perpendicular to the frame 10 and thus to the support surface 11 between two opposite end operating positions. One of these positions is a raised position, as shown in Figure 4, in which the cab 12 is positioned adjacent to the surface 11 to allow the frame 10 to move to its lowered or minimum height position. The other is a lowered position, as shown in Figure 3. In the lowered position, the cab 12 is spaced from the surface 11 and raised just enough to avoid scraping against the surface 11.

[0037] Conveniently, but not necessarily, the springs 30 are fully compressed when the cab 12 is in its lowered position. Since the cab low condition occurs when the vehicle is stationary or moving forward at very slow speeds, fully compressed springs 30 do not present any substantial problems in terms of driving comfort, and therefore the driver is not subject to any appreciable vertical acceleration in practice.

[0038] However, in driving or load-moving conditions, the cab 12 is placed in an intermediate position between the two opposite positions, such as that shown in Figure 2. In the latter case, when subjected to vertical accelerations, the cab is free to oscillate vertically relative to the frame 10 and load bed 11 under the sole control of the springs 30 and dampers 33, ensuring a high degree of driving comfort for the driver at all times.

[0039] As is apparent from the above, the special elastic and damped articulated parallelogram configuration of group 20 allows high or controlled vertical movement of cab 12, thus effectively reducing or damping the vertical acceleration transmitted to the driver.

[0040] This is due to the fact that, compared to known solutions, the crank unit 20 essentially eliminates the rigid vertical connection between the cab 12 and the frame 10 that exists with a direct coupling of the cab to the frame.

[0041] At the same time, again in comparison with known solutions, the unit 20 allows the vertical dimensions of the conventional cab to be kept unchanged, and therefore both the distance from the ground of the loading platform 5 of the structure 4 and the functional or operational condition of the suspension 14 of the conventional wheel assembly 13 (both in loading conditions and during transport) are also kept unchanged.

[0042] In other words, the transmission unit 20 ensures the high driving comfort required by the most stringent regulations in force, while at the same time allowing the use of both conventional portal frame support structures and current transport vehicles sized according to the characteristics of these same support structures.

[0043] Moreover, the structural features of the unit 20 make it completely autonomous and independent, allowing for a very simple, economical and fast retrofit or modernization of current transport vehicles.

[0044] Finally, the articulated parallelogram transmission makes it possible to shift the wheel carriage 12 between the extreme positions mentioned above while keeping the running wall 12B of the wheel carriage 12 itself parallel to itself, to the support surface 11 and substantially to the rolling surface of the wheels 5. This differs from known solutions in which a hinge connection with a fixed axis of rotation allows the running wall to rotate about a fixed hinge axis relative to the frame of the vehicle.

[0045] No rotation occurs between the walking wall 12B and the support surface 11, and therefore the rolling surface, which leads to improved driving comfort.

[0046] From the above, it is clear that modifications and variations can be made to the crank unit 20 described herein without departing from the scope of the claims. In particular, the articulated parallelogram transmission 21 may comprise a different number or configuration of cranks 22, 23, which may also have different lengths. In particular, it would be possible to provide only one transmission 21.

[0047] Not only that, the air springs 30 and / or dampers 33 may also be positioned in different locations than those shown as examples, and therefore several springs 30 and / or dampers 33 other than those shown may be provided. [Explanation of symbols]

[0048] 1 vehicle 2 cargo 5 Platform 10 frames 11 Support surface 12 Driver's cab 12A rear 12B floor 13 Wheel Assembly 14. Suspension 15 wheels 16 Hydraulic adjustment cylinder 20 Transmission unit 21 Transmission 22 Lower crank 23 Upper crank 25 Fixed hinge axis 26 Movable hinge axis 30 Air spring 33 Damping Elements 36 Position transducer

Claims

1. a support frame defining a support surface for the cargo being handled; a plurality of rubberized wheels disposed below the support frame, each wheel having a suspension; an adjustment means for adjusting the height of each of the suspensions to vary the height of the support surface above the rolling surface of the wheel; a cab disposed below the support surface; a connecting means for connecting the cab to the support frame; a damping elastic means provided between the support frame and the cab; In a freight vehicle equipped with the coupling means comprises a crank transmission unit and actuation means interposed between the support frame and the cab, the crank transmission unit and actuation means being configured to move the entire cab perpendicular to the support surface between two opposite end positions, one close to the support surface and one remote from the support surface, and to place the cab in a cushioned intermediate position for carrying a load; 10. A goods vehicle, wherein said actuation means comprises at least one air spring which is a pneumatic actuator having a pressure controllable by a valve.

2. 2. The vehicle according to claim 1, wherein the crank transmission unit comprises several cranks, which are hinged on one side to the support frame for rotation about respective fixed hinge axes relative to the support frame, and are hinged to the cab for rotation about movable hinge axes parallel to the fixed hinge axes.

3. 3. A vehicle as claimed in claim 2, wherein said crank forms part of at least one articulated quadrilateral transmission.

4. 4. A vehicle according to claim 2 or 3, wherein the cranks are all the same length.

5. 5. A vehicle according to claim 3 or 4, wherein the crank forms part of two articulated quadrilateral transmissions, the two articulated quadrilateral transmissions being arranged on opposite sides of the cab.

6. 6. A vehicle according to claim 2, wherein the crank extends in a parallel position regardless of the position of the cab relative to the support surface.

7. 7. A vehicle as claimed in any one of claims 1 to 6, wherein the cab extends beyond an end of the support frame.

8. 8. A vehicle according to any one of claims 1 to 7, wherein the cab has a rear portion, and the crank transmission unit is disposed between the rear portion and a front portion of the support frame facing the rear portion.

9. 9. A vehicle according to any one of claims 1 to 8, wherein the cab has a lower walking wall, and the crank transmission unit and the actuating means are configured to keep the angle of the lower walking wall constant relative to the support surface regardless of the position of the cab in the opposite end positions.

10. 10. A vehicle according to any one of claims 1 to 9, wherein the air spring is a pneumatic actuator.

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