Method of making footwear having a two-color rubber sole

Claim 2

In a method of molding rubber onto an article, the steps of: placing unvulcanized rubber in a mold cavity defined on the one hand by said article and on the other hand by closed side wall means having an adjunct thereof in engagement with said article and by a movable mold member located within the confines of said side wall means opposite said article, said movable mold member having a peripheral lip in sliding contact with said side wall means in the closed condition of the latter and further having a continuous peripherally disposed groove adjacent said lip to the side thereof facing in the direction away from said article; advancing said movable mold member within said side wall means in the closed condition of the latter toward said article until the rubber is spread against said article, and until rubber escaping between said lip and said side wall means at least partially fills the space defined by said groove so as to define a circumferentially extending bead; permitting said rubber to at least partially set and become vulcanized to said article with the portion between said lip and said side wall means forming a peripherally extending weakened region connecting the rubber in said cavity and the bead-constituting rubber in said groove; retracting said movable mold member in said direction away from said article while maintaining said side wall means in the closed condition thereof, said side wall means coacting with said movable mold member during such retracting movement of the latter to positively confine said bead located in said groove against escape from said groove, thereby positively entraining said bead into movement with said movable mold member so as to tear said bead cleanly from the remainder of said rubber along said weakened region; thereafter, with said bead having been retained in said groove while said movable mold member was being retracted, introducing additional rubber into said cavity after retraction of said movable mold member; again advancing said movable mold member toward said article with said side wall means still in the closed condition thereof until said additional rubber is spread against the first-named rubber vulcanized to said article; and permitting said additional rubber to set and become vulcanized to said first-named rubber vulcanized to said article; said bead serving as a flash-limiting sealing member during the entire second molding operation.

Claim 3

The method according to claim 1, wherein the peripheral face of said movable mold member to the side of said lip facing in the direction toward said article is slanted inwardly away from said side wall means, the peripheral flange of said first-named rubber formed in that region during the first molding operation thereby decreasing in thickness toward, and having an inner surface slanting outwardly as viewed in the direction of, said weakened region, whereby said additional rubber, when spread during the second advance of said movable mold member, is forced against said slanted inner surface of said flange and presses the latter tightly against said side wall means so as to prevent any of said additional rubber from being deposited on and vulcanized to the outer surface of said flange.

Claim 4

In a method for the manufacture of two-color rubber-soled footwear, the steps of: introducing a measured quantity of a first uncured rubber into a mold cavity defined by closed side ring means, a lasted upper, and a sole plate having a peripheral lip in sliding contact with the inside surface of said side ring means and provided adjacent said lip to the side thereof facing away from said lasted upper with a groove extending around the entire periphery of said sole plate and opening toward said side ring means; advancing said sole plate within said closed side ring means toward said lasted upper until said first rubber is spread throughout the entire mold cavity and any of said first rubber escaping between said lip of said sole plate and said side ring means at least partially fills said groove; permitting said first rubber to at least partially set so as to have the portion thereof in contact with said lasted upper become a midsole component vulcanized to said lasted upper while the portion of said first rubber in said groove becomes a continuous bead having a cross-sectional thickness substantially larger than the peripheral region of least cross-sectional thickness formed by the escaping rubber between said lip and said side ring means; retracting said sole plate in a direction away from said lasted upper while maintaining said side ring means in the closed condition thereof, said side ring means coacting with said sole plate during such retraction movement of the latter to positively confine said bead located in said groove against escape from the latter, thereby entraining said bead into movement with said sole plate so as to cleanly tear said bead away from said portion of said first rubber forming said midsole component along said peripheral region of least cross-sectional thickness; introducing into the mold cavity, after said sole plate has been retracted from said midsole component, a measured quantity of a second rubber having a color different from that of said first rubber; and once more advancing said sole plate, together with the now severed bead of said first-named rubber in said groove and while said side ring means are still in the closed condition thereof, toward said lasted upper until said second rubber is spread against said midsole component to form an outsole component thereon; said bead serving as a flash-inhibiting sealing member during the entire second molding operation.

Claim 5

In a method for the manufacture of two-color rubber-soled footwear, the steps of: introducing a measured quantity of a first uncured rubber into a mold cavity defined by closed side ring means, a lasted upper, and a sole plate having a peripheral lip in sliding contact with the inside surface of said side ring means and provided adjacent said lip to the side thereof facing away from said lasted upper with a groove extending around the entire periphery of said sole plate and opening toward said side ring means; advancing said sole plate within said closed side ring means toward said lasted upper until said first rubber is spread throughout the entire mold cavity and any of said first rubber escaping between said lip of said sole plate and said side ring means at least partially fills said groove; permitting said first rubber to at least partially set so as to have the portion thereof in contact with said lasted upper become a midsole component vulcanized to said lasted upper while the portion of said first rubber in said groove becomes a continuous bead having a cross-sectional thickness substantially larger than the peripheral region of least cross-sectional thickness formed by the escaping rubber between said lip and said side ring means; retracting said sole plate in a direction away from said lasted upper while maintaining said side ring means in the closed condition thereof, said side ring means coacting with said sole plate during such retraction movement of the latter to positively confine said bead located in said groove against escape from the latter, thereby entraining said bead into movement with said sole plate so as to cleanly tear said bead away from said portion of said first rubber forming said midsole component along said peripheral region of least cross-sectional thickness; introducing into the mold cavity, after said sole plate has been retracted from said midsole component, a measured quantity of a second rubber having a color different from that of said first rubber; and once more advancing said sole plate, together with the now severed bead of said first-named rubber in said groove and while said side ring means are still in the closed condition thereof, toward said lasted upper until said second rubber is spread against said midsole component to form an outsole component thereon; said bead serving as a flash-inhibiting sealing member during the entire second molding operation.

Claim 6

The method according to claim 3, wherein the peripheral face of said sole plate to the side of said lip facing in the direction toward said lasted upper is slanted inwardly away from said side ring means, the peripheral foxing component of said midsole component formed in that region during the first molding operation thereby decreasing in thickness toward, and having an inner surface slanting outwardly as viewed in the direction of, said region of least cross-sectional thickness, whereby said second rubber, when spread during the second advance of said sole plate, is forced against said slanted inner surface of said foxing component and presses the same tightly against said side ring means so as to prevent any of said second rubber from being deposited on and vulcanized to the outer surface of said foxing component.