US Patent No. 10,336,026


Patent No. 10,336,026
Issue Date July 02, 2019
Title Use Of Vacuum To Increase Effective Skid Depth Of Pre-cured Tread
Inventorship E Bruce Colby, Simpsonville, SC (US)
Cesar Enrique Zarak, Greenville, SC (US)
Assignee Compagnie Generale des Etablissements Michelin, Clermont-Ferrand (FR)

Claim of US Patent No. 10,336,026

1. A method for increasing effective skid depth, comprising:providing a tire carcass having one or more worn original grooves on a surface thereof;
providing a pre-cured tread, comprising:
opposing top and bottom tread faces delineating a tread thickness coextensive therewith;
opposing lateral sides defining a tread width along which adjacent tread elements assume a tread sculpture;
one or more grooves provided on the top tread face with each groove terminating at a predetermined offset distance from the tread bottom face;
a network of channels incorporated along at least a portion of the tread bottom face; and
a thin undertread having a predetermined undertread thickness;
forming one or more groove hollows directly over corresponding original grooves of the carcass, with the groove hollows formed to match locations of the one or more grooves provided on the top tread face;
applying at least one layer of a bonding material between the bottom tread face and the carcass; and
curing the at least one layer of the bonding material without an envelope and evacuating gas along the channel network to force the tread onto the carcass and pull the undertread into the one or more groove hollows that are in fluid communication with the channel network such that a resultant skid depth is at least equal to a molded tread thickness of the pre-cured tread;
wherein forming the groove hollows deepens the original grooves by a predetermined net depth.