FILLING UNIT

The present invention relates to a filling unit in accordance with the introduction to the main claim. More particularly it relates to a unit for filling first bags, usually of mesh, with a predetermined number of smaller second bags in which loose products are prepackaged and within which they are freely movable. In particular, the first bags can be of any material, while the second bags can be of mesh plus band, of GIRPLUS or VERTBAG or CARRY FRESH type, or of PE or PP film. The loose products contained in the smaller second bag can be for example citrus fruits such as oranges, lemons, mandarins, or vegetables such as potatoes or onions. These products are currently packaged for large-scale distribution in large bags containing about 10 bags of smaller dimensions. For example 10 small bags each of 2.5 kg are inserted into a large 25 kg bag to facilitate their transport. The filling operation is currently performed manually. An object of the invention is therefore to provide a bag filling unit which enables the currently manual operation to be automated.

This and further objects are attained by a bag filling unit in accordance with the accompanying claims. Advantageously the bag filling unit of the present invention enables first bags fed discontinuously to be filled with prepackaged second bags originating from a continuous feed line.

A unit of the present invention enables the number of small dimension bags inserted into those of larger dimensions to be counted with extreme accuracy. A further advantage of the present invention is that it enables homogeneous bag filling, resulting in space saving and minimizing final bag volume. Further characteristics and advantages of the invention will be apparent from the description of a preferred but non-exclusive embodiment of the bag filling

unit, illustrated by way of non-limiting example in the accompanying drawings, in which:

Figure 1 is a schematic plan view of a bag filling unit according to the present invention; Figure 2 is a schematized front view of the device of Figure 1 ;

Figure 3 is a schematic side elevation of the device of Figure 1 ;

Figure 4 is a schematic plan view of an alternative embodiment of a bag filling unit according to the present invention;

Figure 5 is a schematized front view of the device of figure 4; and Figure 6 is a schematized side elevation of the device of figure 4.

With reference to said figures, these show a bag filling unit indicated overall by

1.

The unit 1 is inserted into a common production line presenting a feeder 2 of small-dimension bags 3 filled with food products. In the illustrated example the small-dimension bags are filled with potatoes.

The feed line comprises a known feed belt 2 feeding the filling unit of the present invention. The unit 1 cooperates downstream with a known device 4 for forming and closing known mesh bags 6, and which feeds these bags to the unit individually. The mesh bags 6 are unwound from a roll 5, and are formed from 2 facing mesh layers 6A, 6B sewn along a horizontal continuous line 6C positioned at the bottom of said bags 6 and along vertical lines 6D, 6E which laterally bound each bag 6.

These bags 6, resting on a conveyor belt 8 for the bags 6, advance individually such that a bag remains (open in usual manner) below a dispensing region 9 of the filling unit 1 until completely filled.

The filled bag 6 is then moved into a position in which it is sewn along its mouth and is separated from the remaining bags by a cut made between two side seams 6E' 6D of two neighbouring bags.

Although from the aforegoing description the formation and closure device is totally conventional, it advantageously presents a vibrator 10 positioned below the second conveyor belt 8, which raises and lowers it at regular intervals to render the distribution of the small bags 3 homogeneous within the bag 6. The vibrator 10 comprises a gearmotor 11 , with a pair of arms 12 keyed onto its shaft. A pair of rollers 130 are pivoted to each end of and between these arms, parallel to the shaft 10a. Rotation of the gearmotor 11 causes the arms to rotate and intercept the elastic belt 8 of the conveyor by means of the rollers 130, to raise it and then let it fall alternately. This causes a vibratory movement, resulting in homogeneous filling of each bag 6.

In this respect, each small-dimension bag 3 contains prepackaged loose products. These products are hence freely movable within the bag. Essentially, when the small bag 3 is rested on any surface, the products in its interior rest on this surface to cause the bag to assume a shape similar to that of the surface on which they rest. Lateral expansion of the small bag is limited by the tension of the mesh which maintains the products grouped together. Hence a vibrator acting on the conveyor belt 8 for the bags 6 enables a number of superposed small bags 3 to lie uniformly in the bag 6, to enable this latter to occupy a smaller volume. The filling unit 1 comprises a pair of conveying lines 73, 74 comprising adjacent conveyor belts 12, 13, each independently drivable by means of a gearmotor (not shown), they being separated from each other by a baffle 14 and laterally bounded by walls 15, 16. The exit of the feed belt 2 is positioned above this baffle (see Figure 2). A selector 18 is hinged to the baffle 14 below the feed belt 2 and is moved by an actuator 19 between a first selection position in which it guides a small bag falling on it onto the first belt 12, and a second selection position in which it guides this small bag onto the second belt 13.

In this manner the selector distributes the small bags 3 arriving from the feed belt 2 alternately between the first belt 12 and the second belt 13. The movement of the selector 18 is controlled by third photoelectric cells 20, 21. When a small bag 3 falls onto the first conveyor belt 12 after sliding onto the selector 18 (for example in the first selection position), the small bag lands in front of the third photoelectric cell 21 which, being obscured, causes the actuator 19 to move the selector 18 into its second selection position. The next small bag 3 which arrives from the feed belt 2 consequently falls onto the second belt 13 and so on. Said first conveyor belt 12 and second conveyor belt 13 each have a length such as to house two small bags 3 in a third waiting position III and in a second waiting position II. The presence or absence of the small bags 3 on each of said belts 12, 13 in said third waiting position III is monitored by the said photoelectric cells 20, 21 , while the presence or absence of a bag in said second waiting position Il is monitored by second photoelectric cells 24, 25. Each of the two conveyor belts 12, 13 opens onto an inclined ramp 30, 29 defining a first waiting position I ₁ monitored by a first photoelectric cell 27, 26; the two ramps or inclined surfaces each act as a dispensing region 9, below which an open bag 6 is positioned to receive in its interior the smaller bags 3 falling from the dispenser unit 1. Both the ramps open into the same bag, but in different positions.

At the exit of each ramp an interceptor means 31 , 32 is positioned, comprising a profiled shutter 33, 34 hinged about a rotation axis A. Behind each shutter 33, 34 a pneumatic cylinder 36, 37 is positioned, movable between a first position in which it blocks rotation of said shutter 33, 34, and a second position in which it frees rotation of said shutter 33, 34, to hence enable a small bag 3 lying on the ramp 30, 29 in front of the shutter 33, 34 to either remain at rest on the ramp or to fall into the bag 6 by moving the shutter by the action of its

weight.

A blade 40 positioned in front of a sensor 41 is torsionally associated with each shutter. The rotation of the shutter, caused by the weight of a small bag 3, causes the blade to move out of the area of influence of the sensor, which hence senses the passage of a small bag 3, so enabling the number of small- dimension bags 3 inserted into the bag 6 to be counted accurately on each line. The shutter 33, 34 advantageously has a weight and shape such as to open only when the weight acting on it exceeds a certain limit. This prevents the shutter from opening if for example a single potato is present, having accidentally escaped from one of the small bags 3, so avoiding counting errors. The shutter 33, 34 is also shaped such as not to enable the small bags to become trapped.

A rubber insert 48 is also present on each ramp 30, 29 in a portion of contact between the ramp and shutter, to damp the shutter closure movement and prevent possible rebounds which could result in counting errors for the small bags 3 falling into the bag 6.

Aligned with and downstream of the baffle 14 a separator 50 of elongate shape is provided, movable vertically along a guide 51 by an actuator, not shown. The separator 50 is lowered into the open bag 6 while the bag is still moving towards the dispensing position 9, and helps to stretch and open it to enable the small bags 3 to fall more easily into the bag 6. The separator 50 is also very useful in separating the bag into two regions or columns 70, 71 , each fed independently by the first and second conveyor belt via the respective shutter. Once the small bags are dispensed one to the right and one to the left of the separator, this latter rises slightly to enable two aligned bags to make lateral contact. The same happens as the successive small bags 3 are inserted until the bag 6 is filled. In this manner the distribution of the small bags 3 within the bag 6 is very homogeneous and any space wastage, due to undesirable

superposing of the small bags 3, is limited. Advantageously, before the last two small bags 3 are dispensed, the separator 50 is extracted from the bag 6 to enable the just filled bag 6 to be quickly shifted. The unit 1 operates in the following manner. The forming and closing device 4 firstly positions a bag 6 below the dispensing region. The separator 50, as stated, is lowered into the bag before this latter reaches the bottom of the dispensing region 9. The feed belt continuously feeds the small bags 3 to the filling unit 1. The selector 18 alternately feeds one bag onto the first conveyor belt 12 and one onto the second conveyor belt 13, which move continuously to feed these small bags onto the respective ramps or inclined surfaces 30, 29. The weight of the thus conveyed small bags 3 causes the corresponding shutter 33, 34 to open, the sensor 41 of each shutter also counting the number of small bags 3 fed into the bag 6. The small bags 3 fall controlled by the separator to fill each of the columns 71 , 72 of the bag 6.

When one of the columns is full, for example the right column (the example is however identical for the left column, but with relation to the components of the second conveyor belt 13), the pneumatic cylinder 36 above that column blocks the relative shutter 33 to prevent a further small bag 3, carried by the first conveyor belt 12, from falling into the bag. The small bag 3 resting against the shutter 33 hence occupies the first waiting position I. The photoelectric cell 27 senses the presence of the small bag 3, but the conveyor belt 12 is not halted. This first conveyor belt is halted only when a possible further small bag 3 transits in front of the second photoelectric cell 25. A train of small bags is thus created, waiting to be inserted into the bag 6.

When the third waiting position on both belts is occupied (photoelectric cells 21 and 20 obscured), the filling unit 1 is saturated and the feed belt is halted as an

emergency condition.

However the speed of the feed belt is such as to virtually never reach an emergency blockage given that the accumulation positions (three for each belt) easily enable the column to be filled. Advantageously, to eliminate any counting errors a brush is provided above the conveyor belt 12, 13 in proximity to the second waiting position II, and is movable between a first position in which it is spaced by a few centimetres from the belt, and a second position in which it is virtually resting on it. This brush is lowered when the cylinder 36 is activated and the photoelectric cell 27 senses a small bag 3 in the first position.

The purpose of this brush, which is raised with a certain delay after the cylinder 36 is deactivated, is to slow down any small bag 3 arriving in front of the photoelectric cell 25 of the second position Il a few moments after the cylinder 36 is deactivated and with the conveyor belt still moving. Such a bag, arriving on the ramp 30 at speed, could pass below the shutter 33 when it is still open by the passage of the previous bag, and hence not be counted. Instead, the brush 60 intercepts this possible small bag, to create between the previous bag and the intercepted bag a time interval such as to enable this latter to be correctly counted. The accumulation positions (six in total) are also necessary to allow the automatic replacement of the bag 6 by enabling the feed belt 2 to continuously provide the small bags 3. In practice, when a bag is full (for example 5 bags per column) the pneumatic cylinders which block the shutters 33, 34 are operated and the small bags 3 begin to accumulate in the aforedescribed manner. When the bag arrives in position the two cylinders are released. The bags present in the first waiting position I of each belt fall into the bag by pushing the shutters 33, 34. As soon as the photoelectric cells of the first position 27, 26 of each belt are freed, the first and second conveyor belt (if at

δ rest) start operating, to push any small bags 3 present in the second positions Il into the bag 6.

Advantageously, this system enables the exact number of small bags 3 dispensed into each bag 6 "column" defined by the separator 50 to be counted with high accuracy. In this respect, between the successive small bags 3 present in the accumulation positions there is always a certain space enabling the shutter 33 to accurately count the small bags 3 which transit below it. This system also enables the two columns 71 , 72 of an individual bag to be filled independently, to hence ensure, for example, that in a bag 6 in which a total of ten small bags 3 are required, these do not become distributed asymmetrically within the bag 6.

It should be noted that the photoelectric cells have a controlling rather than counting function, and serve to control the accumulation function. It should also be noted that the photoelectric cells do not count by counting the strip-type label which is present in certain types of such packages or, in the case of onions, by counting their leaves.

Modifications and variants are possible in addition to those already described, for example more waiting positions can be provided by providing longer belts, or several conveyor belts in series. More than two conveyor belts can also be positioned side by side, to feed into a bag 3 with several columns of products. In that case two or more separators must be present to form the necessary number of columns.

The control logic for the selector 18 can also be optimised. If one of the two columns is full, this selector can be left at rest in the position such as to fill that column which has not yet been filled.

The feed can take place either from the right or from the left, or a feed from the rear can be used with two belts and a chute to slide the package onto the belts 31 and 32, or with a central belt from the rear along the middle of the belts 31

and 32, at the end of which there is a container which opens each time the shutter is in a position allowing the small bag to fall onto the belts 31 and 32. An alternative embodiment of the unit of the present invention is shown in Figures from 4 to 6, and is particularly suitable for filling containers 6A of any type, whether of fabric, cardboard or plastic, with a plurality of articles 3A of any kind, of which however a predetermined number are to be inserted into said container 6A.

The unit 1 shown here is substantially similar to that previously described, with the exception of some modifications made to adapt this unit to manipulate articles of dimensions, weights and characteristics different from the previously described second bags. Consequently said figures use the same reference numerals as those previously used, with no description given of the identical mechanical parts. This different embodiment is particularly suitable for counting small-dimension articles, such as plastic connectors for pipes of different diameters. These connectors differ from the articles counted by the preceding unit substantially by their different shape and different weight.

As in the preceding case, in this embodiment the feeder 2 comprises a conveyor belt 2 carrying on its surface a plurality of support elements 200 spaced apart in a regular manner and lying transversely to the belt travel direction. Said support elements are fixed to the conveyor belt. As can be clearly seen in Figure 4, these present a first portion 200A and a second portion 200B of substantially parallelepiped shape spaced apart by a space 200C. Positioned above the belt there is a first brush 201 with its bristles parallel to the support elements. The brush bristles have a length such as to intercept the upper portion of the support elements when these pass below the bristles. A second brush, which may or may not be motor-driven, is also provided perpendicular to the first and positioned such that its bristles, during belt

movement, pass into the space 200C provided between the first and second portion of the support elements.

The brushes and the space 200C are positioned such that in passing below the brushes, the connectors become distributed such as to rest on the front of each support element. The second brush 202 is provided to free any connectors which remain blocked between the two portions of the support element. It should be noted that, for simplicity, in the figures the brushes 201 and 202 are shown in proximity to the end of the conveyor belt, whereas when in use they are actually positioned spaced from the final end of the belt. The order of the brushes 201 and 202 can also be reversed, depending on the particular case. A further machine modification exists with regard to the photoelectric cells which control the selector 18. In the preceding embodiment a single photoelectric cell 20, 21 was provided to monitor the presence or absence of the bag in the waiting or accumulation position III for each line 73, 74. To adapt the reading to the small dimensions of the articles to be cleared, four or more photoelectric cells are provided, some grouped in the positions represented by the reference numeral 21A, B and some located in the positions indicated in the figure by the reference numeral 2OA, B. With the photoelectric cell arrangement, the selector 18 can be controlled with maximum precision, to detect in all cases the presence or absence of an article 3.

Moreover, to define each waiting position I, II, III along the two lines 73, 74, a further two brushes 6OB, 61 B are provided, positioned between the waiting positions Il and III, to prevent the connectors from "jumping" from one position to the other after being distributed to one of the two lines by the conveyor belt 2. These further two brushes, as those which separate the waiting position I from the waiting position II, are movable vertically above the belt under the control of the unit control logic (they being adjustable in height), and in particular they are lowered as soon as the photoelectric cells 24, 25 sense the

presence of a connector in the second waiting position II. Because of the small weight of the connectors, in the currently described embodiment two further modifications are introduced in relation to the movement of the interceptor means. A counterweight of adjustable position is associated with each of the profiled shutters 33, 34. The counterweight 210, 211 reduces the force required to open the profiled shutter, to hence enable the fairly lightweight articles represented by the said plastic connectors to be counted. Said shutters 33 and 34 are also provided with a further pneumatic cylinder 204, 205 for controlling their opening. In this respect, even for very light articles, when the conveyor belts 12, 13 are in movement the inertial force or "momentum" possessed by the articles present on the belts is sufficient to open the profiled shutters (provided the counterweights are properly adjusted) and enable correct counting of the articles which fall into the container. In contrast, when the unit is waiting for a new container 6 to be brought into the dispensing position and the article 3 to be dispensed is at rest in the first waiting position I (photoelectric cell 24, 25 active and cylinder 36, 37 closed), even if the cylinder 36, 37 is deactivated the article weight is insufficient to open the shutter 33, 34. Consequently the cylinder 204, 205 is activated to automatically open the shutter 33, 34 and hence enable the article 3 to be dispensed into container 3 and be counted.

A further photoelectric cell is also introduced into the control arrangement for the container 6, to sense if the bag is over-full.

Finally, all those metal parts of the unit in question which when in use can come into contact with the articles with which said container is filled are covered with anti-abrasive rubber material.

The operation of the unit in question is similar to the preceding, the only differences being in the control, the computerized logic of the unit and the structure of the shutters and the means for opening them, due to the small

weight of the articles with which the said containers are to be filled. In the present text reference has been made to articles with which to fill the containers 6 or first bags. These articles can be of any type, shape or weight. In the same manner the containers 6 can be cloth or plastic bags, cardboard or plastic boxes, envelopes, etc.

In the aforegoing description photoelectric cells have been defined to monitor the presence or absence of an article in the first waiting position I in front of the shutter, in the central second waiting position III or in the third waiting position III, directly below the selector 18. For each position one or more than one of such photoelectric cells can be provided, in order to also be able to read the presence of articles of considerably different dimensions.