WO2009104209A1

WO2009104209A1 - Self-propelled vehicle for transporting materials

Info

Publication number: WO2009104209A1
Application number: PCT/IT2008/000114
Authority: WO
Inventors: Dante Fracca
Original assignee: Dante Fracca
Priority date: 2008-02-20
Filing date: 2008-02-20
Publication date: 2009-08-27

Abstract

A self-propelled vehicle (10) wherein, during the phases of lifting, transporting and lowering a load (CH), the perpendicular projection of the centre of gravity of the load (CH) on a vehicle/ground plane of contact always falls within an area (AR) defined laterally, posteriorly and anteriorly by tracks (12, 13). Moreover, the tracks (12, 13) are selected so as to reduce the specific pressure in the vehicle/ground interface, and to keep the underside of the frame structure (14), and/or of the lifting assembly (21) as far from the ground (GR) as possible, so that the vehicle (10) is suitable to move off -road on uneven, not compacted, not paved, not cemented or not asphalted surfaces.

Description

SELF-PROPELLED VEHICLE FOR TRANSPORTING MATERIALS

TECHNICAL FIELD

The present invention relates to a self-propelled vehicle for transporting materials. BACKGROUND ART

As is known, vehicles called "forklifts" are used to handle pallets and other loads. Said vehicles comprise a power unit provided with wheels having a fork lifting device at the front.

For example, to move a pallet the operator controls the forks of the forklift, lowering these until they are almost down to the ground, and then moves the forklift towards the pallet so that the forks are inserted into holes in said pallet under the load. The operator then uses the controls to raise the forks, which, in turn lift the pallet and the materials loaded onto it.

The operator then moves the forklift with the pallet; next, the forks are lowered so that the load comes to rest in the place where the contents of the pallet are to be used.

Forklifts are an efficient means of transporting loads. However, since the forks of normal wheeled forklifts are in a cantilevered position in "relation to the mass of the rest of the vehicle, any mass, that is loaded to be transported leads to the creation of a moment that tends to raise the rear part of said vehicle (which pivots about the front part) ; said moment must be counterbalanced by the mass of said vehicle. Therefore, the size of the loads that a given forklift can transport depends on the overall mass of said forklift. In other words, the greater the counterbalancing mass of the vehicle, the greater the load that can be transported.

For these reasons, the forklifts used for transporting heavy loads, for example of tiles, must be stable and heavy, but these are also large, difficult to transport and expensive. As is known, the cost of a vehicle is actually often proportional to its weight.

As mentioned above, the problem of the weight refers to the fact that on conventional forklifts the projection of the centre of gravity of the load is usually outside the supporting base.

A type of self-propelled or hand-driven vehicle, commonly known as a "pallet truck" , is known in the prior art, in which the projection of the centre of gravity of the load is within the supporting base of the vehicle on the ground.

Conventional wheeled pallet trucks, however, have difficulty moving on uneven, rough and rugged terrains. It is often completely impossible for conventional pallet trucks to move if the ground is not well compacted, paved, cemented or asphalted given the shape of their wheels and the small distance of the vehicle from the ground.

With the pallet trucks that are normally used, considerable pressure is generated on the areas of the wheels that come into contact with the ground. Moreover, on rough terrain the underside of the pallet truck may even scrape against the ground with all the obvious negative repercussions. The drawback of this machine, for the reasons described above, is therefore that it is completely- impossible for it to move on ground that is not compacted, paved, cemented or asphalted. DISCLOSURE OF INVENTION The main purpose of the present invention is therefore to overcome the drawbacks described above with a self-propelled vehicle that is relatively light, very safe, stable and reliable, suitable to move on any type of terrain even if it is not compacted, paved, cemented or asphalted.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the attached drawings, illustrating a non- limiting embodiment thereof, in which: - figure 1 shows a three-dimensional overall view of a vehicle that, by way of example, is tracked (with „

the forks partially raised) according to the present invention;

- figure 2 shows a plan view of the tracked vehicle in figure 1; - figure 3 shows the tracked vehicle (with the forks completely lowered) shown in figures 1, 2 during its approach to a load;

- figure 4 shows a phase in which actual loading of the load onto the self-propelled vehicle shown in figures 1, 2, 3 starts (the forks are still lowered) ; and

- figure 5 shows the load fully loaded onto the self-propelled vehicle shown in figures 1, 2, 3, 4 (the forks have now been raised from the ground) . BEST MODE FOR CARRYING OUT THE INVENTION

In the attached drawings, number 10 indicates a self-propelled vehicle according to the invention.

The self-propelled vehicle 10 comprises a power unit 11, which in turn comprises traversing means suited to move on rough terrains, consisting by way of example of a pair of tracks 12, 13 on which a frame structure 14 is mounted to support an engine 15 provided with a fuel tank 16, a control panel 17 comprising a plurality of levers 18 suited to send the commands necessary to move the self-propelled vehicle 10 and to operate the various devices (see below) . A lifting assembly 21 to lift a pair of lifting and transporting forks (FR) is also attached to the frame structure 14.

According to an alternative embodiment which is not illustrated the tracks can be rigid or with a frame structure jointed in one or more points. The track rollers can be of the fixed or pivoting or cushioned type.

According to an alternative embodiment which is not illustrated, wheels can be used instead of the tracks. Said wheels must be of a suitable size in order to fulfil the dual purpose of distributing as much of the weight of the load as possible over a wide surface to reduce the pressure in the wheel/ground interface, and of keeping the underside of the frame structure 14 and/or of the lifting assembly 21 as far from the ground as possible in order to avoid any interference between the vehicle and the ground.

Besides an internal combustion- type engine 15, an electric motor assembly (not illustrated) self-propelled by storage battery systems or by the mains can be advantageously used.

The tracks 12, 13 can be made of metal, or be rubber-tired, or can be made of metal and rubber- tired.

More in detail, it is important to note that each track 12, respectively 13 is supported by a respective side carriage (CRl) , (CR2) . According to other embodiments of the present invention which are not illustrated, instead of the tracks 12, 13, the traversing means consist of at least four wheels, which, thanks to their characteristics or to the method used to mount said wheels on the side carriages or on the frame structure 14, enable the vehicle to move even on surfaces that are not compacted, not paved, not cemented or not asphalted.

Moreover, as described more fully later on in this document, each side carriage (CRl) , (CR2) is provided with a corresponding arm (BRl) , (BR2) mechanically- linking it to the frame structure 14; moreover, each arm (BRl) , (BR2) can be provided with a respective sideshift device (DSPl) , (DSP2) (not shown in the attached drawings) suited to shift it sideways to alter the supporting base of the vehicle (see below) .

The traversing means 12, in this case a track, envisages a respective front extremity 12a and a respective rear extremity 12b with respect to the "forward" direction of travel of the vehicle 10 identifiable as the outermost points of contact between the ground and said traversing means; similarly, in the traversing means 13 (also in this case a track) a respective front extremity 13a, matching the front extremity 12a of the other track 12, and a respective rear extremity 13b, in turn matching the rear extremity 12b of the track 13 can be observed.

The rear part of the power unit 11 (next to the control panel 17) is provided, in a known way, with a platform 19 on which an operator (not shown) stands and makes the self-propelled vehicle 10 move forward and/or operates the various devices using the levers 18.

The control panel 17 is also provided with a handle 20 which the operator can grip using one hand, while using the other to drive the self-propelled vehicle 10 using the levers 18.

As illustrated in the particular embodiment in figure 1, an area (AR) is defined on the ground/vehicle plane of contact, between the front extremities 12a, 13a and rear extremities 12b, 13b of the traversing means, inside which the lifting assembly 21 for lifting a pair of lifting and transporting forks (FR) is arranged.

In other words, the area (AR) is defined anteriorly by the two front extremities 12a, 13a of the tracks 12,

13, posteriorly by the two rear extremities 12b, 13b of the tracks 12, 13 and laterally by inside faces 12c, respectively, 13c of said tracks 12, 13.

Moreover, the transverse length (Ll) of the area

(AR) is essentially equal to the distance between the inside faces 12c, 13c of the tracks 12, 13 (figure 2), and its longitudinal length. (L2) is essentially equal to the distance between the extremities 12a, 13a and the extremities 12b, 13b of said tracks 12, 13.

As illustrated particularly in figures 1, 2, the area (AR) contains the lifting assembly 21, the pair of forks (FR) and the projection^' of the centre of gravity (not shown) of the load (CH) supported thereby.

The lifting assembly 21 is of the hydraulic type and is not described in detail in that it is known in this type of application. The load lifting assembly can also be of the mechanical, manual, electric or pneumatic type. It may be provided with a system for shifting the forks (FR) sideways and/or a system for adjusting the tilting angle of said forks (FR) .

Moreover, the lifting assembly 21 can only lift the forks (FR) but cannot translate them horizontally. According to one embodiment which is not illustrated, the lifting assembly 21 lifts the load (CH) in such a way that the value of the length (Ll) of the distance between the tracks 12, 13 can be reduced as much as possible by moving the devices (DISPl) and (DISP2), thus limiting the machine's maximum overall dimensions (ING) to the width of the load being transported (L3) .

Figure 3 shows the operation in which the vehicle 10 approaches a load (CH) of any kind, loaded on a pallet (PLT) .

For example, the load (CH) may be a load of bricks, of firewood, crates of tomatoes, crates of apples, etc.

During this approach phase the forks have been lowered so as to almost touch the ground (GR) .

Once the load (CH) has been loaded, the lifting assembly 21 lifts it to a height varying from a few centimetres to several metres .

To enable the forks (FR) to be inserted beneath the load (CH) the overall width (L3) of the load (CH) is less than the transverse length (Ll) of the area (AR) . For this reason self-propelled vehicles 10 should preferably be designed with large transverse dimensions; this allows very wide pallets (PLT) and/or crates and/or loads (CH) (i.e. with large (L3) values) to be loaded and increases the overall stability of said self- propelled vehicles 10.

According to one embodiment which is not illustrated, each sideshift device (DSPl) , (DSP2) can be used to move the respective carriage (CRl) , (CR2) towards/away from the respective fork (FR) . This, for instance, means that, after loading a load (CH) easily (thanks to the difference between (Ll) and (L3)), the overall width (ING) of the vehicle 10 (figure 2) can be reduced to allow the loaded vehicle 10 to pass, for example, through a narrow opening (not illustrated) .

Moreover, the lifting assembly 21 for lifting the pair of forks (FR) can be provided with a gyroscopic system (not shown) by means of which, even if only one side carriage (CRl) , (CR2) , is lifted, the pallet (PLT) and the load (CH) it carries are not tilted, but are supported by the forks (FR) in an essentially horizontal position.

To contrast the natural tilting of the load (CH) on rough terrains, the same result can be achieved by using independently controlled variable length sideshift devices (DISPl) , (DISP2) . Said devices (DISPl) , (DISP2) must have a direction of movement that is on a slope with respect to the horizontal. When one of the two devices (for example, (DISPl) ) is extended in the direction on a slope with respect to the horizontal, the carriage (CRl) connected to it is lowered with respect to the opposite carriage (CR2) . Said lowering enables it to rest on a sloping terrain while the frame structure 14 remains horizontal .

The operator can stand on the platform 19, or sit on a seat (not illustrated) , or accompany the self- propelled vehicle from the ground, walking next to the control panel 17 or controlling it using known wire or remote control systems .

Moreover, the vehicle 10 according to the present invention can be provided with a mechanical arm (not illustrated) , which rests on the upper surface (CH*) of the load (CH) so as to push said load (CH) against the forks (FR) increasing the stability of the load (CH) during transport and blocking said load (CH) .

The self-propelled vehicle according to the present invention has the following advantages:

- possibility of moving off-road on surfaces that are not compacted, not paved, not cemented or not asphalted; reduced vehicle weight; the relatively light weight of the self-propelled vehicle according the present invention results in a considerable reduction in the overall cost of producing the actual vehicle and considerable advantages in terms of transportability for example on vehicles provided with loading ramps and/or vehicles with cranes or construction site cranes or helicopters ; the load and/or the actual vehicle cannot overturn as the perpendicular projection of the centre of gravity of the load on the ground/machine supporting base is always (at all times during loading from the ground, transporting and unloading onto the ground) inside an area defined laterally by the carriages supporting the traversing means (wheels, tracks, etc.) of said vehicle; - possibility of combining the use of automatic load- levelling systems (for example through the use of at least a gyroscope) even when the vehicle moves on uneven terrains that are not flat.

- possibility of adapting the overall width of the vehicle to that of the spaces, openings, distances between rows, etc. through which the self-propelled vehicle must pass.

Claims

CLAIMS 1. Self-propelled vehicle (10) comprising:

- a power unit (11) provided with a frame structure (14) and traversing means (12, 13) ; - power, control and command means (15, 17, 18) suited to be operated by an operator to move the self- propelled vehicle (10) and/or use any tools; and

- means (21, FR) for. supporting and lifting a load (CH) ; self-propelled vehicle (10) characterized in that, during the phases of lifting, transporting and lowering the load (CH) , the perpendicular projection of the centre of gravity of said load (CH) on a vehicle/ground plane of contact is always within an area (AR) defined laterally, posteriorly and anteriorly by said traversing means (12, 13) . and in that said traversing means (12, 13) are selected so as to reduce the pressure in the vehicle/ground interface, and keep the underside of the frame structure (14) and/or of the supporting means (21 (FR)) as far from the ground (GR) as possible, so that said power unit (11) is suited to move off-road on surfaces that are not compacted, not paved, not cemented or not asphalted.

2. Self-propelled vehicle (10) according to claim 1, characterized in that it is provided with side carriages (CRl, CR2) bearing respective traversing means (12, 13) ; each side carriage (CRl, CR2) being provided with a corresponding arm (BRl₇ BR2) mechanically linking it to the frame structure (14); moreover, each arm (BRl, BR2) is provided, in turn, with a respective sideshift device (DSPl) , (DSP2) , whereby the respective carriage (CRl, CR2) is moved towards/from respective loading and lifting means (FR) .

3. Self-propelled vehicle (10) according to any one of the previous claims, characterized in that said means (21, FR) for supporting and lifting a load (CH) are provided with a gyroscopic system whereby the load (CH) being carried thereby is not tilted, but is always held in an essentially horizontal position.

4. Self-propelled vehicle (10) according to any one of the previous claims, characterized in that it is also provided with a mechanical arm that, in use, rests on the upper surface (CH*) of the load (CH) so as to increase the stability of said load (CH) during transport and block it .

5. Self-propelled vehicle (10) according to any one of the previous claims, characterized in that the operator stands on a platform (19), or sits on a seat, or accompanies the self-propelled vehicle (10) from the ground, walking next to the control panel (17) or controls it using a wire or remote-control system.

6. Self-propelled vehicle (10) according to any one of the previous claims, characterized in that it is provided with tracks (12, 13) ; the tracks (12, 13) being rigid or with a frame structure jointed in one or more points; the rollers of the tracks (12, 13) being of the fixed or pivoting or cushioned type.

7. Self-propelled vehicle (10) according to claim 6, characterized in that said tracks (12, 13) are made of metal, or rubber-tired, or metal and rubber-tired.

8. Self-propelled vehicle (10) according to any one of the claims from 1 to 5 , characterized in that it is provided with wheels suitable to move off -road on rough surfaces that are not compacted, not paved, not cemented or not asphalted.

9. Self-propelled vehicle (10) according to any one of the previous claims, characterized in that the engine (15) is an internal combustion engine, or of the electric type self-propelled by storage battery systems or the mains .