Patent ID: 7290641

Claim:
A brake device for a power tool, having a brake assembly, a bearing portion, a pinion and a gearbox, and characterized in that: the brake assembly comprises a brake base, a cover, a first throttle cable, a second throttle cable, a brake-activating block, a brake-guiding pillar having an end contacting the brake-activating block, a brake band and a brake drum; the brake drum is connected to the pinion, and the pinion is connected to the gearbox; one end of the first throttle cable is connected to a carburetor, and the other end thereof is connected through a spring to one end of the brake-activating block; one end of the second throttle cable is connected to a throttle, and the other end thereof is connected to the other end of the brake-activating block, such that the first throttle cable, the brake-activating block and the second throttle cable are linearly connected together in series; an end of the brake-guiding pillar not contacting with the brake-activating block is connected to the brake band, and the other end of the brake band is fixed to the brake base; and a spring is provided on the brake-guiding pillar, and the length of the brake band is designed to tightly surround the brake drum for stopping the rotation of the brake drum; wherein the abutting or separating state between the brake band and the brake drum is able to be controlled by a relative movement among the first throttle cable, the brake-activating block and the brake-guiding pillar.