Cable with Three Layers, Rubberized On Site, for the Framework of a Tire Carcass
Metal cord (C- 1 ) with three layers (C 1, C 2, C 3 ), which is rubberized in situ, comprising a core or first layer ( 10, C 1 ) of diameter d 1 , around which there are wound together in a helix at a pitch p 2 , in a second layer (C 2 ), N wires ( 11 ) of diameter d 2 , around which there are wound together in a helix at a pitch p 3 , in a third layer (C 3 ), P wires ( 12 ) of diameter d 3 , wherein the cord has the following characteristics (d 1 , d 2 , d 3 , p 2 and p 3 being expressed in mm): 0.08≦d 1 ≦0.50; 0.08≦d 2 ≦0.45; 0.08≦d 3 ≦0.45; 5.1π(d 1 +d 2 )<p 2 <p 3 <4.9π(d 1 +2d 2 +d 3 ); over any 2 cm length of cord, a rubber composition called “filling rubber” ( 13 ) is present in each of the capillaries ( 14 ) lying on the one hand between the core (C 1 ) and the N wires ( 11 ) of the second layer (C 2 ), and on the other hand between the N wires ( 11 ) of the second layer (C 2 ) and the P wires ( 12 ) of the third layer (C 3 ); the content of filling rubber ( 13 ) in the cord is comprised between 10 and 50 mg per gram of cord. Multi-strand cord at least one of the strands of which is a three-layered metal cord (C- 1 ) rubberized in situ.
1 . A metal cord with three layers, which is rubberized in situ, comprising a core or first layer of diameter d 1 , around which there are wound together in a helix at a pitch p 2 , in a second layer, N wires of diameter d 2 , around which there are wound together in a helix at a pitch p 3 , in a third layer, P wires of diameter d 3 , wherein the cord has the following characteristics (d 1 , d 2 , d 3 , p 2 and p 3 being expressed in mm):
0.08≦d 1 ≦0.50;
0.08≦d 2 ≦0.45;
0.08≦d 3 ≦0.45;
5.1π(d 1 +d 2 )<p 2 <p 3 <4.9π(d 1 +2d 2 +d 3 );
over any 2 cm length of cord, a rubber composition called “filling rubber” is present in each of the capillaries lying on the one hand between the core and the N wires of the second layer, and on the other hand between the N wires of the second layer and the P wires of the third layer;
the content of filling rubber in the cord is comprised between 10 and 50 mg per gram of cord.
2 . The cord according to claim 1 , wherein the rubber of the filling rubber is a diene elastomer.
3 . The cord according to claim 2 , wherein the diene elastomer is chosen from the group consisting of polybutadienes, natural rubber, synthetic polyisoprenes, copolymers of butadiene, copolymers of isoprene, and blends of these elastomers.
4 . The cord according to claim 3 , wherein the diene elastomer is an isoprene elastomer, preferably natural rubber.
5 . The cord according to claim 1 , wherein the following characteristics are satisfied (with d 1 , d 2 , d 3 being in mm):
0.10≦d 1 ≦0.40;
0.10≦d 2 ≦0.35;
0.10≦d 3 ≦0.35.
6 . The cord according to claim 1 , wherein the following characteristics are satisfied:
for N=5: 0.6<(d 1 /d 2 )<0.9;
for N=6: 0.9<(d 1 /d 2 )<1.3;
for N=7: 1.3<(d 1 /d 2 )<1.6.
7 . The cord according to claim 1 , wherein the N and P wires of the second and third layers are wound in the same direction of twisting.
8 . The cord according to claim 1 , wherein p 2 and p 3 are comprised in a range from 5 to 30 mm.
9 . The cord according to claim 1 , wherein d 2 =d 3 .
10 . The cord according to claim 1 , wherein the second layer comprises 5, 6 or 7 wires.
11 . The cord according to claim 1 , wherein the third layer comprises 10 to 14 wires.
12 . The cord according to claim 1 , wherein the third layer is a saturated layer.
13 . The cord according to claim 1 , wherein the core consists of a single wire.
14 . The cord according to claim 13 , of 1+6+11 or 1+6+12 construction.
15 . The cord according to claim 1 , wherein the content of filling rubber is comprised between 15 and 50 mg per g of cord.
16 . The cord according to claim 1 , wherein, in an air permeability test (according to paragraph I-2), it has an average air flow rate of less than 2 cm 3 /min.
17 . The cord according to claim 16 , wherein, in the air permeability test (according to paragraph I-2), it has an air flow rate less than or at the most equal to 0.2 cm 3 /min.
18 . A multi-strand rope at least one of the strands of which is a cord according to claim 1 .
19 . (canceled)
20 . (canceled)
21 . A tire comprising a cord according to claim 1 .
22 . The tire according to claim 21 , said tire being a tire of an industrial vehicle.
23 . The tire according to claim 21 , the cord being present in the carcass reinforcement of the tire.