Patent ID: 7628252

Claim:
A drum brake, comprising: a brake drum rotating in a first direction; one or more brake shoes; and wherein when said drum brake is applied, said one or more brake shoes are caused to rotate in a direction opposite of said first direction and said one or more brake shoes engage with said brake drum to bring said brake drum to a stop wherein the brake further comprises a brake-oil hose, an annular-oil cylinder, an annular piston, a push disc, a push rod, and a brake-primary piston; wherein an end of the brake-oil hose is inserted in the central hole of a planetary gear axle of a planetary gear; an end of the planetary gear axle is inserted in the annular-oil cylinder; an annular-oil shell is formed between the annular-oil cylinder and the annular piston and is connected to the central hole of the planetary gear axle; the annular piston is connected to the push disc; the push disc is connected to an end of the push rod; and the other end of the push rod is connected to the brake-primary piston.