FIELD: tyre industry. SUBSTANCE: invention relates to design of automotive tyres. Tyre envelope used on rim with nodule consists of upper part, two flanges and two edges and at least one covering of carrying structure passing from one edge to the other. Each edge has main bead-forming ring around which covering of carrying structure is arranged, and secondary bead-forming ring located outside the covering of carrying structure. Inner diameter of main bead-forming ring after mounting on rim is greater than diameter of upper part of nodule. Inner diameter of main bead-forming ring before mounting on rim is practically the same as after mounting on rim, and maximum elastic elongation of main bead-forming ring is 1.5%/ Outer diameter of secondary bead-forming ring before mounting on rim is less than inner diameter of main bead-forming ring, and after mounting on rim, inner diameter of secondary bead-forming ring is less than diameter of upper part of nodule, and inner diameter of secondary bead-forming ring, after mounting on rim, is greater than inner diameter of secondary bead-forming ring before mounting on rim by 1.5-3%, maximum elastic elongation of secondary bead-forming ring is less than 3%. EFFECT: increased reliability and safety of tyre. 4 cl, 3 dwg
