Leonardo da Vinci designed a screw jack to raise heavy loads.
A screw jack converts rotational motion into lifting force. Turning a threaded screw moves a load-bearing component upward or downward, allowing a relatively small input force to raise a substantial weight. Leonardo studied such mechanisms as part of his wider work on machines, gears, threads, and construction equipment.
The screw jack belongs to a long history of lifting devices rather than being a completely new principle invented from nothing. Ancient engineers used screws and related mechanisms, and Renaissance designers refined their applications. Leonardo’s contribution was his detailed analysis and inventive combination of mechanical parts in drawings intended for engineering and construction.
A screw jack is different from a pulley or crane. A pulley changes the direction or mechanical advantage of a rope, while a screw jack provides lifting through the rotation of a threaded member. Leonardo’s machine studies frequently examined this kind of mechanical advantage, using geometry to explain how motion and force could be transformed.