Patent ID: 7044275

Claim:
A drum brake device comprising: a first and a second of brake shoes arranged in a drum being opposed to each other; an operating force generator for generating a shoe operating force to push the brake shoes to the drum so as to generate a braking force; and a shoe drive cam, for controlling the braking force by utilizing a reaction force given to the brake shoe at the time of applying the brake, including: a first and a second cam pins, wherein each cam pin contacts with an end portion of each brake shoe; a cam plate pivotally supported by an anchor pin perpendicularly arranged on a backing plate, wherein the cam pins are inserted into the cam plate, and wherein gaps are provided between the cam plate and the cam pins; and a lever plate having an input force receiving portion for receiving the shoe operating force, a first pin engaging portion with a curved convex for contacting with the first cam pin, and a second pin engaging portion with a hole-shape for engaging with the secondary cam pin, wherein the lever plate is connected to the cam plate rotatably around one of the first and second cam pins.