PURPOSE: To reduce a manufacturing cost with a simple construction and to promote deceleration brake performance by fitting an accelerating rotary body having a vibrating body coming into contact with the circumferential surface of a rotator with the increasement of a revolution speed of the rotator to the outside of a stator.

CONSTITUTION: An accelerating rotary body 4 counter rotating is fitted to the outside of a stator 2, a vibrating body 5 to be pivoted to the rotary body 4 is projected in the direction of A according to the increasement of a revolution speed of the accelerating rotary body 4 through a planet gear in case of taking-up and housing, and the vibration is braked by coming into contact with the circumferential surface of a rotator 1. The vibrating body 5 pushes a rotary body 6 as the arrow B and, at the same time, it is brought into contact with a brake disc 8 to which hard rubber 9 and others are loaded to push, so that damping force acts through a clutch holder 14 and a one-way clutch 10 fixed to the stator 2.