Leonardo da Vinci designed a catapult with a large curved throwing arm and a winch.
His military notebooks include several studies of artillery and siege machines. In this catapult design, a winch pulled the throwing arm back and stored energy before release. The arm then hurled a projectile toward a target, following the general principle of tension-powered siege weapons.
Leonardo did not invent the catapult. Ancient Greek and Roman engineers had already developed several families of catapults centuries earlier. His contribution was to analyze and redesign military machines using detailed drawings, mechanical linkages, and proposed improvements to their operation.
The catapult should not be confused with his giant crossbow or his trebuchet-like stone throwers. Those machines used different arrangements for storing and releasing energy, even though all were intended for siege warfare.