| 摘要 |
PURPOSE:To enhance the working effectiveness in mounting and removal at the time of rim assembling and prolong the lifetime by furnishing a bead part with a bead base consisting of a near-to-heel situated region having an inclination angle over 15 deg. and a non-inclined region ranging from the middle between the heel and toe till the toe, and giving the near-to-toe inside dia. a value between 95 and 97% of the nominal dia. of rim. CONSTITUTION:Chafers 4, 5, 6 of steel, nylon, rubber are arranged on the periphery of a radial carcass 1 made from steel cords having a winding-back 3 around a bead core 2. The bead part B has a bead base consisting of a near-to-heel situated region 9 having an inclination angle equal to or greater than the base angle 15 deg. of a seat base of a rim and a near-to-toe situated region 10 which is free of inclination ranging from the middle between the bead heel 7 and bead toe 8 till the bead toe 8. The inside dia. D of the bead heel 7 shall be a little smaller than the nominal dia. of the rim, while the inside dia. of the near-to-toe region 10 shall range 95-97% of the nominal dia. of the rim. This permits improving the working effectiveness in rim assembling and giving excellent durability to the bead part B. |
