Pneumatic tire comprising reinforcing metal wire cords with at least one shape memory wire and method of making same
AssigneePirelli Coordinamento Pneumatici S.p.A.
InventorsMarco Cipparrone, Gurdev Orjela, Guido Riva
Life of this patent
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Abstract
A metal cord for reinforcing articles made from elastomeric material comprises a plurality of metal wires wound spirally around each other. At least one of the metal wires is formed from a shape memory material, has capacities of recovering a previously memorized shape, and is deformed from the memorized shape. The shape memory wire of the cord has the recovery capacities substantially active in a first heat cycle and degraded to at least a significant predetermined extent after the first heat cycle. One or more such metal cords may be incorporated in pneumatic tires, reinforcing fabric, and other articles, including by means of processes described herein.
Claims13
A pneumatic tire for vehicle wheels, comprising a plurality of reinforcing cords, each formed by metal wires wound spirally around each other, at least one of which is formed from a shape memory material having capacities of recovering a previously memorized shape, each shape memory wire being deformed from the memorized shape, wherein the recovery capacities are substantially active in a first heat cycle and degraded to at least a significant predetermined extent after the first heat cycle.
A process for manufacturing a pneumatic tire for vehicle wheels, the tire comprising a casing of toroidal shape having a crown portion and two axially opposed sidewalls terminating in a pair of beads for fixing the tire to a corresponding mounting rim, a tread strip disposed on the crown of the casing and a belt structure interposed between the casing and the tread strip, the process comprising the steps of:
- preparing a raw type comprising a plurality of reinforcing cords, each formed by metal wires wound spirally around each other, at least one of which is a wire made from a shape memory material having capacities of recovering a previously memorized shape, each shape memory wire being deformed from the memorized shape;
- and
- vulcanizing the raw tire in a vulcanizing press by means of a first heat cycle defined by predetermined values of time, temperature, and pressure, wherein the recovery capacities are substantially active in the first heat cycle and are degraded to at least a significant predetermined extent after the first heat cycle, in such a way that the recovery capacities are substantially eliminated in each heat cycle following the vulcanization of the tire.
Dependencies are inferred from the claim text.