EP1385398A1

EP1385398A1 - Antiskid material with improved friction factor, tyre and shoe sole incorporating same

Info

Publication number: EP1385398A1
Application number: EP02727703A
Authority: EP
Inventors: Pascal Tournier
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-27
Filing date: 2002-04-26
Publication date: 2004-02-04
Also published as: FR2824068B1; WO2002087376A1; FR2824068A1

Abstract

The invention concerns an antiskid material comprising an elastomer matrix (1) and having at least a contact surface (1a), characterised in that said matrix (1) incorporates flexible fibres (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011, 211) inclined relative to said contact surface (1a), said fibres being made of a material having a rigidity higher than that of said matrix (1), said fibres being supported or maintained, directly or indirectly, in said matrix (1) by means of at least one element forming a support (12, 23, 32, 72, 82, 92, 102, 103, 111, 113, 122, 123, 133, 143, 152, 162, 2013, 212), and at least one end of said fibres is flush with or slightly overlaps said contact surface (1a) such that said fibres improve the friction factor of said material. The invention is applicable to tyres, shoe soles, antiskid mats, transmission belts, rollers or driving rollers, goods handling gloves.

Description

Non-slip material with improved grip, pneumatic and shoe sole incorporating such a material.

The invention relates to the field of non-slip materials. More specifically, the invention relates to the structure of a non-slip material making it possible to increase the adhesion coefficient, the material obtained being intended for use in applications such as in particular tires, shoe soles, non-slip mats , transmission belts, rollers or drive rollers, handling gloves, brake pads, etc. In this area, several qualities and / or functions must be fulfilled by non-slip materials, and in particular:

- present a satisfactory adhesion with various surfaces likely to present variable states (dry, wet, icy ...); - dissipate little energy when requested;

- present a flexibility allowing them to accept the irregularities of the surfaces with which they are brought into contact;

- not to be noisy when requested;

- offer good resistance to wear. Conventionally, such materials are made in whole or in part of elastomeric materials which allow significant tangential forces to be transmitted while exhibiting attractive elasticity qualities.

However, although the elastomers offer a high coefficient of friction combined with hyperelasticity, the use of a single elastomer does not make it possible to meet all of the qualities and / or functions listed above. Soft erasers, for example, offer better adhesion but wear out quickly, unlike hard erasers.

A given elastomer is in particular characterized by its viscoelastic properties, the friction of the elastomers being governed inter alia by molecular adhesion and the viscoelastic losses of the material. However, the higher the viscoelastic losses, the greater the energy capable of being dissipated by the material.

These viscoelastic losses are reflected in particular by:

- an increase in rolling resistance in the case of tires;

- performance deterioration in the case of machines using belts or drive rollers;

- an increase in user fatigue in the case of shoe soles. A compromise is therefore most often sought between adhesion and energy dissipation generated by a non-slip material.

More particularly, in their application to tires, non-slip materials conventionally incorporate treads or crampons. In this case, the tire coating is most often striated to increase the contact pressure on wet ground. However, such streaks decrease the grip of the tire on a dry surface.

Studded tires are also known for use on snowy or icy ground. In this context, nails have been proposed made of an elastomeric material reinforced with short fibers. These tires are intended for a particular use, it is necessary to change tires when the road conditions are changed. Indeed, such nails rather cause a loss of grip on dry or wet ground, this undesirable effect being amplified during braking, the elastomeric nails may tend to bend favorably to sliding rather than opposing it.

Tires with a tread reinforced with short fibers are also known. These tend to follow the profile of the sculpture during molding. They are therefore mainly in a situation substantially parallel with respect to the contact surface and are easily removed. Reinforced tire pads are also known on the leading and trailing edges. These fibers or reinforcements are integrated into the tire in such a way that they cannot oppose strong constraints, just like the treads comprising rigid particles arranged randomly. There are also known pads comprising fibers arranged substantially perpendicularly to the contact surface. These fibers flex when they are stressed without tending to become embedded in the relief of the contact surface. This vertical arrangement of the fibers allows an increase in rigidity but not in adhesion. The invention aims to overcome the drawbacks of the prior art.

More specifically, the invention aims to provide an anti-slip material which has a higher coefficient of adhesion than that of the solutions of the prior art while inducing low energy dissipation when it is used. Another object of the invention is to provide such a material which has sufficient flexibility to become embedded in the irregularities of the surface with which it is in contact.

The invention also aims to provide such a material which offers good resistance to wear. The invention also aims to provide such a material which can be integrated into the tread of a tire in order to improve its grip while reducing the rolling resistance compared to known tires.

Another objective of the invention is to provide such a tire provided with a non-slip material which contributes to improving the braking of the vehicle, and therefore to reducing stopping distances, including when cornering.

The invention also aims to provide such a tire incorporating a non-slip material which contributes to the functioning, or at least to the improvement of the functioning of safety systems or members which equip the vehicle. The invention also aims to provide such a material which can be integrated into shoe soles contributing to the comfort of the user.

These objectives, as well as others which will appear subsequently, are achieved thanks to the invention which relates to a non-slip material comprising an elastomeric matrix and having at least one contact surface.

According to the invention, said matrix incorporates fibers inclined with respect to said contact surface, said fibers being made of a material having a rigidity greater than that of said matrix, said fibers being supported or maintained, directly or indirectly, in said matrix using at least one support member, and at least one end of said fibers is flush with or slightly protrudes from said contact surface, so that said fibers improve the adhesion of said material.

Unlike the prior art, the adhesion of the non-slip material according to the invention is improved appreciably without causing an increase in the dissipation of energy or excessive wear of the material, and this under various conditions of use.

In fact, when stresses oppose the fibers, their extremity flush or slightly protruding from the contact surface tends to become embedded in the relief of the surface with which the material is in contact, while entraining the surrounding elastomer of the matrix. This has the effect of increasing the actual contact surface.

It is noted that the fibers entrain the surrounding elastomer of the matrix because they are embedded in the matrix by adhering to it. This result is obtained insofar as the fibers extend over most of the thickness of the matrix, being directly or indirectly integral with it.

This joining will be direct in the case for example where the fibers are overmolded by the matrix. It will be indirect if the fibers are brought into the recesses of the matrix, then glued or overmolded therein, the glue or the overmolding elastomer then ensuring adhesion between the fibers and the matrix.

A wedge effect in the relief cavities of the contact surface is also obtained. It is also noted that the support element according to the invention is a separate element from the elastomeric matrix, and molded by it. It is indeed essential that this support element is distinct from the matrix, by being more rigid than the latter, to form a limit to the displacement of the fibers and, consequently, to the deformation of the matrix on its side opposite to the surface. of contact. Thus, the fibers and the matrix support higher tangential stresses than in the prior techniques, the adhesion of the non-slip material being therefore increased.

There is no increase in energy dissipation, on the contrary, because the increase in adhesion is allowed thanks to mechanical work of the fibers.

In addition, the encrustation of the fibers in the surface with which the material is in contact is favored by the inclination of the fibers allowing them to bend when they are subjected to compressive and / or shear stresses. The fibers can thus brace themselves and offer a high resistance to sliding.

To do this, the fibers are flexible and therefore do not behave like nails such as those integrating studded tires, in order for example not to degrade the road surface, in the case where the material is applied to a tire. If the materials are made of a relatively rigid material such as a metal, the diameter of the fibers will be chosen so as to guarantee their flexibility.

It will be noted that if the fibers protrude too far from the surface, the adhesion would be reduced, because the emerging parts of these fibers would act as a flocking of fibers. Thus, unlike certain flocking techniques according to which the fibers are inserted into a matrix only over a small part of their length, while most of their length is external to the matrix, the fibers according to the invention only 'outcrop or, at most, protrude from the matrix only over a small part of their length, for example not exceeding 5 to 15% of their total length. It is therefore understood that most of the length of the fibers is embedded in the matrix. Ideally, the fibers are only flush with the contact surface of the matrix, that is to say that they are completely embedded in it, in order to improve the service life of the material by limiting the stresses exerted on the fibers during low stresses (such as those occurring during normal rolling, in the case where the material is applied to a tire).

Using the fibers arranged in a non-slip material according to the invention, the matrix can be made of a relatively stiff elastomeric material while allowing better adhesion and less wear than with the flexible elastomeric materials of the prior art.

According to a preferred solution, said fibers form an angle α of between approximately 5 ° and approximately 70 ° with the normal to said contact surface. Preferably, said fibers form an angle α of between approximately 25 ° and approximately 50 ° with the normal to said contact surface.

The inclination of the fibers will be adapted according to the direction of the stresses for which better adhesion is sought. In the other directions, the lower adhesion makes it possible to further reduce the energy dissipation of the non-slip material. The fibers are arranged in an organized, that is to say non-random, otherwise the effect of increasing the adhesion could not be obtained. In fact, according to a random arrangement, the increase in adhesion obtained using fibers oriented in the same direction would be compensated by a loss of adhesion due to an orientation of other fibers in an opposite direction. It is therefore preferable to favor a direction for the inclination of the fibers. According to a first advantageous solution, said support element comprises at least one ply embedded in said matrix, one end of said fibers coming to bear on said ply.

It will be noted that the embedded ply forming the support is relatively inflexible.

In this way, the fibers can oppose fairly high stresses since they are retained by one of their ends in the matrix. This prevents the fibers from undergoing an overall displacement with the flexible matrix. In addition, such a characteristic contributes to better encrustation of the fibers in the surface with which the non-slip material is in contact, and therefore to better adhesion.

According to a second advantageous solution, said at least one support member cooperates with said fibers to hold them. Advantageously, in one or the other solution, the said means or means forming a support have, at least in the zone where they cooperate with said fibers, a blister admitting of being deformed.

In this case, said blister consists of a gas pocket.

In this way, the fibers are supported or maintained on a support element which is itself flexible while having a limited displacement, which allows the fibers to better match the strong possible roughness of the surface with which the non-slip material is in contact.

According to another embodiment of the maintenance of the fibers by the support element, said fibers overlap or intertwine said one or said support means.

Weft threads, possibly present in the matrix of the material to reinforce it, can then advantageously be used as elements forming a support for the fibers.

According to another embodiment of the maintenance of the fibers by the support element, one end of said fibers is embedded in said means support. In this case, said fibers preferably comprise at least one zone of greater flexibility near said end embedded in said support means.

In this way, the fibers can be deformed without exerting excessive torque at their embedded end, thus limiting the risk of loosening of the fibers.

Preferably, said fibers comprise means for limiting their movement around said zone of greater flexibility.

Alternatively, said fibers have at least one branch. In this case, said at least one branch forms at least one annular or spiral element surrounding at least one of said fibers.

Such ramifications limit the deformations of the fibers, which has the effect of reducing the risk of cohesion between the fibers and the matrix.

In addition, the fibers thus formed further entrain the matrix with them, forcing the material to conform to the shape of the surface with which it is in contact.

These ramifications are capable of providing a suction effect while distributing the stresses between the fibers and the matrix.

According to another variant, the non-slip material comprises complementary means for maintaining said fibers in an intermediate position between said sheet or said support means and said contact surface.

Such means help to limit the deformation of the fibers.

According to another embodiment, said fibers have different inclinations with respect to said contact surface so that several of said fibers converge with each other at said contact surface.

Such a configuration proves to be particularly advantageous for an application of the invention to tires. In fact, in this case, the fibers may react to stresses occurring both longitudinally and laterally, for example in the case of braking when cornering. According to a variant, said fibers have different inclinations with respect to said contact surface so that several of said fibers diverge from each other at said contact surface.

According to a first embodiment of the fibers, said fibers each comprise at least one long unitary fiber.

According to a second embodiment of the fibers, said fibers are made of an agglomerate of particles and entangled fibers.

According to another embodiment of the fibers, said fibers comprise fibrils or aligned particles integrated in a plastic or elastomeric material.

Such fibers can be produced by molding or by extrusion and then cutting, before their integration into the non-slip layer.

Advantageously, said fibers are made of one or more materials belonging to the following group: - vulcanized or thermoplastic elastomer,

- plastic,

- aluminum,

- steel,

- glass, - carbon,

- aramid,

- animal hair.

In the case where rigid materials are chosen, such as steel and aluminum, this material will preferably be associated with at least one second material (the two materials can be in the form of filaments) which will have the function of avoiding rigid material to deform permanently.

According to another characteristic, said fibers are sensitive to a magnetic or electric field. According to an advantageous solution common to the previous embodiments, at least one of said fibers is connected to information transmission means.

The invention also relates to a method of manufacturing an anti-slip material as described above, comprising the steps consisting in:

- injecting said matrix into a mold provided with inserts intended to provide passages for said fibers by overmolding said at least one support element;

- Introducing said fibers into said passages once the inserts have been removed;

- overmolding or fixing said matrix, said at least one support element and said fibers.

According to another embodiment, a method of manufacturing an anti-slip material as described above comprises the steps consisting in:

- Place said fibers in a mold and keep them in position through said mold and / or at least one support member;

- overmolding said fibers and said at least one support element by said matrix.

According to yet another embodiment, a method of manufacturing an anti-slip material as described above comprises the steps consisting in:

- injecting a mixture comprising said matrix and said fibers or the compounds of said fibers into a mold;

- Apply a variable electric or magnetic field in the mold in an orientation corresponding to the desired inclination of said fibers; - Vibrating said mold before or during at least a fraction of the application of said electric or magnetic field.

To ensure better cohesion between the fibers and the matrix, the fibers, the particles, or the fibrils that make up the fibers, may be subjected to an additional treatment such as sizing, irradiation, flame treatment, spraying with a chemical agent. or soaking in a chemical bath (phosphorus, sulfur, chromium, oxygenation bath, hydrogenation bath).

According to another method making it possible to obtain the inclination of the fibers in the matrix, a radial and perpendicular field is applied then a shearing of the elastomer is caused. It is obtained by rotating only one of the peripheral parts of the mold, the outer or inner one. The particles are subjected to the field which encourages them to have a radial alignment. The part of the rotating mold frictionally drives the surrounding matrix and, by the viscosity effect, the fibrils formed are deflected by this shearing. Thus the fibrils instead of being radial, form spirals, all the more inclined as the induced shear is high.

The invention also relates to a tire comprising an anti-slip material comprising an elastomeric matrix and having at least one contact surface with a ground, said matrix integrating flexible fibers inclined relative to said contact surface, said fibers being made of a material having a rigidity greater than that of said matrix, said fibers being supported or maintained, directly or indirectly, in said matrix by means of at least one support element, and in that at least one end of said fibers is flush or slightly protrudes from said contact surface.

Such a tire makes it possible to obtain a significant drop in rolling resistance and therefore to cause lower energy consumption. The grip of the tire being improved, the stopping distances of a vehicle which is equipped with it are reduced and the road handling is notably improved.

According to an advantageous embodiment of such a tire, said information transmission means are connected to one or more of the following systems:

- anti-lock braking system during braking;

- wheel traction control system;

- system for detecting the pressure and / or the inflation state of said tire;

- wear detection system of said tire.

Better precision is thus obtained for the implementation of ABS (Anti Blocking System) systems, by taking the information directly from the tire tread. The invention also relates to a shoe sole comprising a non-slip material comprising an elastomeric matrix and having at least one contact surface with a ground, said matrix integrating flexible fibers inclined relative to said contact surface, said fibers being made of a material having a rigidity greater than that of said matrix, said fibers being in support or maintained, directly or indirectly, in said matrix by means of at least one support element, and in that at least one end of said fibers is flush with or slightly protrudes from said contact surface.

The orientation of the fibers in the studs can vary depending on their location on the sole to cope with different stresses.

According to an advantageous embodiment of such a shoe sole, said information transmission means are connected to a system for detecting the coefficient of adhesion or friction of said sole on said ground. Preferably, said system for detecting the coefficient of adhesion or friction is coupled to at least one sound and or light emitter activated when said coefficient of adhesion or friction detected has a value below a predetermined threshold. Other characteristics and advantages of the invention will appear more clearly on reading the following description of several preferred embodiments of the invention given by way of illustrative and nonlimiting examples, and of the drawings among which:

- Figure 1 shows a sectional view of a non-slip material according to the invention;

- Figure 2 illustrates in section a tread of a tire incorporating a non-slip material according to the invention;

- Figure 3 shows a variant of a tire tread incorporating a non-slip material according to the invention; - Figure 4 illustrates an embodiment of the non-slip material according to the invention, in which the fibers are sensitive to an electric field;

- Figure 5 illustrates another embodiment of the non-slip material according to the invention, in which the fibers consist of particles sensitive to a magnetic field;

- Figure 6 illustrates an embodiment of the fibers according to which they consist of an elastomeric or thermoplastic bead incorporating fibrils;

- Figure 7 shows an embodiment of the fixing of the fibers according to which they are embedded in a support;

- Figure 8 shows another embodiment of the fixing of the fibers in which the fibers integrate a joint;

- Figure 9 shows another method of fixing by embedding the fibers in a support; - Figures 10 to 12 each illustrate an embodiment for fixing the fibers, the latter overlapping on a support;

- Figures 13 and 14 each show a variant of the embodiment of the fixing by embedding the fibers on a support; - Figure 15 illustrates another method of fixing the fibers on a support using an intermediate piece;

- Figure 16 illustrates yet another embodiment of the fibers on a support having a blister;

- Figure 17 shows an embodiment of the fibers according to which they have ramifications;

- Figure 18 shows another embodiment of the fibers having ramifications;

- Figure 19 illustrates an embodiment of the inclination of the fibers according to which they diverge at the level of the contact surface of the non-slip material according to the invention;

- Figure 20 shows a shoe sole incorporating a non-slip material according to the invention;

- Figure 21 illustrates a step in a manufacturing process allowing the alignment of fibers sensitive to a magnetic field. Referring to Figure 1, an anti-slip material according to the invention comprises an elastomeric matrix 1 having a contact surface la.

According to the invention, fibers 11 are embedded in the matrix 1 while being inclined relative to the contact surface la by forming an angle of approximately 45 ° with a normal to the contact surface la. According to this embodiment, by one of their ends, the fibers 11 are supported on a support 12, itself embedded in the matrix 1, the other end of the fibers coming flush with the contact surface 1a.

Such a non-slip material is placed under or on a structure 2, which varies according to the application envisaged. Each fiber here consists of a flexible elastomeric cord having a rigidity greater than that of the matrix 1, this cord forming a long unitary fiber.

The elastomer material constituting the bead is loaded with rigid particles and has a modulus of elasticity 1.5 times greater than that of the matrix

1.

In other embodiments, the fibers may be made of steel, plastic (polyamide, polypropylene, polycarbonate, polyester, polyvinyl, polyacrylic, etc.), iron, aluminum, glass, carbon, aramid, in animal hair or in several of these materials.

The support 12 is a sheet made of a material such as a metal (steel, iron, aluminum, copper), a thermoplastic (polyamide, polypropylene, polyethylene, polycarbonate, phenylene polysulfide, polyester, thermoplastic elastomer), rayon, glass, aramid, carbon. Thus, as illustrated in FIG. 6, the fibers 61 are produced by molding or by extrusion of an elastomer reinforced by short fibers 611 substantially aligned in the direction of the fiber 61.

According to another embodiment of the invention as illustrated in FIG. 7, the fibers 71 are embedded in the support 72 which thus keeps them in the matrix 1. An alternative consists in making the fibers 71 at the same time as the support 72 by molding. The fibers 71 could, according to another production method, be welded or glued to the support 72.

It will be noted that the fibers 71 have at their base a flexible zone 711, obtained by a narrowing of section, allowing them to deform without exerting excessive torque at the level of the embedding, thus limiting the risk of loosening.

FIG. 8 shows another embodiment of the embedding of the fibers 81 in the support 82, according to which the fibers 82 integrate, near the support, a joint formed by two arms 811. This articulation further comprises a stop 812 which limits the recoil of the fiber 81 beyond a deformation threshold.

FIG. 9 illustrates yet another embodiment of the embedding of the fibers 91 in the support 92, according to which the fibers 91 have a head 911 integrating a peripheral groove 912 intended to cooperate with the support 92 which has an oblong opening , to form a built-in connection.

In this embodiment, it is noted that the fiber 91 comprises a zone of greater flexibility 913 (shrinking of the fiber) and that the matrix 1 covers only the elongated part of the fiber 91.

Two other embodiments of the embedding of the fibers are illustrated by FIGS. 13 and 14, according to which the fibers 131, 141 are coupled to a connecting element 132, 142 comprising a flexible part 1311, 1411, embedded in the element support 133, 143. With reference to FIG. 13, the fiber 131 is tubular and contains a tackifying (sticky) elastomer having a rebound coefficient of less than 30, helping to further strengthen the adhesion of the non-slip material according to the invention.

It will be noted that the heels 1321, 1421 form a stop capable of limiting the pivoting of the connecting elements 132, 142 relative to the supports

133, 143.

FIG. 15 illustrates another embodiment of the attachment of the fibers 151 to the support element 152, according to which the fibers are secured to a part 153 held in the support 152. The part 153 is preferably obtained by overmolding of the base fibers, by a thermoplastic material (PP, PE,

PA ...), and possibly a thermosetting resin (polyester, epoxy, polyurethane).

Other forms of holding the fibers in the matrix 1 are illustrated in FIGS. 10 to 12. As illustrated in FIG. 11, the matrix 1 integrates weft yarns 111 around which the fibers 112 are folded, thus overlapping the yarns 111.

As clearly appears in FIG. 10, a variant consists in interlacing the fibers 101 with the weft threads 102.

In another variant represented by FIG. 12, the fibers 121 overlap an intermediate fabric 122.

It will be noted for these last three embodiments, that the movement of the fibers in the matrix is limited by the presence of an element forming a stop 103, 113, 123 against which the fibers are capable of coming to bear. The spacing between the fibers 101, 112 or 121 and the element 103, 113 or 123 is less than 20% of the thickness of the matrix 1 and preferably less than 10% of this thickness.

In another embodiment illustrated in FIG. 16, the fibers 161 are held by a reinforcement 162 having a blister 1621 capable of deforming under the thrust of the fibers. This blister 1621 is obtained by the introduction of a chemical agent releasing a gas beyond a certain temperature during the molding of the matrix 1, forming a gas pocket 1622.

Recesses 163 are also provided in the matrix 1 to improve the mobility of the fibers 161 within the matrix.

According to the embodiments which have just been described, the fibers incorporating an anti-slip material according to the invention are essentially elongated.

They can also have ramifications, as illustrated by FIGS. 17 and 18.

Referring to Figure 17, the fibers 171 have branches 1711 comprising annular terminations 1712 (in section in Figure 17). These branches 1711 and terminations 1712 are preferably obtained by molding of thermoplastic material. It is noted, according to the embodiment illustrated in FIG. 18, that the fibers 181 having branches 1811 are bordered by elongate fibers 182 intended to limit the deformation of the matrix and to improve the resistance to wear, in particular in the case of a crampon as shown. The fibers 182 aligned in the transverse direction on the leading and trailing edges of the crampon, are optionally held transversely by weft threads, and in this case make up a fabric supported on the support 183.

In common with all of the embodiments which have just been described, the method of manufacturing the material according to the invention consists of a pre-molding of the matrix, the mold being provided with an insert intended to provide passages in the matrix for subsequent introduction of the fibers produced separately by molding or extrusion.

Once the inserts have been removed, the fibers are placed in the mold and secured to the elastomer using overmolding, followed by baking. According to an alternative, the fibers are placed and maintained in the mold, possibly by means of their attachment to their support, then overmolded by the matrix.

According to another embodiment, the fibers are sensitive to an electric or magnetic field in order to impose an inclination on them once they are embedded in the matrix of the non-slip material according to the invention.

Thus, with reference to FIG. 5, the fibers 51 comprise fibrils or particles 511 sensitive to a magnetic field (or electric according to another embodiment) mixed with an elastomer.

The inclination of the fibers is obtained by applying a variable magnetic field in the mold as illustrated in FIG. 21.

With reference to this FIG. 21, the matrix 1 and the particles 2111 sensitive to a magnetic field intended to form the fibers 211 are injected into a mold comprising an inner wall 2131 and an outer wall 2132, a support element 212 having been previously disposed in the mold. The magnetic circuit 2141, made up of sheets and connected to the coil 214, makes it possible to produce a magnetic field oriented in the direction of the arrow F2 in the air gap (space between the endings 2142 and 2143), the direction of the magnetic field being obtained by setting up, in the desired direction, terminations 2142, 2143 of the magnetic circuit 2141 on the internal walls of the walls 2131 and 2132 respectively of the mold.

The walls of the mold outside the magnetic field are made up or coated with a non-magnetizable material so as not to deflect the applied magnetic field and limit magnetic leaks. The variations of the magnetic field correspond to an application by successive and progressive stages of the electric intensity which traverses the coil 214, aiming to optimize the operation together with a vibration of the mold using a piezoelectric element 215 ( simply closing the mold may constitute sufficient shaking or vibration). According to the embodiment illustrated in Figure 4, the fibers 41 are made of plastic and coated with an ionizable layer, before being injected with the matrix material in a mold.

The inclination of the fibers is obtained according to a process similar to that used for the embodiment described above. It will be noted that the fibers may have different inclinations. Indeed, as it appears in FIG. 19, the fibers 191 and 192 are inclined differently with respect to the contact surface la so that they diverge at the level of the surface la. Fibers do this in two directions. According to another embodiment, the fibers 191 and 192 could converge at the contact surface la to increase their transverse stability.

The application of a non-slip material according to the invention to tires will now be described with the aid of the example in FIG. 2. As shown in FIG. 2, a tire comprises a pneumatic chamber 26, a carcass reinforcement 27, a layer of elastomer 28, a tread comprising sculptures or spikes 21, in particular intended for driving water off on wet roads . The studs have a contact surface with the ground 20.

According to the invention, the tread and the studs of the tire comprise an elastomer matrix 1 in which fibers 22 are embedded, inclined at approximately 45 ° relative to the surface in contact with the ground 20.

The fibers 22 come to bear on a sheet 23 embedded in the matrix 1, an intermediate element 24 contributing in a complementary manner to the maintenance of the fibers 22 in their inclined position. For better support, the fibers 22, composed of long mixed glass - polypropylene fibers, are welded by heating to the element 24, consisting of a fabric comprising polypropylene fibers. In the event of vehicle braking, tending to exert forces oriented in the direction of the arrow FI indicated in FIG. 2, the fibers, by their orientation, tend to brace, their ends at the contact surface tending to become embedded in the relief of the ground 20, while their other end is held by the ply 23. According to a variant illustrated in FIG. 3, the fibers 31 are fixed on a support 32 which approximately follows the profile of the spikes . It is interesting to draw the fibers 31 from the support 32 made of a fabric.

According to an advanced embodiment of a tire incorporating a non-slip material according to the invention, fibers 22 are connected to information transmission means.

The information transmission means comprise a sensor 25 placed between the fibers 21 and the ply 23. The signal from the sensor 25 is transmitted by an electrical contact between the wheel shaft and the chassis of the vehicle to a processing device. information integrated into an operating system of information related to the brake control in order to avoid locking of the wheels during braking.

The sensor 25 consists of a piezoelectric film which generates an electric current as a function of the stress of the fiber which presses on it. According to other versions, the sensor 25 can also be of the capacitive, resistive or even inductive type.

As illustrated in FIG. 14, the sensor 144 is of the resistive type, then consisting of a strain gauge fixed on the flexible zone 1411 of the connecting element 142 of the fibers 141 with the support element 143. The fibers are in this case preferably connected in series with each other by an electrical connection, forming a network through which an electric current is sent. The measurement of the electrical impedance fluctuations makes it possible to identify the variation in electrical resistance of the network or networks thus formed, giving an indication of the behavior of the fibers. According to another embodiment of the sensors, the fibers can be made of optical fibers serving both as transmitter and receiver. As pulses are sent to the optical fibers, the reflected signal differs according to the contact or absence of contact of the fiber with the ground. Analysis of the received signal then makes it possible to deduce the state of stress of the fibers, which acts in particular on the distortion of the signal. The level of grip and the speed of rotation are thus determined.

According to yet another embodiment of the sensors, fibers comprising magnetic particles have a portion, preferably their base, arranged through a winding of electrically conductive wire. The relative displacement of the magnetized particles through the turns of this winding, depending on the stresses on the fiber, generates an electric current. This signal representing the response of a set of inductive sensors of this type is used to determine the speed of rotation (or displacement) and the level of grip.

According to yet another type of sensor, conductive fibers distributed around the periphery are connected in series. An electric current is generated at through this network. Each passage of a conductive fiber on the ground causes a drop in current by transmitting part of it to the ground. Fluctuations in the response recorded determine the speed of rotation.

Whatever the embodiment of the sensor or sensors which cooperate or which are at least partly made up of said fibers, the processing of the information can also make it possible to detect the state of an under-inflated tire, the slackening of the tire resulting in a demand for a greater number of fibers than normal.

The application of a non-slip material according to the invention to the soles of shoes will now be described with the aid of FIG. 20.

As it clearly appears in this figure, the sole 200 includes sculptures 201 integrating inclined fibers 2011, embedded in a matrix 1, and coming to bear on a support element 2013.

According to an advanced embodiment of such a sole, at least one of the fibers 2011 is connected to at least one means of transmitting information.

The information means are linked to a system for detecting the adhesion coefficient. To do this, a sensor 2012 sensitive to variations in fiber deformation is connected to an electronic circuit which processes the signal from the sensor so as to deduce a loss of adhesion. The technique used for the sensor is chosen from one of the techniques mentioned above for applying the non-slip material according to the invention to tires.

A sound or light signal is generated when the detected coefficient of adhesion has a value below a predetermined threshold. The non-slip material according to the invention can also be used in other applications in an advantageous manner, in particular by being integrated into products such as non-slip mats, transmission belts, rollers or drive rollers, gloves for handling ....

The application of the invention to the belts makes it possible to transmit a greater torque without increasing the dissipation of energy. However the The contact surface of the sheaves must be striated or bumpy, in order to provide anchor points for said fibers. The V-belts are produced by stacking successive layers in accordance with the invention. To prevent said fiber support member from moving away from one side of the surface under the pressure of said fibers, the fibers are arranged symmetrically with respect to the radiant plane of symmetry of the sheave and they work in the same direction on each layer to have no deviation from the support. This is not the case with current belts reinforced with fabrics where the transverse fibers have one end drawn and the other repelled, which has the effect of making the fibers enter rather than making them come out according to the invention.

It should also be noted that the fibers according to the invention can advantageously be installed only on the front part of a brake shoe.

The sensors according to the invention can also be used in other applications such as the movement control of a roller, a drive roller or a belt installed on a machine. Another application relates to the detection of the passage of a person on a carpet. This type of sensor informs a door opening and closing control device or even triggers an alarm.

Other embodiments using the principle of a non-slip material integrating a matrix in which are embedded fibers inclined relative to a contact surface as described above are of course conceivable without departing from the scope of the invention.

Claims

- Non-slip material comprising an elastomeric matrix (1) and having at least one contact surface (la), characterized in that said matrix (1) incorporates flexible fibers (11, 22,

31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011, 211) inclined relative to said contact surface (la), said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011 , 211) being made of a material having a rigidity greater than that of said matrix (1), said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 191, 192, 2011, 211) being supported or maintained, directly or indirectly, in said matrix (1) using at least one support element (12, 23 , 32, 72, 82, 92, 102, 103, 111, 113, 122, 123, 133, 143, 152, 162, 2013, 212) and in that at least one end of said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011, 211) is flush with or slightly protrudes from said surface of contact (la), so that said fibers improve ent the adhesion of said material. - Non-slip material according to claim 1, characterized in that said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181 , 182, 191, 192, 2011, 211) form an angle α of between approximately 5 ° and approximately 70 ° with the normal to said contact surface. - Non-slip material according to claim 2, characterized in that said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181 , 182, 191, 192, 2011, 211) form an angle α of between approximately 25 ° and approximately 50 ° with the normal to said contact surface. - Non-slip material according to any one of claims 1 to 3, characterized in that said support member (12, 23, 32, 152, 162, 2013, 212) comprises at least one ply embedded in said matrix, one end of said fibers (11, 22, 31, 151, 161, 2011, 211) bearing on said sheet. - Non-slip material according to any one of claims 1 to 3, characterized in that said at least one support element (12, 32, 102, 111, 122) cooperates with said fibers (11) to maintain them. - Non-slip material according to claims 1 to 5, characterized in that the said support means (162) have, at least in the zone where they cooperate with said fibers (161), a blister (1621) admitting to deforming. - Non-slip material according to claim 6, characterized in that said blister (1621) consists of a gas pocket (1622). - Non-slip material according to claim 5, characterized in that said fibers (101, 112, 121) overlap or intertwine said one or more support means (102, 111, 122). - Non-slip material according to claims 5 or 6, characterized in that one end of said fibers (71, 81, 1) is embedded in said support means (72, 82, 92). - Non-slip material according to any one of claims 5 to 9, characterized in that said fibers (71, 81, 91, 131, 141) comprise at least one zone of greater flexibility (711, 811, 913, 1311, 1411 ) near said end embedded in said support means. - Non-slip material according to claim 10, characterized in that said fibers (81, 131, 141) comprise means for limiting (812, 1321, 1421) their movement around said area of greater flexibility. - Non-slip material according to any one of claims 1 to 11, characterized in that said fibers (171, 181) have at least one branch (1711, 1811). - Non-slip material according to claim 12, characterized in that said at least one branch (1711) forms at least one annular or spiral element (1712) surrounding at least one of said fibers (1711). - Non-slip material according to any one of claims 1 to 13, characterized in that it comprises complementary means for holding (24) said fibers at an intermediate position between said ply or said support means (23) and said surface. contact. - Non-slip material according to any one of claims 1 to 14, characterized in that said fibers (191, 192) have different inclinations relative to said contact surface so that several of said fibers converge with each other at said level contact surface. - Non-slip material according to any one of claims 1 to 14, characterized in that said fibers (191, 192) have different inclinations relative to said contact surface so that several of said fibers diverge between them at said level contact surface. - Non-slip material according to any one of claims 1 to 16, characterized in that said fibers (11, 22, 31, 41, 71, 81, 91, 101, 112, 121, 141, 151, 161, 171, 181 , 182, 191, 192, 2011) each comprise at least one long unitary fiber. - Non-slip material according to any one of claims 1 to 16, characterized in that said fibers (61) are made of an agglomerate of particles and entangled fibers (611). - Non-slip material according to any one of claims 1 to 16, characterized in that said fibers (51) comprise fibrils or aligned particles (511) embedded in a plastic or elastomeric material. - Non-slip material according to any one of claims 1 to 19, characterized in that said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151 , 161, 171, 181, 182, 191, 192, 2011, 211) are made of one or more materials belonging to the following group

- vulcanized or thermoplastic elastomer,

- plastic, - aluminum,

- steel,

- glass,

- carbon,

- aramid, - animal hair. - Non-slip material according to claim 20, characterized in that said fibers (41, 51, 211) are sensitive to a magnetic or electric field. - Non-slip material according to any one of claims 1 to 21, characterized in that at least one of said fibers (11, 22, 31, 41, 51, 61,

71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011, 211) is linked to information transmission means (25, 144, 2012 ). - Method for manufacturing an anti-slip material according to any one of claims 1 to 22, characterized in that it comprises the steps consisting in:

- injecting said matrix (1) into a mold provided with inserts intended to provide passages for said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141 , 151, 161, 171, 181, 182, 191, 192, 2011) by overmolding said at least a support member (12, 23, 32, 72, 82, 92, 102, 103, 111, 113, 122, 123, 133, 143, 152, 162, 2013, 212);

- introduce said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011) in said passages once the inserts removed;

- overmolding or fixing said matrix (1), said at least one support element (12, 23, 32, 72, 82, 92, 102, 103, 111, 113, 122, 123, 133, 143, 152, 162, 2013, 212) and said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011). - Method for manufacturing an anti-slip material according to any one of claims 1 to 22, characterized in that it comprises the steps consisting in:

- place said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91, 101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011) in a mold and hold them in position by means of said mold and / or at least one support element (12,

23, 24, 32, 72, 82, 92, 102, 103, 111, 113, 122, 123, 133, 143, 152, 162, 2013, 212); - overmolding said fibers (11, 22, 31, 41, 51, 61, 71, 81, 91,

101, 112, 121, 131, 141, 151, 161, 171, 181, 182, 191, 192, 2011) and said at least one support element (12, 23,

24, 32, 72, 82, 92, 102, 103, 111, 113, 122, 123, 133, 143, 152, 162, 2013, 212) by said matrix (1). - Method for manufacturing an anti-slip material according to any one of claims 1 to 22, characterized in that it comprises the steps consisting in:

- injecting a mixture comprising said matrix (1) and said fibers (211) or the compounds of said fibers (211) into a mold; - Apply a variable electric or magnetic field in the mold in an orientation corresponding to the desired inclination of said fibers;

- Vibrating said mold (2131, 2132) before or during at least a fraction of the application of said electric or magnetic field. - Tire characterized in that it comprises a non-slip material comprising an elastomeric matrix (1) and having at least one contact surface with a ground (20), said matrix (1) integrating flexible fibers (22) inclined relative to said contact surface, said fibers (22) being made of a material having a rigidity greater than that of said matrix (1), said fibers (22) being supported or maintained, directly or indirectly, in said matrix (1) at using at least one support element (23), and in that at least one end of said fibers (22) is flush with or slightly protrudes from said contact surface according to any one of claims 1 to 22. - Tire according to claims 22 and 26, characterized in that said information transmission means (25) are connected to one or more of the following systems: - anti-lock braking system during braking;

- wheel traction control system;

- system for detecting the pressure and / or the inflation state of said tire;

- wear detection system of said tire. - Shoe sole characterized in that it comprises a non-slip material comprising an elastomer matrix (1) and having at least one contact surface with a ground, said matrix (1) integrating flexible fibers (2011) inclined relative to said contact surface, said fibers (2011) being made of a material having a rigidity greater than that of said matrix (1), said fibers being in support or maintained, directly or indirectly, in said matrix using at least one support element (2013), and in that at least one end of said fibers (2011) is slightly flush with or protrudes from said contact surface according to any one of claims 1 to 22. - Shoe sole according to claims 22 and 28, characterized in that said information transmission means (2012) are connected to a system for detecting the coefficient of adhesion or friction of said sole on said ground. - Shoe sole according to claim 29, characterized in that said system for detecting the adhesion or friction coefficient is coupled to at least one sound and / or light transmitter activated when said detected coefficient of adhesion or friction has a value below a predetermined threshold.