Patent ID: 9709114
Date: 2017-07-18
CPC Classifications: F16D

Claim:
1. A vented brake drum comprising: an annular hub portion and drum portion having a cylindrical shape, a circumferential outer surface, and a cylindrical internal braking surface against which a brake lining of a semicircular brake shoe can be frictionally engaged for braking; and a series of spaced-apart oblong openings oriented circumferentially along the internal braking surface and extending depthwise through the drum portion from the outer surface to the internal braking surface, the series of oblong openings being distributed in a diagonal pattern that is repeated circumferentially around the drum portion; in which each diagonal pattern of oblong openings is in the form of a helical line oriented diagonally across the internal braking surface, each of said patterns positioned in a different circumferential section of the drum such that a single one of each of the oblong openings occupies a unique circumferential position on the drum.