Patent ID: 6632393
Filing Date: 2003-10-14
Classification: B29D

Abstract:
Segmental mold apparatus for curing a radial tire from an uncured rubber tire body having a tire bead area, and upper and lower sidewall portions that extend radially outwardly to a tread portion which encases a multi-cord belt package, said mold apparatus including:a top mold section and a bottom mold section, said top mold section being vertically movable with respect to the bottom mold section from a raised open tire body-receiving position to a lower closed tire body-molding position; the top mold section and the bottom mold section including upper and lower sidewalls, respectively, which extend substantially the entire distance from the tire bead area to the periphery of the tread portion of an uncured tire body; the top mold section supporting a plurality of radially and axially movable top tread segments having tread-defining lugs on their radially inner portions; the bottom mold section supporting a plurality of bottom tread segments having tread-defining lugs on their radially inner portions; springs interposed between the top mold section and the top tread segments biasing the top tread segments downwardly and outwardly to a position wherein their lugs are disposed outwardly of and adjacent to the periphery of the tread portion; springs interposed between the bottom mold section and the bottom tread segments biasing the bottom tread segments upwardly and outwardly to a position wherein their lugs are disposed radially outwardly of and adjacent to the outer periphery of the tire body's tread portion when the top mold section is in its raised position; with the lower sidewall portion of the bottom mold section supporting the entire lower sidewall and tread portion of the uncured rubber tire body without any deformation of the cords of the multi-cord belt package when the top mold section is in its raised position; camming surfaces on the top mold section which engage the top tread segments thereby forcing the top tread segments downwardly and radially inwardly urging their lugs into tread molding engagement with the tread portion of the uncured tire body as the top mold section is lowered from its raised position towards its closed position, with the top tread segments engaging the bottom tread segments during such downward movement of the top mold section to force the bottom tread segments downwardly and radially inwardly urging their lugs into tread molding engagement with the tread portion of the uncured tire body as the top mold section is lowered from its raised position to its lowered position whereby the lugs of the top and bottom tread segments will form tread grooves in the tread portion of the uncured tire body.