5.1 DIRECTION CONTROL:RATCHETS:
A rached is a mechanism that controls the direction of motion.Some ratchets are reversible,so they can turn and lock in one direction or another.

5.2 SPEED REDUCTION:BRAKES:
Brakes use friction to reduce speed.They are activated by certain levers.The lever transmits forcé to an output receptor,which puts pressure on the Wheel.There are various types of brake systems according to where the friction is produced:

• Disc brakes:A disc is connected to an axle.Brake pads apply pressure to the disc.
• Band brakes:A drum is connected to an Axle.A flexible band applies pressure to the outside of the drum.These brakes were used in carriages and they depended on the strength of the driver.
• Drum brakes:A drum is connected to the axle.A pair of brake shoes apply pressure to the inside of the drum.