Three-Layered Metal Cable For Tire Carcass Reinforcement
The present invention relates to a three-layered metal cable of construction L+M+N usable as a reinforcing element for a tire carcass reinforcement, comprising an inner layer C 1 having L wires of diameter d 1 with L being from 1 to 4, surrounded by an intermediate layer C 2 of M wires of diameter d 2 wound together in a helix at a pitch p 2 with M being from 3 to 12, said layer C 2 being surrounded by an outer layer C 3 of N wires of diameter d 3 wound together in a helix at a pitch p 3 with N being from 8 to 20, said cable being characterised in that a sheath formed of a cross-linkable or cross-linked rubber composition based on at least one diene elastomer covers at least said layer C 2 . The invention furthermore relates to the articles or semi-finished products made of plastics material and/or rubber which are reinforced by such a multi-layer cable, in particular to tires used in industrial vehicles, more particularly heavy-vehicle tires and their carcass reinforcement plies.
1 - 38 . (canceled)
39 . A tire comprising:
a carcass reinforcement, which is anchored at two beads;
a crown reinforcement positioned radially above the carcass reinforcement;
a tread positioned radially above the crown reinforcement, the tread being joined to the two beads by two sidewalls,
wherein the carcass reinforcement includes at least one three-layered metal cable, each of the at least one three-layered metal cable including:
an inner layer C 1 , which includes from 1 to 4 wires L having a diameter d 1 , an intermediate layer C 2 , which surrounds the inner layer C 1 , wherein the intermediate layer C 2 includes from 3 to 12 wires M having a diameter d 2 , and wherein the wires M are wound together in a helix at a pitch p 2 ,
an outer layer C 3 , which surrounds the intermediate layer C 2 , wherein the outer layer C 3 includes from 8 to 20 wires N having a diameter d 3 , and wherein the wires N are wound together in a helix at a pitch p 3 , and
a rubber sheath formed of a cross-linkable or cross-linked rubber composition that includes at least one diene elastomer, wherein the rubber sheath covers at least the intermediate layer C 2 .
40 . A tire according to claim 39 , wherein the at least one diene elastomer of the rubber sheath is selected from a group of elastomers that includes polybutadienes, natural rubber, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers, and mixtures thereof.
41 . A tire according to claim 40 , wherein the at least one diene elastomer is selected from a group of elastomers that includes natural rubbers, synthetic polyisoprenes, and mixtures thereof.
42 . A tire according to claim 41 , wherein the at least one diene elastomer is a natural rubber.
43 . A tire according to claim 39 , wherein the rubber composition includes a carbon black as a reinforcing filler.
44 . A tire according to claim 39 , wherein the rubber composition has, in a cross-linked state, a secant tensile modulus that is less than 20 MPa.
45 . A tire according to claim 44 , wherein the secant tensile modulus is less than 12 MPa.
46 . A tire according to claim 39 ,
wherein each of the at least one three-layered metal cable is incorporated into a carcass reinforcement ply of a tire that includes a rubber matrix, and
wherein the rubber matrix of the carcass reinforcement ply includes substantially a same rubber composition as the rubber composition of the rubber sheath of each of the at least one three-layered metal cable.
47 . A tire according to claim 39 , wherein outer layer C 3 is a saturated layer.
48 . A tire according to claim 39 , wherein the rubber sheath covers the inner layer C 1 .
49 . A tire according to claim 39 , wherein the rubber sheath is structured to separate adjacent wires of the wires M in the intermediate layer C 2 .
50 . A tire according to claim 39 ,
wherein the rubber sheath covers a radially inner half-circumference of each wire of the wires N of the outer layer C 3 , and
wherein the rubber sheath separates the adjacent wires of the wires N of the outer layer C 3 .
51 . A tire according to claim 39 , wherein the intermediate layer C 2 includes 6 or 7 of the wires M.
52 . A tire according to claim 39 , wherein:
0.10 mm<d 1 <0.28 mm;
0.10 mm<d 2 <0.25 mm;
0.10 mm<d 3 <0.25 mm;
M=6 or M=7;
5π(d 1 +d 2 )<p 2 ≦p 3 <5π(d 1 +2d 2 +d 3 ); and
the wires M of the intermediate layers C 2 and the wires N of the outer layer C 3 are wound in a same direction of twist.
53 . A tire according to claim 52 , wherein:
if M is 6, then a ratio (d 1 /d 2 ) is from 1.10 to 1.40; and
if M is 7, then the ratio (d 1 /d 2 ) is from 1.40 to 1.70.
54 . A tire according to claim 53 , wherein p 2 =p 3 .
55 . A tire according to claim 54 , wherein the outer layer C 3 has a substantially circular cross-section.
56 . A tire according to claim 39 , wherein the inner layer C 1 includes 1 wire L.
57 . A tire according to claim 56 , wherein a wire composition of each of the at least one three-layered metal cable is selected from a group that includes:
6 of the wires M in the intermediate layer C 2 , and 10 of the wires N in the outer layer C 3 ;
6 of the wires M in the intermediate layer C 2 , and 11 of the wires N in the outer layer C 3 ;
6 of the wires M in the intermediate layer C 2 , and 12 of the wires N in the outer layer C 3 ;
7 of the wires M in the intermediate layer C 2 , and 11 of the wires N in the outer layer C 3 ;
7 of the wires M in the intermediate layer C 2 , and 12 of the wires N in the outer layer C 3 ; and
7 of the wires M in the intermediate layer C 2 , and 13 of the wires N in the outer layer C 3 .
58 . A tire according to claim 57 , wherein the intermediate layer C 2 includes 6 of the wires M, and the outer layer C 3 includes 12 of the wires N.
59 . A tire according to claim 52 , wherein:
0.18 mm<d 1 <0.24 mm;
0.16 mm<d 2 <d 3 <0.19 mm; and
5 mm<p 2 <p 3 <12 mm.
60 . A tire according to claim 52 , wherein:
0.18 mm<d 1 <0.24 mm;
0.16 mm<d 2 <d 3 <0.19 mm; and
20 mm<p 2 ≦p 3 <30 mm.
61 . A tire according to claim 39 , wherein the rubber sheath has an average thickness of from 0.010 mm to 0.040 mm.
62 . A tire according to claim 39 , wherein the wire or wires L, the wires M, and the wires N include carbon steel.
63 . A tire according to claim 62 , wherein a carbon content of the carbon steel is from 0.4% to 1.0%.
64 . A tire according to claim 39 , wherein the tire is for an industrial vehicle.
65 . A tire according to claim 64 , wherein the tire is for a heavy vehicle.