a> At normal speeds, pinion is normally driven by rack, and centrifugal block is rotated along with gear wheel shaft under the force of spring.
b>  When it goes beyond a fixed speed, the centrifugal weight is thrown outwards and connects the pinion to the brake cone.
c>  With the holding together of inner and outer cones, braking moment increases progressively , so the cage can stop smoothly and steadily,while stopping the cage, the main power supply will be cut off automatically
Then it is restored to the original state for restarting.