Which Leonardo da Vinci design used a screw mechanism to lift heavy objects?

Leonardo da Vinci’s screw jack used a screw mechanism to lift heavy objects. His notebooks contain studies of screw-based lifting devices, applying the mechanical advantage of a threaded shaft to construction and engineering problems.

When a screw is turned, a small rotational movement produces a larger force over a short vertical distance. That trade-off makes it suitable for raising heavy loads gradually and holding them in position. Leonardo’s designs explored how gears, handles and threaded components could make lifting more controlled than simply pulling with a rope.

The screw jack was not a single standardized machine with one universally accepted historical model. Leonardo drew several related mechanisms, so modern references may describe them as screw jacks, lifting screws or screw-based hoists. The general principle was much older than Leonardo; ancient engineers used screws for pressing, raising and moving materials. Leonardo’s importance is that he documented and refined mechanical arrangements in detailed Renaissance studies, not that he invented the screw itself.