Ratchets are mechanisms that serve to limit either rotary or linear motion to only one direction. Ratchet designs vary but the basic composition of parts is fairly universal.
Ratchet, mechanical device that transmits intermittent rotary motion or permits a shaft to rotate in one direction but not in the opposite one.
A ratchet is composed of three main parts: a round gear (or a linear rack), a pawl (also called a “click”), and a base (or mount).
The geometry of the gear or rack is usually designed with a ramp feature on one side of the tooth leading to a sharp drop off which restricts motion of the pawl when the linear or rotational direction is reversed. Most ratchet mechanisms are not very large as only a small vertical wall is needed to prevent motion in one direction.
The apparatus gives the detailed information including the working of the ratchet mechanism. The apparatus is movable and very easy to use. The mechanism is fitted on the Bakelite base board with rubber foots.