Patent ID: 8584721
Filing Date: 2013-11-19
Classification: B60C,Y10T

Abstract:
1. A tire having a rotation timing indication hole comprising a multi-step hole extending in a depth wise direction into a tread of the tire, wherein the multi-step hole is bounded by a peripheral sidewall having (1) an outer step with a peripheral edge (a) extending continuously and completely about the hole at the tread surface and (b) circumscribing a first cross-sectional area of the hole and (2) an inner step with a peripheral edge (a) completely surrounding a lower section of the hole, (b) circumscribing a second cross-sectional area of the hole that is smaller than the first cross-sectional area and (c) located at a greater depth in the tread than the peripheral edge of the outer step; the outer step and the peripheral edge of the outer step have a contour that forms a circle; the inner step and the peripheral edge of the inner step have a contour that forms a regular polygon with four or fewer sides, the contour of the inner step and the peripheral edge of the inner step being inscribed on the contour of the outer step and the peripheral edge of the outer step, whereby the contour of the inner step and the peripheral edge of the inner step consists of (1) peripherally spaced points that are coincident with the contour of the outer step and the peripheral edge of the outer step and (2) segments between the peripherally spaced points that are spaced inwardly from the contour of the outer step and the peripheral edge of the outer step; and the outer step and the inner step have depths separately representative of different degrees of wear of a tread surface until tire rotation timing; whereby when the tire is in an unworn state, the contour of the outer step will be discernible at the tread surface and will be indicative of an unworn state of the tread, and when the tire has undergone predetermined wear, the different contour of the inner step will be discernible at the tread surface and will be indicative of a predetermined state of wear of the tread.