EP1007410B1

EP1007410B1 - Improved apparatus for automatically filling containers with individual products, in particular vegetables and the like

Info

Publication number: EP1007410B1
Application number: EP98904038A
Authority: EP
Inventors: Angelo Benedetti
Original assignee: UNITEC Srl
Current assignee: UNITEC Srl
Priority date: 1997-01-23
Filing date: 1998-01-07
Publication date: 2002-04-03
Anticipated expiration: 2018-01-07
Also published as: DE69804633D1; IT1294113B1; ES2175662T3; EP1007410A1; ATE215467T1; ITPN970005A1; WO1998032659A1

Abstract

Automatic apparatus for filling containers (3) with individual products, comprising at least a sliding conveyor (2) to transfer said products from an initial station to a final station, at the unloading end of which there is provided a hopper (4); means to operate the conveyor with a reciprocating movement parallelly to the product conveying direction thereof; at least an oscillating support structure (5) for a container, said structure being actuatable on the outlet side of said hopper (4) to move from an initial raised position to successive decreasingly angled positions. The conveyor is capable of accomplishing a forward displacement into the container and a backward displacement during which the products are unloaded in successive layers in the container. As each single layer of products is laid down in the container, the conformation of the layer immediately below is identified and the layer thereon is laid down in such a manner as to compensate for the irregularities in the distribution of the layer therebelow.

Description

The present invention refers to an improved apparatus for automatically filling containers and/or boxes and/or crates, generally referred to as "bins" in the art, with loose products, in particular vegetables or fruit.

Complex apparatuses for automatically filling containers with individual or loose solid products are known in the art, which make use of particular architectures and operating methods depending on the type of automatic sorting technique employed.

One of such apparatuses is described in the European patent application EP 0 641 716 to T.N.T. KNOWW HOW APPLICATIONS AND TRADING S.r.l., which teaches a substantial innovation in the method of loading such containers, consisting basically in the fact that said container is loaded in successive layers with loose products through an appropriately synchronized and programmed combination of movements by the loading devices involved in the process, wherein a first movement is given by the forward and backward motion of the unloading mouth which is fed with products coming from a conveyor belt andmoves sequentially into backward and forward positions with respect to the length of the container (said length direction being taken along the axis of said first movement), and a second movement is given by the rotation of the container about a horizontal axis so as to keep the unloading mouth constantly within the volume of the container.

In the current practice, however, it has been observed that such a solution, while fully feasible and effective, has some drawbacks in conncetion with the loading and levelling of the loose products that can be described as follows:

a) since the loose products are loaded with an irregular sequence and from an unloading mouth that is substantially as large as the container itself, it may occur that such products arrange themselves in the container in an irregular manner; in particular, they may also arrive from the feeder and be unloaded at such a temporarily fast rate as to tend to pile up immediately under the unloading mouth before the latter has actually had any possibility of moving backward to make use of new free space therebelow; loading zones are thereby created in which the products are placed down in an irregular manner, or "heaped up", resulting in an irregular, incomplete filling of the container;

b) such a drawback is further aggravated when the last layers of products are being laid down during the final phases of the loading process, so that it may well occur that the height of said heaps of products extends beyond the upper or loading aperture of the container, whereby a drawback is added in that the products extending beyond such an aperture tend to hinder the subsequent phases in which the loaded bins are stacked, whereby said products are damaged;

c) a third drawback derives from the circumstance that, since the products may arrange themselves in a rather irregular and unpredictable manner under the unloading mouth as a generic reference layer is being laid down, when the next layer of products is then laid down over said reference layer the lower portion or edge of the unloading mouth may intercept and press against the products tnerebelow which possibly protrude with respect to the level programmed for the previous reference layer, whereby such products would be more or less seriously damaged, in particular when the products handled are vegetables and fruit which are particularly sensitive to any kind of contact and/or pressure being exerted on their surface.

From EP 0 464 944, an apparatus for uniformly filling a container with products such as fruits or the like is known.

In said apparatus the position of the container is changed during filling, depending on the instantaneous weight or level of the filling in the container.

Such result is obtained in that a tongue, able to move back and forth in an horizontal direction is provided below a product supply, said tongue assuming such a position, depending on the instantaneous weight of the filling that the height of the drop of the products is kept at a minimum at all times and the container is filled uniformly.

However said solution is only able to solve the problem explained in the above point c) where the drawbacks showed in the above points a) and b) have been fully ignored.

Furthermore, according to EP 0 464 944, the instantaneous weight of the container is at all times considered in order to move said tongue in the correct position; but this fact that the position of said tongue is kept dependent on the weight of the container cannot always eliminate the problem of possible incorrect loading that can harm the products.

It therefore is a main purpose of the present invention, which therefore qualifies as an improvement to the above cited European patent application, to provide some technical solutions which, when applied to apparatuses for automatically filling containers with loose products of the afore mentioned kind, are capable of eliminating the above described drawbacks.

Such solutions shall furthermore be reached through the use of techniques, materials and component parts that are simple and readily available on the market, and the implementation of an apparatus that is able to bring about a sure improvement and an appreciable increase in the uniformity with which the containers are actually filled, without any significant increase in costs and any setback in overall reliability.

According to the present invention these aims are reached in an automatic filling apparatus that comprises:

at least a product feeding device, or feeder, that is guided in a substantially horizontal manner and is adapted to transfer said products from an initial or loading station to a final or unloading station, said device comprising means for unloading, preferably by gravity, said products into said containers;
means to drive said feeding device with a reciprocating motion in the direction of feeding of such products;
at least a support structure for a container, adapted to oscillate in an articulated and actuatable manner at the outlet side of said feeding device;
means to actuate said support structure from an initial raised position, in which said container is raised so that its filling aperture is oriented toward said feeding device at a pre-selected maximum angle, to subsequent working positions in which said container assumes progressively decreasing angles, said feeding device in said working positions being capable of carrying out, jointly with said unloading means, a forward movement within said container and a backward movement during which the products are substantially unloaded in successive layers into the container, and being further provided with automatic means adapted to identify, as a generic layer of products is being laid down in the container in the afore described manner, the projection, on a vertical plane parallel to the axis of the forward and backward movement of said feeding device, of the profile of the products laid down in the previous layer , and to therefore arrange said generic layer being laid down in such a manner as to enable any possible irregularity in the surface distribution of the previous layer to be at least partially compensated for, while preventing any such product from falling down or rolling off.

The invention will be more readily and clearly understood in its characteristics and advantages from the description that is given below by way of non-limiting example with reference to the accompanying drawings, in which

Figures 1 and 1a are a schematical, perspective view of an apparatus according to the present invention, without and with the associated bin, respectively;
Figure 2 is an enlarged view of a central portion of the drawing appearing in Figure 1;
Figure 3 is a view of the apparatus shown in Figure 2, however in a different working position;
Figure 4 is a symbolically illustrated, enlarged view of a detail of Figure 1A;
Figures 5 through to 12 are schematical side views of an apparatus according to the present invention, illustrated in corresponding working positions;
Figure 13 is a symbolically illustrated view of the architecture of the positioning and motion control of a detection device in an apparatus according to the present invention.

With reference to the above listed Figures, an apparatus according to the present invention can be noticed to comprise, further to a load-bearing frame or structure 1, following main sub-assemblies along with a number of further component parts and devices which are needed in view of ensuring the due operation thereof, but, owing to them not being strictly relevant to the actual scope of the present invention, shall anyway not be dealt with here for reasons of greater simplicity:

a motor-driven feeding conveyor which is provided with two motor drive systems, ie. a motor drive system for the translatory motion of the whole conveyor forward and backward within and from the container and a motor drive system for the sliding motion of the same conveyor.
In other words, said conveyor picks up the fruit from an initial station (not shown) and conveys it into the bin or container 3, an unloading hopper 4, which will be described in greater detail further on, being associated to the end portion of said conveyor;
a seat or base 5 for inclining the container 3 from a horizontal position to a fully vertical position of a motor-driven catenary 6 for loading an empty container and unloading a full container, such a catenary being capable of operating only when it is in its horizontal position;
two encoders (not shown), of which one is to detect the degree of inclination of the container placed on said base, while the other one is to detect the position in which the conveyor 2 is situated when it carries out horizontal translation motion;
a central control unit (not shown), in the memory of which there is stored a pre-set programme of container filling cycles, wherein said programme considers just two variables, ie.:
1) the inclination of the container through the base 5, and
2) the horizontal translation of the conveyor 2.

According to the inclination of the container (through said base), the conveyor and the therewith associated hopper will undergo an either longer or shorter translatory motion depending on the programme that is carried through by said central control unit.

The cycles of forward translation of the conveyor to start unloading, and backward translation of the same conveyor to unload the fruit by laying it down into the container, are in turn always programmed according to the inclination of the same container.

A core point of the present invention essentially consists in setting up and completing the whole apparatus with a plurality of sensors of various types, preferably photoelectric cells and feeler-like or similar probes, arranged in various positions both above the surface of and inside the container, so as to enable the upper layer of products to be detected at various points and the related information is sent to said central control unit for it to control the aforw cited motor drives accordingly. Said sensors are:

a feeler-like probe 10 arranged under the collecting and unloading hopper and formed essentially by at least two sensors for the operation thereof, preferably two sensors for each side for a total therefore of four sensors. These sensors have the task of detecting the position of the layer 32 of fruit pieces inside the container relative to the hopper 4 itself and the conveyor 2.

During operation, the probe detects the level reached by the fruit inside the container since that, being it positioned under the head portion of the horizontally forward and backward translating conveyor, it is able to feel the level of the underlying layer of fruit thanks to the fact that, when the conveyor carries out its translatory movements, it oscillatingly carries along said probes 10 with it, so that such probes come under certain circumstances to interfere with the layer of fruit.

Therefore, when the probe detects the fruit, this means that the fruit itself is situated at a pre-defined and known distance from the head portion of the conveyor; the corresponding signal that is in this way delivered by the probe is such as to enable the inclination of the container to be varied from a greater down to a smaller degree. The probe, therefore, controls the inclination of the container.

In the phase in which the fruit pieces start to be filled from the conveyor into the container, the probe must rest on to the bottom so as to enable unloading to be started; therefore, if the container is in a lowered position, it is raised until the contact with the probe is established;

a safety photoelectric cell 12 to prevent the fruit from being squeezed under the forward and backward translating conveyor in the case that a pile of fruit pieces fails to be detected by the proble 10 due to its being in a position too far behind; in such a case the photoelectric cell 12 will intervene to similarly cause the container to be lowered until the conveyor disengages the underlying fruit pieces.

Even if for reasons of greater simplicity Figure 3 merely illustrates a simple vertical photoelectric cell 12, it will be readily appreciated that any sensor or pair of photoelectric cells may be used in such an arrangement as to be able to detect any possible presence of heaped-up fruit pieces in a backward position with respect to the head portion of the conveyor.

For the container to be capable of being lowered, the same container is hinged with its upper front corners 20, 21 facing the conveyor on the axis A - A lying immediately under the hopper in the full backward position thereof, as this can be clearly seen in the illustrations appearing in the Figures, said axis being integral with the structure, extending horizontally and arranged transversally with respect to the feeding direction of the conveyor; as a result, a reduction in the degree of inclination of the container necessarily causes the same container to move down to a lower position, thereby lowering also the upper level of the fruit pieces laid down in the container. The photoelectric cell 12 therefore operates in parallel with the probe 10 as far as the control of the lowering motion of the container is concerned;

a collecting and unloading hopper 4 arranged on top of the conveyor 2.

Such a hopper is operated by an electropneumatic piston and has just two operating states, ie. an open state when it unloads and a closed state when the conveyor either moves forward in its translatory action and is on the contrary at a standstill as far as its fruit conveying movement is concerned or is at a standstill as far as both moving modes thereof, ie. translation and fruit conveyance, are concerned, such as for instance during the changing of a container.

Such hopper receives the fruit pieces from the conveyor and accompanies them into the container (first operating state, ie. open condition of the hopper).

In the second operating state of the hopper, the latter is closed and it therefore retains the fruit pieces that are in it during the forward translatory movement of the conveyor 2.

Anyone skilled in the art will anyway be able to readily appreciate that the above described task performed by the hoipper, ie. retaining for a certain time the fruit pieces from falling into the container, can be accomplished even by other means, such as for instance by merely stopping the movement of the conveyor belt for a definite period of time;

photoelectric cells 13 for detecting a possible presence of heaped-up fruit pieces on the hopper 4, said photoelectric cells being operated by two or more straps 14 hanging above the same hopper; when the fruit pieces pass by and fall into the container, said straps rise and then drop again down to their orginal position by the mere action of gravity, while they on the contrary remain in their raised position when the fruit pieces are held back in the hopper. At this point an opaque element 24, which is appropriately connected to said straps and is arranged between said photoelectric cells, intercepts the beam of light therebetween, thereby generating a signal that causes the conveyor to move or translate backwards, so that the fruit pieces that got stuck in the hopper are enabled to move down into the container, thereby clearing the same hopper.

The distance covered by the conveyor when carrying out such a backward translatory displacement triggered by the photoelectric cell being so engaged by the above described strap 14 owing to fruit pieces heaping up on the hopper is a pre-programmed one, as appropriately estimated in accordance with the need of reasonably ensuring that an adequate amount of fruit pieces will be enabled to be unloaded so as to unfalingly clear the same hopper.

As a result, as long as the photoelectric cell 13 is shaded, the conveyor will displace backwards. Then, as soon as the same photoelectric cell is set free again, thereby indicating that the hopper has been cleared, the conveyor kepps displacing further by a pre-programmed distance;

a photoelectric cell 15 for detecting the filling level of the container. This photoelectric cell detects possible protrusions from the plane that closes the aperture of the container and extends between the two side boards of the container. Said photoelectric cell is so arranged as to be able to move jointly with the movement of translation of the conveyor and the related hopper; it further appropriately engages a pair of rails 16, 17 that are provided close to the upper edges 22, 23 of the side boards of the container.

When the last layers of fruit pieces are laid down in the container during the final filling phase, this photoelectric cell makes sure that no piece of fruit protrudes from the aperture of the container as defined by the upper edges of the side boards thereof. If obstacles are on the contrary detected, it issues the same signal as the afore described photoelectric cell 13, which in other words causes the conveyor to accomplish a backward translatory movement; it therefore works in parallel with the photoelectric cell 13.

With reference to Figure 13, a preferred embodiment of the positioning and movement control and actuation system of the photoelectric cell 15 is described below.

A flexible element 50, which usually comprises a belt or a chain, is attached with an end portion thereof to a point 51 that is integral with the support frame of the conveyor 2, is wound round a rotating shaft 52 provided integrally on the front edge of the bin 3, is brought backwards and wound round a second rotating shaft 53 on the rear edge of the bin, and is finally bent upwards and wound round a third shaft 54, which is integral with the structure of the conveyor; it then comes down therefrom and, with its opposite end portion, it is applied to a weight 55 that is adapted to keep said flexible element always tightly stretched.

Said two front and rear

rotating shafts

52 and 53 are applied to a structure (not shown) which is firmly joined to the upper side edges of the bin; the photoelectric cell 15 is capable of sliding within an appropriate guide means and is applied to that portion of the flexible element 50 which goes from the initial point 51 to the first roller 52; the latter and the second rotating shaft 53 are firmly joined to the bin 3, in the sense that they maintain their positions at the extremities thereof, as defined and illustrated in Figure 13. It is in this way ensured that the forward and backward movement of the hopper 4 relative to the bin, being it integral with the point 51 and, as a result, with the position of thew photoelectric cell 15, causes said photoelectric cell to also "sweep" the aperture of the bin and to thereby immediately detect any possible protrusion of pieces of fruit beyond the level of said aperture.

The operation of the above described apparatus is as follows: the container, which has preferably the shape of a rather shallow box or case, is at the beginning placed or horizontally transferred on to its resting and positioning base 5; from such a position, said resting base starts then to rotate about said horizontal axis A-A extending transversally with respect to the axis along which the fruit is conveyed, while carrying along in its movement also the container placed thereon, the latter being actually rotated until it is reaches the position shown in Figure 5, ie the position of maximum rotation thereof, in which said container is tilted almost vertically, with the unloading mouth displaced forward until it almost touches the edge between the bottom of the container, which is almost vertical in this position, and the side wall 18 which is close to the unloading mouth of the hopper.

When the products are being unloaded, each one of the four afore cited

sensors

10, 12, 13, 15 is activated and delivers the corresponding signals to the central control unit, which then processes said signals and sends the corresponding output commands to the actuators governing the movement of the sliding conveyor, the position of the hopper, which may be displaced more or less backwards or forwards, and the inclination of the container, although it will be readily appreciated that the apparatus may operate with just any one or two activated sensors as well, even if the absence of one or two signals coming from the corresponding sensors will of course limit the performance capabilities of the apparatus, in that it will not be able to prevent some of the afore cited drawbacks from occurring, without this however affecting any other aspects of the operation thereof.

In detail, the operation of the apparatus takes place as follows: the conveyor, which is at a standstill at the beginning, starts its translatory movement so as to move inside the container until it reaches a point that is given by the degree of inclination of the base, as detected by an appropriate encoder and defined in the operational programme of the apparatus.

The translatory position of the conveyor and related hopper is detected by a further respective appropriate encoder.

When the conveyor reaches the position commanded by the afore cited central control unit, the hopper, which was closed as the conveyor moved forward, moves downwards and starts unloading the fruit since the conveyor now starts its fruit conveying movement.

When the hopper fills up owing to the pieces of fruit conveyed thereinto piling up on those which are already laid down in the container, there is the intervention of the afore described straps which in turn activate the photoelectric cell 13 which again causes the conveyor to trasnlate backwards; the conveyor is therefore displaced backwards and this translatory movement thereof enables the pieces of fruit to freely slide into the container. This backward movement of the conveyor covers a pre-determined distance comprised in the operational programme of the apparatus and such a procedure is repeated whenever the corresponding signal is delivered by the photoelectric cell 13.

When the conveyor, after successive backward displacements thereof, reaches then back to a ZERO position that is well-defined in and identified by the programme stored and running in the control unit, the hopper is closed, the conveyor is stopped and a forward translation movement is started to start laying down a new layer of fruit pieces, and so on according to an iterative process.

During each fruit unloading movement from the conveyor into the hopper and from the hopper into the container, also the probe 10 is operating to cause the container to be lowered, by a reduction in the degree of inclination thereof, when it detects the fruit, or causes it to rise if, when unloading begins, the fruit is not detected by said probe.

When the last layers of fruit are being laid down in the container, the photoelectric cell 15 may then start operating in view of preventing the container from being filled to an excessive extent, ie. beyond the upper edge of the two side walls thereof; this photoelectric cell practically acts in the same manner as the photoelectric cell 13, in that it causes the conveyor-hopper assembly to carry out a translatory backward movement

The end of the filling phase is determined by the sensor at the base, which detects the latter reaching its horizontal position, wheras it is the probe 10 which actually controls the resting base of the container so as to cause it to reach said horizontal position.

The purpose of the probe 10 is substantially to ensure that, at each beginning of the fruit unloading process and at each variation in the position of the hopper, a signal is generated which is adapted to bring about a self-levelling process of the apparatus.

Therefore, it is now fully apparent that both movements of the conveyor, ie. the backward and forward displacements thereof relative to the container and the fruit conveying movement, the actuation of the hopper and the inclination of the base are co-ordinated by the operational programme stored in the central control unit on the basis of the signals issuing from said sensors so that:

possible clumps forming in the hopper can be caused to clear it without any obstruction (sensor 13);
the pieces of fruit can be laid down in the container in an orderly manner, without exerting any pressure on the layer of fruit therebelow;
no fruit is laid down beyond the upper edge of the container (sensor 15),

thereby reaching the desired and afore indicated aim of filling the container in an optimum manner, while reducing the risk of damaging or spoiling the fruit to a mimimum.

The apparatus can obviously be provided with a variety of further devices that, being irrelevant to the purposes of this invention, are not dealt with here.

Furthermore, although this invention has been described with reference to an example of preferred embodiment and using a generally known terminology, it shall not be considered as being limited by this, since anyone skilled in the art is able to develop a number of variations and modifications in both the shape and the construction thereof without departing from the scope of the present invention.

Claims

Automatic apparatus for filling containers (3) with individual products, in particular vegetables or fruit, comprising.

at least a product feeding device (2) that is guided in a substantially horizontal manner and is adapted to transfer said products from an initial or loading station to a final or unloading station, said device comprising means (4) for unloading, preferably by gravity, said products into said containers;

means to drive said feeding device with a reciprocating motion parallel to the direction of feeding of such products;

at least a support structure (5) for a container, adapted to oscillate in an articulated and actuatable manner at the outlet side of said unloading means (4);

means to actuate said support structure (5) from an initial raised position, in which said container is raised so that its filling aperture is oriented toward said unloading means at a pre-selected maximum angle, to subsequent working positions in which said container assumes progressively decreasing angles, said feeding device (2) in said working positions being capable of carrying out, jointly with said unloading means (4), a forward movement into said container and a backward movement during which the products are substantially unloaded in successive layers into the container, characterized in that it further includes automatic means adapted to identify, as a generic layer of products is being laid down in the container, the projection, on a vertical plane parallel to the axis of the forward and backward movement of said feeding device, of a plurality of points of the profile of the products laid down in the previous layer, and to therefore arrange said generic layer being laid down so as to enable any possible irregularity in the surface distribution of the previous layer to be at least partially compensated for, in such a manner as to enable said individual products to be laid down onto the products therebelow by sliding smoothly thereon and not by dropping or falling down abruptly.
Automatic apparatus according to claim 1, characterized in that it is capable of identifying any possible accumulation of products in correspondence of said unloading means, and that it is further provided with means to translatory displace said unloading means in the zones of the container which from time to time ensure adequate receptivity of the heaped-up products and the consequent elimination of said accumulations.
Automatic apparatus according to claim 1 or 2, characterized in that automatic means comprise at least a first sensor (10) located under said product feeding device (2) and adapted to detect by interference the presence of products immediately below said feeding device and contained in said container.
Automatic apparatus according to claim 3, characterized in that it further comprises at least a second obstacle-feeling sensor (12) arranged on the sides of and under said unloading means (4) in an advanced position with respect to said first sensor (10), said second sensor (12) being adapted to detect the presence of products underneath said same means, and contained in said container, and arranged along a straight line extending transversally along the whole width of the container.
Automatic apparatus according to any of the preceding claims, characterized in that it comprises third sensors (13) adapted to detect the presence of loose products accumulating in correspondence of said unloading means and, when such a presence is detected, to deliver a signal adapted to cause said unloading means to be displaced backwards by a pre-determined distance.
Automatic apparatus according to claim 5, characterized in that said third sensors (13) comprise a strap (14) arranged vertically by gravity on the unloading section of said unloading means, said strap being movably hinged at its upper side to pivot about an horizontal axis that extends transversally with respect to the direction in which said products are fed, said second sensors (13) being adapted to deliver a control signal that causes said unloading means to be displaced backwards when the normally vertical position of said hanging strap is caused to rotate beyond a pre-set angle in the unloading direction of the products.
Automatic apparatus according to any of the preceding claims, characterized in that there is provided a fourth obstacle-feeling sensor (15) in sliding correspondence of the upper edges (21, 22) of the opposite side walls of said container, said fourth sensor (15) being mounted at a fixed distance from said unloading means (4), but anyway capable of rotating with the rotating movement of said container.
Automatic apparatus according to any of the preceding claims, characterized in that it is provided with central control means that is adapted to receive the signals delivered by one or more of said sensors (10, 12, 13, 15), to process said signals, even in combination with pre-defined instructions appropriately stored in said central control means, and to accordingly output resulting control signals that are adapted to determine:

the operation and/or the shutdown or standstill of said product feeding device (2);

the position and the forward and backward displacement movements of said unloading means (4);

the inclination angle of said container (3).
Automatic apparatus according to any of the preceding claims, characterized in that it is adapted to operate according to anyone of following operating conditions and modes or combination thereof:

a) - if said third sensor (13) detects an obstacle and sends a corresponding signal,

the unloading mouth is displaced backwards until said obstacle signal ceases and it is then further displaced backwards by a pre-programmed distance starting from the moment at which said signal has ceased;

b) - if the first sensor (10) sends a pre-defined proximity (or contact) signal,

the inclination angle of the container is reduced by a pre-determined value;

c) - if said fourth sensor (15) sends a pre-defined interference signal, said unloading means (4) are displaced backwards by a pre-programmed distance or, alternatively, until said interference signal is kept active;

d) - if said second sensor (12) intercepts an obstacle, it sends a pre- defined signal adapted to reduce the inclination angle of the container by a pre-determined value.
Automatic apparatus according to any of the preceding claims, characterized in that said second sensor (10) is a feeler-like probe.
Automatic apparatus according to any of the preceding claims, characterized in that said unloading means (4) comprise a hopper, the outlet mouth of which is arranged according substantially to the full width of said container.
Automatic apparatus according to any of the preceding claims, characterized in that said container is pivotally hinged with its front corners (20, 21) facing said feeding device (2) on an axis (A - A) located under said unloading means, said axis being integral with said structure (1) and extending horizontally and transversally with respect to the product conveying direction of said feeding device.