Walk-behind load handling machine

Abstract

Load handling device (1) comprising a U-shaped frame (2), lifting forks (3) arranged between the arms (5) of the U, a steering control device (6), two rear wheels (71) arranged at the level of the arms (5) of the U, a front steering wheel (8) arranged vertically or in front of the web (4) of the U, and two towing wheels (9) arranged between the front wheel (8) and the rear wheels (71). The front wheel (8) is mounted to move upwards and downwards relative to the frame (2) to allow the towing wheels (9) to move, depending on the position of the front wheel (8), from a working position in which the towing wheels (9) extend at least partially over the front wheel (8), to a transport position in which the towing wheels (9) extend at least partially under the front wheel (8). Figure for the abbreviation: Fig. 1

Description

Title of the invention: Walker-operated load handling device

[0001] The present invention relates to a walk-behind load handling device.

[0002] It relates in particular to a walk-behind load handling machine comprising a chassis at least partially in the shape of a horizontal U with the web of the U considered as forming the front of the chassis, movable forks mounted for raising and lowering arranged between the arms of the U, a steering control element and wheels suitable for supporting the chassis said to be rolling, said wheels comprising at least two wheels said to be rear arranged at the level of the arms of the U and a front wheel arranged vertically or in front of the web of the U taken with respect to the front rear direction of the chassis, said front wheel being mounted for rotation about a directional axis said to be vertical parallel to the direction of movement in raising and lowering of the forks to form a steering wheel, the steering control element being active on the front wheel, the machine comprising at least two additional wheels said to be towing wheels arranged between the front wheel and the rear wheels.

[0003] A conventional load-handling machine, i.e., one without towing wheels, is not suitable for road transport due to the fragile nature of its front and rear wheels and its maximum speed. However, there is a need to transport such a machine from one site to another. Loading such a load-handling machine onto a carrier vehicle requires a specific carrier vehicle, making transport expensive. To solve this problem, the idea arose of designing the machine so that it could be coupled to a tractor vehicle. However, current solutions are not entirely satisfactory.

[0004] An object of the invention is to provide a load handling device of the aforementioned type whose design is improved to increase the reliability and robustness of the handling device when towing the handling device.

[0005] To this end, the invention relates to a walk-behind load-handling device comprising a chassis at least partially in the shape of a horizontal U, with the web of the U considered as forming the front of the chassis, movable forks mounted for raising and lowering, arranged between the arms of the U, a steering control device, and wheels adapted to support the rolling chassis, said wheels comprising at least two rear wheels arranged at the level of the arms of the U and a front wheel arranged vertically or in front of the web of the U considered with respect to the forward / rear direction of the chassis, said front wheel being mounted to rotate about a directional axis called vertical parallel to the direction of movement in raising and lowering of the forks to form a steering wheel, the steering control device being active on the front wheel, the machine comprising at least two additional wheels called towing wheels disposed between the front wheel and the rear wheels, characterized in that the front wheel is mounted movable in raising and lowering relative to the chassis to allow the towing wheels to pass, depending on the position of the front wheel, from a position called the working position of the machine in which the towing wheels extend at least partially over the front wheel so that the machine rests on the ground at least by the front wheel,to a so-called transport position in which the towing wheels extend at least partially below the front wheel so that the machine rests on the ground by the towing wheels.

[0006] The up-and-down movement of the front wheel, combined with the presence of the towing wheels, offers numerous advantages. This combination eliminates the need to maintain pressure on the towing axle in the lowered transport position. The forces involved in moving the front wheel from the working position to the transport position are also limited, since the machine's weight accompanies the upward movement of the front steering wheel until it makes contact with the towing wheels, whereas lowering the axle of the towing wheels would require lifting the machine. Thanks to this combination, it is never necessary to lift the machine's weight to move from one position to another.

[0007] According to one embodiment of the invention, at least a part of the towing wheels extend in a vertical plane passing through the center of gravity of the machine in the position of the machine on a horizontal flat surface.

[0008] Positioning the towing wheels substantially at the center of gravity of the machine makes it possible to limit the effort required to lift the coupling hitch to the towing vehicle and similarly the effort required to support the coupling hitch on the tow ball of a towing vehicle.

[0009] According to one embodiment of the invention, the device comprises a mast along which the front steering wheel is mounted to slide freely. Preferably, the device comprises, for this sliding movement of the front wheel along the mast between a lower position and a higher position, at least one actuator disposed between the front wheel and the mast.

[0010] According to one embodiment of the invention, the machine comprises a coupling of the machine to a tractor vehicle.

[0011] According to one embodiment of the invention, the coupling is a removable or retractable coupling.

[0012] According to one embodiment of the invention, the coupling is configured to be positioned at the rear part of the chassis.

[0013] According to one embodiment of the invention, the hitch is configured to be positioned at the front part of the chassis.

[0014] According to one embodiment of the invention, the coupling comprises at least one coupling bar coupled to the chassis by a removable and / or pivoting link.

[0015] According to one embodiment of the invention, the device is equipped with a load sensor and a control unit.

[0016] According to one embodiment of the invention, the coupling has an active configuration and an inactive configuration, and the control unit is configured to enable or disable the active configuration based on data provided by said load sensor. The presence of a load sensor prevents the machine from moving into the transport position when a load is present on the forks. Brief description of the drawings

[0017] The invention will be better understood upon reading the following description of exemplary embodiments, with reference to the accompanying drawings in which:

[0018] [Fig-1] represents a perspective view of a load handling device according to the invention taken from the front of the chassis with an associated detail view;

[0019] [Fig.2] represents a partial perspective view of a handling device load according to the invention taken from the rear of the chassis, the towing wheels and the coupling having been omitted;

[0020] [Fig.3] represents a side view of the machine in the working position with a view to the passage from the working position to the transport position of the load handling equipment;

[0021] [Fig.4] shows a side view of the machine in the raised position of the front wheel corresponding to the transport position in the unhitched state of the coupling to a tractor vehicle;

[0022] [Fig. 5] shows a side view of the machine in the raised position of the front wheel corresponding to the transport position when coupled to a tractor vehicle;

[0023] [Fig.6] represents a partial top view of a handling device conforming to the invention.

[0024] The invention relates to a load-handling device 1 of the type shown in Figures 1 to 4. This load-handling device 1 has an operator walking alongside the device 1. This load-handling device 1 comprises a chassis 2, at least a portion of which is in the shape of a horizontal U. The U has two arms shown at 5 and a web connecting said arms 5 and shown at 4. The web of the U is considered, by convention, to form the front of chassis 2, while the free ends of the 5 arms of the U form the rear of chassis 2.

[0025] This device 1 includes, for handling loads, and in a manner known in itself, forks 3 extending between the arms 5 of the U of the chassis 2. The chassis 2 includes a mast 11 along which the forks 3 move between a high position away from the ground and a low position close to the ground.

[0026] The drive system for raising and lowering the forks 3 can be formed by an actuator, such as a cylinder, extending between the frame 2 and the forks 3. This well-known drive system is of little importance to the invention. It will therefore not be described in detail.

[0027] The machine 1 also includes a steering control element 6. This steering control element 6 is in the form of a drawbar coupled to the yoke of the front wheel 8, which will be described below. Again, such a drawbar is typical for this type of machine.

[0028] The front wheel 8 of the machine is arranged vertically or in front of the web 4 of the U taken with respect to the front / rear direction of the chassis 2. This front wheel 8 is mounted to rotate around a directional axis XX' called vertical parallel to the direction of movement in raising and lowering of the forks 3 to form a steering wheel.

[0029] The directional control element 6 is active on the front wheel 8. Thus, the drive in rotational displacement of the drawbar around the axis XX' generates in parallel the drive in rotation of the front wheel 8 around this same axis.

[0030] The device 1 further comprises two rear wheels 71 and 72 arranged at the level of the arms of the U, in particular in the vicinity of the free ends of the arms 5 of the U. These rear wheels are, in the example shown, drive wheels each equipped with a motor for driving the rotation of the wheel.

[0031] The machine 1 further includes two additional wheels called towing wheels 9. These towing wheels 9 are arranged between the front wheel 8 and the rear wheels 71 and 72. The front wheel 8 is, as illustrated by Figures 3 and 4, mounted movably up and down relative to the chassis 2 to allow the towing wheels 9 to move, depending on the position of the front wheel, from a so-called working position of the machine in which the towing wheels 9 extend at least partially over the front wheel 8, so that the machine rests on the ground at least by the front wheel 8, in this case by the front wheel 8 and the rear wheels 71 and 72, to a so-called transport position in which the towing wheels 9 extend at least partially under the front wheel 8, so that the machine 1 rests on the ground by the towing wheels 9.

[0032] In the transport position, the front wheel, which is mounted to move upwards and downwards relative to the chassis 2 for the passage from a low position in contact with the ground to A raised position, away from the ground, is in the high position. Conversely, in the working position, it is in the low position. In this low position, it supports at least part of the machine's weight.

[0033] To enable such an up and down movement of the front wheel 8, the front wheel 8 is mounted to slide along the mast 11. For this purpose, the front wheel 8 and the steering control member 6 form an assembly that is mounted to slide up and down along the mast 11.

[0034] The mast 11 is equipped with vertical rails parallel to the direction of upward and downward movement of the forks, along which the steering control unit / front wheel assembly slides. This sliding movement is achieved by means of an actuator, such as a cylinder 15, disposed between said assembly and the chassis 2.

[0035] At least part of the towing wheels 9 extend in a vertical plane passing through the center of gravity of the machine 1 in the positioned state of the machine 1 on a horizontal flat surface.

[0036] Thus, it is easy to lift the parts of the chassis 2 extending on either side of the towing wheels 9 by pivoting the chassis 2 around said towing wheels 9. This facilitates the coupling operations of the machine.

[0037] Indeed, the machine 1 includes a coupling 10 for connecting the machine 1 to a tractor vehicle 16. Preferably, this coupling 10 is a removable or retractable coupling. This coupling 10 is configured to be positioned at the rear of the chassis 2, as illustrated in [Fig. 3]. Alternatively, this coupling 10 can be configured to be positioned at the front of the chassis 2. Preferably, the coupling 10 includes at least one drawbar coupled to the chassis 2 by a removable and / or pivoting linkage 12. An example of this linkage 12 is shown in Figures 4 and 5.

[0038] When the coupling 10 corresponds at least to a pivoting drawbar, said drawbar can pivot around a horizontal axis transverse to the front / rear direction of the chassis to move from a position in which it extends beyond the rear of the chassis and in particular the rear wheels of the chassis in the transport position of the machine to a working position in which it extends between the arms of the U of the chassis in the working position of the machine 1. This drawbar can have a more or less complex shape and can in particular, if necessary, divide into several arms.

[0039] In the transport position and when coupled to a tractor vehicle 16, for example, at the tractor vehicle's tow ball, the machine 1 rests on the ground by its towing wheels 9, and the front wheel 8 and the rear wheels 71 and 72 of the machine 1 are raised off the ground. In the transport position and when uncoupled to a tractor vehicle 16, the machine 1 rests on the ground by its towing wheels 9 and its rear wheels 71 and 72.

[0040] To put the machine 1 into working position, it is sufficient to uncouple the machine 1 from the tractor vehicle 16 so that the machine 1 can rest on the ground by the towing wheels 9 and the rear wheels 71 and 72 before lowering the front wheel 8 to a ground support position of the front wheel 8. The lowering movement of the front wheel 8 is preferably continued until the towing wheels 9 are away from the ground.

[0041] Alternatively or in addition, the towing wheels 9 may, like the front wheel 8, include a drive device for raising and lowering to assist in raising them into the working position of the machine 1.

[0042] To complete the device 1, the device 1 is equipped with a load sensor 13 and a control unit 14. This control unit 14 is in the form of an electronic and / or computer system which includes, for example, a microprocessor and working memory. In one particular configuration, the control unit may be in the form of a programmable logic controller (PLC). In other words, the functions and steps described can be implemented either as a computer program or via hardware components (e.g., programmable gate arrays).In particular, the functions and steps performed by the control unit or its modules can be carried out by instruction sets or computer modules implemented in a processor or controller, or by dedicated electronic components, or by components such as field-programmable gate arrays (FPGAs), or application-specific integrated circuits (ASICs). It is also possible to combine computer and electronic components.When it is specified that the unit or means or modules of said unit are configured to perform a given operation, this means that the unit includes computer instructions and the corresponding means of execution which enable said operation to be performed and / or that the unit includes corresponding electronic components.

[0043] The coupling 10 has an active configuration and an inactive configuration, and the control unit 14 is configured to allow or prevent the active configuration according to the data provided by the load sensor 13.

[0044] The active configuration of the coupling 10 corresponds, in the case of a pivoting drawbar, to the position where the drawbar extends beyond the rear wheels of the machine, while the inactive configuration of the coupling 10 corresponds to the position where the drawbar extends between the arms of the U of the chassis.

[0045] A lock can prevent the transition from one position to another based on the data provided by the load sensor 13. Thus, when the load sensor 13 indicates the presence of a load on the forks, the transition of the coupling 10 to the active configuration is prevented.

[0046] The active configuration of the coupling 10 can, alternatively, correspond to the mounted state of the coupling 10 on the chassis 2 while the inactive configuration of the coupling 10 corresponds to the dismounted state of the coupling 10 from the chassis 2.

[0047] As illustrated in Figures 3 and 4, and as described above, the transition from the working position to the transport position of the machine 1 and vice versa is extremely simple to achieve since it can be done by simply raising or lowering the front wheel 8.

[0048] In working position, such a load handling machine operates in the same way as a traditional load handling machine.

Claims

Demands

1. A walk-behind load-handling device (1) comprising a chassis (2) at least partially in the shape of a horizontal U with the web (4) of the U considered as forming the front of the chassis (2), forks (3) mounted movably for raising and lowering arranged between the arms (5) of the U, a steering control element (6) and wheels suitable for supporting the chassis (2) said to be rolling, said wheels comprising at least two wheels said to be rear (71, 72) arranged at the level of the arms (5) of the U and a front wheel (8) arranged vertically or in front of the web (4) of the U taken with respect to the front / rear direction of the chassis (2), said front wheel (8) being mounted for rotation about a directional axis (XX1) said to be vertical parallel to the direction of movement for raising and lowering of the forks (3) to form a steering wheel, the steering control element (6) being active on the front wheel (8),The device (1) comprising at least two additional wheels, referred to as towing wheels (9), arranged between the front wheel (8) and the rear wheels (71, 72), characterized in that the front wheel (8) is mounted to move upwards and downwards relative to the chassis (2) to allow the towing wheels (9) to move, depending on the position of the front wheel (8), from a working position of the device (1) in which the towing wheels (9) extend at least partially over the front wheel (8) so that the device (1) rests on the ground at least by the front wheel (8), to a transport position in which the towing wheels (9) extend at least partially under the front wheel (8), so that the device (1) rests on the ground by the towing wheels (9), in that the device (1) comprises a coupling (10) for the device (1) to a towing vehicle (16), said coupling (10) being configured to be positioned at the rear part of the chassis (2).

2. Load handling device (1) according to claim 1, characterized in that at least a part of the towing wheels (9) extend in a vertical plane passing through the center of gravity of the device (1) in the positioned state of the device (1) on a horizontal flat surface.

3. Load handling device (1) according to any one of claims 1 or 2, characterized in that the device (1) comprises a mast (11) along which the front steering wheel (8) is mounted movable by sliding.

4. Load handling device (1) according to any one of claims 1 to 3, characterized in that the coupling (10) is a removable or retractable coupling.

5. Load handling device (1) according to any one of claims 1 to 4, characterized in that the coupling (10) comprises at least one drawbar coupled to the chassis (2) by a removable and / or pivoting link.

6. Load handling device (1) according to any one of claims 1 to 5, characterized in that the device (1) is equipped with a load sensor (13) and a control unit (14).

7. Load handling device (1) according to claim 6, characterized in that the coupling (10) has an active configuration and an inactive configuration and in that the pilot unit (14) is configured to allow or prevent the active configuration according to the data provided by said load sensor (13).

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