TECHNICAL FIELD

The described invention relates generally to the successive production of rubber compounds in plies. More particularly, the described invention relates to the formation of plies of rubber compound that are stacked in a pallet or in successive pallets.

CONTEXT

Large quantities of individual rubber compounds need to be prepared for the series production of tyres, these individual compounds being prepared in batches. The production of a rubber for a vehicle tyre includes multiple successive mixing steps. For example, Figure 1 shows a mixing system 10 intended for manufacturing one or more rubber products to be incorporated into one or more vehicle tyres. The system 10 includes a mixing installation 20 that carries out a mixing process. The mixing installation 20 includes at least one internal mixer 22 having a chamber 24 with a predefined filling volume. The internal mixer 22 receives an elastomer material 27 (for example, a natural rubber, a synthetic elastomer and combinations and equivalents thereof) and one or more ingredients, with the exception of the vulcanization system. The internal mixer 22 mixes the elastomer material and ingredients in order to obtain a rubber compound 29 therefrom.

The rubber compound 29 is transported to a mixing and cooling installation

30 that includes at least one external mixer having a pair of rollers 32. Following the mixing process realized at the mixing installation 20, the system 10 passes the rubber compound 29 between the rollers 32 in order to form a continuous ply 33. During a process for forming the ply 33, one or both rollers 32 may have a means for cooling by fluid or the like, as is known in the art. This cooling means may be combined with other cooling equipment, for example, at least one spraying installation 40 for controlling a temperature and an addition of water into the produced rubber compound. At the end of a subsequent process (commonly referred to as "batch off), the plies are then deposited in a reciprocating manner (to form a stack, or being "stacked") on a pallet both for transport and for storage before being used in the production of finished products. Being that multiple pallets of plies are filled during tire production processes, an optimized setup of equipment exists that makes it possible to butt the plies together in a pallet and in successive pallets.

SUMMARY

The invention proposes a method for stacking a ply that is transferred from a rubber mixing system to a stacking system. The method includes the step of transferring the ply to a stacking head of the stacking system. The ply is passed to a motorized belt of the stacking system, the motorized belt being able to turn in both directions and being able to move in translation, and the motorized belt being situated between the stacking head and a pallet chosen from a pallet with edges and a pallet without edges. The motorized belt is set into movement in translation so as to move along a path such that the motorized belt receives the ply from the stacking head and makes a downstream end of the ply to be stacked accessible in order to connect it to an upstream end of a ply of a successive pallet and form a butt joint between the plies.

Some methods also include the steps of turning the motorized belt in a first direction; placing the motorized belt in a position to receive the ply from the stacking head at the same time as the stacking head continues to pass the ply to the motorized belt; and stopping the motorized belt from turning at the same time as the stacking head continues to pass the ply.

For some embodiments of the invention, the stacking head has two alternating motorized belts, and each one turns in a predetermined direction at the same time as each one pivots about its axis of rotation along a pre-set contour. For some embodiments of the invention, the alternating motorized belts maintain a spacing between one another in order to pass the ply to the motorized belt.

For some embodiments of the invention, the method also includes the step of pivoting the alternating motorized belts along the pre-set contour in order to stack the ply in the pallet.

Some methods also include the steps of ending stacking when a predetermined quantity of material has been reached in the pallet; turning the motorized belt in an opposite direction; and moving the motorized belt so that it is positioned above the pallet. For some embodiments of the invention, the step of ending stacking also includes the step of taking an upstream end of the ply as far as the top of the pallet.

Some methods also include the step of repeating the stacking for at least one successive pallet chosen from a pallet with edges and a pallet without edges. For some embodiments of the invention, the method also includes the step of creating a junction between a downstream end of the ply and an upstream end of the ply palletized in the successive pallet.

For some embodiments of the invention, the stacking system receives and stacks the material of the ply to a predetermined height or weight of the material.

For some embodiments of the invention, the method also includes the step of choosing a pallet without edges that is capable of descending as a function of a quantity of material received during the stacking of the ply. For some

embodiments, a vertical clearance between the alternating motorized belts and the last fold of the ply remains constant.

The invention also proposes a stacking system that carries out the stacking methods according to the invention.

Further aspects of the described invention will become clearly apparent from reading the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The nature and various advantages of the described invention will become more evident from reading the detailed description that follows, and from studying the attached drawings, in which the same reference numerals denote identical parts throughout, and in which:

FIG. 1 shows a diagram of an exemplary mixing system intended for the production of rubber according to a rubber production method.

FIGS. 2 to 7 show stacking steps carried out by a stacking system according to an embodiment of the invention.

FIG. 8 shows a schematic view of the butting together of the plies stacked by the system in FIGS. 2 to 7. FIGS. 9 to 14 show stacking steps carried out by a stacking system according to another embodiment of the invention.

FIG. 15 shows a schematic view of the butting together of the plies stacked by the system in FIGS. 9 to 14.

DETAILED DESCRIPTION

Referring again to the figures, in which the same numerals identify identical elements, Figures 2 to 15 show embodiments of a method for stacking a ply 50 leaving a rubber mixing system that produces it. A stacking method is carried out by a stacking system 100 that receives the ply 50 from the rubber mixing system. The stacking system 100 can operate with a rubber mixing system such as the system 10 shown in FIG. 1. It will be understood that the stacking system 100 can also operate with other equivalent rubber mixing systems, including additional and complementary systems and installations that carry out other rubber mixing methods. The stacking system 100 can operate with rubber mixing systems that realize single-pass production sequences (i.e., production sequences that are carried out only once before the stacking method) and also with rubber mixing systems that realize multi-pass production sequences (i.e., production sequences that are carried out two or more times before the stacking method). One or more known conveyor belts (or equivalent transport means) transfer(s) the ply 50 from the chosen rubber mixing system to the stacking system 100.

The stacking system 100 includes a material handling device for stacking the ply 50 leaving a rubber mixing system. The handling device has a motorized belt 100 that is able to turn in both directions and a stacking head 120. The motorized belt 1 10 is able to move in translation and is situated between a pallet and the stacking head 120. The pallet is chosen from a pallet P with edges (see FIGS. 2 to 7) and a pallet Q without edges (see FIGS. 9 to 15).

The motorized belt can be set into movement in translation so as to move along a path such that the motorized belt 110 receives the ply 50 from the stacking head 120 and makes a downstream end 50b of the ply 50 to be stacked accessible in order to connect it to an upstream end 52a of a ply 52 of a successive pallet P' (see FIG. 8). The motorized belt 110 takes up a standby position along the path defined while waiting for the pallet P (see FIGS. 3 to 6) or the pallet Q (see FIGS. 10 to 13) to be filled.

The stacking head 120 has two alternating motorized belts 122, and each one pivots about its axis of rotation along a pre-set contour. Each alternating motorized belt 122 can turn in a predetermined direction (for example, see the directions indicated by the arrows A, A' in FIGS. 2 to 7). While the stacking head 120 is operating, the alternating motorized belts 122 maintain a spacing 125 between one another (see FIGS. 6 and 7). The ply 50 is produced with a desired thickness and width, and the spacing 125 can be adjusted in order to pass the ply 50 to the motorized belt 110. The motorized belt 110 and the stacking head 120 can be selected from devices that are commercially available.

Referring again to the figures and to FIG. 2, at the start of stacking, the rubber mixing system transfers the ply 50 to the stacking system 100 and particularly to the stacking head 120 (see the arrow B in FIG. 2). The stacking head 120 receives the ply 50 and, with the alternating motorized belts 122, passes the ply to the motorized belt 110 waiting beneath the stacking head 20. The motorized belt 110 turns in a first direction (see the arrow C) in order to lower an upstream end 50a of the ply 50 on a side P _A outside the pallet P.

Referring to FIG. 3, when the upstream end 50a of the ply 50 is clear of the pallet P, the motorized belt 110 moves back until it is outside the pallet P from the edge P _A (see the arrow D), while continuing to turn in the same direction (see the arrow C). At the same time, the stacking head 120 continues to pass the ply 50 to the motorized belt 110.

Referring to FIG. 4, once the motorized belt 110 has moved clear of the pallet P, the motorized belt takes up the standby position and stops turning. The stacking head 120 continues to pass the ply 50, which descends down to the bottom of the pallet P.

Referring to FIG. 5, when the ply 50 reaches the bottom of the pallet P, the alternating motorized belts 122 pivot along the pre-set contour in order to stack the ply 50 in the pallet P. The stacking head 120 continues to pass the ply 50 in order to start stacking in a "reciprocating" manner from the edge P _A of the pallet P to an opposite edge P _B (i.e., the successive formation of folds and loops). In this embodiment, the palletized material is stacked higher in the pallet P, and the alternating motorized belts 122 remain vertically stationary. It is not necessary to raise the stacking head 120 with respect to the stacking height of the ply. The movement in translation effected by the motorized belt 110, and the vertical clearance of the motorized belt 1 10 with respect to the alternating motorized belts 122, together ensure regular stacking with the regular formation of each loop.

In a final step of the stacking method, stacking ends when a predetermined quantity of material has been reached. Referring to FIG. 6, this stacking is ended by the ply 50 being cut when the pallet P is full. The alternating motorized belts 122 pivot into a neutral position while waiting for the next ply.

Referring to FIG. 7, when the pallet P is full, the motorized belt 110 turns in an opposite direction (see arrow E) with respect to the start of the method. At the same time, the motorized belt 110 moves from the standby position in order to be positioned above the pallet P. Thus, at the end of the stacking method, the motorized belt deposits the upstream end 50a of the ply 50 on the top of the pallet P. In another embodiment, the motorized belt 110 turns in an opposite direction (see the arrow E) but remains in the standby position. In this embodiment, the upstream end 50a of the ply 50 will be deposited along the edge P _A outside the pallet P.

In order to butt the plies 50 and 52 together, stacking can be repeated, as described with respect to FIGS. 2 to 7, in a successive pallet P' . Referring to FIG. 8, in some embodiments, the stacking method includes an optional step of creating a junction J between a downstream end 50b of the ply 50 and the upstream end 52a of the ply 52 palletized in a successive pallet P' . The plies 50 and 52 are thus butted together.

Referring also to FIGS. 9 to 14, another embodiment of a stacking method is realized with a pallet Q without edges. The pallet Q is capable of descending as a function of a quantity of material received during the stacking of the ply 50.

At the start of stacking, the rubber mixing system transfers the ply 50 to the stacking system 100 and particularly to the stacking head 120 (see FIG. 9). The stacking head 120 receives the ply 50 and, with the alternating motorized belts 122, passes the ply to the motorized belt 110 waiting to receive the ply 50. The motorized belt 110 turns in a first direction (see the arrow F) in order to lower a front end 50a of the ply 50 outside the pallet Q. While the stacking head 120 is operating, the alternating motorized belts 122 maintain a spacing 125 between one another (see FIG. 13) that may be adjusted in order to pass the ply 50 to the motorized belt 110.

Referring to FIG. 10, when the upstream end 50a of the ply 50 is clear of the pallet Q, the motorized belt 110 moves back until it is outside the pallet Q (see the arrow G), while continuing to turn in the same direction (see the arrow F). At the same time, the stacking head 120 continues to pass the ply 50 to the motorized belt 110.

Referring to FIG. 11, once the motorized belt 110 has moved clear of the pallet Q, the motorized belt takes up the standby position and stops turning. The stacking head 120 continues to pass the ply 50 that lowers a predetermined length 50c of the ply 50 between the motorized belt 110 and the side QA of the pallet Q that is closest to the motorized belt.

Referring to FIG. 12, the alternating motorized belts 122 pivot along the pre-set contour towards the opposite side QB of the pallet Q. The stacking head 120 continues to pass the ply 50 in order to start stacking in a "reciprocating" manner from the side QA of the pallet Q to the opposite side QB. At the same time as the palletized material is stacked on the pallet Q, the pallet Q descends with respect to the stacking head 20 (see also FIG. 13). A vertical clearance L between the alternating motorized belts 122 and the last fold of the ply 50 remains constant in order to ensure regular stacking with the regular formation of each loop.

In a final step of the stacking method, stacking ends when a predetermined quantity of material has been reached. Referring to FIG. 13, this stacking is ended by the ply 50 being cut when the pallet Q is full. The alternating motorized belts 122 pivot into a neutral position while waiting for a next ply.

Referring to FIG. 14, when the pallet Q is full, the motorized belt 110 turns in an opposite direction (see arrow H) with respect to the start of the method. At the same time, the motorized belt 110 moves so as to be positioned above the pallet Q (see the arrow I). Thus, at the end of the stacking method, the motorized belt deposits the front end 50a of the ply 50 on the top of the pallet Q. The

predetermined length 50c of the ply 50 that has been lowered between the motorized belt 110 and the side QA of the pallet Q is sufficient for the upstream end 50a of the ply 50 to be deposited on the top of the palletized material. In order to butt the plies 50 and 52 together, stacking can be repeated, as described with respect to FIGS. 9 to 14, on a successive pallet Q'. Referring to FIG. 15, in some embodiments, the stacking method includes an optional step of creating a junction J' between a downstream end 50b of the ply 50 and an upstream end 52a of the ply 52 palletized in a successive pallet Q' (see FIG. 15). The plies 50 and 52 are thus butted together.

The butt joint thus obtained makes it possible to use a long length of ply (several pallets) in a downstream method without the intervention of an operator. Increases in productivity are thus realized.

For the two embodiments, it will be understood that the stacking system

100 is capable of receiving and stacking the material of a ply up to a predetermined height or weight. Consequently, the stacking system 100 can also have an automated detection system that includes at least one sensor for the increasing height of the loops. The detection system effects detection and generates one or more signals indicating the height. The detection system may include a means for detecting the weight of the material and of the pallet, wherein the signals are emitted when a predetermined weight is reached.

The stacking system 100 may also include a monitoring system that is configured to receive the detected signals (for example, the height or weight signals) and to emit one or more proportional control signals. Monitoring may be continuous or intermittent, such that the control signals effect an adjustment in real time of the material stacking parameters (for example, by modifying the rate at which the stacking head 120 stacks the ply 50 in the pallet P or on the pallet Q). The monitoring system may be programmed to stop the stacking of the ply when a fault is detected in the stacking system 100. It is thus easy to verify the proper operation of the stacking system 100 and to make adjustments if necessary.

The monitoring system may include at least one programmable controller communicating with the stacking system 100. The programmable controller may have, programmed within it, data established for a plurality of plies of rubber compound that each have different stacking method parameters. With the aid of these data, the monitoring system may be configured to receive the signals detected and make a corresponding adjustment. All or part of the monitoring system may be remote-controlled by way of a network. The ranges given as lying "between a and b" encompass the values of "a" and "b".

Although particular embodiments of the disclosed device have been illustrated and described, it will be appreciated that various changes, additions and modifications can be made without departing from either the spirit or scope of the present description. Therefore, no limitation should be imposed on the scope of the invention described, except for the limitations set out in the appended claims.