The present invention relates to a method and to a system for rotating at least one group of containers.

BACKGROUND ART

Bottling lines are known which comprises a plurality of units for carrying out respective operations on containers.

Very briefly, bottling line comprises at least a rinsing unit for rinsing containers, a filling unit for filling containers with a pourable food product, a capping unit for capping the containers, and a grouping unit for forming groups of containers.

Bottling lines also comprise an end station receiving groups of containers travelling on several, typically two, rows on an horizontal conveyor along a first horizontal direction, a sorting apparatus for sorting the groups according to a predetermined algorithm and delivering the groups to an accumulation station at which a layer of sorted groups is formed and thrust onto a palletiser.

Especially when they are rectangular, groups of containers travelling on the horizontal conveyor call for being rotated, so as to be fed to the sorting apparatus in a given position.

To this purpose, a metallic abutment element protrudes from a lateral side of the horizontal conveyor along a second horizontal direction, which is orthogonal to the first horizontal direction.

As its lateral portion strikes against the abutment element, the group of containers rotates about a third vertical direction.

Due to the fact that the rotation of the group relies on the strike onto the abutment element, it is necessary that a pre-determined portion of the lateral surface of the group impacts against the abutment element. In other words, it is necessary that the group travels onto the horizontal conveyor in a precise range of positions relative to abutment element. Otherwise, groups are, for example, prevented from striking against the abutment element and, therefore, from rotating.

Furthermore, once they have struck against the abutment element, the rotated group are set downstream from the abutment element in a variable position onto the horizontal conveyor. The variability of the position of the rotated groups may penalize the subsequent formation of the layer of the pallet in the sorting apparatus .

Finally, when they travel onto the horizontal conveyor at particularly high speed, groups may be damaged by the impact against the abutment element.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a method for rotating at least one group of containers designed to provide a straightforward, low-cost solution to at least one of the aforementioned drawbacks typically associated with known rotating method.

The aforementioned object is achieved by the present invention as it relates to a method for rotating at least one group of containers as defined in claim 1.

The invention also relates to a system for rotating at least one group of containers as defined in claim 8.

BRIEF DESCRIPTION OF THE DRAWINGS

One preferred embodiment is hereinafter disclosed for a better understanding of the present invention, by way of non-limitative example and with reference to the accompanying drawings, in which:

- Figures 1 to 4 show a system for rotating one group of containers according to the present invention in respective operative steps subsequent to another, with parts removed for clarity;

- Figures 5 and 6 are schematic view of the system of Figures 1 to ; and

- Figure 7 schematically shows the rotation of a group of containers.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to Figures 1 to 4, numeral 1 indicates a system for rotating a group 3 of containers 2.

Very briefly, system 1 is adapted to be incorporated within a bottling line.

Bottling line comprises a rinsing unit for rinsing containers 2, a filling unit for filling containers 2 with a pourable product (like a food product) , a capping unit for capping containers 2 and a grouping unit for creating groups 3 of containers 2 .

Bottling line also comprises an end unit 6 (Figure 5 ) which is located downstream from filling, capping and grouping units, with reference to the travelling direction of containers 2 within bottling line.

Containers 2 may be made, for example, of carton, glass or plastic.

In the embodiment shown, groups 3 are formed by three pairs of containers 2 . Accordingly, groups 3 have two sides 4 opposite to another and cooperating with three containers 2 , and two sides 5 which are interposed between sides 4 and cooperate with two containers 2 . As a consequence, sides 4 are longer than sides 5 .

Very briefly, end unit 6 comprises (Figure 6 ) , according to a forward direction A of containers 2 ;

- a receiving station 10 fed with groups 3 of containers 2 arranged in two rows 11 parallel to one another and travelling along direction A;

- a plurality of sorting apparatuses 12 (in the embodiment shown in number of two) for sorting groups 3 according to a pre-determined algorithm; and

an accumulation station 13 at which sorted groups 3 form a layer 30 intended to be thrust onto a palletiser.

System 1 comprises advancing means 14 for advancing groups 3 along direction A and for feeding receiving station 10 of end unit 6 with rows 11 . More precisely, advancing means 14 feed receiving station 10 of end unit 6 with groups 3 having respective sides 4 substantially parallel to a horizontal direction C orthogonal to direction A and respective sides 5 substantially parallel to direction A.

Advantageously, advancing means 14 comprise, for each row 11 to be fed to receiving station 10, :

- a conveyor 15 onto which a first portion 19a of group 3 may move along direction A;

- a conveyor 16 onto which a second portion 19b of group 3 may move along direction A;

- a motor 17 (Figure 5) operatively connected to conveyor 15 and controllable for moving conveyor 15 at least at a first speed value; and

- a motor 18 (Figure 5) operatively connected to conveyor 16 and controllable for moving conveyor 16 at least at a second speed value which is different from first speed value, so as to rotate groups 3 about a direction B which is transversal to direction A.

Conveyor 15 is placed beside to conveyor 16, so that portions 19a, 19b substantially correspond respectively to a first and a second half of group 3 to be rotated.

In the embodiment shown, conveyors 15, 16 are belt conveyors .

In particular, direction B is orthogonal to direction A and vertical .

Motors 17, 18 can drive respective conveyors 15, 16 at a variable speed.

System 1 further comprises:

a pair of inlet conveyors 20 for conveying respective groups 3 to respective conveyors 15, 16;

- a pair of outlet conveyors 21 for conveying respective groups 3 coming out from conveyors 15, 16 to receiving station 10;

- a pair of sensors 22 (Figure 5) for detecting the angle of rotation of groups 3 which are rotated onto respective conveyors 15, 16 about direction B ; and

- a control unit 23 receiving a signal generated by sensors 22 and associated to the angle of rotation of relative groups 3 which are rotated onto corresponding conveyors 15, 16 about relative directions B .

Control unit 23 controls relative motors 17, 18 on the basis of the signal received by relative sensor 22 .

More precisely, each control unit 23 normally controls respective motors 17, 18 in such a way that corresponding conveyors 15, 16 advance at a third speed value.

A software program may be loaded onto control unit 23 . When the software program is executed, control unit 23 varies the speed value of conveyors 15, 16.

More precisely, control unit 23 has stored in memory the relevant data of groups 3 , e.g. the weight, the length of sides 4 and the length of sides 5.

When it is necessary to rotate group 3 about direction B , control unit 23 controls respective motors 17 , 18 , so that:

- each motor 17 accelerates respective conveyor 15 at the first speed value which is higher than the third speed value;

- each motor 18 decelerates respective conveyor 16 at the second speed value which is lower than the third speed value.

In particular, each pair of conveyors 15 , 16 convey relative group 3 parallel to direction A along a relative path P.

Each path P comprises :

- an initial portion Q;

- a central portion R along which group 3 is rotated about direction B; and

- a final portion S.

Control unit 23 drives conveyors 15 , 16 at a constant third speed value when group 3 is conveyed along initial portion Q and final portion S.

Differently, in case that it is necessary to rotate group 3 , control unit 23 varies the speed of relative conveyors 15 , 16 when group 3 is conveyed along relative central portion R.

In this way, system 1 is prevented from rotating group 3 before it is wholly onto such relative conveyors 15 , 16 and when it is being discharged from relative conveyors 15 , 16 .

In other words, when group 3 is rotated, it travels at the third speed value for such certain length corresponding to relative portions Q, S onto relative conveyor 15, 16 before and after the rotation.

Each sensor 22 substantially comprises:

- a transmitter 24 which emits -an electromagnetic radiation along direction C orthogonal to directions A,

B; and

- a receiver 25 which is arranged on the opposite side of transmitter 24 with respect to relative conveyors 15, 16 and is adapted to receive the electromagnetic radiation generated by transmitter 24.

In the embodiment shown, each transmitter 24 is a light emitting diode which emits a plurality of electromagnetic rays.

When it passes in front of relative transmitter 24, each group 3 in rotation interrupts the transmission of electromagnetic rays from relative transmitter 24 to relative receiver 25.

In particular, each transmitter 24 and receiver 25 extend along direction A for a length which corresponds to the length of relative portion P.

On the basis of the number of electromagnetic rays interrupted by each group 3 along portion R, relative sensor 22 measures distance D parallel to direction A between the most forward point F with reference to direction A and the most backward point G with reference to direction A of each group 3 in rotation (Figure 7) .

When relative distance D equals a given value stored in control unit 23, each sensor 22 detects that a rotation of a certain angle has been completed. For example, when such distance D equals the length of side 5, sensor 22 detects that relative group 3 has been rotated for 90 degrees (Figure 7) .

The operation of system 1 will be described in the following description with reference to only one conveyor 15, to only one conveyor 16, only one conveyor 20 , to only one conveyor 21 , and to only one sensor 22 .

The operation of system 1 will also be described in the following description with reference to an initial configuration, in which sides 4, 5 are parallel respectively to directions A, C.

Conveyor 20 feeds group 3 to conveyor 15 along direction A.

Conveyors 15, 16 normally advance respectively portions 19a, 19b of group 3 at the third speed value along path P.

When it is necessary to rotate groups 3 travelling onto conveyor 15, e.g. for arranging sides 4, 5 parallel to direction C, A, control unit 23 controls motors 17, 18 so as to accelerate conveyor 15 from the third to the first speed value and to decelerate conveyor 16 from the third to the second speed value.

As a consequence, portion 19a of group 3 travelling onto conveyor 15 is accelerated while portion 19b of group 3 travelling onto conveyor 16 is decelerated.

Accordingly, the friction forces between conveyor 15, 16 and portions 19a, 19b cause the clockwise rotation of groups 3 about direction B.

Control unit 23 controls motors 17 , 18 , so that the speed the angular speed of group 3 about direction B is faster as in the initial phase of such rotation and slower in the final phase of such rotation.

As it rotates about direction B, group 3 interrupts the transmission of the electromagnetic radiation from transmitter 24 to receiver 25 .

Accordingly, sensor 22 detects distance D along direction A between:

- the most forward point F of group 3 in rotation with reference to direction A; and

- the most backward point G of group 3 in rotation with reference to direction A.

With reference to Figures 5 and 7 , such distance D varies from the length of sides 4 to the length of sides 5 .

Sensor 22 detects that the rotation of group 3 about direction B is completed, i.e. the group 3 has rotated of ninety degrees, when distance D along direction between the most forward and the most backward points F, G of group 3 in rotation with reference to direction A equals the length of side 5 .

At this stage, control unit 23 controls motor 17 , 18 so that conveyors 15 , 16 advance rotated group 3 at the third speed value.

It is important to point out that control unit 23 controls motor 17 , 18 so that conveyors 15 , 16 are respectively accelerated and decelerated only when group 3 is travelling along portion R of path P.

As group 3 travels along portion Q and S of path P, motors 17 , 18 drive relative conveyors 16 , 17 at the third speed value.

Finally, group 3 is fed to receiving station 10 of end unit 6 .

From an analysis of the features of method and system 1 for rotating groups 3 of containers 2 made according to the present invention, the advantages it allows to obtain are apparent.

In particular, the rotation of groups 3 is due to the fact that conveyor 15 travels at a first speed value which is greater than the second speed value at which conveyor 16 travels.

Due to the fact that rotation of groups 3 no longer relies on an impact against an abutment element, system 1 can rotate groups 3 for a wide range of position of such group 3 . Accordingly, the flexibility of system 1 is particularly high.

Furthermore, the rotation of groups 3 about direction B is highly precise and does not affect the position of such groups along direction B. As a result, groups 3 are fed to end unit 6 in a very precise position.

Finally, even when they are conveyed at a very high speed, groups 3 may be rotated without any risk of being damaged. Finally, it is apparent that modifications and variants not departing from the scope of protection of the claims may be made to method and system 1 for rotating groups 3 of containers 2.

In particular, system 1 could comprise only one conveyor 15, only one conveyor 16, only one conveyor 20, only one conveyor 21, and only one sensor 22.