Abstract: The apparatus for improving tire uniformity includes contra-rotating grinding wheels for removing tire material from the upper and lower shoulder portions of the tire. The grinders are moved into grinding engagement with the tire along a path that is defined by a radius of the tire to ensure that both grinding wheels at each shoulder of the tire make simultaneous contact with the tire. The amount and extent of grinding accomplished by the contra-rotating grinders is controlled by a grind control circuit. The grind control circuit measures the no-lead current level of the grinder motor and compares the no-load current level with the current level when the grinder motors are under load. When the grinder current under load is above a predetermined maximum load current, the control circuit will signal the grinders to retract from engagement with the tire until the load current drops below the predetermined maximum level.

Abstract: Apparatus and method for marking a rotating tire, for example, to indicate the point of maximum radial force variation. The apparatus includes a marker head which is pivotable into contact with an inking pad in a direction similar to the direction of rotation of the tire at the point of contact of the marker head with the tire and which is also retractable from the tire.

Abstract: A method and apparatus for determining the conicity of a tire wherein, while the tire is being corrected for radial force variation by grinding as it revolves in a first direction, the lateral thrust force of the lateral force variation is determined and stored. The tire is revolved in a second direction and the lateral thrust force is determined. The conicity of the tire is calculated by use of the post grinding lateral thrust force values and then is compared to a predetermined maximum allowable conicity. The tire is graded accordingly. Associated circuity and apparatus are disclosed.

Abstract: A pivotable sensor shoe in a tire grinding machine for tracking the tread surface of a pneumatic tire. The sensor shoe comprises a pivot point and a curved tracking surface. The tracking surface includes a minimum length long enough to provide point contact with the tread surface at opposite ends of the tracking surface length. The tracking surface has an arc whose radius is such that at least two point contact between the sensor tracking surface and the tire surface may be effected. This abstract is not to be taken as a complete position or as a limitation of the present invention, however, the full nature and extent of the invention being discernible only by reference to and from the entire disclosure.