Abstract: In apparatus for grinding arc portions of parts of the width of a tire tread, apparatus for controlling tilt of the grinding wheels relative to the tire rotation plane makes use of three paddles having arc contours for lengthened contact with the circumference of the tire tread and means for adjusting the location of the contour relative to the tire and grinding wheel centers to accommodate differences in diameter of one tire from another.The foregoing abstract is not to be taken as limiting the invention of this application, and in order to understand the full nature and extent of the technical disclosure of this application, reference must be made to the accompanying drawing and the following detailed description.

Abstract: The surface appearance of a tire tread finished by grinding to alleviate force variations in the tire is improved by reversing the grinding mode of one of the usual two grinding wheels. The effect is particularly useful in tires having large open block pattern treads as in mud and snow tires.