Internally ventilated brake disk rotor

A vented brake disk comprising at least two parallel ring disks connected with each other by a repeating series of ribs having a series of at least two major ribs. Further, (a) between each pair of these major ribs, there are at least three further ribs (b) between the ribs, there are ducts having an irregular distribution of cross section area, (c) the inner part close to the rotation axis of the major ribs has the shape of a cudgel, (d) the part of the outline of a major rib in a zone close to the inner circumference has at least two radii where at least one is larger than 12 % of the inner radius of the brake disk ring, (e) the outer contour of at least one rib has a reversal point, (f) the angle ± between the radius through the reversal point on the flank of at least one rib F mn opposite to the direction of rotation of the brake disk ring, and a straight line connecting this reversal point with the centre point of a circle circumscribed within the inner end of the rib immediately following this rib F mn is less than 90°, and (g) at least one of the ribs is formed of at least two parts.