Abstract: A method and apparatus for grooving a tire tread in which a computerized numerical controller regulates the positional relationships between the tire and a hot cutting knife. The controller, through a plurality of servo motors, causes the tire to rotate in a vertical plane while effecting lateral and rotational movement of the cutter knife in each of two planes. During the cutting operation, the controller regulates the temperature of the cutting knife in accordance with the contour of the cut and the rate at which it is being made. Additionally, the computerized numerical controller is operator-programmable, providing for the generation of a program while the knife is caused to trace a tread design. The method and apparatus achieves simultaneous five-axis control of the tire grooving operation with concurrent regulation of the knife temperature.

Abstract: System for testing pneumatic tires. A tire that revolves under a load is deformed at the area in which it meets the roadway. Such a deformation results in the tire having an effective rolling radius that is shorter than the radius it has while static and/or unloaded. According to the invention, tires are tested by determining their effective rolling radii. When tires having similar effective rolling radii are used on an automotive vehicle, the undesirable torque steer effect is thereby reduced.