Patent attributes
In a joint boot to be mounted on an outer housing having a non-circular outer peripheral configuration, the invention is designed for ensuring a high sealing capability without impairing the moldability. To that end, its large-diameter attachment part to be attached to the outer housing is configured, in its internal peripheral contour, to bulge radially inwardly in plural circumferential places thereof so that bulging portions each include an inner wall portion radially inwardly bulging in a curved form, an arc-like outer wall portion constituting part of an outer peripheral face of the large-diameter attachment part, a radially extending central strut wall linking these inner and outer wall portions in peripheral centers of both, and lateral strut walls linking on both sides of the central strut wall the inner and outer wall portions. The lateral strut walls are slanted such that their outward parts approach the central strut wall.