Leonardo da Vinci designed a screw jack to lift heavy loads through the mechanical advantage of a screw.
A screw jack converts rotational motion into slow, powerful linear movement. Turning the screw raises or lowers a platform, while the thread helps support the load and resist reverse motion. Leonardo’s mechanical drawings include screw-based lifting arrangements intended for construction and engineering work.
Such a device could help raise heavy materials more precisely than direct lifting. The idea fits Leonardo’s wider investigations of force, gearing, threaded mechanisms, and machines for building. A screw jack is especially useful when controlled movement matters more than speed.
The design is not simply a pulley or winch. Pulleys and winches typically lift loads using ropes, drums, and wheels; a screw jack supports the load through the threaded screw itself. Leonardo’s contribution was a Renaissance study of a practical lifting mechanism rather than the invention of the screw as a general object.