Patent ID: 8021136

Claim:
Preparing a plurality of plates which will define an interior tread pattern within a tire mold, said plates having an inner predetermined radius, an outer predetermined radius, and substantially parallel sides extending between said inner radius and said outer radius, comprising the steps of a) machining at least one discrete region to a shallow depth on at least one side of the plates from its inner radius part way toward its outer radius, b) thereafter stacking and securing the machined plates together with the inner radius' of abutting plates extending in a circumferential direction and thereby producing first gaps at the discrete regions between the surfaces of adjacent plates, the first gaps extending substantially radially from the inner radius toward the outer radius, c) forming second gaps at a depth and width greater than the first gaps and extending directly from, with no intermediate passageways, connecting with an in alignment to the first gaps in the outer full thickness region of the plates, to form vent passages between adjacent plates in a depth of approximately 0.060 inches and extending from the first gaps to the outer radius of the plates, and thus venting outward through the stacked plates to the back of the mold.