What lifting device did Leonardo da Vinci design with a screw mechanism?

Leonardo da Vinci designed a screw jack, a lifting device that uses a threaded screw to raise a heavy load.

A screw jack converts rotational motion into controlled vertical movement. Turning the screw advances a platform or support upward, allowing substantial force to be applied slowly and accurately. Leonardo’s notebooks contain studies of screw-based mechanisms used for lifting and mechanical advantage.

The design belongs to a long history of screw mechanisms rather than representing an entirely new principle. Ancient Greek engineers, including Archimedes, had already used screws in devices such as water pumps. Leonardo’s contribution was to examine mechanisms systematically and adapt them for practical engineering problems.

A screw jack is different from a hydraulic jack, which uses pressurized fluid. It is also different from a windlass, which raises loads by winding a rope around a drum. Screw jacks remain useful where precise, stable lifting is required.