TIRE WITH CAVITIES IN BEAD REGION

摘要

the present invention relates to a pneumatic tire, specifically to improvements to the bead region of tires designed for runflat operations. The improvements comprise the addition of cavities or indentation (126) on the surface of the bead (127) that contacts the wheel rim (128). In a first embodiment a series of circular cavities (126) are located on the radial innermost surface of the bead in the proximity of the bead toe. In a second embodiment, a continuous groove-like torus cavity (226) is located in the radially innermost surface of the bead in the proximity of the bead toe. The series of cavities or torus cavity increase the adherence of the bead to the rim as a small volume of air at a low pressure, significantly inferior to the atmospheric pressure (air vacuum situation) is trapped in the void spaces created by the cavities or torus cavity and the bead seat.