TECHNICAL DOMAIN

The invention relates to a slitting device and a cross-cutting process for performing a cross-cut of a moving semi-finished product.

BACKGROUND

In the field of tires, there are various performance requirements for the tire (e.g., reduced rolling resistance, improved wear resistance, comparable grip in wet and dry conditions, sufficient mileage, etc.). Tire manufacturing therefore includes the production of semi-finished products in a continuous sheet (as used here, the terms "product" and "semi finished product" are used interchangeably). The sheet is made up of reinforced rubber plies including different rubber mixtures that are calendered with filament or strip reinforcements embedded therein. The nature of the filament and the nature of the rubber are chosen according to the desired final characteristics. As used herein, the term "filament" includes, without limitation, metallic (such as steel wire, film or cable), synthetic or textile reinforcing elements (or "reinforcements").

As represented in the prior art, blades or knives are known for cross-cutting semi finished products, including wide (e.g., 1000mm to 1600mm) and particularly reinforced (e.g., incorporating reinforcements in the form of warp filaments) calendered products. For example, publication CN202625460 discloses a machine incorporating a tension winding device connected to a slitting device for cutting wide semi-finished products. Further, publication KR20080114308 discloses an apparatus for cutting a wide semi-finished product incorporating straight cutting blades instead of circular knives for the purpose of reducing the price of the blades as well as their replacement.

Referring to Figure 1, the prior art also provides blades 10 that are spaced apart to obtain strips and/or bands at a desired width. The blades 10 being arranged in a so-called "floating" assembly are not fixed with respect to a support 12. This type of assembly allows a transverse oscillation of the blades 10 with respect to the moving semi-finished product S (see arrow A in figure 1) (see publication FR2795998). In this configuration, an elevated temperature is sometimes produced at the contact point P between each blade 10 and the semi-finished product S in movement. Thus, the blades 10 may undergo rapid wear that requires blade replacement. Given the relatively hard nature of the materials of the incoming semi-finished product and the high working speeds (for example, the installation of the blades or knives allowing to continuously split a wide semi-finished product entering at a speed of 200 m/min in order to separate it into strips), it is possible to increase the life of the blades. The use of harder materials (or by using hardening treatments) on the blades generates a consequent additional cost to the realization of the blades. Also, the reduction of the working speed leads to a loss of productivity of a machine that makes the necessary cuts. In addition, if a blade support device allows it, an adjustment of the blade height can move the contact point between the blade and the semi-finished product while moving, requiring a stop for intervention without solving the problem of heating of the blade at the contact point.

In order to continuously change the point of contact between the blades and a moving semi-finished product, the disclosed invention allows the positioning of one or more blades along an oscillating curve so as to limit the heating of the blades at a given point. The cutting quality of these blades ensures an optimal geometry of the obtained strips, especially at the edges.

SUMMARY OF THE INVENTION

The invention is directed to a slitting device for performing a cross-cut of a moving semi-finished product, characterized in that the device includes:

- a frame retractably mounted with respect to a pair of substantially parallel, floor- fixed guides, the frame being set in motion by an eccentric rotation system that moves the frame along a predefined distance of the guides;

- a housing fixedly mounted to the frame;

- a plurality of slitting blocks mounted in an oscillating manner in the housing and consecutively aligned so as to span substantially the entire width of the semi-finished product, each slitting block including:

- a body of predetermined length coextensive with an actuating extension disposed proximate an actuating means and an opposite free extension; and

- a blade removably mounted adjacent the free extension of the corresponding body, each blade being a generally linear member having a predetermined length and being positioned perpendicular to the path of the semi-finished product; wherein the slitting blocks are arranged along a common axis allowing oscillation in pairs of slitting blocks. In some embodiments of the device, each blade is mounted in an inclined manner relative to the body. In such embodiments, each blade is mounted at an angle of about 30° to 60°.

In some embodiments of the device, the blades are disposed below the path of the semi-finished product.

In some embodiments of the device, the eccentric rotation system includes a motor or motors that perform a reciprocating movement of a piston to perform a corresponding movement of a connecting rod that causes a rotational movement of a corresponding cam.

The invention also relates to a tire manufacturing installation including the disclosed device.

The invention also relates to a cross-cutting process for obtaining strips from a semi finished product or products in an installation of the invention, the process including the following steps:

- a step of moving, at a predetermined speed, at least one semi-finished product along a path to the device;

- a step of setting the frame in oscillating motion, during which the eccentric rotation system moves the frame between a standby position, where the axis of the slitting blocks remains perpendicular to the axis X-X, and a cutting position, where points of contact between the blades and the semi-finished product follow a path in the form of a corresponding curve; and

- a step of resuming the standby position before the arrival of the semi-finished product.

In some embodiments of the process, the step of setting the frame in oscillating motion is done automatically and continuously during the process.

In some embodiments of the process, the process further includes an end-of-line step.

Other aspects of the invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The nature and various advantages of the invention will become more apparent from the following detailed description, in conjunction with the accompanying drawings, in which the same reference numerals designate identical parts throughout, and in which:

Figure 1 represents a schematic view of a slitting device of the prior art.

Figure 2 represents a side view of a slitting device of the invention. Figure 3 represents a front view of the slitting device of Figure 2.

Figure 4 represents a schematic view of the slitting device of the invention during a cross-cutting process.

DETAILED DESCRIPTION

Referring now to the figures, in which the same numbers identify the same elements, an embodiment of a slitting device (or "device") 100 is shown in Figures 2 and 3. An embodiment of a process for cross-cutting a moving semi-finished product S, performed by the device 100, is shown in Figure 4. The device 100 may be included in a tire manufacturing installation having several workstations. The production of tires can therefore be realized by an automated and continuous process or processes in which the cutting and eventual bonding of the cut semi-finished products is performed over a minimum cycle time.

The calendered materials processed by the device 100 may include reinforced rubber plies. Examples of suitable filaments include, but are not limited to, side-by-side textile reinforcements. Each filament may be any individual reinforcement having a cross-sectional dimension (either predefined diameter or predefined thickness). The selected filaments may have any suitable cross-sectional geometry

A rubber ply used in calendered materials includes a conventional rubber-based composition for calendering sheets, and its thickness can be tailored to the product in which it will be placed (for example, in a belt). The rubber ply may be made from a diene elastomer, i.e., any elastomer derived at least in part from diene monomer. This diene elastomer may be selected from polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), butadiene copolymers, isoprene copolymers and mixtures of these elastomers, such copolymers being selected from butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR), and isoprene butadiene-styrene copolymers (SBIR). A rubber composition selected for the rubber ply may contain one or more diene elastomers as well as one or more additives commonly used in rubber matrices for tire manufacture. Such fillers include, but are not limited to, carbon black, silica, coupling agents, anti-aging agents, antioxidants, plasticizers, extender oils, plasticizing resins having a high glass transition temperature (above 30°C), agents for improving the processability of the compositions in the raw state, tackifying resins, anti -reversion agents, methylene acceptors and donors, reinforcing resins, known adhesion promoter systems of the metal salt type and a cross-linking or vulcanization system. The person skilled in the art knows how to adjust the formulation of the rubber composition in order to obtain the desired properties for a specific tire.

Referring again to FIGS. 2 and 3, the device 100 includes a frame 106 that is retractably mounted relative to a pair of substantially parallel slides 104 that are fixed to the ground. The frame 106 is set in motion by a known eccentric rotation system 108 that moves the frame along a predefined distance of the slides 104. In one embodiment of the eccentric rotation system 108, a motor or motors (not shown) perform reciprocating movement of a piston to effect corresponding movement of a connecting rod that causes rotational movement of a corresponding cam. It is understood that the eccentric rotation system 108 may be replaced by equivalent means (e.g., actuator(s) and linear guide means) to set the frame 106 in motion.

Referring again to Figures 2 and 3, and further to Figure 4, the device 100 further includes a housing 110 that is fixedly mounted to the frame 106 of the device. It is understood that the housing 110 remains removable from the frame 106 to allow for maintenance and/or replacement. A plurality of slitting blocks 112x (where X varies from 1 to N depending on the semi-finished product being processed) (see Figure 4) are mounted in an oscillating manner in the housing 110. The slitting blocks 112 are consecutively arranged along a common axis X-X allowing oscillation in pairs of slitting blocks. The slitting blocks 112 are consecutively aligned and arranged to cover substantially the entire width of the semi finished product. In some embodiments, an optional guide may be provided, which ensures alignment of the slitting blocks 112 in a standby position prior to engagement with a moving semi-finished product. Each slitting block 112 includes a body 112a of predetermined length coextensive with an actuating extension 112a' disposed proximate an actuating means (not shown) and an opposite free extension 112a". Each slitting block 112 also includes a blade 112b removably mounted proximate the free extension 112a" of the corresponding body 112a. The slitting blocks 112 are arranged such that the blades 112b are aligned. Thus, the movement of the frame 106 performs a so-called "floating" movement of the blades 112b with respect to the path of the semi-finished product. By providing a plurality of blades 112b aligned at a constant pitch, the cut of the semi-finished product is applied between filaments across the entire semi-finished product.

Each blade 112b is a generally linear element having a predetermined length based on the selected semi-finished product and its corresponding profile. As depicted in Figures 2 and 4, each blade 112b may be mounted at an angle to the body 112a (for example, at an angle of approximately 30° to 60°). The selected angle may be varied depending on the properties of the semi-finished product. In one embodiment, the device 100 further includes a roller marker (not shown) that supports the semi-finished product during a cross-cutting process performed by the device.

The blades 112b are positioned perpendicular to the path of the semi-finished product S' (see Figure 4). Spaces may be provided between each pair of blades 112b, or between intermittent pairs, to optimize the distribution of the cut along the selected semi-finished product profile. This configuration ensures that the cut made of a semi-finished product is a cross-sectional cut between filaments.

As shown in Figure 4, the blades 112b are disposed below the semi-finished product S'. It is understood that the housing 110 can be mounted so that the slitting blocks 112 (and thus the blades 112b) are disposed above the moving semi-finished product depending on its speed and/or positioning.

Referring again to FIGS. 2 through 4, a detailed description is given as an example of a cross-cutting process (or "process") of the invention performed by an installation incorporating the device 100. It is understood that the process can be readily adapted for any embodiment of the device 100.

In initiating a cross-cutting process of the invention, the process includes a step of feeding, at a predetermined speed, a semi-finished product S' along a path to the device 100 (see arrow B in Figure 4). The semi-finished product S' is selected from a profile or profiles that are manufactured at one or more installations upstream of the device 100. The linear movement of the semi-finished product S' and its speed can be managed based on its profile and its proximity to the device 100 (detected, for example, by a proximity sensor or equivalent device).

The cross-cutting process also includes a step of setting the frame 106 in oscillating motion (i.e., vertical reciprocation) to attain a corresponding oscillating motion of the slitting blocks 112, and thus the blades 112b, relative to each other (see arrow C in Figure 4). During this step, the eccentric rotation system 108 moves the frame 106 between a standby position (where the axis of the slitting blocks 112 remains perpendicular to the X-X axis) (see Figure 3) and a cutting position (where contact points P' between the blades 112b and the semi finished product S' follow a path in the form of a corresponding curve) (see Figure 4).

The height of the oscillation may be attained, for example, by selecting the appropriate eccentric rotation system 108 and in relation to the size of the blades 112b. The frequency of oscillation may be variable in order to adapt it to the speed of travel of the semi-finished product S'. Given the oscillating mounting of the frame 106 with respect to the guides 104, the blades 112b follow a path in the form of a corresponding curve that can be modified according to the properties of the semi-finished product. The path followed by the blades 112b thus avoids cutting the filaments of the semi-finished product.

During this step, an oscillating or reciprocating movement (that is, a vertical coming- and-going) of the frame 106 is performed automatically and continuously during the process. This movement changes the point of contact P' of the blades 112b with respect to the path of the semi-finished product S' (see Figure 4). This configuration limits the heating of the blades 112b at a given point, thus extending their life. It becomes possible to process harder materials at higher speeds to achieve industrial productivity.

During this step, the movement of the blades 112b can be selected from predetermined positions. The relative movement of adjacent pairs of blades 112b may be performed or controlled as a whole, in sections or individually relative to each other, by means of one or more actuators. Both the amount of contact points P' and the quality of cut between the blades 112b and the semi-finished product S' ensure production uniformity for all cross- sectional profiles.

The cross-sectional cutting process further includes a final step of resuming the standby position before the arrival of a subsequent semi-finished product. In embodiments of the process, the process may restart from this step to perform at least one step of the process in an iterative manner until a desired number of strips is obtained from the semi-finished products.

In embodiments of the cross-cutting process, the process further includes an optional end-of-line step. In some embodiments of the process, this step includes a step of packaging or coiling the obtained strips. In some embodiments of the process, this step may further include at least one step of storing the obtained strips.

The device 100 of the invention adapts to varying thicknesses of the semi-finished products. Changes in the thickness of the semi-finished product are dimensionally specific and therefore induce financial and time costs. The device 100 of the invention allows rapid production of strips for multiple tire types without major capital investment. It is understood that the slitting block 112 may allow for a different mounting of the blades 112b depending on the thickness of the semi-finished product being processed. For example, one or more blades 112b may be provided in a kit having a corresponding slitting block 112. For such a kit, one or more blades 112b may be interchangeable in a slitting block 112 selected according to the profile of the semi-finished product.

A cross-cutting process performed by the device 100 may be controlled by PLC and may include pre-programming of management information. For example, a process setting may be defined using the properties of the calendered materials of the semi-finished product S'. A process setting may also be defined using the precise configuration of the frame 106 and the blades 112b with respect to a selected semi-finished product.

It is understood that the blades can incorporate one or more temperature devices that permits a change to the blade position. By using temperature devices (for example, temperature probes of the type PT100 or of the thermocouple type), the heating of the blades can be known at any time. If the temperature reaches a defined threshold, a corresponding automatism will act on the eccentric rotation system 108 to change the position of the product cutting point on the blades. This will allow the previous cutting point to go down in temperature and thus increase its life.

For all embodiments, a monitoring system could be implemented. At least a portion of the monitoring system may be provided in a wearable device such as a mobile network device, e.g., a cell phone, a laptop computer, a network-connected wearable device(s) (including "augmented reality" and/or "virtual reality" devices, network-connected wearables and/or any combinations and/or equivalents).

In some embodiments of the invention, the device 100 (or an installation incorporating the device 100) may receive voice commands or other audio data representing, for example, the current state of the current process relative to the expected state. The response may be generated in audible, visual, tactile (e.g., using a haptic interface) and/or virtual and/or augmented form.

Some cross-cutting processes may include a step or steps of training the device 100 (or training an installation incorporating the device 100) to recognize representative characteristics of the semi-finished products in movement (e.g., filament diameter values), for comparison with target values. This step may include a step of training the device 100 (or an installation incorporating the device 100) to recognize non-equivalences between the compared values. Each training step includes a classification generated by self-learning means. This classification may include, without limitation, the material parameters of the filaments used, the parameters of the produced strips, the durations of the cross-cutting cycles, and the expected values at the end of a current cycle (for example, the number of strips obtained at the end of the cycle). It is conceivable that detection and comparison steps can be performed iteratively. In embodiments of the cross-cutting process of the invention, the obtained data may supply a neural network(s) that manages the device 100 and/or an installation(s) in which the device 100 is incorporated.

The device 100 of the invention is suitable for processing a variety of calendered materials for use in a variety of semi-finished products without decreasing industrial productivity.

The terms "at least one" and "one or more" are used interchangeably. Ranges that are presented as being "between a and b" include both "a" and "b" values.

Although particular embodiments of the disclosed apparatus have been illustrated and described, it will be understood that various changes, additions, and modifications may be practiced without departing from the spirit and scope of this disclosure. Accordingly, no limitations should be imposed on the scope of the described invention except those set forth in the appended claims.