Crank -

Cranks became common for water-driven sawmills, cranes, and spinning wheels.

When combined with a connecting rod (conrod), it changes linear movement (like a piston moving up and down) into rotation.

A crank consists of a crank arm (or web), a shaft (or axle), and a crank pin.

Cranks can be powered by hand (e.g., a winch) or foot (e.g., a bicycle pedal). 2. Key Examples & Applications

Evidence of hand-cranked rotary handmills appeared in Spain (5th Century BC) and later Greece. A 2nd-century AD Roman iron crankshaft was found in Switzerland.