Patent ID: 7326119

Claim:
A boot for a constant velocity joint, the boot comprising: a minor-diameter cylinder to be held to a shaft; a major-diameter cylinder separated away from the minor-diameter cylinder, disposed coaxially with the minor-diameter cylinder, and having a larger diameter than that of the minor-diameter cylinder and a noncircular inner peripheral cross-section, the major-diameter cylinder to be fastened to a mating member by diametrically reducing a fastening member inward around an outer peripheral surface of the major-diameter cylinder; and a bellows connecting the minor-diameter cylinder with the major-diameter cylinder integrally, and formed as a truncated cone shape substantially; wherein the major-diameter cylinder comprises: a sealing protrusion rim formed on an inner peripheral surface of the major-diameter cylinder; a plurality of flanges disposed at intervals in a peripheral direction of the major-diameter cylinder, and extending axially outward from an opposite end surface of the major-diameter cylinder; and a positioning protrusion protruding from the flanges radially toward an inner peripheral side of the major-diameter cylinder, and to be engaged with a concavity formed in an outer peripheral surface of the mating member.