Leonardo da Vinci designed a screw jack, a lifting device that uses threaded motion to raise heavy loads.
A screw jack converts rotation into slow, powerful linear movement. In Leonardo’s design studies, a screw and drum mechanism could be turned to lift or adjust heavy objects with greater control than direct human lifting.
The principle was already related to ancient screw technology, but Renaissance engineers applied it to construction, military equipment, and workshop machinery. Leonardo’s contribution was his detailed analysis of mechanisms and his habit of combining screws, gears, and frames into practical systems.
A screw jack differs from a pulley crane, which lifts through ropes and wheels, and from a hydraulic press, which uses fluid pressure. Leonardo’s notebooks contain many mechanical lifting concepts, so the exact drawing and terminology matter when identifying the device.