Leonardo da Vinci designed a screw jack mechanism to raise heavy loads.
A screw jack uses the mechanical advantage of a threaded screw: turning the screw converts rotational motion into a slower, powerful lifting motion. Leonardo studied and drew versions of this principle while investigating machines for construction, engineering, and military work. The device could lift heavy objects more controllably than direct human force.
Leonardo’s notebooks contain many studies of screws, gears, and lifting arrangements. His interest was not limited to one finished product; he analyzed how parts could transmit force, multiply effort, and operate reliably. This makes the screw jack a useful example of his approach to mechanical design.
The term should not be confused with a modern automobile jack, although modern vehicle jacks may use the same basic screw principle. Leonardo did not invent the screw itself, which was already an ancient technology. His contribution was the detailed Renaissance study and application of mechanisms built around it.