Leonardo da Vinci designed a screw jack, a lifting device that raises a load through a threaded screw.
A screw jack converts rotary motion into vertical movement. Turning a handle rotates the screw, and the threads force a platform or nut upward or downward. This gives mechanical advantage, allowing a relatively small turning force to lift a heavier load over a short distance.
Leonardo’s engineering notebooks include a design with a large spiral screw and a platform for raising materials. The device belongs to a long tradition of screw-based lifting machines, rather than being an entirely new physical principle invented from nothing.
The same principle remains in modern mechanical jacks, including some vehicle jacks. Hydraulic jacks use fluid pressure instead, so they should not be confused with Leonardo’s mechanically threaded design.