Method and Device for Manufacturing a Three-Layer Cord of the Type Rubberized in Situ

Abstract

Method of manufacturing a metal cord with three concentric layers (C1, C2, C3), rubberized in situ, of M+N+P construction, comprising a first, internal, layer (C1) consisting of M wires of diameter d1, M varying from 1 to 4, around which there are wound together in a helix, at a pitch p2, in a second, intermediate, layer (C2), N wires of diameter d2, N varying from 3 to 12, around which there are wound together as a helix at a pitch p3, in a third, outer, layer (C3), P wires of diameter d3, P varying from 8 to 20, the said method comprising the following steps which are performed in line: an assembling step by twisting the N wires around the first layer (C1) in order to form, at a point named the “assembling point”, an intermediate cord named a “core strand” of M+N construction; downstream of the assembling point, a sheathing step in which the M+N core strand is sheathed with a rubber composition named “filling rubber” in the uncrosslinked state; an assembling step in which the P wires of the first layer (C3) are twisted around the core strand thus sheathed; a final twist-balancing step. Also disclosed is a device for implementing such a method.

Dependencies are inferred from the claim text.