Patent ID: 7377300

Claim:
An elastic tire with a tread, wherein the tread comprises at least one unit for measuring grip of the tire on a surface on which the tire rolls, the at least one measuring unit being configured to come into contact with the surface on each revolution of the tire, the at least one measuring unit comprising, viewed at a radially outer face of the tread, a central zone and an encircling zone surrounding the central zone, and a sensor sensitive to at least a tangential force exerted on a radially outer top of the central zone, the sensor being provided below the radially outer top of the central zone, the central zone and the encircling zone satisfying conditions of: a) Rzz c <Rzz e , and b) (i) Rxz c /Rzz c >Rxz e /Rzz e or (ii) Ryz c /Rzz c >Ryz e /Rzz e , wherein x, y, and z respectively represent circumferential, axial, and radial directions for the tire, wherein Rzz c and Rzz e respectively represent rigidities of the central zone and the encircling zone under a force oriented perpendicularly to the radially outer face of the tread, wherein Rxz c and Rxz e respectively represent rigidities of the central zone and the encircling zone under a force oriented tangentially to the radially outer face of the tread in the circumferential direction of the tire, and wherein Ryz c and Ryz e respectively represent rigidities of the central zone and the encircling zone under a force oriented tangentially to the radially outer face of the tread in the axial direction of the tire and wherein the encircling zone comprises a first tread element separated from the central zone by a sipe and a second tread element separated from the central zone by an incision having a width less than that of the sipe.