Dosage control in the manufacture of tires

1. A method for creating batches of unvulcanized rubber before mixture in a rubber mixer, including selecting at least one batch for mixing in the rubber mixer, wherein each batch corresponds to a selection of uncured rubber bales (A I , B I , C I ) that correspond to natures (A, B, C) of rubber composition having predetermined characteristics, comprising the steps of:

providing a supply station where the uncured rubber bales (A I , B I , C I ) are supplied from the corresponding natures (A, B, C);

selecting uncured rubber bales (A I , B I , C I ) from natures (A, B, C) and in a predetermined proportion corresponding to a selected batch at the supply station;

providing a cutting station for cutting at least one uncured rubber bale (A I , B I , C I ) into pieces (A IJ , B IJ , C IJ );

providing a transport system that feeds the cutting station and transfers the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ) to the rubber mixer;

weighing the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ) to obtain a sum of a weight of the uncured rubber bales (A I , B I , C I ) and a weight of the pieces (A IJ , B IJ , C IJ );

comparing the sum obtained with a required weight of the selected batch, which is created by mixing different kinds and different grades of elastomers; and

obtaining, in a proportion corresponding to the predetermined proportion, a target weight to attain a difference between the sum obtained and the required weight of the selected batch,

wherein the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ) are transported between the supply station, the cutting station and the rubber mixer according to a sequence determined by the equivalence between the required weight of the selected batch and (a) the weight of the uncured rubber bales (A I , B I , C I ) or (b) a sum of the weight of the uncured rubber bales (A I , B I , C I ) and a weight of the pieces (A IJ , B IJ , C IJ ), and

wherein the step of obtaining a target weight further comprises the following steps:

providing a reference rubber bale (R) of a nature (A, B, C) and a predetermined proportion that corresponds to a batch at the bale supply station, the reference rubber bale (R) having a predefined weight and a predefined length (L) between one end (R L ) and an opposite end (R L′ ); and

determining a cutting length (L C ) and a cutting position (P) of a learning cut of the reference rubber bale (R) that are required to obtain the required weight of the selected batch.

2. The method of claim 1 , wherein the step of determining the cutting length (L C ) and the cutting position (P) comprises the following steps:

adjusting a position of the reference rubber bale (R) until the opposite end (R L′ ) is brought into contact against a side of a blade (Q) that performs the step of cutting the reference rubber bale (R) at the cutting position (P);

weighing the reference rubber bale (R);

calculating the cutting length (L C ) and the cutting position (P) of the learning cut using a weight of the reference rubber bale (R), which is either the predefined weight or the weight obtained by weighing the reference rubber bale (R);

cutting the reference rubber bale (R) at the cutting position (P) of the learning cut; and

weighing a first piece (R 1 ) that is obtained by cutting the reference rubber bale (R) at the cutting position (P) to obtain a real weight of the first piece (R 1 ).

3. The method of claim 2 , wherein the step of adjusting the position of the reference rubber bale (R) is performed by a linear actuator that contacts the end (R L ).

4. The method of claim 2 , further comprising the steps of:

calculating a cutting length (L C′ ) and a cutting position (P+1) of a successive cut using the weight and a length (L R1 ) obtained from the first piece (R 1 ) and a target weight of a complementary piece (R 2 );

cutting the reference rubber bale (R) at the cutting position (P+1) of the successive cut; and

weighing the complementary piece (R 2 ) that is obtained by cutting the reference rubber bale (R) at the cutting position (P+1) of the successive cut to obtain a real weight of the complementary piece (R 2 ).

5. The method of claim 4 , further comprising the steps of:

calculating a cutting length (L C″ ) and a cutting position (P+2) of a final cut using the weight and a length (L R2 ) obtained from the complementary piece (R 2 ) and a target weight of a final piece (R 3 );

cutting the reference rubber bale (R) at the cutting position (P+2); and

weighing the final piece (R 3 ) that is obtained by cutting the reference rubber bale (R) at the cutting position (P+2) to obtain a real weight of the final piece (R 3 ) remaining after the complementary cut.

6. The method according to claim 5 , wherein the step of determining a cutting length and a cutting position is performed iteratively until a sum obtained of the weight of the uncured rubber bales (A I , B I , C I ), the weight of the pieces (A IJ , B IJ , C IJ ) and a weight of the pieces (R 1 , R 2 , R 3 , R N ) obtained from the reference rubber bale is equal to the required weight of the selected batch in a proportion corresponding to the predetermined proportion.

7. The method of claim 1 , further comprising the steps of:

providing a weighing station for weighing the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ); and

providing a storage station for holding the pieces (A IJ , B IJ , C IJ ) between successive cycles of batch creation.

8. The method of claim 1 , wherein the transport system comprises:

a feed belt for feeding the cutting station; and

conveyor belts carrying the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ) in order to feed the rubber mixer for batch creation, wherein the conveyor belts comprise at least one scale.

9. The method of claim 8 , further comprising the step of weighing the pieces (A IJ , B IJ , C IJ ) in order to obtain the sum of the weight of the uncured rubber bales (A I , B I , C I ) and the weight of the pieces (A IJ , B IJ , C IJ ).

10. The method of claim 1 , further comprising the step of storing the pieces (A IJ , B IJ , C IJ ) for the next cycle of batch creation, wherein a cumulative weight of the stored pieces is compared to a required weight of a next batch.

11. The method of claim 1 , further comprising programming sequences for the transport system such that a predetermined sequence can be selected from a plurality of sequences.

12. The method of claim 1 , further comprising mixing the selected batch in the rubber mixer.

13. A system for creating unvulcanized rubber batches prior to mixing them in a rubber mixer, including a selection of at least one batch for mixing in the rubber mixer, wherein each batch corresponds to a selection of uncured rubber bales (A I , B I , C I ), that correspond to natures of rubber composition (A, B, C) having predetermined characteristics, the system comprising:

a bale supply station where uncured rubber bales (A I , B I , C I ) are provided from the corresponding natures;

a cutting station that cuts at least one bale (A I , B I , C I ) into pieces (A IJ , B IJ , C IJ );

a weighing station for weighing the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ) removed therefrom;

a transport system that transfers the uncured rubber bales (A I , B I , C I ) and the rubber pieces (A IJ , B IJ , C IJ ) to the rubber mixer and transports the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ) between the supply station, the cutting station and the rubber mixer according to a sequence determined by attaining an equivalence between a sum of a bale weight of the uncured rubber bales (A I , B I , C I ) and a weight of the pieces (A IJ , B IJ , C IJ ) and a required weight of the batch in a proportion corresponding to a predetermined proportion; and

at least one linear actuator that adjusts a position of a reference rubber bale (R) of a predetermined rubber nature and proportion that corresponds to a selected batch at the bale supply station, the provided reference rubber bale (R) having a predefined weight and a predefined length (L) between one end (R L ) and an opposite end (R L′ ), until the opposite end (R L′ ) is brought into contact against a side of a blade (Q) that performs a step of cutting the reference rubber bale (R) at the position (P) of a learning cut.

14. The system of claim 13 , wherein the blade (Q) is provided at the cutting station to perform a step of determining cutting lengths (L C , L C′ , L C″ ) and cutting positions (P, P+1, P+2) of the reference rubber bale (R) to attain a difference between the sum of the weight of the uncured rubber bales (A I , B I , C I ) and the weight of the pieces (A IJ , B IJ , C IJ ) and the required weight of the batch.

15. The system of claim 14 , wherein the system performs the step of determining cutting lengths and cutting positions iteratively until a sum of the weight of the uncured rubber bales (A I , B I , C I ), the weight of the pieces (A IJ , B IJ , C IJ ) and a weight of the pieces (R 1 , R 2 , R 3 , R N ) obtained from the reference rubber bale (R) is equal to the required weight of the batch in a proportion corresponding to the predetermined proportion.

16. The system of claim 13 , wherein the transport system comprises:

a feed belt for feeding the cutting station; and

conveyor belts carrying the uncured rubber bales (A I , B I , C I ) and the pieces (A IJ , B IJ , C IJ ) to the rubber mixer for batch creation, wherein the conveyor belts comprise at least one scale.

17. The system of claim 13 , further comprising the rubber mixer for mixing the batch.

18. An assembly for manufacturing tires comprising the system of claim 13 .