Cable for anchoring a tire carcass
AssigneeSedepro
InventorsPedro Costa Pereira, Jean-Claude Arnaud
Life of this patent
Estimating the term…
Abstract
The anchoring of the carcass reinforcing elements 1 is assured by circumferential cables 2, with the interposition of a connecting rubber composition 3. The circumferential cable 2 is arranged in several turns forming one or more helices. These circumferential cables have an operational elongation rate Af=Ae+Ap of more than 4%. This operational elongation rate does not include the specific elongation As of the “cable” effect. The maximum stress Rm of the cable 2 is preferably more than 2000 MPa. The cables have undergone a heat treatment which has, in combination, the features of being a recovery annealing treatment and which is carried out directly on cable comprising wires previously separately covered by an adherent coating.
Claims18
A tire comprising sidewalls which terminate in beads, the beads being designed to be mounted on a rim, said tire comprising a carcass reinforcement which passes in the sidewalls and joins the beads, at least one of said beads comprising:
- carcass reinforcing elements extending from the radially lower part of the bead towards the sidewall;
- at least one pile of circumferential cable laterally bordering the carcass reinforcing elements, said circumferential cable having an operational elongation rate Af of more than 4%, and
- a rubber mix between the circumferential cables and the carcass reinforcing elements.
A method of preparing a tire cable in which, starting from a cable of work-hardened steel wire, the carbon content of which is between 0.4% and 1.0%, covered with an adherent coating favoring adhesion between the steel and the rubber, said cable is subjected to a recovery annealing heat treatment at a temperature between 250° C. and Ac1 for a period of time to bring the operational elongation rate Af to a value of more than 4%, and using means such that, by controlling the ability of such a cable to adhere to a so-called “test” rubber mix before and after said preparation, the decline observed is less than or equal to 60%.
A tire having sidewalls terminating in beads, the beads being designed to be mounted on a rim, said tire having a carcass reinforcement which passes into the sidewalls and joins the beads, at least one of said beads comprising:
- carcass reinforcing elements extending from the radially bottom part of the bead towards the sidewall,
- at least two piles of circumferential reinforcing elements laterally bordering the carcass reinforcing elements, the radially lowermost part of the pile axially furthest to the outside being radially higher than the radially lowermost part of the adjacent pile.
A tire comprising sidewalls terminating in beads, the beads being designed to be mounted on a rim, said tire having a carcass reinforcement passing into the sidewalls and joining the beads, at least one of said beads comprising:
- carcass reinforcing elements extending from the radially bottom part of the bead towards the sidewall,
- at least two piles of circumferential reinforcing elements laterally bordering the carcass reinforcing elements,
- materials such that e1j is the thickness of each product which radially separates the radially lowermost helix of any pile from the radially lower face of the bead, and that e2i is the thickness of each product which radially separates the radially lowermost helix of any pile from the axially inner face of the bead, and that G1j and G2i are the effective Young's moduli of the products in question, said materials satisfying the following relationship:
- 3 ∑ i e 2 i * G 2 i ≤ ∑ j e 1 j * G 1 j .
Dependencies are inferred from the claim text.