Leonardo da Vinci designed a screw jack with a screw mechanism for raising heavy loads.
A screw jack converts rotary motion into controlled linear lifting. Turning the screw moves a supporting platform upward or downward, providing mechanical advantage and allowing a relatively small force to raise a substantial weight. Leonardo’s drawings show his interest in improving such mechanisms through threaded screws, gears, and supporting frames.
The device fits naturally into Renaissance construction and engineering, where heavy stones, beams, and machinery had to be positioned accurately. A screw jack is slower than some lifting systems, but it can hold a load securely and make fine adjustments.
Leonardo did not invent the screw principle itself; ancient engineers had already used screws in presses and water-lifting devices. His contribution was to study and refine mechanical arrangements for practical lifting. It is also distinct from a crane, which usually uses a boom, rope, and pulley to raise loads.