Patent ID: 7077249

Claim:
A drum brake comprising: a drum, a backplate, at least one interconnected shoe mechanism and an automatic adjusting mechanism for adjusting brake clearance; the interconnected shoe mechanism comprising a first composite shoe and a second composite shoe each having multiple degrees of freedom, the first composite shoe comprising a first shoe and a first driving lever and the second composite shoe comprising a second shoe and a second driving lever, wherein the first and second shoes are rotatably joined to respective first and second driving levers at respective first and second shoe joints; the first and second driving levers each being pivotably supported on the backplate at respective first and second anchor joints; wherein the first and second driving levers of the first and second composite shoes are arranged in the directions opposite to each other, a tip of the first driving lever and the second anchor joint being located on a same side and a tip of the second driving lever and the first anchor joint being located on an opposing side, and the first and second anchor joints being separated by a distance; and a slide joint mechanism for interconnecting the first and second shoes of the first and second composite shoes at their adjacent ends to maintain the first and second shoes at the same radial displacement at the slide joint mechanism and allowing limited free movement in a circumferential direction; the automatic adjusting mechanism being fixed on the backplate and interconnected with the first or second driving lever to keep substantially constant clearance between the first and second shoes and the drum as linings of the first and second shoes wear.