Drum brake device having leading/trailing mode and duo servo mode

摘要

Disclosed is a drum brake device in which during a service brake application, a pair of brake shoes operates in a leading/trailing mode, and during a parking brake application, a parking brake mechanism operates to cause the brake shoes to operate in the duo servo mode. A first lever, an equalizer and a second lever, which make up the parking brake mechanism, are all assembled onto one of the brake shoes. The second lever includes an input portion, a lever contact portion and an equalizer contact portion. The input portion receives a force from a parking lever. The lever contact portion applies a turning force to the first lever. The equalizer contact portion applies a turning force to the equalizer. The second lever, when it is turned, turns the first lever and then the equalizer.