TIRE COMPRISING A KNITTED FABRIC AND REINFORCING ELEMENTS

Abstract

A reinforcing assembly for a tire includes a knit and a plurality of reinforcing elements. The knit includes a right side and a wrong side. The reinforcing elements extend parallel to one another and each criss-cross the knit over at least a portion of the knit. The knit is arranged in such a way that the right side is positioned radially outside relative to the wrong side.

Claims

1-28. (canceled)

29. A tire comprising a reinforcing assembly, wherein the reinforcing assembly includes: a knit having a right side and a wrong side; and a plurality of reinforcing elements that extend parallel to one another, wherein each of the reinforcing elements criss-cross the knit over at least a portion of the knit, and wherein the knit is arranged such that the right side of the knit is positioned radially outside relative to the wrong side of the knit.

30. The tire according to claim 29, wherein the knit includes: a plurality of columns of loops, with loops of a same column being arranged one after another substantially overall in a main direction (X1) of the knit, and a plurality of rows of loops, with loops of a same row being arranged one beside another substantially overall in a transverse direction (Z1) of the knit, and wherein each of the reinforcing element extends substantially overall in the main direction or in the transverse direction.

31. The tire according to claim 29, wherein each of the reinforcing elements is a filamentary element that includes at least one multifilament strand formed of a plurality of elementary monofilaments, and wherein each of the elementary monofilaments is made from a metallic material, or a textile material, or both a metallic material and a textile material.

32. The tire according to claim 30, wherein each of the reinforcing elements is a filamentary element that includes at least one multifilament strand formed of a plurality of elementary monofilaments, and wherein each of the elementary monofilaments is made from a metallic material, or a textile material, or both a metallic material and a textile material.

33. The tire according to claim 29, wherein each of the reinforcing elements is a filamentary element formed of a metallic monofilament.

34. The tire according to claim 30, wherein each of the reinforcing elements is a filamentary element formed of a metallic monofilament.

35. The tire according to claim 29, further comprising: a crown; a tread surmounting the crown; two sidewalls; two beads; a carcass reinforcement; and a crown reinforcement, wherein the two sidewalls connect the two beads to the crown, respectively, wherein the carcass reinforcement is anchored in each of the beads and extends through the sidewalls towards the crown, wherein the crown reinforcement is radially interposed between the carcass reinforcement and the tread, and wherein the reinforcing assembly is included in the crown reinforcement.

36. The tire according to claim 35, wherein the crown reinforcement includes a working reinforcement that includes a plurality of working plies.

37. The tire according to claim 36, wherein each of the working plies includes working reinforcing elements that form an angle in a range of from 15 to 40 with a circumferential direction of the tire.

38. The tire according to claim 37, wherein the working reinforcing elements are crossed from one of the working plies to another of the working plies.

39. The tire according to claim 37, wherein at least one of the working plies includes the reinforcing assembly, with the reinforcing elements of the reinforcing assembly forming the working reinforcing elements of the at least one of the working plies.

40. The tire according to claim 39, wherein the reinforcing assembly is one of a plurality of reinforcing assemblies of the tire, and wherein each of the working plies includes a corresponding one of the reinforcing assemblies, with the reinforcing elements of each of the reinforcing assemblies forming the working reinforcing elements of a corresponding one of the working plies.

41. The tire according to claim 35, wherein the crown reinforcement includes: a working reinforcement that includes a plurality of working plies, and a protective reinforcement that includes a protective ply.

42. The tire according to claim 41, wherein each of the working plies includes working reinforcing elements that form an angle in a range of from 15 to 40 with a circumferential direction of the tire, and wherein the protective ply includes protective reinforcing elements that form an angle in a range of from 5 to 35 with the circumferential direction of the tire.

43. The tire according to claim 42, wherein the working reinforcing elements are crossed from one of the working plies to another of the working plies.

44. The tire according to claim 42, wherein the protective ply includes the reinforcing assembly, with the reinforcing elements of the reinforcing assembly forming the protective reinforcing elements of the protective ply.

45. The tire according to claim 42, wherein at least one of the working plies includes the reinforcing assembly, with the reinforcing elements of the reinforcing assembly forming the working reinforcing elements of the at least one of the working plies.

46. The tire according to claim 45, wherein the reinforcing assembly is one of a plurality of reinforcing assemblies in the tire, and wherein each of the working plies includes a corresponding one of the reinforcing assemblies, the reinforcing elements of each of the reinforcing assemblies forming the working reinforcing elements of a corresponding one of the working plies.

47. The tire according to claim 41, wherein the protective ply is interposed radially between two of the working plies.

48. The tire according to claim 41, wherein the protective ply is interposed radially between the tread and the working reinforcement.

49. A method of reinforcing a tire, the method comprising incorporating a reinforcing assembly in the tire, the reinforcing assembly including: a knit having a right side and a wrong side; and a plurality of reinforcing elements that extend parallel to one another, wherein each of the reinforcing elements criss-cross the knit over at least a portion of the knit, and wherein the knit is arranged such that the right side of the knit is positioned radially outside relative to the wrong side of the knit.

50. A method of manufacturing a tire, the method comprising: obtaining a reinforcing assembly that includes: a knit having a right side and a wrong side, and a plurality of reinforcing elements that extend parallel to one another, wherein each of the reinforcing elements criss-cross the knit over at least a portion of the knit, and wherein the knit is arranged such that the right side of the knit is positioned radially outside relative to the wrong side of the knit; and embedding the reinforcing assembly in a matrix of at least one elastomer.

Description

[0073] The invention will be better understood in the light of the following description which is given merely by way of indication and which is not intended to restrict the said invention, accompanied by the figures below:

[0074] FIG. 1 is a view in cross section of a tire according to a first embodiment of the invention comprising an assembly;

[0075] FIG. 2 is a schematic view of the details of an assembly according to a first embodiment of the invention comprising a weft knit and reinforcing elements which criss-cross in phase with the inter-loop elements of the knit;

[0076] FIG. 3 is a schematic depiction of an assembly according to a second embodiment of the invention comprising a weft knit and reinforcing elements which criss-cross in phase-opposition with the inter-loop elements of the knit;

[0077] FIG. 4 is a schematic depiction of an assembly according to a third embodiment of the invention comprising a warp knit and reinforcing elements which criss-cross in phase with the inter-loop elements of the knit;

[0078] FIG. 5 is a schematic depiction of an assembly according to a fourth embodiment of the invention comprising a warp knit and reinforcing elements which criss-cross in phase-opposition with the inter-loop elements of the knit;

[0079] FIG. 6 is a photograph of a right side of an assembly according to a fifth embodiment of the invention;

[0080] FIG. 7 is a photograph of a wrong side of the assembly of FIG. 6; and

[0081] FIGS. 8 and 9 are views similar to that of FIG. 1 of tires respectively according to second and third embodiments.

[0082] In the various figures, analogous elements are denoted by identical references. Furthermore, in order to present a view that makes the invention easier to understand, the various elements are not necessarily drawn to scale.

[0083] In the following description, when the term radial is used, it is appropriate to make a distinction between several different uses of the word by a person skilled in the art.

[0084] Firstly, the expression refers to a radius of the tire. It is in that sense that a point A is said to be radially inside a point B (or radially on the inside of the point B) if it is closer to the axis of rotation of the tire than is the point B. Conversely, a point C is said to be radially outside a point D (or radially on the outside of the point D) if it is further from the axis of rotation of the tire than is the point D. Progress radially inwards (or outwards) will mean progress towards smaller (or larger) radii.

[0085] It is this sense of the word that applies also when radial distances are being discussed.

[0086] On the other hand, a reinforcing element or a reinforcement is said to be radial when the reinforcing element or the reinforcing elements of the reinforcement make an angle greater than or equal to 65 and less than or equal to 90 with the circumferential direction.

[0087] An axial direction is a direction parallel to the axis of rotation of the tire. A point E is said to be axially inside a point F (or axially on the inside of the point F) if it is closer to the median plane of the tire than is the point F. Conversely, a point G is said to be axially outside a point H (or axially on the outside of the point H) if it is further from the median plane of the tire than is the point H.

[0088] The median plane M of the tire is the plane which is normal to the axis of rotation of the tire and which is situated equidistantly from the annular reinforcing structures of each bead.

[0089] A circumferential direction is a direction which is perpendicular both to a radius of the tire and to the axial direction.

[0090] Furthermore, any range of values denoted by the expression between a and b represents the range of values extending from more than a to less than b (in other words excluding the limits a and b), whereas any range of values denoted by the expression from a to b means the range of values extending from the limit a as far as the limit b, in other words including the strict limits a and b.

DETAILED DESCRIPTION OF EXAMPLES OF TIRES ACCORDING TO THE INVENTION

[0091] A frame of reference X, Y, Z corresponding to the usual respectively axial (X), radial (Y) and circumferential (Z) directions of a tire has been depicted in the figures.

[0092] FIG. 1 depicts a tire according to the invention and denoted by the general reference 10. The tire 10 is substantially of revolution about the axis X. The tire 10 here is intended for industrial vehicles, for example vans, heavy vehicles such as heavy-duty vehiclesi.e. underground trains, buses, road haulage vehicles (lorries, tractors, trailers), off-road vehicles, agricultural vehicles or civil engineering plant, aircraft, other transport or handling vehicles.

[0093] The tire 10 comprises a crown 12 comprising a crown reinforcement 14 comprising a working reinforcement 15 comprising two working plies 16, 18 of reinforcing elements and a protective reinforcement 17 comprising a protective ply 19. The crown reinforcement 14 is surmounted by a tread 20. Here, the protective reinforcement 17, here the protective ply 19, is interposed radially between the working reinforcement 15 and the tread 20.

[0094] Two sidewalls 22 extend the crown 12 radially inwards. The tire 10 further comprises two beads 24 radially on the inside of the sidewalls 22 and each comprising an annular reinforcing structure 26, in this instance a bead wire 28, surmounted by a mass of filling rubber 30, and also a radial carcass reinforcement 32. The carcass reinforcement 32 is surmounted radially by the crown reinforcement 14.

[0095] The carcass reinforcement 32 preferably comprises a single carcass ply 34 of radial textile reinforcing elements, the ply 34 being anchored in each of the beads 24 by being turned up around the bead wire 28 so as to form within each bead 24 a main strand 38 extending from the beads 24 through the sidewalls 22 to the crown 12 and a turnup 40, the radially outer end 42 of the turnup 40 here being substantially midway up the height of the tire.

[0096] The carcass reinforcement 32 thus extends from the beads 24 through the sidewalls 22 to the crown 12. As an alternative, the radial reinforcing elements of the carcass reinforcement 32 are metallic.

[0097] The working plies 16, 18 comprise metal or textile reinforcing elements forming an angle of from 15 to 40, preferably ranging from 20 to 30 and here equal to 26 with the circumferential direction of the tire. The working reinforcing elements, in this instance made of metal, are crossed from one working ply to the other.

[0098] The protective ply 19 comprises metallic or textile protective reinforcing elements, in this instance metallic ones, that form an angle ranging from 5 to 35, preferably ranging from 10 to 30, with the circumferential direction of the tire.

[0099] Each working ply 16, 18, protective ply 19 and carcass ply 34 comprises an elastomer matrix in which the reinforcing elements of the corresponding ply are embedded. An elastomer (or rubber, the two terms being synonymous) matrix means a matrix comprising at least one elastomer. The compositions of the elastomer matrices of the working plies 16, 18, protective ply 19 and carcass ply 34 are conventional compositions for the calendering of reinforcing elements conventionally comprising a diene elastomer, for example natural rubber, a reinforcing filler, for example carbon black and/or silica, a crosslinking system, for example a vulcanizing system, preferably containing sulphur, stearic acid and zinc oxide, and possibly a vulcanization accelerant and/or retarder and/or various additives.

[0100] With reference to FIGS. 2 to 7, the crown reinforcement 14 comprises an assembly 44 described hereinbelow. Here, the protective ply comprises, by way of reinforcing element, the assembly 44 comprising a knit 46 and a plurality of reinforcing elements 48. The reinforcing elements 48 extend parallel to one another and each criss-cross the knit 46 over at least a portion of the knit 46. The reinforcing elements 48 of the assembly form the protective reinforcing elements of the protective ply 19.

[0101] Thus, such an assembly is more resistant to puncturing by virtue of the crossovers between the knit and the reinforcing elements. Specifically, the knit makes it possible to limit the separation between the reinforcing elements, and vice versa.

[0102] For preference, the knit 46 is made up of one or more filamentary elements of a material selected from a polyester, a polyamide, a polyketone, a polyvinyl alcohol, a cellulose, a mineral fibre, a natural fibre, an elastomeric material or a mixture of these materials.

[0103] Furthermore, each reinforcing element 48 is advantageously a filamentary element comprising at least one multifilament strand comprising several elementary monofilaments and in which each elementary monofilament is made from a metallic material and/or a textile material.

[0104] As depicted in FIGS. 2 to 5, the or each knit 46 comprises columns C1, C2, C3, C4 (Ci) of loops B and rows R1, R2, R3, R4 (Rj) of loops B. The loops B of one and the same column Ci are arranged one after another substantially in an overall direction referred to as the main direction X1. The loops B of one and the same row Rj are arranged one beside the other substantially in an overall direction referred to as the transverse direction Z1. A loop of a column Ci and of a row Rj is denoted Bi,j in the remainder of the description.

[0105] The main X1 and transverse Z1 directions of each knit 44 make, with respect to one another, an angle of between 75 and 105, preferably between 85 and 95. Here, the main X1 and transverse Z1 directions are substantially perpendicular to one another.

[0106] The transverse overall direction Z1 makes an angle at most equal to 10 with the circumferential direction Z of the tire 10 and in this instance an angle equal to 0, the transverse overall direction Z1 of each knit 46 being substantially parallel to the circumferential direction Z of the tire. The main overall direction X1 of the knit 46 is substantially parallel to the radial direction X of the tire.

[0107] Advantageously, each reinforcing element 48 extends substantially in the main overall direction X1 or the transverse overall direction Z1.

[0108] For preference, each reinforcing element 48 extends substantially in the main overall direction X1, as illustrated in FIGS. 2 to 7. In that case, this assembly is also referred to as a column-filled knit, namely a knit which contains elements filled in over the entire length of the workpiece and held in place by the stitches of the basic construction.

[0109] Advantageously, each reinforcing element 48 criss-crosses with loops B of one and the same column Ci and/or with inter-loop elements E of two distinct columns of loops, in this instance consecutive columns C.sub.i, and C.sub.i+1. An inter-loop element E.sub.i,j is defined as being the portion of a filamentary element of the knit connecting two loops belonging to two distinct columns i, j of loops, in this instance consecutive columns of loops.

[0110] In the case of a weft knit, this is the portion of filamentary element connecting two loops B.sub.i,j, B.sub.i+1,j of the same row R.sub.j belonging to two consecutive columns C.sub.i, C.sub.i+1.

[0111] In the case of a warp knit, this is the portion of filamentary element connecting two loops B.sub.i,j, B.sub.i,j belonging to two columns and to two rows that are distinct (ii and jj). For preference, i=i+1 and j=j+1, which means to say that the two rows and the two columns are consecutive.

[0112] For preference, the assembly 44 comprises a plurality of reinforcing elements 48 arranged in such a way that a reinforcing element 48 criss-crosses with at least one loop B in each column every f column and/or with at least one inter-loop element E of each pair of consecutive columns of loops every f pairs of consecutive columns of loops, as illustrated in FIGS. 2 to 7.

[0113] For preference, f=1, which means to say that the assembly 44 comprises a plurality of reinforcing elements 48 arranged in such a way that each reinforcing element 48 criss-crosses with a loop B in each column and/or with an inter-loop element of each pair of consecutive columns of loops.

[0114] For preference, each reinforcing element 48 criss-crosses with each loop B of one and the same column and/or with each inter-loop element E of two consecutive columns of loops.

[0115] Having a comparable number of reinforcing elements and of columns of knit makes it possible to achieve a maximum density of reinforcing elements and a well-controlled separation between the reinforcing elements.

[0116] For preference, each reinforcing element 48 criss-crosses with the knit 46 on each row of the knit 46. Of course, each reinforcing element may criss-cross with the knit at regular intervals with the rows of the knit, this recurrence being chosen in such a way as to achieve predetermined mechanical properties for the assembly.

[0117] Advantageously, the reinforcing elements 48 criss-cross in phase with the loops of a row R of the knit and/or with the inter-loop elements of loops of a row R of the knit. As illustrated in FIGS. 2, 4, 6 and 7, the reinforcing elements 48 criss-cross in phase with all the inter-loop elements of loops of one and the same row R of the knit. Thus, with reference to these figures, considering the reinforcing elements 48-1, 48-2 and 48-3, these criss-cross in the same way with all loops B.sub.i,j of one and the same row R.sub.j and/or with all the inter-loop elements E.sub.i,j of loops of one and the same row R.sub.j. According to the definition given hereinabove, the reinforcing elements 48-1, 48-2 and 48-3 criss-cross on the same side of the knit with each inter-loop element E.sub.i,j of one and the same row R.sub.j.

[0118] In an alternative form, the reinforcing element 48 criss-cross in phase-opposition with the loops of one and the same row R and/or with the inter-loop elements of loops of one and the same row R. As illustrated in FIGS. 3 and 5, considering two consecutive reinforcing elements 48-1 and 48-2, these do not criss-cross in the same way with two consecutive loops B.sub.i,j and/or with two consecutive inter-loop elements E.sub.i,j of the same row R.sub.j. According to the definition given hereinabove, the reinforcing elements 48-1 and 48-2 criss-cross on opposite sides of the knit with each inter-loop element E.sub.i,j of one and the same row R.sub.j.

[0119] For preference, the or each knit 44 is a warp knit as illustrated in FIGS. 4 to 7. Nevertheless, weft knits are also conceivable, as illustrated in FIGS. 2 and 3. Any type of construction is possible for each knit 44.

[0120] Each knit 44 is produced using a knitting method conventional to those skilled in the art in this field.

[0121] Furthermore, the knit has a right side and a wrong side and is arranged in such a way that, according to the invention, the right side is radially on the outside with reference to the wrong side of the knit.

[0122] Each knit 44 is such that the reinforcing elements 48 criss-cross with the loops B of one and the same column C.sub.i by passing from the right side to the wrong side every k rows R.sub.j and/or with the inter-loop elements E of two consecutive columns C.sub.i, C.sub.j of loops by passing from the right side to the wrong side every k rows R.sub.j. Preferably, k=1.

[0123] FIGS. 2 and 3 illustrate two embodiments of assemblies 44 and 44 according to the invention, in which the knit 46 is a weft knit made up of several filamentary elements. Only a portion of the assemblies is depicted, in which portion 4 columns and 4 rows of knit are illustrated.

[0124] In these two embodiments, each reinforcing element 48-i criss-crosses with the knit 46 between two consecutive columns C.sub.i, C.sub.i+1.

[0125] In this particular instance, each reinforcing element 48-i criss-crosses with the inter-loop elements E.sub.i,j, of two consecutive columns of loops, these inter-loop elements E.sub.i,j, connecting two loops belonging to the consecutive columns C.sub.i and C.sub.i+1.

[0126] In addition, each reinforcing element 48-i criss-crosses with inter-loop elements of each pair of consecutive columns of loops and with each inter-loop element of two consecutive columns of loops.

[0127] In addition, all the reinforcing elements criss-cross in phase with the inter-loop elements of loops of one and the same row.

[0128] Each knit 44 in FIGS. 2 and 3 is such that the reinforcing elements 48 criss-cross with the inter-loop elements E of two consecutive columns C.sub.i, C.sub.j of loops by passing from the right side to the wrong side at each row R.sub.j. In other words, that means that each reinforcing element 48-i criss-crosses on the wrong (or right) side of the inter-loop element E.sub.i,j and on the right (or wrong) side of the inter-loop element E.sub.i,j+1 of the next row.

[0129] With reference to FIG. 2, the reinforcing element 48-1 criss-crosses: [0130] behind the inter-loop element E.sub.2,3 of row R2, [0131] in front of the inter-loop element E.sub.2,3 of row R3, and [0132] behind the inter-loop element E.sub.2,3 of row R4.

[0133] This criss-crossing repeats for all the reinforcing elements, particularly for 48-2 and 48-3.

[0134] Thus, in the embodiment illustrated in FIG. 2, all the reinforcing elements 48 of the fabric of FIG. 2 criss-cross in phase with the inter-loop elements of loops of each row R.sub.j.

[0135] With reference to FIG. 3, the reinforcing element 48-2 criss-crosses: [0136] in front of the inter-loop element E.sub.2,3 of row R2, [0137] behind the inter-loop element E.sub.2,3 of row R3, and [0138] in front of the inter-loop element E.sub.2,3 of row R4.

[0139] By contrast, each reinforcing element 48-1 and 48-3 criss-crosses: [0140] behind the inter-loop element E.sub.1,2 and E.sub.3,4 of row R2, [0141] in front of the inter-loop element E.sub.1,2 and E.sub.3,4 of row R3, and [0142] behind the inter-loop element E.sub.1,2 and E.sub.3,4 of row R4.

[0143] Thus, in the embodiment illustrated in FIG. 3, pairs of reinforcing elements 48-i are in phase opposition, which means to say that, for each pair of consecutive reinforcing element 48-i, 48-j, the two reinforcing elements 48-i, 48-j criss-cross in phase-opposition with the inter-loop elements of loops of one and the same row R.sub.j.

[0144] Of course, in other alternative forms, each reinforcing element 48-i may criss-cross with the loops B or the inter-loop elements E.sub.i,j at regular intervals of rows of the knit 46, for example every k rows, with k>2. Thus, each reinforcing element 48-i may criss-cross with the knit 46 in the following way in the case of reinforcing elements 48 that are in phase: [0145] behind the inter-loop element E.sub.i,j of the rows R.sub.j, R.sub.j+k, R.sub.j+2k . . . [0146] in front of the inter-loop element E.sub.i,j of the rows R.sub.j+1, R.sub.j+1+k, R.sub.j+1+2k . . .

[0147] In the case of reinforcing elements 48 in phase-opposition, each reinforcing element 48 may criss-cross with the knit 46 in the following way: [0148] behind the inter-loop element E.sub.i,j of the rows R.sub.j, R.sub.j+k, R.sub.j+2k . . . in the case of the reinforcing elements 48-m, [0149] in front of the inter-loop element E.sub.i+1,j+1 of the rows R.sub.j, R.sub.j+k, R.sub.j+2k . . . in the case of the reinforcing elements 48-2m, [0150] in front of the inter-loop element E.sub.i,j of the rows R.sub.j+1, R.sub.j+1+k, R.sub.j+1+2k . . . in the case of the reinforcing elements 48-m, [0151] behind the inter-loop element E.sub.i+1,j+1 of the rows R.sub.j+1, R.sub.j+1+k, R.sub.j+1+2k . . . in the case of the reinforcing elements 48-2m.

[0152] Thus, all the reinforcing elements 48 may criss-cross in phase or in phase opposition, with a certain recurrence.

[0153] FIGS. 4 and 5 illustrate two other embodiments of assemblies 54 and 54 according to the invention, in which the knit 56 is a warp knit made up of several filamentary elements knitted together. Only a portion of the assemblies is depicted.

[0154] The knits are identical for the two embodiments illustrated. The knits are warp knits of jersey construction.

[0155] Unlike in the embodiments illustrated in FIGS. 2 and 3, each reinforcing element 48-i of the knits 56 in FIGS. 4 and 5 criss-crosses with the inter-loop elements E.sub.i,j of two consecutive columns of loops, each inter-loop element E.sub.i,j connecting two loops belonging to two consecutive columns of loops and belonging to two consecutive rows of loops. Thus, each inter-loop element E.sub.i,j connects the loops B.sub.i,j and B.sub.i+1,j+1.

[0156] FIGS. 6 and 7 are photographs respectively of the right and wrong sides of one and the same assembly 64 according to a fifth embodiment of the invention. The knit 66 has been produced on a warp knitting machine said to be fully threaded, which means that all of the heddle hooks, each secured to a support known as a bar, has a filamentary element in its needle. The various filamentary elements are worked according to the following bar movement coding: Bar 1: 10/01//Bar 2: 10/23//Bar 3: 00//Bar 4: 00/11/00/22/11/22//. In what follows, this coding is referred to as type 3 coding.

[0157] In the preceding embodiments, the knit is made up of several filamentary elements of textile material coated with a layer of tackifying adhesive of RFL type.

[0158] Each reinforcing element comprises a multifilament strand comprising several elementary monofilaments made of a metallic or textile material. In the case of the assemblies of FIGS. 2, 3, 4 and 5, each reinforcing element is made up of two textile multifilament strands wound around one another, for example made of aramid, of polyester or of nylon. In the case of FIGS. 6 and 7, each reinforcing element comprises, in this instance consists of, a cord of structure 3+9, each elementary monofilament being a metal wire having a diameter equal to 0.18 mm.

[0159] FIG. 8 depicts a tire according to a second embodiment of the invention. Unlike the tire according to the first embodiment, in the tire of FIG. 8, the protective ply 19 is interposed radially between the working plies 16, 18. In the alternative form depicted in FIG. 8, and just as with the tire according to the first embodiment, the protective ply 19 comprises the assembly, reinforcing elements 48 of the assembly forming the protective reinforcing elements of the protective ply 19. In another alternative form that has not been depicted, one of the working plies 16, 18, in this instance 16, comprises the assembly, the reinforcing elements of the assembly forming the working reinforcing elements of the working ply 16, 18. It could equally be the ply 18. In yet another alternative form, each working ply 16, 18 comprises an assembly, the reinforcing elements 48 of each assembly forming the working reinforcing elements of each working ply 16, 18.

[0160] FIG. 9 depicts a tire according to a third embodiment of the invention. Unlike the tire according to the first embodiment, in the tire of FIG. 9, the crown reinforcement 14 is made up of a working reinforcement 15 comprising two working plies. In other words, the crown reinforcement 14 has no protective reinforcement. In the alternative form depicted in FIG. 9, one of the working plies 16, 18, in this instance 16, comprises the assembly, the reinforcing elements 48 of the assembly forming the working reinforcing elements of the working ply 16. It could equally be the ply 18. In another possible, but not depicted, alternative form, each working ply 16, 18 comprises an assembly, the reinforcing elements 48 of each assembly forming the working reinforcing elements of each working ply 16, 18.

[0161] Comparative Tests

[0162] Tire plies according to the invention and a ply of a control tire T0 according to the prior art were compared.

[0163] The knits tested were manufactured to two different bar movement codings, a type 1 coding and a type 3 coding. The type 3 coding corresponds to the one described with reference to the fifth embodiment of the invention described hereinabove and illustrated in FIGS. 6 and 7. The type 1 coding is as follows: Bar 1: 10/01//Bar 2: 00/11/00/33/22/33//Bar 3: 00//Bar 4: 22/11/22/00/11/00//.

[0164] The ply of tire T0 comprises an elastomer matrix in which are embedded metallic cords of structure 3+9, each metal filament having a diameter equal to 0.18 mm.

[0165] Each ply of each tire T1 to T6 according to the invention comprises an elastomer matrix in which is embedded a knit filled with reinforcing elements. Each reinforcing element is a filamentary element comprising a single multifilament strand comprising several elementary monofilaments and in which each elementary monofilament is made from a textile material. The textile material is either aramid or nylon. The protective ply is produced by skimming the assembly between two elastomer strips 1 mm in width. The knit may or may not be coated with a coat of tackifying adhesive of RFL type. The knit is produced using one of the two codings described hereinabove and a given stitch density. The stitch density is determined in accordance with standard NF EN 14971.

[0166] Table 1 below summarizes the various characteristics of the plies tested.

TABLE-US-00001 TABLE 1 Reinforcing Density Tire Coding elements Coating (stitches/cm) T1 1 aramid RFL adhesive 8.2 T2 1 aramid RFL adhesive 5.3 T3 3 aramid RFL adhesive 5.3 T4 3 Nylon RFL adhesive 5.3 T5 1 Nylon RFL adhesive 8.2 T6 1 aramid 8.2

[0167] Puncture tests were carried out on each ply manufactured, during which tests each ply was exposed to an indenting tool which applied a set displacement load in such a way that the wrong side or the right side of the knit was exposed to the indenting tool. During the course of the tests, the plies were fixed to a rigid support and the indenting tool was fixed to a load cell. The indenting tool was a nail with a cylindrical and longitudinal body 4.5 mm in diameter and a head of conical shape with cone angle 30 and a flat end 1 mm in diameter. The indenting tool was moved into contact with the ply until the ply was punctured. The variation in the force applied to the ply as a function of the movement was measured.

[0168] The value of the puncturing force corresponds to the maximum load applied to the ply up to the point just before it becomes punctured. The puncture force values for the plies containing the assemblies tested are summarized in Table 2 below.

TABLE-US-00002 TABLE 2 Tire Puncture force (N) T0 101.8 Puncture force (N) Puncture force (N) Tire right side wrong side T1 388.4 343.5 T2 314.4 253.8 T3 413.4 336.3 T4 305.7 256.9 T5 273.8 257.1 T6 344.4 339.0

[0169] It is noted that the ply of the tire according to the invention withstands a maximum puncture load that is far higher than the ply of the control tire. Specifically, the maximum puncture load is 2.5 to 4.1 times higher in the assemblies of the tires according to the invention (T1 to T6) as compared with the control T0.

[0170] Furthermore, it should also be noted that the direction in which the assembly is laid plays an essential role in the puncture tests. Specifically, the puncture forces are greater when the indenter comes into contact with the right side of the assembly.

[0171] The invention is not limited to the embodiments described above.

[0172] Specifically, the assembly formed by the knit filled with the reinforcing elements could be arranged in other locations in the tire than those described hereinabove, for example in the carcass reinforcement, in the hoop reinforcement or even in the lower sidewall, for example in the bead.

[0173] In an embodiment which has not been illustrated, each reinforcing element is a filamentary element made up of a metallic monofilament. The metallic monofilament then has a diameter in the range from 0.10 mm to 0.40 mm.

[0174] In an embodiment which has not been illustrated, each reinforcing element is a filamentary reinforcing element made up of two textile multifilament strands wound around one another.

[0175] It will also be possible to combine the characteristics of the various embodiments described or envisaged above, with the proviso that these characteristics are compatible with one another.