Leonardo da Vinci designed screw-jack mechanisms that used a threaded screw and supporting structure to raise heavy loads.
A screw jack converts rotational movement into slow, powerful vertical movement. Leonardo’s mechanical studies examined screws, gears, and lifting systems, showing how a worker could gain force at the expense of speed. Rollers or wheels could help position the apparatus and reduce friction while a handle turned the screw.
The screw jack was not an entirely new principle in Leonardo’s era; screw-based lifting devices had earlier precedents. Leonardo’s notebooks are valuable because they document detailed mechanical arrangements and practical applications. His design should also be distinguished from his Archimedes’ screw water-lifting studies, which moved water rather than raising a solid load.