Leonardo da Vinci designed a screw jack, a lifting device that raises heavy loads through a threaded screw.
A screw jack converts rotary motion into vertical movement. Turning the screw moves a load-bearing nut or platform along the threads, giving mechanical advantage and allowing a relatively small force to lift a heavy object. Leonardo studied screw-based mechanisms extensively and drew lifting devices for engineering applications.
The screw jack is distinct from Leonardo’s aerial screw, which was a proposed flying machine. Both use helical geometry, but they served entirely different purposes: one lifted loads while the other was intended to generate upward motion. The basic screw principle itself was much older than Leonardo, with ancient Greek engineers using screw mechanisms.
Leonardo’s contribution was his detailed mechanical analysis and his adaptation of known principles to practical machines. His notebooks include cranes, hoists, and other devices designed to reduce labor in construction and military engineering.