GRIP AND BLOCK SYSTEM FOR A FORKLIFT TRUCK AND RELATED FORKLIFT TRUCK

DESCRIPTION

The present invention concerns an improved cargo box grip and block arrangement for trucks of a type provided with forklif t means, an improved cargo box grip and block system and a forklift truck provided with such an arrangement and/or system. In the present document as to cargo box grip and block arrangement and system has to be intended a cargo box grip and block arrangement and system adapted to be operated by a forklift truck.

Main application field of this invention is agricultural machinery. In this field, lift trucks provided with forklift means, being more easily called forklift trucks, are typically used for loading and unloading cargo boxes containing agricultural products, where cargo boxes are overturned to drop down produtcts in further cargo boxes or contaniners . The invention can be applied to other fileds of technique, i.e. all those fields employing large sized cargo boxes containing goods and products with the same need of operation and overturning, which can be operated through forklift trucks.

More in detail, in an embodiment, the invention concerns a grip and block arrangement of a cargo box to be operated, in particular operating above a cargo box, being associated to grip and block means apt to set out a cargo box blockage by gripping and grabbing the cargo box. In a further embodiment, the invention concerns a cargo box grip and block system of a type comprising grip and block means apt to carry out cargo box blockage by grabbing a cargo box from both above and below, said means not comprising any forks.

In the field of agricultural machinery cargo boxes, named as "bins", being made of various materials to contain agricultural products, as plastic, iron and woods, are become more and more utilized and functional. Such cargo boxes are very spacious and, overall, easily movable by means of forklift trucks, which are needed of related grip and block means apt to block the cargo box in order to operate, overturn and empty it. Such trucks, by forking from the botom of the cargo box through related means, are easily able to operate and load it, for example on a truck, for a subsequent moving to a destination.

hi the prior art we can look up grip and block cargo box arrangement and system for forklift trucks using, for actuation thereof, the same forklift truck hydraulic circuit which leads, over said grip and block cargo box arrangement and system, an arrangement for vertically moving the forks in order to raise the cargo box and the related grip and blockage thereof, an overturning device apt to overturn the cargo box and to empty the related contents in a provided container, typically a box of a truck, a trailer thereof or a machinery hopper.

It's a long felt need, in the field, to firmly, steadly and safely grip and grasp a cargo box in order to operate a cargo box displacement and overturning. At the same time, during grip and blockage, a cargo box must be balanced and steady with respect to ties as set out by grip and block means of the cargo box grip and block system, so that the weight of agricultural products contained therein does not contribute to damage and, at the limit, to crash the same cargo box while operating, with risk of loss of load during operation and a consequently loss of time for recovering the lost load.

Furthermore, known arrangements and systems force an operator driving a forklift truck to be very precise during the operation of approaching the cargo box through truck forks in order to efficaciously carry out the cargo box grip and blockage by grabbing the cargo box from the bottom and the top. If an operator is not completely focused on that specific operation so that the elevation part of the forks does not come to touch or comes to be particularly closed to the cargo box, it is probable that the further operation of cargo box grip and blockage will be uneffective, because the upper part of the grip and block arrangement of the cargo box grip and block system does not come to intercept the cargo box upper edge to block it, or intercepts it with a part thereof inducing bending load on the cargo box lateral wall, deforming it. In such a case, the cargo box forcking operation has to be improved or repeated, with useless loss of time.

In the prior art grip and block arrangement acting above a cargo box to be operated are known, which are provided with a pressure louver shaped in a sole piece and made of a pressure level being substantially horizontal in a grip and blockage operative condition, apt to exert a pressure on a cargo box upper edge, the pressure level thereof tending with an inclined plane to drive a possible cargo box upper edge toward the pressure level when pressed down. In case the cargo box is very heavy and an operator does not come to properly fork the cargo box, i.e. the cargo box edge is next to the pressure louver inclined plane, once it is commanded and actuated the grip and block system the pressure louver comes to push down, by the inclined plane therof, the cargo box upper edge so inducing a great bending stress on the cargo box walls. Such a tensional state, during the cargo box operation, puts on seriously risk to damage and/or crash it. Known cargo box grip and block systems employ, during cargo box grip and block operations being typically actuated by a so called "triple action" hydraulic piston arrangement commanding a cargo box grip and moving operation, inferior louvers apt to be located below the cargo box and acting in opposition to a top-down pushing upper pressure louver in order to block the cargo box with a proper pressure in an way completely indipendent from any forks operation. Such inferior louvers, sometimes shaped as short hook, sometimes tend to generate relevant local stresses inside cargo boxes structures, which can be damaged with their long time operation, so requiring a more frequent cargo boxes replacement, sometimes risking failures and crashing during their moving.

The present invention aims to solve the above mentioned prior art drawbacks and to indicate a grip and block arrangement for truck of a type provided with forklift means, a grip and block system for forklift truck and a related forklift truck assuring a superior reliability and efficiency to the forklift trucks during any cargo box moving and overturning operations.

A purpose of the present invention is that of reducing any risk of damaging a cargo box during the operation of gripping, moving and overturning it.

Another purpose is that of being able to employ, for trucks moving, operators not so much experienced and, at the same time, assuring safe and affective operations.

Another purpose is that of carrying out a cargo box grip and block arrangement and system of a substantially simple and largely reliable workmanship as of their operation.

To achieve these purposes, the object of the present invention is a cargo box grip and block arrangement for forklift truck, a cargo box grip and block system for forklift truck and a respective forklift truck comprising said cargo box grip and block system according to the features of the enclosed claims.

In an embodiment, the invention concerns a cargo box grip and block arrangement of a type comprising:

- a main body providing a bearing part, in particular substantially vertical developed, associated to grip and block actuating means of a forklift truck grip and block system apt to carry out a cargo box blockage by grabbing it,

- a pressure level associated to the main body and apt to exert, in a blockage operative condition of said grip and block actuating means, a pressure on part of a cargo box upper edge,

- grip automatic actuating means operating on part of a lateral surface next to a cargo box upper edge when the upper edge comes to be closed to the bearing part, said grip automatic actuating means being associated to the main body to implement the gripping blockage on the upper edge and to avoid a cargo box longitudinal shift.

In an embodiment thereof, grip automatic actuating means can advantageously comprise intercepting and block rotating means associated to the main body to rotate a shaped element being located in such a way to be intercepted from the cargo box upper edge when the upper edge comes to be closed to the bearing part of said arrangement, the rotation setting out a barrage to the cargo box longitudinal shift and a related grip on the box with the arrangement passing, clearly in an automatic way, from an unblock to a blockage operative condition. In such an embodiment, the grip and block arrangement implements in a simple and automatic way a cargo box blockage at the possible longitudinal shift, the used means being completely automatic operated and therefore being operatively highly reliable.

In an embodiment, the present invention concerns cargo box grip and block system as per the preamble of claim 1. Peculiarity of the grip and block system is that of comprising a forged foot, rigidly associated to the piston means second end, which comprises a forged plate being longitudinally cantilevered located with respect to the second end and adapted to distribute, when the system is in a blockage operative condition, the pressure on part of an outer inferior surface next to a cargo box inferior edge. More in detail, the forged plate has longitudinal symmetry and provides a central portion from which a couple of islands develops lateral to a longitudinal symmetry axis for an optimal stress distribution on a cargo box inferior surface.

Advantageously, the forged plate provides a cantilever longitudinal dimension greater of

0,1 times the forklift truck forks longitudinal extension and a width greater of 0,2 times the breadth inbetween the fork couple as typically used for a defined cargo box to be operated. The applicant has studied and noticed that quite using the specifications as above cited concerning the forged plate, inner stress inside the structure results more evenly distrubuted, with stress peaks less high when it is full load operated, so removing any risk to damage and/or crash the cargo box structure. This is particularly valid when a pressure strenght is evenly applied on the cargo box both top-down through the cargo box grip and block arrangement, and from the bottom up to the top by the forged plate, i.e. when controlled shifting means of a piston means end located inbetween the second end thereof and the bearing frame are further present.

The cargo box grip and block system according to the invention, because the cargo box grip and block arrangement automatically runs in a blockage position when a forklift truck operator forcks a cargo box, requires less precision during a forcking operation and therefore less accuracy W

5

for the operator running the truck with respect to prior art forklift trucks, so speeding cargo box moving operations, at the same time the operator resulting less stressed.

An advantage is that of setting out a cargo box grip and block arrangement and system of easy implementaion and assembly, as well as cheap to be produced and of reduced maintenance.

An advantage is that of assuring the biggest steadiness and a uniform distribution of stress inside a cargo box structure to be operated by trucks, with a low risk to damage or crash a cargo box when they are full loaded.

Further objects, features and advantages of the present invention will be evident with the following detailed description of a preferred embodiment and related variations thereof, which are provided just as an explanatory and non restrictive examples, with the contribute of the enclosed figures, therein:

- figures 1 and 2 illustrate a perspective view, rispectively in an assembled and exploded condition, of a grip and block arrangement according to the invention, in particular in an unblock position of the arrangement;

- figures 3 and 4 illustrate a perspective view of a grip and block system according to the invention lacking of a cargo box to be operated, rispectively in unblock and blockage operative condition;

- figures 5 and 6 illustrate perspective views of the grip and block system according to the invention including the cargo box to be operated, in the operative conditions of rispectively figures 3 and 4;

- figure 7 depicts a plan view from below of the system of figure 6;

- figure 8 illustrates a plan view from below of a relevant detail of the system according to the invention;

- figures 9 and 10 represent perspective views, in two different operative conditions, of a forklift truck according to the invention.

With reference to above cited figures and in particular to figures 1-6, with 10 is indicated as a whole a grip and block arrangement of a cargo box C to be operated, in particular operating at the top of the cargo box C, for forklift truck FT, which comprises:

- a main body 11 providing a bearing part llv thereof, in particular substantially vertical developed and rotated C-shaped, associated to grip and block actuating means of a forklift truck

FT grip and block system 20 apt to carry out a cargo box C blockage by grabbing the cargo box C,

- a pressure level 12 associated to the main body 11, in particular at the bottom of the bearing part 11 v thereof, apt to exert, in a blockage operative condition of said grip and block actuating means, a pressure on part of a cargo box C upper edge 50.

Forklif t truck FT grip and block system 20 is associated to an overturning arrangement apt to rotate the same system for overturning a cargo box C to be operated, which is not further detailed together with other elements of the same system 20 because they are known. Such system 20 comprises a bearing frame 22 apt to be associated to said overturning arrangement for a cargo box C overturning, a cargo box C grip and block arrangement 10 associated to the frame 22 and grip and block actuating means being composed of:

- driving means associated to the bearing frame 22 for a substantially vertical displacement of a respective driving element, for example an upper traverse 23, apt to be rigidly associated to the arrangement 10 main body 11, in particular to the extremal upper part of the bearing part 11 v thereof, the driving means being, for example, composed of a telescopic slide 24 on the top thereof, the upper traverse 23 being rigidly connected,

- pulling and pushing piston means 30 being associated, by a first end 31 thereof to the upper traverse 23, by a second end 32 thereof to the bearing frame 22, through interposition of controlled shifting means of an end 32 of said piston means 30 with respect to the bearing frame 22,

- leading and actuating means, herein not represented and detailed because they are known, being associated to a forklift truck FT control and leading centre, apt to lead a piston means 30 elongation and/or shortening from an unblock operative position (figures 3 and 5) to a blockage operative position and vice-versa of the grip and block system 20.

More in detail and with particular reference to figure 3, said pulling and pushing piston means are composed, for example, of a hydraulically driven pulling and pushing piston 30 led by a forklift truck FT guide and control system of a known type; said controlled shifting means of a piston means 30 end 32 with respect to the bearing frame 22 are composed, for example, of a couple of substantially vertical developed slots 25, laterally machined on a front boss of the frame 22, inside that a pin 34 connected to the piston 30 second end 32 is inserted for a relative shifting in a driven direction following a defined path, in particular substantially vertical developing inside the slots 25.

Grip and block arrangement 10 comprises grip automatic actuating means, in particular esclusively mechanical operated, acting on part of the cargo box C lateral surface, in particular on the inner surface 52 thereof next to the upper edge 50 when it comes close to the same bearing part llv, said automatic means being associated to the main body 11 to assure grip and blockage of the upper edge 50 and so avoiding a cargo box C longitudinal shifting.

Grip automatic actuating means comprise intercepting and block rotating means associated to the main body 11 to rotate a shaped element 15 being located in such a way to be intercepted from the cargo box C upper edge 50 when the upper edge 50 comes to be close to the arrangement 10 bearing part llv, the rotation setting out a barrage to the cargo box C longitudinal shift and a related grip on the cargo box C while the arrangement 10 moves from an unblock operative condition (as in figures 3, 5) to a blockage one (as in figure 6). More in detail, said intercepting and block rotating means are composed, for example, of:

shaped element 15, in particular L-shaped, which is hinged to the main body 11 at the intersection of a respective intercepting flat section 16, which in an unblock operative condition of the arrangement 10 lies in a substantially vertical position apt to work as a barrage for the cargo box C upper edge 50 while moving forward to the bearing part llv, a barrage section 17 resting in a substantially horizontal position;

hinge means associated to the main body 11 and to an intersection of the shaped element 15 respective sections 16, 17 for the rotation thereof with respect to the main body 11, being for example composed of a pivot 18 passing inside circular holes 19 machined inside angle bars of the shaped element 15 and apt to engage inside circular shaped receptacles provided inside the main body 11, in particular an horizontal llh thereof, for the related rotaion of the element 15 with respect to the main body 11,

resilient means associated to said hinge means and shaped element 15 being apt to usually move the intercepting flat section 16 in a substantially vertical position when the arrangement 10 is in an unblock position, for example torsion springs 14 inserted between the pivot 18 and the horizontal part llh of the main body 11 and set out to usually mantain the section 16 in a substantially vertical position.

Grip and block arrangement 10 moves from an unblock position of figures 3 and 5 to a blockage one of figure 6 as soon as the cargo box C upper edge 50 comes to be close to the main body 11 bearing part llv, so getting in touch and pushing forward the shaped element 15 intercepting flat section 16, which rotates together with the barrage section 17 moving in vertical position while the arrangement 10 moves into a blockage operative position, so avoiding any possible cargo box C longitudinal shifting. At the same time, such intercepting flat section 16 moves horizontally and is shaped in such a way to set out, by means of its surface and part of a main body 11 horizontal part llh lateral sections inferior surface, a one sole pressure surface advantageously forming a wide and coplanar pressure level 12 for a more balanced and therefore effective grab on the cargo box C upper edge 50.

Grip and block system 20 comprises a forged foot, indicated as a whole with 40, which is rigidly associated in a easily removable way to the piston means 30 second end 32 for operating by pushing on part of a cargo box C inferior outer surface 53.

Such forged foot 40 comprises, rigidly and in a easily removable way cantilevered to an inferior part of the second end 32, for example by bolting, a forged plate 42 apt to advantageously distribute, when the system 20 is in a blockage operative condition, the pressure on a wide part of the outer inferior surface 53 next to a cargo box C inferior edge 54, as in particular shown in figure 7. More in detail and with reference to figure 8, the forged plate 42 has a longitudinal symmetry and provides a central portion 43 from which a couple of islands 44 develop, in particular substantially rectangular in plant shaped, lateral to a longitudinal symmetry axis thereof for an optimal load distribution on the cargo box C inferior surface 53.

Said forged plate 42 provides a cantilever longitudinal dimension 1 greater of 0,1 times the forklift truck FT forks F longitudinal extension L and a width W greater of 0,2 times the breadth P in-between the forks F couple as typically used for operating a defined type of cargo box C. The applicant has studied that by using such measurements proportions, the cargo box C structure inner stress results advantageously much better distributed with respect to the one of a known solution providing an inferior louvers grabbing on a cargo box inferior edge, so avoiding dangerous stress peaks on the inferior surface 53 next to the piston 30 second end 32 and advantageously removing any danger of cargo box structure deformation and possible crash when it is stressed by heavy loads during an overturning operation thereof.

In order to improve the foot 40 grip and to distribute in a more balanced way any stress on the cargo box C, above a grip surface of the forged plate 42, for example a couple of islands 44, a grip gasket 46 is applied, in particular providing a plant substantially corresponding to a forged plate 42 grip surface, for example substantially corresponding with a rectangular in plant shape of each of the island 44.

Such grip gasket 46 has advantageously a shape apt to evenly distribute on the cargo box C inferior surface 53 a gripping force as set out by the grip and block system 20 in a blockage operative condition thereof; hence its shape modifies according to each specific type of utilized cargo box C. For example, a grip gasket shape could be of a greater extension in lenght as well as in widht and/or rounded with respect to islands shape, or of a particular shape as the cargo box would provide housings specifically designed and fitted to grasp the same gaskets inside them.

Herein, a cargo box grip and block system and arrangement operation according to the invention is described as follows, in particular when an operator of a forklift truck FT comes close to a cargo box C with a couple of turck FT forks F, activates an hydraulic command running on such system and arrangement until reaching a blockage operative position.

As soon as the forklift truck FT come forward to the cargo box C moving the main body 11 bearing part llv next to the upper edge 50 thereof, the arrangement 10, as previously described, automatically moves in a blockage operative position with the barrage section 17 in a vertical position, so preventing a possible cargo box C longitudinal shifting. An operator can now activates a forklift system, the forks F thereof getting in touch with part of the cargo box C inferior surface 53 and then lifting the same. At this time the cargo box C grip and block system 20 is activated in a blockage position by means of a control system leading a piston means 30 shortening, which pulls together with it:

a) on the top the cargo box grip and block arrangement 10, which moves the pressure level

12 thereof first to get in touch with the cargo box C upper edge 52, then to carry out on it a grasp pressure downward,

b) on the bottom the forged foot 40, moving the forged plate 42 thereof together with the related gaskets 46 first to get in touch with and then to push up that part of the cargo box C inferior surface 53 next to the inferior edge 54, form the bottom to the top.

Now it is possible moving and overturning a cargo box C in total safe, also when fully loaded, in particular through a gripping force acting in a substantially vertical direction with respect to cargo box elevation.

Advantageously, the mutual action of a vertical translation both downward of the cargo box C block and grip arrangement 10 and upward of the forged plate 42 attached to the second end 32 by means of the controlled shifting means 25 when the piston means 30 shorten, as well as the specific design of the same forged plate as above detailed, bring about generating less stress into the cargo box C structure in case of the same pressure being actuated by the system 20 on the cargo box C. This evidence is confirmed by studies and trials as experienced by the applicant.

Once a truck operation ends, as soon as an operator is willed to let the cargo box rests on its feet, leads the system 20 in an unblock operative condition: piston means 30 lenghten and move the driving means 24 so distancing rispectively the arrangement 10 and the forged plate 42 from the contact with the related part of the cargo box C, which now is not any more blocked and rests on the forks F.

Advantageously, such cargo box block and grip system is provided with an arrangement for adjusting the breadth P in-between the forks F, for example of a step-by-step breadth P adjusting type and composed, for example, of a segmented bar 26 attached to the frame 22 and provided with adjusting notches 27 wherein a couple of forks carriages 28 are attached, inside those a couple of forks F are inserted, typically the same genuine forks of the forklift truck FT.

In a variation thereof, a breadth in-between the forks adjusting arrangement could be of a breadth continous adjusting type, that is provided with hydraulic devices apt to allow a continous shifting of a couple of forks carriages to increase or decrease the breadth in-between the forks. Advantageously, the system as so featured results of a particularly flexible use, by adapting itself to operate cargo boxes of a more various dimensions and constitutions.

Aimed to assure a great flexibility to the system according to the invention, the system 20 is provided with a forged foot 40 having a forged plate 42 of an extractable and replaceable type. So it is possible simply substituting the forged plate with another of a different shape and/or dimensions according to a cargo box type and/or dimensions and/or load type to be operated in order to minimize any stress inside a cargo box structure, for example through interposition of an automatic release mechanical arrangement or where the forged plate is simply bolted on the piston second end bottom.

Forks operation results indipendent from the cargo box grip and block system, which brings advantageously about a possibility of using the truck in an autonomous way from the same system; as well as it is possible to furnish the truck with customized elements of the cargo box grip and block system, as for example different types of forged feet.

It is clear that different variations and embodiments are possible for the technician skilled in the art to the cargo box grip and block arrangement and system for forklift truck and to the forklift truck provided with said arrangement and system according to the present invention; as well as it is clear that, in their practical implementation, the forms of the illustrated details may be different and be replaced with other technically equivalent elements.

For example, the main body shaped element of the cargo box grip and block arrangement may be provided with a different embodiment to carry out a mechanical and exclusively mechanical operation so that the intercepting flat section moves in a substantially vertical position when it is not intercepted from a cargo box upper edge. For example, the intercepting flat section can be provided with an addball mass on the part thereof extremal to the rotation, so allowing natural rotation thereof in a vertical position without any need of resilient means.