Apparatus for reducing tangential force variation in pneumatic tires

摘要

A method and apparatus for reducing tangential force variation in a pneumatic tire wherein the tire is mounted on a wheel rim, inflated to operating pressure, and rotated under a predetermined load against a loading drum. Force transducers on the axis of the loading drum measure the tangential force variation as the tire rotates. These measurements are placed into the memory of a computer. The computer processes this data to obtain the magnitude of the tangential force variation and the phase angle from an arbitrary location of the variation or the angular displacement to the point of maximum magnitude. The computer outputs a V-shaped ramp voltage level signal for controlling the servo-valve which moves a rotary grinder into grinding engagement with the inner tread ribs of the tire. The grinding is repeated for a number of revolutions depending upon the magnitude of the variation.