Leonardo da Vinci designed catapult mechanisms to fling stones using stored mechanical energy and a throwing arm.
His military notebooks include studies of machines that could store energy in bent wood, springs, or other elastic components. Releasing that energy moved an arm rapidly and launched a projectile. Leonardo examined the geometry and force needed to make such weapons more effective.
The word “catapult” covers several types of ancient and medieval throwing machines. Leonardo’s studies therefore represent an investigation of a broad weapon family rather than one single standardized model. Some designs use torsion or elastic force, while a trebuchet uses a counterweight.
Leonardo also drew other siege weapons, including giant crossbows and bombardment machines. These should not be merged into one invention: each uses a different method to store and release energy.