EP2377806B1

EP2377806B1 - Forklift truck

Info

Publication number: EP2377806B1
Application number: EP11162525.7A
Authority: EP
Inventors: Mario Di Biase
Original assignee: MDB SRL
Current assignee: MDB SRL
Priority date: 2010-04-14
Filing date: 2011-04-14
Publication date: 2016-04-13
Anticipated expiration: 2031-04-14
Also published as: EP2377806A1; ITCH20100011A1

Description

This invention concerns a forklift truck.
In particular, the forklift truck is of the self-propelling type with forks, particularly used for the movement of loads in the road haulage industry.
Said forklift truck is preferably fitted with caterpillar tracks and comprises a tractor unit with a frame and rear driving and control apparatus that can be worked by a driver. The forklift truck is also fitted with a device for the handling of loads, comprising in its turn a mostly vertical portal connected to the frame, a first slide with a load support fork and a second slide; both slides are connected to the portal. Finally, the forklift truck comprises first and second actuator devices that can perform the sliding along a first direction of the first slide, substantially vertical, to allow the raising and lowering of the loads, and along a second, substantially horizontal, direction of the second slide.
Forklift trucks of the above mentioned type are disclosed for example in documents JP-A-7 215693 and DE-U1-94 19 833 .
The forklift trucks used in the road haulage industry are usually housed in compartments specially arranged inside the trailer of the vehicles.
In traditional versions, the forklift trucks and, consequently, the compartments arranged to contain them, are particularly large. Because of their bulk, commonly used forklift trucks have the disadvantage of reducing the payload of the trailers of the vehicles.
The purpose of this invention is therefore to provide a forklift truck that can overcome the disadvantages of commonly used models. In particular, the purpose of this invention is to provide a forklift truck that has reduced overall dimensions, to allow for easy manoeuvring of the truck, as it often operates in tight spaces, and that is also stable when there is a load on the support fork, and, finally, that keeps the costs of handling loads down.
According to this invention a forklift truck is further provided according to what is claimed in claim 1 and, preferably, in any one of the later claims directly or indirectly dependent on claim 1.
This invention will now be described in relation to the attached drawings, which illustrate a number of non-limiting examples of actuation:

figure 1 is a perspective rear view of a first manner of use of a forklift truck built in accordance with this invention; in this view, the portal is in the operational position at the front edge of the tractor unit and the fork is in a lowered position;
figure 2 is a side view of the forklift truck in figure 1;
figure 3 shows a detail of the forklift truck in figure 1;
figure 4 is a plan of the forklift truck in figure 1; in this view, the portal is bent back onto the tractor unit;
figure 5 is a side view of the forklift truck in figure 4 with the portal bent back onto the tractor unit;
figure 6 is a perspective front view of the forklift truck in figure 4 with the portal bent back on the tractor unit;
figure 7 is a rear perspective view of a second manner of use of a forklift truck not made in accordance with this invention; in this view, too, the portal is in the operating position at the front edge of the tractor unit and the fork is in the lowered position; and
figure 8 is a worm's eye view of the forklift truck in figure 7.

In the attached figures, number 1 indicates a forklift truck in its entirety.
Forklift 1 comprises a tractor unit 2 and a load lifting and handling device 3 (not shown).
Device 3 comprises in its turn a fork 4 that can lift the load (not shown). Tractor unit 2 comprises a pair of caterpillar trucks, indicated with 5 and 6 respectively, on which a frame 7 is fitted. Frame 7 has a compartment 8 connected to it near the rear end that houses the engine unit fitted with a fuel tank, an oil tank, an electronic control unit (partially shown in figures 3 and 6) and a control panel 9 comprising several levers 10 through which an operator can give the forklift 1 the commands necessary for its operation and the movement of fork 4. Frame 7 has a front edge 11.
The load lifting and handling device 3 comprising, in its turn, a portal 12 standing vertically on which a slide 13 slides on which fork 4 is fitted.
Fork 4 comprises two teeth 4* supported by the slide 13 comprising, in its turn, a front plate 14. According to what is shown in figures from 1 to 6, the two teeth 4* are hinged to the front plate 14. In particular, the two teeth 4* swivel around an axis A1 of shared rotation, between an operating position for the raising and handling of the load in which the teeth 4* are arranged at right angles to the front plate 14 and a bent position in which the teeth 4* are arranged in contact with a front surface of the front plate 14. In the bent position, the teeth 4* are coplanar to the front plate 14 (as shown in figure 6). Between the operating position and the bent position, the teeth 4* perform a rotation of about 90°.
The portal 12 comprises two struts 15 that are substantially vertical and parallel to each other. Each strut 15 defines a respective guide internally in which slide 13 slides.
Portal 12 is finished off by two side appendages 16 fixed to two lateral struts 15 and several crossbeams 17 to strengthen said portal. The crossbeams 17 are also used to support a hydraulic actuator 18 (of a common type and not described in detail), that acts on slide 13 to command its translation in a vertical direction along the axis Y between an extreme upper position and an extreme lower position.
In other words, the hydraulic actuator 18 is fitted with a mobile stem that can move the fork 4 from a lower material loading position shown in figures 1 and 2 to a position of maximum extension of its stem, and vice versa.
The two side appendages 16 define a slide 16*, support the portal 12 and slide in the respective guides 19 of the frame 7, that extend horizontally and are parallel to each other. The two guides 19 are arranged to allow a movement of the slide 16* (and consequently of the portal 12) along the horizontal direction X. The movement in the horizontal direction is commanded by hydraulic actuator 20 that at a front end is directly connected to a lower crossbeam 17* of the portal 12, while at a rear end it is directly connected to frame 7 and is housed inside the compartment 8.
The stem of the hydraulic actuator 20 acts directly on the lower crossbeam 17* of the portal 12 to command its translation in a horizontal direction along the x axis, between an extreme advanced position and an extreme retracted position.
As known, forklift trucks 1 that allow a translation both in a vertical direction Y and in a horizontal direction X have the advantage of optimising the positioning of the load on the frame 7, as far as the stability and the bulk of the load itself are concerned.
Finally, the fork lift 1 comprises a further hydraulic actuator 21 that is arranged in such a way as to allow closure movement of the portal 12. As better shown in figures 2 and 3, the lower crossbeam 17* comprises the pair of protruding rear appendages 22 that are hinged on the slide 16*. In detail, each pair of rear appendages 22 is paired with a side appendage 16 and swivels around an axis A2 of shared rotation, between an operational position, in which the portal 12 is substantially at right angles to the slide 16*, and a bent position, where the portal 12 is arranged in coplanar fashion to the slide 16* (as shown in figure 6). Between the operating position and the bent position, the portal 12 performs a rotation of about 90°.
In addition to appendices 16, the slide 16* comprises side arms with the number 23, in their turn connected at one of their ends to a rear element 24. The rear element 24 comprises a side wall 25 in which a gap is included to allow the said rear element 24, and consequently the entire slide 16*, to slide in the guide 19 without interfering with the hydraulic actuator 20.
The hydraulic actuator 21 is connected at a front end to the lower crossbeam 17* and at its rear end to a side of the rear element 24. In this way, even when the portal 12 is completely bent, the hydraulic actuator 21 is alongside the hydraulic actuator 20, without overlapping, in such a way as to optimise the overall bulk.
When the portal 12 is in the operating position in which it is arranged at a right angle to the slide 16*, the stem 21A of the hydraulic actuator 21 is in a position that is completely outside with respect to the cylinder 21B of said hydraulic actuator 21. When, on the other hand, portal 12 is bent on the slide 16*, the portion of stem 21A outside the cylinder 21B is minimum. The action of hydraulic actuator 21 allows the portal 12 to be arranged selectively, in the operating position and in the bent position.
It is important to point out that in the completely bent position portal 12 does not interfere in the slightest with compartment 8, that is housed in an area behind the frame 7.
It is clear for experts in the field that, without leaving the field of this invention, it is possible to build the forklift 1 referred to in this invention with load lifting and handling devices 3 that are different from those that were described above. For example, the raising and handling device 3 could comprise a shelf rather than the fork 4.
Furthermore, although the tractor unit 11 may be fitted with wheels (not shown), the most advantageous solution is represented by the adoption of the tracks 5, 6 which allow for a great distribution of the strains on the ground and a better balance, to avoid the fork lift 1 tipping forward when the portal 12 is in the full forward position. Furthermore, depending on a favourite variant, tracks 5 and 6 are adjustable in such a way as to vary the width from a minimum width to a maximum width, where the minimum width is preferably 130 cm and the maximum width is preferably 170 cm.
Figures 7 and 8 show an improvement of the forklift truck shown in figures from 1 to 6, not built according to the specifications of this invention.
In figures 7 and 8, the corresponding parts of the different forms of actuation are marked wherever possible with the same reference numbers used in the figures from 1 to 6.
The form of actuation shown in figures 7 and 8 differ from each other only in the fact that the hydraulic actuator 20 shown in figures from 1 to 6 has been replaced by actuator devices 26 that comprises a system 27 with rack with gear reducer (of a common type and not described in detail), that commands the horizontal movement to allow for the translation of the portal 12 in a horizontal direction along the X axis from the full forward position to the fully retracted position.
According to a preferred variant, when the portal 12 is bent on the slide 16* and the teeth 4* of the fork 4 are bent into contact with the front plate 14, the forklift 1 has an overall height of about 69 cm.
In the completely bent configuration, the forklift 1 is very compact. The reduction of the overall dimensions of the forklift 1 is obtained by making the portal 12 mobile and capable of positioning itself in a coplanar fashion with frame 7 and positioning the compartment 8 at one of its rear ends of the frame 7 in such a way that it does not interfere with the movement of the portal 12.
The forklift 1 described up to this point therefore has the advantage of being easily inserted inside a compartment of reduced dimensions inside the trailer of a vehicle, without compromising the payload of the trailer itself.

Claims

Forklift truck (1) for the movement of loads, in particular in the road haulage sector; the forklift truck (1) comprises:
- a tractor unit (2) fitted with a frame (7) and driving and control devices (9, 10) that can be operated by a driver;

- a device (3) for the handling of loads comprising in its turn of a portal (12) that is mainly vertical and connected to said frame (7); a first slide (13) fitted with support devices (4, 4*) for the loads and a second slide (16*), in which both slides (13, 16*) are connected to the said (12) portal; first actuator devices (18) suitable for performing the sliding along a first direction (Y) substantially vertical of the first slide (13) to allow the raising and the lowering of the loads along the first direction (Y); second actuator devices (20) for implementing the sliding of the second slide (16*) along a second direction (X) substantially horizontal; and third actuator devices (21) that allow the rotation of the portal (12) from a work position where the portal (12) is substantially vertical and at right angles to the frame (7) to a bent position where the portal (12) is coplanar with the frame (7), and vice versa;
the forklift truck is characterised by the fact that the portal (12) is finished off by two side appendages (16) fixed to two lateral struts (15) and several crossbeams (17) to strengthen said portal; wherein said several crossbeams (17) support said first actuator devices (18) and wherein said second actuator devices (20) are directly connected at a front end to a lower crossbeam (17*) of the portal (12), while at a rear end to the frame (7) ; the second slide (16*) comprises side arms (23), in their turn connected at one of their ends to a rear element (24) which comprises a side wall (25) in which a gap is included to allow said rear element (24), and consequently the entire second slide (16*), to slide without interfering with said second actuator devices (20), said third actuator devices (21) are connected at a front end to the lower crossbeam (17*) and at its rear end to a side of the rear element (24) such that even when the portal (12) is completely bent, said third actuator devices (21) are alongside said second actuator devices (20), without overlapping, in such a way as to optimise the overall bulk.
Forklift truck according to claim 1, wherein the said third actuator devices (21) comprise a hydraulic actuator (21).
Forklift truck according to claim 1 or 2, wherein the portal (12) is hinged to the second slide (16*) and swivels around a first rotation axis (A2) between the work position where the portal (12) is substantially vertical and at right angles to the frame (7) and the bent position where the portal (12) is coplanar to the frame (7), and vice versa.
Forklift truck according to one of the preceding claims, wherein the load support devices (4, 4*) swivel around a second axis (A1) of rotation between a work position where the load support devices (4, 4*) are arranged substantially at a right angle to the portal (12) and a rest position where the means (4, 4*) of support of the loads are coplanar with the portal (12), and vice versa.
Forklift truck according any preceding claims, wherein the portal (12) comprises a number of rear protruding appendages (22) connected to a lower crossbeam (17*) and hinged to the second slide (16*).
Forklift truck according to claims 3 and 5, in which each appendage (22) swivels around a first shared axis (A2) of rotation to allow a rotation of around 90° of the portal (12), from a work position in which the portal (12) is substantially vertical and at right angles to the frame (7) to a bent position where the portal (12) is coplanar to the frame (7), and vice versa.
Forklift truck according to one of the preceding claims, in which the second slide (16*) comprises a number of appendages (16) coupled to the portal (12) and wherein the side arms (23) slide inside respective guides (19) of the frame (7).
Forklift truck according to any of the preceding claims, wherein the frame (7) is connected at one of its rear ends to a compartment (8) made in such a manner as to house within it the engine unit fitted with a fuel tank, an electronic control unit and a control panel (9) comprising several levers (10) for the command of the forklift (1) truck itself.