Tire symmetry measuring method and system

Claim 1

Apparatus for simultaneously testing the symmetry and the non-uniformity characteristics of a vehicle wheel/tire under sImulated actual static load and at speeds characteristic of 6090 m.p.h., comprising: a frame member, a first shaft member mounted in said frame for rotation therein, a drum mounted on said first shaft, a second shaft member mounted in said frame, said second shaft adapted to support said wheel/tire in a perpendicular plane and parallel to said drum and in contact with said drum, means for varying the amount of contact between said wheel/tire and said drum to thereby simulate the actual static load necessary for said tire and thereby simulate the tire patch, said wheel shaft and said drum shaft in said frame having a fixed parallel dimension once said varying means is in a fixed position to provide a closed loop system, means for rotating said drum at peripheral velocities comparable to auto speeds of 60-90 m.p.h., a first piezoelectric sensor positioned in a first direction relative to said first shaft to sense and measure the radial forces at said tire patch of said tire under said simulated actual load and said speed of a vehicle, a second piezoelectric sensor positioned in a second direction at right angles to said first direction and at 90* displacement from said first sensor - to sense and measure the dynamic unbalance forces caused by lack of symmetry of said tire simultaneously with said first sensor, and means for utilizing said first and second sensed measurements.

Claim 12

The method of simultaneously testing the symmetry and non-uniformity characteristics of a vehicle wheel/tire utilizing a drum to obtain simulated actual static load and speeds characteristic of 60-90 m.p.h. comprising steps of: supporting said wheel/tire and said drum in a fixed distance closed loop arrangement upon parallel axles, varying the position of said drum to simulate a static load on said drum and thereby creating a tire patch, rotating said drum at peripheral velocities characteristic of 60-90 m.p.h. of an auto, measuring the radial forces exerted on said drum by said tire, measuring the dynamic unbalance forces of said wheel/tire, and utilizing said measurements.

Claim 13

The method of simultaneously testing the symmetry and non-uniformity characteristics of a vehicle wheel/tire utilizing a drum to obtain simulated actual static load and speeds characteristic of 60-90 m.p.h. comprising steps of: supporting said wheel/tire and said drum in a fixed distance closed loop arrangement upon parallel axles, varying the position of said drum to simulate a static load on said drum and thereby creating a tire patch, rotating said drum at peripheral velocities characteristic of 60-90 m.p.h. of an auto, measuring the radial forces exerted on said drum by said tire, measuring the dynamic unbalance forces of said wheel/tire, and utilizing said measurements.