Patent ID: 7331433

Claim:
A brake disc for a vehicle, which disc is supported by a wheel at an inner peripheral portion thereof through a plurality of support members and is operable to exert a braking force when sandwiched by frictional pads, said brake disc comprising: inner and outer peripheral faces, the outer peripheral face having a plurality of spaced circular face arc portions with a respective length concentric with an axis of rotation of the brake disc; a plurality of outer recesses are defined in the outer peripheral face so as to deploy in a circumferential direction; and a braking surface engageable with the frictional pad and having a radial width that varies in a direction circumferentially thereof, wherein each of the outer recesses has a bottom having circular bottom arc portions with a respective length concentric with the axis of rotation of the brake disc, and each of the outer recesses opening have sloping surfaces extending radially outwardly along a circumferential length increasing progressively in a direction radially outwardly from the bottom circular arc portion to an adjacent outer peripheral face circular arc portion, wherein the number of the outer recesses is equal to or greater than that of the support members.