Leonardo da Vinci designed a screw jack using a threaded screw to raise heavy loads.
Leonardo’s mechanical studies include screw-based lifting devices in which turning a handle moves a load upward along a threaded shaft. The principle trades speed for force: a relatively small effort applied over many turns can produce a much larger lifting force over a short distance.
This idea belongs to the broader Renaissance development of practical machines for construction, workshops, and military engineering. Leonardo studied screws alongside gears, pulleys, winches, and other devices, often analyzing how motion and force could be transmitted through mechanical parts.
The screw jack should not be confused with a hydraulic jack, which uses fluid pressure, or with a simple pulley, which changes the direction or mechanical advantage of a rope. Leonardo’s design relies on the inclined plane wrapped around a cylinder—the basic mechanical principle of a screw.