WO2020044064A2

WO2020044064A2 - Lightweight and small size forklift

Info

Publication number: WO2020044064A2
Application number: PCT/GR2019/000059
Authority: WO
Inventors: Theodore DESSOS
Original assignee: Dessos Theodore
Priority date: 2018-08-27
Filing date: 2019-08-26
Publication date: 2020-03-05
Also published as: GR20180100396A; WO2020044064A3

Abstract

Forklift truck, the web (25) of which is able to move horizontally on the vehicle and to carry the cargo on its deck. The vehicle, apart from the cargo lifting pins (26), (27), is also equipped with a pair of supporting pins (61), (62) which descend down to the ground and compensate the overturning moment developed to the vehicle during the cargo lifting procedure. These supporting pins forks may be foldable on the front of the vehicle, or be underneath the vehicle and be properly lowered and extended forward when the cargo is lifted. To further reduce the dimensions of the vehicle, the vehicle's cab may be removed and the vehicle can be operated / driven from a control room, wirelessly connected with the vehicle. The mast (25) is capable to rotate 90 degrees in order to allow the cargo handling from the side of the vehicle.

Description

Lightweight and small size forklift

Forklifts are widely used, both in industry and storage facilities, in order to transfer and store cargos, which are usually placed on appropriate pallets. There are many types of forklifts, but generally, the typical forklift (12) consists of - as it is briefly shown in the simplified drawing 1 - the main body (10) with the wheels (11) and its other components, (mechanical / hydraulic systems, steering and control systems etc.), the vehicle control cab (30), the typical mast (20) on which the base of the cargo lifting pins (22), (23) move vertically by mechanical / hydraulic or electrical means. Said cargo lifting pins (22), (23) can also move horizontally and independently on the base of the pins so that they can be adjusted each time to the suspension pockets of the cargo to be transported. Optionally, the mast (20) can be tilted by means of suitable equipment - and according to the prior art - for better handling of the cargo. There are many ways to move the forks (22), (23) and to handle the vehicle in general, but since both the types and the operation modes of these forklift trucks are well known, there is no need for further detailed description thereof. Due to the operation principle of the forklift trucks, when a heavy cargo is lifted / transported, a strong overturning moment is developed to the vehicle around its front wheel axis, which is countered by the vehicle's own weight. Since the weight of the vehicle is usually not enough for this, additional counterweight (35) is placed on the rear of the vehicle and also the length of the vehicle is increased on purpose, in order to maximize the counter moment (which is necessary for the compensation of the overturning moment developed by the cargo lifting). In this way, however, the vehicle becomes too heavy and lengthy. For example, the case of a standard (ie commercially available) forklift truck of 5 tons capacity, is reported, with the center of gravity of the cargo been just 0.6 m from the front surface of the vehicle mast. For the compensation of the overturning moment, this forklift is designed to have a total length of about 4.7 m and a weight of about 7.5 tons, while during the lifting and transporting of the 5 tons cargo, the load on the front axle of the vehicle rises to 11.2 tons, ie more than double the nominal lifting load. Also, the gross center of gravity of the vehicle (ie the center of gravity of the vehicle weight and the 5 tons cargo) is only 26 cm from the front axle of the wheels, with the relevant consequences regarding the stability of the vehicle during its movement. As it is obvious, the situation becomes worse if the vehicle is called to carry a cargo of greater width, or greater weight. As a result, the weight and the cost of the vehicle are significantly increased, and its flexibility is greatly reduced due to its long length. It is noted that in many forklift models the wheels are rotated up to 90 degrees so that the vehicle can rotate about its vertical axis or move vertically in respect to its conventional direction of travel, in order to enter in relatively narrow warehouse isles and deposit or receive a heavy cargo. However, if the length of the vehicle is 4.5 to 5 meters, then the capability of the vehicle to rotate its wheels by 90 degrees and move vertically in respect to its conventional direction of travel, ceases to be meaningful.

The above mentioned drawbacks are minimized, by reducing the distance of the center of gravity of the cargo from the axle of the front wheels of the vehicle, thereby reducing the overturning moment.

If the center of gravity of the cargo is placed between the axles of the wheels of the vehicle, meaning within the vehicle's polygon of stability, then, obviously, no overturning moment is developed and consequently no counterweights are required. In this way, both the weight and the length of the vehicle can be reduced considerably, resulting to the reduction of the construction and operating cost of the vehicle and increasing its versatility.

Several applications (both commercial and patent) have been developed in accordance to the above mentioned, such as:

1) Lifting and transporting the cargo is carried out with the cargo placed between the front and the rear wheel axles. In this case, the front wheels of the vehicle extend forward in the form of cantilever, right and left of the cargo as generally seen in EP1481942B1. Disadvantages of this design are that it can handle only relatively small width cargos, and that it is very difficult or even impossible to handle cargos placed on decks.

2) The forklift is supplied with telescopic arms, located on the front of the vehicle and extending to the right and left respectively, and to the foot of each arm descends to the ground and supports the vehicle, increasing the dimensions of its stability polygon. According to this design, however, in each laterally extending telescoping arm, both bending and torsional stresses are developed. The vector sum of these stresses is very high and it strains the arm so much that both the arm and its supporting structure have to be strong enough, in order to withstand this very intense load. Also, the deformation of the arms due to the aforementioned loads is intense, resulting in the remarkable (and undesirable) tendency of the vehicle to be deformed. In order to deal with the foregoing, the arms are required to be heavy-duty and bulky, whereas in these constructions the supporting legs do not extend far forward, so the overturning moment is not limited too much, resulting to poor final result (technically and economically). Also, the center of gravity of the cargo, is not usually within the vehicle's polygon of stability (including also the above-mentioned supporting feet), thereby developing an overturning moment on the vehicle. There is still a limit on the width of the cargo carried.

) The option of the forklift to have a horizontally moving mast, so that the cargo is deposited on the vehicle after been lifted, so that it can be safely transported. As illustrated in simplified drawing 2, the mast (25) together with the pins (26), (27) and their base thereof, can be moved horizontally on the vehicle (12), preferably along fixed rails (50), so that the cargo, being suspended by the pins (26), (27) moves on the vehicle deck and it either remains suspended by the pins (26), (27), or it is laid on the body of the vehicle (12), through the slight downward movement of the pins (26), (27). The end positions of the web (25) are the front (201) for picking up or depositing the cargo and the rear (202) (shown in dotted line) for carrying the cargo. Again, however, during the lifting or depositing phases of the cargo, an overturning moment develops, thus setting clear limits on the weight and size of the cargo that the vehicle can handle.

In summary, it seems that no low cost and small size forklift exists in the market, capable to handle a cargo without an overturning moment is developed, either during the lifting / depositing of the cargo, or during the transportation of the cargo.

The forklift truck according to the present invention, ensures that the overturning moment is totally absent both during the transportation or the handling of the cargo. As a result, this vehicle can be lightweight and small in size, that is to say, it has a low manufacturing and operating cost, but it can also be versatile when moving within narrow warehouse isles, especially if it is equipped with wheels capable to rotate up to 90 degrees around their axis. More specifically, during the transfer phase, the center of gravity of the cargo is located between the axles of the wheels of the vehicle, resulting in the safe cargo transportation. In addition to the pair of lifting fork pins, said forklift vehicle is also equipped with a second fork (pair of pins) for supporting the vehicle on the ground (or a deck of any kind) so that, during the lifting or the depositing of a cargo, the overturning moment is fully and safely compensated by the said supporting fork.

Brief description of figures.

Figure 1 shows, in a simplified way, a typical forklift truck. Figure 1 a shows the basic parts of the vehicle, while figure 1 b shows a typical vehicle capable to move the cargo on the vehicle body, meaning within the stability polygon.

Figure 2 shows, in a simplified way, the basic parts of a forklift which, according to the present invention, is equipped with an additional fork for supporting the vehicle against overturning.

Figure 3 shows, in a simplified way, the cargo lifting / depositing pins as well as the supporting pins, according to the certain design that they will nest in each other. These pins are shown both during the vehicle traveling phase (figure 3a) and during the cargo lifting / depositing phase (figure 3b). Figure 3c shows the cross - section of the forks during the cargo lifting / depositing phase.

Figure 4 shows, in a simplified way, the cargo lifting / depositing pins as well as the supporting pins according to the certain design that these they are placed next to each other. These pins are shown both during the vehicle traveling phase (figure 4a) and during the cargo lifting / depositing phase (Figure 4b). Figure 4c shows the cross - section of the forks during the cargo lifting / depositing phase.

Figure 5 shows, in a simplified way, the procedure for lifting a cargo from the ground, according to the certain design that each cargo lifting / depositing pin “nests” into the respective supporting pin.

Figure 6 shows, in a simplified way, the supporting pins being in the extended state (Figure 6b) or folding state (Fig. 6a). In this figure, there are also shown the cross - sections of a cargo lifting / depositing pin and the respective supporting pin during the cargo lifting / depositing phase, according to various alternative designs of the forks. (Figure 6c).

Figure 7 shows, in a simplified way, the procedure for lifting a cargo from the ground, according to the certain design that the supporting pins are located and moving back and forth, on a frame which is capable of moving upwards and downwards along an arcuate orbit by means of articulated arms and hydraulic cylinders.

The forklift truck (12) according to the present invention, shown in figure 2, is equipped with the typical parts of a conventional forklift, namely the main body (17) with the wheels (16) and its other components, (such as mechanical / hydraulic systems, steering and control systems, etc.), the vehicle control cab (31), the typical mast (25) on which the supporting structure of the cargo lifting pins (26), (27) moves vertically by mechanical or hydraulic means, etc. Said cargo lifting pins (26), (27) can additionally move horizontally and independently on their supporting structure, so as to fit to the lifting pockets of the cargo to be lifted. Moreover, according to the prior art, the mast (25) together with the cargo lifting pins (26) (27) and their supporting structure thereof can be moved horizontally on the vehicle, preferably along fixed rails (50) on the vehicle (12) so that the cargo which is suspended on the pins (26), (27) is moved on the vehicle and either it remains suspended on the pins (26), (27) or it is deposited on the vehicle body (17), via the slight lowering of the pins (26), (27). The limit positions of the mast (25) are the front one (201) for lifting and depositing the cargo and the rear one (202) (shown in Figure 2 with dotted line) for carrying the cargo. The cargo lifting pins (26), together with their supporting structure, need in many cases to lower too much (i.e., up to the ground level) in order to lift or deposit the cargo. However, since the said mast (25) on which the aforementioned supporting structure of the pins (26), (27) is placed moves horizontally, the available options are:

• The said supporting structure of the cargo lifting pins has sufficiently increased height, so that, when it is located in its lowermost position it is still coupled to the vehicle mast (25) and may effectively transfer to the mast the moment developed by the cargo that is lifted.

• There are suitable guides / rails in the front side of the vehicle, shaped in a form similar to the one of the mast (25). The upper side of said guides / rails extends up to the lower part of the mast (25), and the said guides / rails are aligned with the mast (25), when the mast is at its front position (201). In this way, as the pins (26), (27) are lowered, their supporting structure is gradually engaged to the said guides / rails. Both the lower part of the mast (25) and the upper part of the guides / rails are locally widened, so that when the supporting structure of the pins (26), (27) moves vertically, it is smoothly engaged from the mast (25) to the guides / rails or vice versa.

It is emphasized that the above-mentioned configurations are purely indicative without harming to generality, as any other known modulation method concerning the attachment of the pins (26), (27) to their supporting structure and the attachment of the said supporting structure to the mast (25) can also be adopted.

Additionally, the vehicle (12) preferably has wheels (16) capable of rotating about their vertical axis up to 90 degrees, in order to increase the flexibility / versatility of the vehicle, since the vehicle (12) is lightweight and small in size. This is because its weight and its length are determined only by the size and the weight of its functional components, due to the fact that no counterweights and no artificially increase of the length of the vehicle (12) are necessary any more, since overturning moment actually does not exist.

The innovative feature of the forklift truck according to the present invention is that, as shown in Figure 2, said vehicle (12) also has a second pair of pins (61), (62) for supporting the vehicle on the ground or on a deck, so that the overturning moment developed to the vehicle when a cargo is lifted, is fully and safely compensated. Said second pair of supporting pins (61), (62) is mounted on its own supporting structure, which can be moved vertically, along a plane located behind the corresponding plane of the supporting structure of the cargo lifting pins (26), (27) and regardless of its movement. Said vertical movement of the supporting structure of the pair of supporting pins (61), (62) is carried out along respective guides, which are fixed to the body of the vehicle (12). In this way, the supporting pins (61), (62) can be moved vertically and reach low to the ground. The vertical portions of the supporting pins (61), (62) move on a plane which is located behind the plane on which the vertical portions of the cargo lifting pins (26), (27) move, (i.e. , the vertical portions of the supporting pins (61), (62) move on a plane closest to the center point of the vehicle) so that the supporting structure of the pins (26), (27) can be moved comfortably in the intermediate space. It is emphasized that the aforementioned configuration is purely indicative, without impairment of generality, as any other known modulation of the connection of the forks with their supporting structure and the connection of the supporting structure with the body of the vehicle can also be adopted. Figure 4a shows, in a simplified way, the positions of the supporting pins at their upper position (i.e. in the position they have when the vehicle is moving) and figure 4b shows the positions of the pins at their lower position, i.e. in the position that they are during the cargo lifting or cargo depositing. Figure 4c shows the cross - section of the pins when they are in the cargo lifting phase. The aforementioned additional pins (61), (62) can protrude in front of the vehicle (12) to the same point with the cargo lifting / depositing pins (26), (27), or, alternatively, have a shorter length, since their purpose is just to support of the vehicle (12), meaning that they may just protrude sufficiently behind the load center of gravity of the cargo and not necessarily cover the entire width of it. Said additional pins (61), (62) can also move horizontally on their supporting structure to accommodate the lifting pockets of the cargo to be lifted.

When lifting or depositing the cargo, the supporting pins (61), (62) are adjacent - and very close - to the cargo lifting pins (26) (27), at about the same horizontal plane with them. The said supporting pins (61), (62) may be placed, either to the right and to the left of the cargo lifting pins (26) (27), or one of them being between the cargo lifting pins (26) (27) and the other out of them. Fig. 4c shows the cargo lifting pins (26) / (27) and the respective supporting pins (61) / (62) in the phase of cargo lifting. In this manner, however, the required width of the lifting pockets of the cargo to be transported has to be greatly increased, so that all pins (26), (27) (61) and (62) may insert in said pocket. In order to address this problem, a special design is implemented. According to this design, each one of the vehicle supporting pins (61), (62) moves along the same vertical plane with the corresponding cargo lifting pin (26), (27). The exact alignment of each supporting pin (61) / (62) with the corresponding cargo lifting pin (26) / (27) is realized by means of suitable guides. The cross section of each supporting pin (61), (62) is not of a rectangular shape, as is usually happens with the cross-section of typical pins, but in the form of an upside - down“flattened pi” with the opening at the top of its cross-section, as shown in Figure 3c. That is, the cargo lifting pin (26), the cross section of which is rectangular in shape, descends and“nests” into the respective supporting pin (61) of the vehicle. (The same happens with the pins (27) and (62)), so that the overall dimensions of the fork system does not increase too much, making it easy to insert into the lifting pockets of the cargo. Figure 3 shows the cargo lifting pins and the supporting pins as above. These pins are shown both during the vehicle traveling phase (figure 3a) and during the cargo lifting (or depositing) phase (figure 3b). Figure 3c shows the cross - section of the forks during the cargo lifting phase.

The cross-sectional dimensions of each supporting pin (61) / (62) are suitably selected such that the bending resistance modulus (W) of the cross-section (at each point along it) is capable to withstand the bending moment developed to it. Preferably, (for safety purposes), the bending resistance modulus (W) of the cross section of each supporting pin (61) / (62), at each point along it, is advised to be may be greater than the corresponding bending resistance modulus (W) of the cross-section of the corresponding cargo lifting pin (26) / (27) so that in case of failure, due to overloading, the cargo lifting pins will fail, and not the supporting pins. In addition, in the final design of the cross-sectional dimensions of each supporting pin, the inertia modulus (J) of the cross-section of the pin should be high enough in order to maintain the fork deformation within acceptable limits.

Various other design approaches regarding the configuration of the cargo lifting pins (26) / (27) and the supporting pins (61) / (62) of the vehicle can be adopted, as shown in the sectional views of Figure 6c, i.e. the cross section of each the first ones is shaped as a "flattened pi", while the cross section of each one of the second ones is shaped rectangular; or the cross sections of all of them are shaped as "flattened pi" (without necessarily equal width sides) and complement each other without the centers of gravity of all the cross- sections (not necessarily) be on the same vertical line; or all of them are "L" shaped and complemented; or one is " flattened pi" shaped and the other "m" shaped and complement each other, etc. Furthermore, all four pins (supporting and lifting) may be of rectangular cross section (or any other form) and each cargo lifting pin (26) / (27) may simply be adjacent next to the respective supporting pin (61) / (62) that is, without“nesting” into each other.

For lifting the cargo from the ground, the following procedure is followed, as shown on Figure 5, (in the case where the cargo lifting pins (26) "nest" in the respective supporting pins (61) 62), according to Figure 3):

1) The vehicle (12) approaches the cargo (40) and the mast (25) together with the cargo lifting pins (26), (27) moves to its front position (201). The supporting pins (61) / (62) of the vehicle are still at the travelling position, i.e. on the front of the vehicle and at a sufficient clearance from the ground, (as required for the vehicle traveling procedure). (Figure 5a).

2) The lifting pins (26), (27) descend, meet the supporting pins (61) / (62) of the vehicle and each one of them“nests” into the respective supporting pin (61) / (62). All the pins together continue to move downwards to the cargo lifting position, ie slightly above the ground. (Figure 5b). 3) The vehicle (12) approaches the cargo (40), and all the pins (26), (27), (61), (62), by appropriate maneuvers of the vehicle (12), inset into the lifting pockets of the cargo (40). (Figure 5c).

4) The vehicle supporting pins (61) / (62) move slightly downwards until they touch the ground and support the vehicle (12) and then they are secured in place, that is to say they are locked in this position by mechanical means, or hydraulic means, or in any other way. (Figure 5d).

5) The lifting pins (26), (27) move upwards and carry the cargo (40) to a point above the top (i.e. the deck) of the vehicle (12). (Figure 5e).

6) The mast (25) moves horizontally on the vehicle to the position (202), transferring the cargo (40) onto the vehicle (12). (Figure 5f).

7) The vehicle supporting pins (61) / (62) move up to their standby position and then the vehicle (12) transfers the cargo (40) to its destination. (Figure 5g).

For depositing the cargo on the ground, the reverse procedure is followed.

If the cargo (40) to be handled has been placed on a deck of any kind, (truck deck, rack of a storage cabinet, etc), the above mentioned procedure is followed, except that when the vehicle (12) approaches the cargo (40), the pins (26), (27 ) are at the elevation of the cargo lifting pockets (and opposite to them), while the supporting pins (61), (62) are slightly above the ground, so they enter below the truck deck, or below the relevant rack of the cabinet in order to touch the ground (or the lower rack of the cabinet) and support the vehicle.

In the case where the cargo lifting pins (26), (27) are not "nesting" in each other but are placed next to each other (according to figure 4), procedures similar to those described above are followed.

According to the above mentioned, the cargo lifting pins (26), (27) as well as the vehicle supporting pins (61) (62) protrude therein, thereby increasing the length of the vehicle and reducing its versatility, especially if the vehicle is required to enter into narrow warehouse corridors by rotating its wheels by 90 degrees.

The above issue is addressed in the following ways:

1) The supporting pins (61) / (62), in addition to the aforementioned movement capabilities, can also be folded to the front of the vehicle (Figure 6). More specifically, each one of the said pins rotates about a vertical axis passing through its vertical portion, and which shaft is mounted on bearings located on the base of these pins. In Figure 6, the forks (61) / (62) are shown in an extended state (Fig. 6b) or folded state (Fig. 6a). Figure 6 refers to the designing option in which the cargo lifting pins (26) / (27) and the supporting pins (61) / (62) are adjacent to each other. The same is also valid for the (generally preferred) design option, in which each one of the cargo lifting pins (26) / (27)“nests” into the corresponding supporting pin (61) / (62). In both of the above-mentioned design options, during folding, the two supporting pins (61), (62) are preferably not at the same plane, but one of them (61) is further back and lower than the other (62), so that folding is feasible, regardless of the position of one pin (61) in respect to the other (62). In addition, the horizontal portion of the back pin (61) is preferably slightly longer than that of the front pin (62), so that when the pins extend forward, their end points are at equal distances from the front surface of the vehicle. Due to this design feature, the vehicle can enter into narrow warehouse corridors by rotating its wheels by 90 degrees, with the supporting pins (61), (62) in the foldable position and the mast (25) at its rear position (202).

In order to receive a cargo from a deck of any kind, (truck deck, rack of a storage cabinet, etc) the vehicle approaches the cargo (40), and the lifting pins (26), (27) are at the elevation of the cargo lifting pockets (and opposite to them), The supporting pins (61) /

(62) descend to a point just a little above the ground (or slightly above the upper part of the lower rack of the cabinet) and rotate by 90 degrees forward and after this, these two pins (61) / (62) descend a little further until they touch the ground (or at the top of the lower (and preferably empty) rack of the cabin) and support the vehicle. Then, the mast (25) moves forward to its cargo lifting position (201) and the cargo lifting (26), (27) enter into the cargo lifting pockets and lift the cargo. The mast (25) moves (together with the cargo) to its back position (202). The supporting pins (61), (62) move upwards and fold back to their folding position, so that the vehicle is ready to travel. For cargo depositing, the reverse procedure is followed.

) The supporting pins (61) / (62) do not have the familiar "L" shape, but they are straight, horizontally located and their supporting base moves not vertically but horizontally, along a forward-backward direction, while being mounted on a horizontal movable frame which is mounted to the underside of the vehicle. During the vehicle traveling phase, this frame is at its uppermost position, that is, it is either almost in contact with the underside of the vehicle, or“nests” into properly shaped recesses at the underside of the vehicle, providing the necessary clearance from the ground. The assembly of this frame to the underside of the vehicle and its upward and downward movement is realized in one of the following ways:

a) Using (preferably four) articulated arms, via which the frame is capable to move downwards - upwards along an arcuate orbit, maintaining constantly its horizontal orientation during this movement. This movement is realized by means of suitable hydraulic cylinders or other mechanical / electrical / hydraulic components. When the frame is at its lower position (i.e., at the cargo lifting position), the front arms suffer compression load and the rear arms tensile load. Since all arms are almost at vertical direction, the force flow finds its way mainly through them and therefore the residual force flow through the hydraulic cylinders which move the frame is very small, so the stress developed to these cylinders is also very small, resulting in their relatively small diameter and strength requirements.

b) The frame (on which the supporting pins (61), (2) are mounted) moves downwards or upwards along a straight line (and not in an arcuate orbit), along suitable guides / rails which are located on the vehicle (12). Said movement is realized via suitable hydraulic cylinders or other mechanical / electrical / hydraulic elements.

The supporting pins (61) / (62), (which together with their base are mounted on the said movable frame), can move forward in respect to the frame (i.e., to the cargo lifting position) and return back to the vehicle traveling position by means of hydraulic cylinders or other mechanical / electrical / hydraulic components. The (forwards - backwards) movement of the pins (61) / (62) is realized via linear bearings (either sliding or rolling) which are assembled on the said frame. All the above mentioned elements (pins, pin mounting elements, frame, guides, etc.) are suitably dimensioned so that they can stand the stresses developed to them, due to the overturning moments during the cargo lifting procedure. It is noted that during the cargo lifting phase, only transverse loads and bending moments are developed and not loads along the axis of the supporting pins. This means that the hydraulic (or pneumatic) cylinder (s), or any other hydraulic or mechanical or electrical devices which drives the pins to their forward - backward movement may be very small in diameter and capacity, since the work they have to carry out is of very small.

For lifting a cargo from the ground (and in case that the articulated arms are used for the movement of the frame), the following procedure is followed, as shown in Figure 7:

1) The vehicle (12) approaches the cargo (40) and the mast (25) together with the lifting pins (26), (27) are at their back position (202). The supporting pins (61), (62) together with their base and the frame are in the stand-by position, i.e. they are at their back and top positions respectively. (Figure 7a)

2) The mast (25) (together with the lifting pins (26), (27)) move to their front position (201). Then, the frame on which the support pins (61), (62) are mounted, is lowered by means of the hydraulic cylinders (or other mechanical / electric / hydraulic elements), along an arcuate orbit due to the articulated arms by which it is assembled to the underside of the vehicle and reaches to a point just above the ground. (Figure 7b)

3) The supporting pins (61) / (62) together with their base move forward in respect to the frame, i.e. towards the cargo lifting position. The lifting pins (26) / (27) move downwards until they meet the supporting pins (61) / (62) and each of them“nests” into the respective supporting pin (61) / (62), or takes a position next to it depending on the design option selected. (Figure 7c)

4) The vehicle (12) approaches the cargo (40) and all the pins (26), (27), (61), (62), via appropriate vehicle maneuvers (12) enter into the cargo lifting pockets. (Figure 7d).

5) The frame together (with the supporting pins (61) / (62)) moves slightly down until the supporting pins (61) / (62) touch the ground and support the vehicle (12). The frame together with the pins (61) / (62) is then secured in place, i.e. it is locked in this position, by mechanical or hydraulic, or by any other means. (Figure 7e).

6) The cargo lifting pins (26), (27) are elevated and carry the cargo (40) to a point above the upper part of the vehicle deck. (Figure 7f).

7) The mast (25) moves horizontally on the vehicle to the position (202), carrying and depositing the cargo (40) on the vehicle deck. (Figure 7g).

8) The frame (together with the pins (61) / (62)) are slightly raised upwards, and then the vehicle supporting pins (61) / (62) move together with their base backwards on the frame, i.e. towards the vehicle traveling position. The frame then moves upwards (along an arcuate orbit due to its supporting articulated arms), i.e. moves towards to the vehicle travel position. (Figure 7h).

In order to deposit the cargo on the ground the reverse procedure is followed.

If the cargo (40) to be handled is placed on a deck of any kind, (truck deck, rack of a storage cabinet, etc), the above mentioned procedure is followed, except that when the vehicle (12) approaches the cargo (40), the pins (26), (27) are at the elevation of the cargo lifting pockets (and opposite to them), whereas the pins (61), (62) (together with their base and the frame on which they are mounted on) move downwards to a point a little above the ground and then, a procedure similar to the one mentioned above is followed.

As it can be seen from the above, the cargos which are to be handled by the forklift according to the present invention must be placed on the type of pallets that do not have transverse boards at their bottom. When the cargo is lifted from a deck, then any type of pallet can be used because the supporting pins operate at a lower level (usually on the ground). The above seems to be a disadvantage of the present invention, but it is not really so, for the following reasons:

a) The actual reason that some pallets are provided with transverse boards at their bottom is to increase the bending resistance moment (W) of the pallet along its wide side because this wide side is the one chosen for the lifting process so that during the lifting process the center of gravity of the cargo is as close as possible to the front of the vehicle in order to reduce the overturning moment that is developed by the cargo load. However, according to the present invention, the overturning moment simply does not exist, which means that the cargo can be handled by the narrow side of its pallet, which is usually the one without side boards at the bottom of the pallet.

b) Pallets provided with transverse boards at their bottom may also be used according to the present invention, provided that additional (preferably wooden) blocks, usually of rectangular cross-section, are used. These blocks can either be permanently attached to the bottom of the pallet or simply be placed on the ground and onto them the cargo together with its pallet are placed.

The forklift according to the present invention is ideal for handling large and very heavy cargos.

The forklift according to the present invention is also ideal for special cases of cargos, with its forks being shaped accordingly. For example, in the case of handling a rolled metal coil (which is cylindrical in shape and is stored with its axis in a horizontal direction), there is only one lifting pin (cylindrically shaped) which enters into the central hole of the roll. The supporting pins can operate in any of the above-mentioned options, and due to the cylindrical shape of the coil, they can easily and comfortably take their right and left positions to support the vehicle, thus making it the ideal solution for the handling of the cargo.

The length of the forklift truck can be further reduced and consequently the vehicle (12) can become even more versatile if the vehicle's control cab (31) is removed (eliminated), so that the entire deck of the vehicle body is available for cargo depositing. Operation and driving are carried out by remote control, by an operator who follows the forklift with the remote control in his hands. However, it is preferable for the operator to be sited in a suitably configured seat, located in a control and equipped with all the appropriate controls, steering wheel, etc. Cameras located both on the front and at the rear points of the vehicle carry the image wirelessly on screens which the operator has in front of him, so that he can safely handle the cargo and also safely drive the vehicle. There are also (2 or 4) microphones mounted in appropriate on-board positions that wirelessly transmit stereo or quadruple audio via headphones or even through loudspeakers to the control room so the operator has the complete sense of space that the vehicle is operating or moving. In this way, the panoramic front (but also rear) images are assured when the vehicle is traveling, without limiting the field of view due to the bulky cargos being transported, as it usually happens with the standard forklift trucks.

The versatility of the vehicle may further be increased, in the following way: The wheels of the vehicle (12) operate normally, according to the standard driving requirements of the vehicle (ie they do not have to be capable of rotating 90 degrees around their axis) and the mast (25) together with the cargo lifting pins (26), (27), when they are located on the vehicle body (that is, in position (202) according to Fig. 2), rotate in respect to the vehicle by 90 degrees around a vertical axis, so that the cargo can be handled from the side part of the vehicle. In this way, long cargos have their long side not perpendicular to the direction of movement of the vehicle but parallel to it. This rotation of the mast (25) is possible because the guides on which the vehicle mast (25) is driven are not firmly mounted on the vehicle but they are bridged together and preferably mounted via arcuate linear bearings (sliding or rolling) or via arcuate rails, on a relatively large diameter circular ring, the center of which is located on the axis of rotation of the mast, and which ring is firmly attached to the vehicle.

If the method of the moving frame is used for the supporting pins (Fig. 7), then the frame should also be rotated in a similar manner by 90 degrees, that is to say, the base on which the frame is mounted to is not firmly fixed to of the underside of the vehicle, but it is mounted - preferably via arcuate linear bearings (sliding or rolling) or via arcuate rails - on a relatively large diameter circular ring the center of which is on the axis of rotation of the frame and which ring is firmly attached to the underside of the vehicle. The above mentioned 90 degree rotation of the mast guides on the relatively large diameter ring is realized via a suitable hydraulic, or mechanical, or electromechanical way (that is, either with a hydraulic cylinder, or with a hydraulic or electric motor that drives a gear (conventional or endless) been engaged with an arcuate toothed rule, which is mounted on the relatively large diameter circular ring. The above mentioned are also valid for the rotation of the frame to the underside of the vehicle.

To perform the rotation of both the mast (25) and the frame of the supporting pins by 90 degrees, both the mast guides and the frame supporting structure are joined together via a (appropriately sized) shaft which finds its way through the body of the vehicle and is connected with it through suitable bearings. Additionally, both the mast (25) guides and the frame are mounted on the top and at the bottom of the vehicle respectively, through appropriate bearings. The aforementioned 90 degree rotation of both the mast (25) drivers on the body of the vehicle and the base of the frame to the underside of the vehicle is realized via suitable hydraulic, mechanical or electromechanical means; either by a hydraulic cylinder, or by a hydraulic or electric gear drive motor (conventional or endless type), engaged with an arcuate toothed rule, which is fitted either to the said common axle or to any other suitable point on the guides of the mast or (and) the frame.

If the folding pins method has been selected for the supporting pins (according to Figure 6), the vehicle, in addition to its front fond able supporting pins, is also equipped with another pair of fold able supporting pins located at the side of the vehicle. When the handling of the cargo takes place from the side of the vehicle, the said additional pair of fold able supporting pins is used.

As mentioned above, during the cargo lifting phase, the vehicle mast (25) moves horizontally and transfers the cargo (40) on the vehicle deck. During this process, the weight of the cargo gradually loads the vehicle and its suspensions, resulting in a gradual "lowering" of the vehicle due to the elasticity of the vehicle suspensions. Since the supporting pins remain locked in place, the front part of the vehicle cannot follow the abovementioned "lowering" of the vehicle, resulting to a slight inclination of the vehicle backwards. This problem is addressed by the gradual and controlled relaxation of locking / securing of the supporting pins so that the vehicle and the deck (ie the upper surface of the vehicle) remains constantly horizontal, during the mast (25) movement. The aforementioned gradual and controlled relaxation of locking of the supporting pins is realized according to the locking mode selected for the vehicle. For example, in the case of a hydraulic operation, the oil is drained (with a controlled flow) by the hydraulic locking cylinder (s) of the supporting pins. If it is a rule system and a worm screw, then the screw is rotated by means of the motor (electric, hydraulic etc.) to which it is connected,

Claims

1. Forklift truck (vehicle), the mast (25) of which is capable to move horizontally on the vehicle (12) and carry the cargo on the vehicle deck, while the said vehicle (12) is also equipped with a vehicle supporting device that compensates the overturning moment that is developed during the cargo lifting procedure. Optionally, the vehicle (12) also has wheels, each one of which is capable to rotate up to 90 degrees around its perpendicular axis. In this way, the versatility of the vehicle is increased.

Characterized by that

The weight and the cost of the vehicle are very low and its length is very small, increasing in this way its versatility. These features are achieved due to the characteristics of the vehicle, as described in the claims below. The vehicle (12), apart from its standard cargo lifting fork pins (26), (27) is also equipped with another pair of supporting fork pins (61), (62), for the compensation of the overturning moment developed during the cargo lifting procedure. The cross-section shape of the said supporting pins (61), (62), is not the typical rectangular, but it is an inverted flattened“pi”, with the gap at the top of the cross-section and large enough, so that each cargo lifting pin (26), (27), (whose cross-section is rectangular in shape), may“nest” into the gap of the corresponding supporting pin (61), (62). The supporting pins (61), (62) are mounted on their own base, which is capable to move in the vertical direction, (together with the said pins (61), (62)) along corresponding drivers mounted on the body of the vehicle (12), so that the said pins (61), (62) may reach down to the ground level. This vertical movement of the supporting pins (61), (62) takes place in a way that their vertical portions move along a vertical plane which is behind the plane along which the vertical portions of cargo lifting pins (26), (27) move, so that, enough space is provided for the operation of the cargo lifting ins (26), (27) and the structure (base) that they are mounted on. As it happens with the cargo lifting pins (26), (27), said additional supporting pins (61), (62) can also move horizontally on their base so that each one of them is located (and moving) at the same vertical plane with the corresponding cargo lifting fork (26), (27). The precise alignment of each supporting pin (61) / (62) with the corresponding cargo lifting pin (26) / (27) is achieved via suitable guides. For cargo lifting from the ground, each cargo lifting pin (26) / (27) descends, meets the corresponding supporting pin (61) / (62), and “nests” inside it. Then, via the appropriate maneuvering of the vehicle (12), all four pins together move downwards and enter into the cargo lifting pockets. Then, the supporting pins (61) / (62) move further downwards until they touch to the ground and are“locked” in this position via a mechanical, or hydraulic (or any other) way. Then, the cargo lifting pins (26) / (27), lift the cargo up to a point above the main body of the vehicle, and the mast (25) moves horizontally, carrying and placing the cargo on the vehicle. Finally, the supporting pins (61) / (62) are raised from the ground and elevated to their upper position, so that the vehicle may move and carry the cargo to its destination.

If the cargo(40) to be handled is placed on a deck of any kind, (truck deck, rack of a storage cabinet, etc), the above mentioned procedure is followed, except that when the vehicle (12) approaches the cargo (40), the pins (26), (27 ) are at the elevation of the cargo lifting pockets (and opposite to them), while the supporting pins (61), (62) are slightly above the ground, so they enter below the truck deck, or below the relevant rack of the cabinet in order to touch to the ground (or to lower rack of the cabinet) and support the vehicle.

2. A forklift truck according to claim 1 ,

Characterized by that

The cross sections of the cargo lifting pins (26) / (27) and the supporting pins (61), (62) are shaped in various alternative ways as mentioned below and in every case they“nest” into each other as seen on figure 6c: The cross section of each of the first ones is shaped as a "flattened pi", while the cross section of each one of the second ones is shaped rectangular; or the cross sections of all of them are shaped as "flattened pi" (without necessarily equal width sides) and complement each other without necessarily the centers of gravity of all the cross-sections being on the same vertical line; or all of them are "L" shaped and complement each other; or one is " flattened pi" shaped and the other "m" shaped and complement each other, etc. Furthermore, all four pins (supporting and lifting) may be of rectangular cross section (or any other form) and each cargo lifting pin (26) / (27) may simply be adjacent next to the respective supporting pin (61) / (62) that is, without“nesting” into each other.

3. Forklift truck according to claims 1 or 2,

Characterized by that

The supporting pins (61) / (62), can also be folded on the front of the vehicle, that is, each one of them rotates about a vertical axis (preferably) passing through its vertical portion, and which vertical portion, is mounted on bearings on the base of these pins. During folding, the two pins (61), (62) are preferably not at the same plane, but one of them (61) is further back and lower than the other (62), so that folding is feasible, without the movement of each pin to be affected by the other pin. In addition, the horizontal portion of the rear pin (61) is preferably slightly longer than that of the front pin (62), so that when the pins extend forward, their end points are at equal distance from the front surface of the vehicle. To receive a cargo from the ground or from a deck, the folded supporting pins (61) / (62) descend, extend forward, their horizontal portions come to the same horizontal plane and the procedure to be followed is similar to that mentioned in the claim 1.

4. A forklift truck according to claims 1 , 2

Characterized by that The supporting pins (61) / (62) do not have the familiar "L" shape, but they are straight, horizontally located and their supporting base moves not vertically but horizontally, in a forward-backward direction, while being mounted on a horizontal movable frame which is mounted to the underside of the vehicle. During the vehicle traveling phase, this frame is at its uppermost position, that is, it is either almost in contact with the underside of the vehicle, or“nests” into properly shaped recesses at the underside of the vehicle. In order to support the vehicle during the cargo lifting phase, this frame moves downwards, since it is mounted to the vehicle underside via (four preferably) articulated arms. Said movement is realized via suitable hydraulic cylinders or other mechanical / electrical / hydraulic elements. The supporting pins (61 ) / (62) which together with their base are mounted on the said frame can move horizontally and forward in respect to the frame (i.e. towards the cargo lifting position) and return to their rear position ( ie in the vehicle (12) traveling position), by means of hydraulic cylinders or other mechanical / electrical / hydraulic elements. This (front - rear) movement of the pins (61) / (62) and their base is realized via linear bearings (either sliding or rolling), which are located on the said frame.

To receive a cargo (40) from the ground, the vehicle (12) approaches the cargo (40) and the mast (25) together with the lifting pins (26), (27) takes its front position (201), while the frame on which the supporting pins (61) (62) are mounted, moves downwards along an arcuate orbit, due to the articulated arms through which it is mounted to the vehicle (12), until it reaches to a level just above the ground. Then, the supporting pins (61) / (62) together with their base move forward in respect to the frame, that is, to the cargo lifting position and the lifting pins (26), (27) move downwards, until they meet the supporting pins (61) / (62) and“nest” into them respectively, (or according to the alternative design, they take place next to each other). The vehicle (12) approaches the cargo (40) and all pins (26), (27), (61), (62), through the appropriate maneuvers of the vehicle (12), enter into the cargo lifting pockets. The frame together with the supporting pins (61) / (62) move slightly further downwards until the supporting pins (61) / (62) touch the ground and the frame is locked in this position, by mechanical, or hydraulic, or any other means. Then the cargo lifting pins (26), (27) move upwards and carry the cargo (40) to a point above the deck of the vehicle (12). Then the mast (25) moves horizontally on the vehicle to the position (202), carrying the cargo (40) on the vehicle (12). Thereafter, the frame with the supporting pins (61) / (62) of the vehicle is slightly raised until the pins (61) / (62) cease to rest on the ground, so that the pins (61) / (62) together with their base, move backwards in respect to the frame, and after this, the frame (together with the pins (61) / (62) and their base) moves upwards along an arcuate orbit, and reaches its upper position, meaning the vehicle (12) travelling position. The reverse procedure shall be followed for the deposition of the cargo on the ground. If the cargo (40) is on the deck of any type, the above procedure is followed, except that when the vehicle (12) approaches the cargo (40), the pins (26), (27 ) are at the elevation of the cargo lifting pockets, (and opposite to them), while the frame together with the supporting pins (61), (62) and their base descend slightly above the ground and then the pins ( 61), (62) together with their base move forward in respect to the frame. The frame (together with the supporting pins and their base) is lowered slightly until the pins (61), (62) touch the ground. Alternatively, the frame (on which the supporting pins (61), (2) are mounted) moves downwards or upwards along a straight line (and not along an arcuate orbit), via suitable guides / rails which are located on the vehicle (12). Said movement is realized via suitable hydraulic cylinders or other mechanical / electrical / hydraulic elements.

5. Forklift truck according to claims 1 , 2, 3, 4

Characterized by that

Targeting to its further size reduction, the vehicle (12) does not have a control cabin, so the upper side of the vehicle body is entirely available for the cargo (40) storage. The operation and driving of the vehicle are carried out remotely by an operator who follows the forklift with the remote control in his hands.

6. Forklift truck according to claims 1 , 2, 3, 4

Characterized by that

Targeting to its further size reduction, the vehicle (12) does not have a control cabin, so the upper side of the vehicle body is entirely available for the cargo (40) storage. The vehicle is operated by an operator sitting in a well-positioned control room, equipped with all the appropriate controls, steering wheel, etc. Cameras mounted on both the front and the rear sides of the vehicle wirelessly transfer the image to front-facing screens in the said control room. In this way, the operator can handle the vehicle comfortably and drive it safely. There are also (2 or 4) microphones mounted in appropriate positions on the vehicle that wirelessly transmit stereo or four-way audio via loudspeakers to the control room so that the operator has a complete sense of the place where the vehicle is operating or moving.

7. Forklift truck according to claims 1 , 2. 3, 4, 5, 6

Characterized by that

It has a single cargo-lifting / transferring pin which is (preferably) cylindrical in share, which enters into the central opening of a rolled metal coil, (which is cylindrical in shape and is stored with its axis positioned horizontally). The two supporting pins take their place to the right and to left of the coil respectively, following one of the procedures mentioned in claims 1 , or 2 or 3 or 4.

8. Forklift truck according to claims 1 , 2, 4, 5, 6

Characterized by that The wheels of the vehicle (12) operate normally, according to the standard driving requirements of the vehicle (ie they do not have to be capable of rotating 90 degrees around their axis) and the mast (25) together with the cargo lifting pins (26), (27), when they are located on the vehicle body (that is, in position (202) according to Fig. 2), rotate in respect to the vehicle by 90 degrees around a vertical axis, so that the cargo can be handled from the side part of the vehicle. In this way, long cargos have their long side not perpendicular to the direction of movement of the vehicle but parallel to it. This rotation of the mast (25) is possible because the guides (on which the vehicle mast (25) is driven) are not firmly mounted on the vehicle but they are bridged together and preferably mounted via arcuate linear bearings (sliding or rolling) or via arcuate rails, on a relatively large diameter circular ring, the center of which is located on the axis of rotation of the mast, and which ring is firmly attached to the vehicle. If the method of the moving frame is used for the supporting pins (Fig. 7), then the frame should also be rotated in a similar manner by 90 degrees, that is to say, the base on which the frame is mounted to is not firmly fixed to of the underside of the vehicle, but it is mounted - preferably via arcuate linear bearings (sliding or rolling) or via arcuate rails - on a relatively large diameter circular ring whose center is on the axis of rotation of the frame and which ring is firmly attached to the underside of the vehicle. The above mentioned 90 degree rotation of the mast guides on the relatively large diameter ring is realized via a suitable hydraulic, or mechanical, or electromechanical way, that is, either with a hydraulic cylinder, or with a hydraulic or electric motor that drives a gear (conventional or endless), been engaged with an arcuate toothed rule, which is mounted on the relatively large diameter circular ring. The above mentioned are also valid for the rotation of the frame to the underside of the vehicle.

9. Forklift truck according to claims 1 , 2, 4, 5, 8

Characterized by that

To perform the rotation of both the mast (25) and the frame of the supporting pins by 90 degrees, as mentioned in claim No 8, both the mast guides and the frame supporting structure are joined together via a (appropriately sized) shaft which finds its way through the body of the vehicle and is connected with it through suitable bearings. Additionally, both the mast (25) guides and the frame are mounted on the top and bottom of the vehicle respectively, through appropriate bearings. The aforementioned 90 degree rotation of both the mast (25) drivers on the body of the vehicle and the base of the frame to the underside of the vehicle are realized via suitable hydraulic, mechanical or electromechanical means; either by a hydraulic cylinder, or by a hydraulic or electric gear drive motor (conventional or endless type), engaged with an arcuate toothed rule, which is fitted either to the said common axle or to any other suitable point on the guides of the mast or (and) the frame.

10. A forklift truck according to claims 1 , 2, 3, 5, 6, 8

Characterized by that

Regarding the supporting pins, instead of the method seen on Fig. 7, the folding pins method is used (seen on Figures 3 and 6). The vehicle, in addition to the front fond able supporting pins, is also equipped with another pair of fold able supporting pins located at the side of the vehicle. When the handling of the cargo takes place from the side of the vehicle, the said additional pair of side fold able supporting pins is used.