| 摘要 |
PURPOSE:To make it possible to produce a boot with performance equivalent to one having ribs on the internal periphery of a ring by blowin molding by making the internal periphery of the ring on small diameter side mounted on a joint shaft side in the shape of stair-case moats formed along a virtual convergent conical trapezoid. CONSTITUTION:The internal periphery of a ring 2 is formed in the four steps of the shape of approximate stair-case moats formed along a virtual convergent conical trapezoid. In addition, the periphery of the ring 2 is formed in a tapered shape having the same inclination as the virtual conical trapezoid 8 drawn by the tips of the stair-cases formed on the internal periphery of the ring 2. The ring 2 of a boot 1 formed by injection blowin-molding is fitted in the fitting groove 4 of a joint shaft 3 enlarging a diameter on the outside end of the ring 2, and fixed by a clamping member 5. In this state, the tips of the stair-cases formed on the internal periphery of the ring 2 act for ribs to improve sealing ability between the joint shaft 3 and the ring 2. |
