Method of controlling a conveyor system and a conveyor system

1 . A conveyor system containing at least two variable speed conveyors connected in series and at least one controller, the first conveyor being configured to be placed in series with a preceding start conveyor, downstream which the system is attached, and the last of said at least two conveyors being configured to be placed in series with a target conveyor upstream which the system is attached,

the start conveyor outputting batches of product at a start speed V 0 , and the target conveyor receiving the batches of product at a target speed Vt, the target speed Vt being lower than the start speed V 0 ,

and wherein the controller is communicatively connected to the first variable speed conveyor and to each of at least the second variable speed conveyor,

wherein in the conveyor system each successive conveyor is shorter, and at least one controller is configured so as,

when the start conveyor operates at the start speed V 0 ,

to operate the first variable speed conveyor in the first step at a high speed of the first conveyor VH 1 greater than the start speed V 0 , thereby transferring a batch of product from the start conveyor to the first variable speed conveyor, at the same time increasing a distance between rows of products in the batch;

to operate in the second step at least the second and subsequent variable speed conveyor at a high speed of the subsequent conveyor (VH 2 , VH 3 , . . . ), the high speed of the subsequent conveyor (VH 2 , VH 3 , . . . ) being greater than the high speed of the corresponding upstream conveyor (VH 1 , VH 2 . . . );

after the batch of product has fully departed from the start conveyor onto at least the first variable speed conveyor, in the third step, to decrease the speed of the first variable speed conveyor to a low speed of the first conveyor VL 1 , the low speed VL 1 of the first conveyor being lower than the target speed (Vt); and

after the batch of product has fully departed from each conveyor of the system onto its downstream conveyor (conveyor, in the fourth and subsequent step, to reduce the speed of said downstream variable speed conveyor belonging to the system to a low speed of each its downstream conveyor VL 2 , VL 3 , . . . , the low speed of said each its downstream conveyor being less than the target speed (Vt) but greater than the low speed (VL 1 , VL 2 , . . . , ) of its upstream conveyor in order to transfer the batch of product from the first variable speed conveyor to at least the second variable speed conveyor and then to the target conveyor so that on the target conveyor the rows of products coming from the same batches and different batches have approximately the same distance.

2 . The system according to claim 1 , wherein when the system contains only the first conveyor and the second conveyor the at least one controller is configured

to set the speed of the first conveyor and the second conveyor in the first step in such a way, that

in a first period t 1 P 1 the first conveyor operates at high speed VH 1 in fast mode and the second conveyor operates in slow mode at low speed VL 2 , then after the first period of t 1 P 1 ,

in the second step, in such a way that in a second period t 1 P 2 , the first conveyor continues to operate at high speed VH 1 in fast mode and the second conveyor continues to operate at high speed VH 2 in fast mode, wherein the relationship between these speeds is described as follows: VP 0 <VH 1 <VH 2 , where VP 0 is the speed of the start conveyor preceding the conveyor system; and

in the third step in such a way that after the first conveyor and the second conveyor have moved a distance equal to the sum of their lengths L 1 +L 2 , within a time t 1 P 1 +t 1 P 2 equal to the sum of the first and second periods, in a subsequent third period t 2 P 1 , the first conveyor continues to move at the speed VL 1 and the second conveyor continues to move at the speed VH 2 ,

while in a fourth period, in such a way that after the third period t 2 P 1 , in the fourth period t 2 P 2 the first conveyor continues to move at the speed VL 1 and the second conveyor continues to move at the speed VL 2 , the relationship between these speeds being described as follows: VL 1 <VL 2 <Vt, where Vt is the speed of the target conveyor.

3 . The system according to claim 2 , wherein the system includes at least a third conveyor which speed is constant and equal to the speed of the target conveyor.

4 . The system according to claim 2 , wherein the system includes at least a third conveyor which speed is constant and less than the speed of the target conveyor.

5 . The system according to claim 1 , wherein each conveyor includes a belt placed on elongated rollers attached to a support frame, to which an axle connected by a drive belt to the rollers and connected to a servomotor, is attached.

6 . The system according to claim 1 , wherein said controller is connected to other controllers and counters controlling at least the start conveyor and the target conveyor.

7 . The system according to claim 1 , wherein the length of the first conveyor is L 1 =VL 1 *Tp, and the length of the second conveyor is L 2 =VL 2 *(L 1 /VH 1 ), where Tp is the time the products are pressed by the press.

8 . The system according to claim 1 , wherein the speed VH 1 is set according to a press speed V 0 and is greater than the press speed V 0 by less than 15%.

9 . A method of controlling a conveyor system, wherein the conveyor system includes at least two variable speed conveyors connected in series and at least one controller, the first conveyor being configured to be placed in series with a proceeding start conveyor, downstream which the system is attached, and the last of said at least two conveyors is configured to be placed in series with a target conveyor, upstream which the system is attached,

the start conveyor outputting batches of product at a start speed V 0 , and the target conveyor receiving the batches of product at a target speed Vt, the target speed Vt being lower than the start speed V 0 ,

and wherein the controller is communicatively connected to the first variable speed conveyor and to each of at least the second variable speed conveyor, and the method is wherein:

in the conveyor system, each successive conveyor is shorter, and when the start conveyor operates at the start speed V 0 ,

in the first step the first variable speed conveyor is controlled at a high speed of the first conveyor VH 1 greater than the start speed V 0 , thereby transferring a batch of product from the start conveyor to the first variable speed conveyor, while increasing a distance between the rows of products in the batch;

in the second step, at least a second variable speed conveyor is controlled at a high speed of the subsequent conveyor (VH 2 , VH 3 , . . . ), the high speed of the subsequent conveyor (VH 2 , VH 3 , . . . ) being greater than the high speed of the corresponding upstream conveyor (VH 1 , VH 2 . . . );

in the third step, after the batch has fully departed from the start conveyor onto at least the first variable speed conveyor, the speed of the first variable speed conveyor is reduced to a low speed of the first conveyor VL 1 , the low speed VL 1 of the first conveyor being lower than the target speed (Vt) and

in the fourth step, after the batch has fully departed from each conveyor of the system onto its downstream conveyor, the speed of this downstream variable speed conveyor belonging to the system is reduced to a low speed of each said downstream conveyor VL 2 , Vl 3 , . . . , the low speed of that each succeeding conveyor being less than the target speed (Vt) but greater than the low speed (VL 1 , Vl 2 , . . . , ) of the preceding conveyor to transfer a batch of product from the first variable speed conveyor to at least the second variable speed conveyor and then to the target conveyor so that on the target conveyor the rows of products coming from the same batches and different batches have approximately the same distance.

10 . The method according to claim 9 , wherein when the system contains only the first conveyor and the second conveyor,

wherein the speed of the first conveyor and the second conveyor is set in such a way that

in the first step, during a first period t 1 P 1 , the first conveyor operates at a speed VH 1 in fast mode and the second conveyor operates at a speed VL 2 in slow mode, then after the first period t 1 P 1 ,

in the second step, in a second period t 1 P 2 , the first conveyor continues to operate at the speed VH 1 in fast mode and the second conveyor continues to operate at the speed VH 2 in fast mode, the relationship between these speeds being described as follows: VP 0 <VH 1 <VH 2 , where VP 0 is the speed of the conveyor preceding the conveyor system and

in the third step, after the first conveyor and the second conveyor have moved a distance equal to the sum of their lengths L 1 +L 2 , within a time t 1 P 1 +t 1 P 2 equal to the sum of the first and second periods, in a subsequent third period t 2 P 1 , the first conveyor moves at the speed VL 1 and the second conveyor continues to move at the speed VH 2 , whereas

in the fourth step after the third period of t 2 P 1 , in a fourth period of t 2 P 2 , the first conveyor continues to move at the speed VL 1 , and the second conveyor moves at the speed VL 2 , the relationship between these speeds being described as follows: VL 1 <VL 2 <Vt, where Vt is the speed of the target conveyor.

11 . The method according to claim 10 , wherein the system includes at least a third conveyor whose constant speed is set to the speed of the target conveyor.

12 . The method according to claim 10 , wherein the system includes at least a third conveyor whose constant speed is set to a lower speed than that of the target conveyor.

13 . The method according to claim 1 , wherein the length of the first conveyor is L 1 =VL 1 *Tp, and the length of the second conveyor is L 2 =VL 2 *(L 1 /VH 1 ), where Tp is the time for pressing the products by the press.