Patent ID: 8869953

Claim:
A brake disc for a vehicle, comprising: first and second friction rings; a plurality of ribs arranged between the first and second friction rings and extending essentially in a radial direction forming air cooling ducts bounded by side walls of the plurality of ribs, wherein at least a majority of said plurality of ribs have both side walls arranged substantially perpendicular with respect to friction surfaces of the first and second friction rings, wherein exactly one, two, three or five of said plurality of ribs have at least one side wall inclined with respect to the perpendicular ribs, and wherein for at least one of the ribs having at least one inclined side wall, a rib thickness measured in a direction perpendicular with respect to the side wall differs from a thickness of the perpendicular ribs such that a rib mass of each rib of said at least one rib having at least one inclined side wall is equal to a mass of each of the perpendicular ribs.