Abstract: A brake assembly by means of which rotational motion and also linear motion, i.e. faulty motion of lifting platforms, especially dropping, is braked. The assembly comprises a braking gear (20, 21) fitted onto axle (4), a coupling (25, 26) to transmit rotational motion and furnished with a locking device (27) that releases by an adjusted rate of centrifugal force generated by the rotational motion and locks the coupling to transmit rotational motion between the axle and the locking device. Upon locking, the locking device in the coupling is fitted to transmit rotational motion also in the opposite direction of the direction produced by the locking device in order to open the locking device by turning axle (4) in the opposite direction, and the coupling has a retaining shoulder (50) to prevent the locking device from returning immediately to an unlocked position when the brake is opened by rotating axle (4) in the opposite direction.